SeanLActine ett’ o wet thackaden Wede 0 we net . ae in i 3 - = . = ats ro pahev ee. } eet vere _ M = * a > ipreue NER re ty = ey ea LA ein Neti g AO TU Dm, Aon son to wabere oh hanawionentmwiahiadigidieee ieinine tel stb ubukceed = = 4 ta oe rt my Tuctrtetisestasistaca name ateataailerien tice re remo maven pene — “hy ie 9 vate te, * Peder Saath =i 9 as re “ap barat hvala ate fins tohehutuhwreinaverreyese: totees . std a * hs Lis ted has ge bt OV eee a eth yer te nie Ty oLerryer tp rebihe “ { ah — vee net wish Pherae: i. is Popular Science Monthly | Volume 90 January-June, 1917 Modern Publishing Company 239 Fourth Avénue New York ] by c ‘rights reserved eae 1917 1108 All Cop, j ee MODERN PUBLISHING COMPANY =— P l 9c] Monthl Volume 90—January-June, 1917 AERONAUTICS . Page Page Ruth Law Makes Record Flight............--- AS ‘. ee FRR PROMS Pesce iaes cose c's res Peadi: *Twixt Earth and Sky from a Zeppelin. (OES (CES Se errs oot eee whe puent Masi... ....+5-. ss 3 Sieavare ack m - _... 369 A Hollow Waterproof Tile Building Block........ 679 Motor Goose........ eats A World’ s Fair Skyscraper...........--.--+--- 716 A Bird-like Airplane é Bi UGeaee Patch Toes. c5 ccs es es ye Se 807 Ruth Law’s Wiisinee is Reducing Fire Ae i ERE a ee eee RE TE 868 The Cavalry Horse of the Air............--.--- 397 ~—s— Protecti Canal Zone Buildings with an Oil Maki Pace Airplane Tire . Hundred Per Cent Dasat foe mechs... 2S tG son is ee ee 882 AES Beast es Se ee rs ee eth A favo That Served as a Home and Is Now a Band- 4 Searchlig reed Watching for Airplanes............ 490 stand... .. 21.2... eee e cece reece eee eee e eee another at Bird-Men with the New French Guns ata A Cieu-ecaith GM oa ata sek ees oc 931 Why Zeppelins Are Frightful..............---- The Aerial Loa el LS gr POR oO 342 ASTRONOMY Plow Aviators op eller Made on 1121 680 The Most Wonderful World in the Universe... .. 264 To from an Airplane..........---+-+-- 690 Is Space Itself Luminous?..............-.---+-- 271 steep ylinder Airplane Engine............ 696 ee ee On ee ee ee 903 Nn Shock-Absorbing Airplane Wheel...........-. 855 Adding the Motorcycle to Airplane Equipment... 864 CHEMISTRY Chemistry—An Important Factor in Criminology 42 AGRICULTURAL SCIENCE Making Imitation Leather from Paper Preparations 113 Tempering the Wind to the Farm with Trees. 30 # A Mixture for Cleaning Paint.................. 121 Drennan e eur Caer oad hs ESL. 2 o's oe 55 Chemically Hardening — paleens- eet Floors. 302 How the Forest Service Gathers Pine Seeds...... 67 A Vest-Pocket Sterilizer < . ... 2.0.2 50008 00s cee one 400 Making the Automobile Do the Chores.:....... 119 Potash from ecuedeaks Industry in the Making 575 A Knitti Needle ssameatie for Testing Milk....... 146 How Paints Are Made............-----2-2-00- 593 . et icmentheunnnieh. <0 ties aig. 169 _ Goggles to Be Used When Making Chemical Expe- 3 Shipping Day-Old Chicks Is Is Profitable at Both Ends 190 NS See ee ty eee 610 sg, ise ar Harness for the Workman . 194 — Oxidizing Iron with Fumes fromAcids.......... 612 Rares Potatoes on the Roots of a Tomato Plant 203 ne a ES | ee ee eee 680 Taking Care of Honey Bees During the Winter... 206 Dried Vegetables..............-+2.-+-2--+---- 698 Wall Street Goes a-Farming..................- 233 Another Outcome of the War—The American Comfortable Cork Brick Ficorin for Cattle...... 255 Evaporated Vegetable................+..-. 27 New Cream Separator Gover is Based on Novel Writing Paper Made from Spinach Stems........ 742 EA ES See oe ee ee re 423 Making Artificial Cream that Rivals the Original.. 749 Mothering Orphaned Animals with a Make-Believe Phe Wonders of Coal Tati) ois sax iewpiceedscss 874 IR a gh Ra eres ibn dt olin ea cea <'a/0% 437 Ps mpm Method of Handling Dangerous rn Conveniences on the Farm............. yo Beek * See ee eee ee eee ee ee 929 The Amount and Distribution of Water ona Farm 451 Malang a Paint That Will Stand Washing....... 930 A Bulletin Board for Making Sales of Farm Produce 463 etin rd for Making Sales arm Produce : A Method of Keeping a Rabbit’s Cage Clean.... 464 CIVIL ENGINEERING j Stimulating a Plant’s ““Digestion’’ by Electricity. . 510 Laying Pipes in a New Zealand River........... 40 Making Hogs Grind Their Own Grain Food..... 511 Endangering Your Life for an jmeainary Line... 99 Quartering g Potatoes for Seed with a New Double- A Wooden Cinders OF Over the Desert........-.. 116 Blade C nS A ee ne ee ee ee 596 Suppose New York’s Harbor Were Drained...... 164 Converting an Automobile into a Farm Workhorse 598 France Completes the World’s Largest Tunnel. 197 An ‘om Constructed Pan for Sterilizing Dairy Protecting San Francisco’s Beach.............. 259 RIE eo olds cine ee ee we Sb 6 ess bos Skee Xb 617 Widening a River with a Steam Shovel......... 343 A * pore Waterpot and Hoe...............- 728 How the Office Adding Machine Is Employed in Portable Saw and Pump Outfits..............-. 746 SRNR Sc ki as kA SE elas lao i mealcce Liaw 6 oe we 348 Grow Potatoes in Window-Boxes............... 746 The Spaulding Re Re rer ee 507 Coaxing Birds to Your Garden.................. 756 .: c Highways Under the Hudson River ...... 508 : Making a Small Colony Poultry House.......... 776 A Grass Bridge. A Remarkable Feat in Civil ; Planting Strawberries by Machine............ 870 po OS ATE rn Se SET a ee eee 564 ;, Plowing the Farm by Automobile.............. 881 How Baltimore Protects Newly Paved Streets and Enveloping Trees in Freezers to Study Tempera- Saves Time and Trouble................+++. 596 S RED inten 5 82a ne CEO Se Or Fe Welders SS vce 882 It’s Sheer beer That Keeps a Pier in Place.... 600 = Dtaimbae ENO CLOW 24. ic o's oso oils a hoe we te 892 —- CL Cie Ohi asia ha Wot d fades an Auditorium of Echoes............... 241 Seeing the Sounds That You Sing. .............. 29 _ A German Village on American Soil............ 424 An Electric Light Attachment for Eye-Shades. . 30 : A Million-Dollar Schoolhouse... ............++++ 496 Finding the Keyhole at Night...............++- 60 3 4 a ™ a Page An Ingenious Rain Alarm. ........¢0...-0.2e08- Weed Se 4 Illuminating the pans PAGS cuince sc cera dwn 72 hat One Penny Will Buy in es Service.. 73 A Small Backyard Sanrchieh RPE A TG ey ear On tM 121 Thawing Frozen Water-Pipes Electrically....... 145 An Electric Alarm Signal 8 the Fisherman..... 149 Estimating the Windings of the Electromagnet Oe) SER pen ary Urn warn re Sey oe 150 A Means of Indicating the Location of a Bell Call 151 Combining the Telephone Receiver and Trans- mitter in One Instrument.................. 187 Next Summer's Ice. with Electricity..°2 255%. scene aes ee oP aS 197 A Flashlight to Show the Position of Talking- achine: Needles : << 536-537 Li OES a eet eet era ie yt Strap it on Your Neck and Cut Your Hair ‘Yourself 565 os Spd: heard This Electric B w as It Cuts a Re ee i ee eee 569 A potaae Spray — a opi Slot Machine.... 579 es by the Sky Route........ eee at 581 53 he en — a Buzz-Saw—That’s the ane A Machine Which Aucomatically Feeds Twine and It Takes Pear Thousand Characters to Typewrite pen Foilin Torpedoes with Whirling Plates......... 643 Hands M Mechanical Appliances.............- 694-695 ee eee Mini MRE... cots atta eo vnc te see pe 702 rae ae es an Hour. = NP TE Sg ee a ge gt actory neering Course.......... er nsd Wied Us thc Chock. 200 725 Exit the a sername A A ele: Sine arr era 736 A Mine-Car Which Unloads Itself... ..........- 737 A Bri of Cables, and Chicken Wire 760 A One-Man Tree-Felli oS CS PC OR New Mechanical Appliances..............-- 852-853 Mail with Py er Wan Ses: oes eee 854 A Re-Inking Typewriter Roller................-- 855 A “Community” Power Plant........-...-...-- 867 Drilling Holes in Concrete on a New Principle... 891 The ene, ool eves a Measures Out ater to the ey Mbeya Ee oaks pasink ne 9 This Contractor es Tis ered Shop to His Job 895 gy area i a Steamer by the Marine Elevator.... 908 A ony Electric Crane with the Strength of a i MEDICINE, SURGERY AND HYGIENE Don’t coe the Dog—Help Him as If He Were MERE re Bet SES OO oo Ie Sb ooo pees 3 A New Method of Identifying Infants.......... 41 a ae stage Bde arness for the Wounded......... 47 t Massages Your Pains Away..... 66 Stecpin on . Mattress Filled with Water....... 66 ery Time We Wink We Give the Eyea Bath.. 68 of the Teeth 1 How Much Ough A Fountain Tooth Brush Mr. Average Healthy Man's Enormous Appetite... 195 mbination —— and Toothbrush Holder... . bigs A Sor ag Bee eee oa cas ub eae ole 16 Simple Meth for E Pasteurizing Milk Sener ore 216 Food Inspection in New York.............. 222 223 babies Turkish Baths in Your Own Home...... 237 A Convenient Holder for ra ee Fiote Ss. 250.0253 280 A Stimulating Climate pote the Cause of Suicide 280 A Tooth-Brush Drill for School Children ....... 325 Teaching Health Lessons with Automobiles and eS Sn iene napa eee tae 344 Digest Your Food Electrically! You Can Do It with a Wireless Apparatus.................. 5 saepine the Deaf to Hear with a New Electrical pe Our Invisible Friends and Foes................ 366 Grafting with Frog’s Skin .................50-- 382 ne —_ of ay Hig ds ORY Pee 395 Special mpoo Chair and Basin............ 400 Curing the Insane with Water................- 401 Portable Moving Platforms ..............2.00-: 405 A Stretcher Which Parts in in bet oe Gey ore a uring Rheumatism with Radium.............. Supporting the Arch of the Foot with an Extra Heel 429 meumatic Tires for Your Shoes................ 36 A Tooth-Brush with a Removable Bristle-Pad.... 456 Breathing by Machinery...................-:- 528 iiehtins a T hoid. g ieeT We go hebew a o's 531 icycle to the Rescue in reatments. 576 Bathing in Melted Wax..............2-0.00005 . 578 “ahrmag Music as an Adjunct to the Operating sa5 a the ahaa a Clean Sweep with a Rotary Se aoe: Cee ee eee 7 Page ” Massaging the Digestive Organs by Deep Breathing 664 A Toy Field Hospital for an Object Lesson. ...... 673 Testing the ration of Wooden Feet and Legs. 681 A Gentle but Firm Restrainer for the Insane..... 726 Getting Rid of Vermin in the Trenches.......... 742 esac = 2 Waiters and Cooks Must Mani- ree Fruit Acid, a Good Mouth Cleanser............. 828 Ultra-Violet Rays for Bald Heads............... 880 Rubber—An Armor Against Disease Germs...... 894 A New First Aid to the Fractured.:............. 916 MOTOR VEHICLES AND THEIR ACCESSORIES Fe emnoe TRUORUOGES oo cree sce cc ces sc kes 3 No Danger of Falling from This Motorcycle. .... oe The Motorcycle Becomes Popular for Sledding. . 50 tS aed a Motorcycle into a Motor Ice-Sled..... 50 a New Motorcycle Record............. 51 meothing Skating Surfaces with a Motorcycle Ice Combining the Garage with the Home......... 52-53 Picking Up Tacks in Front of Your Automobile... 72 Putting Railroad Wheels on Automobiles........ 82 Automobiles, Motor-Trucks and Accessories. . . .84-87 Py FeEEOE OOMBDOORS t555 ahaa s ce sess 5 cat Sst ee 106 Seper h sre MAOMOG hat tete vs dr access tne tees 107 A Wooden Boulevard Over the Desert........... 116 Climbing Out of a Mud Hole.................. 118 M the Automobile Do the Chores......... 119 Paper Funnel for Use in Place of a Grease-Gun.. 122 —— Luggage-Carrier for the Running a A t iconne, Ten Holder for the Front Axle of an RNS ee ae ea bob oe a ~ ss ss s'ae es 126 Repairing the Torque-Rod Support of an Auto- EIS nS ee ees ea eee vee wie ao ans osicaee 128 to Build Bucket Seats for Automobiles. .... 142 hy the Tread on Repaired Tires Fails to Stick.. 143 Sheree Steam for — in Automobiles. eee pmeatatre Road-Oiling Tank ............... Road-Rail and Its New te EOE so akin cokers 192 Ravert Your Bicycle into a Motorcycle ........ 195 New aye Motorcycle Uses Two-Cycle Motor with a Se PISMO Tuo. oo eek Chet cee 200 A Hot Plate Camp Stove for the Automobile sper 206 To Unload This Truck You Tilt the Platform... 208 You Can See — ei ER REOMS 5 cle cick os ce « 216 Standardizing Our Automobile Shop Language... 230 An Armored Motor-Car for the Navy........... 231 Low-Bed Truck Steered by Huge Wheel... Removable Steering-Wheel to Fol the Thief. .... 251 Automobiles, Motor-Trucks and Accessories. Bringing the Steering Wheel Back into Position PRRNRRO MEU ree Sas «are t's wa wa « U:.5.0-s'5 was 258 A Grocery Store on Wheels. ...............2-0-- 267 Motorcycle Lamp and Horn Combined......... 270 ning Automobile Doors by a Foot Lever..... 272 An Oil Made from a Broomstick.......... 283 What Do Your Tires Cost You a Mile?......... 284 Removing Automobile Engine-Valves Enclosed in a UE ed ee ce d/o weed ewceccccc: we 10 A Motor-Manikin Which Waves Its Armsand Yells 344 Teaching Health Lessons with Automobiles and SP EEEMSOR od Chieweres stn i cccescas aries 344 Hoisted by an Automobile Into the Clouds....... 352 A Pushmobile De Luxe for the Youthful Speedster 356 Making the Front Axle Help Drive the Automobile 357 The Workingman’s Automobile................ 357 A New Bet Dateceatal for Automobiles........ 360 Combined Brake and Non-Skid Device for Auto- MMR EMDR Ma Taal owes cbs ec ehces 362 Light Railroading Accomplished by Automobile... 362 Another Addition to the Sy ay ame yee Family.. wets A New Type Motor-Truck for Coal De = aba oka s 3 Automobiles, Motor-Trucks and Accessories. . . .364—65 The Automatic Traffic Controller............... 382 — o Drive an Automobile............... 385 odel 60 CRS MROTEMO Cie beeccceneueceeess 386 aE AGCKEED VUNCMNIEOT Cosas ceed caeceteccctccece 391 Sacrificing Diamonds for Accuracy in Manufactur- I Vines cewcicacs ees sone cnese.s tiers ed an Automobile Steering Wheel with “a A = a condi for the Automobile............ 416 An Automobile Salesroom on Wheels........... 422 New Motorcycle with Horizontal Opposed Motor. 427 Page Whee. Boos Pavements Cost the Automobile Cleaning "elec UiE Bann daten buen haceeals EIN gig uh ko ahSede gic Wasa HIRD ve 9 Removing a Heavy Truck- Wheel Without a Chain- Uideg Dirty Werte Oil irom Agteassinia Ceankeams 452 An Improvised Trouble Light for Motorists...... 458 Portable Stove for Campers and Automobilists... 469 An Exhaust Pipe Heater for a Motorcycle Sidecar 466 Right peers for Bead Molds in Making Tire asi eye Tank Condenses Boiled-Over Radiator Sand ‘50g ocd If It’s Slipper The Newest Auto- mobile Accessory Does at Stee eee A 5 Automobiles, Motor-Trucks and Accessoies. ..514-—515 Shifting Gears Automatically .65 scst ene cs wane 524 New York Police Uses Wireless. ...........+--+ 531 Asmored: Motor Gars.....si0hs ahinisiv abo as as heen 540 A Vacuum Automobile Brake................4% 54 Cleaning Sewers with the Aid of a Motor Truck.. 556 Increasing the Push of Automobile Engines...... 560 The Gasoline Caddy and Errand Boy........... 566 Look Out for Automobile Gas—lIt Is Fatal. ..... 568 Reqylating the Automobile Searchlight by a Simple REO 32s grea aa ion! 0 nC ae ae Ie 569 Grind Your Valves at Home. A Machine Made for Car Owners: 4.465 conc pe eee A oe Sains 576 An Alarm That Warns You of a Leaking Tire... 580 At Last! An Automatic Motor-Driven Tire Pump 586 Automobile Lights Which Turn with the Roads.. 588 Removing Carbon from Your Automobile Engine WOREEL WRUEES 0 sc Sane e rest + aleceetan ee nen 8 Hitching a Motorcycle to a Buggy............- Converting an Automobile Vater a <4 a Workhorse 598 Dynamo Eighting System for a Motorcycle...... 601 Things to Know About Motorcycle Clutches .... 601 Marking Date of Repairs on Automobile Tires. 604 Re-Shellacking a Cork-Float on an Automobile TPR a sine Ks sale tis Ske eats Deas AGS eS 604 Housing the Motorcycle. ...........00e ees eeeee 605 Marking an Automobile for Positive Identification Nye: To Keep Weight of Automobile from Tires...... A Lubricator for Automobile Steering Pivots..... 61 t Replacing Old Valve-Stems in Automobile Tires.. 614 Using the Automobile Jack to Straighten a Frame 619 A smply Constructed Vapor Plug sn Automobile INOS. 5 cig Noa pulp a Sd aE CRE A Kes ae 626 Don’ € on Your, Gar Plogr. sina sake ce Sasale termed 645 An Electric Signal System for the Automobile.... 684 Automobiles, Motor-Trucks and Accessories. . .686—687 The Army Mule Ambulance. .............00005 703 The Circus Motors to Town. ...........002+0:- 709 fa Comaoling EhOree | ois 0s. eaves, aidacin anual 710 Ba@icient truck Loade®..... 5 ss.ss0te cic cs eseaus 711 Rew ANBAS OF te LENKS oss o pok ge cae Kaede sa oo 712 Automobile Contest Winner............---.05: 720 Wire-Mesh Top for the Automobile.......... 727 A Non-Skid Automobile Device Without Chains... 729 An Electric Semaphore Signal for the Automobile. 735 An Automobile Spring which Takes up Shocks. 750 New Valveless FourCyele Gasoline Motor. ..... 752 Using Straight Side Tires on Clincher Rims....... 761 A Small Single Cylinder Homemade Automobile. . 762 Repairing a Broken Carbureter Lever on Automo- SS SNR 08s Pe i nin otk aa ce ho assed Gace 769 Remodeling the Motorcycle.............0:200: 771 Starting Automobile with Current Taken From MTORR 6.5 voc 8354 bn a a 0 ef AE ach Sea Cee To Cut Automobile Tire Fabric on an Angle...... 780 To Prevent a Motorcycle Theft by Short-Circuit. SSM REMNIS «5 5 cuigailinn’ so '5'6s Couis 6 tins aeons 786 Another Inventor’s Idea for Speeding Up the M5 ssi pL Shas eae a edie inus 805 An Observation-Tower Car for the Army....... 837 Automobiles, Motor-Trucks and Accessories. . .838-839 Barney Oldfield’s Racer.............0.cceeeecs 859 A Good Automobile Whistle................... 866 Ploughing the Farm by Automobile............. 881 A Combined Automobile Spring and Shock Ab- eg 2 o.9.p n'a -tn. 00 <= 5 sk a moine guns Carrying the Cook-Stove on the Automobile Trip 896 The Double Automobile Spring................. 914 Troubles with the Safety Spark Gap on Motor- ae eI O SS via ode ih ta si0 co «si ae Saw A he 922 Substitute for an Automobile Hub-Cap.......... 934 A Telescoping Motorcycle Jack for Road Use..... 936 NATURAL SCIENCE Page Not Buried—Only Encrusted in Snow.......... 7 The Great Hawaiian Volcano Kilauea.......... 10-11 Are There Inventors Among the Insects?........ 20 Eyes That Were Never Made for Seeing........ 21 The oer of Ice Crystals............-- How Do Birds Always Know Where They Are?. How Do Fish Locate Fresh-Water So Unerringly? § How Life Begins. css: = 3005 55 Sen eee 88 An Icicle Which “Sprouted” Overnight......... 92 What Jack Frost Did with a Fountain of Running Water sic. c.0's & » 0.4nw se Geico bie sk eee g A Winter Experiment with Bulbs.............. A Tree Root that Resembles a Rie Deer. oiainy 165 A Wonderful Specimen of a Petrified ird’s Nest. . 188 Music from the Bowels of the Earth? Yes; in Texas | This River Is One of Nature’s Puzzles ........... e Don’t Eat This Unfashionable Fish ........ 305 Snow: A Curse anda Hieising., ee tale pie ee Wes 225 Even Bees Should Be Careful Where They oy 243 re You Interested in Cellar Farming? Let the Parasol Ant Instruct You... ....cseceecessos 243 They Grow Cannon Balls on Trees in South America . oii 408 i nein ce be See eee ¥ 4: Mk, The Native Homes of Orchids and Dwarfed Pines 336 Blonde and Brunette Bears of One Species...... 341 Meking Artificial Leaves........... Bay hcg 2 HS 342 Horse-Collar Grows on a Tree.........-.++..- vi 343 ‘Prensplanting Palin Treea Without Sacrificing Their Foliage. 6665553 23 3 $9 bee ee 1 The Transformation of a Caterpillar’s Foot...... 428 The Strangling Fig—A Terror of the Megetahis Kingdom, . 2... 'S otis pidan> cuss be eee A Seacteracil as Compared with a Railway Train. . & T S a ‘ Sentinel Rocks and Their Story.............-+++ Nature Supplies Boise with Hot Water.......... How Did the Crocus deh in the Bottle?....... a5 Do You Know That We Americans Have Over a Hundred Volcanoes? ..:......-cecceentaceces 587 Teliing the Age of Water-Marks on a Lake Shore. . 595 ature Hides a One Thousand-Pound Stone Toma- awk in a Coal Mine............+++-+s00+> 597 The “Missing Link’’ Amey the Fishes: ........ 672 That Cloud—How Fast Is It Drifting?.......... 674 Why the Tendrils of a Plant Grow in Two Direc- HONS... > cas 0c okle bie a 0 5 Aiealeoce ee ae 677 Mystery of Stone Giants. ....... 20... -2eeeeeee , Siamese Twins Among Trees..........--++e000+ 71 A Miniature Grove on a Tower...........-.--- 28 Relics of the Almost Extinct American Buffalo... 747 Like a Combination Tool Is the Blood-Sucking Apparatus of the Horsefly...............++- A Self-Warming River.............4+- av kbemae 751 The Birth of a: Butterfly 2. 00.035. nes. toe 824 The Mangrove Shields a the Savages........... 33 The Gourd in the Battle. 00.2.5 4 oe scaansi nen 3 Natural Curiosities Among the Rivers........... A Flowery Conception of the Western Hemisphere 897 a a Which Fly a Thousand Miles Out at PHOTOGRAPHY AND MOTION-PICTURES Giving Body Relief to Motion-Pictures..:...... 28 Photographing a Bald Eagle..............-+++: Fs esting Your Camera Lens. . eg cette neeeageres 8 How Life Begins. os7s'. ssn ole snl 6 v0 gee 88 Producing Trick Photographs. ..........+++++:: 104 How Motion-Picture Statues Are Made Overnight 114 Avoiding Eye-Strain in Watching Motion-Pictures i Making Storms to Order for Motion-Pictures .... 115 Wh eels Run Backwards on the Motion- is ot | IETS Py me eee The Making of Photographic Silhouettes......-. 127 Making a Niotsou-Pretare AMA ...> tess SS SE NE Eo Eg ee Pee 134 A Writing Ink Made from Discarded Typewriter ea Sides & Maneatis Gkenath occ. 2coe BS An Adinstalle High and Low Stool for the Type- es nee Wiius Hames Cd Varniol oc Poot. 137 Siding Exhbe Tiny for a Show-Case Top. 137 Making a Small Gas pe jrass ng. Sawing Boards on the Table of a Ma chine 138 A False Ceiling © of Lattice Work for Ornamental Ue PE ee eae > ae 138 ye ES SE pe | eee eee 139 A Shoe-Scraper Made of a Wagon Step......... 140 How to ‘Make § Spiral Springs with Breast Drill . 141 ple M aden cay ed es sgt st rerware vis The Tea-Table Ides Arplied te the Riches i4l Discarded Range Boilers for Air Pressure anks A Cork Substitute for the Toilet Flush-Box Ball.. 142 How to Build Bucket Seats for Automobiles. . . . . 142 Pho phic Focusing Table for Hand-Cameras.. 143 An ae Hunt for Readers of Current Maga- Solution ale Cl en RPS ee ee ee 143 Why the Tread on ing. paired Tires Fails to Stick.. 143 Fastening Brad-Awl Blades Securely in Handles... 144 Preventing Melting Frost from Dripping on "SE eR ep ee eee 144 ToS a Reed fer a Clarinet or Saxaphone.. 144 Giang ther, Cloth, and the Like to Metal CL SES Se ok Sa eee ee 145 Making a Bin for Storing Scrap-Brass Collected from SUE PEs Ss EL ule.o < o's ste ac 145 wing Frozen Water-Pipes with an Electric eS eT a SSS ea eee ee 145 Coloring Electric Globes for Decorative Lighting.. 146 Estimating the Cost of Painting a Detached House 7 A Knitting N. Used for Testing Milk... .. .- 46 Py 204 poder Disappear at a Word of Command 281! A Gas p Riddle for a Store Window Display.. 282 Cleaning Steel Pens with a Glycerine aesee Beek 282 Brass and Copper Tubing Easily... .... 282 A Cigarette Holder Which Expels en nad End 282 House Plants and How to Care for Them........ 284 Heating a Rusty Nail to Loosen It for Pulling. 285 — to Make an Adjustable Drawing - Board Face Vasette Made of Copper Plate and Test-Tube.. 286 Avoiding the Dust from Ashes in an Old Furnace... 285 Wa EER AIS 6806 oS a Oe ea We Neate RON ee 287 A Bolt Washer Used for a Nut Lock............ 290 Making a Kick-Mobile for Snow and Ice........ 290 A Craftsman’s Combination Foot-Lathe......... 291 Hand-Brake for a Flexible Runner Sled....... 294 Testing the Quality of Leather Belts with Vinegar 297 The Law of Retribution in the Insect World..... 297 A Comfortable Collar for the Horse............ 300 Making an Ejector of Pipe and Fittings......... 301 A Sharpening Block for Keen Edges on vere 301 How to Drill Holes in Glass with a File Point.... 301 A Tool Post Chip Guard for a Lathe........... 301 Small Auxiliary Oven for a Gas Range.......... 301 An Old Steam-Boiler Used as a Coal-Bin........ 302 How to Protect Mounted Curiosities from Dust., 302 Crumb Tray Quickly Made from a Candy Box... 302 Fire-Escape Window Bracket with Naat Se Basket 302 Building a Farm Forge and Blacksmith S 03 Poe 5 pa that Desauecs a Bench and a ihe aa ANB op to ais Imitation Marble with Paints..... 304 apmovine the Cones from Ball Bearings on Mag- sai oS a a Light er to the Kitchen Walls....... 305 ow to Make a Support for an Automobile Frame 305 A Portable and Adidetable Holder for Storing Rtctames ROCK Gs, Gesis os sl Sale ea CU ee 306 Turning Small Screws in Different Places with a GOG Screwdrivers fac s sodas 6 cx aes 306 Finishing Aluminum Surfaces on a Buzz-Planer.. 306 To Repair Nail-Hole Punctures in Rubber Tires. 306 A Showshoe Fastener Better Than Strings ...... 305 An Electric Gas Lighter for the Kitchen Range... 314 Detecting Defects in Castings with Magnets..... 318 he “Tungar’’ Rectifier for Charging Batteries on Altornuting- Current «q., i. Sie ossescccaees os 16 A Pliable Metal Screen Fabric as a Substitute for MAMIE heather te vacks os arene! glgeh er <'e eho atety' oor am biaiane 441 Carrying Two Large Cans of Water Easily...... 442 The Protection xe Care of Shop Belts.......... 442 Pulverizing the Powder in Fire Extinguisher Tubes 443 Foot-Power Jig-Saw Made from a Sewing Machine 446 Construction of Mechanical Crystal Chimes . . 4 Handily Se say 2 Case for eres Tools 5 oe Inks : A Mixture for Removing Paint from Woo To Make a Triangle Gage fora Cross-Section Liner Making. a Mahogany Case for a Clock....... 50 A Perfect Five-Pointed Star Drawn witha Compass 451 ay tere a Heavy Truck-Wheel Without a Chain- cae An Adjustable Shingling mcr for Sfeping Fs Roofs. . 452 Keeping the Tobacco at the Top of the Can..... 52 A Concrete Letter Box in the Form of a Posi. 455 Locating Electric Conduits in Old Walls......... 455 An Easy Way to Cut a Circle from a Glass Plate.. 456 A Method of Mending a Leak arden Hose.... 456 A Novel Lathe Tool Oiler Made of a Varnish Can. 456 A Safety Envelope That Affords Real Protection.. 458 An Effective Garden Path of Brick and Concrete ESS aes ace a SA ER Te Paneer om 459 A Stopper for Poison Bottles.................. 459 Bracing the Back of a Long File for Level Work.. 460 Holding Reference Drawings on a Drawing Board OW PMMOTAEE Sor, eS a). eG Mews Oa e we SOT 460 How to Plot Angles Accurately................. 460 A Home-Made sDitdese Cooker for the Camp..... 461 To i a T-Square from Slipping on a Drawing ae) A Filing Clamp for Use in the Jaws of a Vise..... 2 A Brad Awl Made from a Button Hook......... 463 An Emergency Mallet Made from a ee 463 Making a Tap and Die for Emergency Work..... . 463 Waste Scrap Leather "Jsed for S Shoe Shes 30s Sal 463 Holding a Nut Steady Without the Aid of a Locknut 464 Making Wall Plaques in Plaster of Paris......... 464 Making Parallel Bars for the Home Gymnasium.. 465 Making a Practical Fluoroscope at Home....... 472 Cutting Holes in Plaster for Switch-Boxes....... 473 pe Gh AS ELS | SE Sh a ae 604 An Emergency Clothes Hanger Made from Paper. 607 A New Combination Triangle for Draftsmen..... 07 Cleaning the Crusted Carbide on Containers..... 608 A Novel Waste-Basket with a Drop Bottom..... 608 An Accident Chart Showing Injuries to Miners... 609 A Rabbit Trap Made of Ordinary Drain Tile..... 609 A Wall Book Shelf of ‘Built-in’? Appearance..... 609 Goggles Used in Chemistry........-....s000005 610 Page eres oS with a Stick Used for Paper File..... 610 Keep Weight of Automobile from Tires. a weiea Ce Ke Adjustable Stand Helper..:............... 611 A Free End Hacksaw Blade for Difficult Work... 611 A Lubricator for Automobile Steering Pivots..... A Soda Mixture for fa Booed Removing Mah How to Construct a Door-Mat of Wood Slats. An Expanding Bale i a Bottle Seocae pa Ear ee Moving Targets for a Home Spee Gallery.... otor Boat or Motor "Chee oS oy Making a Reamer from an Old Three Cornered File A One-Piece Hanger for a Flaring Pie Tin A Quick i Pie io Level th 1 the Legs of a Table..... es Replacing Old Valve-Stems in Automobile Tires. . A Successful Anti-Leak Device for Paint Brushes. Plans for Smoke Houses............2+0ceceeeee Shoring Up a Porch-Post to Repair Floor-Boards. Pan for Sterilizing Dairy Utensils ............. A Pract Gasoline fo with Oiied. aa Piidetakee ca Ti ractical A tt tt tt nt ct ed DBONIAUALALDAWWWNNNN—— ee er rd - jag ae So ree ae 324 escuing a oh bg tage es nese cet panes aze ccomplis y Automobile. Ligne Ra Ride ay pg Ch ate ale natn ialh gs cna wi © 384 Meat Packing with the Aid of an Electric Railway 414 Building a Street Car Line Without-Stopping Work | 0 8 See? gee ee ea Moving a Railway Car by BME e at oe ook hans 333 Alaska’s ““Pupmobile” Sener el DS ERS 584 Safeguarding Open Drawbridges..............- 599 Railroading in Alaska Is Still Far ieee Rapid.. 664 Clearing the Tracks of a Crippled Car.......... - 678 A Portable Electric Welding Apparatus......... 734 Locomotive Coal Machinery ................--- 910 Dispatchi cae on One-Track Lines........... 918 Shower Ba ES Culm ol nia bEAp oa 60: so .0-*s 919 SHIPS AND SHIP BUILDING The End of One of Farragut’s Old Flagships..... 13 The Superd en Pennsylvania........... 17 Building a Ship Like Caesar’s................-. 74 Rich teat ies of Florida Rivers ............- 219 The Biggest Battle Cruiser.............-.-..-- 268 oating Safes for Ocean Liners................ 323 A Garse of Dried Codfish Sunk a Schooner...... 349 A Round Trip to the North Pole in Ten Days... 434 The Life-Preserver Chair Cushion............-- 486 The Wreck of the Sumner..............000008: 497 ‘Thm error of the Seasisad sac chains cs oes veh 546 Trolley Care on Water. 5.0.6. cbc eb eed cere 560 The Acetylene Life Buoy. It Blows Itself Up 583 orpedo-Boat Destroyers. ............00ee eee 693 A Non-Sinkable Lifeboat. ............600ee eee 696 Hiding a: Ship. in Smokes). 5: 066 be Sis, be 704 Fighting Crafts Cost a Fortune to Build......... 725 at’s a Dreadnought? nd Its Purpose?...... 729 The Battle Cruiser of the Future............... 730 The Torpedo Boat Destroyer................-. 826 Six Acres of Coal Floating on the Mississippi.... 836 A: Siant Lafe-KRaft |. o.isord aerials ck pub dives 850 Wooden Ships of 3,000 Tons..... whgkgsSchbasads- Py ial eet 860 A Sunken Ship That Earned a Fortune.. ........ 884 Freighting a Steamer by the Marine Elevator.... 908 Locating a Sunken Ship.................20008- 920 SPORTS AND PASTIMES Prince, the Only Ice-Skating Bear.............. 4! Riding a Bicycle on Your Stomach............. 41 Salmon Fishing in the Columbia............... 99 AP Coasting: Bob 2.0406 0.05 Ae eee en ees 139 An Electric Alarm Signal for the Fisherman..... 149 The “Why” of a Golf Ball’s Flight..... . psneiie 186 Is This the Secret of Ventriloquy?.............. 209 Bicycling for the) Blind .0)..24006..0.. sick an fk Her 207 a. uch ag - eae 208 PAOMOE SOP RIAER os ce Se pbc ona o's by pen Hee Show Case and Scales............. 212 ne Tt @ Poros... <<... vows susnsccbus 218 MMMM CRD oso oaks wes cS es ble Ce aes as Don’t Throw a Horse. Make Him Lie Down..... 230 The Rubber Stamp Has Many Uses, Good and oes 231 Even Horses Must Have Drinking Cups .. eo The Ferris ena Baby Contant 239 The Eskinso Wockbacker le Worn Abort the Meck. Are You ° Srescllge o Then Sit baud od —_ one a i 240 Keeping u ts t A Caliper tha ry Sy irae Extraordinary Measusimere 244 W: Rives Water for Power Plants......... _ 245 ON RL MOWwR SOW <5 iba oss «0s The Most Nutriment in the Least Space........ 251 Help Protect Yourself......................-- 260 A Diving ——. — from a Boiler........... 262 ao “Mouchoir * — So MEAD TES ee ee California Nove’ ee in Street Signs. ........... An ator Sewer-Cleaner. .............00050. 267 Shoot with ate es te a Spetge ea 272 Will We Dress in Paper Clothes? .............. 273 How Much Does that Cloth Cost?.............. 276 You Pass This Examination?............ 277 swe and Your Shoe- Will Never Be tied 304 Chin Chin, the Elephant, Gets Her Winter Shoes.. 326 Applied Mechanics in the Secret Service......... 346 Conductings Than ie Sanitary and NViocuntal Boas 368 ucting a Thriving Business t Ab Ocean of Geeon Sik. Races * 372 Making a Fortune Out of Tears................ 373 Hell Swazey Breaks Up the Dance ............. 376 A peecies omedian for the Piano ........... 383 The Mothering Instinct in Hens............... 383 Where Cows Wear Spectacles.................. 8 Why Does the poet a Beating at Death?..... 384 A Land Ride for Whales...................... 84 Old Dobbin saied Fee oe ee re 89 An Ant Can Carry Ten Times Its Own Weight... 392 TERMMETMAD Ae SUS 5 Ciois cits ctlad oo Seek kins . 392 A Cane with a Flashlight. _.................... 393 goer of His Clothes by a Projecting Cutter... 396 ham ampoo Chair and Basin............ t the “Kick’’ Out of a Revolver .......... 5 t a Does a Rifle Bullet Return to ne Blind - es ER CORTE Ae pepe SiS Nae eae 417 yen Saterty Boll Is Sick and That Is Why It RS Seer eee a eee ane eae 420 Making It Possible for the Horse to Eat Com- rapa © NES tsa os ses wVisiioe ne te sk tleeaee 2 a New Use for the Back of a Chair...... 423 A Safety Box for Carrying Blasti Caps...... 426 - Snake-Bite Proof Material for Soldiers’ gings 429 Tobacco-Pouch and Purse Holder Combined... 429 a You a Good or Poor Penman?.............. 430 A Pocket Revolver No Bigger Thana Watch.... 431 Strap — Purse to Your Thumb. No One Can Steal Oe vainantre ss ek caicaees SU ss 437 [migating an ete Resbtati le es occ cdc cv wd tle ae 440 the Hawaiian Pineapple Industry. 505 Page Eye-Glasses for Divers and Mermaids.......... 506 aking Buttons, Bric-a-Brac and Seng from Milk.. 507 If Your Fur Coat Is Dingy Steam It............ 510 Handprints in ST gritty SAP a & Ree 516 DOS Eg ee a ea 517 Meer amigeg Wild Aainok to Stock the Parks .. 517 House to Protect a ot 525 a Elevator Guard....+...... naga Sea oS oc 525 A Hoopital Clock Sear ene a bet ee ees cal Fe 529 AP remem @ cmist Of Water. 2... 6.65 ee ec. se 529 Ape wectical Pile Protector... 0.505650 feces 538 Selling Hose Meat in New York. .............. 539 uN MRMEMMEEMMR ISS re ke clo soma Se 6 wis es 6 563 The Two-in-One Watering Trough............. 563 Making Clothing from Nettle Fiber ............. 565 Was This Inspired by Prohibitionists?.. ..... 565 A Kentucky Woman Rises to Great Heights 567 Did You Ever See a Million Dollars in Gold? ...... 568 SPU EWG SCRttIOle ... . 2 Se eee Sl ce 574 Defending the Home with a Mousetrap Gun ..... 577 Spinning a Top by Means of.a Spring............ 577 y Does Oil Poured on the Waters Calm the Sea? 579 Moses Didn’t Want to Be Shod ................ 5 Marks of Age in Dressed Poultry..............-. 582 Saved by a Tin Filled with Soup Cubes.......... 582 erg al ae etol dnte a Mme... es ck se 585 A New Safety Pocket-Book.................... 586 Using Waste Tanbark in Making Coarse Paper.. 595 Fires Which ——— Themselves.......... 597 An Alarm Clock for Awakening the aaa Ay eee 602 A Small Filter for Light Machine Oils. pes | s, Getting Rid of White Ants .................... 603 ee ee ree 644 A Stencil-Cutter and Typewriter............... 673 ae Is a Man? Break a Thousand Eggs and You'll Have His Contents.........2:....... 676 A Switchboard rator Finds Time to Embroider 677 Corrugated W: Block for Street Paving. ...... 678 RES PUCOMEMEN SG Maio bk cscs oc Coosa sks 681 Je OSS So SE eee ree 682 Pumping Air to a Diver Son a a Bicycle Pump 685 Foolproofing the Automatic Pisto! 688 wee Arizona, Finds a New Une for the “Water ine i Se een ae eee Pe A Tiedbone 3 in Eraser pegg bak umeehc eo o Cx. s: fel nce yi kai 693 Long-Han PRM clit @2 lean's.< kb oso ack 703 Fire Esca Chutes Se ROTO cos os et5 0x csc 711 Women wash London Curbs.............- 717 The Wonderful Watch in Your Pocket.......... 721 _— a ie from a Burning Building with His “ae Blasting or CPA da SO Uaioe ssc ge SN Sharing Your a with Distant Friends. .... 731 Safety xr as Applied to = Hammerless Gun.. 732 A Steel Body oar Arms and Legs for = Diver. . 732 Stock Power Sand Screens for Small Combining the Sword and Pistol in One Weapon. 742 resh Air in a Manhole Through a Mask........ 746 This Machine Tells You How Much tn Eat. o3% 747 PC Omega DatKOk cs Se ce ces _. 748 Two Hats with but a Single Crown.............. 749 New Uses for the Rubber Sponge.............. 752 Blow Up the Earth? Not with Eee pee Ge ws 754 A House Made of Fire Relics.................- 760 Beach Patrol of the Coast Guard............... 807 Catching Flies by the Barrelful................. 828 Bee eee Oe ree = nk as cs a ee cs ee se 829 ie Sr gs aaa ape eo er ee rere 830 iPS RUMMERORMEDED ©). ly 2c elk c'c.co's es bt os we 849 A Glass Lighter MMA CONE esis oe ses oe 856 A a for a ““No Spitting”’ Placard......... 858 Perching the Fe peg aay DORR ew ag ace wae eS 859 Newspapers Wipe Out Forests.................. 859 Some Lessons from Deep-Sea Divers............ 864 A Seay ws So ees eee 865 Ser! bees SS OR eS 866 Deaf Mutes Cale PONS LG aso Saws oc ess 870 Attaching the Phonograph to the Telephone ..... 871 Moving a ——* Switchboard Without Inter- OOS ee ee ere What ay Gallon of Cissolines rf. Le OT aS 888 Why Do Rifle and Shotgun Barrels teem SARS 889 Three Separate Plans for Making a Gun Think.. 890 The Money That Goes Up the ag Lj eer tae 898 dling in the Newest Way Without ee Aid © ee ee a eee eee es Are Filled... 311 t Ladder... 914 Turn on the Faucet and the Sau Saving a Drowning Person with a ie: ; = z 9 . 4, Big € fitistmas: Present For may $1.50 ate This 5 year give your ese a real present, ~~ one they. will enjoy through the whole: year. ; Give the Popular Sciefice Monthly for 1917. g _ A year’s “sabscription—twelve issues—costs | _» only $1.50. The twelve numbers will contain Ses ; Hee “Ss > - < = _— = aa et : over 4,000 pictures z a gt over 2,000 articles : re. over 1,800 pages . : == SEF eS. a2 = <0 oes 3 ahd will tell the whole Seonderfal sory of the = o* ix eh years progress in invention, mechanics, and ; #*. science. : A Pacis Gift Card will be sent to each friend =. announcing your gift. The first copy of the maga- *. zine and the Gift Card will be received just before Christmas. . Re ae a. ee ae - Sulsscctmiienn $i. 50. ‘Canadian postage 50c extra. Foreign $1.00 extra. Popular Scidiite Monthly Gift Club. % sees 239 Fourth Ave. New York, N. Y. They. Used to Shoot Sick Dogs--Now They Cur ~.cm | i i The machine which Dr. Little employs in the animal hospital in New York city for admin- istering anesthetics to animals. It consists of two cylinders, one containing nitrous oxide and the other oxygen. These discharge into two bags each of which is connected with the mouthpiece attached to the patient’s nose. The flow of gases is controlled by valves 2 . ee ae rag] r 1 ~ Popular Gience Monthly 7 239 Fourth Avenue, New York City Vol. : 90 - | $1.50 "Nov 2 January, 1917 Annually Don’t Shoot the ‘Dog—Help Hint: as = turned on. Ina short-time the animal loses eae? if He Were Human ~ consciousness. It is then given a little ]F some cats and dogs were hot decnak ie oxygen to sustain its heart action. With i would undoubtedly get up a testimonial: . the use of oxygen which the surgeon ad- to Dr. George W. Little to express their ™unisters at his discretion, the patient may 2 gratitude to him for introducing a substitute remain under the anesthetic for hours: : a for ether—a substitute which enables them — During the operation the animal feels . to withstand operations that.are particu- 0 pain whatever. When it comes out of : larly hazardous when performed 4inder ether. the unconscious state it is able to walk to Although because of lack of ‘ifmagination its ward in the hospital and apparently feels animals “do not suffer mentally~as do 20 ill effects at all.. The new anesthetic has ~ humans When facing an operation, it is beén particularly successful when given to impossible. “to “perform a serious operation old dogs which suffer from tumors. W ith the : — ut aid= -of~a_ local - anesthetic. Dr, use of ether for such a serious operation an -e,:set“about ‘to find some — aged dog has very little chance for recovery. ch. would. -render the opera- - tiene palsies: ‘to the animal, would not ie its heart action and would not cause. ~ Convertingza Discarded Toy into= ae = Se a Real Automobile it rom shock-“*He has succeeded™ * 2 by adapting ‘to his. _uses the gas anesthetic HAT all the ingenuity in the automo- ¥ used by"¢ dental surgeons. ig bile line is not confined to the workers eS The “machine which Dr. Little employs - inthe big factories, where the various in his) work in-the Animal Hospital in New makes of big cars are produced, is evidenced York ‘city, conducted by the American _ by this. picture. This boy,#down i in Texas, Society - for the Prevention of Cruelty to where the prevailing ambition is to own a Animals, consists of two cylinders, one farm so it can be mortgaged for an auto- containing. nitrous oxide and the other mobile, had the auto-bug himself. The oxygen. «The cylinders are con- farm and mortgage seemed too nected with two bags by remote for his earnest longing, tubes... One bag is filled so he made his own car. with the gas, the other Taking an old, battered with the oxygen. The toy automobile that some , outlet of each bag | child of wealth had dis- carded, he attached passes into one tube connected with the thereto the little mo- tor from a_ bicycle. mouthpiece that is | attached to the pa- The hood he impro- tient’s nose. .The vised from part of proportions of —the an old wash-boiler. gas employed may The steering ap- _ be regulated by paratus. he made ~- means of valves. ; himself. When the The dog or cat in machine was_com- need of an operation plete it made the _ is placed on the oper- trip to town, a dis- ating table and the tance of several miles in fairly good time for its size. It is mouthpiece adjusted over its nose. The A child’s toy automobile, a part of an old ; s ; wash-boiler .and a small motor are the P ee . nitrous oxide gas 1s component parts of this little machine still giving service. 3 Putting the Sun at Work in the House All that is necessary is to expose the pipes so that the genial rays can reach'them. There is no charge for service HOT WATER AIRTIGHT — STORAGE BOILER BOX “ HOT WATER SUPPLY PIPE * CIRCULATING PIPE wil gola or above a window. HE people of Southern California are letting the sun provide the warmth whereby the water they use is heated. The device by which it is done is known as the “‘solar heater.’’ It consists of a shallow box about four inches in depth, within which is a coil of galvanized water pipe. The box is covered with glass and is practically air-tight. A —~ The usual location for the heater is on the roof of the house; but it is sometimes over a driveway per- At right: The sun-coil coldest water from the storage-boiler. Dur-- ing warm, sunny weather the water that was first heated and sent to the storage- boiler will return to the sun-coil to be heated to a still higher temperature. This storage-boiler is encased within a wooden box and the space between the boiler and the sides of sheet of copper is placed behind and attached to the water pipes for the purpose of concentrating all of the sun-heat falling upon an area several times larger than that offered by the pipes themselves, thereby making the water correspondingly hotter. The pipes of this heater are arranged with a certain upward pitch so that the GALVANIZED SIT — RON , OR ROOFING TO IMITATE ~ CEMENT PLASTER wy / € FLASHING STORAGE BOILER the box is filled with a _ heat-retaining packing. The loss of heat by radia-- tion is very slight. Assum- ing that no water is drawn, the loss of heat due to radia- tion during the night will vary from four to ten degrees. Hence, hot water can be drawn in the early morning as well as at the close of a sunny day. heated water gradually } oem PEI Wag Ss bees | DRAIN ~~ From this tank the heated water passes to the various passes from the coil to the storage-boiler. As the hot water leaves the coil its place is taken by the fj cxemmo | VOrsTs The storage-boiler is encased in an insulated wooden box fixtures of the home. When the sun fails to shine a gas-heater is used. ag : — _ ; 23 - - = = = ea, * _— _ while the brushes for applying the paint followed on the rear — ¥ Popular Science Monthly 5 Painting Piping by Machine UT in California a one hundred- and-seventy- mile pipe-line was thor- oughly cleaned and painted without so much as a single dab from - oa “s : i wih te tis Celt MA hi i in ad! 1 ae _ he intends to market. _ He next rejects the en- _ except the one field he How I Judge Men By Harrington Emerson Tilustrated with Photographs Copyrighted by Harris and Ewing Mr. Emerson is a pioneer in efficiency engineering, an apostle of what has come to be known as “scientific management.”’ Long ago he came to the conclusion that although the best cost-accounting system had been installed in a factory, the best machines bought, the best arrangement of the machines devised, the best method of feeding raw material to the machines worked out, efficiency had not been truly attained unless the right man was given the right job. But how can you tell the right man when you see him? While Mr. Emerson does not attempt to answer the question fully in this article, which he prepared for us, he tells very clearly how humanity may be appraised by well-defined standards.—Editor. NY food is better than none. But if there is possibility of choice why not select the best which it is possible to obtain for health and purse? The difference be- tween the fine, large, perfect apples obtain- able everywhere now by the box or piece, and the rusty, shriveled, wormy and rotten ap- ples I used to find in the bushel basket is very great. I like good ap- ples, and not being in a starved condition take no other kind. How is a good apple created? By selection. The prospective ap- ple-grower rejects all stocks except the one tire surface of the globe thinks best suited for >ulidog type; __ his orchard, best suited as to climate, soil, exposure, so that the _ good stock will have best opportunity. _ noxious insects. The grower cultivates and fertilizes the soil. He favors useful and drives away During growth he may ruthlessly pinch off all undesirable buds, but in any case when the crop is gathered _he sorts and selects. If Cattle Are Carefully Selected, Why Not Men? How can we expect to secure anything Field Marshal von Hindenburg. Strongly motive; determined and inflexible; very practical, hard and intolerant; physical strength, power and endurance; a rugged, coarse-skinned man; stubborn; immovable 33 good, a good apple, a good bee, a good dog, a good cow, a good horse, a good man, or a good woman, except from good stock, de- veloped under favorable opportunity and care, and. strictly se- lected as to individuals? I do not expect it. Therefore I apply selec- tion. Before going any fur- ther it is to be noted that the family to which apples, pears, quinces, strawberries, blackber- ries, and hawthorns be- long is the rose family. All these roses are noble _and respond rapidly and greatly to opportunity and care. Unfortunately there are on earth genera as vile as the roses are noble. A Luther Bur- bank could not develop an- ignoble. rose, nor could a Mendel elevate great character lish, a bedbug. But there are living creatures in which the good or the bad is not so overwhelming- ly in evidence as in the rose or the cimex— species in which it is possible by successive selection to retain the good and breed out the bad. By following the laws of heredity, the thoroughbreds in domestic animals have been established. The racehorse man will enter an unfoaled thoroughbred colt in a future race and bet more money on him than he would dare risk on the most promising-looking and acting colt whose 34 LE IEEE Mental Type. CLL Quiet and reserved; tolerant; not ex- citable; close thinker; set, determined views; makes up his mind and draws his own conclusions; more ret- rospective than observant; slow and deliberate; syste- matic and self-centered Popular Mental-motive Type. Strong in self-esteem; ener- getic; positive and deter- mined; observant; convinc- ing; conservative; good talker; sure of himself and filled with importance of his own work; clear thinker; . practical and very energetic Science Monthly WYMY, Motive-mental Type. Plausible; agreeable and friendly; anxious to please; energetic and practical; sys- tematic; open-minded; pro- gressive; active and alert; observant; an accomplisher; - clear headed; good at out- pedigree is unknown. Principles of effi- ciency were applied to the evolution and development of racers long before they were applied to shopwork. Horses are not all good as the rose family is, nor all bad as the cimex is.. Each horse has in him a great multitude of special characteristics, and, what is quite as important, a lack of other strains, so we can at any time start with a horse in which there is a preponderance of desirable traits and of desirable negatives. Picking the Right Man Out of 1,600,000,000 Similarly, in selecting a human being for a position, our aim should be to find as nearly as we can in all the world the man or woman best suited for the position. Not only should the pcesition be well filled, but each worker should be in the highest posi- tion he is capable of filling. A Caruso, a Paderewski, a Kreisler, ought not to beg for pennies from door to door. In my own association of forty men I aim to apply the methods and tests that I recommend toall. I begin at the beginning. When any new work is to be undertaken the first question is this: Should it be done by a machine, an uncarnate thing, or by an incarnate being? It may be far better to assign the work to a windmill, or to a water- door work; great endurance wheel, or to some other power engine, than toa man. If, however, we need co-operat- Vv Count Zeppelin. Obviously scientific; an investigator; goes into matters with great exactness; has a good mathematical head; works matters out well; great perseverance, resourcefulness; new ideas that are well sys- tematized and worked out. A strong character ing, incarnate skill and intelligence, can the work be better done by human or by some other form of life? If I want to move four hundred pounds LAE Popular Science Monthly 35 ai gee CL OE OR Gin aa OE Pee Star es Be AE Motive Type. Positive; Motive-vital Type. Mental-motive Type. determined; opinionated; Coarse, positive tempera- Plausible ‘and full of plans; practical; set views and opin- ment; determined; dogged; likes to influence others; can ions; not easily influenced; stern and severe; impatient; irritable; not fond of society; reliable and inflexible; the rough diamond type of man endurance; Over a mountain trail twenty-five miles a day, it would be better for me to select a Admiral von Tirpitz. A great head for systematizing; a clear planner; arranges and plans beforehand; very little escapes him; good foresight; great will-power and determination; very immobile and hard face; not faltering; wonderful strength of purpose; enormous amount of endurance; hard to influence; thinks for himself; does not want to be told; very broad grasp of possibilities and conception of what is going on about him; has great faith in himself and his conclusions; great force in face—not a weak line; has an eye for the main chance; looks out for himself; not altruistic opinionated; not a great thinker; self-important; great strong willed; will put through his schemes in spite of great opposition conceal his real views and aims in clever talking; posi- tive and opinionated; observ- ant and calculating; plenty of self-esteem; clear-headed mule for the work. If I am going hunting, a suitable dog is better than a man. Immense losses have been suffered in the past because men were used when wind or water could have been more cheaply har- nessed, or men were used when horses and oxen could have done much. more. Our ancestors were almost as stupid as we still are. The value of selection between the suitable and the unsuitable was not obvious to them until fifty years ago. If, however, we have progressed to the point of wanting a man for a man’s job, the next question is how to select the right man out of the 1,600,000,000 human beings on earth. Unfortunate though it may be, many positions are subject to race restrictions, and this in the case of Pullman car posi- tions may cut out all but candidates of African descent, or as to many positions it limits our choice to members of the white race. If it is a government position the restriction is still further limited to Amer- ican-born or naturalized candidates. We have in this case already cut down our field of choice from 1,600,000,000 to 100,000,000. The next and more obvious restriction is that of age. The position may be one to preclude those under eighteen years of age or over sixty. This age restriction culls out two-thirds of the hundred million. Most 36 Popular Science Monthly positions are limited to one sex or the other, and this cuts off another half. We are now down to about 16,000,000. Thus in a few minutes and without expense we have excluded ninety-nine out of a hundred 15. By Physical Soundness 16. By Special or Technical Education 17. By Temperament 18. By Aptitudes 19. By Sympathy 20. By Predominant Type (Vital, Motive or Mental) Mental-motive Type. In- dependent; alert and opti- mistic; observant; self-suffi- cient; a good speaker; de- termined and positive; clear in argument; energetic and openminded; progressive; active and energetic; public- Mental Type. Mild and amiable; tolerant but posi- tive; slow and deliberate; clear thinker; not excitable; broad in views; willing to hear both sides of a question; open to conviction; but not swayed by arguments unless convinced of their truth Mental-motive Type. Clear in views; good talker; de- cided but reasonable; sin- cere; likes to find out the truth about any subject; broad in thought; thorough and conscientious; not easi- ly influenced; convincing in above-board spirited man; socially active of all the living persons. Real selection has scarcely yet begun. There is no particular sequence to be observed in applying the exclusion tests. Sometimes one characteristic is more im- portant than another. Age may be more important than sex, nationality may be more important than race, education be more important than natural gift, experi- ence be more important than ability. The Standard by Which Men Are Judged In semi-logical sequence: 1. The First Decision Is Between Uncarnate and Incarnate 2. Between Human and Other Life 3. By Sex 4. By Race 5. By Age 6. By Nationality 7. By Eugenics or Heredity 8. By Mental Soundness 9. By Moral Soundness 10. By Industrial Soundness 11. By Early Environment 12. By Training 13. By General Education 14. By Experience argument; . By Size (Tall or Short) . By Texture (Coarse-grained or Fine-grained) By Coloring (Blonde or Brunette) . By Body Build . By Shape. There are other subdivisions, so many in fact that they interest only specialists. It is evident that most of us in selecting employees pay some attention to the sixteenth requirement—special education. We are apt to overlook the importance of heredity (7), moral soundness (9), industrial soundness (10). Very few pay any attention to tempera- ment (17), aptitude (18), type (20); undue prominence being given to sympathy (19). Size (21) often is carefully considered, but not texture (22), coloring (23), body build (24), and shape (25). Yet every one of these twenty-five considerations would be applied by any man interested in thorough- breds, whether pigeons, chickens, horses, or any other domestic animal. In selecting men who are much less uni- form than finely bred animals, it is not so easy in advance to predetermine tempera- NN NNN wm WN dustrial or moral unfitness. I saved time by acting on impressions; I wasted . in the end thousands of dollars. The immense difference in earning power of a good combination of materials, equipment and men, com- pared with a poor combina- tionis notrealized. Ifthe net value produced by a thirty per cent machinist amounts to one hundred dollars a year, the net value of a one- hundred per cent machinist may be between six thou- sand dollars and seven thou- sand dollars. If we were certain that the person se- lected would stay perma- nently we could well afford a one thousand dollar or even a five thousand dollar- test. But we are not cer- tain. Why? Because we don’t know! Because it is easier to take refuge in plausible objections than to exercise care and do some thinking we refuse to select _ carefully, assuming that it is costly and difficult. How It Works In Practice While it is true that it PES et A Re ee ty Te Ee RET ey ey EE ay Bat f, PAS, _ any man or woman in all _ respects, the whole life _ being perhaps not long _ enough, it is equally cer- _ tain that a great many _ tests, weeding out all ex- _ cept the one best in a hun- _ dred, can be rapidly and _ inexpensively applied. _ Recently a young man _ Was wanted for a minor _ technical position on a rail- _foad. The selection was _ left to me. The following advertisement was inserted _ im several of the large _ Metropolitan dailies: Ay oa? ment and aptitude, or to know instinctively the effect of size, texture, coloring, etc. In the past it often happened to me to be _ dazzled by a man’s mentality or a woman’s charm, so that I was totally blind to in- takes a long while to test - Popular Science Monthly “WANTED: Young man, American, technically educated, of good address for a $60.00 a month position with railroad company. probation then possibility of permanent employment and promotion. Send three post-card photographs, profile, full face, full figure.” Motive-mental Type. Ob- servant; politic; secretive; energetic; alert and active; quick to grasp a situation; good at investigating; criti- cal; inquisitive but tactful; agreeable, plausible manner; practical and systematic; will follow up a subject until it is satisfactorily completed Mental-motive Type. Sys- tematic; exact and conven- tional; critical; not easily influenced; conscientious and reliable; not venturesome— must see his way clear; not impulsive; self-restrained; severe but reasonable; just 37 Three months About three hundred applications were accom- panied by photographs. Over two hundred and ninety were rejected in one afternoon on account of some manifest and undesir- able quality. Some of them showed by dress, bearing and expression that they were socially and other- * wise impossible. Others were belligerant, obstinate, unteachable, ill- tempered, cynical, self- indulgent, dissipated, de- ceitful; unreliable. Others were weak. The. whole three hundred graded off from a very desirable middle ground of good balance, aptitude and character into extremes of badness in one direction and weakness in the other di- rection. The ten picked out as wholly desirable were sub- jected to further tests. Al- though we only wanted two we finally took four. They were so good we were un- willing to lose them. Their work has certainly proved that we were not wrong in selecting them. We use the photographic method solely because of its rapidity for a first screening. Personal inspec- tion is very much better but it is not always feasible, as applicants may be scat- tered over a wide area. Do I attempt to read photo- graphs myself in selecting employees ? I do not any more than I operate the typewriter or the adding machine or keep the books or develop photo- graphs or cook my own food or make my own clothes. I employ specialists. Housekeeping Made Easy A hinge for interchangeable screen and storm doors. The two parts are interlocking and permanently attached, ball-and- socket style, one to the door - frame and the other to the door The up-to-the-minute baby car- riage has its electric gong and batteries, operated by a con- veniently located push-button, preferably on the handle, to clear the pathway of the carriage P y . A mahogany ther- mometer which also serves aS a paper weight for the desk At left below: A combination comb and brush, either part of which may be used separately or both together. The comb, which may be either large or small, locks into a slot in the brush At right: A teaball- spoon with a hinged top which fastens down with a clasp during the process of tea-making. The: principal advan- tage over the ordi- WW, ‘ | wn 1 hil nary tea-ball lies / \ | UPR a ye | Pe the handle | \ hi Two saucer-shaped sharpening An egg-beater, of stonespivoted between U-shaped heavy glass with a arms of a handle, for sharpen- ing knives without the least danger of cutting the hands An ironing outfit comprising a nine by twenty-one-inch board weighing one pound and a light- weight electriciron andcord,for plunger having two travelers and light housekeeping separate d_ dashers A new type of toothbrush which has the approved rotary motion. It oper- ates back and forth, also, by means of a plunger rod -which is con- trolled by the finger and thumb, so that it may be made to reach all parts of the mouth Above: The most convenient strainer we have seen yet. It fastens over the rim of any size _ pot or saucepan Housekeeping Made Easy : fourth of the gas consumed by the burner on the left © A. metal soap dish that will hold soap of al- most any shape. It may be fast- ened to the or- dinary faucet soap dish with solder or a small machine screw. It is commo- dious in size and the soap cannot slip off A collapsible supporting frame for a bassinet. It is unusually strong and may be folded up compactly and stored away Above: A kitchen reminder plate. In the center is a pin from which pointers are led to the labeled sections The hood fitted over the burner at the right drives © ) the flame inward, conserving the heat and saving one | Me IE ti, se IS CL ORM T IEA SIE BE A ABI ei SNS ATEN NTE IE BO SEE IE TET IS SUA EE ES A leather strap A suction cup attached to the garden hose, This set of picture Serves as a coin utilizes the pressure of the water system to hooks does away Purse and alsoas an clean drains. The force is constant and the with wires for umbrella holder work is accomplished in about thirty seconds hanging pictures ont 40 Popular Science Monthly - ee % > ae Fi ‘ ee EWE In spite of a five mile current, one hundred and fifty tons of pipe were laid in eighty hours. The work was carried on without mishap and has held against severe floods and record-breaking tides Laying Pipes in a Treacherous New Zealand River ITH equipment hastily constructed to meet the difficulties of the occa- sion, a company of engineers laid pipe- lines across one of the swiftest of New Zealand streams, the Teremakau River. This pipe-line is an extension of the Government water-race to supply the Kumura gold fields. The sections of pipe were laid from specially constructed pon- toons, one being joined to the other as the pontoon progressed. The work was carried on without mishaps in spite of a five-mile current. Altogether one hundred and fifty tons of pipe were laid in eighty hours. Since the pipe crossing has been installed, the river has experienced a number of severe floods. On one occasion its width increased from six hundred and fifty feet, which is normal, to nearly three thousand feet. A Fuel-Oil Burner Which Provides Ideal Combustion AEN fuel-oii. burner has been designed by Grover C. Long, of Lakeland, Florida, to eliminate all free oil from the furnace and to give continuous operation, wide range of capacity and as nearly ideal vaporiza- tion and combustion as possible. In the illustration the metal body contains acoil and a pipe which con- veys the steam-oil gas to the fur- nace. The adjusting wheel is used for varying the capacity of the coil, and the coil is heated by the steam enter- ing at the top of the body and passing around the coil. A guide maintains the coil centrally in the body. A head on the coil has slots through which the oil enters the body after being heated. A valve controls the oil supply, and also allows live 'steam to pass through the coil for cleaning purposes. Fuel-oil is admitted into the coil through the oil valve, the coil being heated to a high temperature by the steam admitted at the top of the burner. The oil, in passing through the coil, is heated to a point at or above the flash and is ejected through a series of holes in the head, where it combines with the steam that flows in a different plane at a high velocity, atomizing and vaporizing the hot oil from the coil. The vapor thus formed then flows at a reduced velocity along the conveying pipe and finally emerges into the furnace through the tip at the right of the illustration. Roo : VAPOR TIP ADJUSTING WHEEL OIL Detail drawing showing the piping and construction of the fuel oil burner to be used in connection with furnaces Popular Science Monthly 41 Prince, the Only Ice-Skating Bear in the World RINCE, the Skating Bear, is not a left-over from last year’s skating craze. He skated in his native Russia long before society ever heard of the “figure eight” and the “flying Dutchman.” To be exact, Prince has been skating for the past five years, most of that time on roller-skates. He came to New York-this winter to show the skat- ing multitudes how a Russian brown bear can skate gracefully —and fall down gracefully, too. That is something no human can do. In the “Who’s Who Among Bears” Prince is listed as the only ice-skating bear in the world. He wears a number seven’shoe, laced in front, if you please. His skates are double-runners and are securely fastened to the shoes. When Prince skates he straightens up on his hind legs and then strikes off in a leisurely manner, increasing his speed as he pro- gresses. His owners have to watch him carefully to see that he does not overheat himself. But by far the most remarkable thing about Prince is his faculty of ‘‘feeling a fall coming on,” according to his owners. When Prince feels himself about to hit the ice or the ice to hit him he bends his back in about the same position in which he is shown in the pho- tograph, and then simply sits down. SS i , —— — © Am. Press ae Prince wears a number seven regulation ice- skating shoe attached to double-runner skates ee A Maternity Hospital’s Method of Identifying Infants MODIFICATION of the Bertillon system has been adopted by a Chicago maternity hospital'*for identifying its tiny charges.’ Before the infant is an hour old a footprint “record -is taken, ‘the usual mode of- procedure being to smear the’little foot with printers’ ink and _ press “it against a sheet of white paper. The ink is then removed from_ the foot with absorbent cotton saturated with alcohol or benzine. In another and cleaner method recently adopted for the same purpose, cold cream is em- ployed instead of printers’ ink. The impression is made in grease on the white paper and sprinkled with pow- dered charcoal to bring it out clearly. The record is then filed away in an en- velope with theother data of the case. Riding a Bicycle on Your Stomach—One Way of Getting There HY ride a bicycle the usual way when you can lie down on it and kick yourself along just as you kick the covers off the bed each morning? After you ride a dozen miles or more your stomach may get sore, but that shouldn’t bother you. Just think how foolish you are making all the other bicycle riders look? G. A. Phillips, of Chicago, IIl., made a whole grandstand full of spectators look enviously at him when he dem- onstrated to them at the Newark, N. J., Velodrome how easy it was to sprawl over his built-to-order bicycle and wheel himself around — the track. He covered a half mile un- paced in fifty-nine and two- fifths seconds, which isn’t so bad when you take into con- A freak bicycle which enables the rider to kick his way along. He kicked a half mile in less than a minute sideration all the comfort he enjoyed during his travel. The Modern Scientific Detective By A. D. Montgomery The following article is published with the cooperation of the New York Police Depart- ment. Inspector Faurot, well known throughout the country as the head of one of the ablest detective bureaus in the country, staged the crime which is illustrated in the accompanying photographs. The pictures have been made with the sole idea of illustrat- ing the scientific methods which are now employed by I nspector Faurot and his men in bringing a criminal to book.—EDITOR. HE last person who had seen the mining engineer alive was the clean- ing woman. She had left him in his office at 5.30 o'clock in the evening. The office force had gone home, and he had remained to finish up some work. In the morning he was found bowed down over his desk—stabbed to death. Evidently he had been dead for many hours, and the murderer had had ample time to effect his escape. There must have been a brief struggle. _Apparently he had tried to summon assistance by telephone before he was killed. When Inspector Faurot appeared on the scene, the first step was to photograph the room from every angle. Why? Because the relative positions of clues might prove The first thing the police do on reaching the scene of a murder is to photograph the room before anything is touched. The photograph above shows where a particu- larly baffling murder wascommitted. The murdered man fell forward with his head on the desk. Had it not been for the pool of blood on the floor, the overturned chair and the fallen telephone it might seem that he had simply fallen asleep over his work. The crime was committed after business hours and was not discovered until the next day so that the murderer had time to escape. Yet he was arrested 42 of importance, and these positions might be disturbed by a careless rummaging around. Then began a minute examination of the room. Not a square inch was over- looked—not a scratch, not a stain. A’ few days later Inspector Faurot summoned one of his men. “Look for a man who has consumption, who has dark hair and who owns a blue serge suit,’”’ said the Inspector. Two enemies of the murdered man were arrested. One of them had been associated with him in mining work and the other had incurred his displeasure by requesting him to make a false report.. One of the two had a cough. His sputum was examined and found to be full of tuberculosis germs. Unable to prove an alibi, he broke down and confessed. It is perfectly apparent that science played some part in this tracking of a criminal. But how? Like all modern detectives, Inspector Faurot calls in chemists to help him. He uses their special knowledge as he would a tool. He brought with him to the scene The detec- The murderer spat upon the floor. tives discovered it and are taking a sample of the sputum for examination in the laboratory Popular Science Monthly Dr. Klein and Dr. Pascini of New York’s Central Testing Labora- tory—a seven-story building filled with the latest scien- tific paraphernalia, equip- to test anything from steel girders to fly- specks. No weapons or clues were to be found. A bundle of papers held together by a leather strap had been opened, but whether by the mining engineer or his mur- derer, could not be determined. The end of the strap had been broken off. The piece was missing. Follow- ing the instructions of Inspector Faurot, the chemists took that piece of strap into their possession. The inspector observed that someone had spat upon the floor. The two chemists took a sample of this sputum. The inspector further observed that there was what appeared to be a blood-stain on the door-knob. He examined this for finger- prints. There was none, because the murderer had so moved his hand that a clear finger-print was not obtainable. Nevertheless, the door-knob was removed and taken to the labo- ratory. Once in the labora- tory with the evidence thus collected, the chem- ists began their work. Inspector Faurot discovers what may be a trace of blood on the door-knob At right: A photograph of the blood as it appeared under the microscope 43 Under the microscope, tubercle bacilli were immediately identi- fied. At once the search was narrowed down to a man who had _ consumption, who spat freely and who probably coughed. Next, the stain found on the door-knob was tested. Was it or was it not human _ blood? A delicate test was made with a _ rabbit which had been injected with human _ serum. The. serum obtained from aé rabbit thus treated is a sensitive reagent which at once reveals the presence of human blood in a solu- tion. The chemists found that the stain on the door-knob was indeed that of human blood. But of what human being? An- other test was made for malarial parasitic and other organisms. So delicate are blood tests that it is sometimes pos- sible to statewith certainty thata given sample. of blood has been taken Above: Inspector Faurot holding the door-knob while Dr. Klein tests the blood print. Dr. Pascini is examining under the microscope scrapings from the victim’s finger-nails. The rabbit will be used in the blood tests. At left: The central hair was found in the nail-scrapings ie Testing two pieces of strap, one found at the scene of the murder, the other in a suspect’s pocket from an anaemic person. Often the field is narrowed down to one or two persons. The chemists examined the scrapings from the murdered . man’s finger-nails. Under the microscope they found shreds of human hair and fine particles of blue cloth. The murdered man had worn a suit of dark gray. There was no trace of blue dye in it. Evidently, the cloth must have been torn from the coat of the murderer. With the chemists’ report before him, Inspector Faurot narrowed the _ search And the chemical and microscopic clues furnished by the Central Testing Labora- tory enabled him at once to charge the tubercular suspect with the crime. But what of the strap? How did that figure in the case? ~ Was it the same as the piece found in the suspect’s coat pocket? To answer the question, comparative tests were carried out in the Central Testing Laboratory. Both pieces were stretched until they broke. Thus their tensile strength was determined. The readings of the machine were identical for both pieces. When the suspect confessed, he said that he had opened the bundle of papers hoping to find an old mining report which he could use to make a favorable report on his mine. He had intended to forge the murdered man’s signature. FAN down to the mining engineer’s two enemies. sx‘ Popular Science Monthly A Pneumatic Device for Destroying Devastating Animals T has been estimated by the Govern- ment that ten million dollars’ worth of crops are annually destroyed by ground squirrels in the United States. Besides, these animals are said to transmit such diseases as the Bubonic plague. To make war upon them, therefore, an unusually handy and effective device has been in- vented by Irving D. Charlton and Professor W. T. Shaw, of the Department of Zoology, State College of Washington. It consists of a circular container which is filled with some poisonous liquid such as carbon bisulphide. A handle is geared to a suction fan in the device. As it is turned the fan causes a current of air to enter the opening formed by the inner wall of the circular container. The air current strikes against a perforated disk which is mounted on the fan-shaft and which rotates with it. The air is then deflected and flows towards the outer rim of the disk, some of it going through the perforations into the liquid in the container and some of it going through the wetted perforations nearer the top of the device. The air then proceeds along towards the fan, carrying some vaporized liquid with it. On reaching the fan the mixture of vaporized liquid and air is forced by the fan down the discharge pipe. DRAINING Pais CcocK FAN CASING ‘| PERFORATED DISK oT OPENING FOR AP | AIR CURRENT LiQuid CONTAINER R DISCHARGING 3 POISONOUS t GASES The gas is forced through the pipe into the burrow and the animals therein are asphyxiated A Fireless Locomotive It is run on live steam secured from the power plant on the fac- tory site and stored in the engine tank until gradually exhausted ed consists of a large, round-ended tank with a false end at the front and fitted with only such appa- ratus as is required for the control of the steam to the cylinders. The latter, all the driving mechanism and the outside lagging to prevent heat radiation are exactly like those of an ordinary loco- motive. Three crosswise perforated baffle plates are fitted in the tank. These serve to prevent the water from surging from one end to the other and to prevent the locomotive from rocking. In operation, the tank is first filled about half full of water. This enters through a valve at the front and passes into and out of a long perforated pipe extending the full length of the tank near the bottom. Then live steam from the power plant on the factory site is admitted to the tank through the same pipe as was the water. By the time the pressure be- tween the boiler and the tank is equalized, generally at one hundred and fifty pounds, the water level in the tank will be raised considerably and the temperature of the water will be nearly equal to that of the steam by which it is charged, about three ee locomotive illustrat- [> THROTTLE VALVE - es . Se a = * For freight-car switching service in and around industrial plants and factories, the fireless locomotive meets an urgent need hundred and seventy degrees Fahrenheit. The steam is then drawn off through a throttle-valve in a dome in the tank top and led through a pipe to a reducing-valve in the false front end of the tank. This valve reduces the pressure of the steam to between sixty and sixty-five pounds per square inch before it is led to the cylinders. These are especially large in diameter so that the piston area is such that the locomo- tive can be moved when the steam is at a pressure of four pounds. The exhaust steam is carried out through a pipe in the stack as shown. As the steam is used, the pressure in the tank becomes Wi] steam AND I} WATER CHARGING The Gielees locomotive has no boiler and no means of provid- ing fire. Outwardly, however, it resembles the steam engine less and less, allowing the water to evaporate gradually and maintain a steam supply until it has been depleted to the point where it is no longer sufficiently effective. 46 Popular Science Monthly Invading the Lofty Precincts of the Bald Eagle with a Camera N pictures all - babies-look jj alike, whether they are princes of the blood or mere editors’ in- fants. The ac- companying illustration, for instance, might easily pass for a newly hatched chick in the nest of an old pet hen. It tells nothing of the giant ragged cliffs overhanging the Rio Grande River, on the summit of one of which the nest was made by a great kingly bald eagle which could easily gouge out the eyes or tear open the scalp of the daring photographers. The picture was made by . men in the employ of the Reclamation Service. Need- less to say, the mother bird was not present to pose her baby before the camera. Such intimate glimpses of an eagle’s nest are as scarce as the proverbial hens’ teeth Is a Hero Judged by the Number of His Scars? Just Look at the Car Below HE dispatch- carriers of an army are its nerves, transmit- ting messages from all branches to the head. When . telephone and telegraph systems are de- moralized auto- mobiles are pressed into service. The accom- panying illustra- tion shows a bullet -riddled French army automobile that carried three dispatch-carriers across a dangerous zone on the Somme fighting front. German bullets pierced it through and through, ripping the tires off the rims, tearing the engine-hood from its moorings, cutting through both sides of the car, and mushrooming against its internal parts but the car reached its destination with its mechanism intact and practically uninjured. ak Ew a © Underwood and Under- wood, N. Y. Although the car was rid- dled by bullets it carried its three occupants to their destination. The chauffeur was severely wounded but he stuck to the wheel Popular Science Monthly 47 Saving the Shattered Legs of the Fighting Man VEN amidst the horrors of this present war the soldier of today is better off than ever before.. At his beck and call are the fore- most surgeons of Europe and the most up-to-date hospital equipment in the world. Never was there a war in which the injured fighter was given such expert treatment. One of the most important tasks devolving upon the surgeon is to prevent soldiers with shattered legs from be- coming cripples for lite. The accompanying illustration shows an apparatus employed to save a soldier’s leg severely injured by a shell. Such an apparatus was used in our Civil War with great success. Dr. Fred H. Albee, who recently returned to this country from the American Ambulance Hospital at Neuilly-sur-Seine, France, where the photograph illustrated was taken, counted one hundred and ten sol- diers with their shattered legs in slings. The apparatus consists of weights, pul- leys and rubber bandages to support the leg in a position where the open wound will heal quickly and where the bones will knit to- gether without causing the leg to be too short or too long. From time to time X-Ray pictures are taken to see that the bones are growing together properly. Where a simple frac- ture of the bone has taken place the leg is placed in a cast, but when the flesh has been ripped and the bone badly shattered a special scaffold has to be erected over the patient’s bed and pul- leys and weights util- ized to enable the bones to grow to- gether in their cor- rect positions. Sometimes it is necessary to exert great pres- Sure to prevent the bones from shortening. Winchendon, Mass., A scene around one of the many toy factories at the toy town of America By means of weights and pulleys and spring devices the leg is exercised judiciously and prevented from shortening It Must Be Great to Be a Boy ina *‘Santa Claus’? Town MONG the children it has been gen- erally reported for ages that the head- quarters of the jolly patron saint of Christ- mas is somewhere in the vicinity of the North Pole. But this theory has been ex- ploded both by Peary and Dr. Cook, so that even the tiniest youngsters now discredit it. Germany has been recognized as a great distributing center, if not the actual abode of the saint; but anyone will realize that the condition of affairs in Europe just now are not congenial to a saint. However, we have it on good authority that Winchendon, Mass., is now the favored spot. There the principal occupation of the grown-up residents is the manufacture of toys, and there the after- school hours of the chil- dren are spent in the neighborhood of the fac- tories, on the lookout for a chance at trying- out some of the sample articles, as in the photograph on the left. So many of these great toy factories are now running full blast, that Winchen- don has gained the name of the Toy Town of the whole. United States. ~ © Int. Film Serv This Typewriter Is a Self. Starter indented lines, the new self-starting device fitted on type- writers of one prominent make, starts the carriage instantly at the correct starting point by simply pressing one of five keys. When it is realized that the writing of the average letter requires twelve dead stops and that each stop means an average time loss of four seconds, the yearly saving attributable to the After the indicators on the back of the machine are set the typist is relieved of the necessity for any mental computation in the operation of the machine “SLIMINATING the hand settings of a typewriter carriage for the writing of It saves about four seconds of the time required for each letter in the operation of the old-style sel- ector mechanism. Another ad- vantage of the self-starter is that the mechanism operates from either end of the line. If the carriage has passed the starting point of the next line of writing it is not necessary to return to the beginning of the line and then jump forward to reach the proper point. It can be jumped back instantly to the starting point desired. The importance of this ad-- vantage can be understood by noting the starting points of the indented lines of the average letter. In most cases it will be found that the termination of the last writing line is beyond the starting point of the next indented line. The operation of the device is accomplished by the use of a reversibie rack on the back of’ the machine. Different shaped stop pieces can be set at any desired positions on the rack. Stop pawls operated from the — self-starter keys by levers come into contact with the stops accord- ing to the shapes of the latter which are so de- device will be appreciated. The self-starter is an improvement on the old column selector previously used on some typewriters in that after the indicators on the back of the machine are set, each of the self- starter keys indicates the same starting point irre- spective of the position of the carriage on the line. This relieves the operator of the necessity of any mental computation in the operation of the _ keys, which from the mechanical standpoint, was one of the most serious drawbacks STOP PAWLS REVERSIBLE RACK. PA STARTER LEVERS: fir STARTER KEYS \" Pawls operated from the self- starter keys contact the stops 48 signed that the movement of, say, the third key per- mits the first two stops to be jumped. This enables the carriage to be moved immediately to any de- sired stop, no matter whether it is to the right or left of the stop. The device will be ap- preciated most especially by the typists, who will realize more vividly than — others the meaning of a few seconds saved from the time required for the writing of each letter or the spacing of each tabu- lated statement. —_— in a Reforming Bad Boys with Egg-Shells. Distracted Parents Please Note T was Christopher Columbus who first advertised the possibility of standing an egg on end; but it re- mained for the residents of a suburb of Dayton, Ohio, to profit by the ability to utilize the shell in its sta- tionary position. The method em- ployed is similar to that used by Columbus, except that the contents of the egg-shell may first be eaten or used for other purposes; afterward the shell is wiped off and the large end is carefully chipped so that the shell stands securely. The profit comes in utilizing the shell for starting a window garden. The idea was first conceived at a settle- ment house in the suburb mentioned, in an effort to interest and reform the bad boys of the neighborhood. The little plants were started in the dainty egg-shell cases, ’ and, being given plenty of fresh air, sun- shine and water, they grew first in the sunny windows of the settlement house and afterwards in the homes of the chil- ' dren, whose interest was aroused and held by the novelty of the idea as well as by the fascina- tion of watching things grow. In this way the settlement workers obtained not only companionship of the chil- dren but also an entrée into their homes. The egg-shells take the place of the first little pots in which the seeds are planted. But as the plants grow to _ Suitable size for trans- planting, they are _ placed, shells and _ all, directly into holes made for them in the ground. The shells hold the water and dirt so long _ as they are not in the _ ground, but they soon "crack or rot off after 4 Popular Science Monthly Only a very acrobatic cat or squirrel iin sens a s@e oa f @ #7 7% oil ; e-F clay pots and are later set into the ground Preventing Cats and Squirrels from Climbing Trees N effective guard to prevent cats and squirrels from climbing trees to de- stroy birds has been put on the market by a western manufacturer. It is nothing more than a wire net with protruding points which expand with the growth of the tree trunk. The guard can be fitted to large and small trees, and there is no animal of the smaller class agile enough to climb over it. Several years ago when the western part of Colo- rado was overrun with jackrabbits the farmers were at a loss to know what to do to prevent their trees and haystacks from being destroyed. The rabbits attacked everything edible in sight, including trees and even thorny bushes. Of course, the farmers could not protect their haystacks but they did devise a means to save their trees. They bought all the scrap tin they could and fashioned it into guards similar in being planted, and the could climb over this tree-guard design to the one illus- roots of the plants grow trated. These were On undisturbed. This is a decided advan- securely nailed to the trees. It wasn’t tage over the ordinary method of potting, and results in a quicker growth than would _ be possible with clay pots, from which the roots would have to be transplanted at " least once and usually twice. ale a. long before the rabbits passed on to a more hospitable section of the country. In the spring, rolls of cotton saturated with a vermicide are placed over the top of the wires to keep caterpillars away. 50 p Popular Science Monthly With the ever-ready motorcycle, hills are not necessary adjuncts to bob-sledding. This machine develops between sixteen and twenty horsepower and is capable of hauling a hundred men The Motorcycle Becomes Popular for Sledding Parties HE horses on the Adirondack and Swiss lakes, who earn their oats during the winter months by pulling long bob- sleds of pleasure seekers over the ice, stand a fair chance of resigning in favor of the motorcycle. The illustration shows thirteen men enjoying a ride on the power exerted by one motorcycle. If there were forty men on the bob-sled instead of eleven the motor- cycle wouldn’t say a thing but would speed along possibly at increased rate to show its capability. The machine develops between sixteen and twenty horsepower, and through the reduced gear could pull as many as a hundred men with compara- tive ease. Acchain on the rear wheel is the only concession which is made to the ice. There is one record of where a motorcycle pulled a five-ton truck with sixty-two full- grown and healthy Americans aboard. Of course this record was not made on ice. Turning a Motorcycle Into a ~ Motor Ice-Sled ITH the frozen Hudson River stretch- ing away in the distance like a broad ribbon of smooth glass, Michael Cimorelli couldn’t resist the temptation to make a motor ice-boat out of the motorcycle that was standing idle in the garage. Accordingly, he took his machine apart and by using the engine, rear wheel and accessories made an ice-boat which covered a mile and seven-eighths in two minutes. — Part of the frame of the motorcycle was anchored in the fore part of the ice-boat and the rear wheel was carried in the forks to propel the boat. Tire chains gave trac- tion over the ice and the rear rudder, steered from the wheel, guided the boat. The gasoline tank was placed in the extreme rear behind the driver’s seat as shown in the illustration below. The boat is capable of speeding over the ice in record time, or of navigating the city streets during weather suitable for sleighing. Part of the frame of the motorcycle is anchored in the fore part of the ice-boat and the rear wheel is carried in the forks to propel the boat. The gasoline tank is in the rear Popular Science Monthly With the motorcycle ice plow the surface is first cut away one-eighth of an inch with a steel blade. Smoothing Skating Surfaces With a Motorcycle Ice Plow HE motorcycle plow is not, as the name may seem to indicate, a new solution of the motor tractor question. It is an entirely new creation—a scraper and a planer for cleaning away the ridges caused by sharp skates on ice rinks. By its use the skating surface on thick ice may be kept in good con- dition con- tinually dur- ing the skat- After the surface is cut and smooth, the scrap- ings are removed by means of an iron scoop which trails along be- hind the motorcycle ing season. The motorcycle is especially geared for this task, so that at runs slowly and smoothly when in use, making not more than from three to four miles an hour. The rough ice surface is first scraped clean and smooth by a knife-blade, which cuts away about one-eighth of an inch; then the scrapings are removed by a scoop. The rear tire is fitted with short, sharp spikes, so that the motorcycle has a firm grip on the slippery surface. The extra Wheel on the scraper gives a sure balance. The rear tire is fitted with short, sharp spikes. The inventor is astride the cycle Making a New Motorcycle Altitude Record on Mt. Hood N attempting to climb Mt. Hood recently a new motorcycle altitude record was established. The former record of seven thousand feet, made in 1914, was bettered by two thousand feet by a trio of motor- cycle enthusiasts who braved wind, storm, ice and snow. The record-holders started from Portland, Oregon, before six o’clock in the morning and arrived at Government Camp, situated sixty miles away, at seven o’clock. After resting for a few hours they started for Emergency Camp, four miles away, at two o'clock in the afternoon. This was one of the most trying ordeals ever experienced by motorcycle riders, the entire four miles of roadway consisting of rocks and boulders. However, the riders reached Emergency Camp in good condition. Afteran overnightrest theclimb was continued from Emergency Camp at five o’clock the following morning. For hours the three riders fought with steep grades and deep snow until the final goal of nine thousand feet was reached at nine o'clock. At this point the machines were obliged to run over a thick, hard crust of snow, and in some places the weight was too great for the snow, causing machine and driver to stop abruptly. Several times the crust-was only a thin sheet, so that t riders had towalkalong with their machines. The return trip to Government Camp was made under still more trying circum- stances, for the sun had melted the snow. 1 } Ai e Combining the Garage with the Home HE automobile enthusiast thinks of his car as something human. It is only natural, then, that he should plan its “sleeping quarters” with almost as much care as he would his per- sonal residence. In fact the garage should be treated as a part of the homeplace, if it is located on the same plot. It should be constructed of the same material and along the same lines as the house, and should be painted the some color. In the accompanying photographs picturesque ef- fects have been studied. On the left is a clock- tower garage erected on an elaborate suburban estate. Other designs show the garage incorpo- rated in terraces and a hillside, leading to the dwelling. The rounded sheet-metal type ‘is be- coming popular, and the all-glass model in the lower left corner of. the following page provides abundance of light. - Flowers and vines relieve the coldness of concrete or extremely plain structures. Stabling the Gasoline Horse at Home A iS 54 Popular Science Monthly A Brush Which Clears the Way for the Phonograph Needle O YOU really clean your phonograph _ records when you rub them off with a cloth? - Doesn’t the rub- bing compress some of the dust into the grooves? Arthur Herrman, of New York city, thinks so. He hastakenan ordinary brush and has attached it to the sound box in such a way as to dislodge all dust from the groove just before the needle reaches that particu- lar portion of the groove. _ His sweeper is composed of stiff bristles. It may be swung to an inactive position out of en- gagement with the record by turning it on its swivel connection. It is adapted for the playing of records having hill-and-dale or laterally cut grooves. just Doing Away with the Pick and Shovel in Excavations NTIL recently there were only two methods of excavating and handling dirt, stone and gravel. The one was by means of the pick and shovel, which is both expensive and slow. The other was by means of the steam shovel, which, while cheaper and quicker than the first way, The sweeper is clamped to the sound box and is moved along in front of the needle requires a large original purchasing outlay. To provide a happy medium, John Albrecht invented this ex- cavator and loader. The machine consists of a scraper and a loading plat- form. The scraper is of steel and scrapes up the dirt or gravel and carries it to the loading platform. It is pulled back and forth over the ground by a steel cable. A man guides it by two wooden handles. When the scraper reaches the platform it is full of dirt and ready to be dumped intoa wagon. Todo this it is drawn onto a skip, or steel box with only three sides. The skip is then lifted till it holds the scraper direct- ly over a shute down which the dirt slides into the waiting wagon. The machine is run by an electric motor and needs only two men to operate it, one to run the motor and the other to steer the scraper. When this excavator is used the wagons are loaded with dirt on the street instead of having to be driven into the excavation to be loaded, which would necessitate an extra team of horses to pull them out. In this way the great gap between the expensive steam shovel and the old hand method is bridged. The machine consists of a loading platform and a scraper, which, when filled with dirt, is drawn upon a three-sided steel. box which dumps the dirt into the waiting wagon Quarries into mushroom-beds. Farming in Your Cellar The French may lack land, but never ingenuity. So they cultivate p'ants which thrive without sunlight To make the beds for growing mushrooms horse manure is piled in ridges in quarries. » The spawn comes in the form of bricks HE underground cultivation of mush- rooms isa large industry in the vicinity c of Paris. The kind ordinarily grown is the common mushroom, the variety best un- derstood by cultivators. Noone knows the name of the genius in gardening who first took the’ spawn from the half-decomposed bed of dung where mushrooms had grown and then sowed it in fresh dung to obtain a second harvest. This method of ‘‘cellar farming,” as it may be called, arose in France in the latter part of the eighteenth century, but long before that period a cultivator named Chambry conceived the idea of turning abandoned subterranean The large profits he realized led a swarm of imitators to rent all the deserted quarries. Thus the raising of mushrooms became an established industry. Nowadays, these subterranean mush- toom-beds near Paris are on the left bank of the Seine, largely in the district between Meudon and Ivry. Formerly the galleries Tan as far as Paris, existing under the ' quarter Val-de-Grace. Of late years other excavations have been made in the suburbs between St. Germain and Argenteuil, while still others are to be found on the other side of Paris, between Romainville and Noisy-le-Sec. Modern facilities of trans- portation have led to the making of beds farther off from Paris in the valley of the Oise near Creil and Meru. The galleries are cut either in gypsum as at Argenteuil, or in white chalk, as at Meudon. The oldest of the galleries form labyrinths of narrow passages so low that workmen can- not walk through them without stooping. After securing good ventilation in an abandoned quarry a well is dug to make sure of the large amount of water necessary. After this, horse manure is prepared by piling it in heaps about a_ yard high. Sometimes a_ pile will contain a thousand wagon loads of material. The heap fer- ments in the air for three weeks, and i turned from time to time to check excessive fermentation: The mushroom does not develop properly in fresh manure. Fer- mentation gives the manure the necessary nutritive properties. After about twenty 1S 56 Popular Science Monthly days the manure is taken down to the beds where it is carefully heaped in ridges along galleries with rough walls. Small bricks or “‘leaves’’ of mushroom spawn are inserted in holes made in the ridges. The growth of this spawn, called by _ botanists “mycelium,” ischecked by dryness and quick- ened by humidity and heat. Thespawn throws out threads which spread in all directions and finally fill the entire ridge of manure. Mushrooms Require As Much Care As a Baby The skill of the cul- tivator reveals itself in adjusting local con- ditions to the require- ments of his’ beds. The chief difficulty arises from the enor- mous amount of air absorbed by mush- rooms. They die of suffocation easily. Not only must the galleries be thoroughly ven- tilated, but the air must be moist and changes of temperature must be avoided. Verily, young mushrooms are frail. The three kinds grown in the under- ground beds around Paris are: the white, which is small and delicate in flavor but does not bear transportation well; the light _ yellow—stronger, more productive bed near Paris. Entrance to a subterranean mushroom In many places aban- doned quarries are utilized in this way and less fragile than the first, and the gray. This last has a rich odor, but the deep color acquired at a late stage of growth lowers its price in the markets. The ‘“‘sets’”’ of spawn intro- duced into the manure de- generate after a while, so that raisers seldom cultivate from one seeding more than two or three years. They prefer to take fresh spawn obtained by scientific methods which allow a selection of mushrooms, and then to reproduce the best by direct germ- ination of the spores. There are in the De-. partment of the Seine two hundred and fifty | mushroom-beds, some of great extent, owned by eighty proprietors; the annual value of the yield near Paris is about $2,500,000. Other vegetable growths also receive subterranean cultivation both in other parts of France and elsewhere. French and Belgian market gardeners grow certain vegetables out of season and blanch them underground, one of the most curious exam- ples of the method being the cultivation of wild chicory, a form of endive. Celery and plants of similar nature are also grown and blanched underground. Cutting potato sprouts with pruning shears after three weeks of growth in the underground molds. About three months later the potatoes are large enough to be marketed Growing Other Vegetables in Cellars Near Paris seed is sown in the open air & between April and June. At the beginning _ of winter the young chicory is taken up, the leaves cut off just above the neck and the chicory placed in heaps covered with leaves in a shed. A layer of manure is arranged in a dark cellar, and the roots tied in bundles are set in it. The chicory shoots out rapidly in the warm air. At the end of two or three weeks it is ready to use; no care is needed except occa- sional watering. Early potatoes have also been grown underground. The potatoes are placed on beds of garden mold laid on planks two feet from the ground. Thecellar or gallery must be absolutely dark. After three weeks the potato sprouts are cut down several inches. Two or three months later the sprouts are surrounded by a number of small white potatoes. The growths can be arranged so as to _ have a succession of new potatoes from October to March, when they arrive _ from the south. The method although ingenious, has not proved to be very __ profitable. ‘So far as mushrooms are concerned pelt ¥ fag dF Daa Rit Ti Pi heap pee es LI NA _ according to the Department of Agri- At right: A bed of endive in a subterranean passage. The cellar farms have been found especially useful for blanching vegetables Placing potatoes ina mold. The plantings are arranged so as to provide for a succession of new toes from October until March, after which time the demand is supplied from the South Popular Science Monthly 57 culture. Where there is a dry bottom on which to place the beds, where a uniform and moderate temperature can be maintained, and where the beds can be protected from wet, winds, draughts, and direct sunshine mushrooms will thrive. Testing Your Camera Lens How photographic lenses are given the third degree to unveil possible serious faults The lens is put in its holder on top of its own column. a camera in which is a strip of motion-picture film for taking pictures of a point of light HERE are several ways to “try” lenses—and many devices for the purpose. A camera is only as good as its lens, and the more severe the manu- facturer is toward his lens children, the better. When the lens-tester illustrated here gets through with a lens, he knows all about it. Its innermost secrets are all revealed. If a lens shows partiality to certain colors, which it should not, the tester finds it out. If the lens is suffering from astigmatism, the tester will show it. If it casts a drunken image, it has no chance of escape. Next to-a meteorite, the bench for test- ing lenses is about the heaviest thing for its size in existence. One is impressed, there- fore, when he discovers that it is built to hold a small microscope and a wee little lens about as heavy as a wet feather. Why should such an elephantine machine be necessary to test lenses? Because the test must be made without vibration, and the distance between lens and microscope 58 At the end of the microscope is must be known within one ten-thousandth part of an inch. Perhaps the heavy parts now begin to explain themselves. Before we describe this method of lens testing used in the kodak research labora- tory, it will be well to review the lens from its beginning. If you have ever forced a stick into a clear pool and observed how curiously the reflection is bent, you have the working analogy of what a lens does to light rays. Refraction, as it is called, is that property of a substance which bends light rays, or, | to be more accurate, which changes their direction. In the case of a lens, rays are bent so as to converge at a common point known as the focus. Simply stated, the problem is to grind glass into the proper curvature so as to focus rays at a given point. But the implied simplicity of this statement is most mis- leading. The difficulties that beset this curve grinding are legion. At the very outset in lens-making the difficulty—in grinding photographic es he can produce only spherical sur- ces. He can’t grind glass into parabolic urves; the basic principle in grinding 4 precludes that. So the lens maker, to come these difficulties, has to use kinds of glass and to combine the es made from these various kinds of s so to make the finished photographic jective. concave curves, some with convex _Wherever he get bee curves that fit—one being con- and one convex— to carry out his y object and together. at a on the film the - ttaasa baler his doughboard. After he has computed a lens, he passes it on ) the workman, who rin ds and assembles t exactly according to calculation. The omputer then sub- lits his lens to test on ie as bench. On is a tiny pin- of light, d that its color e varied. By this fans the bench can st a lens not only for ‘dinz light, but for 1. and green and yel- He grinds some glasses with Popular Science Monthly 5o es is faced with one insurmount- page). It forms a tiny image of the point of light across the room, which point of light is examined by the microscope. At the end of the microscope a little camera is placed, in which is a strip of motion-picture film. On this strip of film, pictures are taken of the point of light. The vertical strip at the left in the illus- tration below shows the sharpness of the image that the lens will give in the middle of the picture when the light is going straight through the center of the lens. But at the edge of a picture the light is not going straight but side- ways through the lens, and the real test of a. photographic lens is the. sharpness of the edges of a picture. Nearly all lenses will give-a sharp picture in the middle of the film, but only a really good one will give a sharp image at the edges. Sometimes instead of getting a point ‘Image at the edge ‘we get a ~short- line which changes its direction according to the exact focus of the lens, the line being vertical in one position and hori- zontal in another. (See middle strip in illus- tration.) This defect is called astigmatism. An even more curious defect is the blurring known as “‘coma,”’ the point being shown as a dot with luminous wings like those of an insect. (Vertical strip at right of illustration.) The lens-testing bench measures ex- actly all the devia- tions of the lens from its theoretical perfec- tion. Armed with this w and blue light as The lens is put in its ider on the top of its wn column (see illus- ation on preceding —— F Illustrations of the point of light. “ll. The strip at left shows a sharp picture in the middle of the film but blurred ends. center strip shows astigmatism, the lines changing direction. At right is the blurring called coma knowledge, the lens- computer can draw his curves and alter his construction until the lenses measure up to the highest standard. The 60 | Popular Science Monthly Press a button in the door-knob and ~ a lamp near the keyhole flashes up Finding the Keyhole at Night. Press a Button and a Light is Made OME people, on certain dire occasions in the small hours of the morning, find it difficult to locate the keyhole of their door. An Ohio inventor, however, has come to their rescue with a device for luring the latchkey to the proper place. He accomplishes this: with an arrangement which provides for the placing of an electric light pointing geometrically toward the keyhole. The light has a reflector attached to it which further. intensifies its illumina- tion. Theconnections to the light are made through a push-button which has been thoughtfully fitted directly into the door-knob. From the push-button, the wires lead to the batteries through contacts between -the door and the door-sill. Push the button and the circuit is closed and the lamp lighted. Combined with this is an alarm which is so. con- nected with the door-lock that as ‘soon as the key is placed in it, the alarm goes off, arousing the household. How They Wash Clothes with the Help of the Wind in Alaska ee Alaska and throughout the more or less frozen North, laundresses are prac- tically unknown. The miners do their own housekeeping, and their own launder- ing. The accompanying illustration shows a device which one of them constructed as a substitute for the washboard and tub. It is made of an old barrel-churn mounted on runners so that the miner can take it along to his work. A cylinder about thirty inches long and of the same diameter as the head of the churn was first constructed of- heavy galvanized iron. One end of this cylinder was left open, and the head of the churn was fastened to the open end. The cylin- der was then carefully balanced in the churn, and the churn-bearings were fast- ened on with rivets and solder to make them watertight. Two screens of galvanized wire of one- inch mesh were made. One of them was suspended from the movable head by one- quarter-inch galvanized iron rods, and the other was fastened to the cylinder, so that the two were about ten inches apart in the middle of the cylinder. The clothes are confined between the two screens. The water surges back and forth through them until they are clean, or as long as the churn is in motion. A large pin-wheel attached to the bearings furnishes the turning power. The miner leaves the machine in an exposed position and lets the wind do his washing A typical Manila home showing the crude methods which the natives employ for stretching and drying the rope material ANILA paper rarely sees the light / of day in Manila. It may be : ing plant in the islands, just started. by _ Americans, but that is not likely. _ In fact, Manila paper has nothing to do one. ‘with Manila at all. Like Manila paper, _ Manila rope was unknown in the Philip- ' pines until Americans established a _ modern rope factory in Manila. It is _ true that the natives made rope, miles of it, before our advent, but the crude, “hand-made output of the peasantry was _ Yarely exported—at least littlé in finished - ‘form came to us. _ The Philippines are -rich in rope _ material. Manila hemp is known over all __ the world because it finds its way where- €ver railroads, steamships, caravans, and _ dog-teams travel. Thehemp plant, which _ Cannot be distinguished from the banana _ Plantby those unfamiliar with thesubject, 2 thrives best in a volcanic soil. Soil of this « } f 2 included in the only paper-mak-: Rope Riches of the Philippines Practically all the hemp used: the world over for manufacture of rope comes from Philippine ports Hemp stripping by hand is muscle-develop- ing but slow. The bark is drawn over a toothed knife. to tear away the pulp 62 class is common over the entire Philippine archipelago. Due to this fact, practically all of the hemp used in the world for rope manufacture comes from Philippine ports. Silk and hemp are the two commonest cargoes carried by trans-Pacific ships when coming our way from the Far East. The British have always controlled the hemp growing industry of the Philippines. They controlled it in Spanish times, and they control it now. The natives raise it and the British buy and market it. Why this is so is a long story. Briefly, the situation may be traced to unsettled political policies. the natives for stripping the threads from the stalk American firms hesitate to invest capital in politically turbulent countries. Hemp grows wild in the islands, but it is also cultivated to a large extent. Despite the supervision of the British and the stewardship of the Spanish, we found the Filipinos handling hemp in ea Silk and hemp are the commonest cargoes from the Philippines. islands and-is also cultivated by the natives to a great extent. Popular Science Monthly the very crudest way when we became over- lords. Stripping hemp by hand meant hard work. Much of the crop was wasted, too. For this reason prices were high. Hemp threads are stripped from the trunk of the plant, a long green log, similar to an overgrown cornstalk. The strip, or bark, is drawn over a toothed knife, so that the pulp is torn. away from the threads. Americans were quick to see that a machine could be applied to do this work, and to do it better and very much faster than by hand. So alluring were the fortunes to be made from such a machine and so great was the need for it economically, that several successful hemp-stripping machines appeared on the market at about the same time. These machines are doing good work, but the poorer natives have been slow to adopt them because of a lack of money and because a machine that will do the work of ten or twenty poor peasants is looked upon as an industrial enemy. Hemp stripping by hand is healthful work. It develops rolls of hard muscles and affords fresh air, as the operations are usually carried on in the field. Pull- ing the pulpy slabs across the toothed knife is muscularly like boat-rowing. Natives having a small crop, bale it up and carry it into town on their shoulders for sale to the nearest agent of the British exporters. Native hand-made rope is too loosely woven together to have much commercial value outside the islands. Paes Hemp grows wild in the The British control the trade a dnees Science Monthly 63 ‘An \mericans quickly noted that = while all the raw material for | the world over, came |e ~ _ from Manila, little factory- finished rope was going abroad. ‘As a result an American com- pany was formed and a modern ‘plant for rope-making was built in Manila. _ A good hemp rope is hard, ut pliant, yellowish or green- ish gray in color, with a certain silvery or pearly luster. A d dark or blackish color indicates that the hemp has suffered _ from fermentation in the pro- cess of curing, and brown spots ow that the rope was spun hile the fibers were damp, _ and is consequently weak and soft in those places. Sometimes a rope is ade of inferior hemp on the outside, zo overed with yarn of good material. This may be detected by dissecting a portion of the rope. Other inferior ropes are made from short fibers, or with strands of unequal Tengths or uneven spinning, the rope in the fi t place appearing woolly, on account of the ends of the fibers projecting; in the latter case the irregularity of manufacture Ss evident on inspection. A test for ascertaining the purity of oe rope consists in forming balls of oose fiber of the ropes to be tested z and burning them com- pletely to ashes; pure Ma- ‘rope a ».~ . t t bE { i SPL ES, Pe De ‘) ais eu ee re See eee Caigasicur to England and western ports. rope comes from Manila, except certain inferior grades made from flax and Russian hcmp have much commercial value. been established in Manila and modern machinery installed The natives do make rope but it is too loosely woven to An American plant has now nila burns to a dull grayish-black ash; sisal leaves a whitish-gray ash; a combination of Manila and sisal yields a mixed ash. Manila hemp is frequently adulterated with New Zealand flax and Russian hemp, both of which are much inferior in strength. Rope in service deteriorates in two ways: the wear on the outer surface, which can be readily seen and the stretching, bend- ing, crushing and breaking of the inner fibers, which cannot be discovered without a careful examination. It is when rope is to be subjected to such severe bending and rough treatment that preliminary oiling of the fibers is important, if the life of the rope is to be long. All the raw material 64 Popular Science Monthly Combination Christmas Tree-Holder, Telephone Stand, and Tabouret CHRISTMAS tree holder has been i-\ invented which will prevent the usual litter, because it keeps the base of the tree in water. This keeps the branches fresh and alive so that the ‘‘needles” are not so prone to drop off. The device may also be used as a_ telephone stand, a jar- diniére stand, a vase support, or a hang- ing flower-pot holder. When the device is used as a Christmas tree holder, the tree stands in a cone with the pointed end down. This may-be filled with water to keep the branches supplied with moisture, so as to preserve the green- ness for the longest possible time. Thus the danger of fire is diminished, although it is ever present where the old- fashioned candles are employed. The total elimination of the fire danger is accomplished by the use of electric-light sets, which are supplied with varicolored bulbs and batteries complete at hardware and_ depart- ment stores. The holder is adjust- able for various sizes of trees. The legs may be detached and the cone suspended as a hanging flower-pot. The Christ- mas tree may be trim- med, sawed off at the proper height, and a board attached to make a telephone stand or tabouret. The receptacle for the water does not touch the floor. Hence, there is no damage to polished sur- faces from sweating. The tree is held rigidly upright with its stem in a vessel of fresh water How Do Birds Always Know Where They Are? ROFESSOR K.S. LASHLEY has com- pleted an investigation of the sense of direction in birds. This is called the problem of “orientation.” To ‘‘orient”’ means in straight English to know where you are. Dr. Lashley used the wild birds of the Florida Keys, known as noddy and sooty terns, in experiments. In their recognition of their nests, it was found that their eyes as well as their muscles are concerned. The birds showed no evidence of any special sense of locality such asa “magnetic sense’ or a “second sight.’’ Birds are no more ‘“‘mind readers’”’ than men are. Nor do they have any ability to re- trace their paths of flight by mem- ory. They recognize their nests. and their own young by muscle habits and eyesight. Dr. F: A. McDermoth, another — investigator, has observed the . oddities in the behavior of — houseflies: They have a strong tendency to go with air currents between 80 and 100 degrees. This explains why flies are so bad in hot weather, when it is about to rain. The heat usually ranges up-— wards towards one hun- dred, and the air travels along too slowly to cause | the vapor in it to evapo-— rate. The heat, humidity, — and slow movement of the © air gives the housefly its “fly time.” As pests, they — are then in their glory. - The Christmas-tree support has all-the-year-’round uses. It makes an attractive telephone stand, tabouret or flower-stand, and may even be used for hanging plants _A Rain Alarm to Make the Hired Girl Get Up and Close Windows NE of the countless young ~ American geniuses for whom is waiting the worthy task of carrying out some _ unrealized ambitions of Thomas Edison, has laid claim. to national atten- tion by the invention of an alarm _ apparatus which will wake up the _ housemaid by the loud clanging of a bell when the weather becomes rainy. The sixteen year old Edison in question lives in — _- Minneapolis. His deed was in- spired by his worried mother, ~ who complained that nobedy- _ woke up in the night when it 3 = : 2 4 rained, and that the water came % in at the windows and ruined z window curtains, rugs and other " household valuabies. The boy, who is a wireless en- _ thusiast-with an inner knowledge _ of the pranks that the electric current can be made to perform, _ got out wire, batteries, and tools, _ eonfiscated several articles from _ the kitchen, and set himself to _ the task. At the base of one of the Popular Science Monthly 65 The first drops of rain trickle down from the gutter to the funnel leading to the battery and cause the contact which rings the alarm gutters lédding from the eaves- trough he attached a device for making electric Contact as soon as the first few drops _ of rain fell. This device consists of a tin _ funnel beneath which is placed a jelly- = glass having two strips of spring-brass _ attached to its sides and terminating in its center. The strips are adjusted so that, when released, they spring together _ and send the current from con- _ veniently located _ batteries ‘Surging through a bell. Crys- _ tals of coarse salt hold the _ Springs apart. When water touches the crystals they _ dissolve. Thus contact is - made. Even if the salt should not dissolve it will ___ be saturated sufficiently to _ allow the current to pass. Wires lead from the brass _ Springs to several dry cells. A bell is located at the ___ head of the housemaid’s bed. The raindrops trickle down the eavestrough to the gutter, _ through the funnel and on until the con- __ tact is made which rings the bell. The eight-hour clock designed to abolish computations of time \RUBBER BED - An Ejight-Hour Clock for the Eight- Hour Day 1S bee was ink on the eight-hour law dry, when a California watchmaker devised the “eight-hour clock” and at the same time offered a plan for abolishing the confusion arising from the difference in time between various points on the continent. The new clock has but eight figures on the dial, with a small square in the center which shows M from one in the morning until eight; N fornoon,and £ for evening, the third division. The inventor makes this suggestion: Inaugurate a uniform time all through the United States, and let Washington, D. C., be the heart of our time system. The twenty-four hours of the day can be divided into three sets of eight hours and the different divisions indicated as M, N, and £, or D1, D2, and D3. This would eliminate time-computations. 66 es Science Monthly or massaging action without discomfort to thepatient. The two pump-cylindersarecon- nected by a bypass with a valve to regulate the pressure of air in the massaging tubes. Belts of different sizes may be readily at- tached to the apparatus, making it adapt- ~ able to a variety of treatments. Sleeping on a Mattress Filled with Water Es NE of the things needed by physi-' cians is a bed that can be heated or cooled according to the needs of the patient, and one that a patient can lie upon for months, if necessary, without getting bed sores. An inventor has filled this want with what he calls a water bed. The bottom and sides of the bed are’ built of galvanized steel, and the top is made of rubbered canvas. When this is filled with water it makes as soft a mat- tress as any one could desire. A reser- The eas Sp weer by prec susirgkostat voir is stationed at the head of the bed, ing inflation and deflation of the attached tubes which holds enough water to make the A Machine that Massages Your Pains _ pressure in the mattress the same at all Away with Air “> points. N air-operated massage apparatus The reservoir will hold one hinted with action somewhat like a milking pounds of ice for keeping the bed cool and machine has been devised, by Frank and comfortable for typhoid fever patients or Wilfred Shurtleff, Moline, Il. Elastic for anyone in the summer time. tubes are attached to the inner portion ‘ofa Under the foot of the bed is an oil stove broad belt, and irito these, flexible air-pipes. which has a flue that runs under the center are led. Air is pumped through these pipes — of thé bed to'the head. This artificial heat by a pump driven by an electric motor. “would be useful in case of a patient who was As the tubes are alternately inflated and suffering from surgical shock, hemorrhage, deflated, they perform a constantly shifting chillorcollapse. Athermometer is attached. ee os re The temperature of the : ee ' water is kept under con- ee stant control. Ice water is Ce used for fever patients & — : and heated water for suf- fam ferers from shock or chill _-CIRCULATING WATER yiNLET TO BLANKET BEER BLANKET OUTLET FROM BLANKET yy) INLET TO TANK : OUTLET FROM TANK EET METAL TAN How the Forest Service Gathers Pine Seeds Nature has tucked away the pine seeds so care- fully that it requires ingenuity to extract them : ATHERING seed of various species & of pine trees is an industry carried - on in the great national forests of the West by the United States Forest Ser- vice. The seed is used for reforestation on the government reservations and is also sold to private persons for the same. purpose. Each autumn the cones are both gathered in large quantities by employes of the Forest Service and bought by the bushel from persons who make a business of gathering them. When gathered, the cones are closed and hard and contain much sap. They are placed in bins under cover and allowed to dry out for a period of two months or more. The opening process is hastened by subjecting the cones to a heat of about one hun- dred degrees Fahrenheit for a period of from one to three days. The cones are placed in wire-bottomed trays, about two feet wide and three feet long, and the trays are stacked on tn ay i aa oa eal} The cones are gathered in large quantities and stacked in wire-bot- tomed trays to dry racks in a room where the drying process is carried on». The drying causes-the bracts or petal-like parts of the cone to spread out, thereby-releasing the seed. In order to shake the seed from the cone a churn-like device is utilized. It consists of a box’with ends of boards and sides of woven-wire screen. Through this passes a wooden axle supported by uprights. By ‘means of a handle at one end of the axle the churn is revolved rapidly; the seeds are shaken from the cones and fall through the wire screen to a sheet underneath. In order to separate the seed from their “wings,’ which are broken off by the violent churning of the cones, a fanning- mill is utilized. In the southwestern sec- tion of the country the use of a drying room or kiln is not necessary in order to open the cones and extract the pine seed. The cones: are placed in shallow bins in the open air. Ex- posure to the intense heat of the sun soon opens them up, where- upon they are put through the churn. A churn-like device is revolved rapidly to extract the seeds from the dried cones Pouring the cones into the churn. The seeds fall into a sheet-lined bin below 68 With Adjustable Stilts a Boy Can Grow ‘Up in a Minute O one remembers who invented the first. pair .of stilts. Fathers, grand- fe theke and as many ‘“‘great-greats” as a youngster might ask, would all admit that Yet the charm of. the.stilts is as insistent as ever, especially in) Perhaps it is the desire fOr it was before their time: the spring-time. quick growth which even the plant-life is feeling, which makes them so popu- lar- But often the ability to walk-on: very high stilts must be gradually acquired. _ This pair illustrated is adjustable, so that the boy or girl may learn to use them at just a slight distance from the ground, and then increase the height at pleasure. The supports | for the feet are firmly fixed in the sockets made for them, so that there is no danger of accidents from their loosening.- The sockets make half a dozen different adjustments pos- sible, and if a boy’s am- bition soars still higher, other holes may be easily made. Every Time We Wink We Give the Eye a Bath VERY few seconds we wink both our eyelids at once, although not pur- posely. If we stop winking, our eyes become uncomfortable and gradually cease to work -as they should. When the eye is open the front of it is exposed to dirt and dust and is apt to become so dry that a pain- ful stinging sensation re- sults or would do so if constant moisture were not provided to cleanse and soothe the tissues. As a matter of fact each time we wink we wash the eye. Up above each eye is a tiny water bag called the tear gland, and all the time we are awake it makes tears. When the front of the eye feels itself becoming a little too dry or dusty a commu- The foot supports are fastened securely in sockets; and atapped to Figs a ae eo "ita, enough to be - Popular Science Monthly nication is sent for a supply of moisture. The eyelid then comes down with a tear inside it to wash clean the front of- the eye. This is the most gentle and ae washing in “the world. < Fa A Wrestling Dummy Which Welcomes : gee Handling ee ILLIAM P. ARMSTRONG. of-Washington, D. C., has invented a wrestling dummy which will find favor with wrest- ling teams. At the present time there is no gymnasium apparatus | ’ available with which wrestlers - can practice. With the dummy illustrated they can go through’ many of the movements they | would assume in tackling and throwing a living opponent. The figure is shaped so that no protruding points will injure the one prac- ticing with it. The head portion of the” figure is nearly round, the arms are stubbed, and the base, although heavy, is padded and upholstered. The en- tire body consists. of AS a canvas suit. fitted over. raw ; cotton, ‘excelsior, hair or any-other yielding material. The device’is supported -on an upright board embedded securely in the base of heavy wood. . In order to throw ‘the figure to the floor the wrestler must se-- cure a hold on it and exert considerable force before it will yield. The dummy is light used at home. The figure is padded and covered with canvas so that it can be pounded vigorously without any harm being done Popular Science Monthly - It Bites Its Way Through the _ Thickest Ice _ HE natives about a small lake in lowa-— were stupefied when ice-cutting time came around to see what appeared to bea motor sled, similar to the ones they had seen pictured in the magazines, slide out _ over the glazed surface of the frozen lake, sink what appeared to be a large driving FRACK *GUARD — q = eS ee ee The saw can be raised or lowered so as to be accurately set at the proper elevation but a brand new type of ice-cutting machine, equipped with a gasoline motor, and the scream that made them look to _ their life preservers, was the shrill sound _ of the whirring saw as it bit into the ice. When they went out and looked the machine over they found, as intimated, a _ squat, rigid sled upon the deck of which a __lusty one-cylinder - gasoline engine was ~ bolted. A belt communicated the power _ to a circular saw located aft, which was _ driven at amazing speed. _ The inventor, who is John Hill, of Story _ City, Iowa, demonstrated the machine, _ showing that it could rip a straight line _ through the ice at a speed which made the _ ordinary up-and-down sawing method _ seem to stand still. By a simple arrange- _ ment the saw could be lifted off the ice or __ lowered upon it with little effort. The sawing machine is pull along at a leisurely rate, the saw cutting the ice in any direction desired. The illustration at right above shows the old method of sawing the ice by hand How Do Fish Locate Fresh-Water So Unerringly? OW salt-water fishes determine where they are, and why fresh-water fishes can always find their way into rivers is made clear by Drs. V. E. Shelford and E. B. Powers. Their studies on the resistance of salt-water fishes to the decayed and de- composed things, lead to an explanation of their habits. . It appears that herrings can sense dif- ferences in heat and cold as small as a quarter of a degree or less. They appreciate the fact that only a trace of an acid or alkali is present in water. So sensitive are herring to acids and alkalis that the scientists pro- pose that these and other fish be used to detect the chemicals in- stead of the litmus paper, which chemists use, and in the same manner that canary birds are used to discover traces of poison coal gas in mines and elsewhere. In connection with the entrance of salmon into rivers and other bodies of water, Drs. Shelford and Powers say it is evident that they find their way by virtue of the presence or absence of acids and alkalis. Fish determine the direction they must go to fresh water even when hundreds of miles out at sea and find their way to bays, harbors, and inlets when their mating season demands it, by the chemical condi- tions of the water. It is not necessary to appeal to “‘instinct’’ to explain the return of certain salmon to certain rivers or the running of herrings in certain localities. These new chemical discoveries make it all clear that smell and touch are the senses most concerned, and these are highly de- veloped in certain species. DRIVE PULLEY 70 Popular Science Monthly A carload of scrap tin which is detinned at the mill and afterward melted and sold as steel A Carload Featherbed of Scrap Tin HE two men in the picture are not reposing on a carload of hay, or ex- celsior or shavings. They are taking a noon day siesta on scrap-tin loaded at one of the big sardine-canning factories at Eastport, Maine. Tin cans are not composed entirely of tin; they are cut from giant slabs of sheet steel covered with tin. After’ the cans have been cut from the metal the scrap is loaded into cars and delivered to a de- tinning factory where the tin is chemically removed from the sheet steel. The de- tinned scrap is sent to the steel mill where it is melted into steel billets. Getting. the Most Out of the Mining Mules HE reputation of the mule is un- enviable, to say the least, and to the unthinking there is no better way to make ‘him work than by the unstinted use of the bale stick. In sion that inhuman abuse and negli- gence which result in disability or death are not in accordance with -sound business methods and common sense. The mules represent an average expenditure of about one hundred and fifty dollars each. Consideration for their comfort and health is simply a conservation of capital, according to the more modern viewpoint. ~An employee who is caught abusing or maltreating one of the animals of a certain western mine, for instance, is instantly dismissed on the theory that if he does it once he will very © probably do it again and again. Bungalow Fire Stations Are Popular in Residential Sections N residential sections the old type fire station is a blot on the landscape and a cause of annoyance to home-owners, to say nothing of the scant comfort it affords the* firemen. Modern progressive cities © are favoring buildings which conform with the character of the neighborhood’ where — the fire station is located. In business “sections brick and stone are used, and the buildings are as nearly like the average type of the locality as possible. In the ‘residential districts the bungalow type is favored. The illustration shows a station of this style in Portland, Ore., which might easily be mistaken for a. picturesque residence if it were_not. for the inconspicuous sign above the entrance. The’ firemen do their own housekeeping, and there are no cur- tains in. the neighborhood more immacu- late, no windowpanes more glistening or grounds more neatly kept. ; the mines, especially, where mules are used exclusively, humane methods -of treat- ment are generally considered impracticable. The little ani- mals are usually at the mercy of brutal and ignorant drivers and are often forced to work from morning until night without food or drink during the day. But scientific thought is reaching even the mining ee | mule, and progressive firms A fire station in Portland, Ore., which vies with any are arriving at the conclu- house in the neighborhood for attractiveness of design ‘COMPLETE power-plant supplying a home with all the electricity it needs is in reality a miniature power- ~ house like that used to supply electricity to thousands of homes. It must contain all the essential elements of such-a*power-house _ but on a smaller and simplified scale... Still, a gasoline-engine and a dynamo are not simple things. Formerly, only a skilled electrician and mechanic was. able to run his own plant without trouble. With electric-plant, however, it has finally been made practically automatic in operation and so simple that a child can operate it. One of the first things simplified was the gas-engine. It is now automatically oiled. Because it has a self-starter, it is started _ by the mere _ closing of a ® switch. The next improve- ment was the combining of _ the engine and dynamo into one apparatus. Formerly they were separate machines con- Bi aa aha > = OiL HOLE EXHAUST VALVE ’ LIGHT AND POWER WIRES PUSH ROD ADJUSTMENT UGHTAND POWER SWITCH _- f D> \ SS SSS RA Felling a Stack of Steel by Means of a Flame HE felling of this great steel stack below was accomplished by means of a single oxy- -acetylene ah as torch. : Acetylene-gas was arsed under great pressure in a steel. tank and as it slowly issued _ from the tank into the torch it ~ was ignited. As the acetylene ‘ burned in the air a great cmount of heat was devel- oped; but when oxygen was turned on from another tank, the heat then developed was many times greater. In fact, so hot was the small flame that it bit into the solid metal as if it had been so much putty. The places that were cut being carefully selected near the bottom of the stack, the huge column of steel was made to fall in a. predetermined spot. : The stack was on the old Hatdsen Street station of the Commonwealth Edison Company, in Chicago, now being dismantled to make way for a new sixty million dollar terminal. This huge steel stack was felled i in a few min- utes by the flame of an oxy-acetylene torch ae © Paul Thompson Above: Setting a tor- _ pedo net around a _ British dreadnought. The net is held out about thirty feet b HE protection ‘ of a_battle- A new application of the net which may popularize its use Protecting a Battleship Against Torpedoes Photos © Int. Film Serv. The torpedo at the instant of contact with the ‘‘catcher.” The net is connected with a shock absorber photographs show a new torpedo ship against Testing a new torpedo “catcher” at ‘catcher (the _ - its pigmy but deadly the Naval Topedo Station at Newport ventor’s word for assailant, the tor- net) which its spon- _yet_to solve. in such a way that the shock of a discharge was certain = unship them. Further- _ More, it was impossible to use them once the ship was 4 ider way. As may be ~ expected the handling and ~ fixing of a net, even during * fine weather, is no easy _ task. : ~ | Great Britain is the only _ power which has put the a. net to an exhaus- _ tive test. Our Navy has vhever required them. _ The accompanying , ya ‘ay ee woe pedo, is a problem which inventors have In the British Navy some teliance has been placed on nets held out asa sort of shield around the ship, but the results have been unsatisfactory. _ booms which held the nets out have been _ large and unwieldly and have been fixed The s. ¥ PSION HYDRAULIC CYLINDERS NET NET FASTENED TO SHIELD STEEL HINGE PLATE Details of the elaborate torpedo net operated by hydraulic cylinders. No booms are used $1 sor thinks is strong enough to protect a ship from torpedo attack. It consists of half-inch wire cables in net form on an L-shaped sliding steel frame. It is twenty-five feet from the ship’s The net defense of a ship is always divided into three different parts, namely, hung about side. the main defense, bow de- fense, and stern defense. The main defense covers the middle and most vital parts of the vessel—that is to say, the engines and magazines, and the bow and stern defenses cover the other parts of the ship. These latter, however, are used only when the ship is at anchor. When in motion the water would force the net up to- ward the surface, leaving the hull of the ship exposed. Putting Railroad Wheels on Automobiles How the automobile ‘‘gets there” when roads are bad and the railroads are the only means of locomotion WING to the high price of steel, a railroad in Montana decided to salvage the rails of an abandoned lumber and tie road connecting the station of Nahant, Montana, with the great forests thirty-five miles to the west, now protected by the Forest Reserve Act. The transfer com- pany, which handled the salvage work, found that the problem of power was the chief obstacle. The track was in poor condition. ; It could not stand the weight In the first picture above the automobile pas- senger truck on railroad wheels is shown. The wheels are of the standard railroad-track gage of a locomotive, without repairs, and in places it was almost hidden in brush. A standard two-ton truck was. purchased and equipped with a set of steel wheels with flanges for operating on rails, and then put to work. In the first month, the truck covered about three thousand three hun- dred miles. By the use of a flat car as a trailer, the truck was able to haul twelve tons of rails into Nahant each trip, making two a day. It climbed several grades as steep as seven per cent and registered an economy in operation of more than ten miles to a gallon of gasoline. An experiment of the kind was suc- cessfully made by the private owners of forest land between Hartford and the old mining town of Monte Cristo, in the northern part of the state of Washington. Their automobile - railroad traverses great areas of forest land for fully fifty miles. Steel wheels of standard gage to operate over railroad tracks solve the problem of bad roads in unimproved territory By the use of a flat car as a trailer the auto- - mobile truck was enabled to haul twelve tons of rails on one trip. It made two trips daily Popular Science Monthly A New Railway-Handcar Mowing-Machine HE railway-handcar has been converted into a rail- _ way mowing-machine. The _ three men required to operate it are able to do the work of thirty men with scythes, and when the car is mowing at its maximum speed it can cut down from two to four miles _ of weeds and brush an hour. _ When the mowing blades are _ not in operation the car can _ travel from eighteen totwenty _ miles an hour. The motive _ power is a_ six-horsepower _ gasoline engine. errand een ae me, | or... ~ — Es pam —— em ii Thomas McGee, of Madi- ~ son, South Dakota, is the in- __ventor of the machine. He has made the mowing blades vertically _ adjustable, so that they may be moved into different positions and to different _ inclinations for mowing upon level or inclined surfaces. Furthermore, the mow- ing mechanism at each side of the car is _ controlled independently, so that one _ mower may be thrown out of operation 4 while the other continues to cut. + The accompanying illustration shows q - the mowing-machine car with cutting ~ " blades raised to pass through center-guards. _ When the blades are operated they cut a _ swath five feet wide on each side of the car. After the weeds and brush have been removed another machine—the railway _ disking machine—is brought into operation in its wake. This machine has a series of ‘disks which smooth down the gravel just pevond the ends of the ties. A supply pipe connected the boiler of the engine with the pipes of the heating plant and made a whole theater comfortable A Steam Tractor Makes a Theater Audience Comfortable HAT is the cheapest and most satisfactory method of heating an opera house when a new heating plant is being installed? This was the question put to the manager of the city opera house in Carlisle, Pennsylvania. A number of performances were scheduled, the weather was stormy and cold, and the theater interior had to be made comfortable for the audiences. The manager looked about him for a means to heat his theater. Several methods were suggested, among them the utilization of a big steam tractor. This last appealed to him and he had the tractor run up an alley to the stage entrance. A supply pipe connected the boiler of the engine with the pipes of the heating plant of the theater, the pipe being run through a SS window in the rear of the stage, as shown in the accom- panying illustration. This arrangement proved satisfactory, causing the mana- ger a minimum of expense and inconvenience. It kept the heating plant working at its greatest ca- pacity and no one except those who were acquainted with the facts realized that the steam tractor sheltered against the side of the building had any part to play in making the The mac*.ne runs at from two to four miles an hour, cutting @ five-foot swath on each side of the track with the blades audience comfortable and the show successful. What’s Next in Automobiles? A gas-engine piston-ring. It prevents the breakage of the member ends and provides a metal-to-metal seal which prevents gases working past the piston Above: Not merely a ham- mock but a warm,comfort- able bed for automobile campers. The seat cush- ions placed lengthwise be- tween the tops of the seats form the mattress At left: A-hydrant for motor-busses. Drivers are supplied with disks which, when slipped into the slot, permit the hose to be at- tached and waterdrawnoff At right and below: A combination bumper and snow plow which en- ables automobiles to keep roads open in winter. Spiral springs allow for va- riation in the road surface. The plows are easily un- coupled from the bumper 84 Anew device which enables the auto- mobile to jack itself up. It is easily adjusted. Rocking it back and forth elevates the axle higher and higher To lift up the front wheels, this new jack is placed forward of the front axle, the automobile is Started forward gently and, Presto! the work is accomplished Above and in oval: A device which elim- inates the glare of electric headlights by throwing the rays from the upper half of the lamp on the road. The rays of the lower half are directed so that they add to the light deflected from the upper half At left and below: The first dental motor- car for the British troops. There are two chairs in the car and other equipment sufficient to treat four patients at once How the Automobile and Motor-Truck Y Z Y Y y 7 | | Z Y ) g GY Y E T.-C. EEE” YY While its two-wheeled At left: A motorcycle trailer was being loaded clothes closet which de- with sand from an over- livers garments without head hopper, the truck creasing or wrapping shown above saved tug- them. A dozen hangers boat hire by hooking to a hold the clothes high loaded scow and pulling enough so that bundles it along to the dock where can be placed under them it had to be unloaded Below: Illuminated fend- ers instead of headlights. The light is thrown for- ward and downward, so that it shows up the condition of Below: The “health wagon” of the Wisconsin Anti-Tuberculosis Associ- ation. It carries its own Soro ere es the roadway i 3353 mediately in front lng fled [TCL hy of the automobile y ee en = SiS Os ey Z Z | yi Y Y Z ) 7 iz y)- Z y y 7 Z Z Z | 7 Z Z y Z GE Z y Z ] Z Z vio ite Sia tae Fs d dumemaidaaiaiiiéiétiéclEu LCC ZATZQTZZUUOEEL WW 86 Above: A finger signal light which secures its current from the main headlights. The driver uses it to signal to fol- lowing vehicles when he wants to stop or turn At right: An eye- “ glass wind shield which may be ad- justed to any angle desired. It is as strong as a liner’s porthole, which it resembles somewhat At left: A vibration- proof clock encased in hard rubber. It is attached to the dashboard. A recent invention consists of a clock in a rub- ber case attached to the steering wheel Atright: The easiest riding seat a baby everhad. The bas- ket is suspended by a strap and springs attached to the rear cover rib of the car Te PE ON ONSET SE IS 87 & A protozoan, the simplest living animal organism The protozoan divided. Each one becomes two How Life Begins A wonderful motion-picture which shows how microscopic cells multiply and how butterflies and higher animals grow To photograph butterflies in the act of laying their eggs and to explain the development of the life that eventually emerges from the eggs, Mr. Stone invented the special camera and glass here shown F course you have seen on the screen those O wonderful pictures in which a budding rose unfolds itself petal by petal, swells into full bloom and then shrivels and dies—all in five minutes. How is it. thus -possible photo- graphically, to compress spring, summer and autumn into a few hundred feet of film? The pictures are obviously real—and yet how dramatic- ally unreal is the ephemeral life that flourishes and dies before your eyes! A motion-picture camera makes sixteen ex- posures per second. The resultant pictures are thrown upon the screen at the same rate. In- stead of taking sixteen pictures per second, sup- pose that one were taken every hour and suppose further that the sixteen positives, ultimately ob- tained, are run through the projecting machine in a single second. Obviously, a process. which was photographed in sixteen hours would be re- vealed on the screen in one second. Here we have the secret of the rapidly unfolding and withering rose. An automatic camera took a photograph of the flower two or three times a day, but the final film obtained was projected on the screen in a few minutes. The effect is as if a miracle were being performed before our eyes. 88 3 5 Re ee ee r = . nr & % . my FS ag % * ‘ . Stes 3 : e- Portion of the film showing divided rotozoan’s career P - a en ee Different stages in the division of the protozoan Popular Science Monthly Mr. George E. Stone, of Berkeley, California, has hit upon the idea of applying this principle to make clear the complex subject of life and the methods by which plants and animals are born, live and die. With the assistance of Dr. J. A. Long, Professor of Embryology in the University of California, a film has been prepared which not only surpasses anything that has hitherto been attempted in showing the blossoming of flowers, but which is of immense scientific importance as well. No doubt other scientific men have had the same idea. But for lack of a suitable apparatus they were unable to photograph the minute life which is seen only through the microscope. This, Mr. Stone has invented. Some of the remarkable films which he has obtained are reproduced in connection with this article. Simple Cells Merely Split in Two The simplest plant or animal is that which consists of but one cell. Hence his film starts its photographic lesson in “How Life Begins’ by showing a swarming mass of protozoans—simplest of all animals, because their bodies consist of but a single cell each. A protozoan reproduces its own kind by the simple process of splitting itself up into two parts. That fact the film drives home very clearly. A protozoan, highly magnified, is observed to constrict and divide in the middle. Each of the halves thus formed at once becomes a new one-cell creature. And each of these new creatures, in turn, splits up into new cells, until they become so numerous that at last one realizes In making motion-pictvres of microscopic life, Mr. Stone used the electric arc. The camera was driven by an electric motor controlled by the foot é ® Ses It was a three weeks’ task to take this strip of film New protozoans resulting from a division of an or- iginal protozoan 90 why it seems necessary for animals to die. This short scene (it lasts only fifty-five seconds) was most difficult to take. Three whole weeks of watchful wait- ing were required on the part of the photograph- er. He had to observe the ani- mals constantly and to be pre- pared to photo- graph the divi- sion when it oc- curred. How the Yeast Cell Reproduces Microscopic life re- produces not only by self-division but also by budding. To bring out that fact, the com- mon yeast plant, used in bread-making, was chosen by Mr. Stone as a motion-picture subject. The yeastisa one-celled plant. It reproduces by a process of budding which close- ly resembles the divi- sion which takes place in the protozoan. The yeast cells bud slowly. In order to secure a record of their growth, the photographs were made at intervals of four and one-half min- utes over a period of twelve hours. Since they are viewed at the rate of sixteen per sec- ond, the growth is wit- nessed in the short space of ten seconds. The film next ex- hibits to us the repro- ductive processes of Popular Science Monthly higher and more fami- liar plants. It shows that they reproduce their own kind either from cuttings or from seeds. A slip of gerani- Section of the film showing the devel- opment of a rat’s embryo. All life develops from cells, in the same way um was planted. One photograph was made every six hours. On the screen a The mother rat coming out of her box and picking up her progeny one by one in her mouth, dropping . them into the nest To the left is an enlargement of one of the hun- dreds of pictures made to show the development of the rat from the embryo to the living litter. Since the rat is a higher animal and the processes of life are ex- plained from the crudest to the most complex forms, this por- tion of the film is near the end growth is shown in one second which took place in four days. Most plants, how ever, develop from seeds, and the seeds, in turn, originate in the flowers of the parent plant. To bring out that fact, photographs and diagrams of the sweet-pea are present- ed to show how the pollen grains from the anthers fall on the stigma and there pro- ceed to grow and send out tubes. The tubes work their way down through the coarse tis- sues of the style until they reach an ovule. Then the whole process of fertilization is re- vealed—how the fer- tilized egg cells become peas while the pistil of the flower becomes the pod which sur- rounds and _ shelters them. Much more difficult was the problem pre- sented by the higher animals. With them life begins in a fertilized egg cell. The first ani- imal shown is the sea urchin, close relative of the starfish. On the LTR ES NIT ITN OPER by o~ The Siialicw-tail butterfly laying her creamy-white eggs on the anise The beautiful eggs of the swallow- tail butterfly as re- vealed by the film Popular Science Monthly screen, two eggs are shown, bombarded by millions of spermatozoa. The fact that the fertilization of an animal egg is fundamentally the same process as that previously witnessed in the plant, drives home the essential similarity of the reproductive processes in the animal and vegetable kingdom. In every case fertilization consists in the fusion of two specially organized cells. After fertilization, the cell resulting from the union proceeds to divide into many cells, which finally colonize into what is then an embryo. From Egg to Golden-Winged Butterfly Full of dramatic interest is that section of the film which depicts the life history of a butterfly— one of the “‘swallow-tail’”’ variety famous for the yellow and black of its body and its ‘‘eye spots’’ of red and blue. A mother swallow-tail is shown on the screen laying her beautiful creamy-white eggs on the sweet anise. Four days later—on the screen only a minute later—a small black caterpillar emerges from one of the eggs. It feeds. In order ~ to grow, it sheds its skin and emerges with a new and more beautiful one. Another period of feeding intervenes. Now it is revealed spinning a silken loop and attaching itself to a firm support. Then the marvelous process of skin-shedding is un- folded. A chrysalis has been formed. For many months this hangs motionless. Then, as the film unreels, it suddenly shows signs of life. At the end of two days—a few seconds on the screen—it bursts open and releases a limp, curious insect with crumpled wings. This is the new butterfly. So, other life processes are explained—those of the frog, the chicken, the rat. When the last foot of film has flickered past, you come away with the feeling that man himself is mysteriously linked with that simple protozoan which you saw in the beginning, and that the process of growth and development is the same in all the living universe. 91 aa ae A dramatic moment as the film unreels is that when the butterfly struggles out of the chrysalis. It has passed through many stages since the egg was laid, but now its limp wings expand and it soars away Portion of the film showing the cater- pillar stage of the butterfiy’s life The butterfly flits joyously away after having emerged from the chrysalis 92 : What Jack Frost Did with a Fountain of Running Water ACK FROST is our deftest J and daintiest architect. He builds millions of structures each year and draws other billions of patterns. The prob- lem of being original never bothers him. Each snowflake is an artistic triumph; . each frosted window-pane is differ- ent in its every detail from the countless billions which have appeared since the beginning of time. No, Jack Frost doesn’t bother about patent and copy- right laws. If he were so inclined he could secure a patent on every snowflake that falls. The accompanying illustra- tion below shows what he has done in the way of an ice cone. Next winter he will make one in the same place—and. make it so it won’t infringe on the rights of this one. The ma- terial he worked with here was a spring which gushed up into a fountain. As the ice formed, the water was raised higher and higher from pressure under- neath until the cone was formed. If it could be examined or if a cross-section of it could be obtained it would probably be found to have a hollow center, growing gradually smaller and smaller in diameter. The fact that the running water had consider- able pressure from a high fountain head and that water will find its level made it possible for Jack Frost to fashion the cone. However, the fountain isn’t so important after all. He could do equally well with a stream of water from a garden hose, if it were made to spout upward in the same manner and left long enough in that posi- tion in weather of the proper temperature. This great stalagmite of ice was formed drip by drip Popular Science Monthly An Icicle Which _ Sprouted”” Over Night ~ HO ever heard of an cle growing upside down? There was one particular icicle which was not contented with the usual order of things and accordingly decided to grow — from the bottom up. The water as it fell drop by drop— from a faucet one very cold night in Beaufort, North Car- _ olina, froze before it could travel very far on its journey. Slowly, as the water froze, the icicle grew, and when morning came the “‘sprout”’ had reached ~ a height of twenty inches. It is interesting to note that — the huge “‘icicles” of rock — which are often found in caves ~ of the mountainous districts of — the United States are formed — in a way that is very much similar to the way this icicle was formed. Underground — ? streams of water, which carry various kinds of rock in solu tion with them, frequently empty into cave at its top. The water droppin ra gradually from the roof of the cave, slowly evaporates and leaves the r in its solid form. As drop after drop falls and evaporates, a giant “‘icicle’”” i of rock is formed which is often made up of many attract- — ive colors, though — yellow, mellowinginto — brown is the most common. Somestalag- mites, as they are ~ called, when the — base rests upon the — ground, or bottom, — of the cave, take hundreds of years to form. Often they meet stalactites (sim- ilar formations with the base attached to the ceiling or high projection in a cave) and thus forma con- — tinuous column. The — Mammoth Cave in — Kentucky contains many specimens both ¥ The cone was formed gradually from circumfer- ence to center until the highest peak was reached of stalactites and ~ stalagmites. A Winter Experiment with Bulbs Growing two decidedly different hyacinths on one stem The resultant cluster will have all the characteristics of the two different bulbs including colors and single or double flowers O raise two hyacinth bulbs together so that they appear to be one plant, well devel- oped bulbs should be selected, and, in a general sense, the more distinctive these are the better. The colors of the blossoms should be as widely different as possible. It is well to make sure that the bulbs will bloom at about the same time. The best results are secured when the bulbs are started during the month of January. Cut each with a sharp knife, right down from the crown to the base, so that the side of the central shoot containing the leaves is exposed. Great care must be The bulbs are cut in half, only the half containing the central shoot being required The two halves of the bulbs used must be fitted accurately to- gether and tied securely The cut edges should be sep- arated by moss, as shown at the left. The soil should be kept moist but not too damp exercised in order that no in- jury be done to the shoot. The smaller halves of the bulbs are useless and may be thrown away. Put the two larger por- tions together so that the open ends fit easily face to face. With some twine or raffia tie the portions firmly to each other so that a single big bulb is formed. Put a little moss in between the cut edges in the manner shown. The made-up bulb may be potted, care being taken to ram the soil around it more tightly fhan usual. Moreover, a good third of the bulb should be allowed to stand up above the surface of the mold. Saving Natural Gas with Muddy Water Why. muddy water? Because the mud clogs . the gas-bearing sands up the outlets in | RFOOT VALYE © - AND STRAINER The clay and water are mixed in outside pits and then The mud effectually plugs up the gas-bearing sand without interfering with the drilling pumped into the wells. N boring for oil, work is frequently hin- dered by unexpected gas-bearing sands. Huge quantities of valuable gas are thus allowed to escape, because it is oil, not gas, which the workmen are after. The Government Bureau of Mines, noticing this waste, has recently evolved a method of reducing and practically prevent- ing it, without in any way hindering the work of boring for oil. Thus the gas is conserved for later consumption. Be- sides, it is made far less dangerous for the workmen to operaie the drilling machinery. The method makes use of so simple a remedy as muddy water—a material some- times dignified by the technical name of “‘mud-laden fluid.” It is based on the principle that a drill-bit on the end of a long cable can go up and down in fairly fluid water almost as readily as it can in a dry hole and hit the bottom of the hole just as hard. The muddy water in the well opposes the outflow of gas. Why muddy water? Because water has a ten- dency to become muddy by loosening material from the sides of the hole, causing cav- — ing and unending diffi- culties. If the water is already muddy, the solid material carried in sus- pension soaks into the gas-bearing sands as they are encountered, effect- ually plugging them up, at the same time permit- ting the drill to work on the bottom of the hole. It is little hindered by — the presence of the water. — If the gas pressure is ' great, the well can rick " nearly filled with — a muddy water, the ane of the resultant liquid — column being sufficient in most cases to stop any — outflow of gas bubbles, thus reinforcing the ef-— forts of the mud which has soaked into the ee 4 eous sands. 4 The mud-laden fluid: q is usually made up of about twenty per cent clay and the rest water. Sticky clays, such as gumbo, — are most effective. The clay and the water are mixed in outside pits and — then pumped into the well. The precise — methods by which the pumping is done — . depend upon various factors, such as — whether the well is already blowing gas or — not, whether the well is deep enough so — that a water column is sufficient to hold — back the gas pressure without external aid, — and similar considerations. In each case simple expedients are used, the desired end — being to get the muddy water into the hole ~ with as little danger of asphyxiating the workmen as possible and with as little loss — of the gas as may be. A well once sealed — up with muddy water in this fashion may ~ be opened at any later time simply by ~ pumping out the water. The gas pres- — sure will at once overcome any opposition ’ of the mud soaked into the sands. a Thus the owner of the well may keep — the gas bottled up in its natural reservoir until such time as he may find use for it. — | 4 Z A Machine Which Abuses Boxes to Find Out How Strong They Are q O determine the best kind of box construction _ for a given purpose, a machine for testing boxes is now in _ operation at the Forest Prod- _ ucts Laboratory, at Madison, _ Wisconsin. This machine was _ devised by the engineers of _ the United States Forest Ser- _vice after consulting the _ American Society for Testing ' Materials and the National _ Association of Box Manu- _ facturers. : _ As more than four and a half billion feet of !umber are _ used in making boxes every year and as many boxes are broken in transit, with injury _ to their contents, it is hoped _ toeffect a big economic saving _ by finding out through this _ machine just what are the _ best methods of box construc- tion. __ The machine has an hexago- nal drum, the sides of which Pad tages " _ measure three and a half feet. is lined with sheet steel. Piece AS bolted to the bottom form the “hazards.” Boxes filled with cans of water are placed It is then rotated. The in the drum. hazards carry the boxes part then they fall back into the | the drum. The boxes are watched carefully, and the number of falls they with- stand and the manner in _which they break are care- fully registered. As a result of these tests the way in which the boxes are nailed has been found to be very important. One more nail to each side of a box gives it much greater Strength. Proper nailing will allow a reduction in the amount of lumber used, Without decreasing the Strength of the box. Boxes ' with cleated ends are found | to be very strong. The quality of the lumber isfound | to be less important than the manner of construction. Popular Science Monthly Boxes filled with cans of water are placed in the hexagonal drum which is then rotated. The drum s of scantling way up and ower part of The point is shoved into the device which grips it so that it is extracted with a pull The results of falls are noted At Last! A Device for Extracting Rusty Pen-Points HE usual method of extracting rusted pen-points from their staffs, pull them out with the fingers, if it can possibly be done. least of several evils resulting from this is to Inky fingers are the method of procedure. Among others is the chance of cutting the flesh and adding a ruby color to the ink- marks made by the be- smeared fingers. ‘ A pen-extractor screwed to the wall or desk will serve the entire office or class- room, where such pens are used, and will do its bit toward effecting the smooth and rapid carrying out of the daily routine. The pen- point is shoved as far as possible through the door or shutter of the device, which grips it automatically. With a pull on the staff the point is extracted. A receptacle is provided into which the discarded point falls. Filling in Trenches by Machinery One man can back-fill the largest trench in the shortest possible time HE two new vehicles shown in the il- lustrations below are designed to_re- duce the cost of back-filling trenches by eliminating shovelers, horse-drawn wagons or costly overhead cableways. The smaller of the two machines is intended for working on small trenches where the material to be back-filled is near the trench. The larger apparatus is equipped with a boom and an automatic scraper on the boom cable, so that one man operating the machine is sufficient to back-fill even the very largest trenches. The special feature of the machines is that they are self-propelling and move along with the work as it progresses. The larger vehicle is equipped with caterpillar rear wheels to enable it to negotiate uneven ground. It has a low frame, with small wheels, and a low center of gravity to pre- vent it from tipping over when the boom is in use. The boom telescopes, so that it can be adjusted in length to suit the work, and is fitted to swing around to the side of the machine while still attached. Hence the vehicle can travel along streets or roads without the delay that would invariably be caused were it necessary to. dismantlé the boom each time the location of the 3 work is changed. A one-¢ylinder gasoline engine is used to propel the apparatus and to operate the boom cable. One man is sufficient to run both the machine and the scraper. The scraper is pulled from the dirt-pile to the - trench by means of a rope over the boom, : it is brought back to position for the next ; load by a second cable on the back of the scraper. a The smaller machine is similar te ‘the larger, except that it has no boom and re- — quires the services of a second man to pull | ’ the empty scraper back into position | for loading. Equipped with the caterpillar- tread the | machine can approach the very edge of a trench without causing a cave-in, or it can work in soft ground or in a plowed field - with comparative ease. It is preferred to- the larger machine for small jobs and is, of | course, less expensive. ‘on The smaller machine isintended for working on small trenches. — It is similar to the larger but has no boom for the scraper Pe ee Te ee ge Le Oe ae aI ee la ia es A one-cylinder gasoline engine is used to propel the apparatus and to operate the boom cable g which pulls the scraper to and from the trench. One man can run both machine and scraper ; 96 2 ag 2 + = = = » | q } a = rd é- : t =z 4 = e& = a 2 S& Is that Ten-Dollar Bill Good or Bad? Captain Porter of the United States Secret Service invents a machine which detects counterfeit money + a rs t di % a j : = ei Wed is wl 1 ez = 5 = 4 pee = oi w Ri if ms. <] See ee Z (aod mf i. : ‘a a ae Sa 2 i a ; 1 Et Oe ee Bi co — a sal - s ; — = Ss pat aay =t ‘ fi p - 3 fa a ; / Sp . : —~t = = SS xa = “9 1 ‘46 17 18 19 20 21 22 23 24 25 . es Bea ME SS a 2 NEWEST aid to the prevention of counterfeiting is a contrivance re- cently invented by Capt. Thomas I. Porter, head of the Chicago office of the United States Secret Service. His machine is especially intended to detect counterfeit bills or coins at the moment the possessor attempts to pass them at a bank. _ Through the aid of modern processes of _ Printing and engraving counterfeits can be made so much like originals that they defy _ ordinary inspection. A special machine is _ necessary. Captain Porter’s contrivance depends on _ the principle that a counterfeiter rarely suc- _ ceeds in making perfect original plates for his bills. Somehow or other there is always _ 4 slight distortion in some part. To the _ Casual eye the products of the counterfeiter ‘look exactly like those of Uncle Sam. But Most plate-engraving processes make use of photography at one stage or another. The images of the bills must pass through a Tens, which passage is sure to distort them. Though the distortion is slight, minute comparison with a good bill reveals the de- ‘fects. The new machine is designed to ‘make the work of comparison easy. “¥ A good bill is placed on one of the oblong metal plates and the suspected counterfeit on the other so that the various orna- ments on the two may be compared according to squares The detector consists simply of a thick wooden frame about ten inches or a foot square. On the top surface, brass edgings are provided which hold in place a large plate of glass—this being divided into squares about one-fourth of an inch apart. Several glass plates are provided, each with a different set of rulings suited to the fine- ness of the bill undergoing test. Beneath the glass plate are two thin oblong metal plates faced on their upper surfaces with blotting paper or other material having a rough surface to which a bill will readily adhere. These metal plates rest side by side beneath the glass and are provided with handles at each end extending be- yond the glass. By means of the handles the bills may be shifted around under the glass at will. In using the machine, a good bill placed on one of the oblong metal plates, and the supposed counterfeit on the other each adhering to the blotting-paper upper surface of its respective plate. The ruled glass is then placed down over the metal plates and their accompanying bills, and . 1S 98 held in place by the brass edgings at the side of the contrivance. It will be noted from the illustrations that the vertical lines on the glass are numbered serially from left to right. The hori- zontal ones are divided into two sets, each designated by similar groups of letters. The user of the device merely slides the metal plates around (using the handles projecting beyond the glass at each end) until, say, the upper left-hand corner of the good bill rests beneath the point A-1 of the cross-hatching on the glass, and the remainder of the bill is correspondingly lined up and square with the rest of the cross-hatching. Similarly he brings the upper left-hand corner of the bad bill to rest beneath the point A of the lower section of the ruling—afterward like- wise bringing the other parts of the bill into agreement with the rest of the squares. All of this has the effect of placing a good bill and a bad bill squarely before an ob- server, and because of the cross-hatching on the glass, of dividing up the surface of each bill into similar squares, each of which may be compared in detail. As is readily evident, if the bad bill is distorted in any particular, the defect will immediately become apparent under such close scrutiny as this sectionalizing into small squares makes possible. The most valuable feature about the de- vice is the fact that the two oblong blotter- faced metal plates and their accompanying good and bad bills, may individually be moved up and down and round about by means of the handles at each side and a variety of comparisons made, all without disturbing the glass itself in any way. The tests performed usually consist in com- paring the various orna- ments on a bill for ac- curacy of size and shape —the moving around be- ing a valuable feature, since the ornaments do ANNAN NN AXA Popular Science Monthly The various ornaments on the bills are compared for accuracy of size and shape. the handles at the sides to facilitate the The plates are moved around by means of comparisons Counterfeit coins are compared in the © same way as bills, only a finer screen is — necessary. Counterfeit money has to be good indeed to pass the kind of a test this machine can give it. Providing Your Pen with an Automatic Fountain F course every boy wants a fountain pen. He will buy one the very first chance he gets; but good fountain pens are rather expensive for the purse that goes with “‘knickers,’’ and an unreliable one is likely to prove such a disappointment that it is worse than none at all. However, you can add the advantages of a fountain-pen to any ordinary pen-point by a new at- tachment, made very simply of spring- brass wire. The main part of the attachment lies in two small coils which are fixed under the point of plusink. These coil ends the top of the pen. jaws so formed serve the the pen to hold the sur- _ join at the rear, while ~ those near the front of ~ the pen are turned upand back to fit tightly against Thes purpose of clasping the ~ attachment to the pen- — not always happen to fall completely within a set of squares. Spring-brass wire, bent as here shown, will convert any nib into an automatic fountain pen point and of uniformly — feeding the ink to the - point as it is needed. Paes : Salmon Fishing at the Mouth of the Columbia River _ JF a fisherman has luck when seining for _ i salmon, he generally gets a haul weigh- _ ing many tons. It is perhaps for this rea- son more than for any other that so many - launches and seining-skiffs may be seen with their nets just inside the -great _ promontory near the mouth of the Colum- _ bia River. For net-fishing for salmon— - seining, as it is called—at this fruitful spot is nearly always very dangerous. Never- _ theless, in some seasons nearly five hundred _ tons of Chinook salmon—the most valuable _ and most prized fish of the species—are ‘taken by a single crew. Individual hauls sometimes reach eighteen tons, and the _ record catch for one day has reached as _ high as fifty-two tons. _ Because of the promontory on one side _ of the fishing-grounds and Sand Island lying directly opposite the river’s mouth, _ the breakers constantly ride high. When _ the steamers of the Great Northern Pacific _ ply through the narrow grounds at a speed _ of twenty-three miles an hour, the breakers _ pushed out from their side pile so high that fishing is utterly impossible. If the launches and skiffs are caught too close in- shore to weather the breakers, there will _be little chance for them to get to safety. ' Certain conditions seem to be most favorable to the formation of high waves by _ the steamers. During an ebb tide and an __ off-shore wind, the water is piled into solid _ waves often six and eight feet high. The _ suction produced at the sides of the steam- ix. is very great, and heavy nets are _ known to have been drawn in from a _ distance of two hundred feet and finally _ destroyed by the rapidly revolving pro- pellers of the ship. Popular Science Monthly - 99 The instrument used in making the coast surveys is a telescope mounted on a port- able tripod and having a delicate spirit level Endangering Your Life for an Imaginary Line ‘ROM the mosquito-infested swamps of our lowlands to the highest peaks of our mountains and from the ice-locked northland of Alaska to the blistering sands of the tropics, the engineer in the service of the United States Coast and Geodetic Survey is facing privation and hardship for the sake of precision. He is laying a net- work cf imaginary lines upon the maps of the States that we may know just how high a given place within the national boundaries is and in just what latitude and longitude it lies. Thus, the surveyor in the accompanying photograph is establishing a line along a coast where it is necessary for him to stand in water up to his waist. He is obliged to work from this par- _ Salmon fishing at the mouth of the Columbia River is dan- : gerous. Small skiffs and launches are often capsized and =. thrown high and dry on the beach if not dashed to pieces ticular spot because it enables him to see his observation point far away on the horizon. Otherwise he could not make his measurements and estab- lish his line. However, he is taking fewer chances while he is working in the water than when he is establishing a line in a heavily wooded country. Where the land is flat and the trees of excessive height he sometimes has to work on giddy plat- forms more than a hundred feet above the ground. Freakish Accidents Your home—the most dan- gerous place AREFULLY compiled - statistics show that at present the num- ber of accidental deaths occur- ring annually in this country amount in the world nothing to do with it when it is gained. One of the most interesting facts is the mitigation of old and the rise of new hazards. This process is going on to An automobile attempted to crawl under a house which it found unexpectedly in the roadway. Two men were pinned under the front seat and the fire department had to be called upon to jack up the house in order to release them. They were not seriously hurt to about seventy-eight thousand, and more than eleven million injuries re- sult from accidents yearly. Industrial accidents have a place of their own. Large as their number is, and their increase up to a few years ago was constant, yet the problem of indus- trial accidents is under process of control. But in re- lation to the una- voidable accidents to which all men are liable no such means of preven- tion are applicable. Our streets are daily becoming more and more con- gested. Our activi- ties seem constant- . ly to increase. Men 2 rush to save a min- ute of time with oa ran into a tree. This fire truck, traveling at full speed, The truck was wrecked and two firemen were seriously injured 100 a greater or less extent in every direction. For instance, fifteen years ago bicycles were a considerable cause of accident. The automobile was unknown. To-day the bicycle has practically disappeared as a cause while the automobile has rushed from obscur- ity to the third placein importance, contributing in 1915 nearly twenty per cent of the total number of ac- cidents. Contrary to be- lief, street accidents occur oftener in the least congested areas, rather than in places where traf- fic and people are most congested and the danger more apparent. The percentage IAT Ry Samy ei “i iS ee Ce ee i ene we Re ¥ =~ Mere —-— 101 of accidents is greater in the city than in the country, and the months of June, July, August, September and March in their respective order, furnish the greatest number. Examine the claims paid by the insurance companies and you get some idea of the limit- less diversity of accidents, of serious results from trivial causes, of miraculous escape with slight injuries, of the tragic and hu- morous causes that would fill five hundred pages without a repetition. “I was asleep,” said one claimant, ‘‘and dreamed that a wild bull was rushing after me, when I kicked at the imaginary animal, striking the wall vio- lently and breaking my foot.” “While assisting a lady to board a train, the point of the umbrella which she carried under her arm, was accidentally thrust into my left eye, destroying the sight,” complains another. A third has been around the world three times and never been injured, but stepped in a bucket left on the cellar stairs and fell, breaking both his legs. “Shoveling coal ina furnace whenashot cartridge which was in the coal exploded and the charge entered his right side,” reports an accident company of one case. “Was walking in front of his house when the wheel which had come off from an automobile and rolled a block, struck him, fracturing both bones of the right leg,’’ reads another report. “Stepped on the tail of a cow which arose and threw him on his head causing con- cussion of brain.”’ It’s true, too. . “Slipped in the bathtub and fell, rupturing the spleen.” It hap- pens more fre- quently than might -be sup- sed _ “While asleep Popular Science Monthly © Int. Film Serv. Photograph taken during the Astor Cup Race, at Sheepshead Bay, New York, recently. Ruckstall, one of the contestants, is shown crawling out from under his car, which turned turtle while rounding a curve at terrific speed. He was slightly injured but his mechanician and the car were unscathed An instance of fires resulting from smut ex- plosions in grain. Much valuable machinery is destroyed in this way during harvest time in a hotel the building caught fire. In endeavoring to get out of bed, I was caught in the bedclothes and fell against a table, fracturing three ribs.” “I was chasing a rooster with some scissors to clip his wings, and fell, driving thescissorsintomyownbody.”’ Itsounds absurd, but it happened. A Port Jefferson man was electrocuted while taking a foot bath in a metallic tub. He had one foot in the tub half filled with water, when his head came in contact with an electric light fix- ture. One company paid money (after investigation) to a man who “crawled under a bed for a stock- ing;aneedlelying on the floor ran into his breast.” Accidents curring at home contribute in nor- mal years twenty- six per cent. of all accidents. Oc- A smokestack which was twice struck by lightning. The second time about half a ton of loosened brick fell through tht roof of the building he Above: A ver- tical tubular boiler used after being cracked and patched. Yes; it exploded Carelessness, Lightning and Floods When waters from a flood sewer overran a gas plant these two buried tanks heaved to the top This 150-foot flag-pole was blown over in a very high gale A locomotive speeding to make up lost time crashed through a mill near Titusville, Pa., com- pletely wrecking the plant, its stock and machin- ery, but sustaining no injury to itself except An accident caused by the treacherous broken windowpanes. No passengers were in- character of the soil, which slid down jured except from the shock of the impact, the and buried a locomotive and its track steel coaches effectually safeguarding them 102 ee ee a 6. Pee a eT a me =~ ‘Sarr fige i _ Write a Catalog of Catastrophes =a A submarine formerly used for scientific sight- seeing trips un- der sea. It was lost for years and finally found beached. Noth- ing was learned of the crew - / = a .O € Se eens “ ae ~ _—- A runaway oil car dashing over the tracks, rammed into the passenger train at left. The oil was thrown like a cloudburst over the engine How the passenger train looked a few minutes after collision with the oil car at right. One trainman and three passengers were killed A steam yacht lying at anchor was rammed by a big barge This steamer carried a load of lumber and barrels of lime. Dampness penetrated the lime barrels, causing combustion and such intense heat that the cargo of lumber was affected and a spectacular fire resulted. The barge which rammed the little Fortunately the steamer was not far steam yacht above. Engine tele- from shore and all on board were saved graph signals were misinterpreted whe What Now? Has the Ocean Broken Loose and a Steamer Lost Its Way? E have read of the boat traffic on the streets of Venice, and have seen many interesting pictures, beautiful ladies and picturesque troubadours stepping di- rectly from their doors into their waiting gondolas, but it remained for a Detroit photographer to give to the world a series of pictures of a steamer making its way through the street of a great city and of the ocean lapping the curb of a New York city street. The pictures were not bona-fide photographs, however, but were the result of a very clever and legitimate trickery, which is simplicity in itself. To secure such a result as the above, he took separate photographs of the street scene and water scene which he wished to be combined. The water scene was then so cut that when placed upon the street scene its edges registered exactly with the curb lines. The water scene was pasted upon the street scene, and a fine spotting-brush was used to cover up any defects. When a photograph was taken of the composite picture thus produced, the above effect was the result. Boys swimming about in the water made the scene still more puzzling. The idea is capa- ble of a wide variety of applications, which will only too readily suggest themselves to the photographic trickster. Popular Science Monthly The two photographs are pasted together in such a way that their edges register exactly with the curb lines Change Your Motorcycle into a Motor-Raft NY amount of sport can be gotten from a motor- raft, and for those having a motorcycle, it is a simple matter to make the trans- formation. The engine of a motorcycle is particularly adapted for such work, al- though any similar engine can, of course, be used. The raft shown in the accompanying illustrations was made by J. Dutton, a British soldier, serving in the present cam- paign in Africa. Being of a ‘mechanical turn of mind he made it during the hours when he was off duty. When his vacation came, he spent three weeks in exploring the tropical rivers. He mounted the one-cylinder engine of his motorcycle near the front of two pon- toons which he made by soldering together a number of tins in which gasoline was supplied. To two eight-foot lengths of these, he soldered a bow and a stern which he formed from other tins. The propeller- shaft is carried under the platform fastened between the tops of the pontoons, connec- tion being made with the propeller through ~ a universal-joint of the kind used on automobiles. past falls long trip. The motorcycle-raft can sustain great weight so that supplies can be carried for a long trip The raft is light and it © can be easily carried | or from one lake to another — near it. It is strong enough to carry supplies for a > form. As the photo- Popular Science Monthly Helping the Deaf Mute to Talk in the Dark N THE Court of Domestic Rela- tions, in New York City, a deaf. mute couple aired their troubles recently. The man’s complaint was that his wife quarreled incessantly and would not allow him any peace until darkness came and he could no longer see her fingers. When asked by the judge why he did not look in another direction, the man replied that the deaf mute’s desire for conversa- tion is so great that he cannot tear himself away from such communication, however unpleasant it may be. Anything is better than the silence. Here is an invention that makes it possible for deaf mutes to talk (or quarrel) right on after the lights are out. It consists of tiny electric light bulbs fitted into small rings which fit over the fingers of the deaf mute and enable him to talk in the dark. A small battery fits across the palm of the hand and is operated by means of a push- button switch convenient to the thumb. The connections extending from the finger- rings to the battery are flexible so that the fingers may bend easily to conceal the lights not in use and to reveal them as desired. A Machine Which Makes Change and Keeps the Books HAT might be described as an auto- matic bookkeeper is a new device which combines the cash register, credit register and adding machine in compact —— — graph indicates, there =- isa seriesof compart- == _The machine re- cords all credit, cash and other transactions 105 FINGER BAND Each finger is fitted with a ring containing a tiny light-bulb op- erated from the battery by a push-button close to the thumb ments set above the keyboard of the machine, each of which contains a credit customer’s account. This part of the device is built on the unit system so that it can be added to as the business expands and new accounts are opened. In a credit transaction the clerk must make a record of certain details by operat- ing the keys before the credit compartment of a customer can be unlocked. When the handle is pulled forward, this compartment is automatically locked, and a complete and permanent record is printed upon the detail strip. Provisions are made by this device to record all credit, cash and supplementary transactions. It is said to simplify and expedite the accounting system of a re- tailer who does a credit business. The machine contains five totaling devices, steel type, ribbon and detail strip to record all business. Each clerk has a number or initial corresponding to cer- tain keys to identify him in each of his transactions. Customers’ credit accounts are also indicated by certain numbered keys; this key number also serves to establish their identity. At the end of the day’s business the totals shown on the five totaling devices are transformed automatically to the detail strip and a permanent record is thus obtained of each transaction. 106 Popular Science Monthly Photo by Central News With her obsolete type of Curtiss biplane (called a “‘pusher””) Miss Law covered a distance of _ five hundred and ninety miles in nine hours, making the world sit up and take notice A New World’s Record for Continuous Flight Made by Ruth Law UTH LAW, a daring young woman of twenty-eight, has two new flying records to her credit—the American cross- country and non-stop record, and the world’s record for continuous flight for women pilots. In a two-year-old, now obsolete type of Curtiss biplane she flew from Chicago to Hornell, N. Y., a distance of five hundred and ninety miles, at the rate of one hundred and three miles an hour. She landed because her gasoline gave out. The next morning at nine o’clock she was in New York. Her actual flying time was under nine hours. It takes the fastest ex- press trains twenty hours to make the trip. Untilshemade her record achieve- ment Miss Law had never flown a greater distance cross-country than twenty-five miles. This little buckboard flyer covered ninety miles of rough country road in two hours. Note the motor-wheel attached at the rear Call This a Boy’s Toy or a Junior Runabout, As You Please HE newest thing in motor-vehicles is the speedy-looking craft in the illustra- tion. It is a light but sturdy buckboard. Motive power is furnished by a motor- wheel attached at the rear. The entire machine weighs only one. hundred and thirty-five pounds, and it will cover from eighty to ninety miles on one gallon of gasoline. The control is simple, comprising as it does merely one small thumb-lever attached to the rim of the steering- wheel. A _ clutch and foot-brake are provided, and the steering arrange- ment is the same as that of an ordinary automobile. The drive-wheel is lifted about an inch off the ground and released at will by means of the clutch. It iscranked by hand. B i 7 ; . | s Thirty cents out of every dollar spent for tires is thrown away. Why? Because automobile users do not take care of their tires T the end of 1916 about three and one-half million pleasure automobiles 4 were in use on the roads of the _ United States. During the year the owners __ of these vehicles spent about one hundred dollars each for tire maintenance. It follows that the stupendous sum of three ‘hundred and fifty million dollars is an- _nually spent on the tires of the pleasure cars alone. But much of it is squandered. Ignorance and carelessness are responsible 5 for much waste. Mileage is literally built ; “intoa tire. It is the driver’s task to obtain _ that mileage. The manufacturer has pro- _ vided for everything except human fallibility. That is why thirty per cent of the money annu- ally spent on tires, in other _ words, about one hundred _ and five million dollars— “money enough to interest enough to build half a dozen Be rcadnoushs, could be saved by the judicious use of mere air, something that costs nothing. Under-inflation is the cause of far too much 3 tire trouble. Klondike gold “Miners, enriched overnight, have been known to light cigars with hundred dollar ills and are regarded as horrible examples of reckiess prodigality. But what shall be _ of the sensible business man who throws rubber . % inch tread, ent, grippin 7. Bead, into tire rims Saving Tire-Mo Structure of a Tire 5 en Rockefeller or Car- 1. Plies of Sea Island fabric 2. Extra coating of finest rubber negie—is thrown away. between fabric layers ~ Much of that princely sum, Pte eee leer 4 Pp 7 4. 3-32 inch breaker strip of Sea Island fabric and high grade 6. % inch side wall of a rubber clincher By Waldemar Kaempffert away thirty cents out of every dollar that he spends on tires? Air Is the Secret of a Tire’s Buoyancy It is not the rubber, not the fabric of a tire that gives it remarkable cushioning properties. It is air—just air. If you doubt this, consider the old-fashioned, iron- tired, wooden buggy-wheel on the road. What happens when it strikes a small stone in the road? It rises over the stone, you say. True. But the horse had to lift the entire load, didn’t he? Whenever anything is lifted, work must be performed. Clearly, the horse was wasting power. What happens when an air- tube strikes a small stone? It is simply forced into the tire momentarily; the air in the tube has been com- pressed, or rather displaced at point of contact; the wheel did not have to be lifted. Do you understand now that the pneumatic tire owes its cushioning effect to air alone? Rubber utilized simply because it is the only substance known that is elastic, air-proof and water- proof. Para rubber ap resili- 1S built for Measure the Load on the Tires To save tire money you must understand that there is a very definite relation between the air-pressure within the tire and the Ti ws 108 load in the car. The load on the front tires as a kind of armor, and yet the tire must. and the load on the rear tires is not equal. . be very resilient—two quite incompatible Popular Science Monthly To secure the greatest service from the tires the air pressure of front and rear wheels cannot be the same. The first step, then, is to measure the load borne by front and rear wheels. That is done by running first the front wheels of a car on plat- . form scales and noting the weight, and then the rear wheels. The front tires should be inflated to about 15-18 pounds per inch of tire section, and the rear wheels to about 15-20 pounds. The inflation tables pub- lished by all tire manufac- turers apply only to unloaded cars. Cars are driven loaded, notempty. The wear on the tires of a light car, when a single extra passenger is car- ried, is anything but negligi- ble. In a small roadster, equipped with three-inch tires, that third man who always insists on riding with you, even though there is obviously no room for him, increases the load by about forty pounds per tire, which means that the tires are under- inflated by that amount so long as he is a passenger. To make a pneu- ideals. To remedy a small cut in this tire an inside patch was applied, which acted as a wedge, resulting in a blow-out To obtain elasticity and also re-— sistance to sharp gravel, the ~ tread is made very thick and the sides as thin as is con- sistent with strength and flexibility, to keep heat at a minimum and so that they may bend and recover their shape as the tire rolls along. The Action of a Tire Energy is lost in bending the rubber in the side walls, but not much, inasmuch as _ the pressure is constant and _ the air around the wheel is — continuous. Although airis — being constantly displaced, — the rapidity with which ex- — pansion succeeds compres- sion, as the tire revolves, overcomes the effect of this” work almost wholly. In the_ solid tire, work is done by the rubber, theinherent compres- sibility of the material being | — constantly tested byrepeated _ compression and expansion — and attendant heating. . A tire which is blown — up tight is not so yielding a cushion as one which is _ softer. The higher the air pressure within, the less opportunity have the sides for bending. matic which will carry its proportionate share of a load, which com- prising vehicle and pas- sengers, weighs con- siderably over a ton, for as much as ten thousand miles (the earth, mind you, is only twenty- four thousand miles in cir- cumference) is about as diffi- cult a_ technical problem as ever a manufacturer solved. The tread must act Note how badly the tread shown be- low is cut and torn from the use of chains, evidently fastened tightly to the spokes and not soon removed Hence, the temptation — is strong to let out a — little -air. The car rides more easily. But all the time the side walls bend back and forth, back and forth, — thousands and thousands. of © times. You — know what — : happenswhen — A you bend a = piece of wire — back and forth — with your fingers. | It becomes hot long before it breaks. The side walls of a To the right: A casing that is badly rim-cut or broken just above the bead. The flap be- came misplaced because the tire was improperly applied tire cannot bend without heat- _ ing the interior. _ After a time _ the rubber ce- ment that holds the in- ternal = struc- _ ture together, _ hardens; the _ layers no long- -er adhere to- ' gether; a loud __ explosion breaks _ upon the air; it "Don’t Be Afraid of ; the Sun _ Although tires are thus sensitive _ to heat, it must not be supposed that _ they are very much affected by the sun on e2 hot summer day. It is true that heat _ expands the air within a tire, and that the 3 resultant expansion manifests itself in in- _ creased air pressure. But no tire manu- _facturer makes allowances for the heat of _ the sun, simply because it is negligible in the life of a tire. At the end of a day’s run, with the thermometer over ninety _ degrees in the shade, the pressure within a tire will never increase six pounds. Beware of a Little Cut Everyone knows that sharp stones, nails ind glass may cut through the tread and _ Cause a puncture. But other causes of “Ga seen are not so self-evident. The lug J a screw-bolt, a tire-removing lever, the _ inner head edges of the casing, sand, and other hard substances which have worked _ their way into the casing are equally fruit- I causes of punctures. _ Out-and-out punctures, however, occur rarely. A tread one-half an inch thick, _ very tough, backed up by ply after ply of _ the finest and strongest Sea Island cotton Popular Science Monthly 109 Below: A tire worn off by ruts. The same condition results if a tire is run on muddy roads that have a frozen crust through which it sinks, or against the curb or the stoutest cord, is not easily pierced. It is the little cut, so insig- nificant ap- parently, that is more in- sidious, be- cause it is a less obvious danger. No cut is so small but mud, gravel and dust can be forced into it, and that dirt bores its way into the tread as “ the wheel turns over hun- dreds and hundreds of times. Soon the original cut lengthens and widens. More dirt enters. Finally, the tread is completely pierced, and the dirt begins to wedge the tread away from the inner fabric. Often “‘boils’’ appear as the visible evidence of the process of destruction. Then comes the inevitable blowout, followed by the usual arguments with the tire company. Water has the peculiar faculty of pene- trating even the minutest crevices. It is rapidly absorbed by the cotton of the tire fabric. A cut, therefore, is dangerous not simply because it may admit sand or mud, but because it will also permit water to collect. Dampness acts on the fabric of stored tires far more quickly than water on canvas wholly immersed. The fabric is broken down and the casing correspond- ingly weakened. Often tires will burst after having been stored through the winter. Much of the expense entailed by blow- cuts can be saved by treating a cut as sensibly aS you would a hand injured by a little splinter. Pick out the tacks, glass and the nails, just as you would the splinter. Wash out the injury, and then fill it with 110 cuts. Above: The result of running a tire too soft, that is, under-inflated. The waves of the tread are due to loosening one of the many excellent rubber prepara- tions supplied by tire makers and repair- men. Taking Care of the Inner Tire The inner tube is the air-container of a tire. Because it is very thin, very elastic, it must be protected by outer casing. It is evident that the casing will fail to act as an armor; that the inner tube will be cut, if pebbles and gravel work their way through an external cut. Cleanliness means tire- money saved. An inner tube must not be too large or too small. If it is too large it must fold itself to fit the confined space within the casing. The rubber is sure to crack in the creases. On the other hand, if the tube is too small, it must stretch inordinately, which means that it soon loses its liveli- ness. Tire manufacturers treat the inside of their casings with a white solution which prevents the tube from sticking to the fabric. Lubrication is always necessary. Talc, powdered mica, and soapstone should be used from time to time. But the lubricant must be applied evenly with a When wheels are out of alinement, as above, the con- dition illustrated at the right results, caused by improper adjustment of the steering apparatus or a bent knuckle At left: Fabric de- terioration and blis- tering of the tread resulting from neg- lect of two small Note the two prominent ‘‘knuck- les” or ‘* bumps” Popular Science Monthly soft rag. Dumped into the case, it will merely collect at one _ point, where it will heat up and burn the rubber of the tube. Wheel Irregularities track, unevenly tighten- lead to excessive wear on the tires. The front wheels of most cars are wider than the rear to one-half an inch. A this means wheels are out of aline- ment. The cause of wheels by three-eighths Wheels that do not ed clamping-brackets of — demountable rims, loose - hub-disks, bent axles and bent steering rods, all — variation greater than — that the. wheel irregularities is generally to be found. in a short or bent drag-link between the steering arms. Wheels can be tested at the branches of nearly every important tire manufacturer and at any garage. Since excessive wear may also be due to poorly - adjusted brake drums or unevenly clamped ‘demountable rims or bent axles and rods, do not content yourself with a mere test for parallelism. Effect of Brakes A car weighing over a ton, traveling at forty or fifty miles an hour, has about as much striking energy as a twelve-pound artillery projectile. Some disposition must be made of that energy when a car is — stopped suddenly. Tires were not made for that purpose. Apply the brakes sud- denly while your automobile is running at high speed and the wheels will lock so that the tires are scraped along the road or ~ pavement. You know what would happen — to your trousers if you were scraped along: in that way. A tread, thick as it is, can endure much, but it cannot withstand that. It will be ground off, and some of the fabric ~ Locked brakes — plies may even be broken. will not stop a car more quickly than brakes rationally applied. Carelessness in driving against curb- — stones may wear away the side walls of a — If the practice is indulged in too fre- — quently, the fabric will be exposed and the © tire. Se kay ee ee Ee destruction of the tire hastened. Injuries to the wheel and tires are by no means warranted by the slight advantage gained in point of convenience to passengers. Rim Cutting Fifteen, even ten years ago, the beads of rims could cut a soft tire. Nowadays, rims are so ingenious- ly designed that only a bat- tered section will force itself into the tire. The hooks of a clincher tire may chafe a soft tire because the hooks of the side rings curve in to grasp the bead. Under-inflation is there- fore to be avoided. - That ap- plies to all tires regardless of type. A blow will bend a rim flange and form a projection _ which only too easily digs its _ Way into the tire. Since rims " are’ made of steel they rust. Rubber and rust are enemies. _A little rubbing with emery paper and a little preservative coating will save many an expen- sive tire. thin they stones gouged tire. Popular Science Monthly Because side walls must be are vulnerable. For that reason car tracks should be avoided. The rails cut through the rubber at the edges of the tread. Cobble- never provided an ideal automobile pavement; but a quarter of a mile of cobble is preferable to a Anti-Skid Devices Above: How a tire is dented when running over a sharp stone. Just as when you break a stick across your knee, the fibers farthest from the point of contact are the first to give On the inside of a tire, large break in the fabric. This re- sulted from an accident, the wheel passing over a _ stone. Not the slightest mark or indentation on Asudden niatice: tion of the brakes Produced this Anti-skid chains and similar devices are often anecessity. Apply them tightly and forget to re- move them, and the tire will show the result in deep cuts. Rubber yields; metal does not. A dull knife will pass through cheese; and a dull chain will cut a tire. Besides, any extra weight causes additional heat, and rubber is very sensitive to heat. the outside of the case was left (note x in section showing outside). The effect is just the same as if the tire had received a series of hard blows from a big sledge hammer The rubber of a tire suffers chemical de- terioration from oil, gasoline or acids. Drop any of these liquids upon a tire and it is just as if you had dropped vitriol upon wood or iron. Wipe away the gasoline or the oil which may have been accidentally spilled upon a tire, and never allow the wheels to stand in puddles of oil on a garage floor or a roadway. Light has a strong and harmful chemical action upon rubber. 112 ak a Pe To the right is shown a tire which is worn out as it should wear out after journeying 10,000 miles; to the left a tire which has been worn away and some of the fabric material broken by skidding What ‘ Balance”’ Means in a Tire In order that you may be able to cope adequately and intelligently with the strains and stresses to which a tire is sub- jected and all the obstacles which it must overcome, the manufacturer has made the tire so that it is, what he calls, well balanced. In other words, he wants it to wear out in all parts at the same time—an ideal which he never quite attains. It would obviously be foolish to provide a tread so excellent that much of it would be left after the carcass had failed. It would be equally foolish to provide side walls which would outlast everything else. To balance a tire, experience is necessary. Defect after defect is removed as it appears. Ultimately, a tire is obtained which, if handled properly, will wear out uniformly. Remember that a tire is the most paradoxi- cal construction in the entire field of auto- mobile engineering. It seems ridiculous to use a substance which is so tender as rubber and yet, if we had no air-inflated rubber tire, there would be no modern, luxuriously comfortable automobile. What- ever its defects may be, the rubber tire is an astonishing construction. It must resist the entire air pressure to which it is sub- jected, the weight of the automobile and its load, the thrust of the motor, the reverse strain set up when the brakes are applied, the blows of thousands of pebbles and obstructions against the inner air, Popular Science Monthly and the trans- verse forces applied ing. Above all, it absorber, thereby gine and other parts of the car so that they may perform ly, protect the en- easily and safely. ‘tales that. we: hear Will the Beefsteaks of the Future Be a Product of the Sea? Ps So by the act of steer- | must act as a shock: protecting the en- | their work efficient- tire structure so that it may ride Despite all the of tire costs and-tire | repairs, let it not be ~ forgotten that auto- | mobiling» ‘as we- know it, becamé possible only: be- — cause the pneumatic — tire was invented. ONSIDERING the rapidly decreasing acerage which commerce and agri- culture allow to pasture lands together with the soaring prices of almost every kind of food, it does not require a very fertile imagination to conceive of a time when meat will be a luxury for the table of crowned heads and uncrowned capitalists, — commoner, | unless the ever-resourceful seized with a realization that three-fourths of the surface of the earth is water and prac- tically a waste as far as production of varie- ties of diet are concerned, should re-discover that the mammals of the sea are worthy of cultivation as food. It is estimated that the meat of one sixty- foot whale, for instance, is equal to that of © seventy head of cattle and tastes like choicest beefsteak in flavor, when properly — prepared. Other marine mammals which are good for food as well as for commercial purposes" are the seal, the walrus, the dugong and the sea cow. The dugong has always been prized for food by Asiatics, Africans and Australians, and the sea cow formerly found | in the waters of the Bering Sea, was so noted for the palatableness of its flesh, its” size and for its gentle fearlessness of man- that it has been almost entirely extermi-— nated through man’s greed. , 4 , r ; q 4 3 vr _ a Std Ringe: Ke Py AES | _ problem an Indiana tailor has in- vented a contrivance of as- ~ tonishing simplicity. : _ yourshoulder. A plumb- _ line is suspended from _ piece. When the lower _ advantage in such a storm. It is an arrangement by _ which the sole of a shoe may be detached E tuted without spoil- -man of shoes has _ to carry, the weight of his stock becomes _ a feature to reckon _ with. But with this _ device he need carry _ only one upper and 'Various soles, _ equipped with the _ screweye and socket _ plates as shown in the picture. The > lower branch. Lines ~ are marked onthe lower the figures on the line _ opposite which the bob the shoulder slopes is _ instantly obtained. _ trian caught out in a “soaking”’ rain; but it is really a device _) i) « p “Tr es Popuiar Science Monthly 113 The Problem of the Sloping Shoulder Making Imitation Leather from Solved with a Plumb-Line Paper Preparations AILORS admit that the sloping shoul- A GERMAN firm has succeeded in pro- der presents a problem. To solve that ducing from paper pulp an imitation ; leather, which is to all appear- ances and for specific purposes as attractive as the real article. Long-fibered paper of the necessary thickness is used as the founda- tion. This is reduced to pulp and _ tinted, glycerin being added to the coloring sub- stance to give greater flexibility to the paper. After this it is made water-proof by a treat- ment with a weak solu- tion of borax or of shellac in wood alcohol. To get the actual ap- pearance of leather, a piece of morocco or other real leather of beautiful grain is select- ed for use in making the matrices in which the _A Friend of the Traveling Shoe Salesman artificial product will be pressed. Must Have Invented This ‘The impression of the grain is made by HE illustration on the right seems to coating a cast-iron plate with shellac lique- depict the dire extremity of a pedes- fied by heat, and pressing against it the real leather which is to be the pattern of the grain. When the shellac is cold the leather is drawn off and the matrix is ready for impressing the previously prepared paper mass.. After the graining, the sheets are lacquered and varnished. Another German manufacturer has a plan for rendering the paper-leather soft and pliable. He passes it through a bath of glycerin mixed with nondry- ing oils, such as castor oil, before subject- ing it to the final wet press. There are’ othe: similar inventions, so that leather from An angle-shaped piece of steel is fitted against the upper branch of the branch is pressed down snugly against the shoulder, the bob will be displaced along the branch and by reading stops the angle at which The angle-shaped piece of steel is made to indicate the degree of the slope which might be utilized to and another substi- ing the appearance of the shoe. Where the traveling sales- many sample styles . Two sets of plates having screweyes fitted 2 be 2 to sockets are attached to the shoe, one set Pe ee y the layman also. being at the heel and the other at the toe common commodity. de may be used q Using a Phonograph and a Man-Made Hurricane And yet phono- graphs are now used to assist a player to evoke the particular mood called for by the producer Inspiring Motion-Picture Actors by Means of the Phonograph ICTURE the sweet country maid of a motion-picture studio dreaming of her lover in a far-off land. The director shouts ather: ‘Look wistful, longing, melancholy —what you will.” He bellows: ‘‘Go!” which is the signal for action. A talking- machine—yes, a real talking-machine—is started, and the strains of “I Hear You Calling Me”’ are heard. “You see,”’ says the director, ‘‘the impor- tant part that the talking-machine can be made to play in the production of a motion picture. In the course of time directors will realize that the talking-machine can play the part of ‘assistant director.’ It is certainly an invaluable aid in creating emotions. We in the studio have come to regard it as indispensable. The actor may not know the whole story of the film. It is difficult for him to come in ‘cold’, and, at a given cue, work himself into the correct emotional state for a realistic and convinc- ing portrayal. Here is where the talking- machine comes to our aid. ‘‘We'know how music enhances the effect of the motion picture as presented in the - theater. The audience does not often realize the importance of the musical accompaniment. But, omit the music, and the difference is felt ina moment. The effect that music has upon the spectator is analogous to its effect upon the actor. He responds readily to the musical stimulus.” How Motion-Picture Statues Are Made Overnight NE of the large motion-picture produc- ing companies need depend no longer on outside assistance for its statues, papier- maché figures and the various artistic accessories which make up a modern thriller. This company has a special art department with twenty-five men engaged in papier-maché and composition work. In the process of making models from clay, the first step is to provide the frame for the clay, which is molded into the desired form by hand. From this clay model a glue mold is made and into this is poured plaster of Paris. When it is dry the glue is removed, leaving the cast of the statue, goblin, or what not, finished. 114 ce uloid Melodrama to Produ ni MEN POU RING WATER ia ee EROPLANE = Pe ee je = —- ci The aeroplane propeller (at the right) produces Making Storms to Order for : Motion-Pictures ATO, the poor little rich motion-picture stars do not have to wait months until a hurricane comes their way before they _ can appear in one of those thrilling celluloid ‘thunder-storms. All they have to do is to ‘don their waterproofs and then step on the _ stage where the director has a ready-made storm waiting for them. The accompany- ing illustration reveals the secret. _ The camera-man stands ready to take the scene. At the right is an aeroplane eo - It produces a little hurricane. _ The stage-hand in the foreground is at the “Switch, ready to start the propeller at a Signal from the director. On a scaffold _ over the propeller and to the right of the set” are two men pouring water on a _ trough which leads to the ‘‘set.”’ Behind the screen at the left is an “apparatus to produce flashes of “‘lightning.”’ Here also is a man holding a string attached to the vase supported upon the pedestal in the “set.” At the signal, the propeller Tevolves, driving the rain against the foliage; the flashlight is touched off, and the man pulls the string attached to the Vase, causing it to crash to the floor, just as if a bolt of lightning had struck it. ata a hurricane, which drives the “rain” (supplied by buckets of water from above) against the foliage. Thus is a terrible motion-picture storm produced Avoiding Eye-Strain in Watching Motion-Pictures Ve persons cannot attend motion- pictures because of the annoying after-effects on the eyes. Some suffer from eye-strain and others are subject to severe headaches. The relief, in most cases, con- sists in perfectly fitted glasses. The picture may not be quite so sharp, but this is more than compensated for by the increased comfort. For persons with very sensitive eyes, a colored glass, either amber, yellow- ish green or amethyst, may afford immediate relief. Several varieties of colored glass have been put on the market recently, and there are so many shades available that some suitable color can be secured. A sub- dued light in the theater has a much less irritating effect than a dark theater where the only light is reflected from the screen. It is also advisable for those who are liable to suffer after viewing the pictures to avoid sitting in a place where it is necessary to look upward, as the additional strain be- comes very tiresome, and frequently leaves a severe headache. In the majority of cases, however, if glasses are correctly fitted to a person, he or she stands a good chance of enjoying motion-pictures without any attendant ill results. 115 A Wooden Boulevard Over the Desert Building a board road across the shifting sands of a west- ern desert to provide a thoroughfare for the automobile charm of a desert, with its great golden stretches, its silences and mir- ages, it certainly is not conducive to “‘big business’”’ except to writers of romance and to camel-breeders. In the United States a desert is simply a bad place on the route that must be traversed, and as such places mean inconvenience and delay, they would have to be covered with something having a more valuable glitter than sand to have any hold on popular regard. Between the imperial trict ard Yuma, Arizona, the sand is so fine and dry that when a handful is Wiese may be the mystical irrigation dis- plank roadway have now been oihaliense through the worst sections of this desert. This roadway, eight feet wide, with double- width turnouts every one thousand feet, consists of four-inch planks solidly spiked to stringers underneath, steel strips one . and one-half inches wide by one-fourth inch thick, one-half inch carriage bolts, and nuts and washers to unite the stringers. An overhead tramway was utilized to handle the lumber to build the roadway. Several hundred feet of trolley with triplex chain blocks were provided to pick up the completed units, built on three construc- tion tables in the lumber yard, and later —, to load them on S| the wagons __ for PEO, Sel ‘ <_ SN 07/ hauling to ~ the work. Ten-horse teams were’ often ._. Above: The kind of truck. used to haul the’ track sections from the lumber yards to their destination picked up, it trickles out of the closed fist like the grains in an hour glass. Imagine, then, the difficulty of traveling over this country in a heavy vehicle, and especially in an automobile. But the signifi- cant fact is that the state high- way runs through fifty miles of such sand. Until the California Highway Commission found a way to com- a7, , used. Each’ load contained nine units, and the average haul was seven miles. The venture has proved a complete success. A light plank road was previously used, but as the sand was constantly shifting such a road was al- most as dangerous as none at all. It was soon seen that if automobiles were to be.used the roadway must be stabilized bat the sand, it was risky for an automobile to travel over this dan- gerous route. Six miles of portable The venture has turned out successfully, Heavy loads drawn by any number of teams, as well as automo- biles may now cross the desert with comparative ease 116 ere ee eo Sa er any ic The Versatility of a Pocket Comb It rivals an acrobat in the number of things it can do _ As a toilet accessory the comb takes the place of a nail file and an orange wood stick for cleaning the nails. Above: No need to hunt around for a buttonhook if this comb is in your vest pocket. It is provided with a hooked end which will answer the purpose to perfection. It will also open the beer bottle or the envelope with equal ease NDER the ingenious care of an in- | ventor the ordinary pocket comb has developed into a combination tool with nine known uses and any number of unknown ones. It can open bottles and letters, button your shoes, measure and rule lines, clean your fingernails and file them, turn on the automobile lights, take the place of a compass, and finally, comb your hair just as well as it ever did before its nine-sided usefulness was discovered. The inventor is F. O. von Tobel, of New York. When the tool is used as a compass one end is attached to a board and a pencil is inserted in the buttonhook end. The pencil is then moved and circles are drawn. The tool is marked off in a scale six inches long. The nail file is directly above the teeth, on the under side of the scale. iI In the center picture it is shown used as a six-inch rule On the left is a photograph of the inventor, F. O. von Tobel, showing that the ver- satility of the comb has not robbed it of its original hair- smoothing ability. Other uses for the comb are numerous and easily discoverable by the owner of the treasure Scrubbing Brushes by the Mile for Cleaning Locomotives A So six-ton industrial locomotives of Western railroad often come in to the inspectors for repairs and a general cleaning. To get the rough grease knoc ked off, a novel scheme has been devised. A side track about four hundred feet long has been unused for a long time, and on this there has sprung up growth of woody stalked weeds. When the engine is run slowly and forth over this natural tooth-brush the stalks slap around among the rods like long withes. Wind and rain up and restore the damaged brush and ne weeds are always growing. Thus, while conserving natural resources in weeds the railroad is also conservirg overalls. a dense } DAC k soon ciean ~ Climbing Out of a Mud Hole The automobile may use its own engine power. to operate a winch A worm and gear is first connected with the mo- tor crank-shaft to wind a cable on a drum lo- cated in front of the radiator. Then the free end of the cable is at- tached to a stake or tree and ’the car pulls itself out with little effort NY automobile which runs its nose into a mud-hole and which has no special means of pulling itself out is in a sorry plight indeed. But the automo- biles equipped with the devices shown in the accompanying illustrations have nothing to fear from the worst of holes. Each of the appliances pro- vides a simple means for getting the automobiles to “‘grip,’’ but one of them is for attaching to trees and the like, while the other is for marshy places where there are no trees. In the one case, a worm-gear is fitted between ball-bearings on the crank-shaft. This device is adapt- able for all makes of automobiles and also for motor-trucks as a hoist in loading. When not in use the worm is taken out and stored in the tool box, leaving the automobile front free and unmarred this is another gear which is rigidly attached to a drum-shaft mounted across the front of the automobile. The gears are made in a reducing ratio, so that, when a cable is attached to a tree and wound up on the drum, enough pull is exerted to drag the automobile clear. This method is very much like that used in warping ships into a side ~ berth. The other ap- pliance uses two | iron side-bars, jointed at the middle and aeross which chain- rungs are at- tached. One such “ladder” is forced under each driv- ing-wheel, the power is turned on and the car Meshing with The ladder is thrust under the rear wheel that is mired, clamping the tire and making a track 118 climbs out. Making the Automobile Do the Chores How the modern farmer dispenses with numerous farm-hands Fa } 3 + ‘ ® At right: The motor Above: The auto- > treadmill, which mobile is backed up cs consists of a wood to the treadmill and framework, two the motor is started, driving pulleys, a belt pulley and a pivoted V- shaved metal framework NOVEL device called a motor treadmill has just been the power being transmitted to the driving pulleys through friction the V-frameismoved away from the car and the two arms turned about put on the market by a New their pivots and raised so England manufacturer. It makes it that the rear wheels are lifted possible for the power of any automobile to clear off the ground. As the jack is be utilized for running a cordwood-saw, screwed out further, the tires are brought threshing- machine, cider-press, cream- up against the driving-pulleys, so that the separator or butter-making machine. former are slightly depressed at the points The device is portable and can be carried of contact on the driving-pulleys, thus by one man. It consists of a wood frame- giving sufficient traction to prevent the work or base, as shown in the accompany- tires from slipping. The automobile-motor ing illustrations, two driving-pulleys and a_ is then started, the power being trans- belt-pulley carried on the same shaft, anda _ mitted to the driving-pulley shaft through pivoted V-shaped metal frame operated by friction between the revolving rear wheels an ordinary screw-jack. The wide end of and the pulleys. The wood saw or other the V-frame is supported on two flat arms machine is then driven off the pulley-shaft pivoted to the wood base. These arms are by means of a belt in the usual manner of provided with two curved lugs at theirends operation. to slip under the automobile’s rear axle- No changes are required on the car for housing. The sharp end of the V-shaped use with the device and any make of car frame is slightly flattened to take the head can be employed, the differences in tire of the screw-jack, the other end of which diameters being taken care of by screwing is stationary against a wood block bolted _ the jack in or out as required. to one of the members of the wood base. In this way the automobile goes up still The automobile is backed up to the tread- another notch in importance on the farm. mill, so that the rear wheels are square The farmer is no longer entirely dependent with the two driving-pulleys, the curved upon more or less unreliable “hands” and | lugs on the V-frame arms being beneath the work is doubtless done better and in | the rear axle. As the jack is screwed out, less time than by the old method. 119 120 Why Wheels Run Backward on the Motion Picture Screen HEN the moving-picture camera takes a picture the film is not exposed continuously. Instead it is uncovered and then covered again in very rapid succession by a black disk edged with a circle of holes which are swiftly rotated o across the front of the lens. In A this way a series of picturesis taken which represents the successive movements of the subject that is photographed. But because of this very fact, the speed at which an object appears to rotate when the developed film is projected on the screen is very seldom the speed at which it actually rotated. Take, for instance, a four-spoked wheel, such as shown in the illustration, where.the wheel rotates at a speed such that after one picture of the film is exposed, the spoke A has turned around just enough to show A at the position of B when the next pic- ture is exposed. It is evident that in a The speed of rotation of the wheels may be such as to make it appear to stand still as in the top row, or even to be running backward as in the bottom row Popular Science Monthly. - case of this kind, if the spoke and the camera keep turning at constant speeds, when the spoke is projected on the screen it will appear to be standing perfectly still. Again, the wheels on fast moving cars often appear as if they were moving backward while the car is going for- ‘ ward. This would in the bottom row of the drawings, ing so fast when it was photographed, that during the interval between one exposure and the next, the wheel revolved all the way around from A to B. When the next exposure was made the spoke appeared at C, and so on. When this film is run off and projected on the screen, the spoke will seem to run backward. - No matter how many spokes there are on the wheel it is evident that the effect on each one will be the same, and the ntire wheel will appear to turn backward at the same speed as that of each spoke. It is merely an optical illusion. F you are a motorcyclist, if you have devised simple ways of making repairs, if you have improved your machine in any way, this will interest you. The PopuLar ScrENCE MONTHLY offers a first prize of $25, a second prize of $15 and a third prize of $10 for articles in which motorcyclists will describe and illustrate the methods which they have successfully employed for overcoming trouble, for making quick repairs by the road- side or more difficult repairs in the shop, or for making attachments whereby the use of the motorcycle has been broadened. The three prizes will be awarded by the editors of the PopULAR SCIENCE MONTHLY in the order of merit. What is more, even though your article may not win a prize, the editors may buy it at the usual rates, just because it is so good. There are no limitations to this prize offer. We don’t care for fine phrasing, but we do care for good mechanical ideas. Rough pencil draw- Money Prizes for Motorcyclists Send In Your Kinks ings or photographs will do for illustrations. The following conditions are to be observed: () ces must be written on one side of the sheet only. (2) Write your name and address in the upper right- hand corner of the first sheet. (3) Enclose postage for the return of the manuscript. (4) Don’t send in articles on ideas which have already been published. (5) Don’t send paper ideas—things that you haven’t actually done yourself. (6) Address the envelopes containing articles to “MOTORCYCLE CONTEST EDITOR” PoPpuLAR SCIENCE MONTHLY 239 Fourth Ave., New York City The contest will close on December 31st, 1916. The money for the prizes will be paid promptly after the awards have been made. happen if the. spoke A, shown had been revolv-. ea a a ee a ee a re eee | ~~ - edanelectric- green out- and adjusted “screweyes Za A Small Backyard Searchlight Operated from a Window N most suburban towns the houses are well lighted in front by street lights and porch lights, but usually the rear is dark and in shadow. It frequently occurs that strangers and tramps prowl around—look- ing for a place to sleep and sometimes look- ing for an occasional chicken. They may _ even go prospecting to see how easily a house or barn can be broken into. A small but efficient searchlight can be very cheaply _ made—provided one has electricity on the premises. A small wooden bracket with a base 2 in. wide and 1 in. thick having a quadrant - bolted at the _ end is fasten- _ ed to the side _ of thewindow _ as shown. On this is fasten- light socket with a metal reflector painted white inside and side. This is connected as shown by means of and a cord, and it is so ar- -Tanged that _ when the lever is pushed forward the light turns to the left, and when drawn backward itswings to the right. The current is turned on from the inside by a key socket. If de- sired the cords may be brought inside and the lever so arranged that instead of pushing forward and backward it is thrown to the right or left, to operate the light. The bracket can be tilted downward if the light is set high on the house, so that the The swinging of the electric lamp directs the trays to every part of the yard within its scope s TFOR PRACTICAL WORKERS light rays will sweep the entire ground. A 45-watt lamp will throw sufficient light 100 or more feet. The quadrant is the only thing that needs particular construction and it is best made of three pieces of 14-in. board in the shape of the letter D. Two are the same size, about Io in. long on the base of the arc and 6 in. the narrow way. The third piece is of the same shape but about 14-in. smaller all around. These should be placed with the small piece be- tween the two larger pieces so as to form a groove for the cord. There should be but one staple fastening the cord in the center of the outside curved part. The arrange- ment pictured will sweep through an arc of 180 deg., but if the bracket is placed ona corner, it can be made to sweep two sides of the house or through an arcof270deg. by simply crossing the cords and widening the distance be- tween screw- eyes. If the elec- tric wire is given enough play, that is, if it is left Swinging with one attachment near the house, there will be no fear of loosening the connections.—RONALD F. RIBLET. A Mixture for Cleaning the Lighter Colors of Paint CLEANER for white paint, linoleum and parquetry floors may be made as follows: Boil together % oz. of white soap in % pt. of water. Add ¥% pt. of turpentine to the soap and water, thoroughly stirring it. 121 122 Paper Funnel for Use in Place of a Grease-Gun HEN the motorist is in need of a grease-gun and one of the regular instruments is not at hand, a A paper cone asa rubsiteate for a grease-gun for forcing grease into gear-casings of an automobile good substitute may be made of a paper funnel. Simply roll up a piece of tough paper—heavy wrapping paper will do—into a cone, fill with grease, turn over the upper ‘end and begin to roll. It is like squeezing preparations from a soft metal tube of the variety in which pastes and medicated vaseline are sold, the grease being forced out through the smaller end and into the casing.—R. F. PoHLe. A Heat Regulating Device for the Furnace O have the house warm and com- fortable when you get up, be sure. to bank the fire at night. This is made easy by seeing that there is a good bed of coals in the fire box before retiring. Throw on a few shovels of coal, enough to last far into the morning, and do not entirely cover up all the live coals. Leave a spot the size of your two hands, burn- ing brightly. Now on top of the fresh coal apply a coat of ashes. This is the method by which night firemen hold the heat in large buildings and .are able to leave it, knowing the heat will be re- tained and that it will be easy to quickly get the normal temperature again. Pull up the check draft, close all others, and set an alarm clock for the time you wish to start up the fire, wind- ing it only twice around, and placing it on any convenient box or stand near Popular Science Monthly the chain-holder. Transfer the ring from the usual hook to the winder of the alarm clock, hooking it just over the corner of the winder, so that when the alarm starts the hook slides off and closes the check draft. The fire will start, and by the time you get up the room will be warm. If you want to get up at 6 o’clock, set the alarm at 5. If the alarm annoys any one, it can be muffled. Before leaving for the office, rake off the top crust of the ashes, removing all clinkers; see that the draft is open long enough to insure a fresh béd of live coals, and _ apply coal sufficient to keep the fire until noon. While the lower draft is open, remove ashes, sprinkling them as they are removed to keep the dust from sifting to the pe: rooms.—WILL CHAPEL. A Key Indicator to Tell When a Door is Locked HIS device is fitted to a cere in order to indicate whether a door has been locked or not. Within the key is fitted a small cylindrical metal piece M which can rotate inside. Its upper end has a screw-thread S. This piece works in the small threaded hole H, and can project out at the top. At the bot- tom is a slotted part A, which lies well within the key-bar- rel. On the other fy hand, the lock com- th monly carries a small 4e-A rod that fits into the key-barrel when the key is inserted in the keyhole, in order to guide the key. All that is needed is to file a square end on the rod A so that when the key is inserted in the lock the square end of the rod acts as a screwdriver on the cylinder within the key-barrel. Supposing that the key is given two turns, as is usual with safety locks, the screwing action causes the small tip to rise out of the hole H and project above the key at 7, where it can be felt with the finger, showing that the key has been used in the lock. On un- locking the door the tip immediately dis- appears inside.—F. P. MANN. If the door is locked a projection is felt Puzzling ‘Tricks with Paper If you would like to indulge in some mental gymnastics, just try this with a slip of paper has two faces or surfaces and four Can you fold such a piece, say I in. wide and 12 in. long, so that it will have only one surface and one edge? At first thought it seems to be an impossibility. Yet the solution of the problem is easy and leads up to A RECTANGULAR piece of paper edges. Take a second strip of paper, place it flat on the table, give one end a half turn and paste the two ends together. A twisted ring or band will be the result. How many surfaces has it? Begin at some marked point and follow the surface. Soon you will return to the starting point, having gone over the Various ways of cutting and pasting up a piece of paper to reduce the num- ber of surfaces and edges and to form links of a chain fastened together an interesting and fascinating study of paper folding and cutting. Y As a preliminary exercise overlap the two ends of a strip of paper and paste them together to form a cylindrical surface similar to a napkin ring. It has two surfaces now, an inner and an outer, but only two edges in place of four as in the first place. If the ring be cut in two pieces, lengthwise of the paper, two narrow and similar rings will be formed, each having the same circum- ference as the original. I 923 ~t It has but one surface. In a similar manner trace your way around the edge, and you will astonished to find that it has one continuous edge. The problem is solved. Experiment with this twisted ring still further and see what remarkabl results you can obtain. With a pair ol scissors cut this ring in two parts as you did the plain ring, and, astonishing to relate, the result will be not two but, instead, one ring having twice the circumference of the original.- From entire surface. ose rings ? 124 Popular Science Monthly this you would probably jump to. the conclusion that if this larger ring should again be bisected lengthwise a single ring with circumference again doubled would be formed. Attempt to prove your prediction and you. will discover that two rings with the same circumference as the bisected ring will be formed and these two rings will be doubly linked together. Why were the results so dissimilar? This is the explanation. The original paper was twisted one half a turn before the ends were pasted together. After the ring was bisected and the larger ring had been formed, a careful examination of it would have shown that the effect was the same as though it had been formed from a strip one end of which had been given two complete revolutions before being pasted to the other end. This accounts for the difference in the results. At this point you will begin to wonder what the results would be if the ring should be divided into three parts instead of two, or what difference it would make if the paper should be given two or three or four half turns. Also you will probably be convinced that it would be useless to predict results and that only by original investigation would you be able to arrive at correct con- clusions. Here are a few of the cases which you might investigate. Prepare another ring by twisting the paper one half turn, and separate it lengthwise into three parts of approxi- mately equal width. The result will be two rings linked together, one having thesame circumference as the original, the other having twice that circumference. The next step would probably be to form a ring by twisting the strip two half turns or one complete revolution. This ring, you will find, has two surfaces and two edges. Bisecting it will give two rings linked together. Bisecting each of the two will give a total of four rings arranged in two pairs, the pairs being linked together and each individual also being linked to its mate. A ring formed with three half turns will, upon being bisected, form a single ring with the circumference doubled, but in the ring there will be tied a simple knot. Bisecting again will give two rings, with the same circumference as at first, knotted as the parent ring and doubly linked together. In a similar manner the experiments may be continued almost indefinitely until the rings become so complicated that they cannot be handled success- fully. If a strip of paper is to be twisted several times in forming a ring, a long piece should be used, and if the ring is to be cut into several parts the width must be increased accordingly. When a ring is to be re-bisected it is advisable to mark each half with a pencil in order to help in studying out the relations. Where several rings are linked or knotted together it is some- times necessary to repeat the experiment several times, first tearing off certain rings next other rings before the com- plicated results can be understood. In general it will be found that with one, three, five or any odd number of half turns the rings will have one surface and one edge. When bisected they will formonering with circumference doubled, and, beginning with the third half turn, the ring will be tied in a knot the com- plexity of which increases with the num- ber of half turns. If these rings are again bisected a pair will be formed having the same shape and circumference as the original and, in addition, each will be linked to the other: 2 With two, four or any even number of half turns the original rings will have two surfaces and two edges. Upon being bisected two rings will be formed and they will be linked together in an increasingly complicated manner as the number of half turns increases. A second bisection will yield two pairs of rings, each pair having the same cir- cumference and arrangement as the parent ring and, in addition, each ring being linked to its mate. The trisection of the rings also yields interesting results and opens up new possibilities. To begin with, the manner of cutting into three parts rings formed with an odd number of half turns is different from that used with rings of an even number. The former, it will be remembered, have but one edge. Hence, to trisect such a ring, begin by cutting off a strip one third the width of the original. Continuing the cut, you will make two complete revolutions, finally coming back to the starting point, and the paper will apparently form a con- tinuous ring. Upon unfolding it you will find two rings linked together, one Bit tek eal Popular Science Monthly 125 having twice the circumference of the other. But the rings formed with an even number of half turns are trisected just as you would trisect any rectangular piece of paper lengthwise. These rings have two edges. Hence, to trisect, cut off one third of the ring parallel to one edge and then another third. On each cut you will make one revolution of the ring, the shears returning to the starting point. The resulting rings, as far as I have investigated them, will be three in number, each linked to its two mates, the complexity increasing as usual with the number of half turns in the original ring. Bo continue further with this descrip- tion would be monotonous. As in any experiment, popular interest centers in the performance itself, so, should you merely read this and pass on you will find it scarcely worth your while. Get a pair of scissors, some wrapping paper, a jar of library paste and try a few of the suggested cases. Start the children on it for a rainy day amusement. Give it to the boy who is wrestling with the theorems of geometry. Perhaps he would become interested in tabulating results and could be induced to give a talk before his class, illustrated by cutting some of the simplest forms. As a means of entertainment or instruction for young or old these experiments are worth while and, once started, they have the merit of possessing a peculiar fascin- ation that invites and encourages original investigation. —F. E. Tuck. Molding Hamburger Steak with a Can-Cover AMBURGER steak, shaped into balls with the hands, nevercomes to the table in uni- form sizes, and i there is more than a gambler’s chance that the hands of the cook who does the molding may not be absolutely clean. Both of these objec- tions are obviated in the use of a Ham- burger-steak cutter made from a can- cover and fitted with a wooden handle— a piece of sheet metal is fastened in the center to strengthen it. A dough-cutter used by bakers in preparing biscuits will also serve the purpose. Holder for Steel Wool to Protect the Hands NE of the objections to using steel wool for cleaning kitchen utensils, such as the bottoms of saucepans, is that particles of the wool are liable to become imbedded in the fingers; but if it is enclosed in a fairly stiff cardboard The wool is enclosed in a case so that it will-not injure the hands tube, not only will this. objection be overcome but a great saving of the wool will result. An empty 12-gage shell may be used and filled tight with the wool. This will be found to be a great improvement over holding the wool in the bare hands. The cap and anvil should be driven out from the head of the shell“and tapped for a \4-in. screw with a knurled head. The opposite end of the screw is then fitted with a plunger so that the wool may be pushed out as it is used or rubbed away. A larger tube with a wood end carrying a screw and plunger could be used to advantage. A Quick Hardener for Patching Holes in Castings O fill up holes in castings ordinary filler is not very satisfactory on account of the long time it takes to dry. Sealing or battery wax will be found very good for filling up holes in castings where no strain comes. The wax should be melted into the hole, from the cake, by means of the ordinary soldering iron. The wax hardens immediately and the filler is then applied over it as on the rest of the casting. 126 Automobile Luggage-Carrier. for. the Running Board ‘OME of the latest models of automo- biles do not permit of a luggage-carrier at the rear of the car, and most of the ready- made carriers designed to be used else- The strips of poplar with angle-iron attach- ments for luggage - carrier on running board where on a car are expensive accessories; but the one shown in the illustration is of simple design and construction and is to be attached to the running board. The materials needed for this carrier are 3 pieces of tire-steel, or bar-steel, about 14 in. thick, 17 in. long and 114 in. wide; also 2 pieces of the same thickness 34-in. wide as long as the running board. The steel is inexpensive and it costs little to have it bent. One strip of poplar wood as long as the running board, 21% in. wide and 7% in. thick; a few screws, rivets and bolts to hold the parts together and % pt. of paint will be required. The work necessary on the carrier is the drilling of the 24 holes in the steel strips, 2 in the vertical section of each angle-piece and 3 in each of the lengthwise pieces to correspond, the latter being riveted to the former. Four holes are also drilled in the horizontal section of each steel angle, 2 of them countersunk for screws to which the angles are fastened to the poplar strips, and 2 through which 14-in. stove bolts are passed through the poplar strips and into holes in the running board. The holes in the latter may be new ones or those already bored for other purposes. On the undersides of the poplar strips cut out 4 spaces 2 in. wide for the straps to pass through for holding the luggage. The measurements for this carrier should be carefully obtained by finding the exact Popular Science Monthly distance from the inside edge of one of the holes in the running board to the outside edge of the opposite hole, giving the dis- tance from center to center of the holes, There are usually two of these holes at each end of the running board, out of which the bolts must be taken if these holes — are to be used instead of boring new ones. Handy Receptacle for Small Screws and Brads N a block 15 in. long, 8 in. wide and 2 in. thick bore 2 rows of holes, 4 holes to the row, to a depth of 134 in. If it is desired to have these holes of curved or concave bottom like the old-fashioned money-till, take the piece to a planing mill where they have bits especially for this purpose. A hinged cover should be put on the block with some kind of clasp to keep it securely fastened down when not in use. Eight sizes of brads or small screws may be arranged in this size block as desired. — Blocks may be made larger or smaller according to the needs. The convenience of this receptacle is obvious. A License-Tag Holder for the Front Axle of an Automobile N states where there is no legal restric- tion on the height of the front license-tag for an automobile the front axle makes a good place to fasten it, and a good holder for the purpose is illustrated. It is simple in design, may be applied to any I-beam front axle, accommodates any length of tag and allows it to be easily removed and re- placed when necessary. It consists of a steel bracket, bent as shown and secured to the axle with a U-bolt. Fastened across the lower part of this bracket is a piece of A bracket to hold a front license tag for an automobile rigidly and without rattle sheet steel bent up to form a socket for the tag. A clip-and-spring is secured to the upper end of the bracket and when the tag is held down tight in place with this clip the holder for the tag will not be liable to rattle —W. Burr BENNETT. The Making of Photographic Silhouettes HE quaint portraits which our great- grandparents knew and delighted in ” a fashion. But a form of photography showing “shadow photographs” which has recently attracted attention is in many 3 respects a revival of the old-time art. The _ old-fashioned silhouettes were cut out, of per with scissors, and mounted upon a ‘pie card, or in some other appropriate pray. Certain ! Batinine or ketching. for much in- herent skill mn the part of the work- er. A little patience, plus a “modicum of common sense, will soon be rewarded by ‘charmingly successful re- ‘sults. Then, too, the pictures can be secured quickly as — negatives, and any number of copies can be rendered avail- able subsequently by print- |). ing out, developing and 7 fixing. Thus, at the time when the portrait is taken, the operator is free to con- ‘centrate his undivided attention upon the ‘sitter. _ Shadow or silhouette photographs may be taken either at night or by day. At ‘ight, all that is needed is a semi-trans- Parent screen, which can be made from an old linen sheet, or even from paper, sup- Ported upon a wood framework. For eral purposes the screen should be ite, or nearly so, although on occasion a a good effect may be gained by employing a screen of neutral tint, or one in which transmitted light reveals a certain graining Or irregularity of substance. In other words, the background of the finished models Popular Science Monthly Silhouette photographs of still life and of living may be made 127 picture need not always be dead white, but may be varied in tone to suit the subject. The screen is supported vertically, and the sitter or subject is placed before it. The outline or profile must be very sharply focused; and for this purpose a fairly strong and steady light is needed. But as soon as the focusing is complete, this light must be extinguished. The exposure is then made by burning magnesium ribbon, or a flash lamp, behind the screen. If magnesium ribbon is used, about 1 ft. of it should be burnt, the aperture of the lens be- ing left wide open. On the whole the shadow photographs may be made more satisfactori- ly by day be- cause artifi- cial light can then be dispensed with from start to finish, while focusing becomes much easier, and can be prolonged until the operator has found, by ex- periment, the exact position in which his. subject shows to greatest advantage. A window having a single pane of glass not less than 2 ft. by 2% ft. should be chosen. This must not be too high above the floor; if possible it should face north, although this is not essential. To the window-frame ascreen of linen or paper may be fixed with tacks or pins. Any transverse light may be shut out by means of blinds or screens. When this has been done, everything will be in readiness. If the day is clear and the light brilliant, a snapshot will be possible; and when children or animals are sitting, this is a great advantage. In dull weather, an exposure of several seconds may be necessary. Everything depends upon the density of the screen that is used. Every effort should be made to secure vigorous outlines, although all avoidable hardness should be eliminated. Remember 128 that we are working in outlines almost exclusively, although occasionally some suggestion of translucency may be intro- duced with good effect. Excellent ‘‘still life’’ studies may be made from flowers and foliage arranged in clear, cut-glass bowls or vases. Obviously, there is a wide choice of subjects, but heavily opaque objects, without beauty of outline to recommend them, should be strictly avoided. The question of printing out these shadow photographs effectively must be left to personal decision. Sensitized papers are obtainable nowadays varities of tint and surface-texture that the most exacting requirements can usually be met. If the object in view is a close imita- tion of a real silhouette, it may be gained by using a smooth-surface bromide paper which gives strongly contrasted black and white effects —PERCY COLLINS. To Sharpen Skate-Runners with a File HE following is a good way to sharpen steel skates having soft runners. Take two pieces of soft wood, about 31% in. long and I in. square and fasten them securely I in. apart on a workbench or table as shown. Secure another piece 10 in. long, 3 in. wide and 1 in. thick, to the bench-top about 6 in. from the first pieces. Clamp the eskates to these cleats the same as you would on the soles of the shoes, and _ Clamping skates to a bench-top to hold \" them securely for filing the runner surfaces sharpen them with a to-in. file. File in one direction only, to keep from spoiling the file-teeth. This method is quick, and a much better edge can be obtained by it than by grinding —GEORGE WASSERBERGER. in sO many . Popular Science Monthly Repairing the Torque-Rod Support on an Automobile HE drawing illustrates how the forward | end of an automobile torque-rod is supported. Trouble was experienced at this point on a rather low-priced car, and after examination it was found that the parts were badly worn. The plungers A, placed on both sides of the ball-end of the radius-rod, were case- hardened to avoid being worn quickly from the ac- tion of the ball-end. The support-casing, however, being compara- ened plungers, more rapidly. Bushing the sliding parts of a torque-rod of the trouble. To eliminate entire assembly was removed from the car | and the casing rebored toa somewhat larger — diameter. To allow for this increase, bronze bushings were pressed over the plungers as shown. This repair eliminated the trouble, and gave the added advantage of causing the wear to be carried by the Repairing Molded Rubber Goods __ with Quick-Cure Cement 4 HE quick-cure vulcanizing cement is” ‘excellently adapted for repairing molded goods and other rubber articles which would not stand prolonged exposure ~ to the heat of vulcanization. Hot-water bottles, rubber boots, bands on date ; bushings, which could be readily and cheaply replaced.—ApDoLPH KLEIN. a was mats of cast-iron. This | tively softer than the hard-— woreagreatdeal © Thus an unnec- | essary clearance between the plungers and casing © was made which was found | to be }gin.at some points, © and this was the cause it the 2 ‘ , , 3 stamps, etc:, are examples of articles that can be repaired with this cement. A Ground Color for Applying Mahogany Stain ISSOLVE permanganate of potash in sufficient water to make a rich crimson shade. Any kind of white wood may be painted with this solution. When dry, apply the mahogany stain and finish in the usual manner. pa Indian y Snow-Shoe . And how to make it : | lmanTaylor as the extra crossbar and upcurved frame make a very stiff snow-shoe, all curved models are harder on the feet than the flat shoes. To make a more springy shoe, NOW-SHOES are made in a large the frame may be made quite flat. The variety of shapes. The particular proper names of the different parts of a style described here is the form made snow-shoe are given in Fig. 2. and almost exclusively used by the Cree Tr cuss ipa acid iali Di iaiiil _ Indians of Canada. As shown in Fig. 1, The Frame Construction _ the shape is some- The best material what longer and the for the frame is width narrower straight-grained than the common ash. For the aver- _ Eastern or Algon- age boy a snow- _ quin shoe. In fact, . shoe 40 in. long and the model used is c= 10 in. wide will be 60 in. long and FIG found the most use- I2in. wide. As the ful. The average frame is made in two pieces, FRAME: man will find the 60-in. _ fastened together at toe LANYAR — by 12-in. wide model _ and heel, this type of thoroughly satisfactory. _ snow-shoe is the easiest of — END FLUNG The complete dimensions all forms for the amateur | for a good frame are given _ to make, because the one- BHA roe- in Fig. 3, and a study of _ piece frame must be well =P S™#S atta this drawing will show how _ steamed before the stick TOE-CORDS to taper the frame correctly. ie Stat bent = form the ENTER FILLING eres gerne tage nag aaa _ usual curving bow. which must exactly The Cree makes his shoe EUTTHLALT alike, two pairs of holes are _ With an extremely high up- bored in the toe and heel, curved toe, sometimes HEEL oe the gee Eh car to- 2 Seg makes it neces, OFM ie fame chould vow be _ sary to construct the frame LANYARD thoroughly soaked in hot 4 ‘with a very long and nar- water by winding several _ row toe, otherwise the high- cA =? thicknesses of burlap Bly elevated toe would strike f around it and soaking the *. thé knee and interfere with ‘Sy a a and rags. Pour boiling water _ the usual stride when walk- € names of its component parts on the wrapped frame at _ ing. The high curve also requires an intervals of 14 or I5 minutes, then let extra crossbar across the frame to give the it stand for an hour. This will render i= "necessary curve to the filling. But the the frame fairly pliable, when it may be high curved toe is bad for hill climbing, and bent over the drying mold, shown in 129 130 Fig. 4. This frame may be roughly put together from any lumber found about a home. Complete dimensions are shown in the figure. Leave the frame on the form for two weeks, when it will have a per- manent set in the desired shape. The exact position for the two center cross-braces is best determined by experi- ment. Spring them in the frame about 15 in. apart, and balance the frame across the clasped hands between the braces. The shoe should almost balance at this point. Shift the braces so that the heel is about 1% oz. heavier. This insures the heel of the snow-shoe cutting down, and keeps the toe nearer the surface. The crossbars are I in. wide, and 5 in. thick. Make them of ash to the shape shown in Fig. 5. Each end of the brace is mortised or let in the sides of the frame. A sharp %-in. chisel will come in handy for cutting the mortise, which must be 14 in. deep. Take pains to make the ends of the braces a nice snug fit in the mortises, so that the spring of the frame will keep them solidly in position. The small upper cross-brace shown in Fig. 2, is only necessary when the toe is much up-curved. this brace may be omitted. After finishing the frame, smooth all surfaces with sandpaper, and _ slightly round off the top and bottom edges of the frame and the edges of the braces so that MUNI UM HW Wl FIG.4 Dimensions of the snow-shoe frame and the drying mold over which the sides are shaped FIGS the filling may not chafe across the sharp corners. To preserve the wood, a coat of common linseed oil may be wiped on the wood, but do not put anything else on the frame. Some cheap factory-made snow- shoes are varnished, but no Indian or woodsman would make or use a snow-shoe In the straight or only. slightly up-curved model we are making, Popular Science Monthly thus finished, because the frame would prove slippery and treacherous when cross- ing logs and ice, causing accidents. The crossbars are of ash fastened with tenons to the ends to fit in mortises of the frame The Indians and woodsmen still fill their frames with deer, moose or caribon hide, but the white man substitutes cowhide for the center and calfskin for filling the ends. Lacing in the Pattern Regular rawhide or cowhide belt-lacing is very satisfactory, and this may be pur- chased in long strips in suitable widths. For the center, use 3%-in. lacing, and for the toe, heel and lanyards use the 4%-in. width. This may appear a bit wide, but as the thongs are soaked and stretched before use, this will make them very much smaller. As the leather cannot be well joined with knots, the end of each thong is joined to another by slitting the end of each to form an eye, and the two thongs are joined as shown in Fig. 6. For weaving the strands a lacing needle or bodkin is used. This is simply a piece of birch or maple whittled shuttle-shape about 2 in. long, 34 in. wide and 4 in. thick. The bottom side is flat, and the top is convexed and rounded as shown. In the center is an oval hole for the threaded end of the thong. By turning — the shuttle slightly, the thong is nipped securely while it is woven and stretched in place. Cotton cord may also be used for filling the frame. It answers very well where a cheap snow-shoe is desired for occasional use. However, as the labor is the same, it is better to make a hide-filled shoe in the first place, as cord will not stand much ~ hard use. For cord, pick out a heavy twisted or cable-laid fishline for the center, — and use a smaller size line for the ends. As shown in Figs. 1 and 2, the center of : the shoe is filled with woven hide laced — over the sides of the frame. The ends—toe > and heel sections—are not laced around the frame but are woven through a strip of i a oa hide called a lanyard. This lanyard (Fig. 1) is laced through the frame in double holes bored through the sides in _ practically the same way a tennis racket is strung. About six pairs of holes should be drilled through each side of the frame _ for the heel-lanyard, and about seven pairs _ of holes through the upper part of the frame for lacing in the toe-lanyard. Drill the holes clean, and cut a shallow groove be- _ tween them so that the thong will be slightly countersunk between the holes. In Fig. 6 _ is shown how to space the holes and make the half-hitch in the lanyard. Start the lanyard in the left hole drilled through the % cross-brace; lace through the first pair of holes in frame, make the half-hitch shown, and continue up the left side of frame and down on the other side, finishing in the hole from which the start was made. As knots will slip in fastening the thongs, most makers weave back the end of the nyard through the holes in the cross- Rctice to keep the end from slipping. The lanyard for the heel-section is placed in 1 the “same way as that of the toe. . Filling the Toe and Heel _ Every maker of snow-shoes has his own Pp: articular way of weaving the hide to fill is frames. Many of the patterns used are uite complicated and would be impossible ‘to Samia explain by word or picture. wever, any amateur will, after a little experimenting, hit upon a good method of saving the strands. As a fairly open or soarse mesh is best for all-around use, the ag pattern pictured will be found y and satisfactory whether hide or cord 5 q As shown in Fig. 7, the first strand is at the lower left corner of the ard-loop on the cross-brace. It is tied up to the last loop of the lanyard, wisted around itself and carried down to Popular Science Monthly 131 the first lanyard-loop on the right side on the cross-brace. It is now twisted around itself and carried over to the lanyard on the side, twisted about itself and thence across the frame. As each Ary a FIGS. The method of spacing the holes for the half hitch in weaving the lanyard strand is marked in the drawing, it will be an easy matter to follow their course. The same method is used from beginning to end. By keeping the drawing beside you, the pattern can be followed exactly. The strands will be pulled somewhat out of shape while weaving them, but this is easily straightened out from time to time as the work proceeds, by means of a wooden fid. This is merely a round stick of wood about )% in. in diameter and whittled to a point at one end. The chief thing to keep in mind is to stretch the thongs as tight as possible, and this is done by using the leather strips while wet, and pulling each strand up as tight as possible. The heel- section of the shoe is filled exactly in the same manner as the toe. The center is a trifle more complicated to weave, but a careful study of Figs. 8, 9, 10, and 11, will show how to do this correctly. While the center may be filled by weaving the thongs in and out in a square pattern, the manner shown in the drawings is a a! \ FIGS | * different stages in building up the lacing within the frame. The center part is a little more _— to weave than the toe, but a square pattern can be formed readily if it is preferred 132 particularly strong and serviceable way, and is not at all difficult. Begin by putting in the toe-cord first, as shown in Fig. 8. The thongs should cross the frame about six times, so as to form a strong mainstay. As shown in Fig. 8 the common clove-hitch is used for binding the strands solidly together. The end is then twisted around the toe-cord and carried up and over the upper cross-brace, then twisted down and around itself to form the first toe-cord stay or support, which is clearly shown in Fig. 9. The work of filling the center may now proceed, as shown in Fig. 10. As each strand is numbered in the drawing, the work of filling the frame will be found easy, using the illustration for a pattern. The toe-hole—through which the toe of the moccasin works up and down in the act of walking—should be about 4 in. wide. Continue filling the center until about a 4-in. space is left, then stop twisting the strands around the cross-brace and weave through the toe-cord. It is important to finish the toe-cord as smoothly as possible, for any knots or roughness here will chafe the feet. All splices should be made as close to the frame as possible, but not on it. If the pattern is followed, the filling will end in the middle of the toe-cord. Weave it through here several times to finish and secure the end. The toe-hole may now be finished by taking a new thong, and looping it around the cross-brace beside the toe-hole. Carry the end down close to the toe-cord stay, loop it around the toe-cord, then carry back up and around the cross-brace and wind it down over the toe-cord stay, closely wrapping it as shown in Fig. 11. The end is now wound around the toe-cord over to the toe-cord stay on the other side of the toe-hole, which is wound in the same way as the one just made. Secure the end of the thong by weaving in and out between the toe-cord strands three or four times. The snow-shoe is now finished, and it should be laid aside to thoroughly dry. This must be done in an ordinary room, because the hide will not prove durable if exposed to bright sunlight or if the drying is hastened by putting the shoes near the fire. The regulation snow-shoe harness, con- sisting of a leather stirrup for the toe, and the instep and heel-strap, is more comfort- able than a thong and when it is adjusted to the foot the shoes may be taken off and put on quickly. Popular Science Monthly Climbing an Unspiked Pole by Means of a Piece of Heavy Wire O CLIMB a pole of any kind that is not fitted with spikes or cleats and where lineman’s spurs are not available, or a pole such as a flag pole, where spurs can- not be used lest the - polished surface be marred, take a piece of heavy wire and make a loop around the pole about 4 in. larger in size than the diameter of the pole and make a smaller loop in the other end to fit one foot. When you clasp the pole with the arms and raise the foot, the loop on the pole will slip up, and when the weight of the body is put on it the large loop will bind on the pole and hold the climber in compara- — tive safety until a Climbing pole with grasp is taken higher — looped end wire up on the pole. Making Tenons on Thin Rails and Slats N making tenons on the ends of some ~ slats for the sides of a mission Morris chair, I found difficulty in cutting them out with a saw in the usual manner, because ~ the slats were so thin. The following jig, set up in a few minutes, enabled me to cut perfect tenons 14 in. thick on material © 3g in. thick and 2 in. wide, removing 1/16 in. from each side. To a hardwood base- piece, A, about 12 in. long and 6 in. wide, — two pieces of the same material, B and C, — were nailed on its upper surface, a piece — being used between as a gage and the nails driven diagonally to fasten ‘them tight. Crosspieces of material about 1 in. thick and with square edges were then nailed — on at E, F and G, the latter two being spaced by the thickness of the tenon saw- — blade. An auger-hole 1 in. in diameter was bored as shown to cut halfway in each piece F and G. The whole was nailed to — the work-table near its edge and anordinary clamp held it in position, the clamp being _ fastened with two 3-in. nails driven part _ way in and bent over. A tenon-saw with an adjustable back SERBS eee ans Tar il alien Setar must be used and it is set as follows: nittle four small pieces of pine 1/16 in. nick and lay a pair of them on each of the _ pieces F and G near the opening between them. Slip the saw in the slit and let the _ back slide down to rest on the pieces. imp the back of the Popular Science Monthly 133 farther and remove the saw from the slot. Drive the stock back until the end is under the saw and make another cut. Give the clamp-screw one complete turn and saw another cut. This operation is repeated until the first cut is almost reached. Split off the bits of wood left between the cuts with a chisel and then with the stock set so that the end is under the slot and the saw in position, begin sawing and slowly screwing the piece forward with the clamp. The result will be a perfectly cut tenon. Each tenon can be cut similarly on both sides. Generally the tenons used need be only ¥% in. long, or even less, and they are cut very rapidly, evenly and not too smooth so that they can be driven home in the mortise. The dimensions of all the pieces used will depend upon the material to be cut and the length of the finished slat. The dimensions given are for making tenons 3 in. long on each end of slats Io in. long, 2 in. wide and 3¢ in. thick. The same device can be used for cutting tenons on thicker stock, but several cuts are necessary and the channel must be deeper. Swinging Stanchion That Gives Comfort to the Cow HE stanchion described herein has given perfect satisfaction upon a dairy farm in New aw at the handle and ove the small pieces. s Btlade will sink 1/16 ¥ i into the pieces B and C. Take the piece on ‘which the tenon is to be at, mark the distance for ieee BE neth of the tenon d draw a fine pencil ? with the aid of a 1 Insert the slat xetween the pieces B | C and under the _ pieces and drive it n gently with a mallet. the line drawn isses the saw-guide, as by means of the hen ee.” Hampshire, the propri- etor of which devised and built it himself. The old chain-posts were torn out and the new swing- ing stanchions installed while the cows were in the pasture during the forenoon. The stanchion can be instantly locked from the front or back, and will hold the most unruly cow safe and without discomfort. It will permit enough end movement so that the cow can lie down or get up easily, and allows sufficient freedom of i, round hole, puta piece “of steel the thickness of the saw-blade i | slot—a square blade may | be used for this purpose. By means of the . mp, screw the stock forward until the line is just at the edge of the steel; Saw until the gagewill prevent it cutting any The s swinging of the stanchion gives the cow plenty of room for move- ment with comparative comfort movement in any direc- tion for the greatest comfort. When the cow is lying down the stanchion will accommo- date itself to the direction of the neck and there will be no evidence of difficulty in breathing or of the discomfort caused by a 134 cramped position of the neck,. which is often endured in silence by cows in the rigid stanchion. The pieces necessary for the stanchion can be purchased from a mill Pe, Oe ere Ce EY Lf ine, s cs fs o = 5 5 3 . tes BOTTOM OF PLATE 4 yt On , 3 ' 4 ’ + |i ; ' H . -— : : ae : toh, ‘ 1or"t yo)! ‘ 01° : Plot . ! . H ca w 0 ; : | STOP BX5x6 ' ' 4 | |EACH SIDE oF ‘ 4 1 [2X4 UPRIGHT ‘ ’ ‘ ' ' , o ’ ‘ ' : ' 1s : eapeeeem ' ” 4 eee L--44@t=---bt e: i ' ' , ; pe} ; & ‘ ae ' ‘ 1 A J 4 ’ a ; ‘ ’ ; i ‘ t. ry ' ' Lt e ’ t ‘ ' M gs I : ' ‘ t ' } . f. 5 . 1 : ‘ H ' ‘ + rf ’ H ' . ’ ‘ s : ’ H i : ’ ‘ ' : ' e , ’ ' ¢ ' ’ ' ry 1 . ! : : Ey ' ’ ‘ ' 5 wv , : ¥ 1 Zk: Z : ni woop washeR 1X2 BE CE st ot’ Ces kasce IQboceesp ty Details of the stanchion showing parts that swing on a lag-screw at the top and bottom or cut from trees on the farm wood lot. The material list for each stanchion is as follows: 1 base A, 121% in. long and 2) in. square 1 header B, 221% in. long, 214 in. wide and % in. thick t header C 71% in. long, 214 in. wide and 13 in. thick I standing side D, 60 in. long, 214 in. wide and 13 in. thick I swinging side E, 60 in. long, 21 in. wide and 14 in. thick 1 hinge block F, 3% in. long, 4 in. wide and 1% in. thick 1 lock G, 534 in. long, 134 in. tapered to 1 in. by 14 in. thic 1 washer 24% in. sq. by % in. thick with 34 in. hole 7 carriage bolts 5/16 by 3% in. 1 lag-screw and washer 5 by g in. 1 lag-screw and washer 5% by 7 in. 1 strap hinge 3 in. and screws %% in. 4 screws for the hinge block 114 in. No. 10 The side pieces may be made of hickory or oak poles 2 in. or more in diameter with their ends trimmed to enter the slots in the header and base.—CHARLES A. KING. Popular Science Monthly A Writing Ink Made from Discarded Typewriter Ribbons F the worn-out copy-ribbon from the typewriter is put in I qt. of distilled or rainwater and allowed to stand, it will make a good writing ink. When the fluid is used up; add more water. The record ribbons will not do; a copy-ribbon such as is used to make a letter press copy is the kind to use. Rope and Pulleys for Hoisting a Bicycle Out of the Way HE accompanying illustration shows a novel and handy arrangement for putting a bicycle up out of the way. The device will be especially appreciated where floor room is scarce and where a bicycle is to be put away for the winter. Procure a sufficient amount of small hard twisted cotton cord, 2 small screw-hooks and 3 small pulleys through which the cord will run easily. Fasten one of the pulleys a trifle to one side of the center of the roof and run the rope through it. Cut a small strip of wood 3 in. wide and slightly longer than the distance from the seat on the bicycle to the handlebars. Into the top side of this strip, one at each end, screw the two remaining pulleys with the line of © direction of the wheels running parallel — with the length of the board. Into the un- — der side screw the two hooks, far enough apart so that one of them will hook into the — saddle and the other on to the handle- frame. Run one end of the cord through Ropes and pulleys attached to rafters for suspending bicycles up out of the way these two pulleys and attach to a similar — point in the roof directly opposite the first — pulley. To raise the bicycle, simply pull — the unattached end of the rope and fasten — it securely.— DALE R. VAN Horn. q ) : d : ] ‘ ’ 5 = = ANY persons would like to make = motion-pictures of their friends, but ; the machines on the market are too high-priced for the average purse. ‘The large companies take, print and pro- 3H their pictures with separate machines. - Foll all three mechan- i Bik isms, the chief cost H | ' Theheartofthe |, “machine to be de- scribed is the -cylinder-shutter and intermittent shifting device 1% Ss shown at B, as in detail in the upper left-hand corner of the drawing. It consists of a round wooden cylinder of the dimensions given. Through one of the diame- ters of this cylin- der is mortised a rectangular hole Tin. by 2 in. The ets or pro- jecting pins C are set at a distance 90 deg. point, using the center of the mortised hole as a base. These pins should fit the per- forations in the standard motion-picture accurately, and the points should be rounded so that they may enter the perforations without difficulty. : The camera consists of very few parts and is of %% in. from the used for taking, printing and projecting the pictures by the bracket D1, In the drawing of the inside of the camera, may be seen the shutter in position to admit light to the film. The cylinder revolves backward, and the pins engage the perforations in the film, pulling it downward exactly 34 in., while the light passing through the lens is cut off from the film. After the film comes to rest, the cylinder continuing in its revolution, the light is again ad- mitted to the film through the opening in the cylinder, thus making the exposure. After this the film is again shifted ready for the next ex- posure, and so on as fast as the cylinder revolves. The usual speed is sixteen pictures per second, which means eight revo- lutions of the cylinder per second. The film is taken from the upper roll, sup- ported in the top of the camera box and after passing behind the spring-actuated roller-guides Et E2, it passes downward to the take-up roll, which is connected on the outside of the camera, by means of a belt, to a 4-in. diameter driving-wheel. This belt is left _ loose, so that it will pull the film only when 135 136 it is shifted by the cylinder-pins. The box or case for the mechanism should be about 12 in. in height and 31% in. wide, the length from front to back being determined by the focal length of the lens. If it is desired to take an extra-long film at one time the box can be made higher to contain larger rolls. The cylinder is supported by axles J, J, which pass through holes bored in the sides of the camera-box at the proper points to bring the cylinder to within 1/16 in. of the film. To one of the axles is attached a pulley 1 in. in diameter, belted to the drive-wheel with a belt stretched fairly tight. The drive-wheel is made in two sections of different diameters, which are fastened together to form one wheel, the outside section of 8 ins. diameter being belted to the cylinder, and the other section of 4 ins. diameter being belted to the I-in. pulley connected with the take-up roll at the bottom. The camera-box has an aperture I in. high and 11 ins. long cut in the back, to afford passage for the pins when pulling the film, and to allow using the machine for projecting the pictures. When used as a camera, the opening is made light- tight by the pivoted cover H. This is opened to allow the light to be projected on the film when used for projecting the finished pictures. The camera-lens may be of any con- venient focal length. It is mounted in a hole cut in the front of the box, opposite the hole in the cylinder. The lens should be mounted for shifting it backward and forward to obtain the proper focus of the image, as observed on the film through the aperture at the back of the camera. The camera-box must be made light-tight. Now load the camera with the sen- sitized film. This must be done in a dark room, with only ruby light. This film can be obtained already perforated from any dealer in photographic supplies. The film is passed behind the pressure- guides and the cylinder-shutter, as shown in the illustration, with the dull or film side toward the lens. It is fastened to the lower take-up shaft by means of a thumbtack, after which the camera is closed. When taking the pictures, the camera should be supported on a table or some other rigid surface. Popular Science Monthly The driving-handle, attached to the driving-wheel, is turned at a speed of two turns per second, making sixteen pictures per second, or eight pictures per turn. After the film is exposed it is ready for development, which is accomplished in the same manner as the development of ordinary films, except that an arrange- — ment for handling such a long film is necessary. Make a square wooden frame to fit inside the developing-trays used, which should be at least 14 ins. by 17 ins. in size. The film is wound around the frame with the emulsion or dull side outward and is then easily handled in the developing solutions. The film is left on this frame for all manipulations until dry, when the negative is ready for the printing of the positive film. In the dark room, wind up the negative and an equal length of positive film into a roll, with the emulsion sides in contact. The two films are then passed through the camera together in the same way the original film was passed through in taking the pictures. For printing, the lens is removed from the front of the camera and the camera pointed toward a bright light. The camera handle is turned at the proper speed to give a correct exposure to the positive film. The correct exposure is best determined by making short ex- posures on a few inches of film, until the right effect is obtained. Then the full length is printed in the same way. The positive film is developed in the same way as the negative. After wash- ing and drying, it is ready for projection. The finished positive film is placed in the camera, with the pictures upside down and the dull side toward the back aperture, which is opened. Through it, the light from a stereopticon, or some other form of brilliant illumination, is projected on to the film. The picture is then focused on a screen placed in front of the camera-lens. The pictures are projected by turning the driving handle at the same speed that was used when taking first them. | If a very brilliant light is used for projecting the pictures it is necessary to cover the film when it is not running through the camera, as the film is in- flammable and will quickly catch fire from the heat. sae ele Popular Science Monthly An Adjustable High and Low Stool for the Typesetter Bee printer who preferred to be “\ seated while setting up type and yet did not relish the inconvenience of jumping off and on a high stool to reach Two heights for the seat are obtained by merely giving the top a slight turn the lower drawers, solved the problem with the adjustable stool illustrated. To make it, four stool tops are fast- ened together with four floor-pipe flanges, one cross, and four pieces of pipe, all 34 in. in diameter. Both pairs of pipes are cut and threaded to the same length, two for the high stool and two for the low, the two former being of such length as to make the stool about 24 ins. high and the other pair making one I4 ins. The flanges are screwed to the under- side of the stool tops in the center and the pipe screwed into them. The cross is interposed in the center. When chang- ing from one position to the other it is only necessary to give the stool one- quarter turn and a different height is obtained. An Easy Way to Remove Old Varnish or Paint properly refinish a piece of old furniture the surface of the wood must be cleaned so that it will present a new and clean appearance. The old varnish must be removed and the wood sanded down and made like a new piece of timber. The most difficult part of the work is to remove the old varnish. 137 Many patented varnish removers are on the market, but where there is just a little work to be done it does not pay to purchase a full can of the liquid. Varnish may be removed by coating the surface with a very hot solution of strong glue, applied thin, and allowing the job to stand over night. The next day the varnish will be found hanging in flakes, and just a little rubbing with fine sandpaper will make the surface clean, leaving nothing but the wood showing. It is then ready to be prepared for the new coat of varnish. Sliding Exhibit Tray for a Show-Case Top Be JEWELER having a number of long show-cases of the all-glass variety, wished to keep the tops as free from scratches as possible and yet give plenty of free space for showing the goods within the case. He accomplished his purpose by using the sliding tray shown in the illustration. The tray was mounted on a board extending from the front edge of the case to the back. The entire affair was made of light material about % in. thick, and was constructed of solid mahogany to match the wall fixtures. At the ends of the board and on the underside were fastened two cleats to extend slightly down over the glass top edge. Just back of these pieces and on the underside were glued strips of felt so that the weight of the entire tray and board rested only on the edges of the show-case top. Within the tray was pasted a square of green baize cloth to give it added neatness. The tray may be made round, square or rectangular, as desired. When The sliding tray provides a place to show jewelry without laying it on the glass in position on the case top it can be slid along to any place where it is to be used in showing the goods, or it can be lifted entirely from the case and set aside. 138 Popular Science Monthly Sawing Boards on the Table of a Milling Machine HE best machine for cutting boards in a machine shop is the milling The guides A are made to machine. A. Application of a gage on a milling machine table to guide boards in cutting them hold the straight edge B. These are fastened to the milling-machine table so that the straight edge will guide the board as it is being sawed. By means of the slots in the guides the straight edge can be set so that any width of a strip may be cut from the board. A wood- working saw is placed on the milling. « machine arbor and the table located so that the saw runs in a T-slot of the bed. If there is no woodworking saw at hand a large slitting saw can be used and the table swung at an angle of % deg., if the miller is a universal. This angle will cause the saw to cut a little wider than its thickness and prevent the saw from sticking CLARENCE ANDERSON. Making a Small Gas Blowpipe of Brass Tubing HE main tube of the pipe is made of a piece of %-in. brass tubing about 9 in. long with a gas cock soldered to one end for controlling the supply of a a Ps ne ; _< > aria, A GAS TAP GAS PIPE — Brass tubing with auxiliary air tube attached for a blowpipe gas. The air pipe consists of a 4-in. brass tube, also 9 in. long, cut and formed into a tee, the stem being 3 in. long. One end of the cross-piece is bent at right angles and the other flattened to fit the main pipe where it is soldered. A piece of rubber tubing is used to make connections between the gas cock and~ Another piece of small the gas jet. tubing is fixed to the air pipe. A False Ceiling of Lattice Work for Ornamental Purposes (jy photographer making post-card — pictures leased a room that had a high ceiling, and as he desired to have a small room in the front part of the store, it was necessary to reduce the height in order to get a good effect. So he decided to construct an intermediate | ceiling, and not caring to make it solid, he used lattice work instead of wall boards or panels. Boards % in. thick were procured and cut into */,,-in. strips at a mill. These were woven together the same as any lattice work, making the spaces as wide as the strips. After placing the lattice and a border slant in position it was stained in colors to give a figure effect. The illustration shows how the figures were made, with the shaded portion in a alls iE =n STRIPS CUT FROM BOARD The lattice as it appeared after being stained and placed in position for a ceiling dark color and the light part of a shade to harmonize. There is also shown the method of hanging the electric fixtures to make them appear attached to the lattice work. The strips being thin are very easily woven into place. The long pieces are spaced on a floor, or rack, made of boards and set on saw horses. They are then fastened temporarily at one end with nails, or, better still, loosely with screws. The ‘‘weave’”’ is then inserted by pulling: up each alternate “‘warp,’’ and fastening it temporarily with small nails driven through the strips at the place of cross- ing, but not far enough to enter the work table. This will hold them in place until a whole ceiling or border width is made, when it can be fastened in the allotted place on the wall. . i p b 4 i SPEEDY coasting bob which is large enough to accommodate several passengers has ever been a favorite with boys wherever snow falls. The sled illustrated is an especially good design in that it is a fast, smooth runner, strong and serviceable but not too heavy to be pulled up grade. A careful study of the drawings will make it clear just how the runner is made. The seat should be made from some light but strong wood, spruce being the first choice. Cedar, pine and hemlock are also good, the preference being in the order named. As shown in the profile sketch and in the scale drawing, the seat is 14 ft. long and 12 in. wide. The rear sled is 4 ft. long and 18 in. wide. The sides are made of oak 114 in. thick, and should be 4 ft. long and 5 in. wide. The two cross-pieces are of 114 in. oak, mortised into the sides and firmly fastened with 3-in. flat-headed screws. The rearrocker-blocksareshaped as shown at A and B in the drawing on the following page. These should be of 114 or 1% in. oak of the dimensions given. Two pairs will be needed, each pair being mounted to a flat base of oak 1% or 2 in. thick, 12 in. long and the width of the sled. These curved It should be of 4! rocker-blocks selected stock, | 2 are solidly 1% in. thick, = * bolted to the without large : | | ES base and the lat- knots or other = - re DES ter is mortised defects. The { ( ae 2 into the top sides cross-pieces + | of the runners which form the : Lie and screwed to foot-rests are ; | them, as shown sawed from —_I] WE 7S i] Sa ae it Hy Fk 34-in. oak, and = fi Py iio i ii 6} i Through the should be 22 in. 0 a eS ka 2 a | i curved cheeks of long and 3 in. wt the rockersa hole wide. These cross sticks are solidly screwed to the under side of the seat plank, 16 in. apart, as shown. On the upper side of these rests, a strip of oak I in. square is solidly screwed to the foot-rests flush with the ends. This serves to strengthen them and also adds to the appearance. At 18 in. from the end selected for the forward end of the sled, bore a hole in the center to admit the steering post, as shown. The profile of bob and plan of seat board with crossbars for foot-rests and tie-strips at the irends is bored and a 54-in. iron bolt is run through. This ‘‘teeter bolt’’ construction is the very best method of fastening the rear sled, and is much superior to the usual rigid crossbar type commonly used. The illustration D is a kind of X-Ray sketch showing how the two pairs of rockers are assembled—the top pair being bolted to the under side of the seat. The runners are shod with 114-in. half- round iron, which is solidly attached to 139 140 runners with deeply imbedded screws. The front sled is made exactly to the same dimensions as the rear sled. The top and the lower blocks should be 8 in. long, cut from 1% or 2 in. oak, and Popular Science Monthly the post, as shown. This makes a very © strong steering gear, which will not work loose with hard use. That the coasting sled may prove attractive it should be given two or - — omc es bead en 0, ——* mae Bd ae a wren «3 Na RA se, i} i 1 = i C “ Ake ! the necessary parts of the runner and cross-section of the rocker for the front bob should be the width of the sled and seat respectively. The two middle blocks on the top may run the full width, but will serve just as well if made 8 in. square and the same thickness as the others. The lower half of the first middle block is tapered to a rocker shape, and to make the sled turn easily a large, flat iron-washer is placed between the two. The two upper blocks are solidly: screwed together and to the under side of the seat—the centers exactly 18 in. from the forward end. The two lower blocks are likewise screwed together, and the lower one is mortised into the top sides of the sled and screwed firmly to it. The steering gear consists of a % or I-in. iron post, to which is bolted an iron wheel or crossbar known as a tee. If an old brake wheel can be picked up, such as is used on railroad cars, this will make a splendid steering wheel, or lacking this, a crossbar of iron will answer just as well. That the lower end of the steering post may be solidly affixed to the sled, the end of the post is threaded, and a large lock-washer or plate about 4 in. square and ¥% in. thick is first screwed on. This plate is provided with four screw-holes in which heavy screws are turned to fasten it solidly to the underside of the lower block which is mortised to the sled runners. A second nut is screwed on the end of three coats of bright red paint, and finished with a coat of outside spar varnish. The steering post and wheel or tee may be finished with aluminum paint or black enamel. If a cushion is desired, this may be cheaply made of tan khaki, padded with cotton, or an old comfortable may be cut to the desired width to slip in the cover. The best way to keep the cushion in place is to fasten it to the seat with several straps and buckles. A Shoe-Scraper Made of a Wagon Step DISCARDED wagon step screwed to the side of the porch steps makes a good shoe-scraper. It is set off from the steps and the scrapings from the shoes fall on the ground and not on the steps. It cannot clog, and being fast- ened to the side of the steps, it is not in the way. It does not mar the step nor is it liable to cause injury. Its cutting edge can be filed as sharp as desired, and it will hold its shape and position. Scraper attached to the side of a step Simple Means of Removing Tarnish from Silverware SIMPLE method for removing tar- nish and discoloration from silver- ware is as follows: Fill an aluminum or porcelain dish with warm water and dissolve in it some sal soda. The tar- nished articles should be immersed in this solution for several minutes, when the silverware may be removed, bright and clean. The Tea-Table Idea Applied to the Kitchen BALTIMORE woman, Mrs. Jo- seph Eiseman, has patented a new kitchen device which is designed to save A light table on wheels is a great con- venience to the housewife in the kitchen women many steps in the process of dish washing and other household labors. She had her husband build for her a light kitchen table on wheels, with a handle like that of a baby carriage, so ___ that it could be pushed around the kitch- en, just like a drawing-room tea-table. a its four sides the table has a series __ of hinged leaves, which ordinarily hang _ flat. When desired, they can be braced _ upright, which practically doubles the ___ table's size, or again they can be folded _ entirely upward to convert the top of __ the table into the bottom of a box having ho top. ~ To the housewife the advantages of __ this arrangement will be immediately ob- _ vious. The table may be wheeled just _ Outside the dining-room door, where the _ dishes from the dining-room can be _ Placed on it at once. When the meal is _ ended, the table is wheeled back into the : 3 kitchen. There it can be wheeled directly | _ tothe sink for the washing. Popular Science Monthly 141 Quickening the Flow of Oil When Cold URING cold weather it is difficult D to make heavy oil, such as that used for motorcycles, run out of a small opening. If a piece of }4-in. copper tubing is bent in a U-shape so that it will go inside the opening and admit air, the oil will run out much faster. If this tube is made long enough to enable one end to be placed in the mouth so that air may be blown into the interior of the can, the heaviest kind of oil can be forced out at the rateof more thana gallon a minute—-NORMAN S. McEWENn. Using Discarded Range Boilers for Air Pressure Tanks HOUSANDS of range boilers are thrown away every year, as soon as they become corroded, even in one or two spots. They may be used for air- tanks in brazing, by carefully cleaning the spots where the leaks have been and then soldering pieces of sheet brass over the holes. How to Make Spiral Springs with Breast Drill PIRAL springs can be easily made by means of a small hand drill and a vise. The drill is fastened at the knob A in the vise B, as shown in the illustra- (2 Winding spiral springs is an easy task with a small hand drill held in a vise tion. A core C is placed in the chuck along with the end of the wire. The wheel can be turned with one hand and the wire D guided with the other. The core C may be any size desired, accord- ing to the spring —JOHN BANSERT. 142 How to Build Bucket Seats for Automobiles THOROUGHLY satisfactory pair of bucket seats may be built from the following specifications. Seats of this type The popular bucket seat as it is ap- plied to the chassis of an automobile are very popular among sportsmen who are rebuilding used cars into speedy roadsters, as well as with the prominent race drivers, because of their light weight and simplicity. and economy of construction. Two pieces of sheet metal are required for each seat. The back and sides may be cut from a piece 414 ft. long by 2 ft. 4 in. wide, and the bottom from a piece I ft.gin. square. A rather heavy metal that will withstand hard usage should be selected. The greatest difficulty in this kind of work is in obtaining a pattern. u Popular Science Monthly generally folded over or rolled about a wire, to give a smoother and stiffer edge. Avstrip I in. wide along the lower edge of | the pattern for the bottom is folded up to form a means of holding the cushion in the seat. The metal should be first cut to the outside dimensions, and then the pieces — between the lugs cut away. The lugs then — may be turned up and the bottom secured in the seat by means of rivets through the lugs and the sides or back. One rivet of fairly large size in each lug is sufficient. Large-headed rivets spaced evenly will — have a decorative value. As the metal for this work is usually © rather light, braces may be applied to good advantage: A form which is simple and — effective may be made from a piece of © strap-iron bent at right angles, one end — being riveted to the side and the other end @ : to the bottom. The picture shows a seat of this kind in” a converted roadster which has been suc- — cessful on the track. This is a typical ex- — ample of the location and appearance of the ~ bucket seats.—S. E. Grpss. A Cork Substitute for the Toilet Flush-Box Ball | NE of the most troublesome devices to repair about the home is the rubber tank bulb in the flush box of — the toilet. The rubber bulb itself — does not wear out, but the brass bushing into which the stem is — screwed becomes loosened so — that the bulb does not fall squarely into its seat. This condition will The dimensions are given so that they may be laid off with the aid of a rule and a pair of dividers or a compass. These dimensions should be followed closely so that there will be no difficulty in assembling the seat. The pattern for \o i7'"—\ fu : result in leakage. It occurred to me— that a cork ball | should serve this— purpose as well as a rubber bulb. Ac-— cordingly a cork ball was purchased from — a dealer in rubber goods and a small + hole was drilled * through it. A brass— + rod of the same di- ee the back and sidesis 77 shown in the draw- ing. As the bottom lines are very diffi- cult to compute accurately, it is much easier to cut the metal as shown, and then remove the surplus after the bottom is riveted in place. . The upper edges are Pattern for cutting the sheet metal to. shape the seat-back and bottom ameter as_ the old - brass stem was then secured and threaded at one end for a length to equal a little more than the diameter of - the ball, which was placed between two nuts, A and B, with an extra nut at B a eT oe See a lock-nut. The ball was composed of ground cork held together with a water- proof adhesive and molded into shape. These balls cost considerably less than a -tubber bulb. The arrangement worked ——= = and ie \% Onde “SY perfectly and the lasting qualities of the cork were superior to those of the rubber. A little leakage appeared at first, but after several days the ball had shaped itself to i he seat and the joint was water-tight. A small portion of vaseline rubbed on the | seat and the ball aids in making the joint close fitting. An accurate record of the Hi lasting qualities may be kept by placing is he date of its insertion on the ball with vaterproof ink.—L. S. UpHorFF. - Solution for Cleaning Steel Wire 4 HE wire parts should be run in a “4 tumbling barrel with about 2 oz. of castile soap and enough ground pumice to make a thin mud. After the parts are cut down until all rust and scale are removed, they should be washed in hot ‘soap solution and polished by tumbling tone fairly bright polish can be obtained by tumbling in dry sawdust with a little flour of pumice. An Indexing Hint for Readers of a Current Magazines 3 will often see an article of special imterest which he would like to read again or one which he would like to call to the attention of some other person. Much time would be saved if a short note were made mm the back cover or on the third page of the magazine, or in any other particular pot selected for the purpose. Simply the age number and the name of the person imterested with perhaps a word to denote va wa q a Popular Science Monthly with soap solution and steel balls; or a- N looking through a magazine a reader : 143 the nature of the article are all that would be necessary; as, for instance: Ernest, see Page 59—Diagram; Frank, Page 64— Mill, etc—JoHN HOEcK. Why the Tread on Repaired Tires Fails to Stick ROUBLE is often experienced in getting the tread to stick on small repairs. This may be due to any one of several reasons, the most common of which is that the cement has been applied over wet fabric. The moisture in the fabric, even if very slight will blow the tread loose. Another common cause for loose treads is the failure to roughen up the old carcass sufficiently. In this case the cement will not hold properly and after a few miles of running the repair will separate. It is also well to make sure that proper pressure-is being applied to the repair when it is curing. Photographic Focusing Table for Hand-Cameras OR those using hand-cameras with which it is necessary to depend on the scale attached for determining the proper focusing point,.the table given is of great value. It is not, however, of value to those who use “‘box”’ or other types of cameras having a fixed focus or standard focus. The table is especially designed to deter- mine the proper point on the focusing scale Distance of farthest point (of object) 2 | 3 | 4 5| 6] 8] 10] 15] 20] 30] @ wl 2i| 2] 22/2413 [3 [32] 3] 34] 83) 32] 4 al SIN JS 33] 3214 | 42] 43] 5 | 53] 53] 6 xz} 4 \\4 421 43/5%| 52] 6t] 63] 7] 8 § 5 rs 5 1532/6 | 62] 73] 8 | 83] 10 Shell TX \ Je |z | za] 88] 98] 20 [22 SI 8 eo NF 9 | 104] 113] 123] 16 g 10 ~ 5% IO | 12 | 133] 15 | 20 § 15 EN 15 | 17 | 20 | 30 A 20 Be 20 | 24 | 40 30 Se 30 | 60 2) ad Table by means of which the average focusing point on the scale may be quickly determined of the camera at which the pointer must be set when it is desired to photograph two objects, one nearer than the other, and to have both in sharp focus. 144 Suppose, for example, a near object is situated 8 ft. from the camera and a far object is 15 ft. away. In order to have both in sharp focus, you must find the figure 8 in the column at the left in the table; then follow across until the column headed 15 is found and the number 10% will be at their junction, at which the pointer should be set on the focus-scale. This will bring both objects, and all intermediate points, in sharp focus on the plate. If the near object is 5 ft. from the camera and the distant one is 20 ft. the focusing scale should be set at 8 ft. If the near object is 4 ft. from the camera and the far one is more than 30 ft. away, set the focusing pointer at 8 ft. If the near object or point is more than 30 ft. from the camera and the far object is also more than 30 ft., set the focusing pointer at infinity—1oo ft. The last figure in the first column is infinity point and the last column of figures in the table gives the focusing points when the far distant point or object is more than 30 ft. from the camera. Following is the explanation of the for- mula to find the focusing point mathemat- ically. Two times the far distance multi-. plied by the near distance will give the number which should be divided by a number found by adding the far distance to the near distance. The result is the focusing point.—GEo. H. Stipp. Fastening Brad-Awl Blades Securely in Handles EN used for boring very hard wood the blade of a brad-awl is apt to stick in the work so that the handle is pulled from it. This can be overcome to some extent by wetting the tang before driving it in the handle. This will cause a rust which gives a better grip on the wood fibers. Another and very satisfactory way is to secure the blade as shown in the illustration. Soften the extreme end of the tang by heating it red hot in a flame and allowing. The softened end of the tang is bent over into the wood to hold it it to cool slowly; then bend the tip slightly to one side. enters the handle and make a small hole Ascertain how far the tang: Popular Science Monthly through the side at right angles to the central hole. When the tang is inserted the softened end should just pass the side hole, which is 4 in. down from the end. A small nail or brad driven in the hole will bend the tang into a hook where it will be imbedded in the wood. The projecting end = the brad can be filed flush with the - wood. Preventing Melting Frost from Dripping on Window-Sills 5 HEN windows covered with frost are heated, the water drips to the sills and sometimes ruins the finish. The same is true when a room becomes filled with Va Metal trough on bottom cross-piece of sash to catch drippings from melting frost steam. To avoid this condition, fasten a small trough just below the pane, with on end slightly lower than the other. A small can or other receptacle may be attached to the nail used at the lower end, to receive the water.—EDGAR MORGAN. To Sharpen a Reed for a Clarinet. or Saxaphone HE reeds used for clarinets and saxa= phones must always be trimmed to take off the rough edge or to make them stiffer. It is almost impossible to do this — Popular Science Monthly perfectly with a knife or shears; but two new coins, preferably five-cent pieces, may be used with good results for the purpose. _ Place one on the top and the other on the _ bottom of the reed where it is to be trimmed. The coins should be perfectly even, above and below. Hold them tight with thumb and finger, with the reed between. Now light a match and burn off the end that pro- jects. Run the finger over the burnt end and take off all the ash. This leaves a perfectly smooth round edge.—W. C. Loy. Gluing Leather, Cloth, and the Like to Metal Surfaces EN undertaking to glue leather, cloth, labels, etc., on metal, it may be difficult to get the articles to stick. Where it is possible to completely wrap the metal, the following is a good plan: Cut a piece of print or newspaper, wide enough to go a little more than twice around the metal. Paste this up, allow it to soak a moment, then wrap it tightly around the metal, pasted side in. In drying, the paper contracts and pulls itself so tight as to form almost a part of the metal itself, which is then ready for use. If this plan is not practicable, try this: To 3 parts liquid glue add 1 part glycerin. Glue up the leather, cloth or labels with this preparation and apply directly to the metal. The glycerin prevents the glue from becoming perfectly dry by absorption or = evaporation, holding the labels, etc., to the j 7 metal by capillary attraction. Thawing Frozen Water-Pipes with an Electric Current 4 ERE alternating current is avail- , able, frozen pipes may be thawed by _ the use of a special transformer that has a § waste of magnetic energy, or with a _ choke-coil in series with each coil of an _ ordinary transformer. The secondary volt- age is usually low, but the current is high. : large magnetic leakage, or the choke- coils, permits the secondary of such a _ transformer to be short-circuited for several moments without injury. The piece of = frozen pipe is made a part of the secondary Circuit, the primary terminals of the trans- _ former are connected with the lighting circuit, and the voltage is adjusted until _ the desired current through the pipe is _ obtained. There should be the least possi- _ ble resistance in the secondary circuit; in _ other words, the secondary leads should be _ of ample size and as short as possible. Con- 145 nections can be made with a hydrant and a. faucet in a neighboring house, or with two faucets in two adjacent houses. Where only direct current is available, a motor-generator, or a dynamotor is neces- sary to reduce the voltage. A motor- generator is preferable, since the voltage is under better control. The volts, amperes and time required to produce running water in a frozen pipe vary largely and ac- cording to no fixed rule. Ordinary house pipes seldom require more than 30 to 50 volts and 500 amperes. Making a Bin for Storing Scrap-Brass Collected from Sweepings BOUT railroad shopyards, machine and car-shops there is always more or less scrap-brass and other valuable metals ~ lying around where it is likely tobestolen. The loss of thismetal in some shops amounts to a large sum of money each A bin or box to prevent thieves from taking out expensive scrap-metal from the shop-yards year. In order to provide a safe receptacle for this material the strong-box shown in the illustration may be provided. There is a hole of suitable dimensions in the end of the box, and a shelf is placed inside of the box about 12 in. in front and on both sides of it. This shelf makes the removal of 146 the material a difficult proposition. The shop cleaners deposit the metal in the box as it is gathered. To provide for easy removal a door is placed on top of the box and also one in front, both being locked with a key.—J. R. MINTER. Coloring Electric Globes for Decorative Lighting O color electric-light globes, make a coating as follows: Remove the gelatin from a quantity of discarded photographic films and dissolve them in equal parts of ether and alcohol; then color with aniline. This makes a coating that is impervious to water. Another method is to soak a small portion of gelatin in cold water until it has taken up all the water it can hold, pour off the surplus and add some boiling water—just enough to melt it—then strain it through several folds of cheesecloth. While still Popular Science Monthly White or light tinted paint required (1 gal. covers about 350 sq. ft., 2 coats); divide 3,044 sq. ft. by 350=83 gal. Darker colors (1 gal. covers about 400 sq. ft., 2 coats); divide 3,044 sq. ft. by 400=73 gal. An average painter will brush on well about 150 sq. ft. of paint per hour, 1 coat. Divide 3,044 sq. ft. by 150=20.29 hours; call it 20} hours for 1 coat, one man, and 403 hours for 2 coats. Add 3 hours for mixing colors, setting and moving ladders, etc. Total 43} hours. 12" Ay ES ' ; A) oe | fy hot add a little aniline color, previ- le 651 : ously mixed in a very little cold a) om water. Dip the globe in the warm = "kaa SEC 2 — solution and allow it to cool ina ~ =~ ~%——! oni vertical position to insure even coloring. This coating is not as good as the celluloid process first men- tioned.—A. ASHMUND KELLY. Estimating the Cost of Painting a Detached ‘House \ \ THEN a house is to be painted the following plan will be found useful in determining the area to be painted and the cost of materials and labor: Sides and ends 26+26+26+26 = 104 ft. around the house. Height at corners, 16 ft., multiplied eh” RBS Ba UD eee ne ore ae ch 1,664 sq. ft. 2 gables, 26 ft. wide multiplied by half Beemement: (6 1t.)<. h. oe . $52" Dormer 23 Xo9 ft.=22 sq. ft. 2 bay window ends 3 X 8 ft.= 48 sq. ft.... Side porch, rail and spindles (figure solid) 23 X 4 ft.=10 sq. ft.; 2 sides. . 20 2 newel posts, 16 in. around; call it 70 “cc Re a din. ccc aes’ BG Front porch floor, 8 X 23 ft. =184 sq. ft. Ceiling (figure solid) 8X23 ft.= RRR ete sia. ces ee Front porch rails and spindles. (figure OE | poo CS SRO ae ae te yo he Front steps, risers and treads, 5 ft. IAS TE MO i ge eee so ‘ 25 4 porch columns, 4 ft. around 8 ft. high 128 Cornice facing and eaves overhang on all sides 33 ft. 115 ft. around=... 402 Measurements for a house from which to obtain a base for figuring cost of labor and materials for painting MATERIAL Cost: 100 lbs. white lead bulk... ac... 23 gel et $5 scan Pure linseed off; . --) 5° '‘*" a ee ae Turpentine....... 7 MM eS) Ee eed Japan drier....... # pt. OM Sea: a eee ROGER. §. ieee ses I Ib. aces spon 90 Amount of paint, 8} gal. Labor cost, 432 hours at.....cents per Overhead expense, add....... % (15%?) of material and labor:cost .....54545.iss5. tbe Profit, add...... % (20%?) of material and Jabor cost... .:....s.shoe.ss casene ae oe ee Price to Charge Customer....... $e Figure 3,044 sq. ft. at your regular price per sq. yd. or per square and see how your estimating method compares with the above. A Knitting Needle Used for Testing Milk HE purity of milk is tested in Germany in a simple way. A polished knitting needle is held upright, dipped in the milk, and immediately withdrawn. If the milk is pure, some will adhere to the needle; but if water has been added, even in small proportions, the needle will come out perfectly clean. a A Perfected Slider for Tuning Coils in Aerial Apparatus CONTACT for tuning coils that actual- ly slides and does not scrape is illus- trated. Ordinary sliders make such un- reliable contact and wear out the wire so quickly that they have generally been discarded for the more cumbersome switches. This slider is useful for both The metal gear-teeth mesh in the wire coils in contact like a rack and pinion sending and receiving coils, though, of course, the dimensions will be different for each case. The slider is formed like a gear wheel. The coil-turns serve as a rack, so that the net effect is.an almost frictionless direct contact, turn by turn with the coil. Where an ordinary slider makes only line contact by friction with the wire, this slider contacts a larger portion of the conductor. The wire is wound in screw-threads cut in a lathe into a composition non-warping tube, so that the turns can be accurately spaced. The wheel is cut from copper or brass to match the coil pitch, though the less exacting builder may use an old alarm- clock wheel or even a knurled binding- post. A pitch of 20 with corresponding _ wheel about %% in. in diameter has been found best for receiving coils. For the inner coil of a loose coupler the wheel is arranged to contact through a slit in the tube from the inside, so that the secondary may be moved in or out of the primary. Of course a plain wheel may be sub- stituted, but all of the good qualities out- Amateur Electrician LW And Wireless Operator lined will not be retained. This simple improvement constitutes an important betterment of this class of variable coils. This, of course, is equally suited to rheo- stats and other helical coils. There is substantially no wear on the wire and consequently no short-circuiting of turns by burrs carried over by the erosion of a friction slider —P. E. EDELMAN. Fastening Binding-Posts on the * Ends of Heavy Wire XAKE an empty rifle or revolver shell, about a 32-caliber, and through the closed end punch a hole large enough to receive the screw of a binding-post. File the screw off short enough and then push it through the open end of the shell, through the hole in the closed end, and screw the parts of the binding-post in place. Clean the inside of the shell and fill with solder. Insert the end of the wire and heat well over a blow-torch flame. Use soldering flux. How to Make a Ten-Ampere Key for Wireless HE contacts of the ordinary telegraph- key are not large enough to stand the current of a fair-sized transformer. But by adding the contacts as shown in the illustration any telegraph-key can be made of 1¢-in. sheet brass bent as shown. The end of the stand A is drilled and tapped for a 5 /32-in. brass ad- justing rod, B, which is provided witha lock- nut and adjusting handle. At the end of the screw asmall piece of silver—a dime willdo— is soldered and another issoldered to therear end of the key lever, as shown, with a hard solder. The upright A should be provided with a binding-post, as the old contacts of the key are not used.—EDWARD JASPER. _ ADJUSTING HANDLE 7 LOCK NUT 8 DIME CONTAGTS Ordinary telegraph-key with silver contacts 147 148 Popular Science Monthly Making Photo-Electric Cells to Work from a Light HE generating of an electric current by the action of heat upon a point of contact of two dissimilar metals, ie ag cee os wath gal) ae fe Ate AT | y ia | a i ol eeu | eee: eee Fhe ee & 5 fH ’s hes 5 General principles of the thermo-electricity which is set up by difference in temperature generally recognized by the term ‘“‘ther- mo-electricity,”’ is perhaps well known to those engaged in experiments in the field of electricity. The action and general construction of a thermo-electric or “‘heat’’ battery, is shown in Fig. 1, in which the points designated by A are strips of copper connected in series at the contact points with the iron strips B, which are the alternate junctions, the latter being heated or placed in boiling water, while the former are kept cool by immersion in ice water. The arrows indicate the direction of the current, which increases in proportion to the number of pairs of junctions and the difference in temperature of the hot and cold contact points. That light also possesses this mys- terious power of producing an electric current is known to but a few investiga- tors, and perhaps if more widely known would result in a practical research that would add much to our knowledge, and might lead to the’solution of the problem as to the nature of electricity. This light method of producing electricity is from what is called photo-electric cells. A simple photo-electric cell may be constructed by forming two cylinders of tin-foil of such size that one may be placed inside the other, the inner tin- foil being wrapped in blotting paper to shade it from the light. The two cylin- ders are then immersed in plain water and connected with a sensitive galvanom- eter consisting of a compass placed over a small coil of insulated wire, as shown at C, Fig. 2. Ordinary sunlight or the light from burning magnesium is allowed to fall on the outer cylinder D, a current of electricity being set up as shown by the deflection of the compass needle, and flowing from the shaded cylinder to the “light” cylinder. An interesting and efficient cell of this type has been constructed by Saur and termed the “impulsion cell.” As shown at Fig. 3, it consists of a solution of common salt, copper sulphate and water. A plate of silver sulphide, EZ, is immersed in this solution and also a porous pot, fF, containing a little mercury in the bottom into which dips a sheet of platinum G. The glass vessel is then placed in an opaque box as in Fig. 4, which should be closed to exclude all light. On connecting the circuit through a galvanometer a weak current will be set up as shown by the needle. When, however, one side of the box container is opened and light from the sun allowed to fall on the silver plate, there will be noticed a considerable in- crease of the current strength, which will decrease with the mere passing of a cloud over the face of the sun, thus demon- A simple photo-electric cell formed of two cylinders of tinfoil one inside of the other strating the sensitiveness of the cell. This cell may be put to practical appli- cation as a “‘light-recorder’”’ by connect- ing through a tracing point running ona strip of lined paper. It may be of interest to note another “‘light’’ cell perfected by Riggollot who used copper oxide plates, 1 in. long by 4% in. wide. The plates were dyed with malachite green which seemed to in- ee Popular Science Monthly crease the current strength as demon- strated by his many experiments in this field. On exposing one of the Zz = SME 2S SES CAEN Ge GALL at apdipee ees ona is | A L277 Khe / MSP —>* Ako’ LASS LEIP PE LATE An impulsion cell which has a solu- tion of salt, sulphate copper and water plates to a strong light a current was generated, proportional to the intensity and varying with the distance of the light. The peculiar fact was also noticed that on running the exposed plate along the spectrum, that is, exposing it to all the colors of the rainbow, it was positive at the red end but changed to negative as it neared the violet. As yet, there has been no plausible explanation as to the mysterious rela- tions between heat, light and electricity, yet the phenomena exhibited by these iar cells may be more clearly 4 understood by the application of Dr. ____See’s new theory of light which states, that: “The whole theory of ether is abandoned as having no existence, light being caused by electrically charged particles, shaped like eggs, revolving about their axes, and that electricity itself cannot be separated from matter, but always carries matter along with the currents.” There is a fascination about research i - work in this comparatively new field of photo-electricity which should entice experimenter who delights in solving Scientific problems; for the solution as to the nature of electricity will probably be found sooner or later by the simple appli- cation and arrangement of the facts gleaned from a patient scientific research _ into fields, which as someone has said, _ “makes thinner in places, the boundary _ between the known and the unknown.” —A. R. MaAcPHERsON. 149 Inexpensive Stranded Aerial Wire Made of Small Copper Wires PPER wires may easily be twisted together for antenna conductors by using a hand brace or drill. One end of the strand of wires is fastened to a post or other support, the other end is secured in the chuck of the brace or even merely bound to it with a piece of strong wire. When the strand is stretched out straight and kept a little taut, one turn of the brace for each foot of the total length of the strand will produce an evenly twisted cable—E. F, Koxe. An Electric Alarm Signal for the Fisherman ATCHING a fish-line set in the ice, on a bitter cold day is disagree- able, so that the following plan will be welcome. The usual “tip-ups’” and “jumping-jacks” serve their purpose nicely, but a more elaborate and interest- ing device is an electrical signal. A complete outfit may be carried in a box, as easily as a tackle. An ordinary. electric door-bell is mounted in a box, and put in circuit with a three-cell flashlight battery. Two strips of spring brass are tacked to the outside of the case. These are also connected, one with a terminal of the battery and the other with a binding-post on the bell. The strips of brass are bent in such a way that a slight pressure on one ee When a fish is hooked, the tug on the line causes the contact which rings the bell immediately brings it into contact with the other. The box is opened, and set near the hole where the fishing-line is led into the ice. One end of the string is tied to one of the brass strips, and as soon as a fish is ““hooked”’ he will tug at the string and bring the strips together, sounding the alarm until removed. 150 Estimating the Windings of the Electromagnet Coils T is frequently desirable to rewind electromagnetic coils to obtain more efficient windings, or to make and wind the coil complete. It is usually difficult to estimate coil-windings correctly, with- out dealing more or less with complicated technical formulae. The successful operation of every electromagnet depends upon the number of ampere-turns produced within the winding when a certain current is flowing through it. The value of this current is, of course, determined from the resistance of the coil and any of the apparatus that might be in circuit with it. For example, a certain electro- magnet is connected alone in a 4-volt circuit, the coil being wound with 500 turns of wire, giving a resistance of 10 ohms. By Ohm’s law, the current C equals .4 ampere. 500 X .4. = 200 ampere-turns, which rep- resents the strength or pulling power of the magnet. It may happen that this pulling power _ is not sufficient to produce the result. desired, in which case it can be increased by either the number of turns or the amount of current in the circuit. By using a larger size of wire, the number of turns may be increased and the resistance reduced, thereby allowing more current to flow, which means a decided increase in the effective ampere- turns. It is not always possible to do this, however, on account of the small winding space available. In this article we will consider only spools having round cores, these being the ones most generally used. The calculations would be simplified if it could be assumed that the convolutions of the wire were lying together, as if the wire were of square cross-section. Ex- perience has shown, however, that this is not the case. The condition more nearly approached is where the second and each succeeding layer of wire lie in the grooves formed by the preceding layers. To simplify matters, we will take the square of the diameter of the wire as the actual space occupied by each turn, which will be approximately correct and will give good results. The diameter of the insulated wire can be determined by taking the diameter of commercial bare wire and adding the Popular Science Monthly thickness of insulation, which varies with the manufacture. No fixed values can be given to cover all cases. A number of the leading manufacturers furnish handbooks or cards showing the average diameter over the insulation. The following table of thicknesses for different insulations will be found to give good results: COTTON SILK se B. &S. re Enamel Single | Double] Single | Double 0-10 | .007] .O14 se aoe 10-18 2005 | .O10 pte aes in Feet (in Feet) Meters) 35 147 45 50 210 64 75 315 : 96 100 420 128 125 525 160 150 630 192 The fundamental wavelength of a plain vertical antenna wire increases with its length difference in the aerials the shorter one™ should have more turns of coil connected © in series with it. This was, of course, to make the effective lengths of the two- antennas the same, so that they would | pe tuned to the same wavelength. Receiving Various Wavelengths _ With the senders and receivers limited in their activities to communication be- _ tween a single pair of stations, it is usually - mot necessary to provide for variation in 4 pe tuned wavelengths of either. That is U7” TUNING-COIL : MICROPHONE = 9 — ORY-CELL —=SS_ GROUND + FIG.3 A simple arrangement which has the detector in series between the antenna and ground why the simple arrangement of Fig. 2 in _ the December article could be used. When _ it is desired to receive from a large number of outside transmitters, all using different d wavelengths, it is necessary to provide apparatus whereby the effective length of z the aerial at the receiver may be varied to suit the incoming wavelength. A large number of arrangements may be used for ‘this: purpose. Some of them tune the _ receiver very sharply, or in other words make it respond energetically to a very closely restricted range of wavelengths ior each adjustment. Other sets of connec- ms are less critical in adjustment, but easier to handle. __ The simplest variable tuning instrument for use at the receiver is the so-called ‘single-slide tuner.’”’ This is merely an aductance coil with a sliding contact whereby the number of turns in circuit may _ be varied at will. It may be used in place _ of the tuning coil shown in Fig. 3, and will _ allow some latitude of adjustment, though _the tuning is very broad and unsatisfactory. mode of connection for the single- this gives og spe tuning and porte rang A still better tuning arrangement fuses : “double-slide tuner,’’ which has two ‘Variable contacts. In the catalogs of _manufacturers of radio apparatus there are ) to be found a large number of diagrams Popular Science Monthly 155 showing different ways to connect the double-slide tuner; but the best possible results are: to be secured from the arrange- ment of Fig. 5. One end of the coil is connected to ground, and one of the sliders to the antenna. The larger the amount of coil between the grounded end and this first slider, the longer the effective length of the aerial and the greater the wavelength for which it is tuned. The grounded end is also connected to one side of the blocking condenser described in the November article, and the other slider is connected with one terminal of the crystal-detector also illustrated in November. The tele- phone has one lead connected with ground, and the other joins the open sides of the detector and blocking-condenser. The test-buzzer, which is not shown in Fig. 5, is to be arranged as explained in the December article, so that the crystal-detector can be adjusted to its maximum sensitiveness without waiting for signals from outside stations. Operating the Variable Receiver In working the apparatus set up as in Fig. 5, the first step is to make sure that the detector is adjusted to a sensitive point, and that the connections are all secure and in good condition. Then the slider connect- ed to the detector is set at a position about half-way along the coil, and the antenna- slider is moved back and forth slowly along the length of the entire tuner. When a station within range starts to send, his 7 ANTENNA z LOADING-COIL hecatae =. ROUND Connecting the detector around the loading- coil produces a highly selective arrangement he ee BLOCKING=- CONDENSER 99 4 TELEPHONE FIG. 4 signals will be heard in the telephones; it will be noted that the dots and dashes are loudest with the antenna-slider at some particular setting. Leaving the antenna- slider at this point, the detector-slider is moved back and forth until the position giving the best signals is found. This is the tuned or approximately tuned adjustment of the receiver for the specific wavelength being received. 156 It often happens with double-slide tuners of this type that there are several positions for both sliders which give good signals for a single wavelength. Therefore it is a good plan to try several settings of the antenna-slider, varying the other contact at the same time; thus one can sometimes find a single pair of settings which give ANTENNA \K DETECTOR= CRYSTAL~ SLIDER DETECTOR - S— vd DOUBLE-SLIDE ere TUNER x = | 2 ae Table for learning the dots nec- + a essary to send a letter signal ‘ - The dots for each letter are ascertained — by numbering each with two numerals; first a numeral indicating the group to which the letter belongs and second its position in that group. Thus A is I-I, — B is 1-2, C is 1-3, and so on, to F, 1-6. 4 The second group is numbered similarly _ from one to six except that-the number in-_ dicating the group is 2 instead of 1. The second letter in the fifth group, Z, is 5-2. After a person has written out the alpha- bet in this manner and set it before him, he can with very little practice spell out any. message he may desire to send. For ex- ample, the word “‘radio’’ would be: 3 dots, short pause, 6 dots (R), longer pause; 1 dot, pause, 1 dot (A), longer pause; 1 dot, pause, 4 dots (D), longer pause; 2 dots, pause, 3 dots (I), longer pause; 3 dots, pause, 3 dots (QO). P Amateur wireless operators, boy scouts, miners in distress, mariners, ignorant of the Morse code will find this simple code useful. For sending numerals, the 10 digits are expressed by dots corresponding to their value, naught being indicated by 3-3. What Radio Readers Want to Know ~ A1500-mile Receiving Aerial; pate Re Variometer _ P.0.Pa, Baxley, asks _Q. 1. Will No. 14 iecthen wire give about as d results as copper wire in an aerial comprising r wires 100 ft. in length. This aerial is intended receiving purposes only, for distances of 1000 to 1500 miles from government and commercial - . ration: a. 1. util he nd. noticéable difference ia strength of signals received on aluminum wire from those heard with copper aerial. __ 2 2. My inductively coupled receiving tuner in form has a maximum wavelength adjust- at of 1500 meters; could I make it adjustable to > meters by means of a variometer instead of the egulation type of loading coil? A. 2. If the variometer is designed to have a sufficiently large maximum value of inductance it will serve in every way as well as the simple cylindri- loading coil. In addition it will have the ad- atage of continuous adjustment of inductance, as ontrasted to tuning in steps. . The best possible an, however, would be to use a small variometer to allow close adjustment between the steps of in your loading coil or transformer jrimary, and to make the large jump of inductance aeeded to go from 1500 to 2500 meters by use of a loading coil of the plain type, with a few large steps . QD Je off. Po nuctance Multiple-Layer Tuners for Large Value of Inductance et. S. D., Fort Worth, Tex., writes: ) @. 1. Isit essential that the loading coils used in ) the undamped wave audion circuits be wound in a le layer on a very long spark to obtain the um degree of efficiency, or can they be wound wimare than one layer on a core of shor g L Multi-layered coils have proven as efficient '@s the single-layer coil of great length provided the recaution is taken to separate the layers of the g from \% in. to % in. By this method a il of very small dimensions can be constructed for | 4 - large value of inductance. In fact a coil out 4) in. in diameter and 6 in. in. length com- rising four layers of wire equals the inductance ue of another coil 30 in. in length, 6 in. in e ‘Where can I obtain cardboard tubes as a SUI DO Sed the windings of an inductively coupled ‘)/fecetving tuner to be 6 in. in diameter and 7 in. in diameter respectively ? A. 2. Tubing of these dimensions can be obtained ‘from Ware & Company, Watt St., New York City. i r Interesting and Instructive Questions and Answers Charging an 800-foot Aerial with a Spark Coil; Intensifying Transformer Dr. F. C. S., Gwinner, N. Dakota: Q.1. Will a 4 in. spark coil charge an aerial 800 ft. long, one wire, for sending; or what is the longest aerial it will charge regardless of wavelength? A. 1. The longer the aerial wire the larger its capacity, and the more coulombs (quantity) of electricity are necessary to charge it to a given voltage. The output of a spark-coil depends upon so many other constants than its sparking length, especially when the coil is connected with a capacity such as an aerial, that it is impossible to answer your question specifically. The coil should charge the wire you mention to some potential high enough to produce a spark, but better results would doubtless be obtained with a shorter wire. Q. 2. Can I use No. 36 wire which I have on hand, in building an intensifying transformer for use between two audions which are to be operated from the same battery? A. 2. Yes, No. 36 wire can be used for the intensifying transformer windings. Make a core I in. in diameter by 6 in. long, and fit over it two spools having separation of 1 in. between flanges 4 in. in diameter. Wind each spool full of No. 36 double covered magnet wire, and immerse them in melted paraffin to fill the spaces and prevent damage by moisture. Slip the two filled spools over the core and place them side by side at the center. Either may be used as a primary coil, connected with the plate circuit of the first audion; the other then becomes the secondary and is connected with the grid circuit of the second audion. It is sometimes advantageous to connect only one terminal of the secondary with the grid of the second audion, leaving the other side of the coil open circuited. Which side to connect must be found by trial. Dimensions of a Transmitting Condenser and Coils S. F., Whitewater, Wis., inquires: Q. 1. Please state the dimensions for a mica dielectric condenser for a 4% K.W. transformer having a potential of 13,200 volts. A. 1. We caution you not to construct a mica condenser unless you can obtain an extremely good grade of mica and have the necessary apparatus for impregnating the plates with an insulating com- pound. You would do better to purchase copper- plated Leyden jars. Assuming that your set is to be operated at the wavelength of 200 meters the condenser should have a capacity of about .008 microfarads. An oil-plate condenser for this purpose may T5450 160 consist of 12 plates of glass 8 in. by ro in., covered with tinfoil 6 in. by 8 in. Twelve of these plates connected in parallel will afford the required value of capacity. The foil may be attached to the plates by means of melted beeswax. The plates should be % in. in thickness. - Q. 2. Will the following described oscillation Senetecines be suitable for this set? The primary consists of six turns of 5/16 in. edgewise-wound copper strip 5 in. in diameter while the secondary has eight turns of 4% in. edgewise-wound copper strip 714 in. in diameter. How far apart should the turns be spaced? A. 2.. Provided the turns are spaced % in. the transformer will prove entirely satisfactory for operation at the wavelength of 200 meters. Requirements for License E. M. K., South Amboy, N. J., inquires: Q. 1. What are the requirements for securing a license for an amateur sending station? A. 1. To secure a license for an amateur sending station, the applicant must first possess an amateur first or second-grade license. The examination for this certificate is taken at the U. S. Navy Yard, Brooklyn, N. Y. To obtain an amateur first grade certificate the applicant must have a sufficient knowledge of the adjustment and operation of the apparatus which he wishes to operate and of the. regulations of the International Convention of Acts of Congress in so far as they relate to interference with other radio communication and impose certain duties on all grades of operators. The applicant must be able to transmit and receive in the Inter- national Morse Code at a speed sufficient to enable him to recognize distance calls or the official keep-out signals. A speed of at least five words per minute, five letters to the word, must be obtained. After this license has been secured, you must then communicate with the Government Radio Inspector, Custom House, Bowling Green, New York City, who will send you an application blank to be filled out and in which is fully stated the purpose of the station, the character of the apparatus, the size of the aerial, etc. If satisfactory and in accordance with the requirements for amateur stations, a licensed certificate will be given and a call letter assigned in due time. Q 2. What are the requirements for a com- mercial license? A. 2. To qualify-for a commercial first-grade license the applicant must pass a satisfactory ex- amination in the adjustment, operation, and care of commercial wireless telegraph apparatus, including the correction of faults and changes from one wave- length to another. He must be able to transmit and receive in International Morse Code at a speed of at least twenty words per minute. He must have complete knowledge of the use and care of storage batteries or other auxiliary apparatus. He must be fully informed on the International Regulations in force applying to radio communication. He must also know the requirements of the Act of August 13th, 1912. Popular Science Monthly Dimensions of a Short Wave Transmitter R. P. P., Newark, N. J., inquires: Q. 1. Please give the dimensions for an oscillation transformer and condenser to be used with a 44 K.W. set and an antenna having a wavelength of 170 meters. A.1. The primary winding of the oscillation transformer may consist of four turns of 3/16 in. copper tubing or No. 6 D.B.R.C. wire wound on a — form ro in. in diameter, the turns being spaced 1 in, _ apart. The corresponding secondary winding may | be 8 in. in diameter and comprise Io turns of the same tubing or wire spaced 34 in. apart. The condenser should have a capacity of ook : microfarads and for this you require 12 glass plates 3 % in. in thickness, with other dimensions 8 in. by : 10 in. covered on both sides with tinfoil 6 in. by 8 in. — These plates should all be connected in paraltel and : then immersed in oil. Long Distance Receptions from Germany. A. T. Valparaiso, Ind., inquires: Q.1. Is an aerial 200 ft. in length 80 ft. in height suitable for the reception of undamped wave stations located in Germany? a A.1. Yes, provided a supersensitive receiving set is employed. 3 Q. 2. Can I use a sliding wire tikker for this purpose? A. 2. To collect enough energy for these distant stations to make audible the signals on tikker, it would require an antenna of enormo proportions such as used at the large transatlantic — and transpacific stations. Some form of the audion oscillating circuit is required to receive foreign ; stations on amateur aerials. 7 Q. 3. Please give a circuit diagram for a long ‘ distance receiving set, and data for the construction 4 of the tuner. 4 A.3. You had better secure a copy of the November, 1915, issue or the April, 1916, issue of this” magazine ‘and note the articles on long distance receiving apparatus. Also in the book “How to Conduct a Radio Club” (on sale by the ok Department of this magazine) there is descri fully the circuits of a long distance receiving set with the complete dimensions for all the coils. * _ Q.4. This set is to be used in eastern Pennsy vania in a mountainous district. Will the mountains interfere with the workings of the apparatus? ee A. 4. Generally, no. Mountains seem to have the most severe effect when they are located near to the transmitting station rather than to th receiving station. Licensing a Receiver P. T. P., Salem, Va., writes: Q. 1. Iam about to erect a receiving station and desire to know if it is necessary for me to inform the Radio Inspector. ie A. 1. The inspector need not be informed nor is Books Mean Success You can’t get on in the world unless you read —read the books which will make you more valu- able to those for whom you work. You don’t have to go to college. Edison never went to col- lege. But he has probably the finest library of technical books in this country. _ If you want helpful, practical books on elec- tricity, mechanics, mechanical engineering, wire- ay aeroplanes, sheet metal work, repairing, write to the Popular Science Monthly’s Readers’ Ser- “vice Bureau. Tell us in what subjects you are t Sitctected’ and we will compile a list of books, with their prices. We will send more than a mere price list. We will select out of a hundred or more titles the very book which, in our opinion, meets your requirements. Whenever you are at a loss for an inexpensive, _ practical book, or for information about books, a write to Popular Science Monthly’s Readers’ Service Bureau 239 Fourth Avenue, New York Rescuing: Fire Victims with a Safety Searchlight quipped with the new searchlights and smoke helmets carrying Members of a fire rescue-squad e The lamp is fastened on with suspender straps out bodies from the hold of a ship. 162 Popular Science Monthly 239 Fourth Avenue, New York City : | $1.50 No? | February, 1917 een Safety Searchlights For Firemen Fire rescue operations simplified by the use of a new ‘ lamp which gives the fireman the free use of both hands WT is obvious to anyone familiar with fire-fighting that a lighting equipment -. Which will enable the fireman to see his way in a gas and smoke-filled room and at the same time allow him a free and un- obstructed use of the hands and arms would meet with instant-iavor. At the present _ time the fireman uses a simple oil- * burning torch or acetylene lamp » which he carries in his hand. His = ~ efficiency as a fire-fighter is, of course, greatly lessened, since he has the free use of only one x _ hand. ~ A new searchlight tested * by..the Cincinnati fire de- * Gperimest and now adopted _a part of the standard cent of that depart- _ ment, may yet supplant the > torch and acetylene lamp. ~ The lamp is strapped on the ‘back of a fireman. The burner or lamp extends _ above the fireman’s head, ‘and an extension allows of adjustment, so that the fireman can direct the rays of the lamp in any direction desired. The device weighs thirty-two pounds. _ Thesearchlight is intended to be of greatest service in fires where rescue work has to be carried on. The fire- man equipped with it has his arms free to use as he wishes. In entering a burn- ing building where the dense smoke makes it impossible to use a small light, the new lamp would be of great as- sistance. It cuts a clean swath of light through the densest smoke, permitting the members of a rescue squad to carry on their work with safety and dispatch. The drawing on the opposite page The new lamp is fastened on the back of a fireman with a strap resembling suspenders. The burner extends above his head vividly illustrates the use of the new lamp by firemen carrying on rescue operations in the hold of a ship where the smoke and gases are particularly thick. Fortunately, the hold is high enough to permit the fire- men to work with the new lamps without bending their backs to clear obstructions. The fireman in the foreground can thus climb the ladder witha suf- ’ focated boy in his arms—some- thing which would be extremely difficult to do were he obliged to hold on to a hand lamp at the same time. The principal objection to the lamp is found in its excessive height. In New York, for instance, most fires of a gaseous and smoky nature occur in cellars with ceilings so low that the firemen are obliged to crawl instead of walk in them. This is especially true of sub-cellars, which are so low as to eliminate at once the use of such lamps unless the wearers are willing to undergo the inconvenience of constantly bending their backs. On-the other hand, it is said that no lighting ap- paratus ever will take the place of the hand lamp. for the reason that it is, after all, the most convenient means of directing a ray of light to a desired spot in a minimum of time. True, the new lamp can be focussed in any direction, but. not until the man wearing it reaches behind his head and adjusts the arm. Another objection to the ‘new lamp is that falling objects could easily sever the lamp from its stem. 162 Suppose New York’s Harbor Were Drained It would look like the picture below and show the deep channels dredged for great trans-atlantic steamships HE. ac- com- . panying illustration shows how New York Harbor and Vitewity would look if all water were drained off. The deep channel of the Hudson River is shown and the exact shore line of New Jersey and lower New York is vivid- ly outlined. But the most interesting single feature is the loca- tion 28a shape of Am- brose Chan- nel, which is the largest ar- tificial harbor entrance in the world. It ninety-five thousand dol- guarding the channel to prevent it from being clogged by il- legal dump- ing. Because the dumping scows must pass far out t6: . S¢ a5.ce@ dump their loads of rock and debris there is a ' great tempta- tion on the part of dis- honest cap- amount of dirt and rock dumped at sea during the past twenty- five years would build is through this seventy pyra- channel that mids the size the great of the great ocean liners pyramid o must pass to Cheops in and from New Egypt. The York. increase in Ambrose The three black lines at the extreme top represent Williams- late years has Channel is seven and one-half miles long, two thousand feet wide, and forty feet deep at mean low water. Sixty-six million cubic yards of material were removed in making the channel, and the cost to the Government was four and one-half million dollars. The cost of upkeep is even more astound- ing. Each year the Government spends burg, Manhattan and Brooklyn bridges. below them is Governor’s Island and the Statue of Liberty is on one of the little islands to the left. the stretch of land lying directly below Gravesend Bay The black spot been four- teen million cubic yards. Is it any won- der, then, that the Government is so vigilant in its patrol that it forbids tugboat captains to dump the ashes from their own engines in Ambrose Charinel? To theindividual such an injunction seems arbitrary; but am aggregate of all the ashes from all the tugboats that enter the harbor would present a formidable problem. Coney Island is 164 lars alone in tains to dump | wherever con- venient. For instance, the Ce ee ee ee a ee | | j | . | Popular Science Monthly 165 What the First Aerial Bombs Were Made Of T may be remembered that Garros came to the United States in 1911 and amazed vast audiences by his audacious flights. From here he went to Mexico to entertain the populace there. It occurred to him on arriving that, since fighting seemed to be the favorite pastime of his Latin brethren, he would making a lasting “‘hit’’ with them if he could only arrange for an aerial sham-battle. To his good luck, he found = , the general in command of the army, then Mas. ANE | besosix in Mexico City, a willing listener. Accord- — ingly, one day he was seen flying over the Mexican batteries, armed with baskets of juicy oranges that the quartermaster had given him. Suddenly the batteries opened fire and sent shot after shot after him. The immense crowd became wildly enthu- siastic, although they knew, of course;that only blank cartridges were being used. Garros then started to let go the oranges upon the artillerymen. To his surprise al- most immediately they began to scatter in every direction. The quartermaster had not realized that a juicy orange dropped from so great a height would rival a small bomb. The first aerial fight unquestiona- An incisor tooth covered with a solidified bly was won by bombs.of ripened oranges. matter which has eaten the gum away but = i ES has preserved the tooth from bacteria A Tree Root _ Resembles A Peculiar Disease of the Teeth Which a Young Deer Disables and Yet Preserves Them HILE clearing the way through a Wisconsin forest for a railroad, a construction gang pulled up a curious bit of tree root. One of the men saw a resemblance in it to a young deer, and accordingly took it back with him to camp. Merely by cutting away the surplus branches, the root was formed into a fairly good-look- ing deer; that is, if such matters asa bandy- leg and full-grown horns may be overlooked as desirable members of a very young deer. The eyes, nose and ears were formed by the knots when the branches were cut away. The deer stands three HE peculiar infection which dentists call “salivary calculus’’ will, if left to itself, cause a person to lose his entire set of teeth. Yet when this » happens, the teeth themselves will B> often be in a perfect state of > preservation. The organic and inorganic matter, derived from the saliva in the mouth, solidifies and forms a_ hard deposit upon the teeth. The mechanical irritation of the deposit causes the gums to become exposed to chemical deteriora- tion of the salivary de- posit. The deposit then absorbs the gum tissue and interferes with the building up processes of the bony roots, so that the teeth finally become completely exposed and ° ‘ Woodsmen in a Wisconsin forest found feet high and is a this curious tree-trunk which they must drop out because prized curiosity. imagined resembles a very young deer of their lack of support. The Stained-Glass Attitudes of Saints and = | | a | © Press Illus. Serv. The photograph above shows the various stages in the making of a stained-glass window. On the table is a small sketch of the window first submitted to. the customer. The worker is standing in front of the large outlined drawing from which he secures his patterns. At the left is the window itself partialiy completed Painting a small face on a slab of glass which has been cut to fit into a large window. The artist first makes a rough sketch of the figures. This sketch is later removed and a more accurate one, made in careful proportion, is substituted. The glass then passes into the hands of the artist who works with paint and brush Angels and How They Are Created Pieces of painted glass being fired in a kiln. The glass remains in the kiln for several hours and if the exact shade is not obtained it must be fired again. This is an antique method but no modern way has superseded it At right above: When each tiny part of the pattern has been covered with a corresponding piece of colored glass, the pieces are cemented into place with lead and the com- pleted pattern is then very carefully polished At right: The central panel is a large stained-glass window. This panel appears in its finishe immediately below shows an Putting the final touches on the panel shown above. The artist is working with the panel attached to the window in order to judge the light effects. At the right of the panel is a chart upon which is accurately out- lined the various parts which go to make up the finished piece. The artist constantly refers to this in painting her figures d form. The photograph artist working on it At left: Fastening the small pieces of stained glass to the plain glass with gum. This is a slow and laborious method, but it gives the window- maker the first definite idea of what his window will look like. Later the pieces of stained-glass are leaded in Cable Laying as the Signal Corps Does It PL One of the important voca- tions taught in the Signal Corps school is cable laying. Above is shown a shore-land- ing party of the cableship Burnside towing the cable to shore in shallow water. Once on shore a trench is dug and the cable is led to the station At left: A Signal Corps cable- . man securing the cable before | casting from the grapnel or anchor. Should the cable part from its moorings it would not. only necessitate great expense in an attempt to recover it but the chances of so doing would be remote i How a cable looks when its covering is removed. To give it strength each cable is composed of a large number of small steel threads wound and twisted and sometimes inter- woven. No cable is stronger than any one of its threads. Were one thread to break, additional strain would fall on threads adjacent to it causing them to break and finally de- stroying the whole structure of the cable ae ee fiat ss sii BOE A ls aati i i Wl Fe le "Se Alyse 3 Straw Umbrellas for Chrysanthemums Aynvaq oy} Burfoysop sny3 ‘youyiq spejed ax MBIYS YIM sumMuUsyjUBshiys JO sMo1 om} are SISLINg[NONJO0Yy Yous PezZtlAlO 94} Jnoysnosy} sJ0Avy OUT BuNads "ynoqe 91331] 12 1} jo sd 9ya suin3 WOT smoys YydeiZoj0yd sy ‘UUNn{Ne JO SsOIy JUoNbasy 9yy wos Wey} 3993010 ©} se]ferquNn "H Burjoejsed ut aaeo epyuyur Suryez 41 Burmois ul ydepe Ajreinonsed oY OM FEYI'P[IOM sy} Jo syed ut UdAd ‘uOSvaS GuUIngne sy} SuLimp si9aMoy jo JOMOY 94} SIRT "ppiom sey ‘Astep ploy ayduns oy} JO UISNOS 4suy [NyQNwveq ApJueTTLIG ‘31q yeoI8 oy} ‘unt uoy UBSAIYS sy 4 ti, pent Pa. seg First the White-hot, Flowing Metal, Then the Mold, A ninety-ton steel crankshaft for an electric power-house engine loaded on a pair of big gun trucks. Compare this with the automobile crankshaft from a sixty-horsepower motor. Tke bolts are to secure the flywheel in place Below: Rock crusher weighing 480,000 pounds, capable of crushing rocks as large as pianos at the rate of a thousand tons a min- ute. It is made almost wholly of steel castings Below: Connecting rod for a large steel-mill engine. Note the size of the nuts on the bolts in the end where the man stands. The connecting rod of a sixty-horsepower auto- mobile is shorter than the crank-pin bearing Below. A flywheel weighing 120 tons which is nearly thirty feetin diameter. It wasturned and made round and true in a great pit lathe. It is mounted on a 90-ton crankshaft and Lastly the Iron Monsters From the Mold A ponderous bevel gear nearly fifteen feet in diameter. Note the accuracy of the measure- ments as compared with the hugeness of the casting. It weighs exactly 32,000 pounds At right: A ten-foot “‘ butter- fly” valve large enough for a limousine to drive through. The gate is swung by means of an electric motor which operates on powerful gearing DE SE tS trellis a ll ai oe oy ——— ee, : 100 7“ sieatitntncrreinnne Cast steel “lateral”? or branch joint for a huge pipe line, loaded on a special car built without a floor so that the casting would clear bridges, tunnels and other railway obstructions encountered Below: The bottom of an en- gine bed-plate weighing 86 tons, cast in a single piece. It is loaded on a steel flat-car built especially for such heavy burdens, ordinary railroad rolling stock being too light One of the Strangest Natural Freaks—A White Negro The old man in the photograph is an albino Bush Negro. His skin is dead white and his eyes are pink, Although nearly blind he is an expert boatman and woodsman. His little grandson, who was included in the photograph for the sake of affording a vivid comparison, is jet black . 172 © 1S) WY ig ee pant oF ine] frome op i cD) =) vo es) i) On fe ) Cy ine) & f. ov + Q, Ww pike 'S) Me o pale} eo © & — eul] 211M pusBliaAo ue Aq sjeyideo uvodoing jueiodut J9y}0 pue eh I 3 I 2 persol}Ig~ YIM uo BUIYSeA, Aull 07 ‘paemoe «s ‘18 gi Std Meg cue Pekin yafoid pjoq oy} steer astm saddoo JO ayows a8ny e& jo Burpuy ax} pus A Pps dh Je shh 8 ath eawioit sty A pe es cle jo sofdjousd 9914} 94} SOUIQUIOD IJ = “OggT UI Aapyng JpugjOD Aq pouopueqe sajod pue o41M maria 3 I I q ding TBrIquINjoD YsHUg ut ‘Aspe, s9Argy Josey 24} Ul 93BB][INB[aF] 94} Jo UOAUeD dy} sso.19e a3pisq uorsuodsns aibyan y Building New Cities of Demountable Houses on The period of reconstruc- tion in the devastated and depopulated sections of France was under way when the smoke of battle was stillin the air. To-day the ruins of villages cen- turies old serve as_ the foundations for newer vil- lages of light frame build- ings and demountable houses. The English So- ciety of ‘The Friends” has undertaken this relief work of supplying home- ~» less French families with the ready-cut lumber to build their temporary homes. At left is shown a ruin under investiga- tion. The agent will de- cide whether the walls that are standing may be used again or whether an entirely new struc- ture will be necessary MKS sell | GG MMMM MMMM EEE Ce ee ee ee The height of good fortune—a horse to help! Here the builders have tiles with which to con- struct their wall. They have already begun to set up the framework for their future home TRA the Ruins of Ancient Villages Destroyed by War Above: A dwelling with the roof frame- work completed and some of the tile walls in. place. Since the wood comes in pieces al- ready cut to fit together it requires but little ingenuity to place it correctly. Six or eight men are required to set up each house A small dwelling house appears in the oval above. There are thousands of such temporary _ struc- tures in France at the present time. They can be quickly erected and, better still, quickly taken apart and removed to another place out of the danger zone. Moreover, when the time comes to build a permanent home the little portable house will furnish the timber Demountable houses of Sermaiz and sufficiently commodious to be co including household furnishings and € erected on the ruins of the ancient city. They are warm mfortable shelters for people whose earthly goods even clothes have been destroyed in a terrible war 1" Hats Are Smaller, Say the Milliners No, the lady above is not carrying the family washing on her head, and the lady below is not balancing a model of the Washington monument on her’s. The hats are Gothic turbans worn by the members of the Russian Ballet in their royal frolic ‘Till Eulenspiegel.” The two skyscraper hats are more than six feet high. What the white one lacks in height it makes up for in width 176 Glass Rock s Famous Looking Utah’ Surusdo oy} ul sommsy ueuNy dy} 930N ‘oCeys yudsold sz OWUT }I pdAreos puvs BZurmoyq pure pulp mou pue ‘dn poip pue Aeme poureip sdwems oy} ‘poawoydn sem jusul}UOD oY} sode 19,8] UT yeoid Ul Puno}; Useq 2ABY SUTeUTOI [ISSOJ 9s0Y4M so)1}doI sutAy jeoid oy} pue siojsuow oenbe otuesys pazsodsip yorymM uo pues [9Ad]-Bas ‘aSOOT ynq Suryjou sem yt our yey}, PY ‘Ose siedA UOTTIUI UdA_DS ‘apnqzyye JUssoid st MO[Sq J99J PUBSNOY} [B1J9AVS SEM AOL SIY ‘OJBUINSS .S}sIBo[oos IYII JI SOUBYSIP B YB ISNBO9q po]|eo Os *HOOY, sse[y-duryoory 0} SUIPIOIVy «‘SJOpUOM [BINjJeU JYeoId S,YeIF, JO oUO st ‘sAuI §s ‘ uns 9y} ApQQysiuiq 83 *}IOSOP B JO JSPIUT 9tf} UT St YOgy ssel4y-Buryooy "389M 943 JO SuOoIzsod ulezI99 ul UOIsnjold Photos Press Illus. Serv. Bottles, Bottles Everywhere, But Not A The basis of bottle glass is a siliceous sand, limestone and either sulphate or carbonate of soda. The photograph above shows the new mixture together with broken bottles being thrown into the furnace. Here it melts and forms a thick syrupy liquid which is later molded into the form of bottles The photograph below shows another kind of raw material used for bottle-making— “cullet.” It is a by-product of the glass furnaces and it is melted with the other raw materials. A combination of ‘‘cullet,’’ sand, soda ash and lime gives a white glass with a very slight greenish tone ’ At left: Placing the bottles in an oven for gradual cooling. After they have been formed in the mold the bottles cool quickly on the outside while they remain at a high temperature within. To produce a clear, strong bottle a twelve-hour cooling is necessary Drop to Drink Where They Are Made = ar " za : c - I NE oo et. f 4 ody ee ie Photos Press Illus. Sery. From -the mold the bottles, still At right above: The molten hot and soft, are transferred to a red hot table. The waiting boy grips the bottles with a special instrument and slides them into the annealing oven metal is poured into a mold which is swung under a compressed- air machine, like the one at the right. The air is forced into the mold where it blows out the where they are very slowly cooled glass, making it thin and smooth At right: While the bottle is getting its size and shape in the mold it is also getting its label. Here the man is cut- tine the monogram into the iron mold so that every finished bottle may have its label incorporated in its makeup After twelve hours of gradual cooling in different compartments of constantly lower temperature, the trays of bottles are taken out and the bottles are transferred to cases, ready to be shipped or stored The Taxidermist at Work Photos Press Illus. Serv. The taxidermist has some unpleasant work - to do in the preparation of the animal for mounting. The bony structure of the head must be carefully cleaned out and scraped free from all particles of flesh. Then it is washed in carbolic-acid.. The skin also must be care- fully scraped on the inside and “cured” Scraping the skeleton. After this is done the ? taxidermist works over it with tow or clay to : get the proper contour. When the worked- over skull has dried and set, the skin is drawn over it and. finished off so carefully that, when the hunter receives his trophy, it seems just as it appeared in its native haunts 180 eh tt a The greatest difficulty in mounting birds is to remove the skin without injuring the plumage. A bird is opened under the wing. After the body is removed the skin is painted inside with a preservative The Various Steps in Taxidermy Preparing to skin the deer’s head. Some- times a mold is prepared to take the place of the natural bones of the head. The skin is drawn over it and padded out with tow to correct any irregularities of contour Putting the finishing touches to the mounted speci- men. After setting up, the head is painted over with a solution of bichloride of mercury and methy]- ated spirits of wine to protect it against the ravages of insects, which are the greatest foe which the masters of the art of taxidermy have to combat TRI The Lesson Denmark Taught with Calves Have you heard of Dr. Bang? He freed Danish cattle of tuberculosis in a simple way, which New York City is now applying to poor, stricken children By A. M. Jungmann The babies at the Preventorium spend twenty-four hours in the open air. about four months, during which time every effort is made to correct the home conditions NE of the most important steps ever taken in preventive medicine is directly attributable to the care Denmark lavishes on her cows. Dr. Bang, a Danish veterinary, whose task it was to conserve cattle which were threatened with extermination through the ravages of tuberculosis, discovered that calves of tubercular parentage are not necessarily tubercular themselves. obyious. He simply took new-born calves away from their tuberculous mothers and fed them on sterilized. milk from a bottle. They grew up into healthy cows quite free from tuberculosis: Since then Denmark has adopted the Bang method of fighting tuberculosis and freed her. cattle from that dread disease. How Children Are Saved by the New Plan Dr.. Alfred F.. Hess is responsible for the application of Dr. Bang’s method to New York’s children. Until the Tuberculosis Preventorium for Children was opened at Farmingdale, New Jersey, we neglected to avail ourselves of the greatest weapon in His course was” They are kept for the warfare against tuberculosis—that of saving the children from the disease. Infants who become infected with tuber- culosis when under one year of age rarely recover, and those who contract the disease between the ages of one and two years have a very poor outlook. Young children who are cared for by a consumptive mother or — who are in daily or hourly contact with a — consumptive father, can scarcely be ex- pected to avoid infection. In conducting an investigation of one hundred and twenty ~ homes wherein one.or more of the adult — members of the family were suffering from ~ Dr. Hess found forty-two — Without exaggeration, that means forty-two ine no tuberculosis, infants under two years of age. doomed to succumb from tuberculosis. many of the one-hundred and twenty homes two or more infants were exposed. to it: Instead of adopting Bang’s method, § why not send away the tubercular member ~ of the family? That is not always practica- ble. A mother cannot be spared from the household, for the very reason that she has an infant to care for as well as other chil- 120 a Popular Science Monthly dren. A father, though suffering from ‘tuberculosis, is usually the bread-winner. Therefore, he can not be sent away. It was to meet just such conditions that the Farmingdale Preventorium was built, to provide a place to accommodate young children in whose homes tuberculosis con- stituted a menace to their health. The institution was organized primarily with a view toward building up underfed, poorly- nourished-children, who had. been exposed to tuberculosis or. who had contracted it, but who were in such early stages of the disease that it might be eradicated. Dr. Herman Biggs has estimated that there are forty thousand of these unfortunate - children in New York City. The Farmingdale-Preventorium accom- modates approximately two hundred chil- _ dren, who are kept there for an average of - about four months, so that the institution provides for six hundred children in a year. It is situated in the sandy pine belt of New Jersey; where the air is particularly life-giving. The children have a fine play- ground of one hundred and seventy acres. On entering the Preventorium each child is quarantined for three weeks in order to 183 prevent infection of the other residents. Discharged from quarantine, he is assigned to one of the open-air shacks, each of which accommodates .thirty-two children. Here he finds open-air sleeping quarters. Next he goes to the open-air school and enters the class for which his city schooling has fitted him. For the first time in his life, perhaps, he is given good, wholesome food, and all he can eat of it. Twenty- four hours a day he spends in the open air, pleasant surroundings, room and sunshine in contrast to the crowded, dark tenement. No wonder he picks up. The average gain is about seven pounds, which represents fif- teen per cent of the average body weight. Teaching School in the Open Air As children are accepted up to the age of fourteen years, school instruction has been provided for them that they may not be behind in their studies when they return to the city. Ten hours a week of school work keep them up to their grade. While the children are at the Prevento- rium, every effort is made to improve the condition of their homes in order that their improvement may be permanent. wath wig.» mia |. ay) s i : | ~ Children are accepted at the Preventorium up to fourteen years of age so that school in- Struction must be provided. Ten hoursof school work a week are sufficient to keep the children up to their grade. The curriculum is the same as in the city schools 184 Popular Science Monthly The Popularity of Liquid- Measuring Pumps poe great amount of gas- oline consumed as a motor fuel has been respon- sible for the wide use of the liquid-measuring pump. In Greater New York alone there are seven thousand measuring pumps in use. There are thirty-nine firms engaged in making them at the present time. Briefly described, a measur- ing pump is a pump adapted ee for the measurement of fluids The steam engine is of the two-cylinder locomotive type with in definite quantities by vol- slide valves. It is controlled by a small switch and lever ume. In many instances the Substituting Steam for Gasoline pump itself is the measuring device, and in = KEROSENE TAN IN- REA gf COMBUSTION ~~ CHAMBE in Automobiles other types the pump is only used to fill a — ASOLINE is high. Next year its price measuring chamber such as a pail or can. may be even higher. Herein lie the The ordinary piston-pump discharges a possibilities of the new steam-driven auto- Volume of liquid equal to the space volume mobile shown on this page. Like an ordi- generated by the piston in its travel. The nary gasoline car in appearance, the new Pumps may discharge only on the upstroke steamer and its power plant eliminate the or on both the up and down strokes. clutch and gearset, thus making for easy . driving. The car is controlled by a small a . Quantity switch and throttle lever aside from the usual 2 f functions of steering and braking. It is said that the car can run 1,400 miles without replenishing its water supply and that one gallon of lubricating oil will last for 8,000 miles. Mechanically, the power plant of the car consists of a kerosene-fired boiler, a.steam condenser and a two-cylinder double-acting steam engine. The water is pumped from a storage tank beneath the driver’s seat to the boiler placed under the hood. The water is then heated and turned into steam by means of a kerosene-burner below the boiler. The kerosene supply is piped from a tank at the rear of the car. It is ignited by means of an electric hot point controlled from the switch in the driver’s cab. The air with which the burning kerosene must combine is automatically supplied in the proper ratio by means of an electrically-driven blower. From the boiler the steam is carried aft to the steam engine which is mounted in a unit with the rear axle, driving the wheels direct. The exhausted steam is then carried back to the condenser, which takes - the place of the ordinary gasoline car radi-_ The pump delivers gasoline to the automobile ator. It is there turned back into heated with a minimum of waste and evaporation. water which is fed to the boiler, It is usually a measuring device in itself Ee eee ae Sree ew sone Te ey ee Dangling ’Twixt Earth and Sky from a Zeppelin The real pilot of a Zep- pelin is often a man suspended from the air- ship by a light steel cable nearly a mile long LMOST simul- : taneously with the first news “of the part played by ‘Zeppelin airships in the great war came rumors ‘that the Germans_ were using suspended cages or bash ets to act as observa- tion or steering cars. Later, - when a damaged Zeppelin ‘cast off its observation car, windlass and cable, the rumors _ became undisputed facts and _ the military authorities ceased to wonder how the big ships of _ the air could maneuver with such unerring precision. _ It was discovered that the real pilot was not the man behind the steering apparatus of the Zeppelin but a man lying prone on a tress at the bottom of the ob- vation car, with a _ telephone pped to his head, and with clock, sompass, light and other instruments Onveniently near at hand to enable to inform his comrades above of door in the top, and kept in constant communication with the men above. The telephone wire ran through the steel cable. The streamlike form of the car and its large fins at the rear enabled it to maintain a head-on course, making it possible for the observer to get a near view of the country below through celluloid windows, even though the Zeppelin was hidden in clouds and mists. On a stormy night it is thought that the observation car served as a great help in determining landing positions. - On the other hand, there are those who surmise that the man in the car dropped bombs. The main argument against this, however, is that the combined weight of the car and the bombs would prove too much of a strain for a light steel cable, if, indeed, it might not seriously interfere with the maneuvering of the | Zeppelin. The duty intrusted to him is im- « portant and dangerous enough without the ; added responsibility of dropping bombs. given time. means of five thousand feet entered the car a sliding trap | The Streamlike form of the car and its large fins at the rear enable it to maintain a head-on course, —" make it possible for the observer to get a near view of the country below through celluloid windows . | ne 185 The “Why” of a Golf Ball’s Flight The corrugations on a golf ball are not meant to beautify the ball; they determine its maximum carrying distance E are told in school that when a ball WV is thrown into the air it generally travels in only one kind of vertical path, the so-called parabolic, while its path as seen from above never diverts from a straight line. But that this is not exactly true during baseball games and during golf contests, may be confirmed by any “‘fan.”’ And when a long “‘brassie”’ drive is made, the golf ball may even rise upward during some part of its flight; so that its path can hardly be called para-- bolic. The schools would be exactly right in their statements if the effects of the air upon the spinning ball were not considered. But the fact is that if it were not for the influence of the air, a baseball could never be made to bewilder a batter nor a golf ball be made to ‘‘take” an obstructing “‘hazard.” When a pitcher desires the path of a base- ball to curve in a certain direction, he gives the ball as it leaves his hand a rapid spin in this same horizontal direction. The effects of the air upon the whirling ball are exactly those that would occur on a more pro- nounced scale if the ball were thrown through a long strip of water. The lacing A ee BASEBALL hve t 4 ar 2 ; = om SS oe | ripe pease alea merowet eae G5 ESTES TS tee DN PITCHER'S BOX The secret of a golf ball’s motion is to - be found in the churning of the air by the corrugations on the surface. of air packs against it and diverts it At right: A pitcher is able to “‘curve” the ball by making the ball churn the air. In a vacuum a body might be imagined to continue in a perfectly straight line Sen = ( A blanket AIR WHIRLS BALL CAVITY a on the ball churns the air in which it spins and carries the air around with it. about the ball’s center as the direction the ball itself is to turn, will be “packing” the air against its side, just as it would be doing with the water. Thus the air will be slightly compressed on that side, and as the ball skims along on-the blanket of air so formed, it naturally will be pushed away from it and be made to curve in its path. The corrugated marking on a golf ball ‘causes exactly the same phenomenon to take place. Here, however, the ball is rotated around a horizontal axis instead of a vertical axis as in the previous case. The golf stick hits the ball on its under side so that this side rotates upward in front of the ball as it spins through the air. In this way the air packs the blanket this time under- ’ neath the ball, and so tends to divert the ball upward. As a consequence, the ball, instead of continuously being forced down- ward is also slightly pushed in an upward direction by the blanket of air underneath. The golf ball is thus able to stay up in the air longer and the length of its flight is pro- portionally increased. see? 186 But the side which is turning in the same direction’ . a ee ee ee nl SON et are a ee eee 4 ees ey Pee ma ’ S ri ia f al -] ay ys kr Popular Science Monthly Combining the Telephone Receiver and Transmitter in One Instrument a method for combining the receiver and transmitter of a telephone into one instrument is the invention of an enterprising woman, Rosa D. Hatch, of Memphis, Tennessee. You speak and hear out of the same device. The receiver is mounted where the transmitter is generally placed on other telephones, while the trans- mitter is secured directly in front of the receiver. The receiver also differs from the ordinary in that it contains a horn large enough to throw the sound forward a distance of about twelve inches. The transmitter is directly in front of. the receiver but with its rear end towards it, so that there is little chance of the speaker’s voice repeating into his own receiver. When starting a con- versation, a button is pressed to connect the instruments with the telephone lines; and then, by talking and listening close up to the hood which encloses the instruments, the conversation may be carried on with privacy. In this way the operation of the telephone is made much more convenient, although the essential construction of each instru- ment has not been changed. A telephone with such features ought to find special favor with business men. RECEIVER HORN ‘g x = Holding the receiver to your ears is unnecessary in combination of telephone receiver and transmitter > = The fire used to burn the garbage also heats the surrounding water pipes A Water-Heating Garbage Burner Is Both Useful and Sanitary GARBAGE burner which also serves as a water-heater combines utility and sanitation. The garbage is placed in a chamber above the fire-box, the walls of which are the water pipes. This garbage burner is especially useful in the summer . when fires must be kindled to heat water. The burner is provided with either a front damper-door or a base on which the damper-door is located at the side where the damper-chain is out of the way when the fuel is inserted. 7 = The Origin of the Locomotive Whistle Is Associated with Butter and Eggs N a level crossing between Bag- worth and Thorton in England, on May 4, 1833, there occurred an ac- cident which gave us the locomotive x ~ #éwhistle. Stephenson’s locomotive “s) “Samson” crashed into a cart con- 4s taining fifty pounds of butter and eighty dozen eggs. Following the accident a meeting of the directors was called, at which Stephenson sug- gested that a whistle blown by steam be used to give warning of an ap- proaching train. 188 | © Brown & Dawson This family windmill tree must present an amazing spectacle when performing to the accompaniment of a stiff breeze at the approach of a big storm Thirteen Windmills Decorating One Pole NE windmill to a pole is considered a sufficiency, as a rule, but a Con- necticut boy has decorated a pole in his back yard with thirteen of them. Some of his designsare unique. For instance, there is the ocean liner with the 4 windmill on the “‘port”’ side 4 and another serving as the propeller. There is an aeroplane windmill among the number and an assortment of hu- man figures, including an original Indian that beggars description. The figure topping the pole looks to.be a half- cousin to those little fellows that adorn automobiles. The owner must be well-informed as to wind indications, Both the nest and the eggs are now solid rock. The orig- inal owner was a bird prob- ably about the size of a robin Popular Science Monthly Music From the Bowels of the Earth? Yes; in Texas HE south central portions of the United States abound in natural curiosities. Not only are there strange things to see, but mysterious sounds often cause the most unimpressionable and hardened traveler to avoid passing through certain localities alone, and especially after dark. Reverberations of the wind are the cause; but the mountaineers will tell you that the thundering footsteps of ‘‘Morgan— Morgan the raider, and Morgan’s ter- rible men’”’ may still be heard in calm- est weather in certain localities which they laid waste decades ago. A less eerie, but similar phenomenon of sound is heard in Texas, where there is what is known as the “singing well.”” In fine weather dulcet tones like the music from an Aeolian harp issue from the well. At times the sound is wonderfully clear and loud. Then it recedes, until it reaches the ear only faintly. These modulations occur regularly every few minutes. When an east wind blows, the water in the well is low and the musical sounds are faint; but a strong west wind will in- crease the volume of sound to a chorus. It is when the north wind blows, how- ever, that the music of the well is most weird and wild. A Wonderful Specimen of a Petrified Bird’s Nest ETRIFIED bird’s eggs have been found on several occasions, but as far as can be ascertained, it remained for a Washington State man to find both a group of petrified eggs and the petrified nest in which the eggs were origin- ally laid. The nest was imbedded in a _ rock formation in a cliff of the Grand Canyon, five hundred feet above the base. It must have been the nest of some bird about the size of a robin, and only one side of it—what is now the darker side—must have been exposed to the air. It is im- possible to estimate how long ago the eggs were laid. ———— ee a ee A Oe A PL ee reer S wey i ae _ ~(\ SIMPLE way to ascertain one’s eT _ Popular Science Monthly How Much Ought We to 189 Weigh Normally? ideal weight was told recently by Dr. Harvey G. Beck, of the Uni- versity of Maryland, in an address before the Los Angeles County Med- ical Association at Los Angeles, Cal. First, put down 110. Then multi- ply by 5% the number of inches by which one’s height exceeds five feet. Add the result of the multiplication to the original 110 and the sum is one’s “ideal weight.” Concrete Drinking Fountain of Novel Design HE drinking fountain shown in the illustration has several features that serve to make it distinctive. It is constructed of concrete and boulders, rough concrete blocks, and similar material. On the side toward the house there is a drinking fountain for the passer-by; the waste water drains from this into the side toward the street where there is a drinking-trough for horses. ‘In this way the problem of the waste from the drinking- fountain is solved. € A picturesque effect secured with ordinary stones set in concrete in a street fountain The oil is heated in the tank and forced out onto the road under pressure through specially prepared nozzles When the road-oiling season is over the tank and its fittings may be supplanted by another type of body Demountable Road-Oiling Tank Saves Truck’s Winter Time OT long ago it was considered the up- to-date and progressive thing to own a motor truck for each kind of special service for which such a truck could be employed. But now the most progressive idea is the truck which can be used in more ways than one, thus reducing the cost and increasing its efficiency. This is usually ac- complished by providing two or more bodies to be used interchangeably on one chassis. The- road-oiling tank and mechanism shown in the accompanying view is mounted on a separate sub-frame, so that it can be removed as a unit from the motor truck in less than half an hour. Ten hold- ing-down bolts are removed, and the entire apparatus is lifted off the chassis by an overhead crane. This overcomes the great drawback of mounting equipment of this kind on motor trucks.. When the road- oiling season is over the tank and its fittings may be removed and another type of body fitted in its place. Hence the truck be- comes a money-maker all the year round. Formerly it was a dead loss in winter be- cause the tank was fixed. The tank shown heats the oil and then forces it on the road under pressure through special nozzles. 190 Popular Science Monthly Protecting Flocks from Coyotes by Means of a Gas Lamp “Gun” gas lamp known as a “coyote” gun is being used extensively by western ranch- men to protect their flocks from the ravages of coy- otes. The device consists of three chambersanda lamp box. In the upper chamber is water which drips into the larger chamber below, filled with calcium carbide. The greater part of the gas feeds through a tube to the blaze but a quantity is forced into the third chamber, on the left side, and from there at about one minute intervals it feeds through to the lamp box and causes an explosion similar to a pistol shot. The device is attached to a spring and suspended four or five feet above the ground. The explosions keep the ‘“‘gun’”’ revolving and throwing the light in every direction. Coyotes are afraid of a light and flee at the sound of a gun. In the past it has been the custom of the sheepmen to keep herders on duty all night, firing a gun every few minutes, and keeping a big Coyotes are afraid of light and flee at the sound of a gun. This gas lamp causes an ex- plosion at regular intervals which is similar to a pistolshot. At the same time the lamp revolves constantly, shed- ding light in every direction NOVEL | campfire burning brightly. The “‘gun”’ does away with this. It will operate for a period of about fourteen hours without refilling. Shipping Day-Old Chicks Is Profitable at Both Ends HEN little chicks come need neither water nor food for sixty hours. That fact has given rise to a new busi- ness. Day-old chicks are sold and shipped by people who operate incubators. Those who buy are relieved of the trouble, of the incon- venience and to some extent of the uncertainty of hatch- ing. Only asmall percentage of day-old chicks perish while on the way from shipper to customer. People are thus enabled to get the little chicks and begin the poultry busi- ness without the necessity of purchasing an incubator. Special boxes of pasteboard, are made for shipping purposes. Some have a capacity of twenty-five chicks, some of fifty and some of one hundred. It is doubt- less best that no more than twenty-five shall in any case occupy a single compart- ment. The walls of the boxes are mod- erately thick, and some soft material as grass is put in the bottom. Otherwise there are no especial provisions against cold weather. However, the chicks themselves may be depended upon to cluster together and in this way keep one another warm. The boxes are not to be opened en route, nor are the chicks to be given food or water. Successful shipments have been made for two thousand miles. Special pasteboard boxes are used from the shell, they [peer ee eS! eee ee =" * ? PE a Se ee ee eve Oe Popular Science Monthly This River Is One of Nature’s “Find It If You Can”’ Puzzles “FXO him who in the love of Nature holds communion with her visible forms,” she often appears as a most incor- rigible tease. She loves to clothe herself in mystery and propound enigimas and puzzles. The Hidden River, in Kentucky, so called because its source is unknown and its outlet undiscoverable, is one of her imagination-exciters. It comes to light for a short distance only, runs turbidly along without ripples or tides over its pale blue waters and vanishes into a cave leading no one knows where. Digging War Trenches with a Powerful Tractor HE present war has been fought with such rapidity that in many instances troops have not had time to dig their trenches and barricade them- selves before the enemy made fresh attacks. The demand appeared long ago for a trench-digging tractor, but such a machine did not appear on the European LADDER which can be used battlefields until recently, with equal facility on a_side- when the tractor illustrated was put to hill or in the home has been invented by work in France. * B. B. Keith of Mansfield, Ohio. It has It digs a trench as it goes along, just as_two additional legs or props, one at each the common farm tractor plows furrows side. This prevents the ladder from slip- as it goes along. The earth thrown upon _ ping, and increases its strength. When one side serves as the breastworks. The the ladder is on a level surface both extra trench-digging tractor is built on a larger legs are used, but when it is used ona hill scale than any seen in thiscountry. Itissaid or on uneven ground only the leg on the to be doing excellent work for the French. down-hill side is necessary as the prop. The extra leg on the ladder prevents it from falling over or slipping, and keeps it steady A Ladder Which Can’t Slip or Fall Over \ The powerful tractor which digs trenches just as an ordinary farm tractor plows a furrow. The earth that is thrown up servesas breastworks. Itisin use by the French. Soldiers are operating the machinc The Road-Rail and Its New Truck How it will save our highways seseeaaemeenmnememrmen Eee _T4f {COND RALLY AY S¥g-¢¢y— CAPACITY, teans WEIGHT. s2n9 PATENTED. AUG 9.0: PORLINIS OP LIGA | epee © PER. tox % ing improved roads is due to heavy motor traffic. Motor trucks and motor omnibuses carrying loads of five to ten tons at speeds reaching fifteen to twenty miles per hour now run over roads improved at large expense, and cause great damage. State highway authorities all over the country recognize this as a most serious threat to the permanence of their highways. To meet the situation, in part at least, Mr. Charles Whiting Baker, a well-known New York engineer, has designed a trans- portation system which carries its load on a A LARGE part of the cost of maintain- smooth steel rail and which furnishes at the same time a permanent and durable auto- mobile highway at low cost. The roadway consists of smooth Portland cement concrete. In the center of the road- way there is embedded a single line of steel rail, the head of the rail flush with the sur- face of the road, so that it does not inter- fere at all with the use of the road by auto- mobiles or horse-drawn vehicles. The cars which-run on this rail have double-flanged wheels running on the rail and they are kept balanced over the rail by ordinary vehicle wheels which run on the concrete roadway on either side. The cars are built with a low floor, only a few inches above the road surface, and the weight of the car-and its load is thus A section of the economical roadway. It is of smooth Portland cement with a single rail em- bedded in the cénter and flush with the. road surface. About ninety per cent of the weight of heavy trucks is carried on this rail. brought down so low that the load on the balancing wheels to keep the car steady is very small. Not more than ten per cent of the car’s weight is carried on the balancing wheels, so that even if the car with its load weighed as much as fifteen tons, the weight carried by the balancing wheels would be no greater than that carried by the wheels of an ordinary light touring automobile. — To propel the car there is at one end a gasoline engine, about the size of that used on an ordinary touring car, direct connected to an electric generator. On the trucks of the car are electric motors, which, by: a sprocket-chain transmission, drive the ‘Car’ Suitable controllers. wheels on the rail. distribute the current generated on the car to the motors on the trucks. The whole equipment is, in fact, similar to (but of. smaller size than) that used on railway gasoline-electric cars, 3a large number of which are in successful operation in various sections of: the country. As the car is very light compared with an ordinary railway car and is designed for low speed operation, the power required to drive it is small. The cost of building this kind of a roadway may be varied within wide limits according to the character and volume of the traffic carried. A concrete road suffers practically no wear from the traffic of pneumatic-tired vehicles. What causes the wear is the grinding action of steel tires of heavy wagons. The monorail in the concrete roadway is designed to relieve the road of the burden of such trucks and thus lengthen the life of the highway and reduce the cost of its maintenance. THO Se ey we Ce a oe Don’t use gasoline near a machine é a ‘ie In a single year in the United States 1,040 persons were burned to death and 3,120 persons injured (a weekly average of 20 persons killed and 60 persons injured) on account of gaso- line fires. From the transportation of gasoline alone there recently resulted a yearly damage amounting to nearly $118,000. Nearly all such disasters and losses are due to carelessness “Don'ts” for Gasoline Users —— Dont wash the hands with gasoline Don’t smoke cigarettes while cleaning clothes with gasoline. : If you are cleaning silk with gasoline, don’t rub it hard. Violent rubbing of silk generates electric sparks that will set fire to the gasoline. Don’t clean automobile parts with gasoline in an open can. Two pieces of metal striking together will cause a spark. fs Don’t smoke cigarettes while filling your fuel-tank. Don’t use liquid-fuel lamps with glass oil- wells if you can get metal ones. Don’t use gasoline in a room where there is an open light or flame of any kind. Don’t pour out more gasoline than you intend to use. Don’t use gasoline in a room where there is a machine which may cause a’spark. Don’t spill gasoline. Don't use gasoline to wash your hands. Don’t use gasoline in a room where there is an open light Don’t use gasoline where there is machinery with belts. Electric sparks are produced by the belts. Don’t use gasoline in a room where there is machinery with shafting. Don’t use gasoline in a room where there are electric switches or fuses. Don’t use gasoline in artificial light if you can helpit. Butif you must, see that the lights are electric and that the bulbs are provided with guards to prevent them from being smashed. Don’t use gasoline in an open pan without acover. Keep the cover handy and cover the pan when you are not actually using it. Don’t fill the tank of your liquid-fuel stove full. Don’t use a leaky liquid-fuel stove. Don’t fill a gasoline stove in a room unless the windows are open. You need plenty of air to carry the vapor out of the room. Don’t rub silk hard when you are clean- ing it with gasoline Don’t smoke cigar- ettes while cleaning clothes with gasoline 1902 194 A Fountain Brush Which Cleans Both Sides of the Teeth NEW toothbrush which can clean both sides of the teeth at the A same time—and wash them while » cleaning them—has been in- vented by Lincoln C. Stock- ton, of Denver, Colorado. The handle of the tooth- brush is hollow and is connected with a bulb filled with water or any cleansing liquid ’ from which the liquid may be discharged in- to the hollow handle and into the head of the brush, which is | provided with ducts Se IN oar to carry the liquid to the brushes. The brush is operat- ed in the same man- ner as the ordinary toothbrush: Thereare, of course; two brushes —one to clean the outside of the teeth and the other to clean the inside of the teeth. As the brush is moved back and forth the bulb is pressed from time to time, forcing the water or cleansing liquid to the teeth. VALVE SPRING. A Spinal-Column Harness for the Back-Bending Workman HE man who invents a substi- tute for the spinal-column, or some sort of contrivance to take the pain out of back bending, will make enough money to buy his wife a car- load of diamond tiaras. Evidently Robert E. Kelly, of Cocoanut Grove, Florida, had the diamond tiaras in sight when he invented his spinal-column harness illustrated on this page. Its purpose is to prevent fatigue of the back muscles—so he says. But does it? Hasn’t he overlooked the fact that the wearer must perform work in storing up energy in the spring and that he must constantly fight the spring’s tendency to bring him into an upright -position? he isn’t ! tain amount of extra work in storing up energy in the spring You squeeze the bulb, move the brush and clean both sides of the teeth at once FOUNTAIN SYRINGE Popular Science Monthly The invention consists of an elongated bar which, between its ends, is twisted into a coiled spring on which there is mounted a pad to rest against the body. At each end of the rod are padded grip-members. One of the ends is shaped to straddle the neck end of the body and to extend over the shoulders; the other end is shaped to pass about the legs of the operator, exterior to the thigh portions. members the brace is able to remain in position on the body of the operator, even when he is standing upright. When the workman assumes a_ stooping position the weight of the body is in a large measure sustained by the elastic tendency of the brace to assume the straightened-out position. Perhaps the inven- tor’s idea may be to he has been bending for some time. We ‘However, “The proof of the pudding is in the eating,” and the only way to find out - the good qualities of Mr. Kelly’s back brace is to try it out. ‘SHOULDER GRIPS Every time he bends over he has to perform a cer- With the aid of its grip- help the workman to... raise up again after | __can imagine that he. might find some difficuity along that line. ~ SS ae ee a a Popular Science Monthly Mr. Average Healthy Man’s Enormous Appetite N average man who has seen seventy- five years of life has eaten an amount of food equal to some fifteen hundred times his own weight. One hundred and ten tons of food he has consumed, of which the bread alone, if it could be piled separately, would occupy a space equal to that of a good-sized building. The vegetables on reappearing would fill a train three miles in length and the bacon when placed end to end in single slices would stretch along a line four miles long. The reappearance of five tons of fish and one-fifth of a ton of cheese would surely haunt him, while twelve thousand eggs, ten thousand pounds of sugar and fifteen hundred pounds of salt would put in their claim. And he has smoked no less than 250,000 cigarettes. Let’s hope he has saved the coupons. The Sandwich Man As an Ally of the Telephone Companies EN a disastrous fire swept through Paris, Texas, not long ago, utterly destroying more than fourteen hundred homes and many business houses of the city, the telephone system was badly crippled. Not only were private lines destroyed, but on account of the scat- tering of families into temporary quar- ters all over the city it was almost im- possible to locate any one called over the long distance wires. An ex- change was connected tem- porarily to handle such calls, but the problem was to find the person wanted. It was finally solved by employing the sandwich-man idea. Several boys were en- 3 i gaged to carry blackboards eTR sandwich fashion, on which were written in large letters the names of the persons wanted. Primitive as was the plan (dating back to PIN Pots LG, 2 Se i ; ee ore eee Ca & ve - 1780, to the fourth Earl of as Sandwich, who originated 5S the idea) it cleared up the : situation until the tele- — phone lines were restored. © ~~ The sandwich boys were not of the usual silent type but whistled and called to every passerby to read the sign. ‘ : WANTED > ange! _ Long Distance if you see him stell.fim . es Lt ~ The expedient to which the telephone companies of Paris, Texas, were forced to resort — The detachable motor drives the bi- cycle at a speed of thirty miles an hour r Convert Your Bicycle into a Motor- cycle with This Detachable Motor NEW bicycle motor, so small that it reaches only from the top of the front wheel to the handlebars, is to be placed on the market for those who wish to convert their bicycles into motor- cycles. The motor, a com- plete gasoline engine in minia- ture, has a flywheel and a muffler. It is clamped to the wheel by a strong side-fork, so that a steel traction-pulley presses down upon the tire at its center. The gasoline-tank on one side is balanced by the weight of the flywheel on the other, so that the pulley-groove is pressed down uniformly across the tire. The ignition system consists of a small spark-coil and two dry cells, which are stored in a small case suspended from the horizontal bar of the bicycle frame. 196 Popular Science Monthly favored blue-black variety and is guaranteed by Nature not to fade. To be sure, it is rather a long way off, being located in Algeria, but that is not much of a considera- tion. The ink river is formed by the union of two streams, the water fromone of which is impregnated with gallic acid and the other with iron. These are the two necessary elements of the best ink. . y The earliest ink of the man- i made variety was prepared t by suspending a bag of soot k, : v4 or other carbonaceous ma- The car-puller is located beside the track and is belted terial in some sticky solution to a motor or to a line-shaft through a clutch-pulley | such as glue or varnish. Later the cuttlefish was found Car-Pullers Take the Place of to yield a secretion which could be used for Switch Engines the purpose. But the modern blue-black HIFTING railroad freight cars at in- ink is obtained from gallic acid, usually dustrial plants by hand labor is both from China or Turkey galls, mixed with expensive and slow. With a switch engine iron sulphate. This is the kind with which it is still more expensive.’ These are two the Algerians might flood the market. reasons why car-pullers are coming more and more into use. The car-puller consists ; ‘ | of an electric motor which ease a cable Mahogany Cigarette Mills That Pass _ drum, winch-head or capstan around which | the Cigarettes a rope or steel cable attached to one freight STRIKING and convenient accessory car or a string of cars is fastened. When for the smoking room is a cigarette the drum revolves the rope tightens and the © mill. One type is turned by the hand as cars are slowly pulled toward the machine. shown in the illustration; at each revolu- In one plant a twenty horsepower motor tion it turns out a cigarette from the was strong enough to handle ten loaded ‘‘hopper.’”’ In the stork type the user freight cars on a slight down grade and to pushes the button; this causes a panel to shift from six to ten loaded cars daily. open, and the stork puts his The maximum length of haul is about head. down into the in- three hundred feet. The car-puller terior, takes out a cig- shown in the accompanying illustra- arette and hands it tion is capable of hauling from three to five loaded cars. It is small and very compact. Is Ink Becoming Scarce? Not in Algeria ITH the price of ink soaring to keep pace with paper, and the cuttle-fish seemingly on strike, the manufacturers of writing fluids will probably be glad to have their attention called to a river of the purest kind of ink waiting to fill the demand from a seemingly inex- To get a cigarette you turn the mill at the left haustible source. It is of the or press the button at the side of the stork to you politely. 1 ae ee ee Raabe il at ~ fest ee ee Oe ee ET ge ee Ce ee ei ee ee | eee ree Popular Science Monthly Next Summer’s Ice. They are Cutting It Now with Electricity NLY six years ago this winter ice was cut by driving a horse over a slippery} field. The horse dragged a sharp-edged -ice-plow which dug deeply into the ice and finally cut it into pieces as small as was possible by such a method. How differently is this done now. A single electrically-driven, rapidly rotat- ing blade like a buzz-saw drives itself across the field, cutting it into large oblong pieces as it is guided and pushed by the man behind. After this, the pieces are floated into a large saw-mill where they are rapidly cut into small cakes. The mill contains two separate bat- teries of saws, all electrically driven. The first battery consists of three saws at the front of the mill which are evenly spaced apart. Some distance behind, the second battery, consisting of seven saws, is placed. As the floats of ice reach the mill they are pushed against the first battery of saws and pulled along by them as they are cut into four pieces. Next, the strips are turned around through an angle of ninety degrees and fed into the second battery. Here they receive their final cut and come out as cakes, generally square or oblong in shape. These cakes are then floated downstream to the warehouse where they are stored until delivery. Floatsof ice forty feet wide by fifty-five feet long can be cut in a minute into small pieces. 197 The toothbrush fits snugly in a hollow chamber in the back of the comb from which it can not easily slip out A Combination Comb and Tooth- brush Holder ERHAPS the most novel combination in this day of two-in-one devices is the one illustrated in the accompanying photograph. It is a small comb, of vest- pocket size, with a hollow chamber in the back, into which a toothbrush may be slipped for safe keeping.. The upper and lower walls of the hollow chamber are thickened at one end to provide a restricted neck and flared mouth, to conform to the contour of the brush-handle. France Completes the World’s Largest Tunnel FEW months ago, France counterparted her re- markable engineering feats along the breastworks of Ver- dun with an equally great achievement through the peaceful hills of Rove. A tun- nel seventy-two feet wide, fifty-two feet high and four and one-half miles long—larger than any other in the world— was completed. This spacious tunnel, the result of twelve years’ planning and labor, is part of a great canal system which will, in the near future, connect the network of the canals of France with the The mill through which the ice is floated to be cut into cakes before passing downstream to the warehouse for storage Mediterranean Sea. The sys- tem will be fifty one miles long. 198 The weight of the bag tightens the fit of the strap around the wrist so that the bag cannot slip off It Is Almost Impossible for You to Lose This Hand-Bag . NEW YORK man has invented a sim- ple device which should be a boon to careless women, as it prevents, the loss of the hand-bag. The leather handle is fitted with two metal slides on one end of which is a roller. These slides are fitted to the handle straps and are connected by a short piece of leather of the same width as the handle. When the handle is slipped over the arm, the metal slides are pulled up by the weight of the bag “so that the handle fits close around the wrist and. makes | it impossible for the handle to slide over the hand. This is only one of many devices which have been invented and placed on the market recently for the purpose of helping women to hold on to their purses, which are so easily lost in crowds. The average man is doubtless more inter- ested in probable means Of persuading them (at least those of his own immediate family) to keep possession of the contents of the purses a little longer. The first bullet which was fired rammed in the barrel, effectually blocking the path of the second bullet Popular Science Monthly Consider the Cow. She Helps Make Buttons and Shoe Polish ITH no apparent effort the cow goes through her span of years yielding her full quota of milk and look- ing always as if she could impart great secrets to the world if she had the gift of speech. She is an industrial asset, not a mere purveyor of baby food. It has been proven that casein, which forms over three per cent of the total weight of cow’s milk, is an important commercial product and may be profitably employed in the manufacture of glue, combs, but- tons, linoleum, hair-pins, toys, paints and even shoe polish. In the preparation of casein for com- mercial purposes, about seven hundred gallons of skimmed milk are put into a great vat and heated to about one hun- dred and thirty-five degrees, Fahrenheit. Then very dilute sulphuric acid is added to precipitate. the casein or curd. The whey is drawn off and the curd is drained and cut into chunks, after which streams of cold water are played on it to wash out the acid. The curd is then dried with rotary fans and ground into powder, in which form it is placed on the market. One hundred pounds of skimmed milk will yield about three and _ one-half pounds of casein powder. Saved by the Bullet Intended to Kill Him T is better to be born lucky than rich, . they say, and no doubt a certain policeman of Alton, Ill., will sanction the sentiment. He was one of a squad sent recently to arrest two desperate criminals who had been located hid- ing in a boarding house. When cor- nered, one of the men at bay press- ed the muzzle of his revolver against the policeman’s abdomen and pulled the trigger twice in rapid succession. . The first bullet rammed in the barrel about an inch from the cylinder. This effectively barred the pathway of the second shot, the force of which tore a strip from the barrel an inch long through which the bullet escaped, thus destroying the usefulness of the weapon. ee ee ee ee ee ee oe eee Keeping Track of Piece Work An automatic timekeeper calculates the time each workman spends on a job, and needs no verifying N ingenious machine has been in- vented which automatically calcu- lates the time spent by any workman on any job. The machine prints this time on a card in addition to the times of starting and stopping. Each workman uses a card for each job. He stamps it at the machine when he to determine the payroll efficiency records and data for piece work prices. The machine itself consists of a small cylindrical barrel about eight inches in diameter and six inches high. It has a clock on its upper face with two handles, one on either side. These are used for printing the various times on the cards. starts and again when he finishes. Each In operation, the card is first inserted in card shows the a slot on top of starting and stop- verr. enrwoves ar mites the machine and ping time of each eS the right-hand be ORDLA NO. OPERATION NO VANTITY ~ — - job and the 5%. €2| “720 63 | 500 a _ x»| lever is pushed elapsed time = f i= 0 : ee ee away from the Ps ° = * 2 DeSCRirtion ‘Jeet 3 spent on it. |.*><¢* 8} es ae operator. This au = > -* re Hence the cards |< - Sate prints the date can be used in bo es = & and the time of determining |e > oo day, a printed many vital |« ” . E18 arrow indicating factors in the cost ERS EN hese Oe, waged om Oy the minutes anda 7 os . of modern factory dete Se a eB 3 wedge the hours production in- | ‘A 2a7, VA as shown on one cluding the labor | = nats) oe arn ©. =| Of the cards re- cost of the prod- Far? ae produced on this uct; the produc- tive and non-pro- ductive hours; the machine time, and the time actually —% spent on the job, G & > A sample card. It shows that workman No. 75 worked 3.2 hours in the morning and 2.7 hours in the afternoon on Order No. 92, on operation 63 page. Then by pulling the right lever toward the operator before the card is removed, two dials which form a part of the record are printed. One indi- cates hours, the other tenths of hours. The calculagraph, showing the two levers by means of which the cards are printed. At right of the picture it is shown in use in a factory where each job foreman reports by telephone to the timekeeper in the central office the record of each job 1090 You don’t need to scratch your phonograph records when starting them, for the flashlight shows you the exact position of the needle A Flashlight To Show the Position of Talking-Machine Needles OMETHING new in the line of attach- ments for talking machines has been placed on the market by George E. Ber- necker, a well-known Milwaukee electrical designer and inventor, who has developed a flashlight illuminating device, makes it easy and safe to operate talking machines in the most subdued light. The illustration above shows the flash- light attached to the machine: The light is flashed directly upon the path of the needle so that there is no danger of the record being scratched when the machine is started. New Type Motorcycle Uses Two-Cycle Motor with Magneto in Flywheel OOK at the accompanying picture of a new motorcycle. Notice that it is not driven by gears and that it is very simple. ARMATURE_ COILS PERMANENT MAGNETS CIRCUIT BREAKER CAM. CIRCUIT BREAKER CONNECTION TO SPARK PLUG7 which- Popular Science Monthly Since a two-cycle instead of a four-cycle motor is used, as well as a flywheel mag- neto, the usual valves, gears and cams are dispensed with. The employment of the flywheel magneto elimi- gears and sprockets so that the only drive taken off the main belt drive to the rear wheel. The flywheel magneto is a new departure in motorcycle construction. It is cup- shaped and has a heavy rim, to the inside of which are at- tached a pair of permanent magnets as shown in one of the accompanying illustrations. The arma- ture coils, the circuit breaker and the con- denser are mounted ona circular plate which is carried on a boss on the crankcase of the motor and which fits snugly into the cup- shaped portion of the flywheel, without, how- ever, contacting with the inside of the rim. At every complete revolution of the fly- wheel the field magnets are brought into proper relation with the armature to induce the igniting current. Atjust the proper in- stant a cam mounted on the flywheel hub operates the circuit-breaker, causing the spark to jump the plug gap. The timing of the ignition is effected by loosening the clamps holding the stationary plate to the crankcase boss~ and rotating the plate slightly in the proper di- rection. The advantage of such an arrangement is that there are fewer parts ‘to be greased and cared for or to get out of order. The flywheel magzeto is cup-shaped and has a heavy rim to which is attached a pair of per- manent magnets. There are none of the usual valves, gears and cams in this machine nates a series of driving crank-shaft is that of the a lat (i ath al El ala al eo mes aay Popular Science Monthly Did the French Borrow this Idea from the Ancient Druids? HERE are a number of trees in France which harbor picturesque little chapels. One of the most unusual is the oak of Allouville, a Norman village in the depart- ment of Seine Inférieure, in which the oak stands ona level piece of ground some distance from the church. Its trunk, which is now almost com- pletely hollow, has a cir- cumference at about three and a half feet above the soil of more than thirty feet, and its top- most branches are nearly six- ty feet from the ground. This oak con- tains two al- tars, one above the other; the lower one is dedicated to Our Lady of Peace and was constructed towards the end of the seventeenth century by a former priest of the parish, the Abbé du Dé- troit. The chapel above the one to Our Lady of Peace is of much later date and is OPA adie” aS called the = Chapel of the Cross. The yew tree of La Haye-de-Routout, in the Department of Eure, is of an equally venerable age. The circumference of the trunk is about twenty-nine feet and its greatest height is fifty-seven feet. The little altar with a cross above the pedi- ment is placed within the hollow trunk of the famous tree and the interior of the chapel is reached by ascending a step. On certain days a priest comes to celebrate mass at the altar, which is decorated with a group in carved wood representing Saint Anne ‘of the Yews” and the Virgin. Other districts of France also contain tree chapels. An altar in a giant oak in Allouville, a village of Normandy. The tree is nearly sixty feet tall and about thirty feet around 201 Why Are Abandoned Flour Mills Not Utilized as Lighting Stations? HY are abandoned flour mills not used for lighting stations? Water- power is to be had freely and abundantly, since the flour mill is nearly always the nucleus around which the oldest of our rural settlements have been built. The question suggested itself to the editor of this magazine who, in turn, asked one of the largest electric manufac- turing companies in the country to give an answer. After an inquiry among engineers in this plant and letters from more than six hundred mill- ing establish- ments all over the country, it was proved that no abandoned flour mills had ever been transformed into lighting stations. On the other hand the can- vass brought forth the in- formation that many milling firms furnish electric light and power in addition to the regular products. In this con- nection it is interesting to note the various reasons given by mill owners for not using electric power in lieu of waterpower. Replies gathered from an extensive circular letter campaign show conclusively that the average miller would like to avail himself of the electric drive, but the economy of waterpower, the real or imaginary high cost of electricity, or the sacrifice of an expensive steam plant holds him back. Out of six hundred and fifty-eight replies only ten wrote that they did not see the need for electric drive or were not in- terested in statistics concerning it. el Fs 202 ‘Popular Science Monthly Drying the Family Wash- ing around the Stove The cage is placed around the stove but far enough away to prevent scorching the articles draped uponittodry. Theclothes dry quickly HEN the weather prophet or the almanac predicts storms or bad weather, the up-to-date housewife does not postpone her washing. Neither does she order the clothesline strung up in the kitchen where it is an eyesore and in every- body’s way, nor outdoors where the clothes might flop dejectedly for days in the rain. Instead she sets up—if she is fortunate enough to have one—the clothes-drying apparatus which Benjamin Gallsworthy, of Port Arthur, Texas, recently invent- ed. This is in the form of a latticed frame joined together in sections, upon which the clothes are hung. The ends of the vertical rods of the frame con- verge at the top forming a kind of cage. This cage is placed around a stove. The heat from the stove dries the clothes quickly and makes it possible for the laun- dress or housewife to finish up the work regardless of the weather. The sections of the cage are disconnected simply by removing the pins which join them, so that it is an easy A Machine Which Takes the Backache Out of Carpet-Beating Ho would you like to beat your carpets with the same ease with which you push the lawn-mower over your grass or the baby carriage on the sidewalk? You can do it. You don’t need to bend over until your back seems to be breaking in two, and your carpet will be cleaned just as, thoroughly as if you pounded it with beaters in your own hands. All this is possible with a new carpet- beater devised by Edward Smith, of Newark, New Jersey. Its operation resem- bles that of the lawn-mower. You run it back and forth over the carpet, which motion actuates a number of paddles that strike the carpet. The paddles are operated by teeth on a drum or cylinder which moves with the wheels of the apparatus. The paddles extend in front of the machine and their upward movement is .opposed by springs, these springs producing the beating movement. As the machine is moved forward the drum revolves, and its teeth come in contact with the paddles, lifting them up about four inches above . the carpet when the springs force them to descend. This is the beating motion. The faster the machine is moved the faster the paddles hit the carpet. matter to set it up or take it down. It can be easily stored away until needed. Running the device over the carpet operates a number of paddles connected with the wheels. ‘The faster the machine is moved the faster and harder the paddles beat the carpet . bs 4 ; a feet ot hall Alice M. Seabrooke, Superintendent of the Popular Science Monthly 203 More Things Are Made from Yeast Than Good Cooks Dream Of ECAUSE it is so essential in the mak- ing of bread and beer most of us think that yeast is useful for nothing else. But the Berlin Institute of Fermentative Industries calls attention to the fact that valuable flavoring extracts and _ tonics can be obtained from it and a relatively large percentage of muscle-building matter. _ Its remaining constituent, a mass of cellu- lose, can be used to make a very hard mass, known as ernolith, an excellent non- inflammable substitute for celluloid. A Baby-Incubator Made Out Of an Old Soap-Box NOTHER use has been found for the time-honored Soap-box, though why all boxesofacertain sizeand shape should be called soap-boxes Science itself has not as yet been able to decide. At any rate Dr. Woman’s Hospital at Philadelphia, Pa., has invented an incubator which can be made from a box of the conventional soap-box type. The model, shown in the illustra- : ; tion, was exhibited at the annual conven- The tomato-potato plant, with tubers under- tion of the American Hospital Association. ground and perfect tomatoes above. The The incubator contains all the plant bore abundant crops of both products features of the expensive types, with arrangements for heating and moistening the air and ~ for keeping the temperature undercontrol. It is pro- vided with a glass top with two sections. There are well-protected openings on all sides so that the little patient can be watched and attended without being disturbed. Growing Potatoes on the Roots of a Tomato Plant ONSIDERABLE interest has been aroused by the grafting of a tomato plant on a potato plant at the Pennsyl- vania State College. -Al- though the idea is not a new one, it demonstrates clearly the ease with which these two closely-related plants may be grafted. Only one attempt was made in the grafting. The common in- verted “saddle graft’’ was used. The plant was wrapped with raffia at the junction of the two pieces and it was placed in a humid atmosphere for several days until the union was perfected. Later the plant was shifted to the outside, where little attention was given it. ‘Tubers finally developed on the potato part and tomatoes on the top. According to the authorities them- selves, the demonstration is of inter- est only from the standpoint of its being somewhat unusual. It is of The box incubator which was constructed at a cost of five dollars. Above is a photograph of Dr. Alice : M. Seabrooke, of Philadelphia, who invented it doubtful economic value. 204 The watch in the center is the largest in the world. At the left below is an ordinary-sized watch and on the right the smallest ever made The Largest and the Smallest Watches in the World HE ordinary watch is a simple, com- fortable time-piece to be dropped negligently into a convenient pocket and to be referred to casually and. without incon- venience. But all watches are not thus easily handled. The largest watch in the world, for instance, could hardly be carried conveniently at the end of a fob, since it weighs one hundred and fifteen pounds, while the smallest watch in the United States could be easily lost.in a vest-pocket of change, since it is scarcely larger in circumference than a dime. Aside from their unusual sizes, these big and little watches differ in no respect from their broth- ers of normal development. They keep excellent time and perform in all respects as an orderly, well balanced time- piece might be expected to do. The watches, contrasted here, were built originally for advertising purposes. The smallest watch has a diameter of only seven-tenths of an inch, and a circumference of two and one-fifth inches. Popular Science Monthly Its weight is .113 ounce Troy. The big brother of the smallest watch weighs one hundred and fifteen pounds; it has‘a diame- ter of seventeen inches and a circumference of fifty-three and two-fifths inches. Both watches are stem-winders, though to wind the smallest one it is necessary to use a pair of little tweezers. The larger watch has_ twenty-three jewels. It cost more than ten thousand dollars. Directing Newport’s Traffic from a Portable Platform RAFFIC Policeman Freeborn Cogge- shell, of Newport, R. I., has solved the traffic stand problem all by himself. He has constructed a platform which meets the peculiar conditions of the difficult post he halds, which is situated in a five-cornered plaza to which traffic converges at an average of twelve hundred vehicles of all descriptions an hour. Two streets have a grade of about thirty- five degrees, and all are narrow and dan- gerous. Only at one point may a police- man stand in order to have a clear view to regulate traffic, and there it is that Police- man Coggeshell and his platform’ are located. Since Cogge- shell has been directing ‘traffic 5 in the square he has stopped one hundred and. three runaways. That is the main reason he has equipped his platform with a mirror to show him what takes. place behind him. In the mirror he ob- tains a view of the square and Se The policeman wheels his platform to the point at which all five streets cross, and with the aid of a mirror watches the traffic in every direction snow. several streets. The umbrella insures a most welcome protec- tion from the sun, rain, and In stormy weather a burlap apron is fastened around the stand to protect the officer. When the day’s work is done Coggeshell wheels his platform to a nearby store. a ee a) 1 6 7 r q er ss ld ever ee Eliminating the Waiter in the Restaurant : DETROIT man, John F. Daschner, has a plan for eliminating the restau- rant waiter and putting in his place some- thing which doesn’t talk, or hold out its two hands for tips, or spill the soup. His invention is a dumb waiter in more than one sense. The system is said to embody the luxuries of a select dining- room equipped with conveniently ar- ranged tables and comfortable seating facilities wherein pa- trons may dine with ease and privacy, receiving prompt, efficient and sani- tary service at rea- sonable prices. While the system ‘eliminates the wait- er in the dining room it utilizes him as a serving department attendant, where his duties are less ardu- ous and where he ‘s-- not subjected to the whims and caprices of critical patrons. No money is wasted on waiters’ uniforms or dress suits, nor is there any scurrying of waiters. The table at which you sit is the top of an elevator shaft leading to the kitch- en below. The ele- vator is operated by a cable passing over a series of pulleys to a motor-driven drum. Simply by manipulating a pushbutton in the table top the eleva- tor descends to the kitchen, where it is Popular Science Monthly exie 5 Check off on the menu card the dishes you want, press a button in the table-top and the dumb-waiter descends from the center of the table to the kitchen below, where the order is filled and then sent up by the same route 205 We Don’t Eat This Fish Because It Is Unfashionable T seems as if there are fashions in fish just as there are in wearing-apparel. A fish that brings in German markets nearly four times as much per pound as our fresh mackerel, and con- siderably more than haddock, is thrown away by our fisher- men because no one wants toeatit. And it is mighty good fish, too. Those who eat it praise it for its delicate flavor. Even the Englishlike it. Every year they consume three thou- sand tons of it. Yet we will have none of it. This fish is known as the goose-fish, angler-fish, devil- fish and monk-fish. True, its appearance is against it, but still the epicures in England and Ger- many demand it be- cause it is delicious. Analyses made by the Bureau of Fish- eries on samples show that goose-fish contains’ consider- ably more protein than flounder, slight- ly more than a cod, a little less than halibut, and consid- erably less than sir- loin steak. The goose-fish has an average length of three feet and is broad and flat, some- what resembling the flounder in general outline. The only way to get it, says a Philadelphia wo- man, is for the housewives to club together and demand loaded and sent up again. A tripping it. At the present time fishermen do not finger automatically arrests the elevator at the top or bottom of the shaft. take the trouble to bring it home, but dis- card it from their nets. 206 Popular Science Monthly A rectangular box containing a bed of char- coal and a screen is fitted to the roof leaders Filtering Rainwater from the Leaders Through Charcoal ESIGNED to be fitted to the roof leaders of a country house to filter all the rain water flowing into the cistern, the simple filter shown in the illustration above consists of a rectangular box with a bed of charcoal and with a removable cylinder at the top. One half of the cylinder is a screen and the other half is of solid galvanized iron. When the screen half is at the bottom, the water flows through it and thence down through the charcoal bed into the pipe leading to the cistern. The strainer catches the large refuse, such as leaves, and the charcoal removes the finer parti- cles of objectionable mat- ter. When the cylinder screen is at the top the water collects in the solid half until it over- flows and passes out through a waste pipe to the ground. Yj A removable lid is ~~ # provided so that ,*/§ the leaves and other refuse which collectin thestrain- er may be easily l removed without inconvenience. The tank supplying the gas for the headlights will furnish fuel for the cooking, when a hot plate is used Taking Care of Honey Bees During the Winter EES, asa rule, take care of themselves. It is their ability to do so which makes. them valuable to man; for the honey they provide is not intended for any other use than their own. But in order to help them keep in such good condition that they will produce honey enough for themselvesand an. abundance to spare, it has been found ad- visable to keep them warm in winter by insulating their hives thoroughly, top, bot- tom and on all sides. According to the Chief of the Bureau of Entomology, the choice of insulating ma- terials is of minor importance. The ma- terials commonly used—shavings, sawdust, leaves and chaff—do not differ greatly in insulating value. tection afforded which is the chief considera- tion. Bee-keepers have claimed that over- insulation is detrimental; but the Chief of the Bureau insists that exhaustive tests have proved that it is scarcely possible to provide too much protection for the bees during the winter months and the spring. A Hot Plate Camp Stove for the Automobile Tourist HY build a fire to cook your meals while you are touring the country, when the tank supplying the gas for your headlights will perform the trick for you? The only equipment necessary, aside from the tank and a match, is a hot plate stove, weighing but six pounds, and small enough to be packed away under the seat. When the gasoline is turned on full the stove con- sumes about three and one-half feet of gas an hour giving a flame suffi- — ciently intense to boil a quart of water in three minutes. The stove consists of several burners and a plate $ a PRR. food to be cooked is placed. All that is necessary to pre- pare the stove for use is to slip the rubber tubing on the hot plate. The plate can be used in the same way as the small electric stove. It is the amount of pro- upon which the a ll i ae eee | en ese ee a ee Te 7 , ey en |. ee ee | Popular Science Monthly 207 Afraid of Fire? Then Carry a Pocket Fire-Escape HE traveling man comes in for full consideration from the inventors and experimenters of the day. Whether it is because he is so ubiquitous, or because he is such a necessary evil, something new is constantly being placed on the market for his convenience or to protect him from danger. This time it is a pocket fire-escape. With it he can get out of a burning hotel or other building before the swiftest fireman can get a chance to make a noble and spectacular rescue. All that he has to do is to open his suitcase, take out the little aluminum box that looks like a soap-box, open it and attach the end of the coiled steel wire cable to any available hook or loop it around the bed-post or other piece of heavy fur- niture, fasten around his body the strap and “‘seat”’ arrange- ment which is part of the device, and then hop out of the window. The casing containing the steel cable is provided with an indicator on which is clearly marked the weights which the cable will sustain. This indicator is connected with a control which adjusts the mechanism in such a way that the rate of descertt is governed by the weight sustained. For instance if a man weighs two hundred pounds, he turns the indicator until it points to that number and his drop is no faster than it would be if he weighed only one hundred pounds and turned the indi- cator to one hundred. In this way the shock of a sudden drop is avoided, although you can go down twenty stories in one minute. The limit of the carrying capacity of a one hundred and fifteen-foot cable is two hundred pounds, but another size is manu- factured which will sustain four hundred pounds. You can go down over the porch or from a steep roof, and if you should become un- conscious from fright you are still safe. Besides being of value to the traveler, it would seem to be a convenience to firemen, also. Even children can use it. The device consists of a coiled steel wire cable and a strap and seat arrangement. The rate of descent is governed by the weight of the person How a Whale Fought a Submarine and Sank Her THE vessel “W. S.” was recently sunk by a submarine without warning and within sight of the coast-line of Florida. The vessel was damaged so badly that it sank within ten minutes, its crew barely escaping with their lives. A monster whale on coming to the surface, came up against the sharp keel of the vessel, and it must have received a disagreeable cut, for it im- mediately attacked the boat and with one whack of its tail stove a large hole in the vessel’s bottom. The water filled the boat to its deck in less than ten minutes and it went to the bottom almost immediately. . While this matter cannot be directly traced to any warring nation, it is possible that the whale learned its bad habits from the manner in which other neutral vessels have been sunk in the last few years. 208 Popular Science Monthly - OPENING LATCH QUADRANT \ GEAR > DOTTED LINES INDICATE LEVEL POSITION OF DEVICE A pivoted platform is constructed flush with the roadway in front of the bin in which the truck is to be unloaded. By turning a crank five tons can be dumped in a minute To Unload This Truck You Simply Tilt the Platform WESTERN milling company has found it profitable to use motor trucks which can be tilted in their entirety. The plan pays because the longest truck run is not more than eight hundred feet. All motor vehicles of any kind turned out to be failures because they lost too much time being loaded and unloaded. Study the accompanying illustration and you will see that the tilting device consists of a pivoted platform flush with the road- way in front of the bin in which the load of the motor truck is deposited after it has been carried from another part of the plant. The fulcrum of the platform coincides with the vertical line through the center of gravity of the truck with its entire load. This makes it extremely easy for one man to tip the entire vehicle, simply by turning a crank-handle at the side of the truck. The crankhandle is connected by means of chains and gears with a large toothed gear sector bolted to the under side of the plat- form. After the grain has been dumped, the platform and the truck swing back to the level position by a half turn of the crank- handle, simply because the truck is heavier in the front than in the rear when empty. How Much Do You See When You Look at an Object? HE various committees and individuals interested in the ‘‘safety first’? move- ment are agreed that although the move- ment is still in a progressively fluid state there is not much more that can be done until the individuals most concerned are taught to use their eyes more effectively. “Having eyes they see not,” is the plaint of those who would safeguard the general public from the hundred and one accidents that daily occur. It might prove pleasurable to compare notes on observation. Let two people, for instance, take the same walk or view the same object for the same length of time and then tell about. It will be found that hardly one out of ten will notice more It was the than the most obvious facts. It custom of one of the old philosophers to give a new student some simple object— in one case it was the head of a fish—and tell him to study it and then tell all he knew about it. The student usually re- turned in about an hour’s time with a com- pleted paper on the subject; but the paper was generally returned with the remark that if it took an hour to learn such a little it would require a month perhaps to get a fairly good grasp of the subject. emer Pee eee er a ‘with her samples of Popular Science Monthly - 209 All papier-mAché heads look alike eee = when they come to Miss Stevens. When they leave her they are distinctive enough to be named Here they are, just as fresh as if they stepped out of Madame’s shop in Paris. The third one from M the right is not sleepy but demure Is This the Secret of Some Vaudeville _ Ventriloquy? ITTLE wooden Johnny is an actor who is frequently seen on the vaudeville stage. Haven't you often won- dered how well he speaks? Hesitscontentedly on the lap look hanging from hooks and of his sponser, and without supported stiffly by iron rods. = : the least trace of bashfulness, Now picture to yourself how much - or hesitation he tells the audience prettier they would look if there were whatever they want to know. human heads in that window to wear - Let us look into the them, tilted at the proper angle. TRANSMITTER secret of the talking dum- Of course shop owners have geceiver Py my. Ventriloquism is one known of this problem ‘ explanation; but a simpler for years, but they ~ Jess ‘ecm one is to be found ina never thoughtseriously DUMMY AND ASSEWGcr patent which has re- of solving it—not until cently been granted to Frances Simpson Charles M. Price, of Stevens came along Boston. From the ventriloquists’ point of view, Mr. Price’s idea is distinctly an improve- ment on the “regular” way. A telephone receiver is secured in the hollow head of the dummy. Connected with it are ordinary telephone wires which lead to a transmitter under Hats Are Made for Per- sonalities—Not for Heads FTER all, hats are made for personal- ities. If you want to be convinced look at a col- lection of bonnets in a smart shop window. No- tice how lonesome they papier-maché heads and showed them just how different a hat looks when it tops a coy and demure, or a chic and mischievous face. The shop owners who took time to listen to her are glad they did now. For papier-maché heads are all the the stage and rage. io | = speaking through Miss Steven$ is . ysigtanr a this is a man. an American girl Be ge oe Placed in thedum- who has studied art in my’s stomach isa Italy and France. telephone transmit- The heads which she ier, which is connected makes are of as many with receivers on the different kinds as there When little wooden Johnny is spoken to, 25sistant s head, so that are different types of she “ventriloquist’s” assistant has no he knows just when and personalities. trouble at all in hearing and answering What to answer. + Housekeeping XS Above: -A new device for wax- ing flatirons consists of a round honey- comb board about five inches in: di- ameter, which is saturated in beeswax Above: .A table top made in cight sections, which will fit any table, round or square, and enlarge it for special occasions. The sections are plush-lined so as not to scratch the wood A sliding door for the pantry is a convenience where a swinging door would be impossible or very much in the way. When closed it looks like a panel of the wall Made Easy n A lighter which is. composed of a roll of one hundred caps which are ignited one by one by an up- ward push of the thumb. Each light burns halfaminute A coat hanger which you can carry in your pocket. It is about two inches long but will hold sixty pounds. It is easily pressed into the wall or woodwork 210 At left: These steel match holders are equipped so as to accommodate the ordi- nary parlor match or to hold two boxes of safety matches. They are fast- ened on the kitchen wall A cast-iron garbage _ receiver built into the kitchen wall so that the front opens into the kitchen and the back upon the rear porch or into the back yard Housekeeping Made Easy ; 3 : d ee ee eT ee vee eben Fea ee A folding stand to raise the dishpan a few inches if the sink is low. It may also be used as a rest for hot pans when taken from the oven In oval above: A vacuum- cup massaging device which has a grip nearly twice as strong as that of the ordi- nary type of vacuum cup Ice-grips composed of wooden handlesin which are set spikes, or teeth, will prove a conveni- ence in lifting ice from the dumbwaiter to the refrigerator Oe eee a a ae A broad flat knife of flexi- ble steel for turning pan- cakes, eggs, etc. Ithasa sharp edge and can be used for chopping vegetables Below: A mop head which locks over the mop cloth holding it securely but releasing it readily when it is no longer needed WINDOW FRAME SS TRANSOM juock BoLt/ OPEN SSS GUIDE ROLLER ROPES — ==, / LEVER LOCK GUIDE BRACKET PIN ROLLER A device without springs and with but a single operating cord for opening and closing casement windows, transoms, shutters, etc. 211 = Sas — most brilliantly visible are the Municipal at the extreme right; the |Pulitzer, home of the New ne ee ee a ? York World; then the mighty Woolworth, king of the skyscrapers; the Singer; the Adams’ Ex- press Company Building; the Banker’s Trust; and at the extreme left the Whitehall Building located upon the eleven salients of Fort Wood, upon which the base of the statue is built. Three batteries are located upon the roofs of small buildings on the island. One battery is just below the torch. The total number of projectors is two hundred and forty-six, each projector being equipped with a two hundred and fifty- Photographed for Popular Science Monthly by Levick Watt incandescent lamp. Each projector has its individual compensator to step down the two hundred and twenty-volt current to the lamp voltage. Both pro- jectors and compensators are mounted on specially designed pipe-framed conduits. The electric current is supplied by the Public Service Corporation of New Jersey. One of the fifteen batteries of projectors located on one of the eleven salients (angles) of Fort Wood, upon which the base of the Statue is built. There are twenty lamps in this one battery 216 Popular Science Monthly —— e an K TF 3 st . i You Can See Your Gasoline in This Service Station NEW departure in gas- oline. service stations An Electrical Wind Waves this American Flag on its Pole HE sight of a flag waving from its staff in.a seemingly quiet at- mosphere in Atlantic City recently puzzled everyone who saw it. Only after a careful examination of the flag and the pole did it become apparent that the pole was really « blowing the flag. The pole was a metal tube twenty-seven feet high and five inches in diameter at the top and nine inches at the bottom. It was set over the ex- haust port of an electric motor-driven blower, hidden from view by foliage. For a distance of nine feet from the top, the pole was perforated with two rows of holes drilled close together. With the blower in opera- — mameFY {or automobilists has been invented by Henry E. Maurer, of Springfield, Illinois. The patented device includes a system for the accurate measure- ment and dispensing of gasoline which allows the motorist to see the gas- oline that he is receiving. Furthermore -the dealer does not have to turn the crank of his pump as each gallon is measured out. The entire apparatus is operated by the vacuum process and eliminates any possibility of mistake in ‘giving ~an accurate ~ measurement. When the motorist drives up to thé station he receives his gas from two five-gallon glass tanks. These tanks are marked with gages*that are inspected at intervals and sealed by the in- waving motion shown in the illustration. spector. As the gasoline flows out of the ee glass receptacle the motorist is given A Simple Method for chance to see exactly what and Lo Sighs Pasteurizing Milk he is getting. The flow is automatic. tion. it was the blasts emitted through these holes that held the flag and imparted to it the The pole blows the flag whether there is any air stirring or not. The effect is the same even indoors NE of the most important contributions The gasoline is released by opening from the medical profession has been - a valve, which admits air to the jar. .the simple process of pasteurization. We Whileone jaremptiesthe other fills. can only realize what it has meant when we consider that of all the dairy cows in the United States, forty per cent have tuberculosis. It is therefore evidently very important that every bottle be pasteurized before being used; and if that has not been done by the dealer, it can be effected without much trouble in the following way: The bottles are placed in a wire basket and slowly heated in a vessel of water to just boiling. Here they ~ are left for five minutes; then they are again cooled by allowing cold water to run into the vessel. The bottles must then be stored at a temperature of not more than fifty degrees Fahren- heit. If the temperature should be just about fifty degrees, wet woolen cloths will lower it enough. ip tb ‘ fae ll | There is no guesswork in measuring your gasoline with this device. You can see for yourself by watching the gages how ‘much you are getting — a en Te a Popular Science Monthly Twelve Blind Men Go Bicycling on a = Curious Machine -°AT the Royal Normal College for the Blind at Upper Norwood, London, England, a multicycle is in use which will carrya team of twelve cyclists. It is com- posed of six two-wheeled members, each adapted for two persons, coupled together. There is a connecting bar between each successive pair of wheels to form a complete train twenty-eight feet in length. Obviously the machine must be guided by a person who can see, This person is in the second seat. The slightest deviation to either side of the front wheels is trans- - mitted through the coupling bar to the second pair of wheels, the drivers of which can actin = concert, thereby conveying the same information to the third unit, and so on to the end. The eas sharpest curves can easily be N if: rounded. Often long excursions = are taken into the country. On ee one occasion blind men made a trip to Brighton, one hundred miles distant, in ten and three-quarter hours of actual running time, or an average speed of nine and three-quarter miles per hour. In this way, although each man has all the enjoyment and freedom of motion which is obtained in riding a separate bicycle, the balance is preserved just as_ surely as it would be in a long, narrow, twelve-wheeled truck. Moreover, the ap- pearance presented is not that of blind men being conducted on an outing. To the average observer, the riders are twelve normal men working individually and in perfect unison. None but the afflicted can realize what this means to the blind. rhs) poe ~ os : = Soke By drawing the magnet over the face of the plate the ; SS metal semicircles d F. may- be made to we slide along and ar- ) range themselves in 4 : any desired design Plate for Making Designs with a Magnet NEW game that takes advantage of the child’s delight in playing with a magnet is so constructed that letters, numerals, and other designs may be worked out. The essential part is a slotted metal plate. In each slot there is suspended a semicircle of silvered sheet metal, which slides freely through the slot but cannot drop out. The semicirclés are all turned in the same direction. - By drawing the magnet over the face of the plate they may be drawn to the front so as to make the design desired: The game is not only amusing but also may be used to teach the younger children the form of the different letters and numerals. An ingenious boy with some knowledge of the rudiments of constructional drawing can make any number of designs with the device and will derive much pleasure and practise from it. As an amusement for a youngster convalescing from an illness the idea is excellent, for it will keep his mind employed without in the least tiring Twelve blind men enjoying an outing on their multicycle. The element of danger from falls is practically eliminated him or over-exciting his im- agination. 218 Putting the Finishing Touches to a Collar by Machinery HE home of the first collar, Troy, New York, is also the home of the latest improvement in collar machinery. By the new power-driven finishing machines manufactured there, three distinct opera- tions are now performed where only one was made previously.» The machines con- tain four attachments, each consisting of a lower and upper mold. The thickness of the sides of the cup-shaped lower mold is equal to the thickness of the tie-space that is required between the two bands of a collar. When two collars are fitted to two of the at- tachments and a lever is pressed, the upper molds of the attach- ments are automatically pressed downward against the two collars. At the same time, steam is admitted be- tween the two molds as they press against the collar. The action of this steam for only a few seconds causes the starch to soften so that any starch cracks that may be present are deftly removed as their edges heal together. The thickness of the inner mold pro- duces the tie-space. The pressure of the molds smooths the collar and at the same time makes it round so that its two points will match when the collar is closed. All this is done in the one operation in five seconds. While this is going on, two more collars are placed on the other attach- ments, and while these are being “finished,” the first two collars are released. In this way no time is lost and as many as twenty collars are done in one minute. A collar-finishing which performs three different operations within five seconds A silver fork or other metal point does as well as a pencil on this paper Popular Science Monthly The Ever-Popular Pickwick Chair and Toy Table HE Pickwick chair is the most popular piece of furniture in the nursery. The chair is of wood, carved and painted like a seated figure, the arms and hands forming the chair-arms. The seat lifts and toys may be stowed in, the chair, while shirred cretonne pockets, which look-just like Mr. Pickwick’s own coat pockets, hang down at each side to hold toys. The toy table is long and narrow. Its top can be lifted up. Writing on Coated Book ~ Paper with a Fork OST persons are sur- prised to learn that an other metal forms write on coated book paper almost as clearly and easily as the lead pencil. This action is not chemical but me- chanical, though some scientists argue chemical action. Coated book-papers are treated with a sub- stance that’ may be readily rubbed off; or the position of the particles of the substance may be so changed in their relation to the’ surroundings that they do not reflect the light. Thus they give the part so changed by the metal a black appearance, similar to that of lead. Upon examining the writing under a microscope it particles of the metal. that have been rubbed off, or any evidence that the paper itself has undergone any chemical change. aut Platinum also marks the paper. This is proof pos- itive that the action is mechani- cal, because plati- num resists all chemi- cals except nitric and hydrochloric acids mixed (aqua regia). ordinary silver fork and. strongly in favor of is impossible to find any: ES ae ee a a ee a Le hte ‘ ( . Millionaire Vagabonds ~The American millionaire finds a substitute for his trip to Europe \ of Florida’s Waters By A. M. Jungmann | ie __ OSES “cre es rin : The houseboat of a millionaire is really a kind of luxurious river steamer. This one is a one hundred and thirty-foot craft which can carry two thousand five hundred gallons of gasoline HEN we wish to think in the superlative of luxury, our minds, curiously enough, hark back to the glories of the ancients—Nero fiddling to the accompaniment of burning Rome; Cleopatra wooing Mark Antony as they drifted down the. Nile in her. slave-driven silk-hung barge. Yet it is safe to assume that the most gorgeous queen of history would have paled with envy could she have compared her barge with that new toy of wealthy America—the power house- boat. Yet these same houseboats may not ‘be such an extravagance as they seem. It may be cheaper to move than to pay rent or taxes, when you can afford to live in a floating palace. A few years ago the general conception of a houseboat was a square, rather ugly structure, mounted on a number of barrels lashed together. Today the modern houseboat is a sort of glorified combination of a Fifth Avenue mansion and the latest cry in steam yachts. Since the war broke out in Europe, many of our wealthy pleasure-seekers have been forced to forego their annual European pilgrimage. Our own resorts, especially in the South, do not afford the luxurious accommodations that the American million- aire has been accustomed to obtain on the other side. And so the war was followed by a boom in power-houseboat building. Larger than ever is the fleet of these boats that has gone to Florida this winter. Most of them are equipped with gasoline engines which enable them to make the trip under their own power. The houseboat of a millionaire is really a kind of luxurious river steamer. She may be anywhere from fifty to one hundred and fifty feet in length, and she may accommodate from ten to forty wealthy vagabonds, depending on her size. Do not confuse the houseboat with a yacht. A houseboat is not so much a ship asahome. Her living and dining rooms are commodious and bright. A number of the staterooms are sure to have private bath- rooms, with all the requirements of vanity. Su¢h a boat is lighted by electricity. She has a hot-water plant, a ventilating plant and an excellent refrigerating system. The fish caught by the guests are kept absolutely fresh in a special tank supplied with fresh sea water. Of course the guests want to talk to one another without screaming down the corridors, and so a -telephone system is usually considered indispensable. Besides there is an alarm system, to be used in case of fire or accident, an electric bilge pump and a complete fire fighting apparatus. A big houseboat, a one hundred and thirty footer, will carry 2500 gallons of gasoline, for which a type of tank has been devised with filling and vent pipe so arranged that no gasoline will get below deck when the tank is filled. Her large refrigerator will carry 7000 pounds of ice. Storerooms, pantries and lockers are so big and numerous that she can carry supplies enough for months. If her owner desires to escape civilization, all he has to do is to sail away for a year and a day and have all the comforts of life without any of the modern inconveniences. There are numbers of these houseboats which have gone to Florida this winter. Some are wonderfully complete and com- fortable though only half the size of others. All are able to travel under their own power. The majority have gasoline motors. 219 The Styles in Our Modern Houseboats Run the Gamut ; Z, We Je a Pe ee ie Ss SHV Above: A modern bungalow type of houseboat, in which the only economy is that of space. It is furnished in the same style as if it stood on solid earth ti. EEE Baca Cdddddddde N SS At left above: Some city apartments are smaller than the dining-room alone on this commodious houseboat. There | are even fresh flowers for decoration . _ At left: This bedroom is an actual photo- graph of the supplanter of the seaman’s berth. There is nothing suggestive of qi | ship’s furnishings anywhere in the room ».- Below: A sailing vessel which has been Y ' converted into a luxurious houseboat. The lll Z g Majority of these boats, however, depend on gasoline, not on the wind Above: There is solid comfort in the living-room which is modeled after the “den” at home. Note the high ceiling and the many little details which speak of personal ease and enjoyment. The sunlight streams into this room not through a porthole but through a real window of the Luxurious in Providing for Vagabondage de Luxe At top above: The millionaire vagabonds may desire to escape civilization but they can’t get along without their luxuries. The verandas of the houseboats are not planned with regard to high seas; they are equipped with lavish furnishings and the owners hope for unvarying calm At left above: A member of the larger family of At right above: The kitchen of the houseboats which has all the modern conveniences luxurious power houseboat is as com- of sailing. A houseboat of this size carries store- pletely equipped as that of a modern rooms, pantries, lockers and supplies enough for restaurant. Two stoves are shown, one months of wandering far away from civilization an oil stove and the other for coal 221 Eternal Vigilance on the Part of One Hundred Food Inspectors Photos Amer. Press Assoc, To protect New York city’s four millions against food contamination the Department of Health employs a corps of one hundred inspectors. The photograph above shows an inspector condemning a quantity of Pineapples after pouring crude carbolic acid over them to prevent them from being used Above: Smelling separate pails — of yolks and whites of eggs to detect mustiness and sourness. The eggs are later mixed and frozen in thirty-pound tins for use of bakers and confectioners At left: Carcass of forehalf of beef condemned by a veterinary . as tubercular. An inspector is spoiling it with carbolic acid, af- ter which it will be destroyed . Is the Price Which New York City Pays for Food Safety = Inspectors ruining a barrel of spoiled fowl with kerosene oil before the owner could place it in cold stor- age. All rotten meat is removed and shipped to Barren Island. Here it is converted into fertilizer Below: Examining a dough-mixing machine in a bakery. Bakeries in the tenement districts require con- stant watching. But thanks to modern machinery, conditions are better than they ever were before At right at bottom of the page: Inspector examining “‘candled out” eggs to detect “too close” candling, which means that eggs with only a few slight spots have not been elimi- nated from among the sound eggs Below: Passing on German carp. The gills must be a bright but natural red to assure the inspector that they are fresh and unpainted. Fraudulent dealers used to paint the gills with a carmine solution 223 The upper tray slides on the sustaining rods so that it extends over the bed to just the desired location. The lower one is stationery A Double-Decked Serving Tray for the Sick Room NEW wheeled serving-tray has been devised by John J. Moore, of Batavia, ’ New York, for dining-room and hospital service. It is especially useful in the sick room, as the upper tray member may be extended to one side over the bed on which the patient who is to be fed from it is reclining. In hospital service the superposed trays are especially useful for segre- gating medicinal preparations and the like from surgical instruments, bandages, etc., and thus reducing time and labor incident to many separate operations. Moreover, the. supporting frame of the trays may be quickly ele- vated or partially collapsed whenever desired. Although one’s first thought is of the sick and convalescent when an in- vention like this is brought to the attention, it must be admitted that there are times when the well and hearty are appre- ciative of a breakfast served in bed. The serving tray could be “laid” attractively and the coffee pot and cover- ed dishes kept piping hot on the tray below. .e y. i in the other. you beat both at o he yolks are in on oe i ee Turn the crank and Popular Science Monthly Truth Crushed to Earth Will Rise Again But a Lie Can’t Be Crushed At All F you have noticed the big wooden clocks that are hung as shingles outside jewelers’ windows, you will have noticed . that they point generally to 8:18. The story has often been told that the patri- otic sign painters paint the hands in this position for the purpose of commemorating the time ot President Lincoln’s assassin- ation. But—as the Tliree Wise Men — would say—don’t believe everything you hear. This has recently been investigated by some interested men with the result that the story, patriotic though it is, could not possibly be true. In the first place, Abraham Lincoln was shot over an hour later than 8:18. But more than this, jewelers’ clocks were pointing out 8:18 twenty-five years before that un- fortunate night in April, 1865. They were placed in that position to give the greatest possible space for the jewelers’ names and for their advertisements. Finally it was — found out that the story itself was merely a “frame up” by two newspaper men who ~ thought they would test a pet theory of — theirs—that a plausible lie, when once in circulation, will continue to go on forever. Beating the Yolks and Whites at the Same Time | DOUBLE egg-beater has been © devised by a Seattle man— — Nicholas Condogeorge—by means of which the whites and yolks of eggs, in two separate bowls, may — be beaten simultaneously. This saves a great deal of time, and — is an advantage which is of © special importance to cooks — in hotels and restaurant — kitchens. 4 The two beaters are sup- ported from a frame having © a U-shaped handle which may be grasped by the left © hand, while the beating handle is rotated with the~ right hand. The beating handle or crank is at- tached to a_ vertical gear wheel that meshes with a gear attached to one of the _ beaters. This gear in turn meshes with other gears that drive the companion beater simultaneously. eee ee e bowl; the whites mce in record time a re Ce =< -' .. Snow: A Curse and a Blessing The same blanket of snow in high mountains that sends destruc- tive avalanches down into the valleys will serve to feed irri- gation streams in the spring and make agriculture possible a po re Be FS a : =, ed Sa il Se ie cla A The heaviest snowfall in the whole country, as far as known, occurs in the high Sierra Nevada, of California, where the houses are often buried up to their eaves. This snow, melting, furnishes most of the water for irrigation in the California lowlands F snow were only a thing for children to ] romp in and poets to prate about, the United States Government would prob- ably not be minded to publish throughout each winter a weekly snow bulletin, com- prising telegraphic reports from all parts of the country, nor would it send out its experts to probe and map the mountain snowfields for the purpose of determin- ing the probable water-supply from this source. A good snowfall chart of the United States will show you that, in a normal winter, the total amount of snow falling in various parts of the country ranges from nil in southern Florida and parts of California to more than one hundred inches in northern Maine and on the southern shores of Lake Superior, and to three hundred or four hundred inches in portions of the Rocky Mountains and the Sierra Nevada. The occasional heavy fall of snow pre- sents a problem to the street-cleaning authorities in our great cities that is not yet fully solved. Only a few years ago the uniform method of dealing with this prob- lém was to wait until the storm was over and business effectually tied up; then press into service as many men and wagons as possible, and gradually dig the city out. The tendency now is to begin work as soon as the snow has covered the pavements if the indications point to a continuance of the storm. A most important advance consists in a recognition of the extent to which the sewers can be utilized in snow removal. While some authorities advocate flushing the snow into sewers with a hose, the method which has recently proved suc- cessful in New York City is to collect it in wagons and dump it into the manholes, under proper supervision to prevent an unnecessary amount of solid matter from being dumped along with it. Two cubic yards a minute can be shoveled into a twenty-four-inch manhole, and, under ordi- nary conditions, it is found that the entire amount is melted within three hundred feet of the manhole by the relatively warm water in the sewer. The cost is a small fraction of that entailed by the old method of hauling to riverside dumps. 225 226 Removing Snow from City Streets Several devices for’ melting snow on the streets have been introduced or sug- gested, but, except for cleaning side- walks, they have not come into practical use. hot-water: A special car, equipped with steam pipes for melting snow, has been successfully used by the Penn- sylvania Railroad in its yards at Phila- delphia, and a simi- lar device would probably be suita- ble for municipal use. The snow is shoveled into a shallow re- ceiver in the upper part of the car, where it is im- mediately melted by the steam. The lower part of the car: .forms * 2 tank in which the water accumulates, and from which it is drawn off and emptied into sewers when the tank is full. Many and formidable are the snow prob- lems with which the railways have to grapple, and the solutions take the form of snow sheds, fences, ploughs of various types, flangers, gasoline torches for melting snow in switches, etc. Notwithstanding all these expedients heavy snowstorms still result in tieups or the serious demoraliza- tion of schedules. One plan is to flush the streets with - _ Popular Science Monthly table and chart, the depth of snow on the - ground at a great number of places through- — out the country, and also contains a review of the snow conditions of the preceding week. This is of value to the railways, shippers, and everybody interested in crops subject to winter- killing, winter wheat. How Snowfalls Are M easured One of the most interesting snow problems—and_ one that has attracted much attention in recent years—relates to the measurement of snowfall in the mountainous regions which comes most of the water used for jacent lowlands. The mountains not only receive much A snow sampler is a metal tube or bore which is forced down into the snow to secure a sample. When the snow is shallow a bucket is used more snowfall than the lowlands, but they retain it much longer. Thus a mountain constitutes a snow reservoir, which feeds the water reservoir constructed by the irrigation engineer. In connection with the reckainaaee projects it is important to know how much snow falls, from year to year and also on an average, over the watersheds from which irrigation watér is supplied. The Weather Bureau has accordingly established, in Special warnings are issued by the Weather Bureau when- ever a heavy fall of snow is in prospect. These are interest- ing not only to the railways, traction companies and street cleaning authorities. but also to stock-raisers on the western plains, where timely notice of an approaching snowstorm makes it possible to get the cattle in from the ranges and save them from starvation. The Snow and Ice Bulletin which the Weather Bureau publishes weekly during the winter shows, by means of a Stock-raisers throughout the west and northwest are severe sufferers from snowstorms. Special warnings are sent to them especially of the west from irrigation in the ad- Se a a ee Popular Sones Monthly addition to its regular stations (located mostly in important towns), about two hundred spe- cial snowfall stations in the mountains and foothills. The Bureau has also developed spe- cial forms of measuring appara- tus appropriate for such loca- tions. The relation of the depth of snow to its water content is quite variable. It has been custo- mary, when more exact deter- minations were impracticable, to regard ten inches of snow as equivalent to one inch of rain- fall, but this assumption is only correct for snow of average density. In problems of water- supply the depth of snow is of no consequence in comparison with the water content, and the latter can be obtained either by melt- ing the snow before measure- Ve ment, or by weighing the snow, The latter process is generally” |... much simpler and is the one ia utilized in the type of gage used =e by the Weather Bureau at its Samad ‘ . a rae mountain stations. it eae The Latest Fashion in Snow-Measurers The accompanying picture shows a gage recently designed by Professor Marvin, Chief of the Weather Bureau, suitable for measuring either rain or snow. At the top is seen a trumpet- shaped wind-shield, and in the middle the cylindrical can or collector into which the precipitation falls. . The can rests upon a central support, which can be raised or lowered for placing or removing the collector. In making an observation, the can and its contents are removed and weighed by means of a spring balance, grad- uated to give the rainfall directly in inches and hundredths. The of gage here shown is used for daily observations, but a modified form, with much enlarged collector, is used where observations can only be made at long intervals—in some cases only once a season. In this gage oil films are sometimes used to prevent evapo- ration. Besides snow gages the Bureau uses snow stakes for measuring the depth of snow at various points around the station. The latest form of snow stake consists of a heavy 207 The Marvin gage for measuring rain or snow. At the top is a trumpet-shaped wind-shield and in the middle a cylin- drical can,“or collector into which the precipitation falls cypress stick of square section, painted white to minimize radiation effects, and bearing on one of its faces ascaleof enameled iron, graduated in inches. In the picture of the measuring stick on page 229 the num- bers attached to the scale represent tens of inches; I means I0 inches; 2, 20 inches; etc. These graduations can be readat a distance by means of binoculars or a telescope. The stakes are permanently installed in appro- priate locations. Lastly, the ambitious attempt has been made in recent years to ascertain, early each spring, the total amount of water available in the form of snow over wild mountainous tracts adjacent to certain irrigation projects and remote from the fixed stations. “Snow surveys” of this sort were first carried out by Professor Church, of the University of Nevada, in the Sierra Nevada, and by Messrs. Thiessen and Alter, of the United States Weather Bureau, in the mountain- ous districts of Utah. Whole Districts Buried Under Snow In the region adjacent to the line of the South with Reno, Nev., th season. The local effects of such a ee a —_— y WS ify \\\ if \ Scientists on Snowshoes The snow surveyors travel rapidly over the watershed, often on skiis or snowshoes, carrying with them a “‘snow sampler’ and a small spring balance. The sampler is a metal tube, of small bore, which is forced down to the bottom of the snow in order to secure a sample. The Marvin sampler, used by the Weather Bureau, is two and three-fourths inches in diameter and comes in various lengths. One end is armed with a.serrated cutting edge, so that it can be forced through icy incrustations, or ice _ itself in the snow beds. The tube is gradu- ated in inches. When the tube is with- drawn the section of snow remains in it, and the whole is weighed by means of the balance. Several hundreds of measure- ments are made on different parts of the watershed. An alternative plan, suitable for shallow beds of snow, is to shovel the snow into a bucket and weigh the latter with its contents. These methods depend upon the fact that a given weight of snow represents a definite amount of water, whereas the relation between depth of snow and water content is widely variable. Popular Science Monthly Se pits ww 4 : 1 s Nie 3 Ky 2 oF - J : 3 WE e DETAIL OF AUGER. tiie = Z MAKE OF Sle GAL mRON(083) a = ae DBD z ' w= ui ih 32 z2 i 6 = f ey 3 WOODEN Pin |. jz oe 4 =e at 1 454 e > t =z *s <= | is oe ES a9 sz rs 96 iM ‘La san e2 SNOW SAMPLER, itis 2? z : KADEL PATTERN vis coat e E NOTES #4 Ks se Q - BEND DOWNWARD p4is = uz. © - BEND upwaRD 2 ~‘P\i4 bo =i = . EL @ Cc — MRON CORNER BRACEL= nek 2.2 PIN. A fo yur & - cut FROM CiRCUM- 34 ergs mies FERENCE TO STICK. : 2a- . = - < : ; * 8 s 4 - : 8 4 LONG Rivers | . j : a3 ver Vii 2 te Above is the Kadel snow sampler which is an auger and measuring stick combined. The diameter of the tube is such that one pound of sngw represents one inch of water At left: The Marvin sampler. One end of the tube has a toothed cutting edge so that it can be forced through icy incrustations in the snow beds. It is graduated in inches Mr. B. C. Kadel, of the Weather Bureau, has recently devised a snow sampler having a bore of nearly six inches, which is much larger than in the Marvin instrument; it is provided with an auger, which, when screwed to the base of the tube, constitutes a bottom for retaining the snow. The diameter of the tube is such that one pound of snow represents one inch of water. This ingenious instrument unfortunately labors under the disadvantage of being too heavy to be readily portable over the mountains and in districts where the trans- portation facilities are likely to be cut off entirely during the very time when the snow sampler is needed. There are places in the mountains where more than five hundred inches of snow falls during an average season, and where the exceptional depth is nearly eight hundred inches or more than sixty-five feet. This is in the Sierra Nevada, of California, in the region adjacent to the line of the Southern Pacific Railway connecting Sacramento, Cal., with Reno, Nev. The railway company is kept busy shoveling the accumulations off its thirty-two miles of snow-sheds. mite. = ae MOVABLE JAW SPRING Tails are more than mere adornments. This one, for instance, serves the pur- “ pose of setting the trap jaws of the imitation dog Popular Science Monthly Automobile Engineers proposes that there be a list of uniform names _ for automobile parts and that these names be standardized. To this end the society has published a report-on. automobile termin- ology. The automobile is dissected into nineteen general divisions, and all the parts in each division are given their standard names—making a total of nearly seven hundred names of separate parts. The name “‘engine,’’ notes the report, should be used rather than “motor,” to- avoid confusion with elec- cae POSITION 3 _“/ tric motors and to secure a ne = Lower freight rate. Thus it will be ‘‘engine-car”’ in- . ~f---- a DBs BAIT —_BAIT LEVER He Eats Dachshund Charlie. "Em Alive © WESTERN inventor, Edwin S: Cun- ningham, of .Mansfield, TIll., has devised a trap which, for originality of structure if nothing else, deserves mention. He has constructed a wooden figure of a dog (with the tail changed it would make a realistic-looking alligator) and has placed within the interior of the humble CAUIRE, a strong rat-trap mechanism. Although the tail appears to serve only as an adornment it is really the most impor- tant part of the trap. By- moving it down: the trap is set. .When the mouse steps on the bait-plate, which takes the place of the dog’s: tongue, the upper part of the jaw comes down with a thud and the tail goes _ up. A strong spring operates it. Standardizing Our Automobile ; Shop Language EREAFTER people talking about their automobiles will be able to under- stand each other. A_ nut will be called a nut and abolta bolt. When repairs and replacements aré or- dered, manufacturers. will not need to spend the better part of the day figuring out just what part of the auto- mobile’s intricate anatomy is wanted. In other words, the present chaotic condi- tion of automobile nomen- clature is about to be remedied. The Society of Gee TRIGGER stead of “motor-car.”’. WEIGHT ere tee Don’t Throw a Horse. Make Him Lie Down if it’s Necessary — 7 ETERINARY surgeons frequently have to throw a horse to perform an operation. As there is danger of hurt- ing the animal, specially devised shackles are sometimes ‘used, one form of which, shown in the illustration, seems to be especially humane and is very easy of operation. The arrangement is such that a pull on the forward ropes will draw together a front and rear foot and tend to raise both rear feet from the ground, causing the horse to lie down. The same thing can be accomplished by hitching the front ropes and making the horse step backward. One leg is left free to aid the animal in assuming a prostrate position without injury or undue strain. With this device only three of the aciinaite legs are shackled, one being left free to enable him to lie down rather than fall 4 But the — work is not yet completed. There are ' several groups still under consideration. _ Si Cie oe Soe oe ee a An Armored Motor-Car for the It is manned by acrew of three and equip- Navy ped with searchlights and machine guns In the tipping test shown below the car stood at thirty degrees with two wheels off the ground without tipping rine Corps, first of our services to use motor-trucks in war- fare, will be equip- ped with armored motor turret-cars for its use in tropical expeditions. 4 United States Ma- carries a crew of three men. It has wire- cutters for road obstacles, searchlights for night fighting, and machine-guns. The armor, sloping at forty-five degrees, will stop the bullet fired from a service rifle at one hundred feet. The turret has four gunports, allowing fire in any direction. This armored car will be carried aboard ship. When lowered into a motor sailer or sailing launch it will rest on joists placed fore and aft on the thwarts. The boat is beached stern first and the car is run ashore in fair weather over planks hooking on to the stern, or in bad weather by shear legs and a multiple block. In the tests the car took ditches and plowed fields and ran hub deep in sand. When tipped by use of a ship’s crane the The turret-car weighs five thousand pounds, travels forty-seven miles an hour, and When placed on a sailing launch the armored car will rest on joists placed fore and aft on the thwarts as shown car stood at 30 degrees, with two wheels off the ground without tipping. The uses to which it may be put are obvious. The Rubber Stamp Has Many Uses, Good and Bad T is not contended that the rubber stamp is exactly on the same plane of importance as the rubber tire, but in value of annual product these two commodities stand in about the ratio of fifty to one. The car owner’s annual contribution ag- gregates approximately $200,000,000. That of the stamp user is about $4,000,000. But in one particular the stamp far surpasses the tire—in number. There are 12,000,000 tires in use in the United States. to-day, while of rubber stamps there are 100,000,000. The rubber stamp does its work faith- fully and cheerfully. In fact it has become recognized as a symbol of unquestioning obedience, and one statesman will charge another with being a “rubber stamp” in fealty to an opponent. The Wireless Detective How transgressors of national and international Radio laws are caught Photo. Central News A “Radio Detective’ which not only picks up passing wireless messages but also determines the direction from which they come and the probable location of the sender VEN in times of peace it is often of importance to locate wireless sending stations. When an amateur’s station is transgressing national law, or a spying government’s station is transgressing inter- national law, a “radio detective’’ will be of valuable assistance to our government. But in time of war, an instrument that can not only intercept wireless messages but can also locate the senders, will be of great strategical importance. The photograph above shows such an instrument which has been brought out by Frederic Koester, a young experimenter in the United States Bureau of Standards, of the Department of Commerce. paratus picks up the passing radio mes- sages and, at the same time, indicates the direction from which they come. By listening to the same message with two instruments of this kind placed at two different points, the position of the sender may be definitely determined. It is neces- sary only to mark on a map the two posi- tions where the instruments are receiving the message and to draw two straight lines in the directions shown by them. The place where the two lines cross on the map will indicate the desired spot. The ap-, Motion-Pictures Tell South Americans of Our Industrial Development O acquaint South Americans with the industrial development of this country and particularly to educate them in typical American manufacturing processes, wel- fare work in industrial institutions, and other details of economic life, the commer- cial attaches in the Latin-American coun- tries are exhibiting motion pictures in their respective localities. The pictures are being given under the auspices of the Bureau of Foreign and Domestic Commerce, but the films are obtained through the Bureau of Commer- cial Economics, an unofficial organization with headquarters in Washington, which has on hand a large number of films showing various phases of American industry. The films which the Bureau thinks most desirable are sent to the commercial attaches. In addition to educating the South Americans along American industrial lines, one purpose of sending the films is to stimulate interest in a much more extended campaign by which American manufac- turers may have their films displayed for advertising purposes: - wees se Se! SSC ee ee Wall Street Goes a-Farming | Raising crops on the factory plan with four thousand hired . men By John R. Colter > — = = Getting teamsters is a chronic difficulty on a farm. for “big business.’”” Above is shown one of these W wie Capital undertakes anything, whether it be an exploitation ofa. mine, a mill, a chain of grocery shops or a transportation project involving a string of railroads—you expect scientific treatment, efficient management, and a certain daring grappling with problems never before solved. In tackling its latest important development job—the growing of things in the- goound—Capital has not gone about the work in any less thorough or scientific manner. The gigantic Oak Or- chard Farm, largest of muck-gardens in the Eastern states and possibly in the whole world, stands even to-day—when it is scarcely two years old—as an admirable example of what a great farm can be when conducted under the precise and systematic management of “Big Business.”’ _ They call it the “Wall Street” farm up in Genesee County, New York, but it would not blend with what is probably your con- ception of afarm. You would have to tour about in one of the farm’s automobiles for six or eight hours before you could get an idea of itall. Itisavast tract. It is nine miles by two miles, to speak roughly, for the general contour is that of a pair of saddle- bags. To pay off the men who work on the huge outdoor hotbed the paymaster makes ‘a sixty-mile trip. Oak Orchard Farm has its own telephone system, its own farm- machinery repair shops, builds its own roadways, counts its cattle on a dozen * sizeable hills, does its experimental seed- planting on thirty-five-acre lots instead of twenty-foot squares, swarms with labor- The “steel mule,”’ or tractor solves this problem “mules” hauling pea vines to a threshing station saving caterpillar-tractors and light steel “‘mules’’ in place of horses, plants onions and lettt&ice by the half-mile row—and_has its own canneries, storage cellars, garages and home-communities in the bargain. A gigantic country-produce manufacturing plant with a potential acreage of eleven thousand—such is the self-sustaining under- . taking with which the New York capitalists who-own and operate the Oak Orchard Valley bid fair to revolutionize the business of farming. Dynamiting Ditches to Obtain Muck Land Three years ago the great Oak Orchard Valley which lies just north of Elba, N. Y. (half in Genesee and half in Orleans County), was a vast marsh, overgrown with dense underbrush and studded with forests of heavy timber. It was at once a lumber- jack’s job and a drainage engineer’s job. Through the center of the marsh a colony of Adirondack lumbermen cut a path—they were specially brought down for the occa- sion. Behind them the engineers dyna- mited and dredged a ditch which would ultimately carry off the surplus water to Lake Ontario, fifty miles away. Lateral canals, feeders to the main ditch, were gouged out at distances of approximately two thousand feet. Thus the great bulk of the surface waters of the region were carried down the valley, leaving exposed several thousand acres of hitherto sub- merged muck-land—that superwealthy soil which produces truck-stuffs with lavish 234. Popular Science Monthly SHELBY WN Thee : : cone 2 BARRE CENTER : ee : i} e i eas = } r : Ps | Ae SHELBY. SS a ——\" me an <== L phi ("4 as - A bo eae = earn MOAT 4 \7 Gon a ALABAMA CENTER { “i 7 WHEAT VILLE < . = SOUTH ALABAMA SX Spay os : Booch 2 OAKFIELD ons y eee aN SCALE IN MILES Oe oN eS idea of this farm. fertility. Over sixty miles of drainage canals, criss-crossing the immense farm, have been constructed, so that to-day the muck region stretches for miles in every direction. In certain parts of the valley the reclamation work was accomplished in what is undoubtedly record time. One large patch, which in the Autumn of 1913 was practically a lake bristling with heavy trees, was transformed in nine months into a harrowed field, ready for planting. Drained of water, stripped of woods, ploughed, harrowed—and a lettuce crop harvested within the following three months—that is a record of engineer- ing and agricultural achievement which corporate farming may well boast of for a representative twelve-month’s work. The Factory of men. You weeuitel fave & tour about in an automobile for six or eight hours before you "could Longa any It is a vast tract nine by two miles and like a pair of saddle-bags in contour tillage, planting, cultivation and harvesting. The light and heavy tractors, employed instead of horses, do their work under gangs There are plough-foremen, and harvesting staffs on Oak Orchard farm, and they report to their immediate superior official just the same as a city factory sub- chief would do. Each unit of the intricate farm machinery with which the big hotbed swarms receives credit for every yard of work that itdoes. Each acre, under a cost- accounting system, as effective as it is unique on farms, is debited on the farm auditor’s book with its daily share of man- labor, horse-labor, machine-labor, ferti- lizer and its share, too, of the overhead expense. it proposes _ Idea A pplied to Farming But in the layout and management of the huge green- stuffs factory— that is precisely what they are making of Oak Orchard Farm —lie its most interesting phases. Every hundred -acre plot of soil re- where it stands after the crops vested and sold. Efficiency, especially wherever the precious muck- soil is involved, is the by-word inoperating the farm. For in- stance, the an- cient rail-fences which marked ceives. careful planning with regard to its farmhouse ; but The dwelling in the home communities as planned by the farm officials is not at all the ordinary type of is compact, have been cozy and attractive completely There is nothing inexact about . ‘the big farm’s,. methods ; to know just . have been har- — boundaries: Popular Science Monthly 235 before your eyés strike the northeastern cor- ner of the tract. On that corner stand the conical towers of the silos—fodder-storage houses—in which is kept the winter’s sup- ply of corn for the farm’s four hundred odd cattle. This stock-farm, a pretty large «. proposition for an - average farmer, is Mes however a mere side issue. _ Two Wet mi Tres eee ages — Some of the buiidings on the great fie wtich. has its own garages, power plant, snisching shops, smithies, maintenance shops, canneries, storage cellars and home communities discarded. It would waste a strip of muck at least a foot wide, they reasoned—and they would need such lengthy fences on the big farm that the aggregate loss of tillable- soil would be enormous. When it came to the labor problem and the horse-feed prob- lem, the officials did not hesitate to blaze a new trail in farm-operating annals. Of course all modern farms have a few tractors, put this corporate farm has them by the dozen. Not only does the “steel mule’’— light tractor—save in operation over the heavy-eating Dobbin—it saves the em- ployers from the ever present (on the ordinary farm) “hired man” problem. “We find that the young fellows of the community just love to handle a ‘mule’ and learn to take care of its mechanism. There’s something Twentieth Century about this way of ploughing, harrowing and general farm hauling that does not seem irksome. No labor problem because of discontent on this farm,” the officials say. ‘Getting teamsters is a chronic difficulty on farms; we use ‘steel mules’ and other tractors—and find no trouble at all. Electric light, run- ning water, phonographs, clubhouses, tele- phones, steam-heat and billiard tables in our farm-hand dormitories—we count these scientific ways of helping to solve the farm labor problem, too.”” Which is sound effi- ciency. A Farm Measured by Miles Stand on the hill where the headquarters camp is located, on the southern side of the big farm, and you can look for three miles over a level expanse of coal-black muck miles to the south lie a group of apple or- chards on the sloping uplands that surround the muck. Various orchard gangs, under trained foremen, run miniature water-tower machines down between the rows of trees, spraying with insecticides. It is but an in- stance of the minute care given every wisp of plant life on the big farm. Daily reports on the condition of each orchard, each onion How the drainage canals were dug. With the completion of each mile of dredged ditch, immense acreages of submerged muck lands of great fertility were released for tillage 236 patch, each seed-planting experimental plot go to the central office of the farm. Itisa corporation tradition that system shall be sovereign — and it is in Oak Orchard Valley. Naturally the new order of tilling—the widespread use of the caterpillar tractor and the ‘‘mule’’—has brought about a new order of barns. Oak Orchard maintains its own machine-shops, lathes, smithies, gasoline stores and maintenance-shops. The old- style rambling barn does not exist. Nor do they thresh their grains or their peas in a shed. The pea-crop of the farm is so large that several different pea-viner stations have been established. The vines are hauled to the various sta- tions and put through special pea-threshing ma- chines, the peas falling into tin drawers which are rapidly hauled by “‘steel mules”’ over to the canning factory which lies three miles from the muck-region—on the railroad track. The same principle of speciali- zation for the pur- poses of efficiency has led to the construc- tion of a uniquely designed building known as the ‘Ordi- nary Storage Cellar.” It is intended for Oak Orchard’s immense root crops, such as potatoes and carrots, and serves to keep the vegetables in perfect con- dition until such time as the market is high enough to assure a good profit. One of the hardest of unusual problems that the big farm has had to cope with is that of wind control. After experimenta- tion a large number of light, temporary fences—split-open fertilizer sacks strung on wires which in turn were supported by light wooden posts—were erected at intervals of two hundred and fifty feet. This form of windbreak, although ex- tremely cheap and very easily erected and removed, has proved very effective. 7 . Bes Osun icera V eal A condensing attachment which converts the steam issuing from the teakettle spout into distilled water and delivers it into a receptacle as shown below 2 a TUBE STEAM Popular Science Monthly A Simple Teakettle Attachment for Condensing Water ig Bes drinking water found in many places is unfit for use because of the presence of foreign substances such as clay and earth in suspension, salts of various kinds in solution, and innumerable organic bodies which cause sickness and disease. To purify such water by filtering is both expensive and unsatisfactory. On the other hand, no apparatus is available which ‘will distill water in an economical manner. To fill such a want a condensing attachment for teakettles has been de- signed by Eugene N. Baldwin, of Joliet, Illi- nois. It can be at- tached to an ordi- nary teakettle to condense the steam issuing from the spout and to deliver ter into a_ suit- able receptacle for use. . The condenser consists of an aluminum tube open at both ends, with an air- tight, water- tight copper tube mounted on top and two flexible tubes and a pipe for cold water attached to the bot- tom. In setting up the apparatus. the aluminum tube is- placed over the spout of the kettle, and the flexible tube or hose is attached to the cold water faucet. The steam emerges from the spout, enters the tube and, passing down it, is condensed by DISTILLED , WATER COLD WATER INLET TUBE OUTLET TuBE f= contact with the walls of the tube cooled by a cold running water. The condensed water flows into the receptacle where it is stored until desired for use. The distilled water may then be kept in this receptacle for a few hours. By so doing, the “‘flat’’ taste that the water has directly after being distilled will be to a large extent removed. The hardest water may be made soft and usable _ in this way. Of course it must be kept — closely covered until used. the distilled wa- A framework made of wooden arches fits over the bed and is covered by an ordinary blanket or quilt. Taking Turkish Baths in Your Own Home se Ee the person who dislikes being “fussed over’ and who yet enjoys or regards as necessary the Turkish hot-air bath,.a- recent invention will prove interest- ing. It is an apparatus consisting of a framework made of wooden arches which are joined together by wooden shears. These shears make the framework collap- sible and adjustable to any size desired. An ordinary bed blanket is used as a cover for the frame. Inside the frame is a heat concentrating, distributing and circulating chamber which is really a chamber within a cham- ber, the inner partition being separated from the outer by an- air-space which prevents the out- side chamber from be- coming dangerously hot. The heat is directed into the inner chamber and distributed through an upper inlet. It passes over the body of the per- son lying in front of it and the used air passes out through an outlet in the bottom of the chamber and is discharged through an Opening in the top of the outside chamber. Thus the circulation of air over the body is complete. The source of the heat is a galvanized iron a but rigid and it is easily collapsible drum supported on legs which telescope to any desired height. In this drum an alcohol burner is held. The drum is con- nected with the heat concentrating and dis- tributing chamber by a pipe through which the heat is directed into the outer chamber. - The device can be operated and regulated by the person taking the bath. The frame is light © The heated air circulates over the body and is discharged through a special outlet Is Your Closet-Room Scarce? Try This Type of Wardrobe N the large cities it is the day of birds’ nest apartments, light housekeeping and kitchenette suites, where closets are at a premium. Even in the suburbs and in the country, commodious closets are giving place to shirtwaist boxes and wardrobe trunks. However, a wardrobe has been designed by Carl A. Schlacter, of Manson, lowa, which takes the place of a closet and * may be made in such a way as to contribute to the decora- tion of the room in which it is used. It consists of a sup- porting framework which is covered, top, bottom and sides, with any desired material, such as cretonne, silk or linen, in color and design to harmo- nize with the other draperies or furniture of the room. In connection.with the upper part of the frame is a rod to accommodate hangers. In this way a dust-proof place is provi- ded for hanging garments at full length. Moreover it is collapsible. The frame is easily taken down and rolled or folded up so that it may -be stored away in the trunk and —- used on one’s travels, in hotels, summer resorts, or transient stopping places. Snap-fasteners are used to close the covering. Even the top piece is made to open up readily, so that the back of the wardrobe can be easily reached. Store- keepers and dressmakers will also appreciate this invention as a means of keeping fine dresses or finished garments protected. For such purposes the covering material should be chosen with regard to durability. 238 Even the Horses Must Have Their Individual Drinking Cups HATEVER may be the future of the horse in the com- mercial world, and however soon he may be displaced on the city streets by the ~ /} ubiquitous automobile, his claim to good care and kindly attention will always be strong. Hence the individual drinking cups at the public fountains for -horses are a natural se- quence of the fight against germs which has abolished the common drinking glass for people in public places. The ordinary drinking trough is a breeding place and distributing center for all kinds of horse- breeding germs. In many cases the fountains have been shut off, and a man has been stationed at each hydrant to give the horses water from a pail, which he cleans out with a disinfectant after each drink. The arrangement in the photograph is the latest and most satisfactory plan. The individual drinking cups are placed far enough apart to prevent the horses from touching each other as they drink. The water comes up through the bottom of the cups and keeps them constantly full and overflowing. The overflow is carried at once to the sewer through the openings in the large basin surrounding the cups. The constant flow prevents the water from freezing during cold weather and keeps it cool during the summer. In some places wooden covers are provided to fit over the large basin. This is easily pushed aside and readjusted by the driver and serves to still further protect the cups and keep the water cool and pure. The cups, the surrounding basin and the standard’ are all of concrete construction. There are no metal parts to need special attention. Water comes up through the bottom of the cups and keeps them constantly full and overflowing Popular Science Monthly Here’s a New Hat Style from Mexico! HE influences of our “scrimmages” with Mexico can be traced in many things, one of which seems to be a new idea about the way our army at the ‘‘ bord. might be hat- ted. A well- meaning Can- adian pro- poses a new style of hat which, so he presumes, can be used as well in a Mexican desert as in a parade on Fifth Avenue. In the one case, the hat is open- ed so that it forms a continuous covering over a soldier’s head, while in the other case, it is merely closed up so that it is converted into the more conventional brim-hat of parade dress. The beauty of the hat when it is so collapsed is, however, somewhat ques- tionable. The manner in which the conversion is made is nevertheless clever. When the hat is fully opened, the continuous covering is held in place by an aluminum framework which fits upon the head. When it is to be re-modeled, the ribs of the covering are merely collapsed inwardly at the hinges near their centers. Then the lower parts of the ribs are made to pro- ject to form the brim. A convertible army hat in the shape that is proposed for the tropics, and how it looks when re- modeled for Popular Science Monthly How Germany Manages to Feed Her Millions N each one hundred acres of cultivated land, Germany feeds seventy of her people, while Britain can only support forty- _ five. The two chief factors in the recent re- _ markable development of German agricul- ture, are her settled economic policy and her well thought out system of agricultural education. It was the belief that he was essential to the community and that his land would not be allowed to go out of cultiva- tion, rather than the extra profit on his wheat, that inspired the German far- mer to greater efforts during [the last ten years. The need for well educated men as managers of estates is more commonly recognized in Germany than in any other country in the world. Install a Motor-Driven Bootblack in Your Home SIMPLE contrivance for cleaning and polishing shoes promises to save time and the price of the daily “‘shine’’ for the busy man. The machine consists of a pair of brushes mounted at the sides of a central brush, as shown in the accompanying illustration, and operated by power from any ordinary electric light socket. The blacking is applied by hand with a dauber. Then the foot is placed in the space between the two end brushes and the power turned on. The foot may be moved about in any position in the allotted space, so that all parts of the shoe may be reached. For polishing, a flannel drum is provided, emade of three or four layers of flannel which sag when the machine is at rest but are thrown out by centrifugal force when the power is turned on. The foot sinks into this drum, which, re- volving at the rate of twelve hundred revolutions a min- ute, gives a high polish to every portion of the shoe. The machine is the invention of a Mani- toba lawyer. It is so constructed that the parts are interchange- able and easily slipped on or off, and there is nothing to get out of order or to be spe- cially cared for. The entire operation takes up just about a min- nte for each shoe. The mechanical bootblack that cleans and polishes a shoe in the twinkling of an eye 239 The Ferris Wheel Turned Into A Baby’s Carriage and the swings will work up and down BACKYARD can be changed into an amusement park for your children by a new type of Ferris wheel which can be pushed along wherever itis wanted. Itisa combination of Ferris wheel and carriage invented by a South Carolina man, Charles M. Calhoun. The side supporting wheels are made about five feet high, and are kept in position by long iron crossbars. Two hangers are pivoted side-by-side on two special crossbars mounted near the center of the central axis of the carriage and dia- metrically opposite. Hence when one hanger moves upward the other moves downward, and when one is near to the rear of the carriage the other is near the front-of it. In fact, the weight of one hanger always tends to balance that of the other, and very little effort is required to push the carriage along. One of the iron crossbars which hold the side wheels in place also serves as a handle by which to push it. 240 Weep STILETTO NEEDLE | CASE The sewing materials which the Eskimo women use for their elaborate needlework The Eskimo Workbasket Which Is Worn About the Neck HE Eskimo housewife wears her workbasket about her neck, which means that the Eskimo housewife is exceed- ingly industrious. | During the long winter months she has nothing more to do than chew blubber and make ornaments to adorn herself and her several daugh- ters. Some of the most elaborate needlework is done by these silent folk of the far North. Out of the toughest of hides and with the crudest of instruments they have wrought objects of great beauty and interest. The illustration shows the several parts which go to make up the work- basket. The needle case This is the stick of sticks. a combination umbrella, cane, and seat, whichever you need Popular Science Monthly is carved from a bit of driftwood. The thimble is formed from a piece of tough walrus hide. The comb is carved from a walrus tusk. The skewer-like stiletto is made of bone and is used for making holes in skins, as well as to close the wounds in seals and other animals, to prevent the blood from escaping. The needle is made from ivory; the thread is of reindeer sinew. The toggle is a bit of polished whalebone ornamented with bone : rings. These are strung together on a strip of walrus hide profusely decorated with ivory beads. The comb is probably used more often for getting the tangles out of ani- mals’ fur than for the arrangement of the women’s hair; for the custom of the Eskimo housewife is to smooth out her hair only occasionally, and then grease it so heavily with whale oil that it stays smooth indefinitely. When she is busy at other things, Madame Eskimo tosses her work- basket over her shoulder out of her way. Are You Tired? Then Sit on Your Walking Stick ONSIDER all the changes which the ordinary walking-stick has been heir to. Your grandfather’s stick was just a plain old piece of hardy hickory. But look at the stick which father carries. It has an electric lamp to illuminate the key- hole for him at night. It carries a cigar or two and a small box of matches in its spacious head—or tiny bottles of medicine, a dagger, a revolver or other fancied neces- sities. But with all these walking-stick accessories there is one thing father can’t do with his stick. He can’t turn it into a stool. Charles Jaquet, a subject of the German Emperor, otherwise known as the Kaiser, has invented a combination stool, cane and umbrella. It is the stick of sticks. With his cane you need not look about you for a seat when you are tired. Just extend the two limbs connected with the cane, pull out the collapsible seat, and sit down. The members which act as chair legs fold compactly against the cane; so does the seat, which is composed of leather or some strongly woven fabric. It is Curing an Auditorium of Echoes \ \ Vitis / Jy VAAL 1/4 // ARE LL / WAV 74S A Diagram showing the floor plan of the auditorium of the University of Illinois and the concentration of sounds under the balcony walls HE auditori- um of the “ University of Illinois was a veritable sound- ing board before its acoustic faults were remedied. Echoes and rever- Hairfelt padding mounted on thin furring strips over the dome and walls solved the problem for the University of Illinois aa Diagram showing how sounds di- rected toward an unpadded pen- dentive in the rear wall were reflect- ed to different parts of the hall but only faint re- sponses from pad- ded walls. The intense hissing sound of an arc light backed by a reflector gave more pronounced results. It showed One method employed for locating echoes. Sound was generated for the purpose inside the little house and its direction controlled by two megaphones that the padded walls produced a berations were so pronounced as to distress an audi- ence. Various methods of cure were con- sidered—the effect of padding and paneling the walls, the possible advantages of instal- ling wires and sounding boards, and finally, the action of the ventilating system. These were all discarded in favor of padding the walls with sound-absorbing hairfelt. Before the effective cure was found several methods of tracing sound were tried. One test was made by talking through a megaphone toward different walls. The sound was generated inside a small house and its direction controlled by two mega- phones, one being pointed toward a listener and the other toward a wall which gave echoes. No distinct echo could be obtained by speaking simultaneously into the two megaphones. The ticks of a metronome (a clock-moved pendulum for marking exact time in music) produced very little additional effect, but when a sharp intense metallic sound was tried, echoes were obtained from unpadded walls OAT marked effect in reducing the intensity of the sound. Before it-was decided to use hairfelt as an absorbing material, curtains and draperies were hung at critical points suggested by the reverberating sounds. Four large pieces of canvas were suspended in the dome. From an acoustic standpoint the audi- torium was in a much improved condition as soon as the curtains and draperies were suspended. Of course the architectural features of the auditorium forbad the con- tinued use of curtains. Hairfelt was finally adopted. Accordingly, one large curved wall was covered with strips of one-inch hairfelt thirty inches wide, placed vertically and thirty inches apart so as to leave bare spaces between them. Following this thedome above the arches and the double curved side walls and single curved rear wall above the balcony were padded. The felt was mounted on thin furring strips which were bent to fit the curvature of the surfaces. The lamp is connected with batteries secured to the harness saddle or to a riding saddle An Electric Headlight for the Up-to-Date Horse LD Dobbin is becoming up-to-date, or seems to be making an effort to do so in order to keep up with the automobile. . He is now wearing an electric headlight, which lets an on-coming vehicle know that he is lumbering along. For this he is indebted to William M. Cloninger, of Paris, Arkansas, who has invented the headlight shown in the illustration. The lamp is con- nected with batteries secured to the saddle of the harness or to a riding saddle for horseback riding. It throws the light on the roadway ahead and thus helps to avoid accidents. Horses are apt to be very much like people as to skittishness or steadiness of “- nerve in the dark, and it will be found much ~ safer to drive a nervous horse over a well- lighted pathway than it would be to coax him along a dark road at night. The lamp is provided with a reflector which has a double convex lens and is a part of a hollow post through which the conducting wire is lead. This post is riveted at its lower end to a curved metallic base which is secured to the upper part of the bridle. The lamp may be detached when desired and used as a hand lamp around the stable, the hollow post portion serving as a handle. Popular Science Monthly | A Soap That Blues the Clotnes | While Lathering Them ie Englishman’ has patented a new laundry soap which he claims will blue the clothes while lathering them for-washing. It con- tains tallow, caustic soda, sodium thio-sulphate and a suitable dye pigment. or not articles requiring more soaping than others will receive more than the desired amount of bluing, and whether the subsequent rinsings will remove the coloring obtained in the rubbing process. Keeping Hungry Rats and Rabbits Out of Sewers T has recently been discovered that such animals as rabbits and field rats are the cause of much trouble in sewers of the smaller towns. They search sewers for food.. Prompted by this discovery a manu- facturer is now placing on the market a protector which will not only keep out any inquiring animal, but which will also allow sewerage water to discharge just as freely as ever. His device consists of a heavy perforated steel cover, the weight of which is sufficient to keep it closed against an animal when the sewerage discharge is small enough to pass through the perfora- tions in the cover. But if at any time the discharge becomes heavy, the cover will be forced upward on its hinges by the water and a greater discharge area will be obtained. In this case the force of the water itself will keep out the rats. The drain is kept in place by anchor rods on each side The question arises as to whether aT eee Popular Science Monthly Are You Interested in Cellar Farming? Let the Parasol Ant Instruct You HE accompanying photograph shows the leaf-cutting or parasol ants of tropical America traveling on the branch of a tree to their subterranean home, each ant carrying a leaf in its powerful jaws. These ants are the most conspicuous, abundant and destructive insects of the tribe of fungus-growing ants which inhabit the territory thirty degrees north and south of the equator. On the other hand they are noted agricultural specialists, feeding upon mushroom-like fungus which they grow themselves in their cellars. There still remains doubt among scien- tists as to what the ants do with the leaves they gather. Some surmise that they use them as food; others that they roof their underground nests with them. But the real use they make of leaves, according to a recent book by Belt, entitled ‘The Naturalist in Nicaragua,” is to make a compost in which a minute species of fungus resembling the mushroom will thrive. On this they feed. In other words, Belt calls the parasol ants mushroom-growers and feeders. They do not confine themselves to leaves, he says, but carry off any vege- table substance they find suitable for the compost. They are very particular about the ven- tilation of their underground chambers, and they have numerous holes leading from them up to the surface. These they open out or close up, apparently to maintain a regulation of temperature below. If they had had special instructions in underground farming their methods could not be more scientific. They were probably nicknamed parasol ants because of the manner in which they carry the leaves which they gather. By N. Y. Zoological Society A swarm of bees found out too late that a telephone terminal box is no place for a hive Even Bees Should Be Careful Where They Locate a the illustration above, the object in the upper right-hand corner is a honey- comb. The black spots on it and on the floor below and on the coiled wires are the bees which lost their lives through poor judgment in the choice of a hive. They chose a terminal box of a telephone company, and as the manager was not in the honey business his principal concern was to get rid of the bees without insulting them. The fumes of bi-sulphate of carbon did the trick. The parasol ants carry leaves and other vegetable substances, sometimes several times their size, nicely balanced on their heads so that the entire body is shaded. This suggested the name 244 Popular Science Monthly The entire front axle, wheels, driver’s seat, battery box, and steering wheel are turned when this cotton truck rounds a corner Low-Bed Cotton Truck Steered by Huge Bull Wheel HE motor truck for handling bales of cotton, shown in the accompanying illustration, is not steered by the turning of the front wheels on their spindles. In- stead the entire front axle, wheels, driver’s seat, battery box and steering- -wheel mech- anism is revolved in relation to the center line of the truck. This is accomplished by placing the en- tire front assembly, wheels andall,within a huge internal- geared bull wheel attached to the side frames of the truck. The front wheels simply revolve on their axle but do not turn in relation to it, the steer- ing of the truck being done by turning the front assembly with- in the bull wheel by means of a gear in mesh with the teeth of the former. Thanks to this construction a truck can be utilized with a frame only two inches from the ground, yet it can be steered easily and turned in a remarkably short radius. A low frame is ne- cessary to facilitate the lift- ing of heavy bales. A truck of other tionally heavy load. Pee This double-caliper can quickly this kind can carry an excep- make measurements where an- would be Rubber Instead of Glass Eyes for Wounded Soldiers RTIFICIAL eyes of rub- ber are taking thé place wounded soldiers in Europe. The rubber eyes have the ad- vantage of being unbreaka- ble, and as they are of pneumatic construction they maintain an elastic contact between the eyelids and the back of the orbitary cavity. To make the new rubber product, a cast formed of liquid plaster is made of the orbitary cavity and from this is constructed an eyeball, the face being of vulcanite. The made of soft rubber, there being a space between the two parts which is occupied by air, making the eyes pneumatic. A Caliper That Makes Extraordinary Measurements THREE-PIECE caliper which looks © like an ordinary caliper bent back upon itself is the invention of a Chicagoan, Mr. Franklin J. Wolff. S-shaped pietes of steel pivoted together at their centers, and a small ma- chinist’s rule pivoted to the end of one of these pieces. - The cleverness of the caliper is to be found in the manner in which it can measure both inside and outside diameters which are so obstructed that an or- dinary caliper would be worthless for the purpose. For in- instance, an ordi- never measure the internal diameter of thesteam-valve body shown in the illus- tration; but the new duplex caliper does this very readily. the caliper is fully open- rule opposite which the pointed end of one of the S-pieces stops, and the worthless measurement is obtained. ae Te of the old-style glass optic for- front and back parts are It consists of two . nary caliper could: When - ed, it is only necessary to” read the mark upon the SP ere an eee el i ee ee ee ee ee a! ee a moving screen-sections before reach- The screen consists of two strands of chain carrying wire-covered frames Washing River Water for Power Plants Sifters on endless chains keep out the rubbish from the city mains since that would be too expensive. Instead it cleans the water of a river and pumps that up into the boilers and into the steam-condensers as itisneeded. To-day, huge moving screens are used in the larger plants throughout the United States, but only a year or so ago, they were using stationary screens placed in the supply-pipes which lead from the water. These were very unsatisfactory; for after heavy rain storms, the water would be filled with rubbish. In the new form of filter this trouble is done away with._ Here the screens are very much like platforms on a traveling-staircase. The water to be cleaned must first pass through the A POWER plant cannot use the water sy ing the supply-pipes. When the rubbish which is carried along reaches the top of the filter, it turns around with it on a large sprocket-wheel and then meets a powerful spray coming from behind. It is thus whipped off the filter into a trough of run- ning water, and from thence it ae At right: Diagram showing the details of the device and the course of the water over the screens is washed into the down-stream side of the river, out of the way. These filters are built in single units which occupy a space six feet wide and about forty feet long. . Where the water is let in from the river in channels more than six feet wide, a number of units, forming a battery of filters, must be placed side-by- side. In each unit, the screen-sections are placed close together on two endless steel chains driven by a small electric motor. ; GATE Bey LIFTS - - ~ Se WATER-WAY TO *. TRAVELING SCREENS Each unit is run by a small five-horsepower motor and is cap- able of cleaning sixty-nine million gallons of water per day Playing Checkers with Electric Lights Do you want to draw a crowd in front of your place? This bulletin-board game will do it CHECKER BOARD 4 {be thousand nine hundred and twenty lamps displayed upon the board and one thousand and twenty-four in the checker squares. NTHONY NELSON of St. Paul, Minnesota, is the inventor of a board which plays checkers and _ other games automatically. When the board is used for playing checkers it is capable of showing sixty thousand or more variations. The games or records are worked out on sheet brass and then placed on a cylinder which revolves slowly, requiring twenty- five minutes to make one revolution. The time required for each game is about eight minutes. The operation of the board may be described as follows: On the surface of the brass sheets is a series of grooves to con- form with the particular checker game being played on the board. Riding on the surface of these records, which are not unlike the records of the old-time music boxes, are ninety-six arms of a _non- conducting material. On the underside of the arms is placed a runner or needle on a About sixty thousand variations may be shown slant. These runners or needles drag on the surface of the cylinder as it revolves. Each arm is pivoted at oneend. On the upper edge the conducting bar is secured with the contact point at the free end. As the cylinder revolves the runners engage with grooves on the record, raising or lowering the arms. When the arms are raised the circuit is broken and the checker squares controlled by those arms are darkened. At the contact point is a groove extending longitudinally across the terminal board. Mercury is used to insure a perfect electrical circuit, as any failure of the lamps to light on the board would spoil the effect of the game. It requires three arms to control each square on the checker board. The color scheme is red and green lights for the checkermen, and a white light for the king. When the king is in play a letter “K”’ with a light background is displayed at the end of the cylinder. Anyone with OA — ee PO ee Te ee ee a ae Ss Popular Science Monthly the slightest knowledge of checkers can understand the game as it is played upon the board. There are one thousand nine hundred and twenty lamps displayed upon the board and one thousand and twenty- four lamps in the checker squares. The board is placed © in a perpendicular position. It can be seen at a considerable distance when illumi- nated at night. The squares upon which the checkers move have a circular opening or ring, behind which the lamps project. When in play each lamp has the appearance of a disk to conform to the size of a checker in relation to the checker square. In all checker games the opening move goes to the black. The first move is con- sidered an advantage, and checkers are reversed after each game. On the auto- matic board this rule is followed out. The green checker represents the black and moves first, playing from the bottom of the board the first game and from the top of the board the second game, reversing each game. The board may be used for other games, or for advertising purposes. SWITCH ARMS RUNNER OR NEEDLE ODO AAD OMQO Y TERMINALS The games or records are first worked out on sheet brass and then placed on a cylinder which revolves slowly. On the under side of the switch arms needles, placed on a slant, drag on the surface of the revolving cylinder SWITCH ARMS As the cylinder re- volves the runners engage grooves on the record. This raises or lowers the switch arms- and makes or breaks the circuit connection to the board lamps RECORD "MOTOR TO TURN RECORD Conveying Music by Wireless—A Modern Miracle HERE is more fact than fancy in that old song, ‘““There is music in the air.”’ You can lie in your comfortable berth on a liner speeding out to sea and hear the clear, limpid notes of Caruso as he siigs to an opera audience on land, many miles away. In the seclusion of your own home you can hear the world’s greatest artists and catch the spirit of the audiences to which they are singing, even to the minutest détails of applause, although the opera house may be in a distant city. These are modern wonders wrought by wireless. Not long ago the passengers on a steamer far out on Long Island Sound had the inter- esting experience of hearing musical selec- tions come in through their receivers. Only recently a group of wireless engineers and musicians held sensitive receivers to their ears and heard music which was conveyed to them by wireless from a distant part of the city. Briefly, this demonstration was made as follows: From the sound-box of a talking machine the music was led into the trans- mitter of a wireless sending station. Here it was transformed into an electric current which changed its direction several hundred thousand times a second. Then it was transformed into electromagnetic waves which traveled in all directions away from the aerial wires at the rate of 186,000 miles a second—the speed of light. The waves which reached the aerial wires of the re- ceiving station were then absorbed and converted back again into an electric cur- rent. The music was then led into the telephone receivers worn by the audience. Discovering the Well Known Saw Do you know that a rip-saw is really a series of chisels? Look at its teeth under a microscope and see for yourself saw andacross-cutsaw? If you do you know more about saws than do most mechanics. The fact is that a rip-saw is nothing more or less than a close-knit succession of tilted chisels. If a chisel is driven lightly into a board and pushed lengthwise with the grain it picks up a shaving. This is the principle on which the rip-saw cuts. To avoid side friction and binding, the teeth of a rip-saw are swaged or projected outwards from the saw-blade so that nothing but the extreme points experience any side friction. These extreme points are brought to needle- point sharpness. In other words, the tooth of each rip-saw cuts with its point and about is impossible to believe that there isany- — one half of the edge. body who doesn’t know everything about saws—plain, ordinary carpenter saws. A saw is the simplest thing in the world. It is made of flexible steel with little nicks along the edge that tear a narrow slot in a piece of wood. Ofcourse! Butdo you know the real difference between a rip- if this day and age of enlightenment it In the oval above, the teeth of the rip-saw are shown magnified. They are sharpened on the end so that they chip off.the ends of the fibers that run lengthwise of the channel, just as a chisel does, as is shown in the lower right corner of the picture. At left of the picture are the shavings as they appear when greatly magnified under the microscope, if the rip-saw has been correctly used . - -. 7 sss» Popular Science Monthly 249 Above: The action of a cross-cut saw is like that of a knife- blade. It cuts acrossthe grain At right in oval: The teeth of the cross-cut saw. Alternate teeth cut the ends of the wood fiber When a rip-saw has been used where a cross-cut saw should have been employed the shavings, or rather tearings, will look like this under the microscope Above: The sawdust shavings asthey appear under the microscope when a cross-cut saw has been correctly used The action is quite different with the cross-cut saw. If a chisel is pushed across the grain of a board it sticks and tears up the wood fibers. If a knife is used no great resistance is encountered. After drawing the knife across the grain along two lines the short cylinders of wood-fiber between the two can be easily broken loose, leaving a channel such as that cut by a saw. Now, if you substi- tute the tip of the cross-cut saw- tooth for the point of a knife and the leading edge of the tooth for the edge of the knife, you will see at once the action of the cross-cut saw. Alter- nate teeth cut the ends of the wood- fiber, and the following teeth eject the fibers as sawdust. The ripping process parts the wood-fiber and re- moves shavings, all of which is done so long as the outside leading edge of the tooth is sharp. The skillful workman learns to re- gard his saws as well as hisother tools as having spheres of usefulness pecu- liarly their own. To use a rip-saw where a cross-cut saw is needed may result disastrously in a fine piece of work. A comparison of the pictures of shavings and “‘tearings’’ will show the wastefulness of substitution. 250 Popular Science Monthly pe ay eR (ek } pe RE Making a Bungalow Unpopular with Night Prowlers HE evil-doer loves darkness rather than light, so the Good Book says, and a Toledo man has found in the saying a sug- gestion for keeping tramps, burglars and chicken thieves away from his residence. The house is square and stands on a knoll, so when he installed a powerful nitrogen tungsten light in a reflector at each corner, the whole place presented a_ brilliant spectacle, not at all attractive to marauders. The lights are controlled by push-buttons inside the house. What a Circuit-Breaker Push-buttons installed in the upper and lower halls and in the bedrooms control the lamps, and the grounds can be flooded with light when burglars or tramps are prowling turing plants. It can be ad- justed to open a circuit at a certain maximum current. When such a point is reached, the current flowing througha copper coil will pull up the plunger. This strikes against — fi the trigger and allows the operating springs to pull out the arm carrying the copper and carbon contacts. carbons remain closed until the copper bridge is lifted from its contacts. The final break in the circuit there- fore is made by the carbons, and hence the formation of an arc on the copper is pre- vented. This not only pre- vents the copper bridge from becoming fused, but it also prevents the “copper from burning up. There are numerous ‘other types of circuit-breakers serving many different purposes. There are under-load breakers for circuits that charge storage batteries, which open the circuit should the charging voltage drop and allow the batteries to dis- charge into the charging source; and there are others very much more elaborate in the powerhouses themselves. Such are the distant-control breakers, for instance. , Should any serious trouble occur the con- trol can ‘be operated and the switch opened by a push-button. ed Really Is N ordinary overload circuit-breaker is merely an automatic electric switch which is operated by an electromagnet for opening the circuit whenever the cur- rent becomes dangerously high. Circuit-breakers are installed wherever large cur- rents are employed, and if it were not for them many powerhouses would be burn- ed up because of the tre- mendous currents that would develop from accidental short circuiting. The accompanying illustra- tion shows a type of circuit- breaker that is now being used extensively in manufac- TERMINALS PLUNGER SET SCREW CARBON — CONTACTS COPPER BRIDGE- In this cir- cuit breaker acopper bridge is made to rise and open up the carbon contacts, the final break coming on the carbons OPERATING. SPRINGS © HANDLE FOR CLOSING The:. a ge Popular Science Monthly The Most Nutriment in the Least Space T often happens that a forest . patrol discovers a small brush fire, which, if not checked in its incipient stage, may soon grow into a great corfiagration that may lay waste to a whole country-side. In many instances the forest guard Powdered Cane Sugar Cocoa Butter dares not attempt to send for help but starts in to fight the fire single- handed. These lone battles against such great odds often last for hours until the fire is checked or until its smoke has summoned other patrolmen to the assistance of their comrade. Should the guard discovering the fire be forced to give up the ‘single-handed battle after several hours work in order to seek food, a fire which might otherwise have been checked while still in its infancy may sweep a great forest before it, resulting, not only in the loss of thousands of dollars worth of valuable timber, but of other property and, in many instances, of lives. - For this reason the Forest Service de- mands that every one of its forest guards must carry an emergency ration with him. The ration consists of three cakes resem- bling chocolate, each cake being one meal. The cakes are wrapped separately in tin-foil and are inclosed in an airtight tin case which may be carried conveniently in a saddle bag or coat pocket. The net weight of the ration is eight ounces. It is L The motorist takes his steering wheel with him when compelled to leave his car standing at the curb Every ranger in national forests must carry an emergency ration as part of his equipment the same as that included in the equipment of the United States Army. It is composed of 45.45% chocolate liquor; 7.27% nucleo- casein; 7.27% malted milk; 14.55% egg albumen; 21.82% powdered cane sugar; and 3.64% cocoa butter. Removable Steering-Wheel to Foil the Automobile Thief SHIP without a rudder is helpless, and so is an automobile without a steering- wheel. That seems to be the thought behind a new invention designed to prevent the stealing of automobiles left at the curb. The new wheel is easily attachable and detachable, so that the owner can take it with him when he leaves his car. ss The wheel differs from the conventional construction in that it has a hub in which is a slot which fits over a similar-sized block rigidly secured to the upper end of the steering post, as shown in the accom- panying illustration. The hub may be locked in place on the block in two differ- ent ways, according to whether the locking bar is integral with the wheel or with the block. In the first method, a small bar is pivoted at one side of the open end of the wheel hub and locked in position over a small pin at the opposite side. In the second method, a small bar is pivoted to the block at the center. As the bar is revolved about its pivot, notches provided at the ends of the bar on opposite sides fit over pins on the hub. To prevent a thief from fitting a wheel of his own of the same type, the hub is provided with a socket into which a pin in the block fits. New and Bigger Jobs for the Sturdy Truck MAL yh “Cs KG... A fifteen-ton steam-hammer moved a quarter mile on rollers by an automo- bile chassis. So heavy was the piece | of machinery that steel rollers placed under it were crushed like egg shells At left: A new jack to lift the wheels off the floor when the car is in the garage. The lip of the jack is placed under the hub and the lift is accomplished by a single upward motion of the hand At right: Preventing back draughts of dust with an air scoop. The wind pressure enters the scoop, placed at the front of the side- sae a car, and is forced out at the rear, break- f Sone ing up the air eddies that carry the dust | % A radiator shutter, operated An electric street-sprinkler with sprinklers in front, from the driver’s seat, keeps giving the driver better control. The three-ton the water from freezing truck carries an eight hundred-gallon water tank ORO a a a ee Se ee) and the Latest Refinements for The Louisiana State Board of Health has turned one end of it laboratory on wheels into a garage for a small automobile. The automobile is run into and out of its car on steel chutes Automobile covers of paper are used when the car is idle to keep out dust and dirt and prevent rusting and tarnishing of metal parts. The covers are made for small, medium and large cars, and the paper may be as heavy or light as desired —— At right: An eye-protector against wind pressure. It does not cover the eyes. The goggles closely fit the side of the face and extend outward and down- ward, thus forming an effectual windbreak without shutting out the air or affecting vision the Pleasure Car A folding blanket curtain for the Street cleaning in Bombay with a modern truck and a huge radiator, keeping the heat within barrel reservoir. This apparatus, minus the truck, is centuries and preventing freezing old. It somewhat resembles our own sprinkling carts How Are Photographs Made in Natural Colors? Nearer and nearer is the camera coming to perfect representatibn of the blush of the rose By A. +A LL photography depends on the fad- A ing of colors when exposed to a strong light. Of course, when a colored body fades, it would not be reasonable to suppose that it still had the precise chemical composition or structure that it had before fading. It is possible in many cases to magnify or accelerate the fading effects by steeping the partly faded object in a suit- able solution. In photography this process is called developing. After the develop- ment it is only necessary to dip the faded silver bromide plate or paper into a solution of “hypo” which dissolves the unfaded silver bromide and leaves the black or faded variety of silver to give the finished negative. Such a negative, however, is not a colored photograph, because silver bromide always fades to black. If a mixture of chemicals could be found in which the components of the mixture faded individually to different colors, then color photography would be a fact and not an experiment involving subterfuges. One difficulty has been that silver bromide and its allied salts are found to fade with practically only blue and violet rays of light. Hence, an ordinary photo- graph gives an untrue represent-* ation of a colored scene, be- cause the photographic plate i is blind to all other colors than the blue and violet. Ways have more recently been dis- LANTERN SLIDE PLATE / 2“ / PANCHROMATIC PLATE WITH SENSITIVE SIDE FACING LENS AFFECTS LANTERN SLIDE FILM ONLY Pil. P°ArFECTED BY ‘ LN BUSH WHITE RAYS 4 4 MRD ervci PRINTING FRAME Press covered of making silver bromide piates sensitive to all colors, but the chief difficulty now is that the silver salts so treated always fade to the same black color. great problem in color photography to-day is how to give a different color or tone to the different sets of silver grains faded by the differently colored rays occurring in a composite colored picture. — An exceedingly simple and ingenious method of two-color photography has been devised by Gurtner. Two grades of plates are required. One is a lantern-slide plate, which must be previously stained by means of a napthol orange solution. Such a lantern-slide plate is generally very slow. This plate is then placed face to face with a panchromatic plate in an _ ordinary camera and exposed through the glass of the lantern-slide plate. Turning to the illustration, it will be seen that a yellow patch in the chart photographed will send out yellow light rays that do not fade the silver of the lantern-slide layer because only blue or violet rays can affect it. Such yellow rays, however, in passing through into the pan- chromatic plate can affect the specially treated silver forming the sensi- tive surface of the plate. On the other hand, the blue patch in the chart affects only the lantern film. It cannot pass through to the panchromatic film, since, by staining the lantern film with an orange yellow dye, it effectively stops all blue or violet light from passing through. With the white light again, because it really has in it a mixture of yellowand bluerays, it affects both plates in the camera, whereas the black ‘ patch in the chart affects neither of the corresponding por- PANCHROMATIC NEGATIVE SLIDE NEGATIVE Thus the PAPER BACKING tions of the plate. Thus all the blue patches of the chart are photographed on one plate and all the AFFECTS UNAFFECTED BY BLACK PANCHROMATIC PLATE ONLY The Gurtner method of obtaining two-color effects by means of blue and yellow patches of color on the plates. It is also possible to obtain patches of white and a fairly good substitute for black by this method OFA. as cat alate al Popular Science Monthly yellow on another. This enables one to tone to different and appropriate colors those patches of the picture corresponding with different colors in the chart. It is then only necessary to combine the blue and yellow pictures face to face, to obtain the required color photographs. Should transparencies be made, to correspond with the separated blue and yellow colored portions of the chart photographed and then overlapped, it will be possible to obtain not only patches of white, where no color appears in either positive, but what will pass for a very good substitute for black where the very strong yellow of one plate overlaps the blue of the other. The panchromatic negative plate can be used for making a blue print on glass by exposing with a fixed-out plate, sensitized with blue-print sensitizer solution. The yeliow picture positive can be obtained by means of the lantern slide negative used with a collodio-chloride printing-out paper. The fixing should be done with ammonia to give a yellowish red positive. This positive should then be attached face to face to the glass blue-print and then a two-color photo- graphic effect will be obtained. You Can’t Find Your Brushes or Your Razor in Your Bag? Then Try This N automobile accessory which is intended to do away with certain trou- bles of the tourist, such as the mis- placing of brushes, combs. and other toilet articles, has been incorporated in the product of a Philadelphia ma- ker of bags and suit- cases. As shown in the accompanying illus- tration, it consists of a strap slipped through the slots in a band sewed to a leather flap which fits into the cover of the suitcase and is held in place by means of snap buttons. [Each toilet article is slipped into one of the strap loops. Then the strap is pulled tight to hold it in place. The loops are adjustable for larger articles by removing the strap from one slot and inserting it in the next. When filled, the flap is folded over into the cover and held in position by snap buttons. Each article fits in the loop of a strap which is adjustable to different sizes The cork bricks are laid in Portland cement over a sub-base of crushed stone or ashes Comfortable Cork Brick Flooring for Cattle HE search for a warm, non-absorbent flooring suited to the needs of horses, cows, hogs and sheep has led to the adop- tion of cork brick. The brick consists of finely granulated cork and refined asphalt, heated and thoroughly mixed, and then molded under préssure into bricks nine by four by two inches. The flooring is laid in cement mortar over a sub-base of concrete and crushed stones or ashes. Asa flooring for stables, cork brick has been found to be dur- —~. able in service, warm, easy under foot, and entirely sanitary. It is also practically noiseless, never slippery, readily installed, and moderate in cost. Breeders of prize stock cattle have been on the alert for several years for an improved type of flooring to protect their stock against changing weather. Cork brick flooring is said to give a maximum of comfort. One chief advantage of it is that it allows of frequent washing because it dries so quickly and be- cause it does not become slippery and dangerous under foot. Several large dairy farms in the middle west are said to have installed the new brick in their barns. 256 ibs meer PDE sit Shit: « © Underwood and Underwood, N. Y. : . Eight heavy shells suspended in a French bi- plane in which is no sighting instrument How French Air Fighters Handle Bombs and Machine Guns é EFORE the great war, no mili- tary officer really knew what was to be expected of bombs dropped from aircraft. There were radicals who not only denied that a dropping bomb could be aimed, but also declared that air bombs would be harmless because their destructiveness would be limited to a small radius. When the war came, the practical French settled the question by dropping their regulation artil- lery shells from large, weight-carrying aero- planes. They removed only the copper ring which in ordinary use guides the missile through the rifle barrel, adding instead a guid- ing windvane in the rear, to. photo make sure that the contact *™™ Ps fuse strikes the ground first. The accompanying photo- The slightest con- tact will cause the bomb to explode Popular Science Monthly graph, showing eight heavy shells suspended in a French biplane, is particularly inter- esting, because of the utter absence of any sighting instrument. Evidently the bombs are aimed by a trained instinct. The manner in which they are suspended sug- gests that they are first unhooked, that the contact-fuse is then ‘‘sensitized,”’ and that the bombs are dropped over the side of the fuselage, all by hand. A still more interesting feature of the picture is an aerial ‘‘gun turret’ for the machine gun. From such a rotatable machine-gun carriage more is demanded than from a battleship’s turret. The arc of fire is the whole horizon, and the gun must be ready to fire at angles of over forty-fiye degrees, up or down. That is why this mount is so very simple. It is really but a circular track around which the gun is shifted, and on any point of this track the gun may again be inde-- pendently turned through a wide arc, right or left and up or down. The problem of obtaining unobstrueted fire in nearly all directions has been solved in an ingenious way—the marksman simply stands in the center of the circular track. Fishing for Enemy Aircraft with an Aerial Death Hook A aerial bomb has been invented by Joseph A. Steinmetz, of Philadelphia, which simulates the old-time torpedo in that it is suspended from an aeroplane or dirigible by a long cable. There are three projecting arms or hooks on the bomb, any one of which coming in contact with an object causes the bomb to explode. A contact fuse would serve the same purpose, how- ever. When an airman sets out to “hook” an enemy craft he soars high into the sky, lets sired+ length, and then looks below him for victims. If he spies enemy aeroplanes he descends quickly, letting down the bomb until the pro- jecting arms come in contact with the enemy craft. out his bomb to any de-. , pe Statues that Run, Dance and Fight The latest development the funny ani- in moving pictures is mated clay figure > Photcs Press Iltus Serv gba motion-picture folk have hit upon another novelty. They callit ‘animated sculp- ture,” which means that they take statues and make them move.. The feat isn’t as difficult as it seems, although the work required is infinitely greater than drawing hundreds of pictures with pen and ink for making an animated cartoon. The figures are first fashioned in clay, then changed to different poses, photographed one by one and projected upon the screen without a break so that they jump about on the screen Mrs. Murphy tells Mrs. Flynn a thing or two in the c aA animated sculpture play, the “Battle of the Suds.”’ Before The three dancing the film will have been completed thousands of Mrs. Even a clay figure chorus girls and Murphys and Mrs. Flynns will have been fashioned to is afraid of an the musicians furnish the action for the most energetic battle royal animated snake. 2 57 258 Popular Science Monthly ; = r The invention consists of three ti jointed arms which tend to fold a together in a straight line because of the action of two sets of oppositely-wound coil springs — placed at the end of one arm and at the joint of the other two. The first set of springs is inclosed in a casing pivoted to a clamp around the stationary steering column, k while the free end of the other two arms is rigidly attached to the rim of, the steering wheel. - | As the wheel is turned from its straight-ahead position, the three arms open out against the action of the coil springs, like lazy tongs. Since the springs are oppositely GENES se : wound, one spring in each set is Miss Dayton’s studio contains countless thousands of wound more tightly than the plastic clay figures. At the right of the sculptress is a other in the turned position. The replica of the old Windsor Hotel depicting the fire pis springs wound to Ge greatest asif they were real. Theeffectisstartingly degree will cause the arms to’ swing realistic and highly amusing. Inoneofthe back and with them the wheel as soon as films only recently completed there are no the hand pressure is removed. less than nine figures, all of them moving ; about as if they were flesh and blood. The rather jerky action serves only to enhance the amusing result. To appreciate the amount of labor re- quired in making these new films it must be remembered that each time one of the sculptured figures moves a new pose must be made. This means, in other words, that the camera must stop until the sculptor goes over each plastic figure and molds it into the correct position before he can photograph it. There are sixteen different poses to a foot of film. Hence for the ordinary reel of one thousand feet there are sixteen thousand separate poses for each figure. Imagine the work required when three or more figures have to be made for each scene! Helena Smith Dayton, of New York city, is the original sculptress with the keen sense of humor and the skilful fingers who makes the figures. yy, ff cramp i FE STEERING \ WHEEL Bringing the Steering Wheel Back to Position Automatically STABILIZER has been patented by means of which the steering wheel of an automobile can be automatically brought back to its normal position after having been turned. The result is that the steering gear directs the vehicle in a straight line As the wheel is turned from its straight-ahead even though the wheel is not gripped. position the three arms open like lazy tongs Fighting the Ocean with a Big Grandstand A great beach esplanade has been erected which will provide much needed protection The bleacher seats, which have a minimum concrete thickness of twelve inches, rest on sand . attacks. overlaid with eighteen inches of solidly packed clay. At the top is a wide promenade tides which have caused so much damage to the wide stretch of sandy beach which is San Francisco’s pride have received a permanent set-back to their destructiveness. A great esplanade, a kind of. glorified grandstand, has been erected which is designed to withstand their On the ocean side the structure consists of five steps, or bleacher seats, anchored in solid rock. The plane of these bleachers is inclined at about twenty-five degrees to the horizontal. Supporting the Tee winter storms and equinoctial bleachers transversely at twenty-foot in- tervals, exeept at the stairways, where they are on ten4oot centers, are H-beams twenty by forty-three inches in section and twenty-seven and one half feet long. From the boulevard or land side the esplanade has the appearance of a massive concrete wall three and one half feet high. The top of the parapet on the ocean side has been made slightly concave, so that as the waves rush up against the wall the water will be thrown back upon itself and will thus lessen the force of the succeeding waves. The entire mass of concrete is tied together with reinforcing iron in such a way that it is practically a solid fortifying wall twenty-five feet in depth and twenty-seven feet wide 259 How the Police Help New Yorkers to Protect Themselves THEATER PROGRAM TEXT BOOK Do You Know? That by street accidents in New York City One person is killed every 14 hours, and One person is injured every 23 minutes You can help to lessen this terrible toll of lives 1, By being careful yourself 2. By teaching others to be careful Statistics show that the majority of accidents are due to carelessness We will enforce the rules for drivers, but Fate must enforce the rules for pedestrians Reckless drivers are fined and imprisoned Reckless walkers are maimed and killed Never cross busy streets except at crossings Never read newspapers while crossing the street Never obstruct your view with your umbrella while crossing the street Always look both ways while crossing, the ‘street Always keep your eyes open and your wits about you Last month 2344 persons were injured in street accidents in New York City Ask your policeman for ‘‘Safety Booklet.” ARTHUR WOODS, Police Commissioner. Do You Know? 1. That by Street Accidents in New Yor' Gity One person is killed every 14 hours and One person is injured every 23 minutes And i. That You May be the Next Person Killed or Injured, Unless You Obey these Rules 1. Never cross the streets except at crossings. Never hitch behind wagons or automobiles. Do not play games in the middle of the street. Pi ecomen Never chase your ball before first seeing that no wagons or automobiles are coming up or down. It is better to save your life than your ball. 5. Always keep your eyes open and your wits about you. : 6. Be careful, and make your friends be careful too. Save their lives as well as your own. 7. Ask your policeman for ‘‘Safety Booklet.’’ ARTHUR WOODS, Police Commissioncre Two kinds of “safety booklets” issued by the New York police to tell the citizen how to protect his life and property. Note that the information is not all of the “don’t” kind Below: Carrying the bundles of booklets from the printers. Fifty thousand posters, three hundred thousand booklets, and. motion picture slides galore have been prepared for the campaign Below: A policeman ‘ente1ing a shop to place a poster in the window. New York shop win- dows are literally plastered with these post- ers of the “help protect yourself’? movement 260 Ore ae ae Help Protect Yourself A great safety movement introduced by the New York police to help the citi- zen to protect his life and property DEPARTMENT | SSUED ; Y OF NEWYORK | NOVEMSER .16_ 1955 WANTED | Everyone in- this house to be a good, | clean American.-citizen. Keep sidewalk | |-and street clean. Put all refuse in the | | Garbage cans and keep the covers on. | ARTHUR WOODS {__________________———} E Americans are the most careless people in the world. We preach the doctrine of safety first in the home, follow it up in the office and shop, and then step out on the street and forget all about it. The result is apparent. Last year twenty- two thousand persons were injured and six hundred and fifty killed by street accidents. That means one person killed every four- teen hours and one injured every twenty- three minutes! A pretty record for a people who started the _ safety-first movement! Confronted with these figures and aware of the fact that they are increasing with alarming rapidity, the police department of New York City, cooperating with the Advertising Club of New York, has started a campaign to impress upon the people of the greater city the absolute necessity of keeping wide awake against dangers that daily confront them. The general purpose of the movement is to help the individual citizen to save his life and property. There are rules for those who walk, rules for those who drive automobiles, precautions against burglars, pickpockets and disease, and instruction on miscellaneous subjects. One of the succinct paragraphs under the heading, ‘““You Who Drive,” is: ‘Your automobile may be under control but how about the other fellow’s?) He may be a crazy man. You don’t know.” Some of the precautions against burglars are: “When you leave your house don’t ad- vertise the fact by pulling down the shades or by leaving a note in the letter-box saying that you will be back at such and such a time. Sneak-thieves profit by such ad- vice. It is an invitation for them to enter. “When your front-door bell rings and you press the button and no one comes to your apartment, notify the janitor immediately. You may have admitted a thief.” In regard to pickpockets you are advised ‘not to be too eager to pull out your watch and give the time of day to everybody who asks you forit. That’s a good opportunity for somebody to grab it and run. Don’t show your money in a public place. It isan invitation to criminals to follow, assault and rob you. Don’t, when shopping, lay your handbag on counters while looking at goods. This is the opportunity for thieves. As for disease, respect your neighbor as much as yourself. Don’t beat your rugs or stir up ashes so that your dirt will be blown into his apartment to fall on his food or be breathed by him. If you are well, keep well by helping others. _ Buy by standard weight or measure, not by basket or prepared package. The po- liceman is your friend. Get his advice. Under miscellaneous information you are asked if you have a good, clear description of your personal property. Could you, if requested, quickly supply a description of each member of-your family? Such de- scriptions are essential if anything serious should happen in your house. Write them in a book. When you see a crime committed, or observe a suspicious person or condition, notify the police at once. The more you cooperate with the police, the more the police can accomplish for you. Regard the policeman as your best friend. ‘You are paying him to keep your street safe and orderly. He is entitled to your help. 262 Popular Science Monthly Finding the exact location of a waterpipe between two buildings by means of a telepipe. The electric current is supplied by four dry batteries. You Can’t See a Pipe Underground, But You Can Hear It HAT is a“‘telepipe?’’ It is an electri- cal device that tells you the location of a buried waterpipe, so that no time is wasted in digging over a large area to find it. The instrument is used for locating conduits, cables, I-beams and_ similar buried objects that are not more than twelve feet below the surface. The photo- graph shows clearly how it is operated. The problem was to find the exact location of the waterpipe between the residence and the factory. This was done by pape: the terminals of the telepipe , to the faucets in front of each building. This done, the opera- tor with his portable outfit, known as the exploring coil, moved slowly over the area known to contain the pipe, listening with the receiver of the instrument to his ear. The hamming tone of the vibrator was his guide. It was heard all through the area enclosed by the pipes in the circuit, except in one spot, which was directly above the buried pipe. The current for the instrument is supplied by four dry batteries, and the entire outfit is easily carried. It weighs about twenty pounds. Its principal advantage lies in the fact that it is very quickly and easily ap- plied and operated, one man being capable of using it alone. When an underground break has occurred and the cellar is in danger of being flooded this feature will be appreciated. The air was supplied to this emergency diver’s helmet through an ordinary automobile pump The humming of the vibrator is the guide Making a Diving Helmet Out of a Kitchen Boiler UT of an ordinary kitchen boiler a Brooklyn engineer has devised a diving helmet. which compares favorably with the expensive diver’s suit. He took one end of a kitchen boiler and notched it to fit the shoulders. Chains were placed on it to give weight, as shown. With this rig and supplied with air by an ordinary duplex automobile pump, he stayed down fifteen minutes at a depth of thirty feet and completed important emergency work. There was no window in this boiler helmet. In a later one, however, an oblong glass paperweight cemented to a hole cut in the front of the helmet served as a window. With this rig and a regular deep- sea pump J. J. Grafflin, who devised the appa- ratus, remained under water nearly two hours at one time. Before Mr. Grafflin hit upon the boiler helmet idea he knock- ed one head from an empty beer keg and made a diving hel- met out of it. To _ steady the keg and overcome its buoy- - ancy when submerged, a man stood on top, holding to a strip of wood that was nailed’ to the keg. With this rough outfit a nearly two minutes at a time. Mr. Grafflin to adopt the kitchen boiler as an efficient diving helmet. Evidently he is a firm believer in the old axiom “‘ Where there’s a will there’s a way.” man was able to stay down | The beer keg led Popular Science Monthly 263 Speaking of Styles—Did You Ever Wear the ‘“‘Mouchoir Teéte’’? EARLY a hundred thousand women and girls over ten years of age in Haiti wear the mouchoir téte or headkerchief. This -is wound around the head bandanna fashion. On Sundays and special occasions the foulard is worn. It is made of silk or of mercerized cotton with brocaded figures woven in it. The tastes of the Haitian women run the whole gamut of colors. Black is a favorite color of the people, but they are fond of solid reds, yellows, oranges and purples. The principal defect of the colors is that they are not fast colors. A headkerchief and a heavy rain make a sorry sent of any woman in Haiti. Practically the entire supply of : nes headkerchiefs has come from Europe We have it now—the soda water fountain in a railway car. rar many years The Ricachester Henceforth ice cream sodas will lighten our journeys district supplies the bulk of the cottons, while the others come from Belfast. The Traveler’s Soda Fountain Is an Adjunct to the Dining Car MERICAN fondness for soda water has led to the €stablishment of soda fountains in many foreign places frequented ENICE, California, has a street sign by American travelers. Cities as wide apart _ with possibilities. It marks the as Paris and Havana have set up soda corner of Swan Avenue. Instead of fountains to assuage the national thirst ol carrying the regulation lettering, it is the American sojourning within ' A California Novelty in Street Signs shaped like the bird from which the their gates. avenue takes its name and is painted white. If this idea were ex- tended to other cities we would see a general en- livening of our corners. There would be portrait galleries for such streets as Washington, Madison, Adams, and the like, while symbols could be found readily enough for Cherry, Pearl and Wall Streets. Municipal Art Commissions might pass upon the sign painter's work so that the cherry would not be mistaken for an apple or the swan for a goose. After viewing the cam- paign portraits, it is just as well, perhaps, that the project has not been seriously considered. It would not require a very great knowledge of English to read the name of this avenue But here in the United States no effort was made to satisfy the cravings of the traveler temporarily separated from his—or should it be her?—favorite nut sundae dispenser. A short time ago a clever railroad man, whose first thought is always for the comfort of his passengers, was won- dering what his road could do to make its guests forget the tedium of travel. “I have it,’”’ he exclaimed, “‘a soda foun- tain!’”’ So now when you a-journeying go, you may find yourself in a car in the end of which is a reg- ular soda fountain capable of supplying all sorts of sweet concoctions and soft drinks. The Most Wondertul of Worlds — Myriads of small particles revolve in rings around “Saturn, a giant planet which has ten moons and which is so light that it would float in water N the entire visible universe, there is © no body so mysterious, so beautiful as Saturn and his marvelous system of rings and planets. But the splendor of Saturn was revealed only to modern times. He became ‘magnificent only after the telescope was invented; for to the naked eye, he appears only as a first magnitude star, revealing nothing of his strange appendages. It was not only the lack of instruments that withheld the beauty of Saturn from the ancients, but his remoteness as well. The average distance of Saturn from the Sun is about 886,000,000 miles. That enormous orbit around the Sun is traveled in the space of twenty-nine and a half years. In other words, a year on Saturn is the equivalent of twenty-nine and a halt of our years. But his day is only ten hours jourteen minutes long. It must not be sup- posed from this that Saturn is slow. Ina single second he covers nearly six miles—a speed far greater than that of a rifle bullet. Saturn Would Float on Water Although Saturn is enormously larger than the Earth, he is not nearly so dense. If it were possible to drop Saturn into an inconceivably vast ocean, he would float like so much pine- wood. And yet, so enormous is’ the “bulk of Saturn (his diameter at the equator is, 75,000 miles) that he weighs more than ninety- -five times as.much as the Earth... ~ A. dense cloak of clouds envelopes Saturn constantly.’ What is behind that cloak? Noone knows. After an exhaustive study the late Professor Percival Lowell concluded that Saturn’s interior was layered like an onion. - These various layers rotate at different speeds. The first man who ever made a study of Saturn through a telescope, first because he invented the telescope, was Galileo. He could hardly believe his eyes when he saw the planet through his feeble instru- ment. He beheld the ring on edge. As the years went by, what seemed at first two thin arms extending out from each side of the planet, opened. Once in every fifteen years ic ring is so tilted +lbe cf appears like a mere line. to wait seven and a half years before the ring changed in appearance.” He did not _know that he was looking at a true ring— — so startlingly novel was the aenee Sig was simply puzzled. It remained for Huyghines to announce — that ‘“‘the planet is surrounded by a slender ~ flat ring everywhere distinct from its — surface.’’ And he was the first astronomer to predict the dates for the vanishing and reappearing of the ring. The Marvelous Rings are T housands. of Miles Broad The single ring which the older ob e1 ve studied has been resolved by modern” aie power instruments 4nto three rind oat outer bright ring, an inner bright ring and © a dark ring. The dark ring is called the © crape ring, because it suggests a veil i in texture. The dimensions of the various rings are given on our drawing by Mr. Scriven Bolton (reproduced from thé Illustrated’ London News and added to by the PopULAR SCIENCE MONTHLY) and are those estab- lished by Professor Barnard of Yerkes Observatory. Itis altogether probable that if we had more powerful instruments than those at present at our disposal, we would be able to resolve these three rings into still, others. Sir Robert Ball has thus vividly pictured the appearance of ringed Saturn: . “Tmagine that you stood on the- planet’ Satur) near his equator; over your head stretches the ri which sinks down to the horizon in the east and in the west. The half ring above your horizon would then resemble a mighty arch, with a span of a hundred thousand miles. Every particle of this arch is drawn toward Saturn by gravitation, and if the arch continues to exist, it must do so in obedience to the ordinary mechanical laws which regulate the railway arches with which we are familiar. “The continuance of these arches depends upon the resistance of the stones forming them to a crushing force. Each stone of an arch is subjected to a vast pressure, but stone is a material capable of ‘resisting such pressure, and the arch remains. The wider the span of the arch, the greater is the pressure to which each stone is exposed. At length -So Galileo’ had Saturn—A Magnificent Ringed World CRAPE RING 10,608 MILES BROAD INNER BRIGHT RING 19.189 MILES BROAD I COMPARATIVE SIZE OF THE EARTH From a drawing by Scriven Bolton in the Illustrated London News, with additions by Poputar ScrENCE MONTHLY Here we have the most wonderful creation of the visible universe—Saturn and his rings of flying myriads of small particles, attended by his eight largest satellites. Saturn is nine times greater in diameter than the earth. Through a telescope we discern simply a vaporous atmosphere, tor- mented by an intensely heated core forever hidden from our gaze. Cloud vapor is incessantly shot vertically into the upper atmosphere layers by internal convulsions. The rings are com- posed of nothing more than a flight of myriads of small particles around their primary, the inner ones revolving in five hours. Each particle, therefore, is a tiny moon 266 the span is reached which corresponds to a pressure as great as the stones can safely bear, and accord- ingly we thus find the limiting span over which a single arch of masonry can be extended. Apply these principles to the stupendous arch formed by the ring of Saturn. It can be shown that the pressure on the materials of the arch capable of spanning an abyss of such awful magnitude would be something so enormous that no materials we know of would be capable of bearing it. ring formed of the toughest steel that was ever made, the pressure would be so great that the metal would be squeezed like liquid and the light structure would collapse and fall down on the surface of the planet.” What materials can sustain a stress so stupendous? We must look not for ma- terials, but for force which opposes the attraction of Saturn. This force is the so-called centrifugal force. Sir Robert Ball says: ‘‘If we imagine the ring to rotate, the centrifugal force at all points is in an op- posite direction to the attractive force, and hence the enormous stress on the ring can be abated and one difficulty can be over come.” What are the Strange Rings? Mathematicians have studied this prob- lem of Saturn’s rings. It is one of the most difficult, most fascinating in all astronomic- al science. And what is the conclusion of the mathematicians? Simply that each ring is an enormous shoal of extremely minute bodies. “Each of these little . bodies pursues an orbit of its own around the planet and is infact merely asatellite. These bodies are so numerous and so close to- gether that Were the’ Popular Science Monthly right in thus conceiving the structure of Saturn’s rings. Ten Moons Revolve Around Saturn — Saturn has ten moons. The largest of these is Zitan which has a diameter of 2,484 miles. Their names in the order in which they are to be found outwardly from the planet are Mimas, Enzeladus, Tethys, Dione, Thea, Titan, Themis, Hyperion, Japetus and Phoebe. Two of the moons are so small that they cannot be seen through the telescope at all. Only on the photographic plate are they visible. Our cover picture, based on a drawing ~ by Morell, the astronomical artist, shows the wonderiul ring system as it would appear in the most powerful telescopes. ten moons from which this view could be obtained. The other satellites keep strictly to the plane of the ring. Japetus itself{— which is apparently the size of our moon but is. ten times farther from the parent body—is remarkable for the variability of its light, which suggests the presence of an atmosphere and the formation of clouds. Proctor and other astronomers even be- lieved that it might be the abode of living creatures, but that view is not shared by astronomers of our time. Floating a River Caisson Into Position for Sinking RY caissons which act as bridge or pier supports are usually built either on the they seem to us to be. continu- ous, and they may be ‘very minute —per- haps not larger than the glob- ules of. water found in an or- dinary «cloud above the sur- face of. the earth, which even at a short distance, seems like a continu- ous body.”’ In- struments have been devised which show and skidded or launched into the river, or else they are built on a pontoon, made of two or more parts bolted together, as the accom- panying photo- graph shows. son has been placed in the correct position for sinking, the - pontoon. is: un- bolted and flood- ed, which allows the caisson to that the mathe- maticians are Caissons built on a pontoon on which they are car- ried to the desired location and floated into position float into posi- tion. — For the. sake of effect, he has, as it were, taken his - stand upon Japetus, the only one of Saturn’s_ shore | When the cais-— Popular Science Monthly The City Alligator. He Cleans oa 3 the Sewers of Fort Meade, Florida HE alligator has gradu- @ ated into the useful class. At last his sluggish energy has been -usefully directed. Recently a six-hundred- foot, twelve-inch sewer pipe in Fort Meade, Florida, be- came clogged with sand and dirt. According to the “Engineering Record”’ several Fark ae sewer-cleaning contrivances were used and about $1,500 was spent, but to no avail. The pipe remained clogged as before. At this juncture the superintendent of water and sewers secured a small alli- gator, to which he fastened a rope. The *gator was lowered into the pipe. After a struggle in the unsavory environment he reached the next manhole, dragging the rope after him. When he had traveled one section of the pipe, the rope, to the middle of which knotted chains were attached, was pulled back and forth and the obstructions removed. Following this success, other alliga- tors were .used, until at the present The blotched and wrinkled hide of a living, squirming alligator makes a most efficient sewer-cleaning apparatus a complete grocery store on wheels. The vehicle serves a large rural territory where the homes of the farmers are at considerable distance from the town store. It makes more than a hundred stops per day serving its customers with a complete stock of groceries, green goods, meats and candies. The interior of the store is electrically lighted and heated from the exhaust gases of the motor in winter time. Beneath the body at the rear are two chicken coops with hinged swing-back bottoms for live poultry. - time ten are employed for cleaning sewers. They are doing what skilled workmen equipped with modern appa- ratus have failed to do. Grocery Store on Wheels Serves Large Rural Territories HE progressive merchandizing me- 4 thods of to-day made possible by the proper utilization of the motor truck are well illustrated in the two accompanying views which picture Se NN ER SSS = a =e The interior of the grocery car with its snow-white bins and spotless counters Our new battleships are the most daring ever proposed. They will have a length of 850 feet ; The Swiftest and Biggest The power plant which drives New York’s subway trains develops 65,000 horsepower —less than 40% of that required to driveour Sn ae ee ene OE DT ee between perpendiculars and an over-all length of 874 feet. What that means is shown by the FEW months ago the United States Navy Department announced that it would build battle cruisers with a length of 850 feet and a speed of thirty-five _ knots—forty miles an hour. Only ship- builders and naval officers realized the full meaning of the Department’s program. England is said to have completed battle- ships of about the same size but never have we attempted to build a fighting vessel so huge. The battles fought by the British and German fleets in the North Sea were object lessons. They showed that sea fights are won by speed and hitting power. And so the Navy Department determined to build the fastest battle-cruisers and to arm them with the most powerful guns. What is a battle cruiser? It is a ship which is faster than a superdreadnought, — but not so heavily armored. Battle cruisers , were lost in the last North Sea battle largely because they had not the protection of a superdreadnought.. But although they went down, they saved the day for England. — They kept the German fleet in action, until the British Grand Fleet with its super- .— dreadnoughts could appear on the scene. must have. ‘ It is one thing to design a battle cruiser 850 feet long with a speed of thirty-five knots; quite another to build it. It would seem simple enough to magnify existing models and to put in bigger engines. That LLY. PUBLIC LIBRARY BUILDING SH ee 7 Or aca ey om & ® —|-, 00/ ——s| 5 i . Be Meare Bd ED Comparison between the proposed cruiser and New York city streets. These cruisers will have ten fourteen-inch, twenty five-inch and four three-inch anti-air-craft guns besides eight torpedo-tubes 968 a = 4 And so we decide that battle cruisers we ; Seer a a = Ei ee al hell Battle Cruisers in the World proposed battle cruisers at a speed of 35 knots. Never in our naval history has such a power plant been installed in a ship parison with ; picture. They will cost $16,500,000 each. It will take 180,000 horsepower to drive one at 35 knots _ 70,000 horsepower. engines. is not the way ships are built. The Lusitania made twenty-five knots with To make fifty knots, it might be supposed that it would be necessary merely to double the size of the Battle cruiser building’ would be _ easy if that were all. Each additional knot is purchased at the expenditure of thou- _ sands of horsepower. Our naval engineers _ estimate that 180,000 horsepower will be _ required to develop thirty-five knots in one of the new battle cruisers. is a ae Never have marine engines of that power been built. As a result, American shipbuilding companies are loath to bid on the cruisers. The builders say that they will not bid ex- cept with the understanding that they will _ receive the cost of building plus ten percent. A similar plan of paying for ships was worked out in Germany when the giants Imperator and Vaterland were built. The Naval Appropriation Act of Aug. 29, 1916, _ permits this method of bidding. Our _shipbuilders maintain that even on the _ ten-percent-plus-cost basis they will prob- ably be losers because the Government will _ undoubtedly copy their successful models, _and build ships in its own yards after the _hard work has been done in private yards. To develop a speed of: thirty-five } knots—forty miles—an hour, turbines must _be employed. A steam turbine works on the windmill principle. Steam spurts against blades on a long shaft. The old- fashioned steam engine—“‘reciprocating en- gine” in engineers’ language—is very tall. Its pistons work up and down in the cylinders, as everyone knows. Recipro- cating engines take up much space, so much, in fact, that a ship like the Lusitania, which was driven by them, was practically all engines. The steam turbine requires very little head room and very little floor space, so that great economies can thus be effected. Moreover, oil will be used as fuel, which can be carried in the double bottom of the cruiser, thus further releasing space which would otherwise have to be taken up by coal bunkers. Moreover, steam turbines are lighter than recipro- cating engines. They can be heavily overloaded, should emergency arise. On the other hand, the use of steam turbines is not all plain sailing; for turbire engines, unlike reciprocating engines, aré non-reversible and special means must be provided for backing. Furthermore, the most éfficient speed of revolution of a boat’s propeller is very-much lower than the most efficient speed of the shaft of a turbine engine. Therefore it is not the most efficient proceeding to couple the turbine directly to the propeller-shaft. Gearing and a novel method of driving 269 270 electrically with turbine engines will prob- ably be employed on the new vessels. The British battleship Queen Elizabeth, which took a prominent part in the Dardanelles campaign, has a rating of 60,000 horsepower and is a _ twenty-five- knot vessel. The British Tiger was designed for a speed of 28 knots with a rating of 100,000 horsepower. The German battleship Goeben, which made her famous dash for Turkey at the beginning of the war, is a twenty-eight-knot vessel of 70,000 horsepower, while among the later vessels the Seydlitz might be mentioned as a twenty-nine knot, 100,000 horsepower vessel. Fhe Vaterland, most impressive of the German steamers now resting in New York harbor, has a horsepower rating of 65,000 and a speed of twenty-four knots. The great Waterside station of the New York Edison Co., located on the East River, is reputed to be the largest steam plant in the world. Two buildings comprise this station. No. 1, the original station, has a total capa- city of about 165,- ooo horsepower, which is con- siderably less than the power of one of the new battle cruisers. The two buildings of the Waterside plant develop about 288,000 horsepower, which is about 60 per cent more power than one of the new battle cruisers will develop. The great 59th Street plant of the Interborough Rapid Transit Co., which supplies power for the trains of New York’s subway, develops only a little over 65,000 horsépower—less than forty per cent of that of the proposed battle cruiser. In 1900 the total hydro-electric power developed in the United States was little more than enough to run one of the new battle cruisers, amounting to about 200,000 horsepower. To-day the total horsepower developed hydro- electrically in this country would run about ten of the battle cruisers. The greatest hydro-electric develop- ment of all, that at Niagara Falls, is perhaps the most impressive ‘subject of all for comparative purposes. The The motorcycle has many necessary accessories to carry so that a combination ‘lamp and horn arrange- ment fastened to the handlebar saves valuable space LAMP BULB PERFORATIONS Popular Science Monthly and the fall is 160 feet. The power houses planned for both American and Canadian sides of the Falls, including those in opera- tion, are expected to utilize twenty-one and a half per cent of the mean flow of the — river, utilizing a total of 650,000 horse- power. This vast amount of power would — be insufficient to run even four of our new battle cruisers. ‘7 Turning Your Motorcycle Lamp into. a : 4 Horn Without Changing Its Shape — 5 a COMBINED lamp and _horr a ch? o Nathaniel B. Wales of. Boe He combines in a single u Slectroaceae of the. producer are mounted in a rear extension .of the lam = = case without changing its size — _ or shape. Immediately in — front of the sound pro- ducer is the electric _ light bulb. Fora — megaphone or sound chamber — to intensify the © volume of sound — the inventor utilizes the hood, which fre- quently serves on gas lamps for the escape of heat. In other words, the wall adjacent to the parabolic reflector — becomes the sound chamber. Obviously, it _ is not necessary to change the size of the, lamp to do this. If this does not insu a sufficient volume of sound the circular front of the lens case may be utilized. aaah HANDLE BAR mean flow of the Niagara River is about 222,000 cubic feet per second The sound-box of the horn is placed in the rear extension of the lamp case. The hood acts as a megaphone to intensify the volume of sound Is Space All AglowP The new startling theory advanced by Professor Barnard to explain non-luminous bodies brought out in relief against the sky The photograph on the left is a luminous neb- ula whichis a mass of gas. But what is the curious irregular hole among the stars in the photograph on the right? These black holes are supposed to be openings in the rich regions of the stars. Professor Barnard is inclined to the belief that the supposed holes are feebly luminous bodies, and that they were once bright like the nebula shown at the left, but have lost their light and become blackened with age sideration of the dark spots in the sky. Professor Barnard of the Yerkes Observatory has been studying this side of the question lately, and the results that he has already obtained lead him to speculations that are both new and interest- ing. The nebulae of the sky have generally been considered to be intensely hot. These huge masses of luminous gas would cool and contract until, after millions of years, the more compact stars were formed. The stars might cool further until no light could be seen coming from them; but it was not generally believed that the gases of the nebulae themselves could cool and still remain in the gaseous state. One of the first results of Professor Barnard’s work, however, was to lead him to believe differently. Let us follow him through his reasoning. He says that in photographing the sky, large dark markings have often been noticed in the photographs. At first blush they seem merely huge openings in the rich region of stars through which one looks out into the blackness of the space beyond. Although there are undoubtedly such va- cancies, the more one becomes familiar with others of them, the less this explana- tion appeals. _ To suggest the true explanation, Profes- sor Barnard has prepared the pair of photo- graphs appearing on this page. These, he a eee is coming to the front the con- explains, have been made exactly to the same scale, and a striking resemblance is seen between the two objects that stand out in them. But one is an ordinary luminous nebula, and the other is a dark— what? His observations induce him to believe that it, too, is a nebula, but one in which the great mass of gas has finally cooled and lost its light. The gas of the nebula, like many others that Professor Barnard has studied, is still dense enough to take definite outline and to stand out against the luminous background behind. But right at this point we would be led to still another conclusion. There are dark spots having very definite outlines to be seen in the heavens, where, there is every evidence to believe, there are neither luminous stars nor luminous nebulae to light up a background for them. What then, is the cause for the luminous back- ground in such cases? There seems to be but one possible explanation, and that is that space itself is luminous. Space itself might be filled with the feeblest luminosity, so feeble, indeed, that at the tremendous distances to the fixed stars it is not even perceptible to sight. Then, as space is sup- posed to be of infinite extent,this luminosity will increase in apparent density until, finally, it would become dense enough to affect a sensitive photographic plate. Only in this way would it be possible to explain how non-luminous objects could be brought out in relief in these parts of the sky. 271 _ Popular Science Monthly By pressing the foot-lever the door opens. By the use of branched rods under the car both doors may be opened at once Automobile Doors May Be Opened from the Driver’s Seat EMAINING in his seat, the driver of any two-seated automobile may un- lock and open the rear or tonneau doors with his foot, provided the doors are fitted with the simple device shown in the accompanying illus- tration. This consists of a bevel-ended snap bolt holding each door closed by means of a coil spring, the rear end of the bolt having a pin working in a slot in a downwardly- curved bar positioned in a curved recess between the inside and outside: of the door. The rear end of the bar is connected with the rear end of a long rod beneath the car body and bent up through a slot in the floor. The forward end of this rod is attached. to the lower end of a lever pivoted to the floor of the driver's cab, the upper end car- rying a_ pedal. A dash-pot preferably of the pneumatic type, is carried ahead of the lever and connected with its lower extremity. A push on the pedal causes the rod under A—Latch. B—Barrel. - The thumb operates the trigger C—Trigger. the car to be moved toward the rear and with it the curved bar and the snap bolt, thus unlock- ing the door. When the pressure on the pedal is released, the dash-pot on the pedal lever forces the door to close and lock automatically. One device can be used to open either side door alone or both doors simultaneously. Each door is provided with a knob on the snap bolt to open it from the rear seat independently of the foot operated device. Shoot the Robber with Your Pen-Knife Revolver POCKET knife which has two blades and an attachment that enables it to discharge a twenty-two caliber short cart- ridge, either blank or ball, is one of the latest novel- ties to be placed on the market. It is said to be practically as effective as a regular twenty-two cal- iber revolver of. the short barrel type. It is three inches long and one-half 1- inch wide. You hold the revolver in your right hand with the back edge up. You pull back a little latch on the back of the knife, and at the same time the barrel ‘is tilted forward and opened with the left forefinger. Then you in- sert the cartridge and latch the barrel securely. The trigger is placed on the side of the knife in a raised position, ready for firing. You hold the knife in your right hand with the end of the right thumb on top of the trigger. Press the trigger down quickly and the cartridge is exploded. It is aimed in the same Way as any ordinary revolver. 1 aT ares ft) ee eee OT ee Will We Dress in Paper Clothes? They make socks, chairs and twine out of paper now, and you can’t tell the difference between them and the usual product N the good old days of plenty, how lav- ishly we used that imposing natural resource of ours, the great American forests. We cut down tree after tree without taking the slightest measures for replanting them. When we floated the trees to our saw mills we cut one-third of them into lumber and we threw the rest away. But finally, when we could not help but see that our forests were nearing depletion, we estab- lished the Forest Serv- ice to determine what could be done! And ever since that time we have learned a host of amaz- ing things about lum- ber and the uses of lum- ber waste. But who would have expected as a result that some day we would be mak- ing such things as arti- ficial silks from such materials as sawdust? Yet that is exactly what is being done. Lumber waste that was once considered worthless is STA = SSY These interesting articles w from wood pulp. a VI roan ere all made They represent all varieties and grades of paper “silk” A comfortable couch for the veranda or the summer cottage. It is made from spun paper reeds woven over a rattan It is as durable as it is attractive and wood frame. 273 now mixed with small quantities of wood pulp, made into paper, some- times mixed with cotton or woolen fleece, and then spun into “silk” neckties and “‘silk’’ socks. And, as the ac- companying photo- graphs amply show, these are not the only commodities that are being so made with suc- cess. It is already a matter of economy to manufacture articles from spun paper which range in diversity from furniture and rugs to suitcases and flour bags. Equally as interest- ing is she manner in which the paper is spun into twine and into thread. In a process for making twine, the paper is first cut into long strips about one inch wide. These strips are then passed through a machine which corru- gates them in the direc- tion of their lengths. These are then twisted by hand into the shape of twine, as the illus- tration shows. The twine is finally reduced to the proper diameter by feeding it into other machines which wind the thread up very tightly. this kind is used for making the larger size twines and ropes, and for heavy cables for towing ships. For spinning the fine twines that are used for wrapping bun- dles and for binding harvested grain, a slightly different method is used. paper are wound up in the form of a disk. The inner edge of the paper disk is then pulled out, and A process of Narrow strips of the Q74 Popular Science Monthly _ FORMING CORRUGATED STRIP OF PAPER INTO TWINE The paper strip is corrugated in uniform lines and is then grasped firmly and twisted into a string the elongated helix so formed is further hand-twisted into a very thin tube. This — tube is then further collapsed and twisted . until a strong tightly-wound string i is ob- tained. Thus, the first For making the thread that is \ used in clothing, another prelimi- ; nary process must be used. In us, a wide sheet of moistened wood pulp is fed into a compression-roller under another sheet of either cotton or woolen fleece of the same width. Both sheets are quite soft, so that after they have been forced through the heavy rollers, they will come out with their fibers interen- gaged and in the form of one solid web. The duplex web so formed is then placed in a cutting ma- chine and divided into long narrow strips. These may then be hand-twisted and spun in.a manner similar to that used in making the finer twines described above. The finished thread is then woven into cloth in any of the ways in which ordinary thread is woven. But because of its PAPER PULP , FEEDER ROLLED PAPER IN FORM OF DISK COLLAPSED AND 0 Method of strengthening paper twine having a fibrous core. The paper rib- bon is first curled around the core FLEECE THREAD DUPLEX WEB AVELING SCREEN te Rolling the pulp to compress it into a duplex web, which is the first stage in the preparation of the paper strips tion. TWISTING CUT STRIPS INTO X CUTTING WES INTO STRIPS _ Cutting the web into long narrow strips ~ after it has been compressed into duplex io preparatory to twisting different iene. the cloth thats is ‘made from spun paper may be _beneficently treated in ways which can not be used with the ordinary cotton or woolen cloths. treatment consists in im- mersing the paper-spun. cloth in great vats contain- ing solutions of emulsions | of fat. The cloth will grad- ually absorb the grease until it has become weil saturated with it. The re- sult is that the cloth is made: water-proof and its former stiffness is removed. The cloth is then still further improved by treat- ing it in antiseptic solu- tions. These will make the cloth both air-tight and sanitary. Being now both ‘moisture and air- proof, the cloth is ex- ceedingly warm since the radiation of the heat from the body is pre- vented by this treatment to a very large. extent. By processes which are based upon the ones that cae “SECTION OF TwISTEC THREAD COMPLETED THREAD This thread has a surrounding covering of fleece securely united to the paper por- It is twisted into a felt-like fabric " - Popular Science Monthly 275 Samples of spun paper cord and rope. Package twine of Swedish make. (Swedish). 8. Same as No. 1. have just been described, a host of other woven materials that are made from paper thread are being successfully manufac- tured. These include such important com- modities as artificial linens and leathers. Traveling-bags and suitcases made from artificial leather are now selling for five and six dollars apiece. Other types of matting which are made by similar processes but which employ different mixtures of paper thread, serve a diversity of uses. Thus paper mattings are taking the place of burlap wallpapers; they are serving as backing for linoleums and oilcloths, and 3. Same as No. 1, medium weight. 5. Variegated skipping rope. 6. Horse blanket . webbing. 9. Heavy package twine. 1. Single strand package twine of American make. 2. 4. Cable clothesline 7. Three-strand rope. 10. Single strand package twine (Swedish). they are being used in great quantities in the making of fancy paper novelties. And these facts become all the more amaz- ing when we consider that the entire spun- paper industry is but a few years old. By far the most astonishing progress, however, has been made in the substitution of spun paper for expensive cotton and flax in the making of artificial linen. The United States is not alone in this, however. Germany and Austria are now using spun paper far more extensively than are we; in fact, their use of it has enabled them to solve many of their war problems. .," « - ~~ MeL, wae }.veeees j ji ; f ) f 5 | a jal Peary NEE a Le ee ' ; peearresteties threes) peseerecernr nates presi ety %. CESS es) SReS Sete S es > : as ~~ e's eee SS FSS ee ee ae es eS ee ee ee A. Heavy closely woven three-strand paper burlap used for bagsand bagging. B. A single-strand, open-weave paper onion bag, reinforced and edged with paper pulp and sewed with cotton How Much intelligent The measuring stick is a yard long and has two scales on it, one in inches and the other in ratios of from one- eighth to fourteen and three-fourths yards Deck That Cloth Cost? As the clerk measures off the goods this measuring stick registers the cost of each yard and a fraction of a yard yard cost as is desired. In this respect the four sheets are exactly alike. They differ in the figures along the bottom of the sheet which represent yards in fractions of quarters. takes up a space along the ratio scale of two and three-quarter yards. The next sheet or roll =~ takes up from three to six and three-quarter yards; the one next that from ,seven to ten 10 yds. at 14cts. = $1.40 and three- ane fl ee me ——— G —= ——— Paaa aenT wee ny tw dan ae —= H ; ‘ H SHE E Bigislaies| | ‘ } | | From 3 to 634 yds. long ' ae aire arate gia | ; ; ; ‘ This roll gives | |.__...-- a ea ear = | Ne This roll - ' f good ‘1 1 1 Lt # # 3 # 3 % : a ad . ; cost of goods ; tee cas BREE sae | from 11 to 1 : from 0 to 234 \ ; \ 1484 yds. long ‘a 1 yds. long ’ 7 to 10% yds. is ; : : ~ 1 ‘ LS Af s) - 5 eliminate losses made by store clerks in Over measuring and in calculating the cost of fractional yards. It consists of two main parts—a measuring stick attached to the edge of the counter and a series of four rolls of paper with sets of figures on them. These rolls of paper are spring-operated. The measuring stick is just one yard long. It has two scales on it. That nearest _the edge of the counter is in inches, running from zero to thirty-six inches or one yard. The other scale is laid off on the edge of the stick farthest away from the counter edge. It takes up almost thirty-six inches, but it is laid off to a certain scale or ratio to repre- sent from one-eighth to fourteen and three-_ quarter yards. This scale is divided into four equal parts as indicated by the arrows. One of the rolls of paper mentioned is fitted between each of the arrows. Each roll surface is divided off into a series of rectangles with figures in each. The figures in the left and right border rectangles of each sheet or roll represent the cost of the goods in’ cents, beginning with two cents and going up to as high a A MACHINE has been designed to quarter yards and the one on the extreme right from eleven to fourteen and three-quarter yards. . The figures along the bottom of each sheet correspond with the yardage of the ratio scale. The figures in the rectangles, between the side and bottom figures, represent the cost of the goods in dollars and cents. Each cost figure is the multiplication of the bottom figure by that of the cost per yard on the same level line as the final cost. The clerk measures off the goods a yard atatime. If the purchase is ten yards, the third roll is pulled out from the left. If the goods costs fourteen cents a yard, the figure fourteen is found in the left-hand border column, reading across to the right until the clerk comes to the vertical column with the figure 10 at the bottom. Then the cost is found to be $1.40. Other frac- tional yards and fractional cents purchases are found in the same easy manner. There are stops at each end of the meas- uring stick to prevent the clerk from meas- uring more than a yard ata time. The rolls of paper pull out and roll up again like ordinary roller shades. 976 The sheet to the extreme left. Pee ee B ee eT a ee oe oe es TS a ’ J : q . 4 : ‘ = af ; 7 _ . APPLICANTS for _posi- Could You Pass This Examination P It is the one given by a street railway company to applicants for the positions of motormen and conductors. It is harder than it seems at a casual glance . tions on the Dallas " street railways are sci- entifically selected. The pur- pose is to secure the quick- | te does. est thinkers and those most capable of obeying orders. According to P. W. Ger- hardt, superintendent of transportation, the question of accident prevention rests with the man on the car. Fool-proof equipment, safety first campaigns, lectures, con- tests and prizes all do their _ part toward the reduction of accidents, but, according to three crosses between these two names of boys: George.........- Henry. Notice these two unmbers,3,5. “+ if iron is heavier than water, write the larger number here... .. But if iron is lighter, write the smaller Mr. Gerhardt, it is the man .:+-. Show by a cross when the nights are longer: In summer?......in winter?..... Give the correct Pra NO NAG gy ok cen gar chtpaccd tho Lt acmettoe, Vet wre the best dter of your ret really counts. name and last letter of your last name at the ends of this li Prospective employees are | 3. Add the following as indicated: : . 63429 34321 76005 57333 62491 78845 10001 27345 given three tests, respective- | jo507 19358 19008 58888 66647 10002 99009 15493 ly, attention test, observa- | — — ee = — oa ome ae, tion test and judgment test. | 4 Subtract the following as indicated: : : 98563 56321 98765 76543 79989 80001 90990 76598 In the accompanying illus- | se. 10057 56789 56539 78890 71000 10009 35873 tration the printed question blank used in the attention testisshown. Questionsone | *S axa and two are in the way of | catch questions and require the closest attention of the applicant. Questions three, Two th GENERAL DIRECTIONS: Deo what the printed instructions tell you to do. Do not ask the examiner any questions about the examination. Do not ask any other person who is taking the examination any questior or watch any one to see what Work as rapidly as you can WITHOUT MAKING ANY MISTAKES. 1. Write your name and permanent address here. 2. Do what it says te do as quickly as you can, but be careful to notice just what it does say. With your pencil make a dot over any one of these letters, F G H I J, and a cross after the longest of these three words: BOY, MOTHER, GIRL. Then, if Christmas comes in March, make a cross right here oa but if not, pass along to the next question and tell where the sun rises. ....If you believe Edison dis- cept G in this space... -.- make two crosses here... . ; but if not, make a circle here. ... .or else a square here. .... Be sure to make 5. Multiply the following as indicated: 6. Set down and add the following: Five hundred and fifty-three dollars and five cents. One hundred and ninety-nine dollars and four cents, Two thousand and three dollars. - ATTENTION TEST ~ 93976 53002 41999 59117 41009 35873 17 5 8 a d seven hundred and forty dollars and ninety-one cents. four, five and six are arith- metical questions. The ap- plicant is timed with a stop watch to determine how long he takes to answer the questions, and the number of omissions and errors are counted. The test is given but once, as its effectiveness depends wholly upon its novelty. The object is to determine the applicant’s ability to receive instructions, and to do as he is told todo. ~ But long before the applicant comes to the attention test he is put through other tests he does not know about. Says Mr. Gerhardt: “All applicants are eliminated who are in any wise crippled, or deformed, or who are repulsive in appearance, dirty or sloven- ly in their dress, or who show signs of ex- cessive use of tobacco or liquor. We cannot afford to place on our cars any man whose Test blank used in determining the eligibility of an applicant, and his ability to do exactly as he is told without hesitancy personal appearance may be repulsive to our passengers, nor can we afford to risk. hiring a man who is a slave of the cigarette, or who needs the stimulus of alcohol to carry him through the ordeal of making application for employment. “We further eliminate all applicants under twenty-one years of age or over forty years. The work on the street car is a man’s job, and cannot be intrusted to a boy, nor can we hope to secure the best results from a man who has lost his spring of youth and is passing into the summer of middle age.” Many scientific appraisers of employees lay great stress on the applicant’s walk. Much can be inferred from it, they say, as to habits of thought and conduct. Q77 The Inventor Invades the Workshop and the Office A file handle with an elas- a — tic ferrule. A Wes spring holds i BS 4 the filetang in % A dustless disk grinder with an ad- an elastic grip An air-operated arbor press; the justment for accurately grinding downward or pressing stroke is segment ends or any angular face slow, the upward stroke fast At left: An internal cylinder grinding machine in..which the work-holding table can be tilted to any angle. A vertical bar with a circular rack is fed around and down at the ‘same time by the horizontal motor operating on gearing. Inside . the main bar isa sleeve containing a grinding spindle Creasing your trousers while you wear them. The pressing board is held in one hand and two revolving iron drums are operated by the other 1 Oy i 19443 A street-car snow scraper with ad- A drill press, vise, pipe vise and anvil all in one. justable blades resting in rail flanges. A hollow screw holds a drill which may be revolved It is operated by air or by a lever by handles. A steady wooden base is provided 278 a ae Se And Here Is the Result i Above: Testing the strength of screwdrivers. The point is placed in a socket and turned with a wrench while the dial on the scale registers exactly the stress exerted At right above: A spring lock-nut con- sists of a punching of spring steel bent double and tempered. The punching is so shaped that when fin- ished the outline is that of a standard nut Below: A barrel chair. The seat and back are made of two-inch slats. The arm rests are wide cending flanged steps Above: A new car bumper consists of a series of as- in New Mechanical Kinks ae | Above: A safety planer guard. A shutter sur- rounds the knife between cuts and an aluminum guard covers the unused part of the knife when the stock is being fed to it At left: A con- venient check-sorter with a capacity of fourteen hundred checks. When the checks are in place the front place is auto- matically locked so that there is no danger of losing the contents Below: An automatic cut-out transformer for use with small currents, as for toys 280 A long: pin jabbed into the cigar holds the appliance and serves as a shaft on which the disk slides Ensnaring the Ashes of a Cigar as You Smoke OU need not let the ashes of-a cigar get away from you. A new appliance has been devised for catching them and for holding them safely. You need only to turn a cigar which has this appliance until its butt-end faces upwards and then until its butt-end faces downwards and the cigar is decapitated of ashes, which are caught in a small receptacle. The mystery is easily explained. A long pin, jabbed into the cigar, serves the double purpose of holding the appliance on and of providing a shaft on which the receptacle may slide. But this is not an ordinary receptacle. It is divided into two parts by a metal partition having asmall opening. In the half nearer to the cigar is a spiral-shaped coil of wire while in the farther half is a metal disk placed near the opening in the parti- tion. Into this disk the innocent ashes are made to fall. A Convenient Holder for Dental Floss OU can clean your teeth after every meal very quickly and conveniently with the dental-floss holder illustrated. No bulky acces- sories have to be carried about, only a small glass tube an inch-and-three quarters long which can readily fit into a small pocket. ~ The floss is contained in this tube and when wanted for use a short projection on it is slipped out to receive the end of the floss. The accumulations of food between the teeth can now be quickly and easily removed. The floss is tasteless. Dentists claim that. such use of the floss is abso- lutely necessary for cleanliness. Fn eal lating power Pt IR " Xv f Ta ee The coil of dental in the jar is . drawn out, one length at a time, and this length is held in posi- tion for use Popular Science Monthly A Stimulating Climate May Be the Cause of Suicide sy N estimating the relative stimu- of the various climates of the world, Ellsworth Hungtington (‘‘Civilization and Climate,” Yale University Press) says that in Eng- land the mean temperature of the seasons and the degree of storminess are both highly favorable, while the seasonal changes are only moderate. q “On the. other hand,” writes Mr. Huntington, “Germany is above medi- um in temperature, and high in seasonal changes and storminess. In this respect, it resembles the north- eastern United States and southern Canada. Japan is similar except that it is somewhat - too warm and damp. The coast of British Columbia and the neighboring states is highly favorable in mean temperature, and medium in storminess and seasonal changes. Around San Francisco, the mean tempera- ture. is still better, but both seasonal changes and storms are mild. In,compen- sation for this, however, there are fre- quent changes of temperature because fogs blow in from the ocean, and are quickly succeeded by the warm, bright weather which generally char- acterizes the interior. Farther south where the fogs cease, the conditions become less favorable from the point of view of the changes from one day to another, although the mean temperature of the seasons still. remains advantageous. ‘“‘The chief defect of the climate of the California coast is that it is too ° uniformly stimulating. Perhaps the constant activity which it incites | may be a factor in causing nervous disorders. When allowance is made for the fact that California’s urban population is relatively smaller than that of states like Massachusetts and New York, insanity appears to be even more prevalent than in those states. Moreover, the cities of the California coast have the highest — rate of suicide. In proportion to the population the number of suicides is greatest in San Francisco; then come San Diego and Sacramento; while Los Angeles and Oakland are exceeded only by Hoboken and St. Louis.’’ Possibly these facts may be connected with the constant stimula- tion and the lack of relaxation. ee { ie floss Making a Coin Disappear at a Word of Command ERE is a clever method of causing a coin to disappear. The apparatus required is very simple and easy to make, and the effect is satisfactorily perplexing. The manner of disposing of the inner cup with the coin. Its hook catches on the coat sleeve The performer extends his left hand which holds a small circular metal cup, or box, painted some bright color on the outside and jet black on the inside. Transferring the cup to his right hand he asks a spectator to drop a coin into the box while it is thus extended. The left arm and hand are now outstretched and shown empty, and with the right hand which still holds the cup, the left arm sleeve is pulled back and the metal cup containing the coin is placed in the palm of the left hand as in the illustration. At a command the coin vanishes and the box can be closely examined by the audience. The trick is accomplished as follows: The cup contains a smaller cup which fits in it very easily and this smaller cup is lined and covered on the outside with cotton dyed a jet black to match the inside of the metal cup into which it fits. A small wire is attached to one side of it and extends upward, terminating in a hook. This smaller cup, which is only half as high as the one into which it fits, is slipped into the larger cup, the black wire hook which extends over the edge being kept covered with the thumb. When the coin is dropped into the box it fallsinto theinnercup. This is' done while the box is held in the right hand. When pulling back the sleeves of the left arm this hook is allowed to catch into the cloth of the coat, which auto- matically pulls out the inner cup containing the coin. The covering of black cotton on this inner “fake’’ deadens all noise. Any boy can do this stunt after five minutes’ practice and will find it baffling, although | it is one of the professional magician’s most cherished little secrets. It is needless to say that the performer must stand slightly to one side so that no one can see the hidden “fake’’ when it catches on the coat sleeve. Photographing Magnetic Field Lines: Without a Negative HE method described will produce perfect photographs, if the directions are followed carefully. In a dark room, lighted only with a ruby light, place a The lines of force taken on by the iron filings when placed over the magnetic field magnet beneath a non-magnetic surface. Place on this surface a piece of developing paper with the sensitized surface up, and on this sprinkle iron filings in a thin layer. 9SI 282 A slight tap of the paper will cause the filings to take on the lines of the magnet force beneath the paper, as shown in the illustration. It is necessary that the printing paper be handled in a dark room and exposed to a light only after the filings have taken on the lines of force. After the paper is exposed to the light long enough it is developed in the usual manner. Blue prints may be made in the same way but the paper must be printed in the sun- light.—ALEXANDER V. BOLLERER.- A Gas-Lamp Riddle for a Store Window Display GAS-FIXTURE dealer in Brooklyn, N. Y., who was something of a window display expert as well, recently hit upon an The lamp is suspended by wires and is with- out -visible connection with the gaspipe line ingenious scheme for attracting attention to his window. From an inverted U-shaped gaspipe he suspended by two fine wires a gas-lamp of the inverted incandescent- burner type. The wires were attached to a T-joint from which the lamp hung. The lamp burned brightly and attracted crowds just as he knew it would. Nobody could solve the riddle as to how the gas got into the lamp? The answer was this: Two tiny holes were bored in the upright posts of the U-bend. The holes were aimed exactly at the holes in the end of the gaspipe T-joint. Below the window, the U-joint was con- nected to the gas-main. When the gas was turned on, it shot from the two small holes straight into the ends of the T-joint and the lamp was lighted. Popular Science Monthly Cleaning Steel Pens with a ‘Glycerine Sponge ob illustration shows a European idea that is said to be a decided improve- ment on ordinary pen-wipers. It is a rubber sponge, wet with glycerine and placed in a glass holder. The sponge does not dry and is always ready. Glycerine takes up liquids readily, and it absorbs the ink from the pen by a mere con- tact or capillary attrac- tion. A thin layer of glycerine adheres to the pen and preserves it, making it take the ink at once when dipped. Glycerine-dampened sponge pen-wiper Bending Brass and Copper Tubing Easily HE following is an easy method of bending brass tubing so that it will not kink or split in the seams: Plug one end of each tube with a piece of soft wood. Place the tubes in an upright position and fill them with hot melted resin. The resin may be heated in a glue pot or a similar utensil. When cool the tubes can be bent to any desired shape. After bending, the resin is removed by holding the tube with the tongs or a rod and applying a blow torch, bunsen burner or other flame. The resin will run out and the tubing will retain its shape.—G. W. JAGER. A Cigarette Holder Which Expels the Burned End HE illustration shows a new cigarette holder fitted with a convenient device for expelling the burned end. This consists of a split ring which fits in the end of the holder as shown. On the outside is a pro- jection joined to the ring so that by push- ing on it the split ring can be slid par- tially out of the holder. The cig- arette is inserted The split ring holds the cigarette end when the ring oc- cupies the inside po- sition. To throw out the burned end, slide the button for- ward. This opens the split ring and frees the end of the cigarette. i ee Utilizing Tin Cans to Make Containers for Dry Batteries ‘HERE seems to be very little use for the emptied tin can—the kind in- which soups and vegetables are sold. How- ever, one inventor has proven their worth by using them as containers for dry batter- ies. The illustration shows three of these tins taking the place of zinc cylinders as the containing vessels and positive element of the cell. They were prepared in the following manner: The inner contents of four old exhausted dry cells, consisting of powdered carbon, peroxide of manganese and graphite, or black lead (plumbago) were taken and reduced to a powder by crushing with a mallet. Four disks of white blotting paper were cut to fit the interior of the bottom and the same number of pieces were cut to lay in around the interior of the can, care being taken to have about °4 in. project above the top so as to form a fold over the edge of the can. The blotting board was so folded at the bottom that it made a turned- in portion, and two more disks of blotting paper were then pressed into the interior to make a complete cell or well of paper all around the inside and bottom of the can. The dried material was then wet with a saturated solution of equal parts of chloride of zinc and sal ammoniac so as to convert the mixture into the same dry state. Each carbon-rod that had been removed from the old cells was heated at the bottom-end and for half its length in the flame of a gas-stove, and then allowed to cool. The cans were then filled nearly to the top with the chemical mixture which completely soaked the blotting-board lining. The second and third cans were treated similarly by pouring the contents of the first into the second and then into the third. The cans were then turned upside down foi a short time until the lining became well soaked with the saline solution. Then they were ready for the filling. A couple of tabléspoonfuls of the dampened carbon mixture was then placed in each can and a carbon-rod that had been dipped in the saline solution was pressed into the mixture. More of the carbon mixture was placed in around the rod and rammed down tight with a stout piece of wood driven with a wood mallet. The filling and ramming was continued until the can was filled to within 14 in. of the top. The wet blotting-paper lining was then carefully turned over the top of the carbon mixture and pressed Popular Science Monthly 283 down with the flat end of a clean stick, care being taken to keep the carbon mixture from flowing over and connecting the carbon-rod with the metallic part of the can,-thus forming a short circuit and quickly exhausting the electrical energy generated. The cell was completed by covering the turned-over edge of the paper lining with a little dry sand or a mixture of dry sand and plaster of Paris. It was then filled to the brim with melted pitch. Common resin may be used for this pur- pose, but it is more expensive. Each cell should test about 6 amperes. Ordinary tin cans used for containers for the positive element of a dry cell battery The three cans coupled in series gave about 21% volts, which rang a bell with consider- ‘able viger. After several weeks of use these tin-can cells showed no decline in power. Connections are made just as to the ordi- nary dry cell—ALFRED J. JARMAN. An Oil-Gage for the Automobile Gas-Tank, Made from a Broomstick AKE a broom handle and saw off a 2-ft. length and saw a slot in one end to fit over the pet cock oil-gage. With this gage you can measure the gas and reach under the fender and see if the cylinder oil is right without getting the hat or coat soiled. 284 What Do Your Tires Cost You a Mile? CHART for calculating the cost per mile per tire of an automobile has been circulated by a manufacturer - of Colum "4" Colum "3" Colum "c Tire Cost Tire Tire Cost. Per Mile Mileage $100.00 20.0 Cents $90.00 8.0 " 7.0 ” $80.00 pha - 5.0 ” $70.00 es S 1500) $60.00 : 3.0 " $50.00 2000 2.0 ” $40.00 1.0 $30.00 : +80 -60 = $20.00 +40 +30 " $15.00 A +20 ” $10.00 aeag Te) ” 10000 $9.00 -08 “ $8.00 a ¥ 12000 $7.00 4000 +04 " $6.00 16000 18000 $5.00 0000 A chart by means of which you may quick- ly find the actual cost of a tire per mile automobile tires. Given the cost of the tire and the number of miles it is used, a pencil and a ruler will determine the exact cost of a “‘tire mile’ in an instant. Con- sulting the chart which is reproduced here- with, we will suppose, as an example, that a tire cost $15 and was used 2,500 miles before it wore out. The ruler is laid from the $15 mark to the 2,500 mile mark and the line A—A drawn. Where the pencil line intersects the central vertical line, the precise cost of the tire per mile is shown. House Plants and How to Care for Them HROUGHOUT the winter months flower lovers must depend on window- box gardens, unless they possess green- houses. A satisfactory and attractive window-box may be made as follows: Take a box about 8 in. deep and cover the bottom of it with stones or broken pottery for drainage. On top of this place a layer of moss to prevent the soil from working Popular Science Monthly down and clogging. the openings betweer the stones. The stones and moss together should take up about 2 in. of the depth of the box. Fill in the remainder with soil to within 114 in. of the top. The length of such a box depends on the width of the window. Its upper surface should be level with the window-sill. The supports may be brackets, a table, or legs permanently fastened to the box. To allow for more complete drainage, bore holes in ~ the bottom of the box and place a drip pan beneath it. The watering of the plants will depend on weather conditions. On cloudy days in winter about once a week will be sufficient, while during the early spring months watering may be necessary every day. But even then the top of the soil should be allowed to dry occasionally. lightly and frequently than heavily and at longer intervals. The kinds of plants that will grow readily are begonias, ferns, geraniums, Kenilworth ivy, smi- lax and aspidistra. plant will thrive even though ~ neglected, and direct sunlight is not essen- tial for it. . In addition to those mentioned for the window-box, palms, rubber plants and cacti may be grown in pots. The regular potting soil should be used, which consists of I part compost, I part good loam and I part sand. Although not essential, it is well to add 1/20 part of bone meal. A potted plant must be examined from time to time to see if it needs a larger pot. This is done by inverting the plant when the soil is moist and tapping the pot until the soil and plant can be lifted out of the pot. If the ball of earth is entirely covered with roots it should: be placed in a larger pot and new soil tamped firmly into the space around the ball. To force the blossoming of geraniums indoors during the winter, the root growth should be restricted and the plants kept fairly dry. A potted fern must be kept moist all the time, but it must not be over- watered. Ferns should be given a bath occasionally by placing them in a tub and using weak suds made from a mild soap. All dust accumulation as well as minute insect parasites will thus be removed from the fronds. The suds should be rinsed off immediately. Palms should be watered regularly, but should not be kept moist. It is better to water © The latter —_— ane errr Be : Popular Science Monthly A plant that is too large for the suds bath should be sprayed with clear water. Small quantities of bone meal and wood ashes must be stirred into the soil occasionally, or the plant may be watered with liquid manure or ammonia water—a teaspoonful of ammonia to I qt. of water. ; Rubber plants ‘are given treatment similar to that of palms, but the soil should be kept more moist. Oleanders are treated in the same way. Aspidistras require less water than the palms and rubber plants. A dry sandy soil is required for the cacti. Heating a Rusty Nail to Loosen It for Pulling EN pulling a rusty spike from wood heat the nail head with a hot solder- ing iron, candle-flame or blow torch and it will come out easily. This method works equally well with rusty screws and screws that will not turn. How to Make an Adjustable Drawing- Board Stand RAWING-BOARD stands are usually clumsy affairs, at best, for a substan- tial support is neces- sary to keep them from toppling over under the weight. The illustration pic- e_ )'5"——> Seliciiats Sod tures a very strong stand, or supports ae eg for the board, to hold it in a sloping posi- ' tion, adjustable to “° dod 4 different heights and ke 2:2" >| mee ae | =r. i t 7 * oo A £4 SE, (aos) FRONT VIEW k—— 4} Details of the parts and manner of mak- ing the joints for the drawing-board stand xm 6 angles. The materials used in its con- struction may be of any straight-grained 285 wood suitable in appearance and cost. Good pine or poplar is appropriate. The following is a list of materials required: Z A 4 oa etmay, * seco | yy P| ’ ae eer A substantial drawing-board stand which is adjustable to any angle and height 1 Drawing-board 17 by 22 in. 2 Standards 27 in. long, 3 in. wide and 1 in. thick. 2 Sliding standards 30 in. long, 3 in. wide and 1 in. thick. 2 Rails 26 in. long, 3 in. wide and 1 in. thick. 2 Rails 24 in long, 3 in. wide and 1 in. thick. 2 Rails 22 in. long, 3 in. wide and 1 in. thick. 1 Rail 24 in. Jong, 2 in. wide and 1 in. thick. 1 Top board 26 in. long, 8 in. wide and 1 in. thick. 2 Pieces for the feet, 16 in. long, 3 in. wide and 1 in. thick. 2 Braces 10 in. long, 3 in. wide and 1 in. thick." 2 Braces 14 in. long, 3 in. wide and 1 in. thick. 3 Pieces for adjustable supports 22 in. long and I in. square. 2 Brackets for underside of board 4 in. long and 2 in. wide. 1 Board 22 in. long, 12 in. wide and 1 in. thick. 2 Bolts 14 by 2% in. with thumbnuts. The drawing shows the manner of cone struction. The main standards or supports are joined together by four cross-pieces or rails fastened in place with dowels or long wood screws. If screws are used procure round-headed ones. The braces are fitted in on the proper angles and fastened with screws. The two upper and longest cross- pieces are fastened to the edges of the stan- dards to make a space between for the sliding standards. The sliding standards are joined at the 286 | Popular Science Monthly — < upper and lower ends with a cross-piece, and a slot is cut in the lower part for the bolts. One edge of the lower part on each standard is notched or cut like teeth on a rip-saw. These are for holding the lower ends of the adjusting pieces for the drawing- board. A ¥-in. hole is bored in the upper part of each lower standard 6 in. from the top for the bolts. The top is finished with a board to make a lamp-shelf or a place for data sheets. The rail 24 in. long is cut to make a round pin on the end about %4 in. in diameter, and a 34-in. hole is bored in each upper support 10 in. from the top to receive the pin. On this rail a board is fastened so that a small box may be made on the rail above it to hold pencils, penholders and ink. One edge of the drawing-board is fastened to the lower edge of the board to make the whole into one built-up piece, forming a notch above the drawing-board to hold the drawing outfit and rules. The finish may be as elaborate as de- sired; but for this stand a good stain was applied, aftersmoothing all surfaces with fine sandpaper. Thena good coat of wax was given instead of varnish.—N. J. PARKER. Enlarging Wooden Pulleys by Building Up the Face HERE wooden pulleys are used on the main shaft and more speed is desired of one or more machines, it is not necessary to purchase larger pulleys. If a 10 in. pulley is in use and one 12 in. is wanted, simply nail cleats, I in. square and as long as the pulley is wide, completely around the pulley face. Then lengthen the belt accordingly and start the ma- chines. The increase in speed will more than pay for the trouble—Epwin R. Mason. Vasettes Made of Copper Plate, Wire and Test-Tube fies vasette shown can be easily made by any one who has a ball peen-ham- mer, a small hand-drill and a vise. The base i is cut from No. 16°or 18-gage copper in any shape, such as a clover leaf, heart, circle or trapezoid. The base shown here happens to be a trapezoid design, the long side being 4 in., one short side 2 in. and the other side 3 in. It is shaped with the ball-end of the hammer to give the custom- ary beaten effect. The center may be raised or not as desired. After it is ham- mered it should be gone over with a file ard -emery-cloth and all sharp edges and corners — removed to prevent its. scratching the furniture. The container is a test- tube 6i in. ; long and 94 in. in diameter,which can be purchased at any local drugstore. or brass wire 12 in. match the _ base. One end is flattened and two 1/16-in. holes drilled in it about 34 in. apart. The standard is then bent in the de- sired shape around the diameter of the tube, after-which it is placed on the base and centered. Two corresponding holes are drilled in the base, and then Test-tube mounted in copper wire stand it is riveted. The test-tube is put in place and the wire straightened up at right angles to the base. Care should be used > not to crush the tube during this opera- tion. —FRANCcIS W. NUNENMACHER. Avoiding the Dust from Ashes in an Old Furnace Se prevent the, discomfort arising from the flying dust of coal ashes when handling a hot-air furnace in a house, the introduction into the ash pit of a perforated pipe connected with some convenient source of water supply, and controlled by a valve outside the furnace casing, is a great convenience, and nei- PERFORATED waTeRPipe ther difficult nor expen- sive to instal. The pipe should be of black wroughtiron and the perforations should not be over - 1/16in. in diameter. Dampening the ashes For the ordinary to prevent the dust ash pit 1% in. pipe, perforated about 2 in. apart in such a way as to spray the greatest amount of floor space, will be satis- factory. The accumulated ashes should be sprayed once or twice a day, or when attend- ing the fire. The connection can be made by the local plumber.—Emma G. WALLACE. The standard is of 3/16 in. copper long, hammered to- an iron rod or pipe. LTHOUGH appealing to red-blooded A lovers of the outdoor life, and offer- ing an outing which affords deep en- joyment to the vigorous, winter camping is not very generally indulged in. But a long snow-shoe tramp across country or a “hike’’ into the wilds at this season will give an experience delightful to the jaded seeker after novel outings. Due preparation should, of course, be made, bearing in mind the conditions. Outfits may be divided broadly into two classes—a pack sack and a sled or toboggan. The pack sack outfit is to be carried in districts where it is impracticable to use any conveyance; hence it must be light, and yet include the essentials of shelter, food, bed and tools. The problem of shelter is solved if log cabins are located at the proper points along the route, but as this is unlikely it will not be considered. The fact that a tent cannot be satisfactorily heated by a camp-fire in front, but demands a stove, puts it out of the pack sack class, so only open front camps will be considered. Several types of these shelters are on the market, of which the Baker tent, Miller’s “Forester” and the simple ‘‘Fly’’ may be mentioned as examples. With its awning and its head room the Baker is more comfortable, but heavier than the other styles. It is available in a wide range of sizes. The Forester is ideal for two men, being light and quickly and easily erected, requiring but a tripod of poles; but it is rather cramped for head room in a storm-bound camp. Properly pitched, it is, however, the best storm shelter of the three. The “Fly,” which is simply a tarpaulin fastened on a slant frame of poles, is the simplest of all, but requires more work in pitching. Should you ever be benighted in winter woods with but a single pair of blankets, use one to make a fly shelter like the one shown on the following page. The important feature of all these open-front tents is that the slant of the roof deflects the heat of the fire to all parts of its floor. Three pairs of good wool blankets, or their equivalent in quilts, is about the minimum for comfort. Rolled up in the tarpaulin or tent the blanket pack is easy to carry. The axe is carried in the belt or thrust in the end of the blanket pack. It should be about 2 Ib. in weight with a 20 to 24-in. handle. Make sure of the reliability of the handle. Fold several plies of tough paper (anv paper will do in a pinch) over the edge of the axe and tie it with a string. No matter how sharp it is the axe will not cut through this muzzle. The usual light cooking outfit consists of I mixing pan, inside of which nests: I two- quart tin stew pail, I tin tea pail, slightly smaller; 2 tin or granite cups; 2 tin or granite plates; 2.large spoons; 1 long- handled pressed steel fry pan. These can all be carried in a small cotton sack. For all culinary operations use a hunting knife. Leave table knives at home, and use a pointed stick for a fork. An aluminum baking reflector with an 8 by I2 in. pan, is a convenience that will add much to the variety of the fare. With its board the weight is 3 to 4 Ib., but it is possible to do the baking in the fry pan. Sled or Toboggan Outfit Deep snow makes otherwise impassable country an open road to one wearing snow- shoes. Load the outfit on a toboggan. With the improved weight-carrying capacity 287 288 afforded by the toboggan the light outfit may be augmented, and the comfort con- eo eeeUly increased, by the addition of Popular Science Monthly cross-cut saw is a great labor saver. Protect the teeth with the grooved strip which came vith the saw from the hardware store, 1 robe about 6 by 6 ft.; 1 tarpaulin; wall tent, 7 by 7 ft. to 8 by Io ft.; 1 cross-cut saw, 414 or 5 ft.; handle; collapsible box stove about 12 by 12 by 24 in., with pipes, and bottom- hinged end door. Sleeping bags are good if made lie: but with tarpaulin on the brush of the bed, one pair of blankets under- neath and two pair over, with the robe covering all, you have a combination equal to most bags, without their high cost. See that the tent is fitted with a stovepipe ring just in- side the door. Remember that most tenting materials are very inflammable. The so-called balloon silk burns without smoke, smell or flame. The silk fabrics and mixtures are ideal for lightness and im- perviousness to moisture. A box style camp stove is better than one fitted with an oven in that the former is all fire- box. Have the door nearly the full size of the end and hinged at the bottom. On this door, propped up at the correct angle, a fry pan of dough may be baked. In supplying the demand of a winter camp for a bountiful supply of wood the I axe 314 or 4 |Jb., full and lay it flat on the bot- tom of the toboggan. The handles may be _ pushed into the end of the blanket pack. The provision list for a winter trip will be practically the same as for increase in the heat produc- ing fats and sweets—bacon and sugar. Itis impossible, of course, to carry any canned fruits or vegetables. Modern dehydrators have made available a great va- riety of vegetable food, and there is a milk powder which makes a_ passable parody on the natural article. ee Should the trip be but With its awning and head room oR ee the Baker is very comfo-table Sey eeeera es ~ a short one, hunger may be satisfied with sand- wiches Sat: other substitutes for real food, and the treat of camp bread, called in the Canadian West ‘‘Bannock”’ will be missed. It consists of flour, baking powder, a little-salt, sugar and shortening med with water to as thin a dough as can be kneaded with the hands into a 4% or 34-in. disk, the size of the pan. It is then baked before an open fire. Any or The fly tent is simplest but requires more time to pitch. It is a tarpaulin fastened to a slanting frame of poles flour and water, may be omitted and the resultant Bannock still be very palatable. Be sure to have sufficient food for the trip, but not an over supply to make the load too heavy to carry comfortably. summer, with perhaps an- all of these ingredients, except the’ Se oe yr Fionn bis Sut A Popular Science Monthly Personal Equipment Woolen underwear, toque, mittens and socks, a heavy shirt, waistcoat and sweater, with a sheep-lined or mackinaw coat for extra cold snaps, are very necessary. A pair of tweed trousers under khaki overalls will keep out any storm. True; the cotton overalls wet up easily in snow, but they dry quickly when hung up in camp. A slipper made of harness-felt sole and cloth vamp, with two pairs of socks, 289 firewood trees. Dig out the snow, if deep, with the snowshoe. Pitch camp facing at right angles to the wind. If it is stormy, bank with old logs, brush or snow, or all three. If faced directly away from the wind, the eddy formed by the tent will suck the smoke back into the camp. Cut and thaw out enough evergreen bough tips to make the bed and also to carpet the rest of the camp floor. The secret of an all-night open will be ample protection for the feet. Excepting in wet snow, chrome tanned horsehide moc- casins are the best winter outer footwear. I have had much comfort in all weathers out of a pair of leather topped rubbers, but the only foot covering that can be used satisfactorily on snowshoes is moccasins. Ordi- nary rubber shoes are excellent to wear around camp in the evening. In most localities winter is in the closed season for game, but if the possession of a rifle will add to the enjoyment, take it along. Carry it in a loose mouthed cloth or canvas case. On preparing to shoot, take off your mitten, run the hand up inside the case, grip the rifle and slip off the case, allowing it to hang over the left arm. Treated in this way the muz- zle, sights and hammer are al- ways clear of snow. Do not bring the rifle into the heat of the camp fire unless to clean it. Water condenses in the bore and action, inducing rust spots. Articles such as matches (some in waistcoat pocket and some in the safe), compass, sewing outfit, coil of snare wire for repairs and small whetstone need but passing mention. The deceptive weakness of winter sunlight, the slowness of the emul- sion in intense cold, and the danger of electric markings on a hastily wound film are points to be remembered in taking photographs. Keep the kodak away from the warmth of the fire. Making Camp Choose a level, clear spot in a thick clump of trees, in close proximity to some dry, This tent is ideal for two men, being light and easily erected with a pole tripod fire is in the use of large logs. Cut dry trees into about 6-ft. lengths and reserve the larger butt logs for bed-time fire fixing. Build a back re- flector to the fire by piling up four or five of the greenest logs that can be procured. If two trees can be located, properly placed, against which these logs may be propped, the camp may be set up to suit them. The heat that would otherwise radiate from the other side of the fire and be lost is thus conserved. Do not attempt to fry bacon over the big camp fire. Draw out a bed of coals or make a small fire at one side, the size of the pan. If camp- ing in a closed tent it will be necessary to use a collapsible stove. To keep a fire all night, put in two halves of the largest blocks it will hold and choke the draft hole with ashes. Further checking of the draft may be effected by partially opening the top lid nearest the stove pipe. Dig down nearly to the ground when getting snow for melting into water. There it is nearly all ice crystals, and contains much more water than the new, fluffy, top snow. See that none of it sticks out over the side of the pailin melting, for its ability to acquire a smoky taste is remarkable. 290 A rolled up coat or dunnage bag is a good substitute for a pillow and when these are not available put a block of wood under the brush at the head. The extent of the provision supply will be governed by the proposed duration of the trip, but do not figure too closely. Better come out with a surplus than be hungry. Removing Automobile Engine- Valves Enclosed in a Sleeve N automobile engine-valve set in a sleeve is rather difficult to remove at times owing to the fact that both sleeve and valve must be removed at the same time and the former is apt to bind in its casing. A simple method is to remove the lever-arm that depresses the valve-stem and slowly turn over the motor-shaft. The air compressing under the valve will drive it from the cylinder-head. A Bolt Washer Used for a Nut Lock O prevent bolts or nuts from becom- ing loose through vibration, a special metal washer, as shown in the sketch, may be inserted between the head of the bolt and the surface of the wood or metal. The washer A may be made of sheet iron or brass about 1/32 of an inch thick. After 5 the bolt has been a grip the washer firm- ly, the edge of the washer is made to turn over the edge at B, while the other 44 NOON \y - Z—~ <1=-D i )\ \ y Seria Metal washers with corners turned up to make the nut vibration-proof when it is set projecting end is bent up around the nut or head of the bolt. In this way the washer grips the nut and prevents it from loosening. The corners of the washer are shown bent in their holding position at C and before bending at D. Such a washer is only applicable to bolts and cap screws where they are used in pairs and close together. Popular Science Monthly Making a Kick-Mobile for Snow and Ice HE illustration shows how the kick- mobile may be used for winter sport by substituting a skate-runner for the A skate-runner makes an excellent substitute for the wheels on a skate-mobile for winter sport wheels. If it is difficult to remove the wheels from the kick-mobile the entire skate-mobile can be made as follows: The main part or foot-rest consists of a board 18 in. long, 4 in. wide and 1 in. thick. The bottom view of this is shown at A. The shape of the board represents a large shoe- sole, on which a block B, also the shape and size of the shoe-sole, is fastened. This is used for a base on which to clamp the skate, just as you would fasten it to a shoe. The steering-post is a broom-stick with its ends squared off, or tenons made to fit into mortises. The mortises for the handle are cut into the crossbar in its center and in the front end of the base A. These should be made a close or drive fit to make them solid. The details of the upper end of the po and handlebar are shown at C. Glue and brads fasten this joint in place. A little to the rear of the central part of the plat- form, a block D 1% in. thick is screwed on and used as a buffer or stop for the heel of the shoe. It is best to use hardwood for all parts and to paint or oil the surfaces when the machine is complete. The skate may be removed for sharpening at any time. On snow roads it is not necessary for the skate to be sharp, for a dull skate will run satisfactorily. a= ene he ee) ee eS Ye . A i ak ee WE Pea wy EN ae a Oe ee / A Craftsman’s Combination Foot-Lathe An inexpensive combination scroll-saw and wood-lathe By C. H. Patterson “IMPLICITY and economy have been kept in view in designing this combina- tion lathe. It will swing 6 in. above the bed and 4 4 in. above the tool-rest sup- port, and it is about 18 in. between centers. The swing can be made greater by increas- ing the height of the head and tail stock- standards, and the length of the bed can be increased to 4 ft., if a third bend is made in the crank as shown in the cen- ter line drawing. In this case, it will be necessary to use a crank of larger di- ameter, say, 14 in. The bed of the lathe is made of two hard- wood timbers 36 in. long, 4 in. wide and 2 in. thick, sepa- rated, as shown in the end elevation, by I by 3-in. pieces, to which they are bolted. The left piece forms a part of the outer stand- ard, as shown in the detail drawing of that standard. The legs are of stock 3 in. wide and 2 in. thick. A triangular piece is sawed from an upper corner of each leg. These pieces are nailed to the outer surface of the legs, care being taken to place them so that they will not be in the way of the holes bored for the bolts. These holes are then bored and the legs bolted to the 1 by 3-in pieces mentioned. It will be seen that the triangular blocks provide parallel surfaces for the heads and nuts of the bolts that pass through the legs. The crank is of I-in. iron, bent as indicated in the center drawing. This will be a job for the blacksmith and machinist, but the cost of the completed crank should be small. For a distance of 1 in. inward from the ends of the crank, it is turned to The lathe as it is used for turning wood. At- tachments may be applied for other kinds of work a diameter of 34 in., to provide bearing surfaces. Pieces of 4% by 3-in. stock are screwed across the outer sides of the legs. To the inner surface of these pieces are nailed other pieces of I-in. stock, in which holes should be bored to receive the bearing-ends of the crank. A strip of 1 by 4-in. material is nailed across the back of the legs and to it are screwed the hinges upon which the pedals swing. The pitmen may be cut from a | I-in. board. Holes are bored in them to receive the cranks. A central slot is made with a saw-cut in the ends of the pitmen for about half their length, and the parts are pried open and slipped on the cranks. Some pieces, I by 3 by 4 in. are nailed to the lower side of the pedals and nails are passed through them and through the pitmen. Half round strips are nailed across the pedals near their free ends for the feet to rest upon. The drive wheel is built up of three series of segments cut from I-in. board, preferably of hardwood. The single spoke in this wheel is also built up of three pieces. The central piece of the three must extend well into the wheel-segments. These segments can be sawed with a band-saw. The hole in the spoke that receives the crank-shaft should be bored true in a boring machine. A smaller hole is bored through the spoke to receive a pin, for pinning the wheel to the shaft. After the wheel is mounted, a board may be clamped across the legs, close to the wheel, for a 292 Popular Science Monthly rest in-using a turning gauge, for truing the wheel. The outer standard of the head stock is made of stock 3 in. square, and the inner standard of 2 by 3-in. wood. Holes 114 in. in diameter are bored through these standards at the proper height for mounting the spindle, which may be of %-in. shafting and about 12 in. long. Holes ¥% in. in diameter are bored vertically from the top of the standards to meet the 114-in. hori- zontal holes. These holes receive the babbit metal which forms the bearings for the spindle. Four pieces about 3 in. square ———Fa ie PRR j T 1 Vv Mf TAYE = RS ee ae Z [NOX 1 Le Ss HAN bs § == Soles | ay 7 OZAAA ZL ZEEE TEEE Za" “ZZ Z —Z GAZ FRONT ELEVATION OF LATHE metal. The can must be without soldered seams or joints. A sharp V-shaped lip should be formed in the rim of the can for pouring the metal. A handle for the can may be quickly made by twisting a wire around it. It is well to heat the spindle before pouring the metal, otherwise the metal may be chilled and the casting spoiled. The spindle may be heated by tilting the lathe sidewise and placing a small oil-stove or a large lamp below it. Having heated the spindle, place the lathe in an upright position and pour the melted babbit-metal END ELEVATION TAIL STOCK REMOVED Side and end elevation views of the lathe without its attachments, giving general dimen- sions for the larger pieces in its construction and showing the location of the parts are cut from a rather thin board, and 5-in. holes are bored through their centers. It is best to bore the holes before cutting out the blocks. These blocks are clamped or lightly nailed to the faces of the stand- ards so as to support the spindle in its true central position and in line with the bed of - the lathe. The parts of the spindle that lie within the standards should be wrapped with a single thickness of paper, which may be pasted to the spindle. Putty should be used to close all cracks so that the melted babbit-metal cannot escape. Old type metal may be melted in an old baking powder tin can, over an ordinary gas or gasoline burner, and used for this babbit- in the vertical holes, filling them well to their tops. When the metal has set, remove the retaining blocks and remove the spindle from the bearings and then take off the bits of wrapping paper. Drill lyin. holes down through the vertical extensions of babbit-metal to form oil- holes. The standards may be strengthened by bolting pieces of I by 3-in. material across their sides, above the bed. If the craftsman has access to a foundry, a pattern may be made and a casting ob- tained for the face-plate which may be drilled to fit the spindle, to which it is secured by a pin. Another method of attaching the face-plate is to cut a screw thread on the spindle and to drill and thread a corresponding hole in the face te. . Another method of making a face-plate is to thread the spindle to receive a large nut, to which a metal disk about 4 in. thick and 4 in. in diameter has been fast- ened with small machine-screws. It is well to have the surface of the face-plate turned true in a machine-lathe. Holes for I by 3/16-in. stove or ma- Popular Science Monthly 293 long. The hand wheel for the tail-spindle is made of two 34 by 3-in. wood wheels nailed together. One of these is bored to receive the bolt, and square recesses are cut into the inner faces of the wheels to receive the head of the bolt. Screwed to the tail-stock are’ two iron pieces, each 3 in. long, I in. wide and 4 in. thick. One of these is drilled and threaded to receive the threaded end of the bolt, and the other chine bolts are drilled and threaded in the face-plate. A babbit metal collar for the outer end of the spindle may be cast by building up a paper mold around the spin- dle as indicated in the draw- ing. The spindle should first be wrapped with a single thickness of paper as =r”, 2ZBAZ Ss for casting the bearings. Another way to make a collar is to thread the end of the spindle to receive a large nut. The rounded face of the nut should be placed next to the standard and the thread cut the proper dis- tance down the spindle so that the nut shall bind upon the end of the thread, before it binds upon the standard. Metal plates 3 in. long, 2 in. wide and \ in. thick are screwed to the outer faces of the standards to receive the end-thrust of the spindle. The pulley is about 334 in. in diameter and is secured to the spindle by a pin. The faces of the pulley and drive-wheel should be turned slightly convex. The support for the tool-rest is made of two wood pieces each 14 in. long, 2 in. wide and 1 in. thick, fastened together by means of cross strips, leaving a % in. slot between the pieces to receive the center bolt. Hand wheels 2 in. thick and 3 in. in diameter are used for tightening the nuts on the bolts of the tool- rest and tail-stock. The wheels may be turned from wood. The tail-stock is built up of three blocks cut from I-in. board. A slot to receive the square head-locking bolt is cut in the center block. The center block may be bored to receive the tail-spindle or it may be made of two sections as shown. The tail-spindle is a %-in. square head-bolt about Io in. ten why) LALSGL L Lo; Gy 4 Ges Details of the parts for making the jig-saw and tool-rest attachment and curves for crank-shaft of two lathes piece is drilled the full diameter of the bolt. A hand-wheel, bolt and nut are used for locking the tail-spindle. The head of this bolt is recessed into the hand-wheel in the manner described for the spindle-bolt. It may be necessary to cut the thread of the tail-bolt somewhat longer than the thread found upon it. The end of the bolt is filed to a conical point. A spur center is made by screwing a 3 or 4-in. wood wheel to the face-plate, passing the screws through the wood into the holes in the face-plate. The heads of the screws must be countersunk into the wood. Reverse thé position of the tool- rest, turn the lathe and mark the exact center of the wheel. Drive a nail for a center spur, file it and break off surplus 294 Popular Science Monthly length and sharpen the spur. Drive two smaller nails for drive-spurs and sharpen them in like manner. The distance from the center of the driving-spurs may be varied to suit the work in hand. A screw- center may be made by passing a wood screw outward from the center of another | wooden face-plate wheel. A simple strip of wood may be used in place of the wheels. Drilling may be done in the lathe by using square shank, bit-stock twist drills. Screw a wood wheel to the face-plate, find its center and cut a square tapering hole to receive the shank of the drill. Remove the tool-rest and in its place set a small but strongly made box about Io in. high and 5 in. wide. On the lower side of the box, nail a strip of wood 1 in. square. This strip slides in the channel in the lathe-bed and keeps the box from turning around. Move the tail-stock up to position and use the tail-screw for advancing the work against the drill. The material to be drilled rests against the left side of the box, and the screw bears against the right side. If round material is to be drilled, gouge out a semicircular channel in a wooden block, place it against the side of the box, and let the material lie in the channel. The jig-saw is supported by a baseboard 26 in. long, 6 in. wide and 1 in. thick, which is bolted to the bed by using the bolt from the tool-rest. The baseboard is slotted to receive the bolt. The standard which supports the saw-arms is fastened to the baseboard by a tenon and wedge, as shown. The standard may be of 2 by 3-in. stock. Added strength may be given to the standard by attaching a common shelf- bracket. Cross strips are nailed to the saw-table and to these strips and the base- board are nailed four supporting strips. The ends of the saw-arms are slotted to receive two pieces of flat iron each 21% in. long, 34 in. wide and 18 in. thick. These are drilled to receive the pins which pass through the arms, and the wing-bolts used for clamping the saw. The construction of the tightener for the saw is plainly indicated in the drawing. The saw is driven by means of a 4 by 3-in. bolt inserted about 114 in. from the center of a hardwood face-plate wheel, attached in place of the spur center. The head of the bolt should be countersunk into the wood and should be placed next to the face-plate, so that the bolt cannot by any chance come out while the saw is in use. A Hand-Brake for a Flexible Runner Sled VERY efficient brake for the modern flexible steel sleds may be constructed of the following materials: 2 small hinges and screws 4 bolts 44-in. in diameter and 2}% in, long 2 bolts 4-in. in diameter and 14 in. long 1 coil spring i piece of tire-iron 3 in. wide and 6 in. long I piece hardwood 24 in. long by 1 in. square I piece of hardwood 12 in. long, 3 in. wide and 1 in. thick I piece hardwood 2 in. longer than width of sled and 3 in. wide by 1 in. thick The long piece of wood should be rounded off on one end for a handle, then the three HINGES ° : the Ase I. The parts of the brake and how they are attach- [ 4-Th sprains ed to the sled on HINGE = i \RON pieces of wood are bolted together and the hinges screwed on as shown. After this part is complete the tire-iron is bent into an L-shape and two \-in. holes drilled in one surface and bolted to the end of the 12-in. piece. The brake is then ready to be put on the sled, by screwing the hinges to the long narrow pieces of the sled which run parallel with the runners. The spring is fastened between the 1I2-in. piece and the under side of the sled in such a way that it prevents the brake from dragging. A pull on the handle will force the iron into the snow and stop the sled. The spring holds the handle of the brake level with the top of the sled and is out of the way until needed to stop the sled.—Wo. A. LEECH, JR. ee 7 pe a ; 4 |e a Mel Bs The Snow Dari HIS is a favorite game-with the Cree Indian boys of Canada, and even the dignified warriors like to try their luck at the dart. It is a game for the snow, and may be played by two or more persons. SNOW SNAKE The snow dart is a piece of broomstick and the snow snake is cut from a tree branch The dart is 8 or Io in. long, whittled from a piece of wood about 34 in. in diameter—a piece of broomstick will prove just the thing. Shape the dart as shown in the drawing—the larger end bluntly pointed and the body tapering down to 4 in. at the other end. Finish it smooth with a scraper or sandpaper. For playing, a narrow groove or track about 60 ft. in length is marked out on the side of a hill or other slope. The track is then watered and allowed to freeze to make a smooth slide. At intervals along the slide make small barriers or bumpers, four being the usual number. The rule of the game forbids shoving the dart, and so it is merely placed in the groove at the top to travel down- ward under its own momentum. Of course the object is to slide the dart over all the four bumpers. If this is done four consecutive times by a person he wins the game, no matter how the score stands in points. The players may choose partners instead of playing individually, thus doubling the interest. The Snow Snake This game is likewise derived from the native American Indians and to the Wa- banaki tribe belongs the credit. It is played by two or more persons who skim or shoot small shafts or sticks over the hard or frozen crust of snow— similarly to the way in which stones are skipped over the water. The stick or “‘snake’’ may be thrown like the stone, butthe Wabanaki slightly crouches, with the left palm over the left knee, the stick resting on the knuckles of his hand, about 1 ft. from the head of the stick. The end of the shaft is held against the first and second fingers of the right hand, and issent on its course by a quick and forcible shove of the right arm ac- companied by the forward swingof the body. Throwing the snow snake so that it will skip over the snow like stones thrown on the surface of water Short lengths of branches are sometimes used, but the sticks of the Indian boys are about 3 ft. long, tapering from about 1% in. in diameter at one end to I in. in width at the head. The sticks should be smoothly 296 Popular Science Monthly Pe rounded and are preferably of ironwood, hickory, birch, or other rather heavy wood. The larger end or head of the snake is often slightly curved. Each player is provided with five sticks and each stick or snake is marked—the first with one notch, the second with two notches, and so on. To play the game, a line for the take-off is drawn across the snow. Each play- er stands on the line and takes turns in shooting the sticks. When all have shot the first shaft, the one which has traveled the greatest distance scores for the thrower one point. After all the one-notch snakes are shot they are gathered and placed at one side, and the snakes having two notches are thrown in the same way as the first round. The winner of the first round is entitled to the first throw in the second, which is scored in the same manner, except that the win- ner scores two points, cor- responding with the number of notches on _ his stick. When the stick with three notches is thrown, the win- ner scores three, and so on. 2 While a certain number of / points may determine the joo" duration of the game, wl i the Indian game ends ‘ | when all of the five i | | sticks have been | | thrown. y | x Double-Rim Fox Trail Thisisa particularly S_ good chasing game for three or more persons to play over the snow. As shown in the illus- tration two circles are marked off—the outer Baie BN aaa Snow dart runs down in- cline by its own momentum circle being about 4o ft. in diameter and the inner circle 10 ft. smaller than the outer one. The circles are then bisected with straight © lines, similar to the spokes of a wheel, the number of spokes depending on the number of players. At the points where the outer spokes cross the outer circle, the goals or dens for the foxes are marked off, allowing one less den than the number of - foxes. Choose a player for the hunter, who stands in the center, at the hub of the wheel. The other players, who are the foxes, take their. places in the dens around the outer circle, except one, who is the odd fox; he stands out- side the den anywhere on the outer circle. This odd fox endeavors to steal a den wherever he can. The object of-the game is for the foxes to exchange dens without being caught by the alert hunter and with- out allowing the odd fox to get a den. All players must keep to the trails and run only on the lines of the diagram, but they may run in every direc- tion on either of the circles or on the spokes of the wheel. It is not allowable for a fox to turn back on his trail, and once started he must continue to the next den. When the hunter tags a fox, the two change places. When played in deep snow, paths marking out the circles and spokes should be trodden down and well packed for the game. ON ee ee ere ee a See: Popular Science Monthly Russian Hole- Ball From Bessarabia—once a province of Turkey, but now a part of Russia—comes this interesting game. It is one of the few ball games which may be played in the snow and is suitable for from 3 to 10 players. For the ball the Russian boys use a frozen snowball, but a tennis ball or even a stone will serve as well. As shown in the illustration a number of holes are made in the snow, large enough to hold the ball. These holes are placed in a straight line and spaced 3 ft.apart. There should be as many holes as there are players, each player having a number. The holes are numbered I, 2, 3, 4 and so on. The take-off or throwing line, is drawn across the snow 10 ft. from the first hole, and at right angles with it. There the players line up. Player No. 1 stands on the line and en- deavors to throw the ball in one of the holes. If the ball falls in hole No. 3 the player scores three points, and player No. 3 takes his turn at tossing the ball. If the ball lands in hole No. 2, it scores two points for the thrower, and it is No. 2’s turn to toss the ball. The game is sometimes played by score— the player who first wins fifty points winning the game; but it may be varied by setting a time limit of say fifteen min- utes, the winner being the player scoring the most points during this time. Testing the Quality of Leather Belts with Vinegar LACE a small strip of the leather belt in strong vinegar and if it is of good quality it will not change except to turn a darker color; but if of poor quality the fibers will swell and become gelatinous. The double rim fox trail over which the chase is carried on 297 The Law of Retribution in the Insect World NE day on entering his study an old gentleman noticed that there was some powdered sugar spilled on a window sill. He was about to brush it off when he saw that an ant was running around the little heap. ‘‘Ah!” said the gentleman, who had a= scient:fic turn, “I wonder if that ant is a scout?” After a few more turns, the ant sudden- ly wheeled away from the sugar, ran to the outer edge of the sill and__— disap- peared over the edge. ‘Probably he has gone to carry news of his dis- covery,” said the ob- server to himself. “Here is a chance fora little experiment.” He then brushed all the sugar off the window sill, rubbed the place with a dampened cloth, then wiped the spot over with a little am- monia, so as to leave no trace or odor of the sugar. Then he drew up a chair and sat down to watch the result. Before very long a large party of ants appeared, lead as he believed by the one who had made the discovery, and was not content to enjoy the feast alone. They advanced to the promised land and then confusion began. They ran hither and thither, searched all about, gathered in a group and then—fell upon their guide and slew him. That was long ago, but the man who tried the experiment could not get it out of his mind. Here an honest hard- working, unselfish ant, who did not even pause to enjoy the treasures he had found, who hastened away to report his find for the public good, was deceived, betrayed, martyred—merely to answer a foolish scientific inquiry. Surely it was a case where virtue was not its own reward, where innocence was a victim.—TuUDOR JENKS. A Model Darkroom The average bathroom may be made to serve the purpose for the amateur By Wheeler P. Davey VERY small town has few accom- modations for helping the amateur with his developing and printing. The tendency of the American people is to have their work done rather than to do it themselves, and this is one reason for the existence of the professional film- developer. Another is a lack of ade- quate darkroom facilities on the part of the amateur photographer. It is the purpose of this article to give the principles which govern the ar- rangement of a good darkroom and to illustrate those principles by a detailed description of two darkrooms which have proved satisfactory enough to be called ‘‘model” darkrooms. In planning a darkroom, space must be provided for the stock developer solution, developing shelf, sink, hypo bath, wash-tank, drying-rack, shelf for plate-holders and _ printing-frames, ventilating-fan, necessary lights and switches. In addition to the foregoing it is usually desirable to provide room for a moderate supply of plates, films, printing paper and chemicals. The room should be planned so as to make everything as compact as possible. The less one is compelled to walk about in the dark the more attention can be paid to the actual work of loading,,. developing and printing, thus reducing the tendency to make annoying errors. If possible the room should be so arranged that everything can be reached by taking not more than one step. If, because of the shape of the room, this proves impossible, then everything should be arranged so that it is necessary only to walk along a straight line. It is absolutely essential that the developer should be kept free from hypo. Hypo usually finds its way into developer in one or more of the following ways: Hypo solution when spilled on the floor, dries, and is distributed about the room like ordinary dust; the hands wet with hypo and handling the bottles of de- veloper leave traces of hypo; electric lights are turned on while the hands are still wet with hypo, the hypo dries and is distributed as before; the fixing tray is used by mistake as a developing tray. This is especially likely to happen when the hypo tray is kept underneath the developing-shelf. With such an arrange- ment, the plate or film cannot be taken from the fixing-bath to be washed with- out dripping hypo on the floor. This source of trouble disappears when the fixing-bath is on the same level as the developing-shelf. The plate or film is thus taken out of the developer, rinsed over the sink, fixed, and washed either in a wash-box or in the sink without ever being held over the floor. By having the sink between the developing tray and the hypo, the hands may be easily rinsed off before commencing to develop the next plate or film. _ To prevent hypo being transferred to switches these may be turned on and off with foot treadles. These treadles are connected by stout woven cords to pull- switches such as can be obtained from any electrical dealer. In professional and semi-professional work, where plates are used to the exclusion of films, it will be found of advantage to use nickel-plated metal frames for fixing, washing and drying the plates. As soon as the plate comes from the developer it is put in a frame, washed in the sink and at once put in the hypo-tank. After fixing, it is washed in the wash-tank and hung on the rack to dry. The use of the frames will be found to keep the gelatin from being marred by finger-prints. In case films of fairly large size are used, these frames should be replaced by those sold for the purpose. Plans are given of two darkrooms. By slight modifications of one plan or the other the average bathroom may be — made into a serviceable and up-to-date amateur darkroom. The darkroom shown in Fig. 1 to 7 is" designed for use with films and plates up to 10 by 12 in. in size. The developing- shelf should be covered with a sheet of galvanized iron so as to prevent water - os ee Popular Science Monthly 299 1" SQUARE Ye LEAD JePINE SHELLACKED INSIDE AND OUT AND LINED nN b Sf, Gees ~ aa FI6.9. fA 7 <— 15" —— - - 7%," ~ 2°K2"> i i Wd FIG.8. FIG.2. TREADLES 2 Ss is bret FIG.10. = y CUPBOARD FOR Pre 2 Ee Y CHEMICALS pt 2% Yjil_o sSes 2 Y Bobs ects y rs TSoZp y) ‘AN FOR DRYING rial Y AT Ss = j VIEWING = — = 5 Y DRYING SCREEN z 5 y FERPAAE = =ae DEVELOPING TABLE Fa yj HYPO A sHEUF Y TANK re ran! ries Goin | >= DRAWER ] ! ve LIGHT _— on | / TREADLE FOR L -= 3 y) VIEWING SCREEN RED LIGHT Y FIG.11. Y Z Z y FIG.3. FIG. 4 GSS % GLASS OR HARD RUBBER BATTERY JAR Y) DEVELOPING Y TABLE , r Z ; 4 EBS i GR , - FASO =x vA. Z : (ES Ge a y Z - if y Y : y Z Z ° ° SSS hhh Ah SSS SSF FIG. 6. U} y : NLET % Y) F nas: METHOD OF HANGING CURTAINS pane — a GALVANIZED IRON TANK Plans of two dark rooms. one for the amateur and the other for the nrofeccional nhotacranher 300 Popular Science Monthly and developer from soaking through to the drawer below. The use of a water- bath for keeping the developer cool will be found a great convenience. It will be noticed that the running water in the wash-tank is in contact with the hypo- tank, thus insuring cold hypo. In case it is intended to work with only small plates or films the hypo and wash tank shown in Fig. 1 to 4 may be supplanted by the one shown in Fig. 5. This consists of a galvanized-iron tank 1 ft. square and 1 ft. high, which serves as a wash-tank. In this, at one end, is placed a glass or hard rubber battery jar such as may be obtained from any of the larger electrical dealers. This jar serves as a hypo-tank. The rheostat, Fig. 2, is a 300-ohm rheostat of half-ampere capacity and has all the range needed for dimming a 50- watt red lamp. If a “dimalight’’ is obtainable it will be found to be a satisfactory substitute for the rheostat. Care should be taken to paste a piece of black paper over the tip of the red lamp as the tips of such lamps are often uncolored, allowing white light to pene- trate into the room. In Fig. 2 the white light is shown as a 100-watt Mazda C-2 lamp behind a ground glass. It therefore serves both as a white light and as a diffuse light for printing. Attention is called to the use of cur- tains in the doorway as a means: of economizing space in case the dark- room is built out like a closet in a large room. Two curtains are hung on sep- arate rods as shown in Fig. 6. The out- side edges are fastened permanently to the doorway. The inside edges are fastened to sticks about I in. square. These sticks act as weights and prevent the curtains from blowing in and out, causing light-leaks. Each curtain is wide enough to stretch completely across the doorway. A suitable housing as shown, painted black on the inside, prevents light from leaking over the top of the curtains. The curtains are made of double thicknesses of galatea. Such a closet darkroom requires artificial ventilation or it soon becomes unbear- able. An adequate scheme for ventila- tion is suggested in Fig. 2 and 7. . The second darkroom is more elabo- rate and is more adapted to professional .use. The tanks and their arrangement are shown in Fig. 8,9 and 10. The cost of construction may be reduced by sub- stituting the hypo and wash tank shown in Fig. 5. Attention is called to the method of drying the plates with the fan. The hypo and wash tank is shown in detail so as to be a guide to any who may care to construct a similar one. In Fig. 11 the switches governing the various lamps are not shown. The treadles will, however, indicate where these switches should be placed. In Fig. 12 is shown the general arrangement of tanks in a closet darkroom. A Comfortable Collar for the Horse ADS used in the construction of any article add proportionately to its weight and in the making of horse collars the added burden is considerable; yet it is quite necessary to have sufficient Air cell substitute is more comfortable than the stuffed pads in a horse collar padding against the horse’s shoulder as a protection. The latest type of a collar made abroad is a pneumatic pad, built up similar to an automobile tire. Each side of the collar is a chamber of suitable shape to receive an inner air tube, which — is blown up with a tire pump. Not only is the collar lighter than the ordinary one but it will fit better on the neck of the horse. ee ee SL . Popular Science Monthly Making an Ejector of Pipe and Fittings (8 ejector is a difficult device to make and get the right proportions for de- livering water at different temperatures. One made with dimensions given will lift BUSHING Pipe connections to form an ejector for water of different temperatures hot water. The suction and delivery pipes are 2 in., turned into a tee as shown, the other opening being fitted with a reducing bushing to admit a %4 or I-in. pipe for steam. This pipe should be drawn to make a hole at the inner end not over in. in diameter. The end of this pipe should have a long thread cut on it for adjustment and a lock nut fitted to hold it in place when set. A Sharpening Block for Putting Keen Edges on Tools HISELS and plane-irons generally have a wire edge after being sharp- ened on a stone. This is best removed by rubbing on leather. Glue an old piece of leather belt on a small block and it will answer the purpose admirably. How to Drill Holes in Glass with a File Point OLES may be drilled in glass in the following manner. Take a pointed, three cornered file and dip it in pure tur- pentine. Put the point of the-file at the place where the hole is to be drilled and twist the file first in one direction and then in the opposite direction, bearing lightly upon the file. Slightly turn the handle of the file around in the hand and twist it some more. When no glass is cut add more turpentine. After the hole is drilled through it can be smoothed with emery cloth. Holes may also be put in’ very thin glass. Take a rod the diameter of which is the same as the diameter of the hole to be made, and place the end at the point - lathe, where it will 301 where the hole is wanted. Pack wet clay around the rod, and then withdraw it. Pour melted solder into the hole left by the rod. As soon as the solder is poured in, dip it into cold water and knock out the piece of glass——-LEsTER REINICKE. A Tool Post Chip Guard for a Lathe N CUTTING some kinds of metal the chips will fly from the tool edge and are apt to strike the eye or burn the flesh. The il- lustration shows a guard that is easi- ly fitted in the tool post of a guard the face. It consists of a square of metal with a projecting tang the size of the tool-post slot, the square opening being covered with a piece of celluloid. The face guard is lo- cated in the tool post © Small Auxiliary Oven for a Gas Range ERE cooking requirements are small the cost of heating a large oven on a gas range of the type shown may seem excessive, whereas a small portable oven set over one of the burners uses little gas. To overcome the incon- venience of storing it when not in use and of lifting it frequently, a metal shelf raised on flat iron brackets at a sufficient Extra burner attachment for a gas range height so as not to interfere with the free use of all the burners, may be erected over the stove. An additional burner should be fitted into the bottom of the oven and connected to the gas supply. The shelf extending out on the side of the oven forms a convenient warming place for plates—A. B. KENNEDY. 302 An Old Steam-Boiler Used As a Coal-Bin HE owner of a discarded fire-tube boiler made use of it in a very unique manner as is shown in the illustration. The tubes were removed and the boiler set up with the ash- door opening at the bottom. The fire-door was filled in with wood, and a box was ar- ranged at the ash-door to re- ceive the coal as it falls to the « bottom. The coal is put in at the top and set- tles down grad- ually as it is 50000000 90° 29D, ° = ° 6-2-0 So Selo re) ol oP oto Lo2o' The boiler set on end to be employed as a coal-bin removed from time to time from the box at the base.—HAMILTON A. HOOPER. How to Protect Mounted Curiosities from Dust OTHS, butterflies, lichens, leaves, etc., can be effectively pro- tected from dust by a case of simple con- . struction. Select two sheets of glass of the same size, and fasten the specimens to one sheet by a touch of glue. Then glue a strip of wood around the edge of the glass on the same side as the specimens. Next glue the other sheet of glass to the wooden strip and bind the wood with passe partout paper. Specimens will keep for years in excellent condition in such a case. To hang it, glue a piece of linen to the glass. A mirror hung in the back of the frame will reflect the specimens and add a touch of beauty to it. Crumb Tray Quickly Made from a Candy Box Pe inexpensive crumb tray for emer- gency use may be made from a candy box. Take the top part of the box and break off one of the sides. Then the side may be used for the crumb scraper and the remainder of the box for the crumb tray. moss, ~ Popular Science Monthly 4 Chemically Hardening and Dust- Proofing Cement Floors e's LIQUID preparation for chemically hardening and dust-proofing cement floors that have begun to crumble has recently been invented by a noted scientist. This product differs radically from the paints ordinarily used on cement floors, inasmuch as it hardens the floor through and through by a chemical reaction. a colorless liquid, very easily applied with a long-handled brush, which contains cer- tain chemicals that weld the loose particles of- sand and cement into a hard, solid, impenetrable mass. the color or appearance of the concrete in any way. . As this is not a mere surface coating which can wear off in time, but a prepara- tion that changes the very nature of the concrete, its benefits are permanent and it hardens and dust-proofs cement floors for life. In factories, where the dust from cement floors gets into the intricate working parts of expensive machinery and causes serious damage, this new preparation will be particularly welcome. Moreover, it renders the floor impervious to grease, oil and dirt, so that a clean, sanitary condition is easily maintained. An application of this preparation dries quickly so that its use does not interrupt business. If it is applied at night, the floor can be used next morning as usual. Fire-Escape Window Bracket with Lowering Basket HE illustration is descriptive of a fire- escape that is quickly fastened to any windowsill. .A strong basket arrangement is provided in which a person or persons may be lowered to the ground by ropes. The device consists of a bracket-support with two U-shaped arms which hook over the sill of the window. To the! ends of the outside somone arms are pulleys over which ‘ the ropes supporting “* for a Greene ; the basket are run. A short ladder is also provided as a means of getting from the room into the basket. _ Basket and rope de- eS It is It does not change | i ae Building a Farm Forge and Blacksmith Shop A Simply Constructed Housing for the Farm Tools By W. E. Frudden SMALL homemade forge for use on the farm is inexpensive and can be constructed so that it will give very good results. A tuyere iron, a few sacks of cement and about 175 ordinary chimney bricks with some stone and sand are all the materials that will be required. | es 16’ >i TE ee — el == and reinforce it with wire to prevent cracking. A makeshift blower can be made from two old disks of a disk-harrow bolted to a wood frame in position about 2 in. apart for the sides of the blower. The fans and the cover are made of sheet metal and this is geared to an old bicycle driving mech- al GAS ENGINE——* PUMP ALE TET TTT LINE SHAFT ooo CC CC CU _ ------- ----- -- - - - - - 2X4" RAFTERS! 2X6" CROSS-TIE = 8" BLOCK WALL : anism. A _ piece of 3-in. drain-pipe is to be connected from the blower to the tuyere iron on the forge. It will pay to pur- chase a good anvil 10! ee ee ee that has a clear ring -—— WORK-BENCH CUPBOARD Make the forge about 2 ft. square, with a concrete founda- tion placed below the frost line. To do this dig a hole 2 ft. square and 3 ft. deep and fill it with a lean mixture of cement concrete. Begin laying the brick on the hardened and set cement, which should be just level with the floor-line of the shop. Lay the brick the same as in making a square flue and draw in the side until the flange or tuyere iron will rest on ‘the inside edge of the wall about 18 in. above the ground. It is customary to have the blow pipe at the left and the shaker at the front so it will be best to use this plan in setting the tuyere iron. The brick wall is continued to the desired height and it is widened as fast as possible. Make the fire-pan 3 in. wide and 10 in deep, coat it well inside with rich cement _ A small blacksmith shop constructed of concrete blocks, with a concrete floor in which machinery repairs can be made at times on the farm to it and set it on a block handy to the forge. A heavy hammer weighing 4 Ib. is another one of the essential parts of the forge equipment. Anyone can then go ahead and make punches, chisels, hardies, swages, fullers and tongs. A good fire is necessary and good coal must be used. Wet the coal down well before putting it on the fire and coke it well before using it. Never let ‘the fire become open, especially when welding work is to be done. There is considerable to learn by experience regarding work on the forge, but there is nothing about it that is too complicated for the average farmer. Do not try to save money in building the 303 304 shop. Build it warm and provide for some sort of a heating apparatus. Have plenty of light and ventilation and make it a pleasant place in which to work. Provide enough room so that later on an emery wheel, lathe, drill-press and other ma- chinery for the farm may be installed as well as a lighting plant. Ironing-Board that Becomes a Bench and Step-Ladder N ironing-board which can be adjusted so that the operator may sit down to iron, and which may be convert- Popular Science Monthly flat surfaces and the desired result is obtained. For the brown marble effect; tint the color with burnt umber, burnt sienna and raw umber. For the black, mix some turpentine with’drop-black for the floating colors, using a dark lead color for the ground work. After the articles are per- fectly dry, they may be sanded lightly and varnished and also polished with a little crude oil and pumice stone. To treat marble tops, apply a coat of flat color for the ground. If in bad condition, adda second coat. ed into a bench for the tubs, a step-ladder, a sewing-table, or an invalid’s table finds a use in every. house- hold «t-te When the ground color is thoroughly dry and smooth, the desired colors may be stippled on. After dry- ing for five board is made of sound lumber strong enough for all the purposes for which it is intended. When not in use it folds up so that it can be placed in any out-of-the-way corner of the kitchen, closet, or pantry. How to Make Imitation Marble with Paints ERY good imitations of mar- ble can be made by the fol- lowing method: Procure a tank sufficiently large for holding the articles to be treated. The articles are first given a coat of flat ground color. For gray marble, apply a coat of flat white, which is made of white lead, turpentine and a little dryer. For brown marble, add a little raw sienna and burnt umber to the ground color. After coat- ing the articles, allow them to dry thoroughly; then sand them with No. o sandpaper. Fill the tank two-thirds full of water. To secure the gray effect, take some flat white and add a little drop-black, enough to make a light lead color. With an old brush, spatter it on the surface of the water. Add a little more black and spatter it on the water. The articles, previously painted and sanded, are carefully slid into the tank. The colors floating on the water readily adhere to the fl i nit l Combination iron- ing board, and step-ladder minutes, spatter on a solatign potash, the size of a walnut, toa pint of kerosene. The potash cuts the colors and the oil blends them together, producing a mot- tled effect. With a little practice, all the different marbles may be imitated. The work may be smoothed up and finished in shellac or varnish—JoHN L. JACKLIN. Removing the Cones from Ball Bearings on Magnetos - HE cones or inner races of the ball bearings used for sup- porting armatures of ignition mag- netos or small generators that supply lighting current in auto- mobiles are not easily removed by ordinary means. The common procedure is to force these on the shaft against a shoulder. When it is desired to remove a cone for replacement, the usual method is li HH table ! ) , ing in a cold chisel between the shoulder and the cone so that it acts asa wedge. Serious damage has been done by inexperienced repairers and mo- torists when attempts were made to remove the cone at the collector-ring end of the armature in this manner. The slightest carelessness or slip of the chisel usually results in breaking the ebonite or hard rub- prepared by adding a lump of © eh et ba to force this off the shaft by driv-— ee eee cone in an effective manner. Popular Science Monthly 305 ber insulating spool carrying the collector ring. _A simple puller may be easily made to remove cones from either end of the arma- ture-shaft without liability of damaging CIRCLE TO FIT BALL RACE Puller for removing bearing cones on au- tomobile magnetos or lighting generators anything. The puller is made of bar stock, either steel or iron, bent as indicated and having the jaws shaped to conform to the curvature of the ball race and circle of the cone. A tension bolt is used to hold the puller-jaws firmly seated on the cone-ball race and prevent their spreading. This is curved or offset at the center to clear the tension screw. When the parts are properly assembled, screwing down on the puller- screw which sets in the center hole of the shaft end, will remove the most obstinate This same type of puller, but of heavier construction, can be used to remove ball bearing cones from automobile front wheel supporting- spindles as well—Victor W. Pacé. Apply a Light Color to the Kitchen Walls EVER paint the kitchen walls a color that will not show the dirt and dust. A light color, such as light buff or a soft gray putty color is cheerful and not glaring, and it will make the owner work to keep the dirt out. How to Make a Support for an Automobile Frame © sche piece of garage and auto- mobile repair-shop furniture that can be made during spare time is shown in the accompanying sketch. It is especially val- uable in supporting the frame of an auto- mobile when necessary to remove a spring or axle, as the ordinary form of automobile lifting jack cannot be used to advantage under such conditions. The base is of cast iron, the mold being made from a simple wood pattern. The only machine work necessary is to bore out the center and tap it to fit the pipe. A pipe 2 in. in diameter will be suitable for small cars, though the 3-in. size illustrated is better adapted to general requirements of the average garage as it will sustain the heaviest pleasure cars and practically all trucks. The pipe is threaded at one end and screwed in the base-plate casting. Sometimes an ordinary floor-plate is used by bolting it to a substantial wood block or section of plank instead of the special casting, though the latter is neater and can- not crack or split. A series of 5-in. holes _ are drilled through the pipe, these being spaced as desired, usually 2 or 3 in. apart. Another casting is made for moving on the pipe. An arm projects as shown. No machine work is needed except tap- ping out for the I-in. set-screw, as the large hole through which the pipe passes may be cored in the casting to save expense. -To make doubly sure and prevent liability _Frame support or jack to use in places where an ordinary jack is not adaptable of set-screw slipping under a heavy load, a stop-pin is also provided, this passing through holes in the pipe and slots in the casting. This stand is useful in supporting front and rear axles for repairs and also for holding bar-stock when pieces are to be cut. 306 Popular Science Monthly A Portable and Adjustable Holder for Storing Round Stock N shops or storerooms where rods, pipés and the like are kept, some kind of a rack or holder should be provided to keep them from rolling about under foot. Finishing Aluminum Surfaces on a Buzz-Planer LUMINUM is a metal that can be worked with rapid cutting machines, the only drawback being in holding the pieces so that they will stand the strain and resist the cutting stress without dis- tortion. The practical limit thus far at- tained for cutting speed is 150 ft., and a manufacturer of aeroplane engines has used a _ buzz- planer for surfacing the alum- inum oil pans that go under 14 the engine crank-case. The igi - walls of these cases were only for Fx GROL? HOLES 1 in. thick and were hard to SPACED I" CENTERS. hold in an ordinary fixture, QO0OGOPOOOO so the buzz-planer was tried pO *sr—!0-—s | out with excellent results. Pe ee While more cuts had to be ig] taken, the speed with which The uprights are adjustable to accommodate a large or small quantity of stock and can be moved from place to place Stationary racks serve the purpose well, but they cannot be changed when a dif- ferent location for the material is wanted. The holder shown has been used with success, and it was not expensive to make. The wood used was picked up about the shop and one of the men doing carpenter work put it together. One rack is required for each end of the stock. Each standard is 18 in. long and 2 in. square, with two pieces, each Io in. long, 2 in. wide and 1 in. thick, fastened at right angles to the lower end as shown. The horizontal pieces are spaced for holes 1 in. apart, which are bored with a bit 7/16-in. in diameter. A %-in. bolt about 6 in. long is used to hold the parts together. If only a small number of rods are to be kept, the uprights may be pushed together, closing the space between them. When the stock is placed in the holders the weight keeps them firmly in position. Turning Small Screws in Difficult Places with a Wood Screwdriver AKE a piece of peg wood, or the end of a wood penholder, or match, or similar strip of wood. Shape the end into a screwdriver-bit so that it will snugly fit the screw slot. Such an improvised screw- driver will hold the screw firmly at any angle and will drive it almost home, when the process can be completed and the screw set up with a metal driver. each one was done made it possible to complete the sur- facing in less time than in the ordinary way. To Repair Nail-Hole Punctures in Rubber Tires Economically T is not necessary to paste a large patch on a small nail-hole puncture. Just as good results can be obtained in a much more economical way. Pick out the hole until there is a very clean perforation, then roughen with sandpaper. Apply the cement, allowing it to dry 25 or 30 minutes, and fill the hole with a small plug of tube- stock rolled up to fill the opening. Cure 5 minutes on the flat plate. The pressure will form the rubber plug into a sort of a rivet on the inside and the repair will hold just as well as a bulky patch. A Snowshoe Fastener Better Than Strings HE ordinary method of tying on snowshoes may be improved upon by making a fastener like the one illus- trated. The toe-clip A is of light harness leather, with straps B for attaching it to the web of the snow- shoe. The buckles C are for the straps B and the strap D engages the buckle E. This toe-clip can be adjusted even with cold fingers, in a minute’s time.—J. L. BAYLEY. Leather fastener for snowshoes ee ee Easily Constructed Step-Down Transformer HE greater part of the work of building a small step-down transformer is in the cutting and assembling of the iron. By securing the reactance core of a dismantled alternating current arc light there will be had a well proportioned and efficient core ready for taping and winding. These cores A laminated iron core of a discarded arc lamp used for a step-down transformer can be easily secured as, in a great many places, the new high powered Mazda and nitrogen lamps are replacing the old style arcs. The core I used was of the dimensions shown in the accompanying illustration. File the sides of air gap smooth and parallel; clean the iron, tape and then shellac it. When the shellac is dry wind on No. 18-gage double cotton-covered copper wire in even turns. For a maximum secondary voltage of 12 volts wind 120 turns, starting 1 in. from the opening on the inside circumference. Tape may be taken off at any turn, figuring ten turns for each volt. Wrap the secondary coil with linen tape; and cover with shellac. Over this wind 1100 turns of No. 26-gage double cotton-covered copper wire as evenly as possible. Cover the completed primary and core to the opening with black friction tape and then coat it with shellac. Cut a disk of -in. fiber and bore holes for binding posts as shown. Slip a piece of 14-in. cotton tubing or lacing over Amateur - EKlectrician y And Wireless Operator ae each lead and connect it to the binding posts. Fasten the fiber to the transformer by tying it with cloth tape. The proper and efficient way to fill the air gap would be to cut small pieces of transformer iron and wedge them in place in line with the other laminations. Another way is to cut pieces of the metal 134 in. long by I in. wide, and drive them in at right angles to the core iron. This latter method causes the wedge to heat up, showing there is considerable loss through eddy currents. For most experimenters the transformer will operate efficiently enough with gap left open.—O. J. HuRLBuT. One Telephone Used on Two Lines HERE it is desired to use one tele: phone on two lines so that both lines will be kept separate and yet sound ‘the rings from each line, the following method may be used. Connect an _exten- sion bell and a double-pole double-throw switch to the telephone and the lines, as shown in diagram. If one of the lines is a grounded circuit, the ground should be connected to one side of the switch and not to the telephone or t SWITCH Connections of telephone wires and bells for using one telephone on two lines EXT. BELL TELEPHONE bells; but if both are grounded circuits the common wire should be connected to the ground. In the diagram, if the switch is thrown up, the telephone is connected to the line 1 307 308 Popular Science Monthly and the bells to the line 2; if the switch is down, the telephone will be connected to the line 2 and the bells to line 1. It is best to have the bells produce a different sound on the instruments so that you may tell by the sound which is ringing. If a small nick is filed in one of the bells it will change the tone.—A. A. DAVIDSON. An Electric Lamp-Socket Lock Clamp and Seal er egepadae tungsten globes are apt to be a temptation to the petty thief. The illustration shows a new lock for pre- venting the removal of a globe from its socket. It consists of a clamping-ring that fits over the raised portion of the lower end of the socket and is held with a screw. The screw-head is provided with a three-cornered pro- jection inside of a raised ring for a key to enter in turning the screw. Through the raised portion is a hole for a bit of wire, the kind used for seals, to be inserted. The globe cannot be removed without breaking the seal and using the key. A sealed lock-clamp on an electric socket A Knob-Control for an Inductively Coupled Tuner CONVENIENT arrangement whereby an inductively coupled tuner can be operated by means of a round knob on a Manner in which the knob is attached to the shaft to operate a long slide of a tuner panel receiving set is shown in the drawing, Fig. 1. A double-grooved pulley is repre- sented at A, which is locked on the stud- bolt B. This bolt passes through the sleeve C, which is locked on the panel D. The handle E is fastened to the other end of the stud-bolt. The method of operation is shown in Fig. 2. This arrangement allows the use of a coupler which has a long slide. aR ti A SSN ———> FIG.2 The method of operation of the knob- control where the coupler has a long slide A heavy cord is fastened to the secondary coil and passes over the two pulleys E. Each end of the cord is led to a separate groove in the pulleys A. The cord can be fastened on the pulley by drilling small holes in the flange of A and tying knots securely in it. The size of pulley A is determined by the length of the slide of. the loose coupler.—D. R. SIMMons. Remover for Insulation on Electric Wires O remove, or skin the insulation from a wire, cut a V-shaped slot having curved sides in the end of a flat bar of tool steel, as shown in the detail. For practical purposes a bar of steel 3 in. long, 11% in. wide and 14 in. thick will be needed. Two holes are drilled below the apex of the slot for screw- 4, ing the cutter to the workbench. Whenan insulated wire is pressed into the slot, the sharp edges cut through to the wire and its covering is readily removed by a quick pull downward. —E. B. WILLIAMs. ee De VM A Removing the in- sulation from wires How to Make a Portable Aerial for Wireless COMPACT aerial that can be carried in the pocket may be improvised from a long steel tape measure, such as is used by surveyors or building contractors. When not in use it can be rolled up into its case and carried in the pocket. Although steel does not have the conductivity of copper, such a tape has given very good results, when strung from a tree or housetop to the receiving set. Arlington has been heard clearly in New York when this kind of an aerial was employed. ! F ] ~~ Pe How to Become a Wireless Operator VI.—Simple Adjustments and Connections By T. M. Lewis KILL in receiving, which includes both the ability to “copy’’ Morse and Continental signals rapidly and ac- curately, and facility in the adjustment of the receiving instruments, is one of the most important things for a radio-operator _todevelop. Knowledge of the transmitting A switch panel made of hard rubber or fiber is mounted to the top of the end blocks apparatus and its manipulation, as well as a clear and firm method of handling the key in sending, is of course essential; but without knowing how to adjust the receiv- ing tuners and detectors so as to get maximum strength signals with the least interference a wireless man ‘soon finds himself in trouble. The only way to gain the needful familiarity is through practice with the apparatus itself; and at the same time the student must realize how and why his instruments work. Unless it is clear to him just what effect will be pro- duced, and why, whenever he makes an adjustment or changes a setting, he will not progress very rapidly. In the January article of this series it was shown that the detector and stopping condenser previously described could be assembled with either of two types of tuning coil (the ‘‘one-slide’’ and the ‘‘two- slide” varieties) so that messages could be received from commercial and naval sta- tions hundreds of miles away. Receiving practice gained through use of receiving apparatus in the ways indicated will form a valuable foundation for further advances in the use of more complicated tuning arrangements, and the experimenter should familiarize himself with the action of the circuits shown in Fig. 3, 4 and 5 of the last article. Methods of Connecting The method of connection shown in Fig. 5 of the January article is the most effective of all the simple arrangements. It requires a tuning coil with two variable contacts or sliders, in addition to the usual detector, telephones, and stopping-con- denser. This same tuner may of course be used for tests of the single-slider ‘‘hook-. ups,” by using only one of the movable contacts; such trials will demonstrate beyond doubt the fact that, when it is properly adjusted, the two-contact arrange- ment gives louder signals with greater freedom from interference. Somewhat more skill is required to get the best results from the two-slide than from the one-slide apparatus, but the effort is more than repaid. Sliding-contact tuning coils for use im any of the circuits described may be pur- chased from the wireless supply houses, and will give reasonably good results. It is very easy to make such tuners, since all that is required is a coil about 3 in. in diameter and 8 in. in length, wound with insulated wire of about No. 22 gage and fitted with two contacts which slide along rods supported above paths from which Sa WIRE TO BE PAPER TUBE FIG.2 The twist and loop stand up from the coil and the wire is soldered to the loop the insulation has been scraped. Such instruments have been used in commercial radio-telegraphy, and were very common in the stations of eight or ten years ago. It has been found, however, that the sliding contact upon the coil itself is not particular- ly desirable, since the slider finally wears 309 310 Popular Science Monthly through the wire, and there is always difficulty in maintaining good contact. Further the slider usually short circuits several turns at its point of contact, and thus causes mistuning and loss of signal ‘strength. These disadvantages of the slid- FIG.3 D' The rotary switches mounted on the panel, one having ten and the other fifteen points ing contact, taken together with the poor circuit design often employed, have brought the direct-coupled circuit of the sort described into disrepute; there is really little choice between the direct and in-— ductively coupled receivers, however, pro- vided that both are properly built. By making the loading and transformer coils in separate units, and fitting each with switch contacts instead of sliders, it is entirely practicable to produce a receiving installation which has all the selectivity of the inductively coupled type and still avoid some of its disadvantages. Such coils are described below, and their mode of connection is shown in Fig. 7, which cor- responds to Fig. 5 of the December article. The Loading Coil This instrument is shown in Fig. 1. The basic piece is a paper tube of about 4 in. diameter and 8 in. length. Beginning about I in. from one end, No. 20 gage double silk-covered magnet-wire is wound on evenly for about 6 in., which will take 149 turns. A tap must be taken out for each of the first ten turns, and one for each tenth turn thereafter, as shown in Fig. 4. The best plan is to fasten the end of the wire, before beginning winding, through two small holes punched in the paper tube, leaving about 2 in. of wire free for the tap marked ‘'9” in Fig. 4. Then a single turn is eee on, and a small loop twisted in as shown in Fig. 2. This twist and loop stand up from the surface of the coil, and the wire leading to contact ‘‘8,” Fig. 4, is later soldered to the loop. The second turn of wire is then wound on the tube, and another twisted loop. for the 66 p99 contact “7’’ is made. Thus a twist is put in for each of the contacts, at the end of each turn, till that marked ‘‘O”’ is reached. Then ten turns are wound without a tap, the twist for ‘‘10”’ being taken out at the 19th age of the whole coil. Similarly taps for ‘‘20’’, ‘‘30’’, etc., are made at each tenth bay tenet ter. The completed coil is to be mounted between two end blocks of wood or hard rubber, A, in Fig. 1. are fastened to the inside faces of each of the end blocks, as shown in dotted lines, to keep the coil from slipping sidewise; and the whole is held together by a piece 1 in. square passing through from end to end in the center of the coil. Screws B, with washers under their heads, pass through holes bored in the end blocks and clamp the tube by threading into the ends of this central stick. As further shown in Fig. 1, a switch- panel is mounted on top of the end blocks. This should be made of hard rubber or fiber, about 14 in. thick, though hardwood ~ 34 or % in. thick will do. It is fastened to the end blocks by means of two wood-screw binding posts D, D', Fig. 1 and 3, and the screws E, Fig. 3. On it are mounted two rotary switches, one having 10 and the other 15 points, as shown in Fig. 3. Any type of switch-arm will do for these, but the easiest manipulation will be obtained if a center-knob type is used. The 10-point switch should be markec “Units” and the 15-point ‘Tens’; the i UNITS TENS ry FIG.4 The wiring diagram for the loading coil showing the turns and where they are tapped buttons are to be numbered from zero to 9 for the former and from zero to 140 in tens for the latter. The taps from the coil itself are to be connected with these switch- points by means of short soldered leads, as shown in Fig. 4. Great care must be taken to see that no short circuits are made as this wiring is put in place. The central points of the switches, i. e., their arms, have wires leading to the binding posts Three small pieces | ee Popular Science Monthly D, D*. It is best to make the switch buttons marked zero the lowest; then as the switch-arms are turned toward the upper positions, more and more turns of the coil are cut into the circuit between MW 20 20 O SECONDARY O S=O = pase pec. FIG. 5 The transformer coil wiring diagram show- ing only eight taps taken from the turns the two binding posts. As is obvious from the diagram, the “‘tens’’ switch cuts in ten turns at a time, while the “units” switch gives steps of a single turn. By various combinations of both switches, any number of turns from 1 to 149 can be had. The Transformer Coil Another coil very much like the first is now to be built. The mechanical features are exactly the same; but only 8 twisted taps are taken out from the 150 turns of No. 20-gage wire. The end of the wire is connected to a binding post F, Fig. 5, and taps at the tenth, thirtieth, fiftieth and each twentieth turn thereafter are led to the corresponding points of two nine-point switches mounted on the panei. These are marked ‘‘Coupling’’ and ‘“‘Secondary”’ re- spectively, and take the places of the 10- point and 15-point switches on the loading coil just described. Their buttons are marked 0, 10, 30, 50, and so on to 150, in steps of 20 turns, and the soldered connec- tions are made as shown in Fig. 5. The binding post F may take the place of one of the screws E in Fig. 3, and the posts G and H are located as D and D' in Fig. 1. It is to be noted that in the loading coil the adjustment of inductance may be had in single turn steps by the use of two switches, but that there are only two points of connection. In this last described coil there are three points of connection, two of which are variable in steps of 10 and 20 turns from 0 to 150. Thus the two coils, while superficially alike, may be used for very different purposes. 311 Switches It is possible to buy lever-switches from the various supply houses, but usually the type with the knob at the outer end of the switch-arm is furnished. This is not nearly so convenient for tuning as the kind with central-knob shown.in Fig. I, 3 and 6, since considerably greater movement of the hand must be made in order to accom- plish a given adjustment. Central-knob switches are not difficult to make; a simple and effective design is shown in Fig. 6. The switch-points J may be of any sort whatever; most supply houses will sell these for one or two cents apiece. The switch-arm K is cut out of thin spring- brass, and is formed of two pieces, each having one end punched to fit over the machine-screw O and the other end bent down to make smooth contact with the buttons J. The arms are fastened to the turned hard rubber knob L by means of the brad or escutcheon pin M, and are further clamped by the two nuts N, N’. The central machine-screw O passes through the switch-panel Q within a short sleeve P and through two washers shown but not lettered. Two additional nuts N"™ and N™ are clamped on the, inside, just enough play being allowed for free turning when the arm K bears upon the contact points. Connection to the arm is made through the spiral R, the free end of which is soldered to the screw O. Soldered con- nection is made to the switch-points at J. Setting Up the Receiver The loading coil and the transformer coil as described above are to be combined with a detector, telephone set and stopping- —* FIG.6 Diagram of the central knob used on switches. It is very effective and not difficult to make condenser as shown in Fig. 7. The antenna circuit passes through the loading coil from D to D' and thence to binding post G of the transformer coil. This leads to the “‘coupling’’ switch, and the circuit runs from there through whatever part of the coil is cut in, and out to ground through 312 Popular Science Monthly binding post F. The secondary circuit includes that part of the transformer coil cut in by the ‘‘secondary”’ switch, and runs from binding post H through the detector and stopping-condenser to the ground binding post F. The telephones are connected across the stopping-condenser. A crystal detector and stopping-con- denser suitable for this use were described in the PopuLAR SCIENCE MONTHLY for November, 1916, in the third article of this series. The proper sort of telephones to use was also discussed in that article. A test-buzzer arrangement for adjustment of the detector was explained in the December article, and should be combined with the outfit of Fig. 7 in order to make the adjust- ment easier and mire positive. Tuning The circuits of Fig. 7, with the apparatus described, will give excellent results in receiving from the commercial and naval spark stations, if used with an \V antenna of from 150 to 250 ft. LOADING COIL TRANSFORMER COIL FIG.7 These circuits with the apparatus de- scribed give excellent results in receiving length. For shorter wavelengths than 500 meters the antenna used should be somewhat shorter, and for waves longer than 2500 meters (that on which time signals are sent) it is advantageous to use still longer wires. It is not neces- sary to erect multiple wire aerials for receiving, nor is great height essential. A 200-ft. single wire, of No. 10 gage copper, or even galvanized iron, swung horizontally between two 50-ft. masts or trees, will prove entirely satisfactory for most pur- poses. When it is desired to receive the short waves from amateur stations, which are restricted by law to wavelengths under 200 meters, a wire not much over 70 ft. in length should be used. In attempting to “‘pick-up”’ signals with the outfit of Fig. 7, the best plan is to set the: ‘“‘units’’ switch on 5, the ‘‘coupling”’ switch on about 30, and then to vary simultaneously the ‘‘tens’’ and the ‘‘second- — ary” switches. As the turns on the loading coil are increased in number, those of the secondary should also be increased. When signals are heard, the best point of the secondary is selected, and the loading coil and coupling switches adjusted to give the loudest responses. One must of course be careful that his detector is adjusted proper- ly before starting to tune; for this purpose — the test-buzzer is a great time-saver. It will be noted that more turns of the loading coil and of the secondary are needed for long wavelengths than for short ones, and that when the number of “‘coupling”’ turns is reduced, the number of turns in the loading coil must be proportionally increased. This is because the loading coil and the coupling turns in series form a primary circuit, whose effective length must be adjusted for the various wavelengths in the manner described last month. It will also be noted that all stations which have the same wavelength will ‘‘come in” best with approximately the same settings, and that the wavelength of any station may be estimated roughly by considering the num- ber of turns in the loading and coupling coils which give the strongest signal from it. A thing which is very important in the operation of this tuner, however, is not likely to be evident from the first tests made upon it. That is the relation between the sharpness of tuning and the number of turns on the coupling part of the trans- former coil. Careful observation will bring out that when the number of turns on the coupling section is reduced, and the loading coil correspondingly in- creased to the tuning point, better selectivi- ty is obtained. Usually there is a best value of the coupling turns for every station or wavelength, and its use requires the proper corresponding settings of the loading coil and secondary switches. Often when there is interference it is best to use still fewer turns of the coupling section, corre- spondingly increasing the loading coil, so as to get sharper tuning in spite of a weakened signal. The judicious selection of values for these three coil sections (primary, coupling and secondary), and the proper balancing of signal strength against sharpness of tuning, is one of the items which is most important in commer- cial radio-telegraphy. Many operators fail to get the most out of their receivers merely because they fail to pick out the best ne ee a ee a ye Oe ee ee: ee os © il oe 2: : a i La Se aie iia talinal a or a a Popular Science Monthly adjustments, or because they do not retune primary or secondary circuits after chang- ing coupling values. Practice with the apparatus of Fig. 7 should make the desirability of correct tuning evident to every experimenter. In the next article of this series there will be discussed the secondary variable con- denser. When properly used, this instru- ment is of great value in increasing sharpness of tuning. An Easily Made Adjustable Telephone Condenser CONDENSER which has the advan- tage of easy variability and inter- change of units may be made as follows: Secure a number of burned-out cartridge fuses and take the caps off very carefully, being careful not to bruise them. Clean out the insides thoroughly, and open the holes in the caps so that you may solder the internal leads to them. Cut some tinfoil strips 134 in. wide and of length to be determined by the capacity of condenser-units you desire. Prepare also some strips of paraffin-impregnated paper about )% in. wider than the foil and about 1 in. longer. Lay down the paper on a smooth surface, and on it place a strip of foil (see Fig. 2) with a piece of stranded copper wire attached to the end for connec- tion. Put a second strip of paper on top of the foil, and then another strip of foil. Fasten a wire terminal to this second foil piece, taking it out in the other direction _) Natl far] fat] (fy) (Ps"] fave EF es Aled fll elf b wif S17. sf | OOD Mtn, “OfWrn, bm 40 *]. sit FIG.1 PAPER 1] — as = = —s = _LENGTH ACCORDING-10 CAPACITY = _ recat —— ra : A — STRANDED COPPER WIRE TINFOIL FIG.2 Above: The cartridge holder brass strip. Be- low: Strips of tinfoil on the paper before rolling as shown. Now roll up the whole four strips as tight as possibleand tie the roll with thread. Soak the rolled unit in melted paraffin until no air bubbles can be seen. Next insert each rolled condenser into a fuse-tube, with one of the connecting wires 313 projecting out of each end. Run these wires through the holes in the caps, and solder. This completes the condenser- units. The capacity, or the number of square inches of tinfoil, should be marked. A holder for the cartridges should be ~ —| Uy Ss \ SS TAA AX FIG.3 The cartridges filled with the rolls of tin- foil and mounted on the holder or base made by bending and cutting two strips of 1/32-in. spring brass or copper, about No. 20 gage, each of which is 534 in. long and 14 in. wide, as shown in Fig. 1 and 3. Additional dimensions and the method of mounting are shown in the drawings. How to Keep the Telephones from Humming MATEURS who have alternating cur- rent in their homes and a droplight near the instruments are usually bothered by a 60-cycle buzz in the telephones. This is very unpleasant when receiving weak signals from a distant station. It will be noticed that by putting the hand near the lamp-cord the sound of the buzz is increas- ed, but when the hand is placed around the cord the sound ceases entirely. Evidently the body acts as a conductor between the line and the ground. The fol- lowing remedy has proved very satisfactory. Wind one or two layers of No. 18 or No. 24 cotton-covered wire around the lamp-cord for about 4 or 5 in., keeping them as close and compact as possible. The other end of the wire is then connected to the instrument ground-binding post or some other ground connection as near to the instrument as possible. A telephone or other condenser of 1 or 2 M. F. connected in series with the wire and the ground also gives good results, and if desired, two tele- phone condensers may be connected in multiple, for the more capacity the better. Do not let the cotton-covered wire touch the socket, as there may be something wrong inside. This method is not good for preventing a buzz caused by arc-lights or other outside circuit—D. BROWNE. 314 An Electric Gas, Lighter for the Kitchen Range bike illustration shows the necessary parts and a wiring diagram for making an electric lighter for the gas range. A %%-in. spark coil A is con- Spark coil and its connection for lighting the gas by electricity nected in line with the battery B and to an old telephone hook C, for the primary coil; the secondary is connected to a piece of fiber tube D, which is 4 in. inside diameter with a piece of 14-in. brass or iron rod driven into it, allowing one end to extend 4 in. A heavy insulated flexible wire is soldered to the other end and the space filled with paraffin or other insulating material. If this wire is properly fastened to the end of the tube, the handle piece thus formed can be suspended from the telephone hook when not in use. The other end of the secondary wire E is fastened or grounded to any metal part of the stove and a ¥%-in. gap is made at F on the coil. When the fiber tube is taken from the hook it will close the primary circuit and a spark will jump the gap F, but when the end of the rod is placed near the burner on the stove a spark will issue therefrom and the gas will be lighted. The whole outfit can be inclosed in a neat box with the telephone hook extending, the box being placed on the wall near the stove. A Reliable Radiation and Tuning Indicator HIS arrangement acts as a radiation indicator and serves the same pur- pose as the hot wire meter, except that it is less delicate. It does not interfere with the oscillations, and can be left in circuit continuously. The connections are shown in the drawing. The coil is - constructed like a helix, and contains about a dozen turns of No. 8 wire wound on a form 3 in. in diameter and spaced Yin. apart. A movable contact is pro- vided as shown. The lamp used is a Popular Science Monthly small four or six-volt carbon filament bulb, which may be obtained from any supply house. When the transmitter is in operation the lamp lights up. The coil is connected in shunt around six or more feet of the ground wire from the trans- mitter. The proper length must be de- termined by experiment. Only a small part of the high frequency current is passed through the coil by this arrange- ment. To find the adjustment for maximum radiation at a desired wavelength, place the slides of the in- : dicator coil so that all the turns are in circuit and adjust the antenna circuit inductance until the lamp lights up the highest. Now de- crease the number of turns on the indi- cator coil, thus de- creasing the bril- Substitute for a hot wire meter liancy of the lamp, = and re-adjust the » transmitter circuits for the brightest light. Continue this process until the lamp lights up brilliantly with the least possible number of turns on the indi- cator coil. The transmitting station will then have a maximum radiation for the given wavelength. This will be welcomed by those wire- less amateurs who could not make, or who had not the means to purchase a hot-wire meter. An Electric Gas Lighter Operated with a Push-Button ~ AVING one of the single pull chain electric gas lighters I decided to change it into one that would work with An electro-magnet to operate the con- tact points for making spark on gas tip a push-button, and I accomplish my pur- pose by making the simple arrangement illustrated. The single chain type, as 1s a ee a? RTL eT Ne aS ee eS Popular Seience Monthly 315 well known, utilizes a ratchet arrange- ment to turn on and off the gas. The first pull turns it on and lights it, the second extinguishes the light by shut- ting off the gas. Instead of actuating it by hand an electromagnet was made and mounted on the gas jet asshown. This magnet was wound on a brass tube in. in diameter and 2in. long. Six layers of No. 24 gage wire were wound onit. The armature is a length of %-in. soft iron rod, to one end of which a disk 34 in. in diameter is fastened by means of a machine screw. The chain arm was cut off as at A. The regular gas lighting equipment ‘consisting of battery and kicking coil was used. The battery consisted of four dry cells and the kicking coil was made from 1 lb. of No. 22-gage soft iron wire 6 in. long and covered with No. 18 insulated wire. The coil wire is made into a compact bundle and carefully in- sulated. Two heads are cut from 44-in. stock. The winding consisted of 6 layers of No. 18-gage wire—about 1% Ib. being required. These were connected in series to the break mounted on the gas jet. Shunted across the battery was the solenoid and a push button. The operation is very simple; pushing the button energizes the magnet, draw- ing the core in, which pushes the contact arm over. The ratchet turns on the gas and as the contact arm passes the contact on the stem of the fixture a spark is emitted when the circuit is broken, due to the high inductance of the kicking coil. When the button is re- leased the arm flies back and the gas remains lit. A second push on the button will put the light out. This apparatus can be installed at much less cost than the usual automatic lighters, and it will be found to work equally as satisfactorily.—Tuos. W. BENSON. Measurement Units of Wireless Telegraph Inductance IRELESS telegraph inductances are usually measured in either millihenrys, microhenrys or centimeters. Each of these units is a subdivision of the fundamental practical unit which is named in honor of the great electrician Henry. One millihenry is equal to one thousand microhenrys, and one micro- henry equals one thousand centimeters of inductance. An Electric Circuit for a Freezing Alarm ITH the simple device illustrated an alarm will be given when the temperature reaches the freezing point. . The expansion caused by the freezing of the water makes the electrical contact A block of wood 4 in. long, 3 in. wide and 2 in. thick makes the base A. A small hollow rubber ball B is glued in block A with about one-third of the top cut off. A very thin strip of sheet copper D is placed against side of ball B and fastened to base A with screw G. Another piece of thin copper E is placed on the base by means of a screw F. This piece of copper should come within 1/32 in. of touching the copper D. The ball B is then filled with water, to C. When the temperature becomes freezing a thin coat of ice freezes over water C in ball B, causing the rubber ball to expand and push copper D out against copper E which closes the circuit WM. HARRIER. Makeshift Motor Starting Box for Burned-Out Rheostat NE of the questions that is often put to applicants for commercial radio licenses is: ‘‘In case your motor starting rheostat should be damaged beyond repair, what would you use as a substitute?’ The answer to the question usually is: ‘I would use an —— = Iron plates suspended in an acidulated salt water solution for a starting box iron pail filled with a solution of salt or slightly acidulated water and an iron rod or plate.” This substitute is one that can be applied very often in repair shops or 316 Popular Science Monthly factories, when the starting rheostat gets out of order. Fora 100 h. p. motor, a water rheostat of the dimensions given below will be quite satisfactory. Assuming that the voltage is I10, so that the amperes on full load amount to 680, a fairly large-sized wooden cask is necessary, to allow for a proper dissemination of the heat which is produced by the heavy current. Ac- cordingly, a large wooden cask is filled with slightly acidulated water—sulphur- ic will do—and an iron plate having four square feet of exposed surface bolted to one side of the cask in the solution. Another plate of the same dimensions is lowered into the water with a heavy, flexible, insulated cable. When it is completely submerged, a short circuiting switch is thrown in. Hairspring of a Watch as a Detector-Point Support HE illustration shows a _ home- made detector which may be help- ful to those who do not need to construct a more elaborate instrument. The hairspring of an old watch pro- vides support for the point, and is an effective shock absorber. It is held by a drop of solder to the adjustment arm, which is bent at right angles after insert- ing it in its binding-post support. A one-inch length of annunciator wire is sharpened to a point for the crystal contact. Wind a few of the innermost turns of the spring around it, as shown in the drawing, and fasten with a well- A length of wire pointed and supported by the hairspring for a crystal contact placed drop of solder to avoid loose contact. If the conventional cup-type mineral holder is not to be had, a good clamp can be made very easily by bending up one side of a small piece of sheet brass as shown. Solder a nut taking an 8/32 in. screw directly opposite, and grip the crystal by tightening the screw on it. Making a Miniature Light to Attach to a Book Wire Insulated tron ANY a CTC) es sum- mer evening would be more enjoy- able if one could sit on the veranda and read with iy Soring brass only light enough to Look cover illuminate Saha eke's the book. iny electric lig or a attaching to book covers The same 1S true in win- ter, when there is an open fireplace. A simple book-light can be made by bending a strip of brass, 4% in. thick and 1 in. wide, as shown in the diagram. Bore a hole large enough to receive a miniature lamp, which should fit snugly. Attach two thin strips of brass (1% in. wide), to the other end of the first piece of brass to act as a spring, which can be slipped over the cover of the book. The wire connections are shown in the illustration.—Wwa. E. FINKERNAGEL. An Airtight Quenched Spark-Gap \ A JHETHER or not quenched spark- gaps should be made completely airtight has often been a subject of dispute. The Telefunken gaps are usually fitted with plain mica separating- rings, and no great pains are taken to exclude air from the space between the sparking surfaces. omer In spite of this, the : Telefunken trans- mitters as a rule op- erate efficiently and } with uniform, clear spark-tones. The effectiveness with which a quenched- gap prevents “‘back- firing’ depends to a large extent upon [ the condition of the parallel sparking- surfaces. If these are perfectly smooth and very slightly oxidized, the operation of the apparatus is usually most satisfactory. How long the plates will remain in good condition depends upon the material from which Construction of De Forest’s air-tight gap Bese ee Popular Science Monthly the sparking-surfaces are made, and also upon the freedom with which air is admitted to the gap. Copper plates which are not provided with airtight gaskets soon become so thickly covered with oxides or compounds including nitrogen that gap action grows irregular; it is therefore desirable to exclude air from such instruments. When silver surfaces are used, the oxidization is not so rapid, and it is not necessary to take such precautions. The drawing, which is taken from 1916 patent No. 1,171,598, issued to L. De- Forest, shows a method which has been found very useful for making quenched- gaps airtight. The structure comprises the usual plates 4, piled upon each other and clamped by means of screw 16 into containing frame 13. Electrical con- nection is made through the wires 18 which are connected to the clamping- heads 15. The novelty claimed for the present patent consists in the use, between the individual plates of the quenched-gap, of washers consisting of soft compressible varnished or impreg- nated fabric. When this material is clamped between the plates it effectually prevents the entrance of air, and so limits the formation of oxides upon the surfaces of the plates. Further air- tightness may be secured by filling the space between the peripheral rims of the plates with a compound such as paraffin or beeswax, as shown at Io. In building quenched-gaps of airtight construction, care must be taken that the normal cooling of the gap is not greatly reduced by prevention of ventilation. Also, in using compressible gaskets, the screw 16 must be carefully adjusted in order that the plates be not forced into accidental contact. If the necessary precautions are taken to insure per- manence of separation of the plates, an airtight gap is likely to require cleaning much less frequently than one in which oxidization is permitted to progress freely. Such an airtight quenched spark gap is especially useful on ships at sea and at any land stations which would be effected by the rapid action of salt air upon the material of the gap where it is heated by the spark. In such a case a gap of this type will not only work more efficiently but will wear considerably longer. 317 Spark Sender for Sustained Wireless Waves HE drawing shows a transmitter described in U.S. Patent 1,166,892, issued in 1916 to R. A. Fessenden. The high-voltage direct current dynamo A charges the outer plates of the condenser B, through the resistance or impedance C. The condenser discharges through the oscillatory circuit formed by the adjustable inductances in wires D and E, and the rotating spark-gap F. This gap consists of a stationary elec- Coa mS. Lays E ae Se Fessenden’s method for coupling the os- cillatory circuit with that of the aerial trode placed near to a disk which revolves at high speeds; the inventor suggests that the relative movement of the two sparking points may be as high as 12 miles a minute. The construction may involve two rotating disks, or some other mechanical form which will operate at very great speeds and so prevent the formation of any ark in the gap. In such an arrangement, the specification states, continuous and regular discharges are produced and sustained, or practically sustained waves are generated at high efficiency. The mode of coupling to the antenna- to-ground circuit through the internal plates G, H of the sending condenser possesses some interest. This is equiva- lent in many ways to the static couple transmitters which have recently been tried in connection with various types of ark and spark generators. In order to secure good transfer of oscillating current energy from closed to open circuit it is necessary that the radiating circuit be in tune with the local circuit formed by the plates of B and the inductance in the lead wires D, E. This is accomplished by the usual insertion of variable inductance and capacity in the antenna circuit. 318 Strain Insulator Construction for Aerial Lines HE accompanying illustrations show a method of constructing strain insu- lators which answer the purpose admirably. Procure, for each insulator required, a piece of wood 114 or 2 ft. long and 2 in. square. Chuck each piece in a wood lathe and turn them to 2 in. in diameter. At intervals of 3 in., turn V-shaped grooves A Fig. 1, 1% in. deep. Remove from the lathe and drill %-in. holes B in the ends and trim them flat with a draw shave as shown. Soak the wood for at least an hour in a molten mixture of equal parts paraffin and resin, to which has been added enough black asphalt to color. Allow the mixture to penetrate the wood as far as possible. Cut circles 1214 in. in diameter from card- board. Holes C Fig. 2, 134 in. in diameter are cut out, and one-third of the remaining surface, represented by the dotted line, is cut away. These cardboard segments are An insulator made of wood and cardboard disks then thoroughly soaked in paraffin and resin then boiled in the above mixture until com- pletely impregnated. Coil them around the grooves, allowing the edges to overlap ¥ in., and fasten with thread as shown in Fig. 3. The completed insulator is now immersed in the insulating mixture until all cracks have been filled and air bubbles Popular Science Monthly expelled, then removed and allowed to cool. It is practically impossible for a film of moisture to cover this insulator, even during damp weather.—H. W. OFrFIns. Making a Tuning Coil Slider from a Fountain Pen Clip VERY good tuning coil slider can be made from a fountain pen clip and a small block of wood with a hole in the lower DIATOLSUGNUUEUAUUUOAELOPEDETHOEUUTOGOEQUOAULOFOETEGEEEEEOGUUENOESEEEROCOUEEOUESEEOUUGUUUGLAUTHLIUHT UAH A slider, made from simple materials, which passes easily over the wires on a tuning coil part of it for the slider rod. The sides A of the clip B should be bent into a square form so that they will fit around the block as shown at C. Tack the clip on the block, making sure that the bottom of the clip will touch the slider rod when it is mounted on the tuning coil. This is very important because the contact is made at this place. The arm with the knob on the end should be bent down until it touches the coil. A knob may be fastened on top of the block for convenience.—CLARENCE HUNT. Detecting Defects in Castings with Magnets ETECTING the presence of internal defects in iron and steel castings is accomplished by a current which is supplied from a small alternator to the primary winding of an induction coil, and which induces in the secondary winding a current which is passed through coils of two horse- shoe magnets, mounted at a fixed distance apart and movable to and fro over the surface of the casting. The fields of both magnets will be affected uniformly if the structure is homogeneous. Defects, how- ever, will disturb the lines of force from the nearest magnet. In a vibrating sounder, connected with a secondary coil on the magnet, the tone produced will differ in pitch from that given out from the cor- responding sounder connected with the - other magnet. Amplification of sound is secured by microphone attachments’ en- abling the observer, by means of telephone receivers, to detect the locality of hidden flaws as the magnets are moved to and fro over the castings. 0 What Radio Readers Want to Know Interesting and Instructive Questions and Answers Loading Coil for an Aerial to Receive on Long Waves W. L., Secaucus, N. J., writes: Q.1. I have an aerial 75 ft. in length, 18 ft. in height at one end and 25 ft. in height at the other end. Please state the natural wavelength. It has _ four wires spaced two feet apart. _ A.1. The wavelength of this aerial is approxi- mately 165 meters. Q. 2. Is it possible to load this antenna to the wavelength of 6,000 meters? A. 2. For receiving purposes it is practical. _ Q.3. Please give the necessary dimensions for a loading coil for this aerial. A. 3. Wind upa cardboard tube 6 in. in diameter, _ 24 in. in length, with No. 24 S. S. C. wire, and bring taps from the winding every inch. .You will then _ have no difficulty in boosting the wavelength of _ this antenna to 6,000 meters. Inductively Coupled Tuner of 11,000 Meters M. D., Newark, N.J., inquires: Q.1. Please give me the dimensions for an inductively coupled receiving tuner to be adjustable to a wavelength of 11,000 meters. How many taps are required on each winding? A.1. The secondary winding of this tuner may be 15 in. in length, 7 in. in diameter, wound closely with No. 32 wire; the corresponding primary _ winding may be 7}4 in. in diameter, 15 in. in length, _ wound closely with No. 24 S.S.C. wire. The turns __ of the secondary winding should be equally divided _ between the contact points of a ten point switch, while those of the primary winding may be wired either by means of two multipoint switches or by a sliding contact. For this equipment you should have two variable condensers of .oo1 microfarads capac- ity, one being placed in shunt with the primary winding on the receiving tuner and the second in shunt to the secondary winding. Induction Interference from a Neighboring Motor C. V. H., Kinsley, Kansas, writes: Q. 1. We have been using a wireless set for the reception of time signals for over a year. During this period we have experienced no interference of _ any sort, but quite recently a garage about one block away installed a motor generator for charging stordge batteries. When the batteries are being charged the induction is so bad we are unable to read asignal. The difficulty does not seem to lie with the motor generator, for the interfering noises are only heard when the batteries are connected thereto. Can you advise a remedy for our troubles? A. 1. One thing is certain, when the motor gen- erator is connected to the storage batteries there must be a fluctuation of the line current, and con- sequently it sets up inductive noises in your receiver. It may be that the commutator of the motor generator set sparks badly. A similar case of induction was eliminated in the following manner: The power leads from the motor generator to the storage battery were placed in an iron conduit and the iron conduit firmly connected to earth. In addition two condensers of two microfarads capacity each were connected in series and earthed at the center point. The other terminals were shunted across the storage battery. Connections for a Three Slide Tuner with Other Apparatus F. H. M., Richmond Hill, N. Y., inquires: Q. 1. When do Sayville, Arlington, Tuckerton, and the Brooklyn Navy AERIAL Yard send out messages, SZ and what is their wave- length? A. 1. The wavelength LOADING COL © Of Sayville is 9,400 meters; re Arlington 2,500 meters for the spark set and 7,000 meters for the arc set; DET. = yy 71 vc. i } HI = 3 SLIDE sq TUNER PHONES @ Diagram of connections for a three slide tuner, galena detector, loading coil, fixed condenser and variable condenser Tuckerton 7,400 meters; Brooklyn Navy Yard 600 and 1,000 meters. Sayville and Tuckerton may be heard any evening between the hours of seven and twelve Pp. M. eastern standard time, while Arlington may be heard at I2 noon and I0 P.M. eastern standard time, using the spark set at the wave of 2,500 meters. The Brooklyn Navy Yard com- municates at irregular intervals with other Naval stations throughout the entire day. Q. 2. Please give a diagram of connections for the following apparatus: Three slide tuner, galena detector, loading coil, fixed condenser, and variable condenser. A. 2. Diagram of connections is shown above. 319 320 Polarized Relay as Interrupter H. B. R., Monticello, Ga., inquires: Q. 1. Please advise if an electro magnetic polarized relay will work successfully on 110 volt 60 cycle alternating current as a vibrator for an induc- tion coil in the following manner: I propose to use two armatures each having a contact which makes connection with a stationary contact. Do you consider this feasible? A. 1. Itis believed that you will find it extremely difficult to adjust both contacts to interrupt the circuit of each coil if they are mounted on a single armature. However, by the use of separate arma- tures for each set of contacts the proposition is more feasible. Several experimenters within our knowl- edge have tried out the arrangement you suggest and have reported results considerably inferior to the ordinary induction coil vibrator. Receiving on the Static-Coupled Tuner J. M. S., Jr., New Castle Pa., writes: Q. 1. Referring to the static coupled receiving set described on page 306 of the February issue of your magazine, what should be the dimensions of the coils L-1, L-2, and L-3, to make an equipment adjustable to 5,000 meters, and to be used in connec- tion with an aerial 175 feet in length, 50 feet in height, composed of a single wire. A. 1. The fundamental wavelength of your aerial is about 350 meters and all the inductance for the antenna circuit may be included in the coil L-2. Here a coil 3} in. in diameter, 10 in. in length, wound with No. 26 S.S.C. wire will permit the desired value of wavelength. The coil L—2 should if possible have about the same dimensions. It can of course be made smaller, and a portion of the in- ductance included at the point L-1, but we see no reason for splitting it in this manner. Q. 2. Is acrystaloid detector as Nenestion 5 as any crystal or electrolytic detector on the market? A. 2. Many experimenters report better results from it than with the electrolytic. For the best results the stopping condenser of the usual circuit should be one of variable capacity and possesses values up to or beyond 0.005 microfarads. Q. 3. How shall I connect a tikker in the statically coupled receiving set? A. 3. Connect it in the circuit at the same point as the crystal detector D. The condenser C—2 should then have rather large values of capacity, as much as .05 or 0.1 microfarads. Q. 4. What wavelength does Arlington use with the undamped wave transmitter, and should I be able to hear the signals of the statically coupled receiving set and a tikker. A. 4. By careful adjustment of the circuits to resonance with the wavelength of 7,000 meters, you should be enabled to receive the signals in your home town, but the dimensions for the coils which we have given will not permit this circuit to respond to the wavelength of 7,000 meters. Increased values of inductance must be added at the coil L-1. We would advise a loading coil of No. 24 wire at L-1 Popular Science Monthly approximately 8 in. in length by 3 in. in diameter fitted with a multipoint switch having taps about every half inch. You would obtain better results in the reception of signals from this station by using some form of the oscillating vacuum valve. Ground Connections P. L. K., Somerville, Mass., inquires: Q. 1. What effect has a long earth wire on the range of a radio set? Does it decrease the range? Does it increase the wavelength? A. 1. The earth lead is a part of the open circuit oscillator and consequently an increase in length of it increases the effective wavelength of the entire system. It is considered preferable in all radio installations, particularly as far as the transmitting apparatus is concerned, to make the earth lead as short as possible, otherwise the range of the appar- atus will be seriously decreased. Q. 2. I have an inverted “L”’ aerial 85 feet in length, 30 feet in height. The ground wire is 110 feet in length. Do you consider my ground wire abnormally long in proportion to the aerial? A. 2. For transmitting purposes your earth wire is too long, but for receiving purposes the length is not so serious. Q. 3. What is the natural icing. of my aerial? A. 3. About 300 meters. Q. 4. How may I reduce the wavelength? A. 4. By means of a series condenser or by decrease in the length of the earth lead. It is con- sidered sufficient for receiving apparatus to connect — the earth wire to water pipes inside the house. Sending Condenser G. D., Ligonier, Ind., writes: Q. 1. I calculate that in order to obtain a capacity of .o08 microfarads, which I am told isthe maximum value that can be used at the wavelength of 200 meters, I will require 25 plates of glass 3132 in. in thickness covered on each side with tinfoil 6 in. by 8 in. Is this correct? I fear that a single bank of these plates will not be able to withstand the voltage of the transformer. Consequently would it be proper to use two banks of 25 plates each connected Furthermore, would this reduce the in series? liability of puncture? A. 1. Each plate of your condenser will have an approximate capacity of .00066 microfarads. Twelve plates connected in parallel will give you a value of .008 microfarads. Therefore a 48-plate condenser, 24 plates in each bank and the two banks connected in series, will give you the required value of capacity. The placing of two banks in series reduces the potential on the plates to one-half the value of a parallel connection. Q. 2. Can you suggest any method by which the plates can be coated to prevent brush discharge without immersing them in oil? A. 2. You might cover the plates with a good grade of beeswax or paraffin wax, but the best method of course is to immerse them in oil. Hudson Maxim on the Popular Science Monthly —o — — From the Woolf portrait of Mr. Hudson Maxim, the famous inventor ——--———-—— {NRRATEEERERADRHGRSHERGEARGEUBERROGERGENDGRDANINONBGBHGAAINIGIGH “The Poputar Science Monruty makes useful scientific knowledge inter- esting. The-newsiness of many of its features, the dashes of mechanistic adventure, the science touches of personal interest, make the publication, to my mind, of most exceptional value to the young men of this scientific and utilitarian age where every man must be a mechanic—where honor is earned and wealth and position attained with work-tired brain and grimy hand. The Poputar Science Monrtuty is an especially good self-helper.”’ Saving Valuables in a Shipwreck What would happen if a ship equipped with the floating safes should founder in a heavy sea? Water would enter the shaft which holds the safes and would wash them overboard, where they would float until picked up by a passing ship. In this way the money, jewelry and other valuables of the passengers as well as the registered mail would be saved. At the right is a cross-sectional view of the ship showing the floating safes in position, one for each deck Py — so ee STSlololoicsicleolsr aie Popular Science Monthly 239 Fourth Avenue, New York City Vol. 90 No. 3 March, 1917 $1.50 Annually Floating Safes for — Ocean Liners When the ship sinks, the safes, containing VERY ship that goes down is to some ex- tent a treasure ship. © Her purser is in charge of much money, and her passengers carry valu- ables. Fortunes have been lost in trying to raise sunken treasure, but not until Menotte Nanni appeared on the scene did any one think of preventing the treasure from sinking, whatever hap- Why bother about ways to recover sunken treasure when a non- sinkable purser’s safe would prevent the sinking? Whena steamer passenger sees his jewelry stored away in the ship’s safe he doesn’t know pened to the ship. whether it is ae 2 FE The inventor in his floating safe, on his way to the bottom of Lake Michigan in atest ample registered mail, mail and valuables, rise to the surface space for gold bul- lion, and valuables owned by the passengers. Nanni plans to install several of his floating safes in a large, vertical cylindrical steel casing placed in a well amid- ships, the top of the well being flush with the upper deck and covered with a loose-fitting, easily-re- storage moved cap. The safes are placed one on top of another, the first, ‘ class passengers each having a safe for their valuables. two lower safes serve as a repository for registered mail and for the most precious part of the ship’s cargo. second and third The Ready ac- cess is gained going to a fF salt water [Bee grave or not. me Inspired by the know- ledge of the lack of pre- ventative measures of this kind, Menotti Nanni has devised a non-sinkable vault which is not only large enough ‘to hold the ’ purser’ssafe, to the safes through doors pro- vided in both the outer and inner casings at the various decks. Thus the firstclass passengers, for instance, could place their valua- bles in the safe at night and remove them in the but which also provides Testing the fire resisting qualities of the safes. The boat was set on fire, after which it sank. The vaults floated to safety 323 morning. Of course there 324 would be a guard in charge of each safe. If a ship equipped with such a system of ’ floating safes should sink, the cover of the — well ‘would float off, thewaterwould enter the steel casing and force the safes to rise to the surface. Once on - the surface the safes bob about, to be eventually picked up by a passing craft. The inventor has also provided — for hermetically - sealed floats to be placed at the extreme bottom of the well under the last safe. Attached to this float is a cable which serves to indicate the position and identity of the ship. It is said that the value of cargos araalls lost on the British coast in time of peace is $45,000,000. Of course the loss has in- creased with the war. The Merida, sunk in collision with the Admiral Farragut, in IQII, sixty-five miles east of Cape Charles, in three hundred feet of water, had about $200,000 in valuables in the purser’s safe. The Oceana, sunk off Beachy Head, in 1912, had on board $5,000,000 in gold and silver. The Lusitania had about $1,000,000 in gold and jewelry and several millions in securi- ties aboard. The Jslander, sunk near Juneau, Alaska, had $2,000,000 worth of Klondike gold aboard. The Pawabiac, sunk in Lake Huron, had $800,000 in treasure. The General Grant, wrecked on the Auckland Islands, in 1866, in eighty feet of water, carried $15,000,000 in gold bars and bullion. The flagship Florentia, lost in Tobermory Bay off the west coast of Scotland, also carried $15,000,000. Then, remember the fleet of seventeen Spanish galleons with an accumulated treasure of $140,000,000, which was sunk in Vigo Bay, Spain. Six of the galleons, being in shallow water, were later raised, and about $20,000,000 recovered. But the others, containing $120,000,000, still rest at the bottom of Vigo Bay. Ship in the act of sinking, showing two of the safes which have floated immediately to the surface Popular Science M onthly Delivering Orders to Conductors and Engineers on Speeding Trains __ DEVICE for delivering messages and orders to trainmen when the train is trav re full speed has been invented by Edward Y. ‘O'Con- nor and Carl N. McCaslin of Earl Park, Indiana. The station master simp- ly places the mes- sages in the device and holds it so that the conductor and engineer can catch them as the train‘rushes by. This i is an improvement over present methods, since it eliminates a stop at each station where orders are to be given. The device is of wood and conéists of three forks with clips or leaf springs attach- ed to them. These clips serve as fasten- ing points for the cord upon which the messages are hung. The cord i is thus held firmly in place. Two messages can be delivered at the same time, one to the engineer and the other to the conductor, by holding the device so that the engineer may snatch his message and then reversing the sare so the conductor may get his. The device is of wood and consists Gk three forks with clips on which the message is hung ] The editor of the POPULAR SCIENCE MONTHLY wants to hear from readers who. have interesting photographs and interesting articles to sell. curiosities, queer ways of using old devices—all these make good pictures. contributions are paid for promptly and liberally. New inventions, natural Accepted But readers must understand that only unpublished contributions offered exclusively to the POPULAR SCIENCE MONTHLY are desired. be eee Minti > a : © Underwood and Underwood Bridgeport school children going through a tooth-brush drill. Thousands of school children and adults in other cities are now given a regular drill in the care of their teeth The Tooth-Brush Drill Has Become a Part of the School Course ECAYED teeth are causing more harm to the human race than alcohol. Dr. Alfred C. Fones, of Bridgeport, Conn., says that approximately ninety-five millions of persons in the United States havedecayed teeth. Dentistry’s next great step, in his opinion, is to wipe out or prevent tooth decay by a systematic campaign of educa- tion on the care of the teeth among school children. How shall this be done? Bridgeport’s plan has attracted wide attention already. Every child in that city submits to a thorough examina- tion of the mouth and is given free treatment. This type of clinic costs about eighty cents per child per year. The city assumes one half the respon- sibility in educating and helping the children to preserve their teeth. The other half, which is placed on the child and its parents, con- sists in providing proper food and in caring for the mouth. Decayed teeth are due to the action of acids on the teeth, followed by the work of micro-organisms flourishing in the remains of food. To combat decay the surface of the teeth must be kept absolutely clean and free from deposits and accretions. power. The scissors-grinding machine run by dog Nothing less than a full day’s work with a half hour’s sleep at noon satisfies Rover Operating a Scissors Sharpener by Dog-Power HE itinerant tradesman, umbrella mender and scissors sharpener are familiar figures in the suburbs and on the outskirts of large cities, where they break the silence and the monotony of the hours with their horns. But.in the rural districts the companion of such vendors is usually a dog of nondescript type. That the dog may be made a useful member of the firm has been proven by a man who travels through Carpenteria, Cal., soliciting scissors-grinding trade. He has a machine for the work and the dog has been taught to fur- nish the power for it. This he does right merrily. He gets on the wheel of his own accord and treads away with vigor, while his master sharpens scissors and knives. To all appearances the dog thinks it is a game devised for his amusement; but the owner believes that a sense of re- sponsibility and a desire to do a full share of the work of the day is stronger than the play spirit in his companion. When business is slack the animal will run to his wheel and bark reproachfully at his master until the man feels obliged to attach the rope which turns the grinder, Chin Chin, the Elephant, Gets Her Winter Shoes Chin Chin walking down a plank wearing her. stylish boots. The elephant suffered from cold feet and was taken to a Boston- shoe shop where she was fitted with the only made- to-order elephant shoes known, The material alone used in making the shoes cost forty dollars Standing on her head in order to allow her hind feet to be measured. Chin Chin was a patient customer, — even when she was required to take this unusual position. Her, © shoes were made of a plump piece of upper stock, a blue collar, a’ juniper sole and a wool skin inner sole. She seemed very well pleased | with their fit and appearance —— Photos by New York Hippodrome Taking her foot measure- ment with fitting stick and tape. According to the shoe man Chin Chin’s size was a full sixteen on the stick and X Y Z wide —all in feet and inches. She is shown here asking the shoe man whether he thinks she ought to wear arch supports or not obi. ye a Aout se soyouss dy} Ut Yyonur se yr Aofus srorpjos ysrBuq 94} “poysojourun seme 3OU st vd} 490]9,0-dAq 3191} patho sd BOY [BOTUOS BIq sy} 0} puNoIZes0y ayy ur od a4} WO1J Bd} 94} JPAOYS 0} sapeds uspooM Bursn o1e UdUI aL Juosy ou} Hs SIOTP[OS YSHNE 94} 0} peyoyedsip pue poxoed ‘papusiq Suloq st yoryM ‘spunod puesnoy} 3YsI9-Aj.10; Zurure}u0o *B9} jo cat Di v é Tommy in ght as Ch | oy Y BF os dee! Sumy & ; ‘ i ne © c om A Mounta amyjord 3 3] 943 We , : | Sattne ‘is we La : pte ees Wes 3 . Arp Aay3 sryy ‘Teooreyo ax] suinq pue wi0}30q ou} bee EF Singita rhe ai 'P ; ataM SazII [LING 94} s9yM o[duI93 & 0} dn pezy ‘s0y}e3 sy bs tone Sais weeps JOAL 9} OFUT UMOLY are soyse 943 ydessojz0yd oy} ur umoys sosrhd | : nae us9q rpoq Bulaq sorpoq Surmoys ‘soSuep snourey s,erpuy Zuoye yeys suruing Vy OSA PUB UAOIE PUB SHLC}[OAUTT, WECTMAN oO ia’s Dead ecko ee nie cis : Si oe uc) 5 rar ° D v <= D < v aon bed D cs = = >] B NX n v On = a] 0 = jam They Grow Cannon Balls on Trees in South America > 3 LZ v ed 4 4 © Brown & Dawson The Cannon-Ball tree (Couroupita guianensis) is a native of tropical South America. It bears large, spherical, woody fruits containing many seeds. In French Guiana the tree grows in great profusion, the natives referring to it as the “baseball tree.”” When full grown the fruit is a little larger than a baseball which it closely resembles even to the seam, which is quite plain in the photograph The fruit is not used for food by the natives v 800 At right: Steel point castings, “nose pieces,’’ as they arereceived at the ammuni- tion plant. A shell is composed of two pieces, the nose piece or point, and the body piece. The nose of the finished shell can be unscrewed from the body ® Below: ‘Truing up a_ six-inch shell after the body and point have been fitted together. Thisis careful work as the Allies are most critical and throw aside any shell which does not measure up to within one- two thousandth of an inch eal © Photos Press Illustrating Serv. Making Shells for Europe—America’s New Above: Cutting the forging the proper length to form the body of the shell. This is one of the most important operaticns 330 At left below: A twin machine that automatic- ally turns two shell bodies at the same time to the right di- ameter. The shells being made are six- inch high explo- sive shells, used in the smaller naval guns and in field pieces Below: Shaping the nose piece to fit the body of the shell. Note the measuring instruments at the worker’s left. These are con- stantly used to guide him in making the nose piece absolutely accurate. The machine is of American make {Industry Which Keeps the Big Guns Barking At right: Boring out the interior of a shell body to make the thickness of the body the proper dimension. Many different sizes are made, vary- ing from one and four-tenths to sixteen inches, but the medium sizes are in greatest demand ‘ i * ~ = < a. se = re ~ > - tp At right below: A pile of rough forgings from which the six-inch shells are made. The shells shown here would last but a few minutes in one of those fierce offensives that were daily occurrences in the early autumn fighting and before Verdun At right below: After inspection each shell is given two coats’ of yellow enamel paint to prevent rust in transit. The shells are hanging by holes drilled in the nose piece. When ready to load, the nose is unscrewed with the aid of these holes a a Pee Sa. (OO Below: Testing the fitting of nose piece to the shell body. The rings shown on two of the shell bodies are for checking the outside dimension of the shells and the gage-stick shown in the third is used to get the depth of the bore Photos Press Illustrating Serv. Abe 831 Temporary Vaults at Panama for the Chinese Dead quouidrys o8ret suo SYeUI 0} paidaT[0D us0q SAvY SoIPOq Jo JoquINU jUDdTIOYJNSs e& [YUN eUTeUeg ye POP 943 9103s 0} BNA sity} pozoaI0 aAvy ssoulYyD oy} Suryeyispun saAtsuadxa ue st Apog o}eredas yova jo Suiddiys sy} sy “pue] oAT}eU SITY UI porting oq 0} sJueM UeUTeUIYD AlDAq uosMEC pus uMCIg GO) 332 a 7 a © A Modern Titan Among the Derricks oie Sawn elerenenree—ovnne maysmromeey oh - hy p * SSeS! — v i 7 . _ . it. Photo Underwood and Underwood The great derrick “‘Hercules’’ lifting a steel mast into position on an unfinished battleship. The “Hercules” is one of the largest electrically-operated and revolving derricks in the world. In spite of its great mass it can be handled by one man. America is enjoying an unprecedented ship-building boom. There are now under contract to be completed in two years vessels to contain a million and a half tons of steel and five thousand tons of wood QQ°Q A Trip to Rio’s Sugar Loaf Mountain ; fe : rs ‘ < QD The aerial cableway to the top of Sugar Loaf Mountain at Rio de Janeiro. The altitude of the plat- form in the fore- ground is about 700 feet, and it takes four minutes to reach it. The mountain is 1,383 feet high. It takes six minutes to reach the top KASS © Newman Traveltalks and Brown and Dawson The trip is one of the most thrilling in the world. The car holds twenty people and the cables are so arranged that if one should break the other would bear the entire weight without mishap - 334 a a Climbing a Mountain on a Rope © Newman Traveltalks and Brown and Dawson The cableway was completed in 1912 and it has since been the main sight-seeing feature of Rio de Janiero. The car runs on eight steel wheels supported by two parallel steel cables, each cable offering a resistance of one hundred and fifty tons. There is a thirty-ton counterweight at each end, making the resistance of the cables ten times that of the car and passengers © Newman Travel- talks and Brown and and Dawson 336 The Homes of Orchids and Dwarfed Pines: Trinidad is the native home of orchids. These beautiful but delicate flowers are reared best in tropical climates, and the year-round warmth of Trinidad is ideal for them. Orchid-raising is one of the chief occupations of the island; and the United States is their largest customer Far back in the twelfth century, one of the great Japanese heroes slew his best friend in a quarrel. In repentance, he became a monk. Down through genera- tions, the caretakers of his temple, skilled in tree-shaping and pruning grew this remarkable tree-ship in his memory : E, P . Queer Uses of Human Hair ts fr "2¥ 2, Bidek eo 2Rieyy fanaa a At top. The Nishi Hongwanji Temple of Japan. Ropes of human hair were used in hoisting the heavy beams In oval below: Specimen of hair rope used in _ building the temple of Nishi Hongwanji. At right: A Korean with the typical horse-hair hat © Newman Traveitalks and Brewn and Dawsc 2 ~ Q* Qa Ice 'Tennis—the New Indoor Winter Sport QaQ It takes both skill in skating and skill in tennis to make this new game inter- esting. The players serve, drive and volley with much of the same energy and dash which they display on ground or cement courts, skates hindering them only now and then when occasional falls occur. ‘These, however, increase the fun. There is hardly a stroke of the established game which is not employed when playing tennis on ice. The expert skater soon finds that he can play a swifter game On ice than on solid ground. It is generally agreed that singles’ play does not offer the possi- bilities of doubles’ because the player cannot be quick enough on the ice to cover his field. On the other hand, there is hardly a stroke of the established game which does not have its counterpart on the ic¢, and in some cases the driving is even more forceful. The court on which the men play is marked out with painted black lines. The regulation tennis ball is used, At first a squash tennis ball was tried, but it proved to be too fast, even though its corded surface took a better grip on the ice than the lawn tennis ball covering Se ee ee a Oe osbenis spunosd sjduis} dy} UO sty} se YyoOns ydsox9 YOM OUOp Ady, ‘suoIssod01d pue sjueo8ed [je ut yred yuezodun ue Avid pue erpuy jo sojduis} oy} ur peddrysiom ose sjeunue ssoyy, ‘[[Ng peloeg oy} Aq UMBIP JOMOUI-UME] UBOLIOUTY UJOpour & YIM eIpUy Ul UME] eB BULMOPT Pig co tk tae o e eo) * = B o =) = 6 3) e ) 5 < = ws DN B 5 Sow Q 2 oe uo) © fet 5) ~ DN A = us) 5 Photographing Peru’s Lonesomest River Wasa cer A tse Ni WL aang < Photo by Pan American Union Picture-making as they do it on the Uca a mahogany log’ and the platform for the and sturdy limbs. The Ucayali is so far in lonely picturesque waters, yali River in Peru. The native boat is hewn from photographers is constructed of light boards land that few travelers catch a glimpse of its For this reason photographs of it are especially in demand 240 obser. Hf OF JxOU IB9q YeTq oY} Se 19391] oureSs dy} WIOIy padojaaop Teoq UoureUuuTS sy, “eIquINjOD ys wo sured Je9q 914M UL ‘eysel[y wos aures (punoisyx9eq 3J9]) Feoq I910K[3 10 enfq 94, ‘se1seds suo jo soseyd s0joo Ajar10ul ywussaide1 03 uMouy Mou nq ‘so1eds JusJojyIp oq 03 pala ~pisuos a9u0 ‘sievoq uoUeUUID pue ‘ozIyYM ‘on{q ore eAoqe dnois 9y} Ul =‘soAT] SY o0yM NOL 19} JOjOS sSIy ssop JayzIENY “HOeIq sABMe JOU Sf Te9q YOR[G 9Y} “J9AMMOFY ‘sesaq Yov[q ore o10y} ‘oorxoyy MIN 0} BASB[Y WoOIy pue BIUJO;[eD 0} suTeYy WO ‘s}sd10} ore 9194} JOAdIOY ALOVSIFT [BINGBAT JO UMoesNnyy Uy eury &q Oj04g 1e€S Blonde and Brunette Bears of One Spec Making Artificial Foliage Nature requires about six weeks to make a leaf; but a good imitation can be made in a few seconds HE modern educators, lecturers and __ exhibi- tors insist upon the details accompanying their illustrations being as true to life as the objects upon which attention is to be focused. If a group of specimens from Africa or other parts of the tropics is to be shown, it is considered necessary to have a tropical atmosphere and background. This is not always possible, but the attempt is never an absolute failure, since Sci- ence has devised so many ways and means of reproduc- ‘ing natural objects. Especial success has been achieved in representing trees, flowers and shrubs, so that animals, for instance, may be shown emerging from among just such thickets as they would if alive and in their natural haunts. Usually when a tree is to be represented, models of the leaves of different sizes are secured and plaster molds made of the upper and under sides. A fine wire, with a little raw cotton wound around it so as - to taper to a point, is laid into the impres- sion of the midrib. Then a thin layer of cotton is spread evenly so as to cover the leaf impression, and a little hot melted wax, Below the TYPE METAL MOLD 4 tural colors Above: The clamp in operation. Two leaves are being cast at once. and the leaf molds are shown Groundsquirrels tinted to nearly the required shade in their natural of green, is poured over it. The mold haunts. The " A leavesonthetree Of the other side of the leaf is then were prepared pressed down upon it. The wax by the method soaks through the cotton and spreads describedinthis evenly, making a perfect cast. article. They A hod a ki i, were graduated new method of making these in size and _ leaves as well as parts of flowers, tinted in na- which will vastly reduce the labor of the operation, has recently been introduced by Mr. A. E. Butler, of the American Museum of Natural History in New York City. He has devised the clamp shown in the illustration. A plaster of a fresh leaf. This mold is reproduced in bronze and then fitted by means of screws to one side of the clamp. A counter mold is made in type metal on the opposite side of the clamp, thus setting both molds of the leaf in perfect contact position. The cotton and wax are introduced as before. By the closing of the clamp, the two molds are brought together so exactly and quickly that it takes only a few seconds to turn out a leaf. A leaf can thus be made much thinner than with the plaster molds. By using a number details of the clamp BRONZE MOLD may. be left to cool as others are being poured. The leaves and flowers are more delicate, . also, and _ conse- quently truer to Nature than when made by the older method. Therefore when they are wired to the forms representing the trees and shrubs the animal itself, whose environment is being considered, might be deceived if it were a real creature and not merely a product of taxidermy. But the most obvious advantage of the method lies in the reduction of labor. OAD mold is made from the face _ of clamps, one leaf — —— a er 3 telegraph nor was Morse the sender ) EN T= MS ONE CENTRO EN I . Popular Science Monthly What the First Telegram Really Said ONTRARY to general belief, ‘What hath God wrought?” was not the first message to be sent by of the first communication. - Instead, it was sent by one of the committee who were debating upon the proposal of Morse, the inventor, to string a telegraph line from Baltimore to Wash- ington. Mr. Morse, who wanted to end the discussion and at the same time demonstrate hisinvention, strung a wire from the committee room to the top of the Capitol. One of the com- mittee, who was opposed to President Tyler, wrote “‘Tyler deserves to be -hanged.’’ This was received by the man at the other end exactly as it was composed. A Horse-Collar Grows on a Tree REES assume every shape im- aginable, but it is a rare one, indeed, that has a perfect horse- collar growing on it. The horse- collar illustrated came from Na- ture’s own workshop in the woods of northern Michigan, where it had been grow- ‘ ing undisturbed for years until found by the woods- men. It is possible that the horse-collar was formerly the top of a slender sapling near the tree on which it was found, or perhaps it was a young pliable limb growing on the tree itself. It was evidently twisted around the tree and fastened in such a way that it re- mained in that position. This might have been done by some person, although it may possibly have come about from some natural cause. The collar is grown so perfectly that if the proper rings or snaps were placed on it, it could easily be put to actual use. Compared to the leather collar it would last twice as long, but it would not afford the horse so much comfort. This horse-collar might have been the top of a sapling, or a pliant limb which was made to encircle the base of a larger tree Twenty-five feet of shore were taken away and old walls and foundations removed by the dragline excavator equipped with a one-yard bucket Widening a River with a Steam Shovel CIENCE is proving that there is no impossibility to the truly ingenious. ‘ The widening of the Sandusky River, at Tiffin, Ohio, recently was a case in point. Primitive man would have waited patiently for the river to widen its own banks or for storms to wear them away during the course of years, but the engineers made the experiment of using adraglineexcavator and accomplished their purpose in short order. Twenty-five feet of the shore was to.be taken away, necessitating the removal of old walls and foundations. The exca- vator, which carried a forty-two-foot boom and was equipped with a one- yard bucket, had no difficulty in clearing away the most formid- able obstructions, al- though several of them were partially under water. It was also possible by this means to load wagons on the street level, and the river bank was soon cleared away. The apparatus moved by means of caterpillar traction un- der its own power as fast as the widening of the river on the Tiffin side was completed. MOVING Pic HEALTH CAl /— STATE BOARD OF HEALTH Popular Science Monthly ee, ated A lecturer has charge of the health car and gives an open air session wherever he stops. Teaching Health Lessons with Auto- mobiles and Motion Pictures N order to extend its campaign of educa- tion among school children, the North Carolina State Board of Health is using an automobile that is a veritable moving picture booth on wheels. The car carries a projection machine which can be taken out and placed on the ground so as to throw a picture on any wall. The power is furnished by an engine generator. A large sheet is hung on the wall when the state officials wish to show a motion picture. The department has its own reels, to point out reforms which it advocates. A Motor-Manikin Which Waves Its Arms and Yells OU have seen those strange little folk - that decorate automobile radiators. Well, the inventors have add- ed a new member to the family —a manikin which throws up its arms to indicate the direc- tion to be taken by the car and then shouts menacingly at you. A simple horn attach- ment does the shouting; the arms move in and out by means of magnets. Claud A. Reese, of Bowling Green, Florida, has devised a manikin with its arms pro- vided with electric lights so that it will work at night. It has been found possible to show fairly clear pictures even in broad daylight When the driver presses a button the figure’s arm goes up, and by pressing another button, which operates the horn, the mouth of the manikin opens and he yells realistically. ; The arms are fastened to the figure’s body with hinges and are operated by a pair of electromagnets. The magnets are placed in the upper parts of the legs in a vertical position so that they carry move- able armatures. Rods connect the arms to the armatures, and when the solenoids. are energized a downward or an upward pull is communicated to each of the arms. With its arm-lamps lighted, the figure makes an impressive appearance, which. is sure to be noticed. SSANY, The motor manikin’s arms indicate the direction which the car will take as he shrieks a warning. At right is shown the interior mechanism and magnets of the figure a ey ee ne ne ee "fo ee ed Hi ark ay _ ern ee ee ee eee ee TEESE EL FHF F er aE MS ae eR eer now as an aid to digestion. Popular Science Monthly ~ Digest Your Food Electrically! You Can Do It with a Wireless Apparatus IRELESS engineers have perfected the ‘“‘spark’’ system of wireless teleg- raphy, until now powerful currents are perfectly controlled. These currents have a decided medical value, and physicians were not long in employing them, first of all in the ‘‘baked’’ cautery method for making bloodless operations. Heré sets of small electrodes are placed opposite the organ to be operated upon, and a _ low- voltage current is applied which may change its direction as many as a million times in one second. Thecurrent can be directed upon the partic- ular organ until it becomes heated to such an extent that it is actually “baked!”’ The cauter- ized organ may then be removed, if neces- sary, with littlechance of blood poisoning. The “wireless apparatus” shown in the accompanying illustration is being used I The patient illustrated was so weak that he could not digest enough food to keep himself alive. The three large electrodes that are shown placed against his side were connected with a branch circuit of the apparatus. The number of times in a second that the current changed its direction was then regulated in the main circuit by the large wire coil seen near the head of the physician. The strength of the current was carefully adjusted, and when the proper values were ob- tained, the electrodes were ‘thrown in” with the main circuit. The current, as it coursed through the stomach and its connecting organs, so stimu- lated the cells that they were soon able to do their work again. The patient could not digest enough food to keep him alive, so electrical stimulation of the organs was resorted to and he recovered The pigeon-hole idea applied to traveling bags. of Every inch of space is utilized, even the flaps 345 Will the Gasoline of the Future Be Mined? HE latest estimates of the United States Geological Survey show that if gasoline continues to be used up at the present rate, all the petroleum fields now in use will be exhausted before 1950. Where, then, will our future gasoline come from? Billions of dollars are involved in the question. The probable answer is that “mined” gasoline will be used. Colorado, Utah, and other Western and Middle Western states con- tain extensive oil- bearing deposits of bituminous shale. Crude oil can be ex- tracted from them and this can be distilled further to ob- tain gasoline. Enough gasoline could be produced in this way to equal many times the amount obtained from all our present-day petroleum fields. You Don’t Need to Dig in This Bag to Find What You Want TRAVELING bag which is a veritable wardrobe trunk, if one counts its humerous trays and compartments, has been invented by Samuel H. Wallach, of New York city. The trays are placed so that they taper upward toward the top. Access to them is gained by opening or separating the walls of the body portion of the bag. The side and end walls of the bag are securely fastened together above the upper tray by a buckle. Several large envelope- shaped compartments are provided for soiled linen and small ar- ticles. Only a single lock is necessary to give access to any or all parts of the bag. Each wall of the bag is provi- ded with pockets into which articles various sizes may be tucked. HE officers at the United States sub- treasury located in Chicago found that there was a small but persistent shortage in the money- load lots from the banks of the. city, Careful watching showed that the Spying onthe men full amount was sealed in inthe sub-treasury ¢ h e as the money-bags ba are being counted gs at the banks, but the count was invariably short in the sub-treasury, the difference usually being two, three, or four dollars per bag. The Secret Service men were called in to solve the mystery. Captain Porter, in charge of the investi- gation, was convinced that the stealing was occurring in the sub- treasury o eZ sel ae, and not in the banks or on the trucks during transporta- tion. To make sure, he had a_ small chamber built in the top of a toilet room opening from the room where the The mouth of the bagis drawn into accordion-like folds OAR bags delivered in truck- Carrying the money-bags sent by the banks of the city by truck-loads to the sub-treasury where they are counted A cord is run through a lead seal and a steel pin is run through each separate fold Mechanics of the Secret Service - Protecting the Nation’s money-bags By M. McGuire Telford — bags were received and counted. A tiny crack was made near the molding so that a man might secrete himself in the chamber and keep the workers in the room under observation. Captain Porter posted himself in these cramped quarters before the beginning of the day’s work. As they came in, the money bags were counted by a young man of twenty-five whose work was supervised by an older and highly trusted employee. Captain Porter saw that as the young man counted the ‘bags he tested the tightness of the fastening on each. Most of the bags were quickly passed along, but a few were set aside in a row on the table. When all were counted and tested the those on the table. With marvelous quick- ness he pulled down one of the folds on the first bag through the cords loosely fastening it, thrust in his fingers, withdrew two or three silver dollars, and in a jiffy pulled the fold back into place. Each of the other bags was treated in the same fashion, the older man in the mean- time scrupulously keeping his _* back turned so as to see nothing. On the third day of £ the investigation, Captaing The new sealing device for the money-bags young man turned to a a ee a —e , f | : Popular Science Monthly Porter called in a high official of the sub- treasury to see with his own eyes. That worthy was so excited when he saw the young man extracting the money that he came near precipitating an. immediate explosion. Legal evidence was secured, and final- ag ly a confession obtained. It turned out that the young man had been doing all the actual stealing; he asserted, however, that the older man had shared in the loot, though this could never be proved. The work of Captain Porter showed that there was no per- fect means of securing money bags. g4@® Sealing-wax is not only easily broken or de- faced but it can be readily manipulated so as to duplicate the impression. Wax is even less satis- ~ factory. Lead seals can be Iropenin and replaced. With any of these materials a single fold can be pulled down, as described above, and part of the contents of the bag so carefully extracted that only weighing or counting shows the shortage. Captain Porter proceeded to invent a safety seal that seems to have made successful tampering impossible. Like most effective inventions, the dévice is remarkably simple. A cord is run through a lead seal and placed around the mouth of the bag, which is drawn into accordion-like TF e SARE Re First National anh Sipsimors. No 4| Denomination} cagnsegominstion ESET aS. SE Tk FIVes “= i : | eT ff ; aled AHH Io) Teall $ 7000. Date = — A bundle of bills ready for shipment. Although securely sealed it will not escape from the official eyes of the Government until it reaches its final destination The sealing instrument by means of which the lead seals are crimped so as to make it impossible to loosen the cord. operated by means of a lever handle 347 folds in the usual fashion. Then a steel pin, attached to the seal, is run through each separate fold. With a sealing instru- ment the lead is crimped so as to make it impossible to loosen the cords without destroying the seal. Thus it is impossible to pull down a separate fold, as the steel pin holds each in place. A loosened cord be- trays itself. . Another baffling — prob- lem closely akin to that of the money bags is the theft of one or more bills from a packet shipped from one bank to another or sent to the sub-treas- ury. Ordinarily the bills are bound into bundles containing ten thousand dollars, and a slip is placed on.top show- - ing the num- ber of bills and their denominations. Often an unscrupulous clerk or messenger ex- tracts one or more bills and then claims that a mistake has been made in the counting and packing. With the ordinary binding, there is no absolute means of proving him to be wrong, as the packet is apparently intact. A safety currency press invented by C. H. Bohanan makes this sort of theft impossible. Ordinarily a packet of five hundred dollar bills is from 214 to 234 inches thick. In a press it is reduced to about 134 inches and it is then bound with three sealed cords. Owing to the compres- sion it is impossible to extract a single bill without cutting all three cords. An inner steel reinforcement in the lead seal makes breakage impossible; nor can the grip be removed. By breaking the middle cord and one end cord, the contents may be counted. If there is a shortage the whole packet may be returned to the sender with indubitable evidence that the interior has not been tam- pered with. The compactness of the bundle also makes this device useful in compressing bundles of checks, drafts, and vouchers for storage in vaults. It is 348 The Latest Rival of the ‘*Punch and Judy’’ Show Ro unnumbered years, it seems, the Punch and Judy show has held its place in the affections of the juvenile public. Now, however, it can no longer hold undisputed sway. A new toy em- bodying the same general principle, has been invented by J. A. Dunigan, of Albany, N. Y., which is not only as amusing but is capable of great variation. As shown in the illustration, a number of toy actors are mounted on an endless. belt which extends across a guideway in the floor.of the miniature stage. The belt is composed of a folded strip of stiff material into which the base pieces of the toys are inserted and by which they are carried across the stage during the performance. Speaking parts taken by persons behind the scenes increase the interest and the liveliness of the act. Any number of toy figures may be used. They are easily removable so that there need be no monot- ony in the performance. How the Office Adding Machine Is Employed in Surveying HE illustration on the right looks to be a photograph of one of those ultra- busy men who can not leave their work behind even on a vacation trip. But although the machine in use is the regulation adding machine, such as will be found in the equipment of any office, it is also a part of the traveling equipment of the surveying parties which the United The figures apparently « dance across the stage on a revolving belt Popular Science Monthly States Geological Survey is sending out to do special leveling work. The adding machine is conceded to be much more reliable than the ordinary clerk, male or fe- male, and the practicability of using it for recording read- ings of the level rods was work done recently by Government surveyors in certain sections of Florida and Indiana. As many of the observations are made on railroad rights of way, the Government men _ use motor velocipedes to trans- port themselves and their equipment from place to place. When in use, the adding machine is placed firmly on the base of the velocipede and is then strapped on. It is possible to move the car and apparatus along the rails without disturbing the arrangement. This is said to be the first time mechanical adders have been used in the field. The United States Geological Survey reports that recording can be done in this way more quickly and with less likelihood of error than by the old method of entering observations in a record book. The Government surveyors use motor velocipedes on which the adding machines are strapped for recording readings proved in connection with. « ee eee hte Popular Science Monthly A Cargo of Dried Codfish : Sank a Schooner | Be gethee Sank Big Schooner”’ was the title of a news item of recent date, which besides being most un- usual, seems to open up a new method of sinking wooden © ships of the nations at war at a trifling cost com- pared with the present $5,000 to $10,000 torpedoes used by submarines : and destroy- pes) ers. Accord- | i ing to the ite ae survivors of ey the vessel, Ben. By codfish ac- —sfa tually sank Ya her, although it took more than one to do it and it was several _ days before the vessel During a heavy sea the codfish became watersoaked and 349 Discovering the Spy’s Secrets by Means of a Lemonade Bath RAVELERS through Germany are likely to regard with resentment the many precautions which are taken against spiesduring the wartimes. This is only natu- . ral among the freedom-loving Ameri- : cans. They find the necessity for the various passports which are de- Ke manded of them at every new * step of their journey a veritable nuisance. Each traveler needs a certificate of good conduct; one showing that he has no debts; one from the secret service showing that he is not sus- pected; a Similar one from the mili- tary authori- ties; one showing that he has no <—S had to be abandoned. swelled so much that the seams in the planking of that part of the vessel where the fish was stored were forced apart and the crew was compelled to abandon the ship vermin; one signed by the New Eng- land’s sacred cod has been famed for many things, but this seems to be its most notable achievement. Of course the cod did not torpedo or ram the vessel because she belonged to any particular enemy. They sank her simply because they were inside the ship and be- cause they had too much water. The strange incident happened in this way. _ The schooner Ponhook, under a captain and crew of seven men, left St. John, N.B., for the Azores, with a cargo of dried cod- ,--g& fish. Soon afterward she ran into a heavy sea and shipped considerable water. The dry codfish absorbed this like a sponge, and it was but a couple of days before the expansive pres- sure of the swelled codfish had forced open the seams of the vessel’s planking so that the water began to seep in, little by little, as shown in the accompany- ing sketch, until the ship was beyond saving and had to be abandoned. FORCED OUT CAUSING LEAK PLANKING = Showing how the pressure exerted by the swelling cod- fish forced the packing out of the planking, causing leaks consular officers; a permit to travel, and a permit from the station master to use the train. But the entire collection of passports will not exempt him from being subjected to the lemonade bath, which is the last cry in the methods employed for discovering spies. The necessity for the lemonade bath arose when it was found that information and maps were being carried over the border tattooed on the skin of the informants. The skin-writing is done with a chemical which when dry is invisible, but is gjss brought out by another chemical when the spy reaches his headquarters. The citric acid of the lemon juice serves to bring out these written characters also, or to destroy them. As there is no way of telling whether or not a traveler is a walk- ing manuscript, written all over or in spots, the entire body is given a vigorous rub with the lemonade. The only way for man, woman or child to avoid it is to re- frain from attempting to cross the German border. 7 PRESSURE A < FROM SWELLING Tricks of the “War Photographer” How a remarkable ‘‘air’”’ battle is staged thousands of miles from any battle-field—in New York! By J. A. McManus I F F—Bang—Boom—Crack—Crash— B or any other words that convey the impression of bursting bombs, the hum of many aeroplane motors and propel- lers, the sounds of big ‘‘Archibalds”’ sending forth their messages of death and destruction, the echo upon echo of the boom of bursting of big shells—it’s all there in the accompanying photograph ‘‘War in the Air.” Is it not? A quiet photo- graphers’ dark-room, some stories above the noise and bustle of New York’s beehive, an en- larging camera, some en- larging paper, size 11x14, a collection of negatives, (Picture No. 3, shown at Numbers 1-2-3-4-5-6) photograph of a balloon that was set on fire at Sheepshead Bay, N. Y., by Daredevil Rodman Law, and which really looks like a bomb explosion; (Picture No. 7, which is a close-up photograph of an Allied aero- plane, shown also at to represent a Photograph of a balloon that was set on fire at Sheepshead Bay, New York, by Rodman Law. It is used negative and in the fact that once a spot on the enlarging paper is fully exposed, you cannot expose on it again; but, if the first exposure is just a little under- timed, and the second a little under also, both exposures will blend to- gether when put through the developer and fixing bath. : Before the actual ex- posures were made, a sheet of white paper of the same size as enlarg- ing paper, was placed on an enlarging board. The different negatives, with the exception of the cloud negative, were thrown on it through an enlarging camera, and the relative sizes and positions were plainly marked out on it, as they appear in the accompanying illustrations. Numbers 1-2-3-4-5-6 (on picture on following page) are exposures of the same negative through a ragged hole in a sheet of paper held between the light from the lens of the camera bomb explosion 8 on the following . page); two photo- graphs of aeroplanes in air, Number 10 be- ing thesame as Num- ber 9, but thrown out of focus slightly; a cloud scene taken over New York; a fund of imagination; a sense of proportion; unlimited patience— result, a composite picture that looks remarkably like a real air-battle photo- graph. The secret behind it all is in the right timing of the exposure of each A close-up photograph of an aeroplane belonging to the Allies. is used again and again but differently ° focused and in various positions and the paper on the enlarging board. This exposure is called ‘“‘vignetting.” The paper used was large enough to block out all light from the rest of the enlarging paper and was moved with a cir- cular motion around the spot exposed to prevent the edges of the hole from showing in de- veloping. The differ- ent positions of the same negative were obtained by turning the paper on the The same picture 350 A Perilous Air Battle—in a New York Studio Before the actual exposures were made, a Breas et: SAP of the same size as en- ing paper, was placed on an enlarging board. The different negatives, with the ex- ception of the cloud negative shown on the right, were thrown on it through an enlarg- ing camera, and the relative sizes and Positions marked out. Numbers | Wie se, Se and 6 are exposures of the same negative through a ragged hole in a sheet of paper held between the light from the lens of camera and the paper on the enlarging board. Numbers 7, 8, 9, and 10 are differently focused views of the same aeroplane 352 Popular Science Monthly enlarging board. Before each exposure, the size and position was obtained on the sketch of the whole picture. With the ruby or orange cover on the lens, the enlarging paper was placed exactly over the sketch paper. Then the exposure was made. Both papers were taken down before the next exposure, or changing of negative. The effect of distance is obtained by making Hoisted by an Auto- mobile up to the Clouds — Bape the queer- est use to which the automobile has been put is that illustrated in the photograph below. It shows a steeplejack rest- ing confidently on his. nerve and on the end of end of which is attached to an automobile below. He is being hoisted | to the top of a gigantic the object smaller and slightly undertiming the exposure. The longer the exposure, the sharp- er, clearer, and nearer The photograph marked 9 is the same as Number 10 except that the latter is differently focused in the air, to give atten-. tion to the antennas. of the largest wireless plant in the. United States, which is located at Bo-, the object will appear to be when the paper is developed. Exposure No. I was over a section of No. 7, and when the latter was made the former blocked out certain parts. In exposures 8—9-10 the appearance of dis- tance was obtained by gaging the time of exposure and the size, and also, as in No. 8 linas, California, about. fifteen miles’ northwest of San Francisco. A. A. Isbell, engineer in charge of the plant, states that the steeple- jacks prefer an auto- mobile to a horse for the hoisting, since the flat cattle range surrounding the base of the masts make the automobile practicable, and the ma- and 10, by throwing the negativesslightly out of focus when exposing. In exposure No. 11, the cloud background was exposed over all the paper and greatly enlarged, only a section being used. Care as to the correct timing had‘to be taken. In fact the exposure was undertimed, as the least bit of overexposure would have spoiled the entire effect. Care was taken, at all times to avoid fog- ging of the enlarging paper. A variety of beautiful as well as startling pictures can be made by this process of composite enlarging and printing. - The average amateur as well as _ professional photographer has any number of negatives which when combined will make truly wonderful pictures—pictures that cannot be distinguished from actual photographs. But patience is necessary. The ‘War in the Air’’ took four tries, and the last pic- ture consumed one hour and _ twenty minutes making the exposures. and insures more steadi- ness in the ascent than a horse. The plant has nine of these great tubular steel masts, so that considerable work aloft is necessary. The other end of the cable is fastened to a moving automobile which is hoisting the jack three hundred feet to the top of the mast a steel cable, the other steel mast, towering h hi; gh chine is more reliable — f ‘+e a ee ee a ee ee ea he ne ee Se, eee es = Popular Science Monthly 353 Helping the Deaf to Hear with a New LSet Electrical Ear ee NEW instrument to help the hearing of the deaf is so constructed that buzzing and gratingsoundsareentirely sifted out. The sounds received are actually increased in volume so that practically every partially deaf person can hear withitsaid. The clearing of the tone is accom- plished by carrying the sound- waves through the receiving mechanism in much the same way that a stream of water is sprayed out by the presence of a button in the middle of the nozzle. Hence thesound does not bound out of the instru- ment, but is carried around and thrown back on the diaphram of the microphone, after all rumblings have been lost irs SOUND ENTERS Above: The electrical ear, showing how the magnifying of the sound is accomplished by the drum-head The transmitter is easily concealed in the clothes and the ear disk is reduced to a very small diameter ventors who perfected the wire-tapping telephone in- strument which figured so in the steel passages correspond- . prominently in the news a few ing to the auditory canals of the months ago, and they have normal ear. adapted to the perfection of The magnifying of the sound depends the new ear-phone the same principles on the drum-head or sounding board which which made the “‘listening in’’ inaudible. is buried in the heart of the instrument. Heretofore, electrical manipulation and The sound, after entering, is carried around tuning have been the only means of increas- through the sound chambers. It strikeson ing the efficiency of the microphone, but the curved surface of the drum-head, from with the new ear-phone, this electrical which it is deflected through a perforated adjustment is aided in its work by the screen to the diaphram of the microphone. ingenious mechanical developments of the The drum-head is made in varying degrees drum-head and the open spaces inside the of curvature, and of different materials and instrument. thicknesses. The disk that goes to the ear is reduced The makers of the instrument have also to a diameter of an inch and one half, prepared a testing system, not unlike an and the transmitter, three inches in diam- optician’s test case, by which a physician _ eter, is easily concealed in the clothing. can determine exactly, not only the proper curvature and thickness of the drum-head, A New Pipe Which Is Sanitary but also the material of which it should and Nicotine-Proof be made. This varies from brass to lead, IPE smokers are ever on the alert for a with silver, rubber and glass in the list. It pipe which is nicotine-proof. The dis- has been found that the material gives the advantage with pipes wKich claim to live quality which is vital in getting just the up to this feature is that they cannot be ahs ely ie: ae hes sense of hearing cleaned readily. They clog up with small isleft. Itis claimed that articles of tobacco. by careful fitting, as to CENTER HOLE BURNS EVENLY The pipe illustrated form and material, i ay igebesiet hens aterial, in No MoIsTuRE Passes HERE CaN be cleaned whenever the: drum-head, the deaf Ni OF SMOKE CLEAR the smoker wishes. Fur- Sap a be ace o a CLEAN WELL thermore, nicotine can ear nearly all words and ee in their — stem, since the stem is natural tone. ? : is i , a t ei The internal construction of the ee allowing Ww instrument is pipe, showing the cleaning well all moisture to drip into the product of the in- and the path the smoke takes an easily cleaned well. not bedrawn through the : Rescuing a Drowned Locomotive How a one hundred and twenty-ton engine was raised from the bottom of the bay HILE handling a pile driver equip- ment used in rebuilding an old trestle at San Pedro, Cal., a one hundred and twenty-ton locomotive broke through its track, toppled over the piling supporting the trestle and fell down a slop- ing embankment to the bottom of the bay. It went through thirty feet of water and half-buried itself, top down, in slime and mud. A floating derrick barge with equipment powerful enough to raise the engine was not available. A local railroad super- intendent finally de- vised the ingenious method illustrated by which the big engine was successfully re- covered. Two barges, each of two hundred-ton capacity, were floated the engine and. its tender right side up. This had to be done in two operations as the tender and engine could not be separa- ted, owing to their depth in the slime. To support the engine, three clusters of large timbers were rigged across the barges. Two of these were placed at each end and one in the middle. From these supports one and one half inch steel cables were dropped to the engine, passed under it and made fast to it by the diver. When the cables were all made _ fast below and drawn tight about the uD timbers above, fif ton hydraulic jac were placed at each end of the supporting bridging. As the sup- ports were jacked up, railroad ties were in- serted under them for out over the approxi- mate location of the “drowned’’ locomo- tive. They were placed parallel to each other and united at each end by two girders made of three logs of twenty-foot piling lashed together with a four and a half inch manila rope tied about the piling and bits. As each turn of this lashing was made a hoisting engine was used to pull the rope tight... A complete coil of rope was used at each end of the girder, and several short lashings were made between the ends as well. The first operation was to turn the engine and its tender right side up by means of cables attached by a diver TIMBER BRIDGE FOR ateeesagne? shown in the pictures. After the engine was turned rightside up the cables had to be readjusted and more units attached. The hoisting then con- tinued until the cribbing had been built about ten or twelve feet above the deck of the barges. Extra cable lashing was put on to hold the engine in suspension until the cribbing was removed and the supporting timbers lowered back to the deck of the 4 By repetitions of this pete 4 barges. the engine was elevated — sufficiently from -the © Before the hoisting work started, some ob- jectionable pile stumps had to be sawed off close to the bottom of the bay by a diver with a short piece of cross-cut saw. The first operation, necessary was to turn Railroad ties TIMBER BRIDGE FOR HOISTING inserted for cribbing under the supporting bridging. hoisting was continued until the crib- bing was ten or twelve feet above deck bottom of the bay, so that it and the barge on to some mud flats — - half a mile distant and — close to a spur railroad — track. a equipment was pulled 354 cribbing inthemanner aground byalocomotive. — rs eS The whole — _ could be towed intact — a Towing the Recovered Engine to Land Two barges were joined together by means of girders, and a hoisting engine was used to right the locomotive and hold it in suspension between the girders until the barges could be towed onto some mud flats close toa spur railroad track, drawing the engine with them 356 STAKES SUPPORTS Mn eee FRAME REAR SPRING WORM GEAR WORM-WHE CASING y_ | ROD” REAR AXLE WORM WHEEL PROGRESSIVE GEARSET DRIVING SHAFT. Popular Science M onthly BODY SIDE BODY TRANSVERSE THREE- SPEED CHANGE - GEAR LEVER ASOLINE mA IN rN FOOT BRAKE ON KIN DRIVING TOC SHAFT HAND BRAKE "BOX RUNNING BOARD CLUTCH FRONT SUPPORT FOR RADIUS ROD & TORQUE ARM KNUCKLE If you took a huge knife capable of cutting hardened and heat-treated steel and slashed it dewn through the center of a modern motor-truck from one end to the other, the result would be something like this picture, in which all the vital parts of the vehicle are exposed to view. Note how compactly the internal parts are arranged despite the long wheelbase of the vehicle, and how few rods are exposed to the.wear and tear of travel. A Pushmobile De Luxe for the Youthful Speedster THREE-WHEELED vehicle built for boys and girls from eight to fifteen years of age is the latest addition to the pushmobile family. It is operated by hand by means of a forward and backward lever and rack movement. As shown in the accompanying illustration, it is made of bicycle parts and is steered with the feet. The front and rear wheels are placed far apart to prevent overturning. It is equipped with a bucket seat of the rac- ing car type, and other up- to-date para- phernalia. The latest thing in pushmobiles. “It is operated by means of a lever and rack movement and is equipped with all the pushmo- bile refinements including a hand-horn and an electric searchlight Another significant feature revealed Where Is the Automobile Seemingly Most Popular? WENTY years ago the horseless car- riage was in its earliest experimental stages. To-day there are more than two- and a half million motor cars in the United States—a car to every forty-one persons! In sixteen years the revenue derived from automobile licenses alone has grown from less than a thousand dollars to more than eighteen millions in the year 1916. Ninety per cent of this amount was spent on road and highway improvements. But perhaps the most interesting facts in the automo- bile industry relate to the car-per-pop- ulation figures. f) while New York, our richest q . State, has a car to every thirty- Ya = nine persons. In other words, York, and twenty | times as many as Tennessee. The Southern population, while the Western States have the largest. Iowa, for instance, has ~ acar to every fifteen persons, Iowa, in proportion toher population, has twice — as many cars as New States have the lowest ™ averages of automo- biles according to Popular Science Monthly STEERING WHEEL FILLING CAP STEERING COLUMN ra SPARK ADVANCE & THROTTLE CONTROLS WATER \MOTOR HOOD PISTON es: ides WET. MOTOR & Pa eaieiebee (RADIATOR ll GEARED NG A ncryi SELF STARTER LUBRICATING \'CRANKSHAFT re) " CONN IL PUMP ECTING RODS is the number of gears and gearsets. Note how carefully the weight has been distributed. This is a most important consideration in the construction of the modern motor-truck and automobile Two Workingmen’s Tandem Motorcycle IFFERING from other two-seated motorcycles in that the riders sit side by side on a common seat instead of one be- hind the other, the motorcycle shown in the accompanying il- lustration is used by two Norwalk, Ohio, workingmen to ride to and from their work each day. The machine, with its ability to carry its two passengers between seventy-five and one hundred miles per gallon of gasoline at speeds up to forty-five miles per hour, offers a quick and cheap method of getting to and from work. Fur- thermore, the weight is more evenly distributed _ over the rear or driving wheel, effecting a considerable saving in tire wear and insur- ing easier and steadier riding. The man driving the machine generally sits on the left-hand side, because the clutch is operated from that side. The old idea of sitting behind the driver gives way to something better. men sit side by side on a common seat 357 Making the Front Axle Help in Driving the Automobile HE idea of using all four wheels in driving an automobile has struck many an engineer and has tempted him to work on the problem. The demand of the automobile-buying public seems to be con- stantly for more power regardless of whether it affords additional comfort or not. Ob- viously, the advantages of making the front axle help in driving, lie not only in obtain- ing far better traction and thus more power, but in simplifying the driving gears as well. From the standpoint of the automobile engineer the great difficulty, however, has been with joints on each end of the axle, so designed that they allow the wheels to swing about them and thus transmit the turning power at the same time. In try- ing to combine these features in one axle joint many inventors have met their Waterloo. The fact is that the stress from thé transmission, plus the stresses which would be obtained from riding over rough roads would prove too heavy a load for a joint of this kind to withstand. Notwithstanding these difficulties, it appears that a Dutch engineer, Peter J. Batenburg, has con- ceived a workable plan. By relieving the axle joint of the function of serving as a turning support, Mr. Batenburg uses it to transmit power only to the front wheels. The casing around ‘the axle members is made in- to a joint which works very much like a guided ball- and-socket joint. It is this joint which takes up all stresses due to turning and to supporting the hody of the auto- mobile. The axle it- self is made flexible by a suitable joint and it fits loosely inside this casing. It makes easy connec- tion with the hub of the wheel through a steel plate at its end. All stress is taken up by the supporting joint and no weight is left to be borne by the weaker axle inside. The two > : ; { , 4 A handle and lifter of 4 non-rusting metal, for 4 removing the paper ; covers from milk bottles 4 An arm-band for use with the gas or eJectric iron, or with any tool hav- ing a tube to be kept out of the way An aluminum egg- beater that does not waste the con- tents, ard is easily cleaned. - The gears are machine cut At right: A burglar- proof galvanized iron delivery box with three com- partments. The weight of the par- cels placed upon a false bottom in the box automatically locks the section At left: The box is fastened to the side of the house just below the window- sill. The top lid is automatically locked or -unlocked by the same action which closes or opens the window REMOVABLE CAP COVERING SOCKET HEATER Weel aSBESTOS @ HEATER INVERTED gy, 10 FORM LAMP. SHADE A complete egg service consisting of a gilt-lined silver-plated egg- cup, salt and pepper shakers, spoon, and rack from which the china plate is easily detached A combination electric cooking utensil, heater and lamp. Metal plates fit in the invert- ed shade for cooking Oro MOLL Cor cL Denim or khaki overalls for women! : latest idea for the strenuous Spring housecleaning A new type of cas- ter which fastens around the furni- ture leg and looks like a metal finish A Japanese method of hanging flowers and plants. The pots balance each other, so that either can be readily pulled down to water the flowers A shoe and slipper container which resembles a cretonne- covered shirtwaist box Housekeeping Made Easy LE cis The very The overalls are voluminous enough to enclose the skirts and protect the stockings A New Ball Differential for Automobiles It will enable a car to get out of a hole when only one wheel grips NEW differential for automobiles has just been put on the market which differs from all previous types in that the differentiation is secured not through gears but through the friction of steel balls running in grooves. It has an ‘advantage over former de- signs in that while the power of the motor is differentiated between the two wheels in the usual manner for corner turn- ing, it will still allow a car to pull out of a hole when only one wheel has traction. The center plate is of chromo-nickel steel into which are fitted steel balls As shown in the accompanying views, the device con- sists of a con- ventional differential casing at the center of which is a plate carry- ing eight steel balls arranged on two concen- tric circles. These balls move in cres- cent-shaped grooves in two disks, one on each side of the plate. The disks carry the ends of the axle shafts. Each groove is deep and wide at its middle, tapering off to points at the ends. The deepest part of the groove and the thickness of the center plate are each one-half the diameter of the balls. When any one ball is at the deepest part of the groove on one disk, it is at the end of the corresponding groove on the other. The transmission of the motor power through the large differential % LJ ‘ONLY OUTER ROW OF BALLS. SHOWN FOR CLEARNESS The differential in position and the relation of the work- ing parts to each other -The balls move in crescent- shaped grooves in two disks ring gear to the plate carrying the balls creates a thrust which tends:to force the disks apart, causing them to press against. grooved washers in the ends of the casing. — When the car is running ahead, the plate and the disks revolve as one piece, like any differential, the thrust ex- erted by each disk and the torque on each — wheel being equal. In turn-~, ing a corner, the power. delivered es to the wheels is un- equal, due to the tendency of one wheel to turn faster than the other. en Pim The power shaft of the automobile turns the ball-plate This permits the balls to revolve from the grooves of one disk into those of the other, causing one disk to move faster than the other and similarly allowing the outer wheel to turn faster than the inner. If one wheel is spinning, The gearless dif- the friction ferential which x ; gives a positive induced by pull at all times the disks arrests the — spinning wheel and converts its motion to torque on the stationary one, the spreading of the disks acting as a brake on the spinning wheel because only on that side is there relative motion be- tween the disk and its case. As it is the inner wheel which usually slips when an automobile turns around a corner, the action of the new ball differential is considered an improve- ment over the old type bevel gear. It is being used on a number of cars. oeRn It is divided into one sta- How the Bath-Tub May Be Transplanted or Concealed F the many queer devices that have recently been patented to make the most of the limited amount of space in _ modern apartments, the concealed bath-tub of a resident of Cincinnati, Ohio, is one of the queerest. The ambitious invention provides for “transplanting” the bath-tub to any room in the house, without, so the inventor in- timates, detracting from the general appearance of the rooms. This seems to be especially pos- - sible in the bedroom, for here the tub may be easily concealed at the bottom of _ the dresser or of the chiffon- ier. The dresser is made up into a rather unusual model. tionary part bolted to the bedroom wall, and another movable part mounted up- oncasters. The stationary part contains a mirroranda compartment for soap and other articles. But the mov- able part consists only of two rows of drawers and a wash-basin, for the space Popular Science Monthly 361 A ‘‘Preparedness’’ Sleeping Outfit for the Camp \ ORE and more attractive grows the idea of spending the night under the ' diamond-studded canopy of sky with the untainted ozone saturating the lungs. The principal argument against it is that one is likely to be satura- ted with a less pleasant product of the out-of-doors than fresh air. Rain is the chief foe of the sleeping porch and of the camp, though mosquitoes are a close second. The latest improvement in sleeping bags, however, is designed to rout these foes. It is in use by the United States Marine Service, and it is waterproof, weather- proof and mosquito-proof. C. W. Sirch, of Alhambra, California, is the inventor. The bag is roomy and comfortable, being seven feet six inches in length and four feet three in- ches wide. A hood pro- tects the head, and a netting is attached by special fasteners to keep out the mos- under these must be used to quitoes. cover up the tub. When The disrobing may be done in- To prepare the bag this part is in place against side the bag where there are for use it must be the wall, a pipe leading from pockets for clothing and valuables the water-outlet of the basin comes directly over a catch-basin attached to the bath-tub, so that, by opening the faucets, the water will be directed into the tub. When the tub is sufficiently full, the dresser part is rolled away, and the splashing of the bedroom wallpaper may commence! spread out and a rattan bow adjusted to hold the hood in place. A woolen blanket may be wrapped around the body if extra warmth is needed. There is a pad inside and a bolster, besides pockets in which valuables may be kept. The bag is of felt and is adaptable for use in warm weather or cold. i ae yf < nn 7 f ai £2 i At left, the bathtub is shown in use, the concealing cover having been ondeed aside Gives the tub under the faucets, which are attached to a water-pipe through the stationary dresser-top. At fright, the three parts of the device are united and an ordinary piece of furniture is the result 362 Popular Science Monthly hig A traction wheel and shoe to prevent lateral skidding Combined Brake and Non-Skid Device for Automobiles UPPLEMENTING the action of the brakes and of deformed- tread tires on automobiles to prevent skidding, the non- skid device shown in the accompanying sketches is designed to prevent side or lateral skidding and to check the speed of the vehicle to avoid collisions which might occur if the side-skid apparatus alone were used. The mechanism con- sists of two independent parts, a trac- tion-wheel for preventing lateral skid- ding and a shoe for decreasing the vehicle speed, both parts being forced into contact with the road surface by means of a chain and pedal and a wire and lever controlled from thedriver’sseat. TRACTIVE. BRAKE AXLE CASING ae Light Railroading a Accomplished by Automobile N England motor car railways are fairly common especially where short, light, frequent hauls are the rule and in the United States there is many a suburban line with its self-propelled single passenger coaches. But probably nowhere will you find such a curious automobile rail- road as the one run- ning into Basswood Lake in the northern forest region of Min- nesota. This remarkable little railway sys- tem consists of a converted automo- bile, or ‘‘Lizzie,’’ as it is known to many people. As seen in the accompanying _illustra- tion the automobile has been fitted with railroad wheels, instead of the usual tired wheels and hauls an abbreviated flatcar. It was used on an abandoned logging road making con- nection with the Duluth and Iron Range Railroad. This little road is rich in suggestion to others who may have minor traffic problems in remote regions. A second- hand automobile which could be pur- chased for a comparatively small price would lend itself to the purpose. The railway system consists of a second-hand automobile provided with railroad wheels, which hauls an abbreviated flat car loaded with freight over an old logging road ones ee et lh Ti al da Popular Science Monthly 363 J ar} A New Type of Motor-Truck for Coal Delivery NE of the newest types of mo- tor-trucks has its hydraulic cylinder directly behind the driver’s seat, within the body itself. An- other important feature is that when elevated the body is compelled to remain in a position parallel to the truck frame, even with one end’ empiy and the other loaded. The body is straight-sided and divided into three or more compartments, each with a cone-shaped bottom provided with sliding doors. The body telescopes within a steel framework mounted on the truck frame, and when down the body is flush with the top of the frame- work. When it is forced up by means of the hydraulic cylinder in the center, it is kept parallel to the truck frame by means of eight racks, two at each corner, which mesh with eight rack- pinions on four shafts on top of the frame- work. . eaee 9 ~ f — =~ oe A new compartment motor- truck with its hydraulic cylinder directly back of the driver’s seat - Another Addition to the Motor- Bicycle Family HE latest development in the mo- tor-bicycle is the perfection of a motor-wheel which may be attached to any bicycle, whether it be a man’s, a woman’s or a juvenile model. The attachment consists of a heavy twenty- six-inch bicycle wheel incorporating a two-horsepower plant and fitted with a substantial mudguard designed to fit into the forks of any bicycle after the original wheel has been removed. Although the wheel has a motor which has power enough to climb the steepest grades, the weight and vibration are taken up not by the bicycle itself but by the specially constructed wheel. The bicycle is really converted into a spring- frame machine. The motor is placed on the left side of the N wheel in such a manner that it comes outside the rear fork stay of the bicycle when the wheel is in position. The crankshaft extends straight through the hub of the wheel and is mounted on the other extremity. A high- tension magneto is built into the flywheel. The position of the crank- The bolts which hold the wheel to the rear fork stem-ends fit on a pair of collars on which the power plant is pivoted shaft is the novel feature of the device. The Latest Automobile Improvements Include : } : ) y A trunk for the automobile running board. : 7 It has four suitcases which fit snugly inside at ° At left: A pneu- At right: A new matic tire casing spark plug which combined with a gives an _ infinite solid truck tread is number of sparks. solid yet resilient Above appears me- 4 thod of sparking 4 a f ; . . . . A A trained chicken which jumps up on : the bumper every time the car is 4 taken out. She made one trip of 7 264 miles, going 30 miles an hour 3 ; p : 7 A herculean job for . the motor-truck— 7 moving an immense : silo. Note the ex- tended wheelbase 7 . 3 F 5 BS - ; q Zz = ele ee a Greater Working Capacity for the Truck — Although heavily loaded itself this truck pulled a ship to its launching place with ease. A special trailer carries the ship eS ee BSA GUE eRe aN Above: A tire pump that works by foot-power instead of by hand-power. Press the foot down and the tire is inflated ORT ee Va Ek TNE Eo eee eT " i To the right: A mirror attach- ment by daylight and a search- light at night. The mirror is attached to the searchlight casing Below: A steering-wheel muff for protecting the hands in cold weather. It has two openings and is easily attached or detached YS ION: LARS adore SOMALI Te ee ONE si ata VOCE are. A new side-curtain equipment which Opens with the doors. ~It enables Passengers to get in and out of the car without bending over or unfastening the curtains when they are in use 365 Man’s Invisible Friends They were no more created to do us harm than were other forms of plant or animal life. If they had their choice they would never enter our bodies at all By R. L. Kahn E and the bacteria are WV close neighbors. Our homes are their homes and wherever we go, they go. But alas! How we misunder- stand their purpose. Not long ago, I heard a lecture on these neighbors of ours. The speaker discussed a number of diseases in which bacteria play a part. I do not recall the details, but the impression left I remember well. It was that bacteria are our worst enemies. It is well to emphasize the relation “ bacteria to disease, but it is important that their relation to health be emphasized also. Their purpose seems to be not to cause disease and death but life and health. Remove bacteria from the world, and life might soon cease. Let them stop work, and plants and animals might starve to death. Perhaps no other organisms play a more important role in the evolution of plant and animal life than bacteria. It seems truly inconceivable that organisms so minute should be capable of bringing about such profound changes in every phase of life. Tasks which the greatest chemists cannot perform they carry out with ease. What Bacteria Do for the Farmer The study of modern agriculture is largely the study of the bacteria of the soil. Decaying organic matter in the soil is transformed into food for plants by bac- teria. Three types of these organisms supply plants with nitrates. One type transforms organic matter into ammonia, another changes the ammonia into nitrites and still another changes the nitrites into nitrates. Such is the division of labor that each kind of bacteria attends to its own specialty. One of the products of decay is a gas- sulphuretted hydrogen. The sulphur bacteria decompose this gas and store up free sulphur in their own bodies. But the and Foes supply of sulphuretted hydrogen is soon ex- hausted. The bacteria perish and free sulphur is liberated. Ultimately we get sulphate of lime, an important constituent of plant food. There are also bacteria which supply plants with iron, and count- less others which help in one way or another to make plant life possible. If it were not for bacteria, the world might be piled up with dead plants and animals. Bacteria are the scavengers of the living world. As soon as the life of an animal or plant ends, bacteria gather around it, take the body apart, and reduce it to the elements of which it was originally built. This inherent power makes bacteria per- petuators of life. Matter, we know, is indestructible. The elements which go to build up an animal or plant are not in any way affected when the animal or plant dies. Let these elements be set free, and Nature will utilize them for the construction of other: living bodies. To bactéria it is given to supply Nature continually with elements so that she may always build new living structures. Are Bacteria Necessary to Health? Whether or not health is possible with- out bacteria is to-day one of the most interesting problems in the field of biological science. The question is far from settled. Nuttal and Thierfelder, two well-known scientists, believe that it is possible for animals to live and retain their health with sterilized air, food and _ water. famous experiments carried out by Cohendy and Wollman at the Pasteur Institute, Paris, also seem to indicate that animals 2RR Some Pe eee ey ee) I Se ae Ie Sim Popular Science Monthly can live under sterile conditions, i.e., in an environment entirely free from bacteria. There are, on the other hand, a number of investigators who believe that bacteria are necessary to the development and health of animals. Madame Metchnikoff studied the development of tadpoles, some of which she kept under sterile conditions, | while others she allowed to develop as they do in Nature. After a certain time, she found that those which she kept under ordinary conditions of life weighed six times as much as those which she kept under sterile conditions, which apparently proves that tadpoles can not enjoy the best health without bacteria. In recent years, bacteria have also been used as curative agents. Metchnikoff’s Bulgaricus bacilli, when taken. internally, prevent the propagation of harmful bacteria in the intestines. The bacteria which cause intestinal putrefaction can thrive only in an alkaline medium. The Bulgaricus bacilli are acid-producing bacteria. Their Above: A view of the entire apparatus de- vised by Professor Michel Cohendy for experiments on animal life in a sterile, bacte- Tia-proof environment At right: A chick that has served in the ex- periments. The chicks kept under absolutely sterile conditions lost twenty percent of their weight in five days Below: Placing the sterilized eggs in the germ-proof incubator where the chicks for development under absolutely sterile con- ditions are hatched 368 acid makes conditions unfavorable for putrefaction. Hence the putrefaction bac- teria ultimately perish. How Bacteria Develop by the Million Bacteria themselves, we must Bs do not know the importance of the position they occupy in the economy of life. All they care for is a warm place and a square meal for themselves and their young. And the young multiply rather fast. An average bacterium will divide in two in fifteen minutes; in half an hour there will be four, and in an hour as many as sixteen will be clamoring for food. The number of off- spring at the end of a few days, if not checked, runs into billions. Add to this the fact that there are countless varieties of bacteria, because of the many different functions they have to perform and that these are present wherever there is plant or animal life, and we can appreciate how infinitely large are their numbers. But of all the bacteria which surround us, only those few can do us harm: which grow in the body tissues and enjoy a meal at the body’s expense. Some of these will, from time to time, work their way into the tissues through a cut surface. In ninety- nine per cent of cases, these will not disturb our bodies in the slightest degree. The body fluids take care of them so quietly and effectively that we are not aware that harmful bacteria have paid us a visit. Should, however, unusually large num- bers of bacteria enter our bodies, and what is more important, should our resis- tance be at a low level, due perhaps to overwork or worry, they are likely to cause considerable disturbance. But many years of con- tact with bacteria have ad- justed our bodies so that they can over- come these or- ganisms with comparative ease, even after From their hospital beds the young men conduct a magazine agency with branches in two cities and do their own advertising Popular Science Monthly numbers of them have'gained entrance. The entrance of these enemies causes the body to mobilize at once its defensive forces. Blood, lymph and white blood cells are sent to the spot where the bacteria entered, and because of this accumulation of fluids, that part is inflamed. The body often builds a wall around the infected area to prevent the bacteria from spreading to the surrounding tissues. The white cells now proceed to digest the bacteria. In the course of this process, they digest also the tissue which the bacteria fed upon and thus rendered useless to the body. The infected area—bacteria and all—now begins: to soften. Pus, which is the product of this digestion, consisting mainly of digested tissue, dead bacteria and also dead white cells which gave their lives in this encount- er, isformed. Ina short while, the infected area is clean and healed. Thus the harm- ful bacteria are invariably routed from normal bodies. Conducting a Thriving Business from Hospital Beds WO young men, H. K. De Prez, of Shelbyville, Ind., and E. L. Smith, of Montreal, met over the telephone in Mercy Hospital, in Chicago. Both had been athletes and had received injuries in sports. A friendship began and the young men arranged to occupy the same room in the hospital for the sake of companionship. As their health improved games of chess failed to fill up their days and the natural craving for something worth while to do became irre- sistible. As a re- sult the firm of De Prez and Smith, Magazine Agency, was formed. Typewriters were installed at their bed- sides and a business was started. They sell ENCE MONTHLY and other mag- azines. profitable Tee ee PoPpuLAR SCI- “= Night Mail: A Flying Dream to be Realized A letter mailed in New York at night wiil reach Chicago the next morning mn Wis big If searchlights of about eight thousand candlepower equipped with acetylene gas tanks were used at each emergency station, the pilot would not be likely to lose his way HE day is not far distant when you may drop a letter down the chute in New York and be confident of its delivery in Chicago the next morning. The flights of Ruth Law and Victor Carl- strom have afforded ample proof that a New York-Chicago mail service by aero- plane is feasible. The Post Office Depart- ment is actually considering an air-line mail-service between the two cities. It is estimated that the trips can be made in from six to fourteen hours, depending upon the wind, and that the average flying time for the seven hundred and twenty miles will be eight hours. The distance by rail is about one thousand miles. Definite plans for the maintenance on a regular schedule of this air trunk-line for the mail have been proposed. One plan involves emergency stations every twenty- two miles, each equipped with powerful lights. In addition, two landing and one relay station are also planned. The aero- planes would leave the two termini at six o'clock in the evening and deliver the mail before nine o’clock the following morning. Under the most favorable conditions it would reach Chicago by midnight. Leaving New York at dusk, the aeroplane mail-carrier would follow the lights at the emergency stations to the first. landing station, which would be in the vicinity of Williamsport, Pa. There, at a flying field equipped with hangars, tools and -spare parts, he would stop for oil and ‘gasoline, and would then continue to a relay station near Niles, Ohio. Here another machine would finish the flight, landing near Napo- leon, Ohio. Powerful searchlights would mark the emergeney stations and _ special lighting systems would illuminate the flying fields, even: in foggy weather. 369 William A. Sharpe in his motor goose which is a com- bination automobile, motor boat and flying machine be in motion. Therefore a prelimin- ary run upon the ground is necessary. Hence, every aeroplane is virtually an automobile and could be used as such if our roads were wide enough to accommo- date its wings. A hydroaeroplane is a flying machine which takes its running start on water. Hence, it must be a service- able water craft. Is it not possible to build a machine which will be automobile, motor boat and flying machine in one? William A. Sharpe, of Detroit, thinks so. It is not a new idea to build a floatable automobile which can run into a river from the shore withoutastop. But it is certainly a new idea to combine in one vehicle the properties of an automobile, a motor boat and a flying machine. Bi ORE an aeroplane can fly, it must The Motor Goose She runs on the ground; she swims in water; and her inventor says she will fly By Carl Dienstbach doubtedly take up much less room than ordinary aeroplane propellers. By a simple adjustment of the me- chanism that controls the feathering, they can be made either to lift or propel, or perform both functions to a varying degree. To maintain the balance of the craft in flight, seems theoret- ically easy; for the lift at each of the four supporting points may be increased or reduced at will as the occasion may demand. As the boat, automobile, or flying ma- chine, whatever it may be called, is driven over roads or water, the lifting effect of the propellers would undoubtedly be conducive to high speed. But, can the propellers support a machine in the air? If you will study the accompanying photographs you will see that no supporting surfaces, such as wings, are provided. How then can the machine fly? Perhaps you have seen a little toy which consists essentially of a horizontally mount-. ed screw-propeller driven by a rubber band. When you tighten up the rubber band and Mr. Sharpe’s ve- hicle has a boat body which is mounted on regulation auto- mobile wheels, which is equipped with a rudder, and which is propelled by four air propellers. These air propellers are in reality feathering paddle-wheels such as have been often proposed for air craft. Benbow used them on the dirigible with which he flew over the St. Louis World’s Fair in 1904, for example. ‘| The ordinary. air propeller is usually mounted on an aeroplane at the rear or in front. Mr. Sharpe would mount his pro- pellers as the paddle-wheels of river steamers are mounted—that is, flat along the sides of the craft. In that position they un- wings. release it, the propeller literally kicks the little toy up into the air. Such a machine is known as a heli- copter, or screw-flyer. ever been built biggér than this little toy— that is, a helicopter that will fly. Mr. Sharpe intends to rely upon the There are no supporting surfaces, such as The machine would mount into the air by the helicopter, or screw-flyer, principle helicopter ‘principle in order to get his machine into the air. Unfortunately, his propellers are smaller than those of a helicopter’s of equal size. Even if they were of the right size and even if they were mounted horizontally like those of a true helicopter, it is doubtful if he would get off the ground. Only one of the blades of his propellers is effective at a time, just like the paddles of a river steamer. To get a substantial lifting grip 3270 No_ helicopter has © FT A EN ee ee -nheuver in playing golf— _ Stationary until the on the air, the propellers would . have to be very strong and the motor by which they would be driven would have to be very light. Their speeds would necessarily be enor- mous. How much additional support the propellers might gain gratuitously by moving ahead and always working in fresh undisturbed air, has never been discovered. Too little is known of helicopters to settle the matter. At very high speeds fly- wheels often burst because of the enormous centrifugal force developed. At the high speed with which Mr. Sharpe would have to run his propellers in order to get into the air, equally great centrifugal force would be generated, particu- larly if all the delicate feather- ing mechanism must be exposed to them. Lastly it is to be noted that the front paddle-wheels leave a wake which must be disturbing to the rear pair. Let This Machine Teach You How to Play Golf ID you ever see a golf coach made of iron rods, a few screws, and a leather pad? If not, look upon the illustration of one invented by Hugh M. Rhind, of Chicago, Illinois. A perfectly good coach is the iron contrivance; for it is warranted to teach the most difficult and most important ma- the perfect “driving” of g ¥ the ball. The secret of the re- markable way in which a real good golf player drives one “great’’ shot after another is to be found in the fact that he performs the same move- ments for all drives. He has found from experi- — ence that, forinstance, by keeping his head ball is driven from the tee, and by keep- ing his arms at a certain definite Popular Science Monthly A close-up view of the proposed machine. The device keeps the golf player’s head and shoulders level in order that a correct sight may be readily obtained The propellers would have to be very strong and the motor light to lift it extension and level, he will hit the ball efficiently. Evidently then, it will be necessary for him only to repeat exactly these same movements, and the next time he will make the same wondrous shot, to the great amazement of the onlookers. It is on just this simple principle that Rhind’s invention works. It teaches a man to keep his head still during the downstroke of the drive. The leather pad fits comfortably over one side of the player’s head. The iron rods hold the pad firmly in place, and the screws allow the pad to be adjusted to fit persons of various heights. The player-to-be plants his head firmly against the pad, and not until he has struck the ball from the tee does he remove it to lunge his body forward. His head and shoulders will then have been kept in the exact position for a perfect sight and a good stroke. After the be- ~ ginner has studiously practiced with this de- vise for several suc- cessive rounds of the links, he will be far on his way towards becoming a star in the sport. 372 Popular Science Monthly Making a Stage Ocean with Green Silk and an Electric Fan TTEMPTS made to devise apparatus by which the effect of a heavy sea can be obtained on the stage without actually employing-water have been somewhat un- successful. Ordinarily a large canvas is employed, painted to represent waves and moved by machine or by hand beneath the canvas. Stereopticon pictures and colored lights have attached has beem employed to generate the electricity. William H. Chapman, of Portland, Maine, applies the contact prin- ciple of the iron pulley and belt instead of the principle of friction in static gene- rators. In his machine’ the usual friction pads give place to a trough of mercury, analogous to the iron pulley. Not only is an unpre- cedented mechanical efficiency obtained but — from an elec- been utilized to make the effects more realistic. All these at- tempts have not only been expensive and cumber- some but have proved unsatisfac- tory. They lacked real- ism. Ida May Fuller, of New York city, has obtained satisfactory results on the stage by means of an openwork support, preferably of light, white netting, to which is attached in festoons on the front side a fabric such asa fine translucent silk, which reflects light and which is of such texture as to be easily waved back and forth by an electric fan or by hand. . Water-green colored silk produces a sat- isfactory illusion, without any external lighting effects, regardless of whether the motion of the waves is made by stage hands moving the support or whether an electric fan is used. When it is desired to show figures or objects beneath the water the figures are placed beneath the projecting light and behind the support. A Frictionless Contact Generator of Static Flectricity HEN two dissimilar substances are pressed together and then separated, one acquires a positive charge and the other a negative charge. A leather belt running on an iron pulley is an illustration of this. The belt: acquires a negative charge at the point of separation from the pulley and the pulley a positive charge. Hitherto, with static generators, a mov- ing plate of glass with frictional rubbers by wire netting and waved by the air currents from the fan trical stand- point the high po- tential effects are ofan order not heretofore attainable with friction apparatus. Aglass plate making eighty complete rev- olutions a minute and dipping into a mercury trough to a depth of one and one half inches, without induction plates, will develop a potential of 9,000 volts on comb points, arranged to collect the charge at the top of the plate. induction plates close to the revolving plate, at the point where it leaves the mercury, raises the potential to 13,000 volts or more on the comb points and gives sparks three- quarter inch long. This is still further- increased by covering the induction plates with a thin sheet of rubber or glass. Sy CHARGE COLLECTING TEETH = eS ROUNDED TO PREVENT BRUSH DISCHARGES Y PULLEY- br INDUCTION PLATE FOR KEEPING DISC DISCHARGE LOW NEAR MERCURY MERCURY ae oe CONTACT TROUGH In this machine a trough of mercury is employed to generate electricity by contact eight inches in diameter, The application of. ee ee Making a Fortune out of Tears The Story of a Child’s Toy By Harold Cary N 1904 Clarence White, of North Ben- nington, Vermont, was doing a large business in stereoscopic photographs and stereoscopes. He had more than four hundred agents on his list. Sales amount- ed to about half a million a year. Business was so good that a hundred thousand dol- lar-addition to the factory was made. Then, in 1905 the motion picture came. The stereoscopic photograph industry col- lapsed. Said The construction .of the little cart is youngster who lived next door had seen the cart and coveted it in the Biblical way, which means that he took it. The neigh- ' bor’s wife brought it back in the evening and made the White boy happy again, but she explained also that her Crown Prince : __ would be un- controllable until he had one like it. He got his cart, too. So did half a dozen other young- sters who lived nearby. A home demand was created. White began to work at the problem of giving the boys of the nation the boys of the simplicity itself, but it pleases the lager a © ountry: youngsters, so the production is rapidly e nad made Why should approaching thirty-five hundred a day for Benning- we look at ton. stereoscopes when we can see motion He took out patents and made a dozen pictures?” carts to be tried out as samples in New Clarence White started to hunt for something new to manufacture. Toys of various sorts were tried out. They had a good sale only during the months preced- ing Christmas. Discouraging conditions continued until 1915. In the Spring of that year Clarence White came home one day to find his two and a half-year old son in tears and his mother discouraged. The youngster in- sisted on riding his toy cast-iron fire- department equipment to destruction. He had already smashed the hose cart. The tears were caused by his mother’s refusal to allow him to break down the fire engine moe... “Never mind,” said father. “‘I’ll build you something that you can’t break.” The next night Clarence White brought home a little three wheeled cart made of a board, an upright handle and wooden circles cut from another board. But the trouble had only begun. The York. These were placed on the floor in a New York department store. While they were being unpacked one Saturday, a woman from Plainfield, New Jersey, saw them and carried one home. On the following Monday morning half a dozen Plainfield mothers trooped in for carts like the one they had seen. The entire shipment was sold during the day and the toy buyer put in an order for ten gross. Bennington was on its industrial feet again. Mr. White’s father is a splendid old-time mechanic. To-him was entrusted the task of providing machines that would turn out the little carts automatically. In a few months the output had risen to fifteen hundred carts a day. At no time has production caught up with demand. The first profits, amounting to one hundred and twenty-five thousand dollars, were put back in the business to buy machines. On September 4, 1916, production had increased to twenty-five hundred a day. 373 374 Popular Science Monthly The tank holds nearly two thousand gallons of water and is designed to withstand a pressure B of forty-two pounds to the square inch. On account of the high pressure less water is needed New York’s Wonderful Street-Sweeper and High-Pressure Flusher HE New York city street cleaning department, tired of waiting for in- ventors to turn out an efficient cleaning machine, put its own electrical and me- chanical engineers to work on designs. The new cleaner they devised is almost completely electric. | Every wheel is turned by motor power. ‘The current is generated by a dynamo which is driven by the gasoline engine under the hood. Two motors turn the driving wheels, one the broom, another the atomizer pump and a third the flushing pump. The driver of the truck handles his gasoline engine and steers the machine, all other work being done by the flusher who has a seat on the rear of the trailer, at which point all the controllers for the various de- vices are located. The machine is capable of cleaning from one hundred to one hundred and twenty-five thou- sand square yards of paving per day. It can scrub a street which is thirty feet from curb to curb in two trips. As it moves at a speed of from nine to nine and a half miles an hour it can clean fifty miles of street in a single ten-hour night. Utilizing the pressure system of flushing makes it possible to clean the streets as carefully as a ball room floor. The tank holds 1675 gallons of water. STEAM | CHAMBER PERFORATIONS AND TUBING FOR CIRCULATION The radiator boot is con- nected to a hot water supply in the same way as is a steam radiator Your Feet Are Cold? Then Use the Foot-Radiator ‘ROM West Virginia comes a new. application for hot-water and steam — heating. The inventor has designed a boot on the style of a foot-radiator. It consists of an inner water-tight stocking of rubber and another stocking surrounding it. The space between the two is sealed from the outside except for two openings, one through which hot water or steam is to be supplied to fill the opening, and the other through which the cooled water and the used steam are to be ejected. There are two ways of supplying the hot water or steam. One is to attach a hose to each opening and connect it with a source of hot water in the same way that: boilers are connected in a heating system; the other is to fill it as you nipple would a hot water bottle. The - inventor makes the claim that the device may be used by attaching it to the exhaust of an automobile engine. Just how the inventor in- y tends to carry off the exhaust gases nipple after they have been admitted to the boot he does not say. Evidently _ the thought in his mind was fivner to provide an outlet for the STOCKING —___ purpose on the outer side Niinine’ Of the boot, or through the y ejector hose. Some kind of a control arrangement would have to be provided, also, to pre- vent the boot from becom- _ ing uncomfortably hot. STEAM PIPE Se The Way of a Bird in the Air A gigantic artificial dove and the lesson that it teaches ORE than twenty years ago, Otto Lillienthal, a German engineer, be- ™ came interested in flying. He was one of the first scientific pioneers of the aeroplane. For weeks and weeks at a time, he would watch storks in motion. To him, birds were masters from whom ignor- ant man must learn if he, too, would fly. Lillienthal’s first step, after long watch- ing was to build a motor-less machine of a to the air, and that, after all, the bird idea was inherently correct. All the latest machines look very much like birds because they have been provided with bird-like bodies in which passengers and engines are carried. A New England inventor, Percival White, has very wisely taken up Lillienthal’s line of investigation and has built an exact gigantic copy of a carrier pigeon. His glider is an object lesson. His huge bird shows how sweet are the lines of Nature’s flying machines and how Garcvel White’ $s gigantic copy of a carrier pigeon. It has landing skids under the body and a drag post under each wing for easy alighting. The wings are pivoted and swing easily type which has since come to be called a glider, a kind of artificial bird, consisting primarily of a pair of canvas wings stretched onaframe. He would run down a hill with this apparatus. After he had acquired sufficient momentum, he would draw up his legs, glide along freely for perhaps a hundred yards, and come: to earth. This performance was not so easy as it seems. Even on the calmest days, the wind tended to upset his apparatus. Lillienthal had to throw himself bodily from side to side to maintain his balance. He had to be very quick—just as quick as the wind. He made many hundred flights and learned.a great deal about soaring. But one day, he was not quick enough. The wind upset him, and he was killed—one of the first martyrs of the air. When the motor-driven aeroplane at last came, inventors paid less and less attention to birds. The construction of flying ma- chines was reduced to a problem in engi- neering. And so the aeroplane became less and less bird-like. In the hands of Wright and Curtiss it assumed the form of a box- kite with a man and motor perched on the lower edge. Soon it was found that such a construction offered too much resistance well worth copying they are. Although he may not have had it in mind, young White has vindicated Lillienthal. Every aero-- plane designer must envy the modeling of White’s glider. Lillienthal took great pains to explain that if a bird is merely copied and enlarged, it becomes either too heavy or too weak to fly. This is a matter of structural size and strength. How White has made his arti- ficial dove strong and light enough to serve as a gliding machine without prominent stay posts and wires remains a question. But even if White’s glider serves no other purpose than that of setting the flying efficiency of a bird’s shape into bold relief, it is worthy of all praise. Assuming that the structure is strong enough, the flat gliding angle and the perfect shape of the body would insure efficient flight. Like Lillienthal, White must throw his body from side to side in order to balance him- self. But balancing in this fashion ought to be easy for White. Lillienthal himself pointed out that a bird easily shifts its weight or rather muscular effort (the same thing in this instance) to both wings or fore and aft in order to control itself side- wise and lengthwise —CARL DIENSTBACH. bo ty A= Hell. Swazey Breaks up the Dance A true dynamite story which shows how an im- portant fact about nitro-glycerine was discovered By Hudson Maxim This story, which tells how the fact that nitro-glycerine can be made safe simply by freezing it was discovered, is taken from Hudson Maxim’s recently published “Dynamite Stories.”’ printed on page 321. The author’s impression of Popular Science Monthly is He is the inventor of the smokeless powder used in the navy, one of the foremost authorities on explosives in the world, a distinguished inventor, and a prominent member of the Naval Consulting Board.—EDITOR. BOUT the first use of nitro-glycerine in ' the United States as a blasting agent on a large scale was in the construc- tion of the Hoosac Tunnel in Massachu- setts, on the Boston and Albany Railroad. A chemist by the name of Professor Mowbray believed that the main trouble with nitro-glycerine had been that it was not sufficiently purified in its manufacture. He induced the builders of the Hoosac Tunnel to try his product. He put it up in tin cans, which held about a quart. carefully packed in cotton flannel. The method of using the dynamite was to pour it into holes drilled in the rock, inserting an exploder cap and fuse in the _usual manner. At that time it was popular- ly supposed that if nitro- glycerine or dyna- mite were allowed to freeze, it became very highly sensitive and would explode on the slightest jar. Stories were prevalent that the sound of a fiddle would explode it. One day there came an urgent call from the east end of the Tunnel for more nitro- glycerine. Professor Mowbray had in his employ a care-free and fear-free fellow by the name of Helton Swazey. When Swazey was sober, he was the soul of good nature, but when drunk, which was very frequently, he was as savage as a hungry cougar. This peculiarity earned Helton Swazey the nick- name of Hell Swazey. It was avery cold winter day when the call came, and Professor Mowbray, learning that Hell Swazey was going over the mountain that very evening to attend a dance, asked him if he would not take over the nitro-glycerine with him. A hot-water bag was placed with the nitro- glycerine and all was wrapped in a heavy blanket to protect it from Jack Frost. The shipment was placed in the back of Swazey’s sleigh. For transportation these were His best girl, whom he took with him, did not know the nature of the cargo. _ The nine-mile ride over the mountain was very cold. Swazey kept himself warm by imbibitions from a flask of liquid caloric, and to keep the young woman warm he took the blanket and the hot-water bag from the nitro-glycerine for her comfort, leaving the explosive to the mercy of the below-zero weather. When Swazey arrived at the dance-hall ‘to join in the frolic, he was in so ugly and meddlesome a mood that he was promptly put out of the hall, followed by his woman companion. Swazey was mad all through. He went to the sleigh, and taking an armful of the cans of nitro-glycerine, returned to the hall. Opening the door he proceeded to hurl them at the merrymakers. . One can struck upon the stove and glanced across the room. Cans smashed against wall, ceiling and floor. When Hell Swazey turned up for duty the next morning, Professor Mowbray had _ already heard of the escapade, but he was filled with marveling why the nitro-glycerine had not exploded, particularly as it must have been frozen very hard. When Swazey entered the presence of the Professor, he expected to be discharged. To his amazement, Professor Mowbray appeared to be very much interested and pleased, tapping his forehead with his finger, smiling and nodding and muttering to himself, ‘“Good; good; splendid!” He interrogated Swazey carefully, to be assured that the nitro-glycerine was frozen hard, that it had been thrown hard, that it had struck hard, and that it had not exploded. That very night there was mailed at the North Adams Post Office an application for a patent for freezing nitro-glycerine to make it safe to handle. 376 “"Threw Me Out, Did Ye? Then Take That and That!” When Swazey was sober he was the soul of good nature, but when he entered the dance-hall he had imbibed such a quantity of fiery spirits that he was as Savage as a cougar. So they put him out. In the truck outside were the cans of nitro-glycerine—handy missiles with which to “get even.” But kind Providence foiled the plan. The explosive was frozen A Touring Triplane for Ruth Bs A new world’s record is now in order Wires are not entirely absent from the construction of the machine. But they are so few in number that their effect will be negligible. little for the resistance offered by the air. They were glad enough to fly at all. Wires and struts were used with no re- gard whatever for their retarding effect when propelled against the air at railway speed. The aviator sat on the lower edge of a biplane so that his ‘Tie early builders of aeroplanes cared Resistance has been reduced by eliminating the rear struts also meant much head-resistance. It is true that the resistance is increased. But if structural difficulties are overcome, wire stays may be abandoned without at all weakening the craft. Recently a triplane without wire staying broke the speed record of monoplanes—an achievement which would have been consid- body added its re- sistance to that of numerous projec- tions. No wonder that monoplanes were swifter. Soon aeroplane builders discovered what they should have known in the very first place—that it is easier to move a large, correctly de- signed bulk through the air than a multi- tude of projections each of which rakes the atmosphere and leaves a little wake of its own behind it. As a result the avia- tor, whether he mounts a monoplane or a biplane, is now completely enclosed in a kind of boat-body so shaped that it parts the air easily and leaves a comparatively quiet wake at the rear. In the early days of the aeroplane, it was thought that the piling of surface on surface, while it meant stability in flying, The boat body is so shaped that it parts the’ air easily and leaves a quiet wake behind ered impossible only five years ago. The performance of that triplane served to drive home the les- resistance which counts for everything in attaining speed. it naturally followed that a touring tri- plane like that of built. - Study the photo- graphs of Miss Law’s machine. Wires are ~ not entirely absent. They are necessary because of the ma-. chine’s size. Still they are so few in number that their effect must be almost negligible. The rear struts have disappeared with the result that useless resistance has been much reduced. Plucky Miss Law, who accom- plished so much with an antiquated type in flying from Chicago to New York, should do great things in this modern machine. oro 7 i at lies Pe ee honed son that it is head-— After that success Miss Law should be a Na I PONT ———t et A Terrible to the Eye Alone A boy’s bean-shooter can do more harm than one of these stage guns, despite their formidable appearance abe: big Bertha and all the other members of the Krupp gun family stand a fair chance of being out-Krupped if our enthusias- tic motion-picture producers continue to copy faithfully the outward appearance of Germany’s modern ordnance. In one of our latest celluloid thrillers, depicting the capture and ruin of this country by an invading force, Krupp guns— or at least their wooden coun- terfeits—are utilized so real- istically as to lead the audi- ence to surmise that the Kaiser chartered a tug boat and scow to ship his Krupps over the sea for just one motion-picture play. The fact is that the office boy with his bean-shooter can. do more damage than a dozen such “stage’’ guns. But for motion-picture pur- poses these wooden counterfeits are just as effective as the real article. To.see them roll up some peaceful countryside followed by a horde of warriors and to see the big make-believe monsters boom away at an invisible enemy is just the next best thing to seeing one of the Crown Prince’s armies batter away at the French. The effect is start- CYLINDER IMITATION (COMPRESSION CYLIN The stage guns not only simulate the outward appearance of the Krupps but even their recoil movement at the moment of discharge of a modern highpower gun in action. For instance, a powder charge is exploded to represent the discharge of the genuine gun. The charge is ignited by an electric circuit. At the instant of powder discharge the gun barrel moves freely down in its frame. In its downward move- lingly realistic. The principle feature about these guns which makes them simulate the ‘real Krupps, is their ability to imitate the natural recoil at the mo- ment of discharge, and the gradual raising to firing position. Each gun is provided with ' mechanical means which give a real- istic representation SUDING ROD fay Yj LATCH, WY, a, li yh \\ Wy \) , ELECTRIC CIRCUIT TABLISHED WHEN Bee... oa WH WY (FU. ai ATCH 1S PULLED BACK ROPE TAUT WHEN BARREL RECOILS yf //, Wy Nj Ws OF BARREL STRIKES TRIPPER Diagram of the interior of the wooden gun. The charge of powder is ignited by an electric circuit 379 GUN BARREL CYLINDER ment a spring is compressed, giving the cushioning effect of the com- pression cylinders of modern guns. The gun barrel weighs four hun- dred and fifty pounds. In order to move it back again to its original firing position a counterweight of five hundred pounds is released by a lever. HOLLOW RUBBER New Kinks and New Tools Which Have Been Lalla Below: The “sucker” prin- ciple utilized in gripping weights. After creating a vac- uum the hollow rubber cups stick tightly to the weight _ AIR ae PASSAGE EGY = hiiuieniianiceasce ee VACUUM CUP a Feeling the pulse of steel with a hollow rod, on one end of which a meter is fitted to gage the temperature. When the dial needle touches a red mark the critical point has been reached CLOSED A valve and cock which not only controls the amount of gas but the amount of air feed to a stove The flexible carrying bar mounted on a tripod is the latest device for hand- ling tools, rifles and machine guns Below: A screw- driver which is pivoted to its handle. It can be used in the usual straight position or in the “T” position, as illustrated ee ee aT Pr es oe eee Fe ee ee eT ee am saad ; * § . 2 * a : ce fe enn We Gre + ne cut: Sai * ~ ee eee Placed in the Hands of the Mechanical Workers Above: A soldering apparatus in which the current employed passes through the sol- der being used. The circuit is broken when the solder is removed so that none is wasted Below: Flexible sheet- metal belting made up of a series of sheets linked together. They are easily detached On the right below: Straight-grain grind- ing done by laying the work lightly against an endless band of abrasive cloth 381 = At left: A machine- tool which cuts dupli- cate keys from originals in a minute or less. The key to be duplicat- ed is placed in the lower vise and the blank key in the upper vise Below: A tool which can be adjusted to cut round holes of various sizes. It is operated by a_ ratchet-wrench A six-pronged rack which enables a man to elevate a barrel in three different po- sitions for drawing the contents. It is also used in loading and unloading freight OPERATING HANDLE GUARD IN INOPERATIVE Y* GUARDS IN OPER- POSITION ON STREET ATIVE POSITIO LEVEL CURB ont oh N TROUGH The Automatic Traffic Controller. No Law-Breaking Speeder Can Escape It oS. drivers who use the city streets for a race course would find their riding rather rough if the streets were fitted with John J. Keenan’s traffic controller. It is guaranteed to stop in re- cord time any driver who is trying to defy the speed laws. The device, as the illustration shows, embodies a series of short steel arms which are fitted across a narrow trough in the ground. The arms, strung one after an- other across the corner of a street, con- nect at ,the bottom ,with a long bar. This bar can be worked back and forth within the trough by means of its gearing connection with a turnable upright post. Through this bar, the arms can be made to turn around until they project above the street when the post is swung around in one direction. When the post is swung in the opposite direction, on the other hand, the arms are turned downwardly until they are flush with the level of the street, thereby closing up the trough. : An elaborate electric signaling system connects each post with all the others that may be placed at the important points along the main highways. Should a party _ At left is a diagram that explains the operative principle of the device. In the picture above the policeman at the central post in the middle of the street has thrown the apparatus into operation of autoists come tearing down the street, the policeman who first sees them signals *ahead to other officers. They in turn throw the apparatus in operation. “Unless the autoists heed the warning to stop, they will find that the projecting arms will have punctured a tire or two, or will have ripped off some of their mechanism. If the police- man should have deemed it necessary to telephone all the stations in the city to be thrown in, there would be little chance for anybody to get away. Grafting with Frog’s Skin Gives Satisfactory Results HE idea of grafting with frog’s skin was put into practice as early as 1886. Recently fourteen cases of successful graft- ing were reported in France. The ideal wound to graft is flat, and without excessive granulations. The method of applying the frog’s skin is as follows. cleaned without antiseptics and as gently dried. Then the loose skin on the inner side of the frog’s thigh is carefully pinched up in a pair of dressing forceps, snipped off with scissors, spread out and applied by its under surface to the wound. A strip of gutta-percha tissue is then placed over it and fixed in position at its ends by adhesive plaster. Then a dry dressing is applied over all. rapidity after the grafting. Frog’s skin is used, however, only in places where it will not be conspicuous. The wound is first gently _ The wound hea}s with remarkable — q : of her endurance, kill her legitimate chicks and make life in general miserable for _ do otherwise than they would | _Loaned Mothers and~ Borrowed Off- -- spring in the Animal World TF the wolf that mothered Romulus and * had realized that the two little _ waifs belonged to the tribe of her enemy, _ man,and would doubtless grow up to kill thousands of wolves and probably her- self, would she have nourished them and cared for them so faithfully? Likewise the hen in the picture. She has taken under her wings a litter of pups and is as happy brooding over them as if they were a hatching of blue ribbon chicks. Yet those same puppies will in an inconceivably | 2 short time forget the \ warmth of the sheltering a & Popular Science Monthly 383 The Russian Cow Protects Her Eyes with Spectacles “ERE latest news from the animal king- dom is that ten thousand cows on the Steppes of Russia have been provided with dark glasses to protect their eyes from the glare of the sun on the snow. The only food obtainable in winter is a meager supply of grass which crops above the snow in places where the ground is less deeply covered. i The sun shining on the snow issufficiently daz- zling to cause snow- blindnessand greatsuf-. fering among the ani- mals. An enterprising and sympathetic man designed smoked glasses which could be worn with comfort and safety. These are very similar in design to wings and tease and tor- \ 'y ment the hen to the limit The motherless uae and the chickenless hen are equally satisfied for the time being by the temporary adoption _her unless a kind providence’ in the person of the farmer _ with a stick teaches them to those worn by the mules in mines where sulphurous gases abound. The cows, however, have a curious grandmotherly appearance in their spectacles. _ if left to instinct. _ The question which inevitably arises is “Does the mothering instinct put reason to flight?”’” In this case the answer might be that no one ever “actused the hen of having reasoning powers. In Virginia, _where this photograph was taken, instances are numerous of animosities between differ- ent branches of the animal family being buried for a time _in order that much-needed pro- ‘tection might be given to atte helpless young. TUBE CONNECTING Perhaps the most $7235" ps unusual instance, though, of loaned ma- ternal affection and nur- ture is that of a snake which came regularly to a certain pasture where a friendly cow looked eagerly for it and will- ingly gave of her milk, completely mystifying the farmer who was on the look-out for the milk thief. When the snake was found and killed the cow seemed to grieve as though for her calf. EX Hg i¢ A PURE The comedian will dance to any perforated record you play whether it be a waltz, a minuet or a fox-trot Try This on Your Piano. It’s a New Idea, But Not in Music HE mechanical dancing comedian is familiar to everyone. You wind him up and he does his little best to amuse you by jigging around for a_ specified time. But the dancer in the illustration below is not limited in any such way. He stands on a platform on top of the player- piano and dances just as long as the music keeps up. He will dance anything for which you have a per- forated record, keeping excellent time and step. The secret of the perfect rhythm which he keeps with the music is his con- nection with the bellows m of the piano. The rod “)& which supports him is figs attached to a spring fe, which is in turn fasten- > ed toone arm of the bel- lows. When the piano is ‘‘pumped”’ the bellows move up and down. This causes the come- dian to dancein time with the music. “ear 384 Why Does the Heart Stop Beating at Death? | HE question, ‘‘Why does a man or an animal die?’’. has been answered, “Because the heart stops beating.” But any hunter or fisherman who has dressed his own catch can testify to the fact that the heart does not stop beating at the moment of the animal’s death. Often it will continue to pulsate rythmically for several minutes after it has been removed from the carcass. The most recent answer . to the “Why?’’ of this is that the heart muscles themselves possess the inherent - quality of contraction and will contract, or - beat, just as soon as or as long as the conditions of environment are right. That is their business and they can no more - refrain from doing-it under the right con- ditions.than arose could help giving out its fragance. In recent experiments it has been found that heat is the principal element _necessary to the development of heart muscles and their subsequent action. It is possible to grow the heart muscles of a warm-blooded animal in an incubator. During this growth a single muscle cell has been ob- served to develop and wander away from the mother cell and begin to beat of its own accord. Again, several individual cells may attach themselves to each other in a colony and beat rythmically together as long as the environment is favorable. Popular Science Monthly — But let the temperature of the incubator be materially reduced and the action of. the heart muscles becomes sluggish. Re- duce the temperature still further and gradually the rythmic action ceases al- together. The cells cease to perform their natural function because their environment: is no longer right. In other words, they die because they are cold. . According to 4 this theory, the heart muscles. could live , on independently of a body, if kept at the proper temperature for their-best develop- ment. ee | ee A Land Ride for Whales in South Africa HUGE motor-truck equipped with flanged wheels for use on a standard- gage railroad has come to the rescue of a whaling company in South Africa and has. solved its transportation problem. The whales are carried by truck from the shore and are transported to the factory to be treated for the extraction of oil and other products. The whales are hoisted on the truck by means of derricks and when once in place on the truck body they are securely lashed by chains. The truck is sixty-five feet long. It has a capacity of one hundred and sixty thousand pounds. The six-wheeled sup- ports for the truck body keep the axle loads down to the required limits and insure the necessary flexibility over the railroad line. Transporting whales in South' Africa by means of a special motor-truck railroad car. Whales weighing as much as eighty tons can be transportei in this manner from the shore to the ee ee ee eS ee eee | : : . - Popular Science Monthly 385 The anchored car is raised from the ground, heavy castings take the place of the rubber tires on the rear wheel to give momentum to the gear-shift, and a special mechanism gives warnings Learning to Drive an Automobile in a Stationary Car EARNING to drive an automobile on a crowded city street is a rather nerve- racking experience. A better way is to sit in an anchored car like the one illustrated above, which is an invention of Mr. C. M. Bishop, and imbibe instructions. The first lesson is devoted to familiarizing yourself with the controlling devices of the car, and on this imaginary trip, you are “accom- panied”’ by the instructor. After that you must go it alone, while the instructor stands on the left side of the car and operates a special mechanism by which factory to be treated for the extraction of oil and other marketable whale products he can throw up various precaution signals and produce an effect on the engine such as would be occasioned under certain con- ditions on the road. The signal post, which is placed near the left front wheel is similar in plan to those used in traffic police regulations, except that they indicate “danger,” “‘steep hill,’’ “downhill,” ‘road - closed”” and more difficult warnings as the pupil advances in the work. The instructor, standing beside the car but out of view of the amateur motorist, operates these signals at wheel by means of strings supported by a secondary post. At the same time, he keeps his hand on the principal part of the mechanism, which consists of a lever controlling a strong band- brake attached to the rear wheels. The car is raised clear of the ground so that it cannot move. The rubber tires have been removed from the rear wheels and heavy castings put in their place. This weight gives the same momentum to the gear-shift as would be obtained on the road, while the band-brakes controlled by the instructor operate against the entire surface of the iron tires. The instructor can stall the motor in any speed, and the pupil learns by actual ex- perience what to do in every contingency. It seems reasonable to suppose that the student will absorb the instructions more quickly on account of the elimination of the things that cause nervousness. There are no pedestrians to get under the wheels; no plate-glass windows to loom suddenly up in close proximity; no hills to slide down at breakneck speed and no relentless blue- coat on guard with stop-watch in hand, should the speeds get mixed. A Model Six Hundred-Car Garage bg t Ba Each car has its own stall in the form of an island platform which guides it This eliminates crowding and exasperating delays into or out of the aisle. N the giant garage shown on these two pages, the exasperating delays often encountered in getting cars into or out. of the aisle are eliminated, because the garage has no elevators and the cars are automatically spaced on the floors in such a manner that there is sufficient room for each one to run out into the aisle without disturbing the cars next to it. Inclined concrete ramps take the place of elevators, each ramp being twenty feet wide. They are arranged so that one line of cars goes up while another line is com- ing down. There is a concrete curb in the cen- ter of each ramp, to restrict the lines of cars to separate paths, so as to prevent collisions between cars passing in opposite directions. Besides being a great convenience to the individual automobile owner, these two-way ramps will effect a saving of approximately $18,250 in annual overhead ex- pense for the garage-own- er. The ramps from floor to floor of the four-story structure take up the same amount of room as elevators, but the cost of building them is the only expense connected with An automobile can get into or out of it in from ten to fifteen seconds them. It costs nothing to oper- ate them when once built. The designer of the garage, H. B. Mulliken,of New York city, has calculated that the cost of each trip of an eleva- tor is ten cents : and that the average daily number of cars going up and down in the six hundred-car structure would be two hundred and fifty, making five hundred trips in. all. The delays incident to backing a car into its stall between two other cars whose positions are only approximated by white- wash lines on the floor or numbers on the walls, have been eliminated by the use of island location platforms much the same With a capacity for six hundred cars the new 386 ee eS PE ee pe Bi a isl a Esper? So CE SGN Ta cis) ee ee ee ae ee ee ee ’ in curved end of the serves to guide the PPAR ee Binks re ee eee as the isles of safety for pedestrians in our most-congested city thoroughfares. _ These island platforms are a special feat- ure. Each car has its own island platform, which is made of concrete, integral with the floor. Each platform is ten feet long, forty-nine inches wide and four and one- half inches high, with a rounded, but slightly pointed end facing the aisle. The cars are arranged in two long rows with an open runway between for entrance and exit. Aseachcarenters theaisleitis backed up~ until its rear wheels strike the platform. This vehicle automatic- Popular Science Monthly 387 The island platforms are arranged in long rows, as shown in the accompanying illus- tration, and are placed so that there are fourteen inches of clear space adjacent to the vehicles. This is sufficient to allow each car to back into or run out of its stall without disturbing the cars next it. The platforms, being inside of the car wheels, do not prevent jacks being used in the clear space between vehicles to lift the wheels off the floor for the removal of tires. A small concrete bumper, about two feet long, ally into its stall, with the platform situated longitu- dinally beneath the car,and its edges almost touching the insides of the front and rear tires. As the platform is of sufficient height to prevent the car from mounting it when backing up, each vehicle is automatically placed in its proper position, and will be pre- vented from running in any other. hirer concrete ramps take the place of elevators. twenty feet wide, permitting one line of cars to go up and another to go down at the same time without danger of collision or other mishap The ramps are six inches wide and six inches high, is provided behind each of the clear spaces between the islands at the rear, to serve as _ stops for the rear wheels of the cars. This garage, which is being built by one of the large automobile concerns in New York city, is four stories in height, with a total floor area of 205,000 square feet; of which 164,000 square feet will be given over to the ac- commo- dation garage will be the largest structure of its kind in the world. The garage will have a res- taurant and clubroom for chauffeurs and will offer every personal convenience to owners 388 The washstand con- sists of an iron age framework sup- ported on rollers running on_ steel tracks suspended ~~ from the ceiling of six hundred cars. As shown in the accompanying cross-sectional view, one of the ramps leads from the street level into the lower or basement floor, while another leads from the second to the third floor. Still another ramp, at right angles to the second, serves the fourth or top floor. The maximum grade is fifteen percent. Another original idea incorporated in the design of this garage is the method of washing thecars. This is done in the aisle toward which each two rows of cars face. A movable washstand is pro- vided, which overcomes many of the difficulties and some of the expense connected with washing the vehicles. - This washstand consists of Popular Science Monthly and lights being close.up to the frame so that they clear the top of the car. The curtains are then pulled down to protect the fronts of the cars facing the aisle, the lights are adjusted to illuminate the proper parts, and the vehicle is then washed with hose attached to convenient water taps near the structure columns. Among the special conven- iences provided are a large room where owners can make minor repairs on their cars; lockers for each car.owner; a restaurant and club-room for chauffeurs; a vacuum system with taps on each floor for cleaning car interiors and the usual gasoline, water and oil pipe- an iron framework supported on rollers running on steel tracks suspended from the ceiling and extending the en- tire length of each aisle. Canvas curtains mounted on spring rollers like ordinary window-shades are hung from the frame on the sides parallel with the length of the aisle. These protect nearby cars from the splashing. On the other two ends of the frame are hung two banks of electric lights in parabolic reflectors, which are also supported on spring rollers. In operation, the car to be washed is pushed straight out into the aisle. The washstand framework is then pulled up into position by means of a rope, the curtains Backing a car into its stall. The island platform guides the car into place lines with draw-off stations at several points on each floor. When Postage Cost Ten Dollars an Ounce AN FRANCISCO has had an interest- ing history. The first settlement dates from 1776. The United States flag was raised over the town in 1846. Two years later the city had an estimated population of twenty thousand, caused by the inrush of fortune seekers. The first regular over- land mail communication with the East was established by pony express in 1860, the charge for postage being five dollars for half an ounce. e Vin i EGER ae a Seda EEN ae _ pieces of mica set in metal rims _ mask. ‘sea serpents but which, upon Popular Science Monthly with es ULPHUROUS fumes rising from heat- ed crude oil made life miserable for the horses and men employed in a Los Angeles briquette plant. Clouds of yel- low smoke, surcharged with the fumes, hung over the yards. Its effect upon the eyes was extremely painful and injurious. To protect the horses as well as the men in carrying the steaming material to the briquetting machine, both were fitted with goggles. The drivers were equipped witha type similar to that used by motorists, while the horses wore an apparatus composed of circular ee euereing the Eyes of Horses Gogsl and held in place By, a leather “Busting the Bronchos”’ of the Sea at Palm Beach HE Old Man of the Sea and all his mermaids are wondering what the commotion in the vicinity of Palm Beach can be. Riding the surf each balmy morning appear men and women mount- ed upon what appear to be real closer examination turn out to be steeds made of wood and can- vas. Breasting the waves astride these floating creatures is soci- ety’s latest diversion. The sensation is not so thrilling as surf- _ riding on boards, as the Hawaiian does it. _ That is due in part to the fact that these practice. sea bronchos can be ridden with very little The photograph gives an idea of the amount of enjoyment the sport fi cyan Syne ty ty, affords. The man directing his mount is one of the most expert surf- riders. They ride ‘the surf at Palm Beach aow on curious tolling, pitching horses made of wood and canva> A horse wearing goggles to prevent sulphurous fumes and smoke from injuring the eyes 3898 Why There Is Nothing ‘‘Just As Good’’ as Cork HEN a man goes into a hardware store for a supply of cork for some specific purpose, he generally gets what he asks for. The reason why the dealer does not endeavor to persuade him to try some- thing else “‘just as good,”’ is because there is nothing else he could offer. Cork is cheap, and for ages it has stood alone in its field of usefulness. It is tough and elastic and its specific gravity is only 0.24. This added to the fact that it is impervious to water, accounts for its use in life-preservers. The cork oak which grows principally in Spain, Portugal, Algeria and Southern France, furnishes the supply. Only the outer bark of the tree is used for the commercial product. When the tree has attained a diameter of approximately five inches, which it usually does by the time it is twenty years old, the cork, as the first stripping ‘of bark is called, is removed. This cork is so rough, coarse and dense that it has little commercial value. But its re- moval does not kill the tree. On the contrary, itseems to promote development. The stripping is done in July and August, and great skill is necessary in order not to injure the tree. If itis in- jured at any place the growth there ceases and the spot remains ever afterward scarred and uncovered. But if the stripping is correctly done the growth of new bark begins at once and the subsequent layer is of finer quality than the one removed. Each year the inner bark—the real skin of the tree—forms two layers of cells, one within, increasing the diameter of the trunk, and the other with- out, adding thickness to the sheathing. The instruments used in the strip- ping are either the crescent-shaped saws of the Algerians or the long- handled, wedge-shaped hatchets of the Spaniards. A mark is cut clear through the bark around the base of the tree and another just below the main branches. The two parallel incisions are then connected by longitudinal slits, following the deep- est cracks in the bark, after which the bark is pried off. eS ota Bie gas A new strength-testing amusement device which settles an international question The Stars and Stripes Forever! The player first deposits a coin in the slot and turns the crank in the box at the base of the appara- tus. This unlocks the cannon from its moorings so that the player can shove ‘it up the incline the patriotic question involved in the timely exercising game devised by Hans Gafner, Escanaba, Michigan,'‘must be well prepared. His delivery must be Te player who undertakes to settle strong or his ‘‘cannon’’ will go up the incline and down again, while the Foreign flag still flies above the fort. The object of the game is to displace the Foreign flag on the fort and to raise the Stars and Stripes by the impact of the missile driven by the player. The player first de- posits a coin in the slot and turns the crank in the box at the base of the apparatus. This unlocks the cannon from its moor- ings and permits the play- er to move it into the field for action. Following this the player grasps the rail- ing firmly with one hand, and seizes the cannon with the other. Then he gives it a hard, firm push to send it up the incline, where on reaching the top of the incline it registers spectacularly. The Foreign flag. is supplanted by Old Glory, and the doors of the fort swing outward, displaying a gay and patriotic picture. The result is ob- tained by means of a spring-pressed rack within the fort or tower, with which the cannon makes impact, and by means of which the flagstaff bearing the United States flag is rotated into display posi- tion and the Foreign flag rotated out of view. Bevel gears connect the flag staff / ROTATING FLAG STAFF WITH DOUBLE FLAG Detail of the end of the incline and the interior of the cabinet with a rod that is rotated by another gear that meshes with the toothed portion of the spring-pressed rack. The friction of the prominent cable retards the cannon as, ~ it rolls down the incline, so that its return is not a rapid one. When it finally rolls back to its starting point it hits a lever that again locks the cannon and causes the doors of the fort to close and the flags to return again to their original position. The operation of the device is unique, but the principle involved is the same as that of the ‘‘test- your-strength”’ apparatus familiar to frequenters of Coney Island and similar pleasure resorts. In the older device a hammer is used to strike a great ball, which rings a bell at the top of the column. Zinc Wire Is Now Used at the German Front N order to save as much as possible of her copper and iron, Germany has developed DOORS THAT OPEN ———, FOLLOWING SHOT 57 EXHIBITING PATRIOTIC 7 PICTURE 3 the zinc wire. She is now using it for both 4 ordinary electric wiring at home and for .— telephone work at the front. Considerable trouble was experienced, however, in per- fecting the various stages of manufacture. The process of drawing the wire was especially difficult. But after innumerable experiments success was attained. The new wire has been found to have double the conductivity of iron wire. folavey q : Popular Science Monthly 391 Determining the height of a spire by multiplying the reading of the instrument by one-half of the length of the spire’s base Doing Your Tire Repairing at Home z with an Electric Vulcanizer N electric vulcanizing outfit which 4 _enables the automobile owner tomake ' his own casing and inner-tube repairs in / _ twenty minutes or less, has been placed on _ the market by a western manufacturer. It ' consists of a vulcanizer with a curved _ surface for casing and a flat surface for inner tube repairs. Repair materials pro- _ vided consist of Para rubber, cement, wax _ paper and emery cloth. The vulcanizer _ works on a one hundred and _ ten-volt _ electric circuit. In repairing a cut in the casing, gasoline _ and the emery cloth are used to clean the damaged part. With the cut spread open, _ two heavy coats of cement are applied and _ are allowed to dry. - After this the hole is - filled level with small pieces of rubber gum _ and the repair covered with wax paper. _ Then the vulcanizer is ready to be attached. _ This is done by applying the curved portion _ against the repair and fastening it securely q - we casing by placing a chain around the Sane _ felloe of the wheel and drawing up the ; : Seaethioie aes Measuring Sloping Roofs Without After connecting the vulcanizer to the _Breaking Your Neck current supply, the button is pressed and ee instrument shown in the illustra- tion above is designed to enable a _ electric circuit being opened when sufficient Workman to determine the vertical and sloping height of a spire quickly and > ‘without risk. It is placed against the sloping sides of a roof, the pivoted pointer is made level, and a basic number by which to calculate the height of the —_ a : 2 + p es uc ; the repair proceeds automatically, the heat has been generated to prop- ~ erly vulcanize the rubber. For : extra deep or large cuts the : button is pressed a second 3 ‘time after the vulcanizer has cooled off. = In oval: Vulcanizing roof is immediately ob- = ae casing with the tained. For example, the Fy oy Eig tedheag number given by the in- E Ree ten tube with strument when fitted against the side of the triangle shown in the photo- graph is twenty. By. multi- plying the number of feet in the base of the triangle by twenty we will immediately obtain the vertical height, or the altitude, of the triangle in inches. The angle at which the side slopes is also given, and for the triangle in the photograph, this is roughly sixty degrees. Hence it is necessary only to measure the base of a church spire and use this instrument to obtain its height.. The sloping height may then be figured from the simple well-known formula for right triangles. the flat side to the tire Popular Science Monthly ¥ y 4 a 5 | } \. | | The town house in which the twenty-five prize dogs find their canine heaven is lavishly furnished. Their meals are served by Japanese waiters, and they sleep in dainty steel cribs luxuriously padded These-Ganine Aristocrats Have Town and Country Mansions OZENS of socialists are born every time the newspapers print an account of some prodigal millionaire who gives diamond jewelry as favors at a banquet. But the sumptuous mansion for lap-dogs, two rooms of which are shown in the photographs. above, will create more bomb-loving socialists than the most ambitious of banquets was ever responsible for. New York has another thing to be ashamed of. If every man who is conducting a personal ‘‘hunger strike,’ walking job- less about America’s streets, possessed a good position and plenty of food, one might con- template the ‘‘finest dog house in the world” witha degree of good-natured forbearance. Twenty-five prize dogs, with plenty of choice food and warm beds, have an ideal existence at their ‘‘town house,’ in the heart of New York city. To make matters even more unbearable to the socialist, a summer house is provided for them in the country. The ‘‘town house’”’ is lavishly furnished with Japanese furniture and ornaments. Each dog has a valet or maid. Scented baths in individual basins of finest crockery are provided for the twenty-five little aristocrats An Ant Can Carry Ten Times Its Own Weight; But Suppose It Were Bigger s O to the ant, thou sluggard,” and watch it carry a weight fully ten times its own, for a distance equivalent to miles considering its size, and then blush for shame because man cannot do at least as much. Let the horse blush, too, for even it can carry loads only about equal to its bodily weight.. ; But is the ant really so superior in strength? Would it be able to perform itsremarkable carrying stunt if it were as heavy as a man ora horse? Science says not, and explains that since an ant’s strength is in proportion to its cross-section, not to its length, if itshould grow to twice its original size retaining its natural geo- metrical structure, it would be only four times as strong, although it would be eight times as heavy. Thus its strength would be relatively halved rather than doubled. Following the same line of reasoning, if the same ant should grow to be the size of a man, it would be able to carry only one one-hundredth of its weight, which is less than a human baby can do. Therefore, exit the ant as a perpetual reproach to man’s puniness. Te _ ee ee ee ee ee eee ee ee gS ee ay la ee ee ee Popular Science A Folding Walking-Stick with an Electric Flashlight _—_— HE walking-stick is a favorite object : of experiment with the inventors — _or it seems-sei. Efforts are constantly being made to'lift it into the ranks of the really useful.. The one equipped with the little electric lamp is no longer a cane oddity. It made its debut fully three years ago. But the same cane in the new folding shape is certainly the first-of its kind to come our way. The light switches _ on and off just as the light in the old cane did. You simply twist the metal covering over the light socket and the bulb comes to life. - But the new cane has. a decided advantage over its predecessor.. You can _ pack it in your trunk and traveling bag and take it along wherever you go. The two parts of the cane are connected by a steel rod with two pivoted elbows: Thus the cane can be taken apart and the upper and lower sections placed parallel with each other. The lamp is located at the most con- venient part of the stick—just a hand’s length from the curved handle of the cane. Here it is not in any danger of being turned on accidentally as it would be if it were further up or down, and it is in just the proper position to throw light on the key- hole or on other near or distant objects. The folding cane which is equipped with an electric flashlight in a most convenient location Monthly a. - Cm. a . ae < ~ ane > < t xe “3 - ¥, > Thirty-nine lengths of pipe were coupled together to make a compressed air con- tainer of about fifty cubic feet capacity Improvising a Compressed Air Tank from Pipes T is particularly difficult with the present shortage of freight cars to obtain equip- ment of any kind. Long delays are the rule before even standard apparatus can be delivered. But sometimes, in a pinch of this kind, mechanical ingenuity comes to the front and solves the problem without delay. For instance, a contractor needed a compressed air-storage reservoir quickly. An eight-inch well, two hundred and twenty feet deep had been cased all the way down and screened. Quicksand then entered. To remove it, compressed air had to be employed. No suitable air-tank was available, and no manufacturer would promise delivery for weeks. So the con- tractor hooked up lengths of ordinary pipe, as shown in the illustration. Thirty-nine lengths of pipe were used, each six feet long and six inches in diameter. Their combined storage capacity amounted to about fifty cubic feet. The makeshift served its purpose admirably. There was very little delay and the pipe was usable for other purposes when it was no longer needed to supply compressed air. Removing the skins from the stretching boards where they have been for two weeks HREE youngsters are making enough- by trapping muskrats in the Hacken- sack marshes of Jersey to equip themselves with bicycles, baseballs, bats, gloves, and all the other things thata boy yearns for. They are Charles Curtis, aged II, Harold Freet, aged 15, and George Halk, aged 16. All are of Hack- ensack, N. J., and all attend school. Harold Freet is the chief trapper, and the one from whom the other two obtained their instructions. During Freet’s spare time he hob-nobbed with the bridge-tender Bridge, over the Hackensack River. This bridge-tender was a trapper himself and knew the habits of muskrats, the laws gov- erning their trapping, and the market value of the pelts. He imparted all his informa- tion to Freet, and Freet in turn told his two pals. When the season opened, the three of them went at it with a will. Muskrats cannot be shot under the New Jersey law; nor can they be hunted at night with searchlights. They must be Hackensack Meadows. The trap catches the rat by the leg. _ ‘Trapping Muskrats A new industry for the ambitious boy : By Charles Curtis caught in traps, and in no other way. The youngsters therefore purchased about four- teen ‘‘jump traps’ and set them out in the These traps cost about twenty cents each, and are the best for the purpose. When the rat springs a jump trap, he is caught firmly by the leg. The traps are always set and emptied when the tide is out; for that is the only time they may be reached. And whether the tide is out early in the morning, or late at night, the boys have to be there. If the tide is out early in the morning, young Curtis and Halk each ties a string to his big toe when retiring the night before and drops the string out of the window. Freet delivers papers.in the morning, and is therefore, always the first ui ~ to be up. When he has delivered his pa- pers he goes to the houses of his co-work- ers and pulls away on the string. Ina very few ‘minutes his ° companions are with him.. The traps are generally set near the muskrat lodges. The lodges are capaci- ous dwelling places for the muskrats, built of grass, leaves, and rushes, about three or four feet.in height and they are always situated so that they will be above tide water. The traps are placed in the runs that lead in and out of the entrances. The law governing such trapping, however, states that the traps must not be set closer than two feet to the entrance. This gives the rat a chance for his life. If this law is violated by a trapper, he may be fined twenty dollars. When the traps are cleared, the muskrat If the rising tide does not drown it the boys kill it humanely on the Court Street 204 Popular Science Monthly The picture at the left shows the boys skinning a muskrat. The skin must be removed whole, without cutting. At the right the boys are stretching and tacking two new skins to the boards is generally alive. Often, though, the rising tide has drowned him. But if he is alive, he is speedily dispatched by a blow on the head from a stick in the hands of one of the young trappers. This blow must be delivered in a certain spot, so as to kill the rat quickly, and without soiling or in any Way injuring the fur. When the day’s bag has been collected, it is brought home and skinned. Skinning a muskrat requires skill. When the rats have been skinned, the pelts are drawn (inside out) over a pointed board or stretcher. They are then stored in a barn or other place that is dry and well-ventil- ated by a current of air. At the end of two weeks the skins are sufficiently dried. They are then laid aside. When a sufficient number of pelts have been collected, Freet brings them over to the fur market on West 13th Street, New York city, where he receives forty-five cents each for them. The season opens on November Ist, and closes on April 1st. As the season gets older, the skins become more valuable, until, toward the end of the season, they are worth seventy-five cents each. Just prior to the Christmas holidays, these boys had collected and sold forty- eight pelts. With the money resulting from the sale of these pelts, they treated them- selves to a few things they needed and bought Christmas presents. Then they returned to Hackensack to renew the cam- paign and to collect more skins, for which they will purchase what they want for the summer. The Latest Kind of Artificial Feet Are Made of Paper Pulp N spite of the fact that there is little fiction in the stories of the soaring price of paper, the uses to which this product is being put are constantly increasing in number. We have paper furniture, paper cloth, paper silks and clothes, and even paper legs. Now Dr. Svindt, of Denmark, who is responsible for the artificial leg of papier maché, has brought forward a paper foot, intended to meet the needs of the crippled soldiers. These feet are said to be strong enough to withstand ordinary usage, and they have the added advantage of being cheap. A model of the foot is made of Wire gauze, and upon this is poured a specially prepared pulp which entirely fills the interstices of the wire gauze. 396 Popular Science Monthly Stripped of His Clothes by a Projecting eave! HE collection of clo- thing shown in the picture is interesting only as an illustration of how close a careless work- man can come toa serious accident and yet get off practically unscathed. The man in question was cutting an elongated hole in a die block with a cut- ter projecting about three-sixteenths of an inch. While the drill press was in motion, the elbow of the workman, who was leaning on his work, came in contact with the cutter. The cutter caught his sweater and stripped him of practically his entire clothing, consisting of sweater coat, street coat, overalls, vest, shirt and undershirt. The beneficent Provi- dence that watches over even the criminally care- less saw to it that he Clothes torn from a workman by a projecting cutter on a drill press. Hewas only slightly hurt escaped with only a dis- located shoulder. Saving Coal by Feeding a Fire with Hot Air UR fuel bills are high because we get so little heat from the coal we burn. If we could take out of a piece of coal all the heat that Nature has stored up in it for us, our coal bills wouldn’t bother us. As it is, we waste most of the coal we burn. Half the heat goes up the chimney and most of the gases arising from a hot bed of coals will not burn because the fire isn’t hot enough to make them combustible. To eliminate this unnecessary waste Charles W. Huse, of Gary, Indiana, has invented an air-feed, or auxiliary draft, The air-feed, or auxiliary draft, which introduces heated air which introduces heated air into the firebox, thus giving a perfect mixture of all the gases and forcing the flames to all parts of the firebox. The air is ad- mitted through an _air- intake equipped with handles and a regulating shutter. It is taken to the firebox through a> tube. A nozzle on the inner end of the tube distributes the heated air over the flames. When the furnace is being fired the door as well as the tube is swung around to one side out of - the way; or the tube can be raised, lowered, or turned in any directon. Thus, in banking a fire for the night, the nozzle of the tube is turned up- ward by means of the handle, allowing the heat- ed air to pass through the flues of the boiler or furnace. The nozzle is made of a specially prepared metal which will stand excessive heat even when the air is not passing through it. The heat supplied by the furnace after the in- stallation of the device is greatly in ex- cess of the amount given out be- fore, even though only one-half the usual quantity of coal be used. The saving, there- fore, is obvious. The tube as well as the door may be swung around out of the way, or it may be raised, lowered, or turned in any desired direction The Cavalry Horse of the Air At last the secret of German fighting aeroplanes is revealed By Carl Dienstbach Ythistimeevery- T Pimee a ee ; one has heard of for deeming che cate SPRING HOLDING TRIGGER: the famous Fok- FORWARD op, ker aeroplanes— the fighting chariot of the air in which the fa- | mous German avi- ators Immelman and Boelke performed so : many daring exploits! Very little has been _ published by the Ger- _- mans about the Fok- \\_ 87 Sa a2 LEVER OPERATING BOWDEN NBM WIRE Wert 15 PRESSE ker beyond the fact that it is — and strong, and that it . Nee ? can Disot up like a oe 7-5 ae balloon, plunge like a ee —_ os stone, rise again, tum- ble about, and fight like a cavalry horse, all because of its ex- cessive power and its extreme lightness. | Much more is now known of the Fokker. type the propeller is mounted in front, the Interesting as its construction is, still more technical difficulty of firing the gun through interesting is its single machine gun and the _ the blades of the swiftly revolving propeller manner in which it is fired. August Euler had to be overcome. An aeroplane motor patented the idea of aiming a gun not by explodes thousands of charges of mixed air swinging the weapon itself, but by manipu- and gas in a minute; a machine gun fires lating the air craft on which it was mounted. about six hundred shots a minute. If it is That was the underlying idea carried out in possible to time thousands of motor ex- the machine-gun mounting of the Fokker. _plosions with mathematical nicety, surely it Euler exhibited his device in I912 at the is not an impossibility to time rapid but Berlin Aeroplane Exposition. PrinceHenry less frequent machine gun discharges with of Prussia no sooner saw it there than he equal ease. The propeller blades intercept ordered it to be withdrawn at once and _ the gun only during the one-fortieth part guarded as a military secret. of the time required for a complete revolu- Military experts have always wondered tion. The solution was simple: Let the what is the best way of making an attackin motor operate the machine gun and fire the air. Ramming is obviously impossible. it at the proper time. And so that was Bomb dropping is uncertain at high speed done. even at close range. [Euler’s invention The operation of the gun by the marks- solved the problem for the Germans. man is not in the least interfered with. The Mount a machine gun on an aeroplane so - pulling of the trigger indicates merely when that the entire craft must be turned in firing should begin and end. It must not order to aim the gun andakindoframming be forgotten that the propeller of the principle is at once applied without en- machine is directly coupled to the motor, i dangering either the machine or the ram- as our illustration shows, and that it makes 3 mer. The firing ranges, to be sure, are more revolutions a minute than the most short—at most a hundred yards. rapid automatic gun would make firing Since in racing monoplanes of the Fokker _ shots in the same length of time. 397 KEY WHICH LOCKS FORE AND AFT) MOVEMENTS USED IN ELEVATING? A cut-away drawing showing the construction of the Fokker aeroplane with its machine gun which is aimed by swinging the entire craft Can You Name These Cars? Here’s a Chance to Win $50 in Cash Study the photographs on pages 398 and 399. They-represent parts of well- known cars. But what cars? You may recognize a.car.as it-whizzes past, just from its general appearance. But do you know the finer points of standard auto- mobiles? Do you know the mechanical advantages of the construction shown ? To win the $50, you must observe the following rules: 1. Use the numbers on the photographs in your answers, for identification. 2. Point out the identifying feature of each photograph on pages 398-399. State the advantages of that par- ticular feature—whether it is com- mendable for mere looks, for the sav- ing of material, for mechanical reasons, etc. This is not a guessing contest but a test of. intelligence. 3: 7° POPULAR SCIENCE MONTHLY Write your answers on separate sheets of paper, each bearing your name and address. Don’t make your answers part of a letter. Give the reasons for each answer in a little article. Allow no more than one hundred words for each article. The prize will be awarded to the competitor who submits the best set of articles displaying the most auto- mobile intelligence in his answers. The contest closes on March 15, 1917. The correct answer and name of the winner will be published in the ‘May issue of the PopULAR SCIENCE - MONTHLY. Address answers to the AUTOMOBILE CONTEST EDITOR 239 Fourth Avenue New York 2QR Tee SOE eee Sey ee a eT $50 Prize Contest. See Opposite Page STS ety 399 400 The Latest for Hair Dressers Is a Combined Chair and Basin HE discomfort and inconvenience of getting the hair shampooed is almost entirely eliminated by the use of a special chair and basin. The chair, placed about six inches in front of the basin, has a hinged back which is lowered until the head rests comfortably on a rubber neck-piece forming part of the basin. With the head in posi- tion the hair can be washed thoroughly. Soap lotion is applied through a small faucet and hose at the left. A gas heater in a water compartment makes it possible to get hot water instantly at any desired temperature. Sterilizing a Thousand Quarts of Water with a Vest-Pocket Apparatus OME remarkable claims are made for the efficiency of a vest-pocket water sterilizer that should free all travelers, campers and soldiers from the germs lurking in contaminated water. The apparatus is distinctly portable. A complete equipment of large size is capable of sterilizing eight thousand quarts of water. It weighs only a few ounces. Ordinarily, however, the apparatus is used to purify a small quantity of water at a time, a cupful, for instance; but it may be used again and again with but slight re- adjustments. The principle of the invention is simpli- city itself. Two electrodes are brought into A chair which has been designed to make shampooing operations easy for the shampooer and the shampooee Popular Science Monthly electrical contact with a battery comprising a num- ber of dry cells, such as are used in pocket flash- lights. Between the two electrodes is some blot- ting paper which has been charged with com- mon table salt. Thus ¥ ina glass or bucket of / water, the sodium chlor- ide, or table salt, is elec- trolytically changed into so- dium hypochlorite, which con- stitutes one of the most powerful oxidizing or sterilizing agent known. = The effect of the oxidizing agent is to destroy the dangerous germs or bacteria and to render the water sterile and safe for drinking. The water does not lose any of its dissolved gases and is not flat or otherwise unpalatable after it has been sterilized. Furthermore, the salt used as an electrolyte does not impart to the water a salty taste, since very little of it is used. Within a short time after bubbles of.gas evolved at the electrodes rise to the surface, all parts of the water have been subjected to the purifying oxidation. Moving the electrodes BATTER about in the water ac- celerates the action. Charles F. Burgess, of Madison, Wisconsin, is the inventor. ag 4 PUSH BUTTON>( CONTACT SOCKET STERILIZING ELECTRODES a Sterilizing a cupful of drinking water with the vest-pocket apparatus. It only takes a minute in placing the electrode PO any a ee ‘ we bees ik ee SMUT SATA AO THN ee a eae FE SRV GT LAE PR = TR ee SSL RSE OE TPE AS DSEE ERA _ Treating Maniacs with Water & How the modern physician soothes raving luna- tics with nothing but hot and cold water By John E. Lind, M.D. Senior Assistant Physician, Gov't. Hospital for Insane, Washington, D. C. with constantly in the press and in our daily speech, but it is doubtful if many people know just what it means. Probably the most common picture con- jured up by the term is a vision of a wild- eyed lunatic dashing madly through a terrified crowd, shooting and stabbing, until he is overpowered by the police and borne away to a padded cell where his shrieks are heard but faintly through the r i NHE expression ‘‘raving maniac’’ is met walls. While a maniac may run amuck in - the streets before he is apprehended, this is not so common nowadays. Our knowl- edge of the real nature of insanity is becom- ing more exact, and we are able to detect its presence sooner as well as to treat it more intelligently and humanely. A little over a century ago the person who was mentally ill was regarded as something between a wild beast and a criminal. He was chained hand and foot to a stone wall in a dark, ill-ventilated cell; his food was doled out to him at the end of ~ a long stick; he was exhibited in iron cages to passersby, who, by paying a few pennies, were at liberty to ridicule him or “‘stir him up” in any way they chose. When his keepers thought it advisable he was beaten, ducked under the water or otherwise ill- treated with the idea that the evil spirit, which was supposed to have taken posses- sion of him, could thus be driven out. Towards the end of the 18th century, Pinel, a French doctor, made the experi- ment of striking the chains from the in- mates of Saltpetrie, a famous old asylum at Paris. His example was soon followed throughout the civilized world. Even after this great step forward, however, many strange and, as we now see, cruel methods of treating the mentally ill were practised, tuch as strapping them in rotary swings which revolved a hundred times a minute, bleeding them freely, etc. In all the history of the treatment of mental disorder it is the maniac who has given the most trouble, and naturally so. He is quiet neither night nor day. Pacing The continuous bath for raving maniacs. In this the patient lives, eats and sleeps restlessly back and forth, tearing his clothes to pieces, singing and shouting, refusing to eat or sleep, he has always been a menace to life and property. In thousands of cases he has so worn himself out that, his vitality reduced to a low level, he has been the prey of some disease. What the Strait-Jacket Means There have been three main ways of treating maniacs, all of which have had for their basic idea the object of restraining them. The first of these ways was by actual restraint; that is, the excited person was put in a strait-jacket or bound hand and foot. What torture this was to the poor sufferer will never be known, except by those who have endured it. Some of the readers of the POPULAR SCIENCE MONTHLY have had what are termed the “‘fidgets,”’ when it seems impossible to be quiet for more than a second. If you can imagine having the fidgets a hundred times as badly as you have ever had them and if you can imagine being strapped in a canvas jacket with your ‘arms bound tightly to your sides so that you cannot move them and being kept in this way for days at a time you will have a faint idea of what the maniac suffered during the years when this was the only method of handling such cases. Following these mechanical devices for restraining them, patients were given power- AVI Administering a needle bath massage. are soothing to the nerves and at the same time invigorating to the body - ful narcotics, ‘‘knock-out-drops”’ in reality, until they sank in a stupor. When the sufferers revived a little from the depressing effects of these powerful chemicals and began to show signs of life they were again drugged. This was kept up for weeks at atime. In such a state they were of course no trouble to those who had charge of them. In the course of time they recovered; for nearly all maniacs do recover. The exponents of this method of treatment claimed to have founda cure ay for mania. It was found Kay that the abuse of the system ‘ by these powerful drugs had evil results. Some of the patients passed from stu- por into death, and those who recovered mentally often found their digestion ruined and their general health impaired. The Modern Hu: mane Water Cure So, the age of chemical restraint passed away and nowadays we have found a treatment so simple that it is no wonder that it was over- looked before.. It is nothing more nor less than water. Hot water, cold water, shower baths, tub baths and sitz-baths, and every conceivable manner of applying water The effects of this. treatment a cold wet wrap around the waistline, is a cure for sleeplessness ‘‘Neptune’s girdle,” Popular Science Monthly medically is to be hospital for the in- sane. Besides being used for the excited cases, it is also found to have a good effect on all cases, benefit- ing physically even if it has little or no effect on the mental condition. Water is also found to be a valuable curative agent for great numbers of people who suffer, as the nerves, their trouble taking the form of hysteria or neuras- thenia (nervousness) in the more severe cases and sleepless- ness and periodical ‘‘sick headaches” in the milder ones. There are three main ways of giving the water treatment—by the pack, by the “Scotch douche” and by the continuous bath. By “packing” a patient is simply meant wrapping him tightly in sheets wrung out of water of the desired temper- ature, pinning blankets tightly around him and leaving him in the sheets for anywhere from a half hour to two hours. Packs may be either hot or cold. The temperature for hot packs is about 105 degrees, for cold packs about 60 degrees. In either case an ice-bag is put to the head and a hot water bottle to the feet. It is astonishing to see the soothing effect on excited patients. Mildly excited patients, who, with- out this treatment, would eat or a but little, tear their clothes _....+ to pieces, use pro- fane language, and in -general cause much trouble, are kept quiet and tractable with water, and after they have been packed in at bed- time, are able to sleep soundly. A hot pack for an hour at night would cure many cases of sleeplessness in normal life, by the way. The Scotch douche may be described as a shower bath raised to the nth degree of perfection. It consists of four upright found in the modern saying is, from their 4 3 = ea Ne ey ee ae ye ae _— NOR a ee ee _ teen feet away, Popular Science Monthly pipes forming a square; these curve over and meet at the top to form an ordinary shower. The pipes at the corner are perfor- ated so that the patient gets the water from the sides and top at once. The Scotch douche is regu- 403 the patient’s body, making it a spray against the more sensitive parts and a hard stream upon the less sensitive ones. Chiefly attention is directed to the spinal column and the cold stream is run up and down the back-bone sev- lated by an operator at a table about fif- by means of levers. A ther- mometer near him indicates the exact tem- perature of the water the pa- tientis getting. When the pa- tient steps in the bath, for instance, the water is made about 106 de- grees, it is kept at this for about ten sec- onds, then the temperature is gradually re- duced until it reaches 60 de- grees or even lower, if the patient is able to stand cold water, the test being whether he gets a warm, healthy reac- tion afterwards. It is kept at this low tem- perature about ten seconds and then turned off." Then follows the unique feature of the Scotch douche. The operator controls at his table a short hose with a nozzle and through this he plays a stream of cold water up and down » SL caer The Scotch douche is a special kind of shower bath. The temperature of the water is gradually reduced un- til the patient can stand a cold stream along the spine ‘eral times. The patient then steps out of the bath and is given a brisk rub- down. Curing Raving Maniacs in Bath-Tubs The con- tinuous bath is just what its name implies and is chiefly used for very excited pa- tients, the “raving mani- acs’ referred to before. An ordinary bath- tub is fitted with a mixing chamberabove so that the water is kept at an even temperature, this being body temperature or a degree higher. Many of these are equipped with a safety-valve so that if any accident happens the supply is automatically shut off. Thus, if the valve is set at 105 degrees and the cold water stops running for some reason, the tempera- ture of the water in the bath rises rapidly, but at 105 degrees the water is shut off. Of course patients in a continuous bath are always attended by a nurse who is supposed to watch Pt pn nf mm tg en A patient in a “pack.” has been wrung. These are wrapped tightly about the body and over them blankets are pinned This consists of sheets out of which water of the desired temperature Patients taking a hot-air bath before being given a Scotch douche. the temperature constantly. Butall human beings are fallible, and, if the nurse should happen not to be watching the thermometer during those few minutes when the water began to get hot, the patient might be scalded; hence the safety-valve. In some hospitals a sheet is stretched across the tub over the patient, only his head projecting. In others there is nothing over the patient, in which case he can escape from the tub. He does that fre- quently at first; but since he has no clothes he finds the temperature of the room chilly and is glad to get into the water again. His meals are served to him in the tub. He sleeps there. He -may remain in the tub for weeks at a time. The continuous bath has also been used with great success in treating severe burns. Often before being given a Scotch douche treatment a patient is put in a hot-air bath. He sits on a stool in a little cabinet, with his head projecting through the top and a cold cloth bound aroundit. The interior of the cabinet is heated by electricity to 130 or 140 degrees. Soon the patient begins to per- spire profusely. Then he goes under the shower bath. The same result may be obtained by a hot pack for BODY PLATE “oe TOFIT BETWEEN game LINING AND LEATHER The fastener consists of a tongue and body member. attached by means of punch holes and eyes Popular Science Monthly half an hour before the douche. Curing Sleeplessness A simple treatment for sleeplessness often effectual involves the use of ‘‘Neptune’s girdle.”’ Anold sheetiscutin half. One half is folded until it is about three inches wide. Just before bed- time thisissoakedin cold water, wrung out and wrapped around the body at the waist line, next to the skin. The other half of the sheet is folded until it is about five or six inches wide. It is kept dry, and wrap- ped over the first sheet. Another simple way in which water may be used medicinally is in headache. We all know what a relief a cold compress gives to a throbbing head. Sometimes a hot footbath will relieve the pain. If not, try the application of hot and cold water alternately to the back of theneck. The description of the ways in which water is used in mental disorder must not of course be taken to mean that we have discovered a cure for insanity. We have merely found that it is easier for us and more pleasant for the excited patient to subject him to the soothing influences of the warm bath than to beat him with clubs or drug him with powerful narcotics. Use This and Your Shoe-Laces Will Never Come Untied ANY a disposition has been sorely strained because a simple little thing like a shoe- lace wouldn’t behave. A Sacramento, California, man—Alexander F. Urgu- hart—hasinvented a shoe- lace fastener which prom- ises to keep the laces for- ever in the background. The fastener is nothing more than a single piece of stamped metal attached to the shoe half an inch from the strap at the back of the shoe. The laces are drawn up under this and held securely until removed. The interior of the cabinet is heated by electricity to induce free perspiration SHOE LEATHER oe ae ee Cee SS ee SS eS ’ Ss oe ee tions. Popular Science Monthly Loading Platforms That May Be Moved from Place to Place ANY large factories and other plants are confronted by the problem of moving quickly thousands of boxes, barrels, sacks and packages from storage to wharf and from wharf to shipboard or railroad car. Using hand trucks, it would take a force of 405 containers. The loader is designed for use in putting barrels into freight cars and onto high platforms. It is constructed on an iron frame and is provided with wheels so that it, too, is portable. All of these machines are equipped with electric motors to furnish the power. They are so light in weight that they are easily thirty men to handle one thousand, five hundred box- es an hour. Several types of portable machines have been put on the mar- ket to relieve this situation. One of them is a moving platform on wheels. Han- dled bya force of half a doz- en men, it can do the work of thirty, eliminating confusion and avoid- ing the delay of unloading hand trucks. One of these conveyors is one hundred and forty feet long and is made up of seven sec- It can move one thousand, five hun- dred boxes of eighty pounds each every hour. For the benefit of warehouses and manu- facturers who find it necessary to stack large quantities of bags and boxes, a stacking machine has just been put out. It is an in- clined moving platform supported on an iron frame equipped with rollers, making the apparatus ‘‘portable.’’ It is physically impossible A for men to stack heavy bags very high up. The new machine, however, is de- signed for heavy work. It can handle three hundred and forty-pound sacks and stack them up as high as fourteen feet and six inches. It is also used for “‘breaking down”’ piles when necessary. The quick loading of barrels has* also been solved by machinery. A barrel load r, whichcan handle five hundred-pound barr 's at the rate of one hundred and eigk * an hour is coming into use in plants wheic barrels are the principal shipping A barrel loader for placing barrels on freight cars or onto high platforms. The apparatus can easily be rolled from place to place as shown on the right The cord prevents any kickback transported from one place to another by oné man. The amount of current necessary to run them and the cost of operation are comparatively small. A Simple Device for Taking the ‘‘Kick”’ Out of a Revolver HE ability to shoot straight with a revolver is a gift possessed by very few. It is easy enough to sight accurately along the barrel, but the “‘kick”’ of the re- volver causes the barrel to swerve. ~* To obviate this, John E. Webster, of ~ Washington, D. C., has invented a muzzle controller which prevents the revolver from jumping up- ward when the trigger is pulled. To the under side of the barrel at the end is welded a flange, similar in appear- ance and size to the sight above it. Attached to this is a flexible cord. At the other end of the cord is a metal ring large enough in diameter to slip readily over the little finger on the firing hand. The length of the cord is regulated to suit the person firing the revolver, the idea being that when the weapon is raised to shoot, the cord is ‘held taut and consequently it is impossible for the revolver to swerve. 406 Popular Science Monthly A Golf Ball’s Wash- ing Machine HE unfortunate golf ball often be- comes covered deep with mud, and dras- tic measures are needed to get itclean. That explains why the ma- chine pictured has been | invented. The appliance is like a scrubbing machine. It consists of a The patient is lowered upon the table or bed, the center strap is withdrawn, and the two halves of the stretcher separate A Reversible Stretcher with Two Dovetailing Sections HE trouble with mest stretchers is that the] patient has to be moved from the stretcher instead of the stretcher being removed from the patient. The accom- panying illustration shows a new stretcher which parts in the middle, permitting the patient to be lowered upon the operating table without disturbing him. The two halves of the web are merely drawn away from under him. The two parts of the stretcher are toothed, and dovetail into each other. A strap, which passes through the indenta- tions, holds the web securely together until it is withdrawn. The stretcher can also be reversed and carried upside down when used in close quarters. This one feature enables it to be used with seven inches less headroom than other stretchers. Sacrificing Diamonds for Accuracy in Manufacturing Automobiles NOUGH diamonds are sacrificed each year in the average auto- mobile factory to fit up a dozen kings’ - crowns! Quantity production of auto- mobiles requires that every one of the thousands of parts turned out by ma- chinery must measure up to a high standard. Only then will the parts of the assembled automobile work togeth- er smoothly. The emery wheels, used for rapid finishing, must be “‘ trued up” withcorrespondingaccuracy. Nothing less hard than. the diamond can be depended upon for this “‘truing.”’ set of rotary bristle-brushes placed close together so that they enclose the golf ball when it is placed between | them. The golf ball is pushed down between the brushes into a cup-shaped holder near the bottom of the machine. The bristles are then rotated downwardly by the turning of a handle which connects _ with the brushes by bevel gearing, as shown in the accompanying illustration. The stiff bristles pass through water placed in the bottom of the machine, and when they pass over the golf ball they scrub off the mud and carry it down into the water. Moreover, the ball keeps constantly turning and new surfaces are exposed to the. brushes, so that the entire surface quickly becomes clean. 4 The turning may be explained by the fact that the grip of each of the brushes on the ball varies in strength. The brushes that — grip harder are able to turn the ball around with them. By turning the handle back half a turn, the scrubbed ball is lifted up so that it may be taken out of the machine. The machine takes up a space of only nine by five inches. — The washing machine may be attached to any convenient sur- face, as at left. Below is a view of the interior mechanism BOLTS FOR - MAKING ATTACHME WATER OUTLET TO TEE STAND OR TO SAND BOX Ce ey ee ee a a ce ee) eT — a as oe wr The Greatest Game in the World How the fleet at battle practice hits the target at seven miles By Captain Frank E. Evans United States Marine Corps Firing a broadside or “salvo.” The huge bulk of the shipslidestoport . like a crab from the force of the mighty blast. The shells con- tain sand instead of the regular explosive © Underwood and Underwood, N. ¥. HEWN: the American fleet — steams out to sea for its battle practice every man on _ board, from the youngest ap- prentice seaman to the grizzled => 2 Admiral, knows that he is about to 6° play the greatest game in the world. Back of it lies a wealth of tradition. No other game can approach it in science, in the millions invested, or in thrills. It is played with the gray steel tubes of twelve-and fourteen-inch guns that serve up thousand-pound projectiles. The game is the culmination of months of patient practice. The reward is the privi- lege of painting a three-foot white E, mean- ing ‘‘Excellent,”’ on the winning turrets and, for the champion of the fleet, a red pennant with a black ball in its center to be flown at masthead for a year. When the fleet steams out past the Capes of the Chesapeake to its favorite playing ground, rails and stanchions are unshipped, ladders housed and _ life-lines rigged along the bare decks. Cabin doors C) Int. oe. Serv. Above: The range-indicator on the Wyom- ing. The chang- ing figures of the range flash up like those in a cash-register are stowed away and pic- tures andelec- tric light Se bulbs laid flat raon in bunks to —_ save them from the guns. Boats are swung inboard and ‘‘nested,’”’ the smaller ones in the larger ones. If you walk about the decks, you will see vegetable lockers, boats, crates and all wooden gear tagged “‘overboard.”’ And over they would go in a real battle. The quick tattoo of battle gongs clang noisily, insistently, when the teams line up for the final practice, calling them to “general quarters.’ From the wardroom the ‘spotters’ come storming up the ladders. Glasses to watch the splash of the shells are strapped over their shoulders and chin-straps hold on their visored caps. Some are in dungarees. The members of the gun crews drive past you at the double quick to their stations; bluejackets inside the turrets, bandsmen to the sick bay, the 407 The Great Twelves and Fourteens Lunge At top: The greatest game in the world is played with gray steel tubes of twelve and four- teen-inch guns that serve up thousand-pound pro- jectiles. These travel at one half mile a second and throw up cascades of white water that can be seen nearly ten miles away in oval above: The shell splashes into the water just short of the target and tosses a whirling col- umn of white spray into the air. You can easily fol- low it (picture on right) as it tumbles along, striking the water again and again, and skimming across the sea in great bounds and Roar as Though the Battle Were Real : Above: Behind her each battleship of the defending division tows a target at eight knots. The target is a scant four hundred yards astern— uncomfortably close when the big fourteen-inch guns are trained on it. Two targets are towed by this ship In center above: Al- though the big shells are striking just four hundred yards astern, the errors in the range are either “‘shorts”’ or “fovers.’’ Lateral errors are rare. The photograph shows a sailor signaling to the range-finder a shot “short”? of the target Picture continued from opposite page. Two vivid flashes from the enemy ship and two shells “straddle’’ the target, one just short and the other just over —a perfect shot for range. After striking the water the shells ricochet and bound two hundred feet in air se ee ee ee 409 410 pay clerk to his assigned post, bluejackets and marines to the ammunition passages and their hoists. There is not a man aboard who has not his post, and down in the hull of the ship are the men of the engine-room force ready to give her every ounce of needed power. Every man who passes has a patch of fleecy cotton peeping out of his ears and as you dig in your pocket for some, a blue- jacket halts long enough to caution you to pack it in lightly and not to hold your hands over your ears. The turn of your ship to fire at its target has not yet come, but off to port or star- board you see a vivid sheet of flame leap out from the turret gun of another ship that is on the range. A cloud of smoke hugs the water alongside her and a great roar grows with each second. It is like the thunder of railroad engines, racing at full speed over a bridge. You see her shell strike the water and throw up a geyser of white foam. smaller geysers rear their white colamns when the shell ricochets, skimming across the sea in bounds as a stone thrown by a lad skims across a mill pond. A still more thunderous roar comes across the water when a salvo, or broadside, is let loose and each shell, as it strikes, sends up its whirling column of water. So far you are but an idle participant in the great game, watching it at a safe distance. Your ship is at last on the range and the order to fire has been flashed to one of the turret guns. A mighty blast rocks the mass of steel beneath your feet and it slides to port-from the drive of it. The military masts, for all the world like inverted waste baskets, whip over to one side like a bent fishpole and you grin and try to affect the calm of a true sailorman. If you have been alert you have caught fleeting impressions of vivid white sheets of flame, great blurs of orange-colored vapors, and you grasp the nearest support and strain your eyes toward the target. The ‘‘spotters,’’ with eyes glued to their On beyond it other and Popular Science Monthly glasses watch for it too, and pass below their judgment of the range. If the range is good the first salvo will tear the water -near the target into boiling geysers. The new smoothly-running motorcycle from which the vibrations have been elimi- nated, and the cross-sectional view of the motor, showing the placing of the cylinders 427 What Poor Pavements Cost the Automobile Owner Y running an elec- tric delivery wagon over pavements and measuring the amountof power required at dif- ferent speeds the condition of the pave- ment and its resistance to traction have been ob- tained. At the rate of twelve miles an hour it takes twenty per cent more power to run acarona poor asphalt pavement than ona good one. On a poor, soft macadam pavement it takes one hundred and twenty-five per cent more power. This taxes each owner about twenty-five dollars annually for roads. x Eliminating the Bumps from the Motorcycle Ride NE of the largest American motor- cycle manufacturers has just brought out a stock model equipped with a hori- zontal opposed motor, which is designed to reduce vibration and thereby provide a smooth- ly running motorcycle as) atallspeeds. The two- cylinder, four-cycle mo- tor has its cylinders placed fore and aft. As shown in the accom- » panying cross-section icponr. View of the motor, pFMoioR =the crankpin ends of the connecting rods are attached to a one-piece balanced crankshaft. By this method of cylinder plac- ing, the vibration set up in one cylinder by the reciprocation of its pis- ton is offset by that in the opposite cylinder, and in this way the jolting of the motor- cycle is avoided. MAGNETO Popular Science Monthly age onan oe A Mechanical Masterpiece Is the Caterpillar’s Wonderful Foot VERBODY knows the caterpillar’s ability to cling, yet few persons take the trouble to see how it clings. Its body is made up of thirteen segments, on the first three of which are six true legs. But it is not with these that the caterpillar clings. On the ten abdominal segments there are a number of tubular appendages which might be called “‘pro-legs,’’ each of which ends in a circlet of small hooks, the last two being claspers. At first glance the accompanying illustration might seem to be of a series of feet, but it shows only one foot. The caterpillar in its transformation discards some of its legs and keeps only four. The rear ones are pulp-like, yet they are interesting structurally though not quite so much so as the front legs. The front legs of abutterflyora moth have 4 4 evidently been transformed from the front legs of the larva. The butterfly never walks, probably because its legs are always weak, being merely sup- ports during rest; but the front legs are not used even for resting. In the larger and heavier species the legs do not bear the weight of the body at all, since the butterfly clings to the underside of a leaf or. twig and depends entirely upon This looks like some strange vegetable growth, but it is merely a caterpillar, with its tubular legs, magnified How to Make a Hanging Window Garden of Dis- carded Sponges Ae is such an ugly thing as it grows flabby from service, that it seems almost impossible to think of it hanging in a bay window or other favored spot as an object on which to feast one’s. eyes. But the fact is, that you do not feast your eyes on the sponge, for it is completely hidden from view. under a mass of green grass, or better still, of moss, from which you have coaxed hyacinths, tulips, crocuses or narcissi to peep and pour out their fragrance. But the sponge is there and is a most important part of the arrangement. It should be of rather large size. It need not be old; but an old one will serve the pur- pose as well as a new one. It should be looped around with strong twine or copper wire with lengths extending at the top as a means of hanging it, basket fashion. Now soak it in water and insert your bulbs, two, three or four to a sponge according to the size. Chink it over with moss, if you can, or sprinkle it generously with grass seed as a second choice. From now on the sponge must be kept damp but not wet, and in a dark or shady spot. As soon as_the shoots begin to appear the sponge may be taken from its hiding place and hung in the sunlight. the power of suction of his pro- legs and their hooks for support. At right the sponge is shown with the bulbs just planted. On the left the hyacinths have blossomed Popular Science M ‘2 ATobacco-Pouch and Purse Holder Combined POUCH which contains three compartments, one for tobacco, one for money and a third for stamps, has been invented by Charles J. Hathaway, of Walsall, Eng- land. The tobacco is carried in the circular compartment which forms a base for the entire pouch. Next is the purse, equipped with a flap, and on the outside is the small pocket for stamps. An outer flap folds over and entirely closes the pouch. Supporting the Arch of the Foot with an Extra Heel OCTORS affirm that a great many persons suffer from nerv- ous disorders which arise from slightly abnormal conditions of the feet. These persons unknowingly have fallen arches and the nerves of the legs, stretched as they are, can- “not perform their operations normal- ly. Since these nerves are connected through other nerves with the brain, such a condition may result in any one of the nervous disorders. A second heel attached to a shoe would prevent this occurrence by serving as an arch-supporter. An arch- support of the kind devised by Peter Broadbrooks combines the Each of the three com- partments is self-locking and entirely independent ; ‘\ A) . = onthly 429 to the base-plate. Into this a solid cushion of rubber is permanently fastened, and at- tached to the bottom of this is a metal plate to give longer wearing life to the cushion. A sleeve of this type is fastened to the shoe, and if the proper height has been selected, it ought to be more comfortable than it ever was before. A Snake-Bite Proof Ma- terial for Soldiers’ Leggings HE needs of the soldiers in the trenches and else- where have furnished inspira- tion for numerous inven- tors. Dr. C. E. Rogers, of Covington, Va., would make the sol- dier’s life easier with a new type of military legging made of vulcanated . rag-fiber material, coating which renders it absolutely waterproof. only material which a snake’s fang cannot penetrate. The legging is fitted in at the ankle and is shaped to conform with the calf of the leg. It is adjustable at different points of the length to insure a snug and comfortable fit. edges overlap and a special clasp is provided which includes slots in the underlapping edge. Spring keepers, with enlarged heads, are riveted treated with a It is claimed to be the The fastening in the overlapping part of the leg- ging. These slide into the corres- ponding slots and are secured by metal strips. The clasps are unlocked al- most instantly when desired by means of aneyelet and button. The button moves within the eyelet and is connected with the spring keeper by means of a flange and coiled spring. To open the legging it is necessary only to press the button against the spring, so that they are taken off or put on in a moment’s time. Although designed to meet the Special need of the soldier, the leggings can be worn by hunters and equestrians generally. They are very light in weight and in spite of their impenetrability are very flexible. They are said to cost about one fourth as much as the ordinary leather leggings. The vulcanated material is adaptable for other uses also, but leggings are the only articles that have as yet been made from it. advantages of a ‘“‘built-in’’ with those of a detachable supporter. The type shown in the illustration cannot move about under the arch while, like the detachable kind, it can be adjusted to meet the requirements of the wearer. The device consists of a The legging is adjust- able at different points of the length to in- sure a snug fit base-plate placed in front of A the ordinary heel. steel sleeve having the form of a short tube is threaded at one end so that it may be screwed The second heel serves as an arch supporter Are You a Good or Poor Penman? If you can’t judge your own handwriting here is a scale which will do it for you By M. McGuire Telford i ki i al u (60) 20 (6s) 30 50 40 (7s) 50 =| . ~ An fl Tnm 82 ta a Btwn tony ureths apg Pere Rerrnne, J hes to omaher Ak pee anne ov MY rhe ta, arena Reaen § H @ Orme & he as : nl ert Pi Spee Se ca se Ant Why vig, tu Son Vittles ti Wha trmmenfat Cont Serene i : how bans gow Barty Spot Tote Main eden + Gu © Sauna freasit altindeang Ze. ‘ p : Ze a Ae Oe Z 21 be es ee Ed “Gite Aonkel (203 ~~ > Lp . a7 x Bifloe ECL 8 ENTE enced Sy or AEN Fasc al mua Mrmr Uy Jn To measure the quality of a sample of handwriting, slide it along the scale until a writing of corre- sponding quality is found. The number in black at the top of the scale above each column represents the value of the writing being measured. Proceeding from left to right note how the samples improve i ©) 60 (es) 70 20 80 es) 90 I en esti 9 Yen Ya thmwary Avrora 4y sb Miton dt Pre! bosstion of "gama Rew York ce: Sundey OF was clerrclecl to gave Ahem thew w Later ow im Tpincfot the Cok x Examunad moune? weld save him hoPur tramnchsSammnenand L£ amuthy Austery dy ths fin seam Moar ore Cig Ct 1 Sb wells avery malt; tour hours at Puch: frst thamnmeatow wore avkuds te udumbify Bow dates uel al Columba ¢ beraene ak | Ee ee s STANDARD chart prepared by the > Russell Sage foundation in New York city and distributed at a nominal price enables any person to judge easily and accurately his own or another’s hand- writing. The scale is on a sheet of heavy paper measuring nine by thirty-six inches. It contains, twenty-four samples of writing of eight different degrees of excellence. These are of three slants—vertical, medium and extreme. Each of the three slants has eight samples for the eight different grades. Proceeding from left to right each sample is better than the preceding; moreover, the gradations are equal. The samples are marked at the top 20, 30, and so on up to 90. In actual practice, however, writing is usually marked on a more liberal scale. Grades ranging from 60 to 95 are indicated in the circles at the top of the same samples. The three slants on the scale include more than 95% of the ordinary writing of adults; in fact, 65% of all the samples studied are included in the medium slant. In measuring the quality of a given sample, the method is to slide the sheet along the scale until writing of similar quality is found on the scale; then a glance at the top of that division tells the grade. Where many samples are to be marked, as in school or other examinations, two methods are used. The first is to compare each sample with the chart as AON Te £0 ed. dare the SPF waar eS: Beery hid 00 next in importance between the lines. | sample 60, 70, and Popular ‘Science M onthly described. The second, which is more accurate, is to put the papers into piles of about the same degree of excellence and then. to compare the specimens in each pile with one another and with the stand- ard. Still more trustworthy results may be - obtained by having three persons work simultaneously by either of the above methods; at least two should agree upon . the rating. ; The preparation of the scale involved many difficulties. This was especially true. in getting equal gradations between the eight divisions. Since writing is intended to be read, legibility was made the basis; it is a striking fact that as legibility improves so does appearance. The legi- bility was determined from the length of time required to read the sample under consideration. In all 15,789 accurately timed readings by ten paid investigators were made with 2,817 different samples. An analysis of samples of writing making a good appearance, but having a low degree of legibility as shown by the tests disclosed the fact that the most common short- re comingis the crowd- ing together of words on a line; 3 is too little space Lifting the pen in _ the middle of a word so that the _ word looks like two - is also a common - fault that leads to illegibility. Failure to dot the “‘i’s” and cross the “‘t’s’”’ also tends to make read- ing difficult. Some writers insist upon abbreviating the - simplest words. In using the scale it may happen that _ three judges will rate the same MAGAZINE ROD RN. TRiccER = Se ‘Mj \ Y BREACH UamMER See ae _ 80. It is possible, however, to come nearer to securing uniformity of grading q with the chart than without it; and so far as is known no other equally effective and _ time-saving means has yet been devised for _ the purpose. ” SPRING CARTRIDGE # ee a § ~ #i ray The component parts of the miniature pocket revolver and the manner of using it. 431 A Pocket Revolver No Bigger Than an Ordinary Watch REVOLVER small enough to be carried in the vest pocket and fired when concealed within the hand has been invented by a Frenchman, Turbiaux. It differs completely from anything that has hitherto been made. Moreover, it has most of the refinements of the larger weapons, such as a safety device, a ten- cartridge magazine and a device which secures a perfect, registration of the cart- ridge chamber with the barrel. Briefly described, the revolver consists of a steel box, circular in form, within which is the magazine, hammer, trigger and safety mechanism. Lugs on each side of the barrel serve as bearing points for the fingers of the hand. The-trigger is a pro- jecting portion which fits against the base of the thumb. Two rods connect it with the internal mechanism. When the trigger is pressed the lower rod operates the ham- mer, causing it to strike the cartridge; the upper rod moves the maga- zine. To secure perfect registration of the chamber _with the barrel the trigger is pro- : vided with a rod which engages notches on the circumference of the magazine. On top of the weapon is a sliding safety- bolt, which, when pushed toward the trigger, locks it and thus prevents an ac- cidental discharge. To load the revol- ver, the safety-bolt is pushed forward, the entire cover is taken off and the weapon turned to one side, whereupon the magazine drops into the hand. The cartridges are intro- duced from the cen- ter, the magazine is returned to its posi- tion, the cover is re- placed, and the revolver is ready to be fired. Even when the ammunition is ex- hausted, the little revolver will still serve as a protection, for the barrel may be used as a handle and the other part as a hammer for delivering terrfic blows. DEPRESSIONS cane eo 432 Popular Science Monthly A Doll Which Is Meant To Be Abused Wind a Spring and Let the Pugilists for the Sake of Exercise UGEN SAN- DOW, the pro- fessional strong man, hasinvented a phys- ical exerciser which takes the form of a doll or figure. It is hung on the wall and _bat- tered into submis- sion; its legs and arms are pulled at will without caus- ing it any incon- - venience. The. inventor plans to supply the child with a doll that can be turned into an unconscious exercising medium. The ordinary rag doll is easily dismem- bered. Mr. Sandow’s doll is elastic and will thus with- stand any amount of youth- ful pulling. ~The arms and legs of his The oN a legs of the doll doll consist of coiled springs cubic mi = set ree with handsand feet attached. Fight It Out ITH the season -for mechanical toy novelties in full swing, the one in- vented by Charles E. Keffer, of Mem- phis, Tenn., will doubtless arouse interest. It is an The two figures are the toy causes’ them to approach each other only - their heads. touch. But the force of :the contact is so great that the.con- testants rebound briskly. They go at it again and again, however, as long as the referee, whois the youth- The covering fabric is securely fastened to ful owner of the toy, cares to prolong the these coils. The child can grasp either the fight. hands or legs and pull away at them without One leg of each of the figures is pivoted tearing them from the body. The fabric on the body so that in the rebound move- stretches with the springs. Con- venient grips are provided at the hands and feet of the doll. An exercising harness to be fitted over the doll or figure has been provided by the inventor. The hand grips, con- sisting of dumb- bells and_ elastic cords, extend just a little beyond the doll’s hands and feet. This toy is a veritable “strong doll” and will hold its own DOVE PIVOTED ARM AND LEG RECIPROCATING ments it seems to step backward. The arms are also pivotally attach- ed, but they have no other part in the affray than to give a lifelike ap- pearance to the fig- ures. The fighting is done by the heads alone in true billy-goat style. A hollow stand is provided which conceals the mech- anism and serves as a platform for the fighters. under the most _ TAL ‘ rT Around the top of ZS BLOCK P violent abuse Seone SPRING this, ropes are ex- which a healthy One foot of each of the pugilists is attached to a tended, making a child can inflict. staple connected with the mechanism underneath regular “ring.” animated butting match, between two. darky ' pugil- ists and depicts a favorite sport among’ the Southern negroes. connected ona slid-. ing-block in such-a_ way. that when the - interior mechanisni of - - oe ee oe ae ee re ee ee ne 5S Ears Be i a ae ee NS a a a Motion-Pictures on Glass G. Bettini, the distinguished inventor, substitutes glass plates for celluloid film and thus gives the motion-picture industry a new turn ce ' ‘on ee =) EEE EALAS Ue 6 er S ~: ee Shestteoeroneos iy 5 Sy Se Se AV AYE “SS ere Ceeeeere V2 + $$ 5 a Se ee ay ee a a mo x @ ers Merebe iA The glass plate substitute for celluloid film. The images are each one quarter of an inch square, and there are five hundred and seventy-six images on each plate. One glass plate is equivalent to about seventy-five feet of standard film. At the right is Mr. Bettini and his projector, with the plate in position for showing motion-pictures SS gata HEN a cheap, durable, non-inflam- WV mable substitute for the ordinary motion-picture celluloid film is found, we may expect to see motion- picture machines enter our homes and take a place beside the phonograph. So long as prints pictures on disks from standard film subjects, and a mechanical printer which makes square glass plate positives from standard film. The glass plates which Mr. Bettini sub- stitutes for celluloid films are the same as the cost of film is excessive, as it is at those used ordinary photography, the present, and so long as size being approximately the film is inflammable, LANTERN : five by eight and a half as it always has been and Sie. amt 5] inches. The images, ar- may continue to be, it will be - veers | ranged in vertical and hori- difficult to popularize home as] | zontal rows on a plate, are motion-pictures. — ere each one-quarter of an inch To overcome these diffi- PRISM sae square. There are five culties, G. Bettini, of New oe hundred and _ seventy-six York, has invented several images to each plate, which cameras and projectors in which ordinary cheap glass plates take the place of the jection. The Bettini principle of pro- The light from the is equal to about seventy- five feet of standard film. The developing of the nega- usual expensive film. For instance, he has evolved a motion-picture camera that utilizes glass plates in place of the usual film; a motion- picture projector for the home which uses the same glass plates; a second projector which utilizes circular a machine which non-inflammable disks; lantern strikes the prism and is there bent at right angles toward the image on the plate. Passing through the plate it enters the- lens to which the prism is attached, and is thrown on the screen 433 The glass plate is moved downward, row at a time, while the camera Jens.or the lantern lens (the lens for taking the picture tive plates and the printing of the positives is as easy as in ordinary photogra phy. The Bettini principle of taking and projecting pic- tures is novel yet simple. one 43.4 At left: The Bettini camera with plate-holding magazines in position for taking motion- pictures. The amateur may make his own negatives and develop positives for pro- jection upon the screen. A special device can be fitted to this camera for taking photographs Popular Science Monthly SBE At right: The disk projec- ’ a . tor intended as a toy for children. Here the mo- tion-pictures are printed on a flexible non-inflam- mable disk instead of on glass. The disk may be held stationary for any length of time required for a detailed study or adjust- ment of any of the pictures and the lantern for projecting it on the screen) are moved across each succeeding row in the opposite direction. In other words, the lens or lantern is moved from right to left across the first row of images until it comes to the last square, when the glass plate is automatically fed downward to bring the second row into position, and so on until the plate has been used. The feed of the Bettini apparatus is so constant that the pictures are projected with very little flicker. The synchronizing of the plate movement and the lens move- ment is so perfect that there is no ‘“‘jumping’’ when the glass plate is shifted down from row to row. Further- more, one plate may quickly follow another, so that the longest picture may be pro- 74, combined camera which the prism is attached, and once more the ray is deflected at right angles so as to be thrown upon the screen. | Any image on a Bettini plate can be enlarged and printed in afew seconds. The plates may be run backwards, thus afford- ing no end of amusement. Circular sheets of non-inflam- mable material may be used instead of glass plates, and cir- cular and square plates may be made from standard films. A Trip to the North Pole by Submarine S early as 1899, Mr. Simon Lake, the inventor of the “Lake’”’ proposed and. planned a sub- type of submarine, jected as easily as with the celluloid film. The optical principle of the Bettini plate camera and pro- jector—the principle on which and projector. The plate movement and the lens movement are so perfect that thereis no “jumping” when the plate is shifted down from row to row marine for sailing under the ice of the Arctic waters to the = North Pole. It was realized that this way of traveling would save an explorer many all the patents are based— may be understcod from the accom- panying diagram. The objective with its prism is mounted on one side of the plate, while on the other side is a second prism on the longitudinal axis of the lantern con- denser. The light from the lantern passes through a condenser, strikes a prism and is there bent at right angles toward the image on the plate. Passing through the image on the plate it enters the lens to tedious months and would in- crease the assurance of his reaching his destination. But the submarine was in its — early stage of development and the carry- ing out of the plan never got much further than a few experiments. The extensive im- provements in the submarine since that time, however, have again brought this mat- ter up for serious consideration. The sub- marine required need not be very much dif- ferent from the Deutschland, it is said. — a ae ee i a las Sie et ia etl ao: a & SNR eV ky Popular Science Monthly Building a Street Car Line Without Stopping Work or Cars HERE are streets in con- gested districts of some of our cities where both vehicular and car traffic is so dense that even stone ballast will not prevent the “work- ing” of the railway ties, and as a result the paving in the railway area and adjacent thereto is ruined. To avoid this, the concrete should be used under the ties. “‘How can the concrete be put under the ties with the least trouble, expense and in- terruption to car traffic?’ A novel way of doing it has been tried out and proved feasible: First, the track work is brought to the correct grade and line, using the ordinary crushed stone ballast under the ties. Then, from a small continuous mixer, placed just far enough from the rail to permit cars to pass, a thin cement grout is conveyed in chutes to the ballast. The grouting mixture is composed of one part cement and two parts sand, at about the consistency of thin cream. By the use of a flexible chute in two sections the work is carried on without the slightest interrup- tion to car traffic. When a car comes along, the first section of the chute is thrown out of service and the second is lowered to the ballast, and so on. —— — see eee The frame of the coal meter slides into a recess 435 A Meter for Registering Amounts of Coal Used in Power Plants NE of the principal fac- tors in the success of a power-plant is the ability to control the quantities of ma-. terial used in the production) of power. It is neces- sary to know how much water is evapo- rated per pound of coal and just how many pounds of coal should be used for each horsepower. In order to get such statistics, a coal meter. has been invented, which con- sists of a recorder driven by the passing of the coal in such a way that its movement is proportional to the rate of flow of the coal. The recorder can be made to register in any units desired. The meter was designed originally to check up the boiler room performance of a large railway plant in the hard coal fields of Pennsylvania, but it performed its task so satisfactorily that it was decided to build it for general boiler-room use. To install the meter, a rectangular slot or window is cut in the chosen pipe as shown in the illustration. The meter is then inserted “‘ribbon end”’ first, and dropped into place. No bolts, screws, rivets or fastenings of any kind are required, as the frame is made with a recess which grips the pipe firmly and prevents the meter from slipping out of place. The face of the recorder is conveniently located on the outside of the pipe, so that it may be easily read. Thus ac- curate information may be obtained as to how much coal is required for a given amount of energy, and statistics are found that help in estimating the upkeep of the plant. Other advantages of this type of coal meter are the durability of its construction and the little attention which it requires to keep it in perfect working condition. There is Me =* wv > A flexible chute in two sections is used so that traffic is not interrupted while the cement mixture is being deposited nothing about it to get out of order. 436 Filling Twenty Coal Bags by Elec- tricity in Four Minutes NE man and the coal-bagging ma- chine shown in the accompanying illustrations can fill and stack twenty bags in four minutes. In many cities with a large number of private residences without suitable driveways coal is delivered in bags. In such cases bagging the coal by -hand has always been slow and expensive. To eliminate this cost the machine shown herewith was designed. It consists of a small three-wheeled vehicle having an inclined screen, small bucket-conveyor and a mechanical feeder which automatically pushes the coal to the bottom of the elevator. The machine is chain-driven from a small electric motor beneath the conveyor, receiving its current from the available lines in the yard. In operation, the ma- chine is backed up into the base.of the coal-pile, the feeder is lowered to the surface, a -bag is placed on the bottom of the’ screen as shown, the current is turned on and the clutch is thrownin. After this the opera- tor has nothing to do but remove the filied bags and stack them. The feeder is suspended on counter- weighted cables so that it adjusts itself to the surface of the pile. It is provided with a metal hood to. prevent clogging in case of a pile slide. Four removable screens are furnished. Popular Science Monthly Atleft: The three-wheeled vehicle with inclined screen, bucket conveyor and mechanical feeder Below: The machine in operation. The feeder is suspended on a cable and adjusts itself to the pile Put Pneumatic Tires on Your Hiking Shoes AKING his inspiration from auto- mobile tires, and going the ordinary rubber heel one better, Mr. Oscar Mussinan, of New York city, has invented a pneumatic tire for his own shoes. The “tire’’ differs very decidedly from the ordinary heel in that a partition of rubber is built in it half way up its thickness. The partition thus forms an air chamber with the bottom of the leather above it, and still another one with the ground when the heel comes down upon it. Each of these two chambers is connectedwith the out- sideair by asmallopen- ing. When the heel strikes the ground, the air in the chambers becomes slightly com- pressed causing the jolt of the walking to be very greatly cush- ioned in a manner very much similar to that in which the automobile tire cushions the jolts of riding. To pre- vent the air from be- coming too suddenly compressed and so putting the bottom of the heel out of shape, the air is allowed to escape slowly through the openings during these compressions. PNEUMATIC CHAMBER CENTRAL PROJECTION DEPRESSION SSa WS 72 SSS NS PERFORATION VENT A rubber partition is built half way up into the heel. This forms an air cham- ber to cushion jolts Popular Science Monthly Strap Your Purse to Your Thumb. No One Can Steal It Then SYCHOLOGISTS and criminologists have asserted that the carelessness . with which people handle their purses and expose their val- uables on the street or in public places is responsible for a great majority of thefts. The temp- tation to steal is thrust under the very noses of those who are not inclined to resist. The wearer of the purse in the accom- panying illustration need not face such an accusation, for it is provided with a strap which holds it securely and leaves no opportunity open for a thief or pick- ass ped ei asses ar pocket to make off {re cena. with it. Not only does it embrace the hand, but the strap also passes over the thumb, so that the purse can not slip from the hand even when the fingers are relaxed. By this ar- rangement the weight of the purse rests on the palm, just as though the purse were held in the hand in the ordinary man- ner. Yet the hand and fingers are perfectly free to be used for other purposes. The purse itself is two-fold and has com- partments for bills, cards, change, a mirror and the inevitable powder and puff. The handkerchief may be tucked under the thumb-strap, for safe-keeping. fastening over the thumb Nursing Orphaned Animals with a Tin-Can Mother . Se old saying that you can lead a i horse to water but you can’t make him drink isn’t any more truthful than the statement that you can lead a hungry colt or a calf to a pail of warm milk, but you can’t make it drink. Not because the youngsters are stubborn, however. They are willing enough to drink the milk, but they don’t know how. That is one reason why inventors have been busy devising 437 some sort of make-believe nipple to attach to the milk pail—a nipple that may not work as efficiently as the hungry calf might wish, but which will answer the purpose nevertheless. It looks as though Charles E. Johnson, of Fond Du Lac, Wis- consin, had come nearest to the _real nipple with the suckling de- vice illustrated. The automatic nipple he has constructed is at- tached to an ordinary milk-pail. In operating it the young animal grips the forward end of ‘the ‘nipple in his mouth and closes the front sections upon each other, thus releasing a tube at the rear end of the nipple to permit the milk or water to flow freely. Whenever pressure is released on the for- ward ends of the sections of the nip- ple the supply is checked automatic- ally by the action of a bow-spring. The liquid flows out of the nipple only during the - time the animal is suckling or pulling it. An oil heater is placed under the milk container inside the pail, as shown at the upper left of the picture, to keep the milk warm. Her mother is a tin-can hung from a nail in a post Electric Steel from Electric Furnaces We were forced by the exigencies of war to develop our own crucible-steel industry. LECTRIC steel is now a commercial E success, and the United States leads the world in its production. Until it became possible to melt and refine steel by the use of electricity as a source of heat, instead of gas or oil, nearly all steel was made either in crucibles or small pots, or in large coal 4 or oil furnaces. Large f furnaces, known as open- hearth, today still make the majority of the steel produced in the world, but it is the electric steel furnace which now makes the best and purest steel, rapidly displacing that made.in small crucibles, hitherto the best for tools, razors, etc. . The unusual qualities possessed by electric steel are not bestowed on it by the electricity itself. This should be clearly under- stood. The conditions are responsible rather than theiagent itself. In other furnaces where oil or gas and air are the _heat- producing mediums, there is more or less contamina- tion from impurities, such as sulphur, as well as from the oxygen of the air itself, too much of which is often harmful to steel. But in the furnace, electricity is an even and very intense source of heat; the conditions can be so regulated that the air or oxygen has but little effect on the steel. Practically no contamination is possible. Also the temperature is so high that more refining is attainable than in any other furnace. In other words, certain chemical reactions can take place so as to remove objectionable elements—an impossibility in other steel-making furnaces. One of the qualities that distinguishes electric steel is its greater purity. Hence it is stronger than other steels. Compare it with any steel made by any other proc- ess and of the same composition, and the electric steel will show greater strength. Many steels are susceptible to change from Tapping molten metal from an electric furnace. from it like water from a tub Now we lead the world frequent shocks. Some give out and break down before others under such conditions. Again, electric steel is superior to others in this respect and is now used in many places where shocks must be withstood, as for automobile axles, springs, etc. Electric : steel is also very uniform in composition and is denser than other steel—both im- portant qualities. Steel made by the usual and older processes also con- tains varying amounts of certain gases included in them, strange as this may seem. Electric steel, however, is very free from these objec- tionable constituents. Europe and _particu- larly Germany had al- ways led in the use of electric furnaces for mak- ing steel until the war started. Development in this country had been very slow partly because electricity was high and partly because there was not a large demand for such a high grade steel. The actual need was sup- plied by importations from Europe. As the war progressed and electric steel could not be imported when: needed we were forced -to develop our own electric steel industry. In addition plumbago crucibles, with which crucible steels, then the high grade steel, were made, advanced so in price and became so expensive and hard to get that crucible steel makers were driven to the electric furnace. Today in this country all but two or three crucible steel castings makers are now using electric fur- naces instead of crucibles and would not change back to the old process if they could. Their product. is better and more easily made. Tons are made at a time where formerly it took over twenty crucibles to make one ton. The expansion in this branch of the steel industry in the last six years in the world and in this country is astonishing. Steel flows 438 Se ee Ee yea eo en At Last! Electric Steel Is Here The electricity after passing through a system of connections and transformers enters the furnace through the three large carbon sticks or electrodes which can be seen issuing through the roof. This particular view shows a six-ton furnace. Into it, when hot, either cold scrap iron or steel or sometimes molten pig iron is put and the electricity turned on. In three or four hours the pro- cess is completed and the steel is ready to pour. Tons of electric steel are now made in a single furnace where formerly it took over twenty crucibles and much time to make one ton 439 Imitating an Imitation Japanese craftsmen have for centuries made fortunes by cleverly charring sugi wood to imitate driftwood. Americans are now applying the process to our own cypress : By Robert H. Moulton own specimens of so-called ‘‘Japanese driftwood,’’ which is not driftwood at all, but clever imitations made from the sugi tree. For many centuries Japanese craftsmen have plied a_ thrifty trade in this wood. In the be- ginning they gath- ered genu- ine drift- wood from the sea and turned it to uses of beauty without treating it in any way. Its embossed-like surface _ was due to.natural agents. The chemical action of the salt of the sea and the long-continued churling of the waves ate out and carried away the softer parts of the wood and left the harder grain. However, the supply of driftwood was limited, and its evolution from the fresh wood by the action of the sun and the sea, covered a long period of time. The crafty Orientals then conceived the idea of pro- ducing artificial driftwood. This was ac- complished by charring the fresh wood with fire and then by rubbing it with rice-straw. The artificial driftwood had all the appear- ance of the genuine, and it was long before the imposition was discovered. Finally, however, a noted scholar and - traveler, the late John S. Bradstreet of Minneapolis, discovered the secret. He then set about to find an American wood capable of tak- ing the sugi finish. After many experi- ments Mr. Bradstreet discovered that cypress was practically the only one that OO crea coon a good many of us would stand up under the sugi process. The process of treating cypress to secure the sugi finish is so simple that it can be carried out by any one. necessary are a gaso- line torch of the kind used by plumbersor painters, an f The process con- sists simply in char- ring the wood with scraping it after- ward with a steel wire brush and pol- ishing it by rubbing ordina- ry steel- wire brush, and a small scrubbing-brush. The torch should LRP atsigiad) have a large and exceedingly hot blue . flame, since success in securing the desired effects depends largely upon the speed with which the burning or charring of the wood is done. Cypress wood, like the wood of the sugi, is close-grained, and, when cut into flat sawed boards its ap- pearance is very beautiful. growth is much harder than the summer growth, and when heat is applied it merely discolors the harder grain while the softer summer wood is completely charred. All the charred portion is then brushed out by the wire brush. This leaves the wood entirely covered with a fine powder which must be removed with the small scrubbing-brush. Cloth should never be used for this purpose as it has the effect of rubbing the powder into the wood. Charring the wood properly is perhaps the most difficult part of the work, although it is also important that the rubbing be done evenly so that the tone will become uniform. The more the soft grain is rubbed out, the lighter will the general tone become. 440 The only tools - a gasoline torch, The spring | ig ABSA Ri eer RG rn i gi a gil enc aa Sat NG abi oee U i> ie en | ae et rs ye Eg SN a i —-— - TFOR PRACTICAL WORKERS A Pliable Metal Screen Fabric as a Substitute for Glass FABRIC which has the strength and lasting qualities of metal and which _may be bent to any shape and used as a substitute for glass in windshields, as screens for lamps and lanterns, and for many orna-~ mental pur- poses may be easily prepar- ed from ordi- nary mosquito netting and glue, colored according to taste and to the use to which it is to be put. Take 2 oz. of gelatine or glue and let it stand for one-half hour in 32 oz. of water, then place the vessel containing the glue in a saucepan of boiling hot water and let it remain un- til the glue is melted. Do not try to hasten the melting by setting the vessel over the flame, as this will spoil the setting properties of the glue. Strain the liquid through wet cheesecloth into a heated tray. Have at hand several pieces of mosquito netting, 6 or 8 in. wide, and cut across the entire width of the roll, which is usually 30 in. wide. If this netting is previous- ly coated with nickel or zinc by electro-deposition it will make a stronger fabric. Grip the strip at the ends and pass it slowly through the hot glue, so that the formation of air spaces may be prevented. Suspend the After the netting has been prepared wat a : in this way it is non-inflammable sash. Large trays may be used and relatively large pieces of the net- ting prepared in a like manner, to be used for porch screens or sun parlors. strip for one hour or until thoroughly dried. Having thus prepared several of these strips, take each one singly, bend it into U-shape and pass it backward and forward through a solution composed of 2 oz. of 40 per cent formaldehyde and 32 oz. of clear water. Suspend to dry without. washing. This will set the glue so thoroughly that it will be insoluble even in boiling water. When the strips are dry they may be dyed any color with analine dyes. Common red ink will dye the fabric a brilliant red for the photographic dark- room and blue ink will furnish just the right shade for de- veloping paper prints. This fabric is light, pliable, fireproof and waterproof. It is semi-trans- parent and can be rolled up and packed away, and will lend itself to any number of uses. Owing to the pliability and texture of the material it can be readily cut into any desired shape or size to fill in a window 441 442 Magnetic Base for a Machinist’s Electric Light LECTRIC light has become the one illuminant for the machine-shop, be- cause it can be handled readily and moved to the best lo- cation for throw- ing the rays on thework. Hooks, arms and adjust- ers are many for this purpose, but the magnetic base seems to outshadow them all. It consists of a coil with a soft iron core which is con- nected in series with the socket. When the current is turned on in the lamp its base can be set in any position on a ‘machine-tool and the lamp will be held securely in that position by magnetic attrac- tion.—JESSE J. NACHMAN. The current in the coil makes the base magnetic The Protection and Care of Shop Belts HE best man in the plant should have special charge of the belts. He should be a man capable of using his imagination as to what a belt has to undergo on a drive. The belt swings around the pulley on the driving machine, and the strain on it rises from almost nothing in a tenth of a second to a pull of several hundred pounds as the belt leaves the drive-pulley on its trip to the shaft-pulley. a Suppose the belt is driving a machine with a jerky power driver, not balanced by a flywheel, and while the belt is tightly stretched under this pull it is violently jerked and tugged as well. This puts a big strain on the belt at the moment when it is least able to stand it. The belt for such a drive should be broad and thin, if it runs on a small pulley. When the belt reaches the shaft-pulley the strain drops to almost nothing, and it runs back slack to the machine-pulley. But, if this machine is not running smooth- ly, the belt is alternately let down and tightened up on the slack side, and each tightening makes a sharp, sudden strain which tends more and more to tear the belt to pieces the slacker the belt is, acting just like a whip in its sudden tautening. One Popular Science Monthly can readily see how this destroys the belt at the fasteners and joints. The size of pulleys makes a difference in. favor of belt service. The larger they are the less the strain and the better they hug the additional length of pulley surface. If a belt on 5-in. pulleys breaks down fre- quently, the pull on the same belt running over 10-in. pulleys will be just one-half, and the pulley adhesion just twice as great. Of course, the speed of the belt will be doubled. Furthermore, a double belt may be used on the enlarged pulleys to convey still more power, if necessary. Such a double belt would quickly wear out on the small pulleys. Carrying Two Large Cans of Water with Little Effort N a very old but flourishing mining town in California, a most interesting labor- saving device was seen recently. It madea comparatively easy task of carrying two 5 gal. kerosene-cans full of water. The device consisted of a light wood frame made of slats or thin boards, 3 ft. square, and braced in the corners. This frame separated the two containers from the The frame keeps the containers away from the carrier and lightens the work considerably carrier as shown. Practically no strength is required in carrying the load, since the tendency is for buckets or cans to come together instead of exerting a vertical strain.—AUSTIN ARMER. ee Sete ‘i be Ty ge aye eats cay DR ES Eh aT Sa eae Ee a ee en Rak tae _ satisfactory stencil. of its length. _ Then with a hot iron ‘ run over the lining to straighten it out. Cut ¥ eS ‘Popular Science Monthly Cutting Stencils from a Discarded Photographic Film HOTOGRAPHIC films, which are usu- ally destroyed when they are spoiled, make excellent material for stencils. Pic- tures or other designs to be stenciled may be pasted on the film and the outline cut out with a sharp knife. It is necessary to The stencil is cut with the dull side of the film down, to prevent it from slipping use care in selecting a design suitable for stencil work. For large designs it is neces- sary to leave binding strips to secure a The films are used with the dull side down to prevent their slipping. A large variety of designs may be made from pictures clipped from publica- tions of various kinds. Ironing a Four-in-Hand Tie Without Making Glossy Streaks 2 is not an impossible task to wash a four-in-hand tie: The difficulty comes in ironing it in such a way that its original shape will be restored. To do this it is necessary to proceed carefully. Start by placing the wide end of the tie upon the board with the seam up, then thrust in the finger and take hold ° of the lining. Grasp the silk cover in the other hand and pull it back from over the lining for about half a piece of stiff cardboard to fit into the wide end of the tie and long enough to reach to the narrow band. Slip this in between the lining and the seam side of the outer layer. Then dampen a clean cloth, lay it over the tie and iron in the usual way. The cardboard form will prevent the Pressure of the iron from causing a glossy mark to appear on the silk front opposite the seam. When through, put the form aside for another time —EmILe PARENT. 443 Pulverizing the Powder in Fire Extinguisher Tubes HEN the powder in fire extinguisher tubes becomes caked, the inspector usually empties the contents of the tube on a paper and re-pulverizes it with a crusher. It is more convenient to use a sifter like the one illustrated and screen the extinguisher powder through it. Take an ordinary one-quart flour sifter and a funnel of sufficient size to fit over the lower end of the sifter. Remove the spout of the funnel so that an opening of at least 34 in. is formed. -Make a cylinder of tin, slightly tapered toward one end, about 3 in. long and of sufficient diameter to fit snugly into the mouth of the dry powder tube. Make %¢-in. slits, about 3% in. apart, around the larger end of the cylinder and press it over the lower end of the funnel so that the flanges, formed by cutting, bend outward to conform with the shape of the funnel. Solder firmly in this position. The powder should be emptied from one of the tubes into a convenient receptacle. il RMU 0 pamenminee Attinu i , The ordinary flour sifter with a funnel at- tachment for pulverizing caked powder Then place the end of the funnel into the empty tube and sift the powder from a full tube into the empty one. Fill the last tube with the powder from the first one. Modern Conveniences on the Farm Inexpensive machinery for a lighting and water system. By H. B. Roth r NO have city comforts and conveniences in the farm home, it is necessary to have some kind of power. If there is a stream of any size, electricity is the cheapest power obtainable. Lacking this, a gasoline engine is the best possible solution of the problem. On a recently purchased farm in southern Michigan, the owner has made it his first duty to supply those comforts which are luxuries to many farmers, but absolute necessities to the family which has formerly lived in a large city. An adequate water supply being the first consideration, a 6-in. well was driven through hard-pan and blue clay to a depth of 90 ft. Good water was struck 20 ft. below the surface. However, the deeper well yields a continual flow of cool water of a superior quality. To convey this to all the buildings, an auto- matic pump which works by air pressure was placed within the 6-in. pipe. A large air-compressor tank run by the gasoline engine stands in the house sheltering the well. There is no storage tank for water. A faucet opened anywhere starts the action of the pump, and fresh water directly from the well is immediately obtainable. The same engine which pumps air into the compressor-tank runs the dynamo which charges a set of storage batteries furnishing electricity for the entire farm. By the same power corn is shelled and ground, alfalfa turned into meal, and the grindstone turned for the busy man. Even the exhaust from the engine is utilized. A discarded water tank is set on end beside the engine. The exhaust pipe is run into this tank, which radiates enough heat to raise the temperature above freezing. The extended pipe, connected with a rect- angular pipe-frame resting on the floor of the watering trough outside, prevents the water from freezing in severe weather. The water is piped to the house, supply- ing two bath-rooms, kitchen and laundry. There is also a hydrant furnishing fresh water in the pig-house which is also supplied with a large feed-cooker. The overflow from the well is piped to the hen- house where the water trickles into troughs made of galvanized eave drains that are securely fastened to the side of the house at the proper height. At the farther end of the 56-ft. poultry house, the water empties into a pipe which carries it 100 ft. or more to a trough in the colony yard, supplying another flock of chickens. The troughs are brushed out daily, and the flow of water is steady enough to insure coolness ~ and purity at all times. The water may be shut off within the engine-house on cold nights, and any coating of ice in the trough is quickly melted with a kettleful of boiling water. For baths, kitchen and laundry work, and the scrupulous care of milk utensils, a constant supply of hot water in the house is of great importance. The hot-water tank is connected with the hot-air furnace and laundry stove. However, it was not always convenient to keep a fire in the laundry stove, especially in hot weather. After much consideration, a blue-flame oil heater was installed, and that has given perfect satisfaction during the past year. It is used in connection with the laundry stove on wash-days, and alone at other times. After the water is hot, which is in a very short time, two of the three fires may be extinguished, leaving one burner lighted to insure hot water at all times. If the water is entirely cold, the three burners lighted will heat enough water for a bath in 20 minutes. The heater is simple in con- struction, easily cared for, and much cheaper and more convenient to run than a coal stove. Electricity lights the engine-house, poul- try house, stable, barnyard and residence. An electric iron is considered the greatest labor-saving device in the house. There are outlets in the kitchen where electric stoves may be attached, and a vacuum cleaner may be run on the same current. It is the owner’s intention to install an electric motor in the basement for the purpose of running the washer and cream- separator, as the engine house is too far distant from the residence to make use of the gasoline engine for these purposes. It is possible to have all the conveniences and comforts in the farm home at prac- tically the same cost as in the city establish- 444 Running a Farm with Gasoline and Electricity ; } j So] i ee ~ WATER PIPE = Below: The dyna- mo of the plant where the storage battery and switch board are found Above: The country residence sup- plied with light and water for all purposes from the farm power plant Left: . Power house plan showing loca- tion of engine, pump, switch board, gen- erator and water pipe from the pump Right: Ground plan showing location of the residence, engine house and buildings supplied with light and water Below: Outside of engine house which is an extension of a shed covering the water tank and occupies little space Sa yh ' ‘ SRR RT aR RER CO RD, Below: Theengine side of the power house in which an air compressor and tank are located 446 ment. The first cost for installing the machinery is the greatest expense. The up-keep amounts to very little, especially if the owner is fortunate enough to secure the services of an intelligent man-of-all-work, one who is handy with tools and can make ordinary repairs when necessary. On this particular farm the handy-man was the inventor of the tank heater for the engine- house and watering trough. He also fitted up the family surrey with electric lights, fitting the tiny bulbs into the lamp- wick sockets, and connecting them with dry cells placed under the front seat. A home-made switch turns on both lights at once. _Foot-Power Jig-Saw Made from a Sewing Machine N old sewing machine that had out- lived its usefulness in that capacity and was to be discarded made the ground- work for the jig-saw as shown in the illus- tration. The shuttle, the mechanism driving the needle-holder and the step were removed. Only the hand-wheel together with its shaft and cam-disk at the end were used. The frame of the jig-saw consists of two arms 21 in. long, 4 in. wide and % in. thick. Each piece is drilled through the width, making three holes, one 3/16 in. in diameter 1 in. from the rear end, one 15 in. from the same end, and one ]{ in. hole 4 in. from the opposite end or front end of the frame. A 1/16-in. hole is made in the side of the upper piece 4) in. back from the front end. The two pieces are held together at the rear end and 6 in. from the front end with bolts having long threads on each end and a “ABASE PLATE The frame of the jig-saw for attaching to the sewing-machine table and head for small jobs nut on both sides of the stick. The rear end bolt is made up of two pieces, each 214 in. long and 3/16 in. in diameter with threads on both ends, 14 in. in length on one end and 4 in. on the other. The shorter threaded end is turned into a hole tapped into the side of a round piece of Popular Science Monthly iron that is % in. long and 34 in. in diam- eter. The piece is also drilled centrally with its length for a 44-in. bolt. This bolt runs through a standard 10% in. long, % in. wide and 3/16 in. thick that is fastened HLA | ( fi The frame on the sewing machine where it is driven by a crank attached to the head shaft to the base plate of metal running beneath the sewing-machine top. This latter plate is 21 in. long, 114 in. wide and 4 in. thick. This is fastened to the top with a thumb- screw turned into a tapped hole in the metal sewing-machine base. In the outer ends of the saw-arms are placed screws which are centrally drilled for the saw-blade end and a set screw affixed to clamp the saw in place. The sawing table is made up like a three- legged stool, the top being a round disk 6 in. in diameter and 14 in. thick. To prevent the saw blade from lifting the board up at each stroke a guide is used above it. The guide consists of a 3/16-in. rod bent L-shaped, one end being flattened and the other having a long thread cut init. A bar fastened to the lower part of the square frame on the sewing-machine head makes a support for this guide. A short pitman is used on the cam-disk to drive the frame. The shaft and cam- disk are, of course, driven by the usual treadle, wheel and belt drive that was originally used on the sewing machine. While this arrangement does not give any great swing in the opening under the sewing-machine head it can be used ona great many pieces for building up small work.—E. M. Davis. How to ae PR VERY one is familiar with the musical __ F-_ tones produced by gently rubbing the _ ~—' fingers over the edge of a tumbler, the necessary preparation for producing the sound being moisture. The vibratory ac- tion is greatly augmented by acidulating the water, using the juice of a lemon, citric acid or vinegar. The illustration shows a device which is _ “easily made, wherein a dozen or more _ glasses can be used, the proper tone and _ pitch of each being determined by the amount of water which is carried in the _ glass. The music from such a group is exceedingly sweet and unlike that of any other instru- ment. The tones are considerably - improved by mounting the ism on a —__ box, which thus serves as a _ sounding board. Pes As herein _ shown the base = is simply a board, 16 in. long, and 8 in. wide, with a post at the rear corner of each ___ end on which is mounted a longitudinal bar, __ the top being 6 in. from the base. Parallel _ bars are placed 2 in. below the first one. _ These are slightly separated from each _ other, to receive between them the rear ends __ of the lower members of U-shaped key-bars. The key-bars are made of soft steel Strips, each 14 in. long, 14 in. wide and 1/16 _ in. thick. These are bent to assume a U- form, the upper and the lower members __ being parallel with each other. The rear _ end of the upper member is secured to the __ top of the longitudinal bar by means of two ____serews, while the lower member rests be- _» tween the two parallel bars mentioned. On the forward ends of these key-bars are mounted the keys for the musical scale, the natural scale being preferable, which keys are spaced equidistant from each other. _ The keys representing C sharp, D sharp, Keys representing the natural scale are used and clear musical tones are produced from the! glasses Ree Mechanical Crystal Chimes Tones produced by rubbing partially filled drinking glasses with revolving wheels By J. S. Zerbe F sharp, G sharp and A sharp are placed between the keys thus indicated. Before the key-bars are put into position two lin. holes are bored through each member, one hole 24% in. from their rear ends, and the other 5 in. distant. These holes serve as bearings for spindles, each of which is 2 in. long. On the upper end of each spindle is a grooved pulley, and on the lower end a disk, a little less than half the diameter of the top of a glass. On this disk is strapped a thick rubber band, of the kind which is wider than the thickness of the disk, so as to form a receptacle for hold- ing water on top of the disk when it is in position. An endless belt passes along the two trains of pulleys, starting from a power pulley which is operated by a crank. An idler pulley at the op- posite end, which is capable of being moved a_ limited - dis- tance, serves as a tightener for the belt by which adjustments are made. The tumblers used are of thin white glass, and these are arranged below the spindles so that a disk is within each glass, but fully 4 in. from the rim at the rear side of the glass. In that position a downward pressure on the key will cause the lower member of the key-bar to move to the rear, through its bearing, and thus bring the rotating rubber-tired disk against the inner edge of the glass. In mounting the glasses on the board they can be securely held by a coating of thick gum tragacanth. Water is put into the various glasses, and more or less added until the proper musical pitches are obtained. A mark is then placed in the side of each glass so that there will be no trouble in refilling them to get the correct tones. The disks may be turned by a motor or by an assistant. 447 448 The flexible character of the key-bars permits the operator to exert a greater or less pressure without materially affecting the movement of the rotating disks, and thereby enables him to accent the musical strains. The water used should be well Popular Science Monthly Handily Arranged Case for Holding Drawing Materials HE drawing shows the construction of a convenient case to hold drawing materials used by the draughtsman, pen and ink artist or student. The outside di- mensions are 5 in. high by 64 in. ~~ MANN SEZ TT = = ( iy 2 Bs wide by 11% in. long. A hinged cover 14 in. thick, fastening with a hook or lock is provided. One end is partitioned off to hold ink bottles. The partition near the front has a raised bottom so that the ink bottle in use will rest with its top almost flush with the top of case. This bottle should be wedged in. Instead of using the regular The revolving rubber disks may be turned by a motor or by an assistant to the person operating the keys acidulated and a quantity placed in the cup-shaped retainers on the upper sides of the disks. More or less of this water will flow over the rubber bands during their turning movement and thus constantly provide sufficient moisture to produce the best results. Electricity Used to Start a Balky Horse PENNSYLVANIA farmer who-owns a valuable horse, cured it of the habit of balking by using electricity. He pur- chased a small storage battery, connected it with wires to the bit and crupper and placed the battery in the cart to which the horse was attached. When the horse re- fused to move and stood with all four feet braced, the owner touched the button connecting the lines with the battery. The horse received a slight shock and he snorted and jumped and began to move off at a lively pace. Every day for a week he was given the same treatment. Asa result the balking habit was completely broken up. - Upon investigation the local Humane Soci- ety decided that a little electricity is better than a whip.—Mrs. C. A. WoLFE. filler-cap to close the bottle when not in use, the bottle is stoppered by means of a cork screwed to the hinged top of the case, as shown. The cap is kept. in. the’ back partition, a block with a hole in its center being provided to hold the point of the quill from the bottom of the case. Thus as soon as the lid is raised the ink is ready for use. While being used the filler cap may be kept in the bottle. Space is left in the middle partition for a spare bottle of ink with its cap. These bottles should rest on pieces of blotting paper to absorb any ink which may be spilled. Blotting paper is also placed in’ the bottom of the partition where the filler cap is kept. A shallow wooden tray is set into the upper portion of the main part of the case, _SECTIONAL ELEVATION SSS SS SSS Ee i PENS PENCILS ETC 5 DRAWING INSTRUMENTS ZO \ AAW, Hi PENHOLDERS _—________—___} — eee ; WORKING INK SPARE INK -FILLERCAP BLOTTINGPAPER__ ay oa A case with convenient compartments for all tools used in ordinary drawing work and is divided into four parts. Two are full length, to hold penholders and drawing pencils, while the remaining one is divided in two, one part holding erasers and the oe other penwipers. The pen and _ pencil _ spaces have curved bottoms to facilitate _ the removal of the pencils and holders. One side of the bottom part of the case contains a long tray with rounded bottom, _ partitioned off to hold different kinds of _ steel and other pens. The remaining space _ is taken up by two telescoping trays, the | upper one being shallow and_ holding _ French curves, protractors, etc., while the _ bottom tray holds the drawing instruments. _ When Jin use all these trays may be taken _ out and set at any convenient point. If the case is to be kept at the right side of the _ drawing-board, which is the usual place, _ care must be taken that the ink-bottle _ partition is located at the left side of the : x, as shown, as the ink will be much _ easier to reach—H. H. PARKER. — A Mixture for Removing Paint oe . From Wood 3 aoe very satisfactory paint removers _ J can be made by mixing up proportions _ of such substances as acetone, amy] alcohol, _ carbon bisulphide and ethane tetrachloride. _ Any one of these liquids will suffice and _ may be applied with a brush or made up in _ paste form and applied with a pad. A _ good preparation may be had by mixing _ together 14 Ib. of potassium hydroxide, _ I pt. of acetone, 14 pt. each of methylated _ Spirit, oil of turpentine, petroleum spirit _ spread over the paint surface and a few _ minutes later another application is made. _ This will soften the paint so that it can be _ removed with a scraper or spatula. _ Cleaning the Oil-Pump Screen on an Automobile Engine _ LSAULTY lubrication of an automobile _i engine may be traced to the clogging _ of the pump-screen by particles of dust and _ dirt from the incoming oil, with the result _ that a portion of the screen is defective and instead of allowing the oil to pass freely > > . ' into the pump-chamber it serves as a | barrier to its passage. For this reason _ the bearings receive an insufficient amount ' of oil and they become hot, causing the _ €ngine to lose power. It is necessary to _tTemove the pump-screen and wash it thoroughly. Experience will teach the _ Motorist that if this is done frequently, less _ trouble will result from improper lubrica- tion.—Apbo.ru KLEIN. . Popular Science Monthly and 5 oz. castor oil. A thin coat of this is 449 To Make a Triangle Gage for a Cross-Section Liner HE gaging of lines accurately for cross section work on a drawing requires some mechanical device. Lines cannot be drawn evenly spaced by dividing with a scale. The illustrations show the parts used in the construction of a cross-section Manner of placing the triangle and gage on the drawing board against the T-square liner which is used in connection with a T- square and triangle on a drawing board. An old wood T-square or triangle and gages cut from brass or aluminum (pref- erably aluminum) are the necessary parts. The binding posts taken from discarded dry battery cells will make good thumb nuts. Cut all the slides to fit the grooves as true as possible to avoid any side motion. Make all the parts according to the details in the illustration and glue them together as designated. To operate the liner place it on the edge 2 See TO GAGE - 2S a 55 Se —- = The parts made of an old T-square with metal gages of aluminum. These are glued together of the T-square as shown in the illustration. Adjust the gage A to the desired spacing distance on the scale and in the same man- ner adjust the gage B for a variable dis- tance. Start by placing the triangle tight 450 against the gage drawing line; then hold the frame firmly with one hand and with the other slide the angle to the right. Con- tinue this process by first moving the frame, then the triangle, for consecutive spacing. To make alternate spaces of a different width the slide C is used. To operate this slide place one finger on it and move the frame to the right until the gage is struck; then release the slide and it will be drawn back by the rubber band in the slot D. This operation is repeated as the lines are drawn.—R. B. Boyp. Making a Mahogany Case for a Grandfather’s Clock MOST appreciated piece of furniture is a grandfather’s clock; and to make one with your own hands adds much to its value. The design given is very appropri- ate, but it may be altered to suit particular needs and to fit a nook most suitable for it. The works forsuch a clock can be purchased at a nominal price. Any wood may be used in the construction of the case—mahogany or oak being preferable. For a clock about 7 ft. high, follow the dimensions as given in the illustration. The cross-section A-A shows how the waist sides and pilasters are joined and glued together. Another cross-section is shown at B-B. The lower front rail is fastened to ” \38 25 Dimensions of the clock case and cross- sections showing the manner of joining the sides with two dowels at each end and a screw is turned in between the dowels to draw the rail up to the pilaster. Popular Science Monthly The baseboard is molded on its upper edge and scalloped on the lower part. These pieces are fastened to the sides with glue and screws. To obtain a neat fit the front is first mitered and fastened in place, then the sides are fitted to the miter of the first piece. The bottom, which can be made of poplar, is screwed in place to help strengthen the base. A strip is temporarily fastened with screws across the top and on the inside of the pilasters to hold the sides together while the hood is being fastened in place. The hood-front is made up of two pieces, the outside stock being the same as that — used for the clock, and the inside of poplar. Miter the front piece and glue on the second. Miter and fit the hood-returns. Rabbet out the top and back edges for the top and back to set in. Lay off the circles and cut with a band saw to the line, and smooth with a sharp spoke shave. Care should be taken in clamping the hood-returns to the front not to draw them too hard on the clamp as the circle may be contracted and held there after the glue has hardened. Size all miter joints before gluing. The hood or arch molding is laid out on a piece of board 24 in. long, 8 in. wide and 14% in. thick. The mold is cut at a mill. Care should be taken to have every- thing square and all joints tight, as any imperfections will show up badly. All joints in the doors should be strongly mortised; but the tenons should not pass through the stiles. The arch rail should be cut at a mill. When gluing and clamping the door, place it on a level surface to avoid a twist and be sure that it is square. The door sets back from the pilasters 34 in. and three extra wide hinges should be used to swing it clear of the hood and pilasters. Rabbeted strips are fastened with screws on the inside of the pilasters for the door-stop. Two of these are fastened on the sides and one across the bottom. Two others on the sides extend from the center rail up, for the dial frame to rest against. The dial frame is for holding the dial. It should fit the hood and sides neatly. The joints should be strongly mortised. Thebackmay be made of poplar either paneled or in one piece. The finishing and staining are accom- plished the same as for any other home- made piece of furniture. It is always necessary to have a smooth surface on all the pieces for any kind of finish. ew ee ee Developing a Long Photographic Film in One Piece “HE device illustrated is useful in a _ developing kodak films. A long film may be developed and at the same time a sufficient portion of it can | be watched during de- ( _ velopment. Mount a film- holder of special shape on a base having suitable legs, together with a cen- tral rod and handle. Unwind a roll of film and remove the paper backing. S Wind the film _ around the upper part of the spiral sider, one end The long film is developed in the spirals of the holder flush ' top edge and secured, if need be, by other clips. After the developing the film can be readily lifted out and treated in other A Perfect Five-Pointed Star — Drawn with a Compass : TH a compass draw a circle. Divide ¥V its periphery into 5 equal parts, ___ stepping it off with a divider, and number the division points from 1 to 5. Draw a straight line from division point I to 3, from 2 to 4, 3 to 5, 4 to 1 and from 5 to 2. The result is a perfect star, the size of the star depending on the size of the circle. The Amount and Distribution of Water on a Farm FTER a pure water supply for the farm is made available, the things to ema tw oT vey v 4 con eee nal PT Pe. eee 6 a ed | a ne aM one he t i y = be considered are the quantity of water needed, choice of pumping equipment, and means of storage and distribution. The quantity required depends on the power used and whether the service is for the entire farm or for the house only. Hand- _ operated systems are applicable where small quantities are required for house service only; but in case water is wanted for stock, also, the use of a windmill, engine, electric motor or hydraulic ram is neces- If a windmill is used the storage should be large enough for at least three days’ supply, to provide water in case of calm weather Where the other sources of " a ay 2 Popular Science Monthly 451 power are used the storage capacity need not exceed one day’s supply. The following table gives approximate quantities of water required per day: Each member of the family for Aiiparnoeess= 245 So. ass 25 to 40 gallons Each cow will require. ....... a Each horse will require....... 10 Each hog will require.......- 23 Each sheep will require......-.. 2 The water consumption will vary from day to day and with the seasons. Fire protection should also be considered, and in determining the size of tank the maximum amount likely to be required should be provided. For a family of 6 persons a 200-gal. sup- ply should be sufficient if the water is used for the house only. On a farm where water is supplied to a family of 6 persons, Io horses, I2 cows, 25 hogs and 15 sheep, the daily storage supply should be at least 500 gal., exclusive of the amount provided for fire protection. Removing a Heavy Truck-Wheel Without a Chain-Block HE body of a motor truck usually overhangs to such an extent that it is impossible to use the chain-blocks for re- moving a heavy wheel. The method illustrated has been used with excellent results, and it requires the services of only one man. The wheel is jacked high enough to put a plate and rollers under it. The plate should be about 18 in. square. and 34 in. or more thick. The rollers are c 18" ROLLERS Plate with rollers beneath to make a movable platform for removing a heavy truck-wheel made of I-in. pipe 18 in. long. The car is lowered until the wheels rest on the plate and it can be easily pulled out on the rollers.—LESTER JONES. 452 Popular Science Monthly Keeping the Tobacco at the Top of the Can HE man who smokes a pipe and buys his tobacco in the “‘neat little tins’’ will save himself cut fingers and perhaps a degree of lost temper if he A movable auxiliary bottom to raise the tobacco in the can as it is used from the top will equip his tobacco can with an arrangement similar to that shown in the accompanying drawing. A groove is dented into one side of the can and a sliding strap of some fairly stiff metal inserted in the groove under a loop which is cut as shown. The strap is bent, half of it being inside the can. Whena little of the tobacco, which is contained in a snug fitting paraffined paper bag has been poured out the metal strap is pressed upward, bringing the level of the tobacco even with the top of the can. This can be repeated as the tobacco is used until the can is empty. Keeping Your Plants Watered While You Are Away F you are going away from home for a few days and are afraid your choice window plants may suffer for lack of water, place the plants around a large bucket filled with water, drop one end of a piece of yarn to the bottom of the water, and lay the other end on the earth around one plant, using as many pieces of yarn as you have plants. Sufficient inoisture will thus be carried to the soil to keep the plants in excellent condition for a long time.—H. C. FRANKE, JR. Using Dirty Waste Oil from Automobile Crankcases LD, dirty and worn out oil, drawn from automobile crankcases, drip- pans and other sources need not be thrown away. It can be mixed with coal dust and screenings and used for fuel. Use a pint or more with each hod of screenings, mixing well, so as to make a dry pasty mass that will barely hang together. useless products may be satisfactorily employed as a fuel—JoHN HOEcK. An Adjustable Shingling Jack for Sloping Roofs HIS jack-is arranged so it can be in- stantly fitted to any pitch roof by simply loosening the lock nut on sup- ports and raising the seat to the proper angle, then tightening the lock nut. The roof iron is made from 4 in. by 1 in. band iron and shaped like the sketch with the points sharpened to keep it from slipping in the roof. The hinges are cut from an old 4% in. by 4% in. door butt and notched out to receive the adjusting rods, which are made of 14-in. gas pipe which has been threaded up about 2 in. and split with a hack saw, as in the sketch. The button adjuster rod is of solid iron 44 in. in diameter and filed to slide into the 34-in. gas pipe. The MAY, 7 7 Tid (fC The supports have threaded adjustments like a turnbuckle to raise and lower the seat hinges are bolted on the seat and roof iron, and the measurements are from center to center. This jack was made with no other tools than a hack saw and a flat file. In this way two otherwise | =) J : and to do their best work they must be comfortably housed. The house shown in the illustrations is known as the “unit’’ squab house. For instance, if a man has but a few birds, pen No. 1 will be built. As soon as there has been saved a goodly number of youngsters from the best pairs, pen No: 2 will be constructed, and so on until there i exc birds deserve good homes, ‘have been built as many units as are deemed necessary. The size of each pen is 10 ft. long and 8 ft. wide with a 3-ft. passageway in the rear, which makes the total depth of the house 12 ft. In the construction the use of brick piers is recommended, as they will last a life time; but sound cedar posts 12 in. square may be used instead. If cedar posts are used their lower ends should be buried in the ground to a depth of 3 or 4 ft. Upon these piers are placed the 6-in. square sill. The joists are pieces 8 in. wide and 2 in. thick placed on the sills 24 in. apart between centers. As soon as the sills and joists are laid, the floor should be put down. The sub- floor should be laid diagonally, as in laying that of a house; then upon it is stretched a very fine mesh screen of galvanized poultry wire. This serves as an excellent protection against ro- dents. The top floor is laid upon this wire. Culled roofing boards or sheathing may be used for both floors, unless a better grade of lumber is preferred. The outside studs are all 8 ft. long and by ordering them in 16-ft. lengths Modern Squabhouse Construction Ze ity ae by F- Arthur Hazard so there will be less waste of material. The rafters are all cut from 8-ft. pieces. The plates are studs laid double. Another stud is placed on the floor under the ends of the outside studs to give a better bearing surface. The studs and rafters are both placed 24 ins. on centers. The roof is first covered with culled boards placed diagonally on the rafters; then these are covered with a. good grade of prepared roofing. It is not best to put on an inferior grade, such as three-ply tar paper, as this will only last 8 or 10 months. No part of the building will need repairing as often as the roof. Thin beveled siding is recom- mended for ease in working and the neat appearance of the finished job. Sheathing should be placed on the studs on the inside. If a good, warm house is desired, place sheathing under the siding also and fill the space between them and the plates with cinders. The windows are stock sizes, which are not very expensive. These are hinged at the top on the inside and they swing up and in. By means of cords and pulleys they can be operated very easily from the passageway. This elimi- nates having to go into the pen on cold nights to shut down the windows, and possibly scaring the birds. In each gable is placed a louvre ventilator, the back of which is covered with No. I wire mesh to keep out sparrows and other small birds. These louvres will ventilate the building at all times. The nests shown are double, each 453 454 Popular Science Monthly i 1 : PREPARED ROOFING ! | l ———— 1 F LF ay 7 a = BER 4 es Ne —_—_ zs hy i at aay re, os : GRADE Elevation of the house showing the construction and location of the brick piers beneath the ends of the partitions between each of the pens where they support the ends of the sills pair having two nests adjoining. Be- tween each pair of double nests there is an upright. This keeps the cock birds from fighting. A glance at the plan and then at the section will show the good features of the double nests. In placing the nests as shown there is no draft across any nest box—a decided ad- vantage. This pen with its arrangement of nests will easily accommodate 50 pairs of breeders. be placed a crate containing plenty of nesting material. necessity and must not be overlooked. Beneath the house and at the back of the fly is placed a frame made of 2-in. square material on which is stretched a 2-in. wire mesh. These frames fit in — between the brick piers. The fly pens are constructed of studs, which form the uprights. Around the base of the pens is placed a board 8 in. Under the bottom row of nests should wide. The tops of the uprights are a | tT) ; -6'x 6-6°x 13/6" ——S Paper strips placed under edge of spring-sup- ports to secure fine adjustment of the tension for the coil to deliver sparks of maximum power. The wear may be taken up by the screw but this will cause a weak tension on the spring. To overcome this difficulty on the coil I owned, pieces of paper were placed under the spring-support as shown in the illus- tration. This made it possible to obtain a finer adjustment with the thumbscrew, and eliminated the trouble —Joun U. LEVERSEE. A Concealed Rheostat for Audion Cabinets N audion cabinets a rheostat is gen- erally used for controlling the low- voltage battery current. The cabinet looks much neater if the rheostat proper is con- cealed and only a control-handle and pointer can be seen. Such a rheostat mav be constructed as follows: Procure a porcelain-base battery rheostat and remove the stiff brass contact-arm and the center bolt. Make a contact-arm from light spring-brass and slip it on a long battery- bolt; lock it in place by means of a flat battery-nut, place on a washer and then 46 Electrician : PAnd Wireless Operator Amateur - ——— _-——$$__—_——_—— insert the bolt in the hole in the center of the rheostat. Place another washer over the bolt, on the back side. The connection with the binding post should be soldered to this washer. Screw on two more flat battery-nuts, adjusting them so that the arm will slide evenly and smoothly over the resistance element, and then lock the nuts by screwing them against each other. Next secure a brass rod 4 in. in diameter and sufficiently long to project 1 in. from the front of the cabinet when the rheostat is placed against the back of the panel. Such a shaft may be found in some old telephone ringers. Drill a hole in one end of the brass rod and thread the hole to fit the bolt in the center of the rheostat base. Turn the other end down a little in a lathe and thread it so that it will take a battery- nut. Screw a nut on to the bolt on the rheostat and then screw this bolt into the hole in the end of the shaft, locking it by screwing back the nuts. Drill a hole in the panel of the cabinet and insert in this a bushing from an ordinary incandescent- light socket. Insert the shaft and screw the rheostat to the back side of the panel. Make a pointer of brass, about 114 in. long and slip it over the small threaded end of PORCELAIN “RESISTANCE “ N The rheostat is on the back side of the panel and is operated from the knob in the front the shaft. Make a handle by cutting a piece of hard rubber, or fiber, 14-in. thick, in the form of a circle 114 in. in diameter, drill a hole in the center, and place it on the shaft over the pointer—FRANK SAHLMAN, ‘ 468 Popular Science Monthly Scale for Inductive Coupler for Making Log-Book ROCURE a wooden ruler and cut it the proper size to fit between the front end of the primary and the support for the secondary rods. Fasten it so that the coupler secondary will clear it, and attach a small pointer to the sec- ondary coil end. This will serve as a guide when tuning for distant stations RULER An ordinary ruler fastened between pri- mary coil end and support for a scale and is also very handy in making out a log-book. Once you have used a scale - to mark the coupling of your receiver you will always want one. Select an ordinary ruler such as found in school outfits, which has graduations no less than 8 to the inch—16 will be much better—SAMUEL HUFF, Heated Wire Is Telephone Transmitter T is an interesting fact not generally known that an exceedingly fine wire, red hot, will, under suitable conditions, serve as a telephone transmitter. Sound waves striking the wire vary its resist- ance to such an extent that the variations are plainly noticeable in a sensitive tele- phone receiver. A Russian inventor has_ recently brought out an improved type of ‘‘ther- mo-telephone,’. ’ as it is called, in which Wire embedded in block of suitable insu- lating material and used for a transmitter the heated wire is almost entirely en- closed in a protective body. His inven- tion includes a number of ways of em- . bedding the wire. In one case, it is cast in a block of suitable insulating material. In others, it is merely held tightly be- tween the surfaces of close-fitting hinged plates. In use, the ends of the heated wire— which is usually Wollaston or very fine platinum—are connected through a bat- tery to the receiver. Sound waves strik- ing the block increase or decrease the resistance of the wire, allowing more or less current to flow through, with a con- sequent variation of the sound being emitted by the receiver. Device for Testing Spark-Plugs Without Removing Them ESIGNED to enable spark-plugs to be tested without unscrewing them from the cylinder, the simple device shown in the accompanying views con- sists of a T-shaped handle of non- wt FIGL | _ ieee | : ZINC r WIRE\ t tO-—O- Fy | a | An insulated handle for making spark gap on an engine plug without unscrewing it conducting fiber to which are attached two pieces of zinc wire of unequal length. The wires are bent as shown and are held in place on the fiber handle by means of two binding posts, the ends of the wires between the posts being about the thickness of a dime apart. In operation, the main spark-plug wire is kept in place to furnish current to the plug and the short wire of the de- vice placed on the top of the plug electrode and to the long arm on the cylinder. Then as the motor is turned over, a spark will jump the gap between the ends of the zinc wires if the plug is in good condition. If short-circuited, no spark can be secured. If the por- celain is defective the spark will be weak and irregular. How to Make an Electric Heater One of three hundred and twenty-six watts capacity is easily constructed By Roland Jens slightly more expensive to operate than a wood or coal stove, is ideal for a bedroom, or rooms that are not re- quired to be heated at all times. The - heated air from an electric heater is as pure as the air in the room in which it is placed, while if the same room is heated with a coal stove, poisonous gases es- cape. Details are shown A aieniis electric heater, although ~ The next step is the rolling and rivet- ing of the sheet iron plates. If a roller for rolling sheet iron is at hand this part becomes easy, but if it is not, other means will have to be resorted to. One alternative is to bend the plates over a round wooden cylinder or. gas pipe which is of about the same diame- ter as the cylinder. As the metal is thin, it can be easily bent in this way with rea- sonable accuracy. After the sheets have been bent, rivet the upper five holes “x: with \-in. soft iron rivets in Fig. 1. The work may be divided into the follow- ing parts: (1) Construction of cyl- inders. (2) Construction of legs or base. (3) Winding of cylinders. (4) Construction of cover te. (5) Assembly. (6) Connections. First the sheet iron plates are to be cut. Sheet iron of pty fp 1/32 in. thickness should ft > dd db be used, but if this cannot. BeGiiained, plates slightly thicker or thinner will do. Cut the plate for the 12-in. cylinder (Fig. 6). In order to make the corners exactly 90°, lay off a base line on — 3/16 in. long. The lower hole is not riveted at this time because the cylinder is fastened to the base by means of this rivet. If the cylinders are not quite round, due to improper bending, they may be rounded off by placing them on a fairly large piece of gas pipe and pounding them into shape with a maul. 17° The legs or stand of the heater are made of two strips of sheet iron 1 in. thick, I in. wide and 17 in. long. (Fig. 11). Center- punch the middle of each ss ee a he ees Fame Lj the plate from which you are to cut and with a car- penter’s square lay off on the base line two right an- gles 3834 in. apart. Lay off 18 in. on the two piece and lay off the 44-in. holes, as shown in the draw- ing. Drill the holes and file off the burrs caused by drilling. To bend the ends into the shape shown, grip lines which form a. right the strip and a %4-in. bolt _— angle with the base line. Connect the two points by a straight line, and you will have a rectangular plate. The Y%-in. holes are now drilled or punched. Drilling is preferable as it gives a better and more accurate hole than punching. After the plate for the 12-in. cylinder is done the plates for the other four cylinders are laid out and drilled in the same manner. Fig. 1. Top, eleva- tion and base plan of electric heater in a vise and pound the metal until it closes around the bolt the desired dist- ance. Remove the bolt and strip. Turn the strip around, tighten in the vise again with the bolt and pound with a hammer to get the second curva- ture. Do this to each end and then rivet the two together with a %-in. rivet through the center hole. The next parts to be made are the 34 469 470 Popular Science Monthly x + Ol. 4 4 > 6 SHEE Iron pe Tor 6'cylinaer|' fe SEES Wor pave for- J Zz” a les 6cylinder Tv al 19. 5 fig. 9 ai ~- : +@- -e 2 © aa -O- Qe 7) -o » 25 7 © | - +e & rid be Yes! tl! ¥ Pa ted Z id . S w+ fi oS ae y BS d a y “4 > ? . 1 6 sheet iron plate for 12" cylinder ¢ holes T Td sheet iran plate ~ 1 f/g.0 ey eee i eee: + : 58} oe : -o- Sf. oH ae ae a is -@- oH % fig. 10. ” 4 ; v7 a” “ “0 T g i CS Bid A ee a El es ? t SY ay Bx i a . : , f % 4 The cylinders are now b @ sheer iron plore ror 10° cylinder ready for winding. The zs! “holes a4 method of winding is shown ° Fg.7 in Fig. 12. Wrap sheet a jaf ‘) | asbestos 1% in. thick around 7 ® the cylinders and then start Ai ms to wind at the bottom. ee se Wind the turns about \% in. 2 ae ° Sars ‘ “ htly against the zea las 7Z z ¥ apart tightly ag é ie SO ERS J } “i , 78 {2 | asbestos covering. At the ¥ | i) | top make a similar fastening Patterns for laying out and marking the drill holes for making the cylinders to hold the heating elements in. by 2 in. angles by which the cylinders are fastened to the base. (Fig. 8). These angles are made of sheet iron strips 1/16 in. thick and I in. wide. Cut twenty pieces of this size sheet iron strips 234 in. long and bend them as indicated in the drawing. A good way to do this is to clamp the piece in a vise so that 2 in. pro- . trude above the grips, and . pound this part over with a : hammer until a right angle is formed. The two \%-in. : holes can then be drilled as indicated. The next operation is to rivet the angles on the bottom of the cylinders. The angles are riveted on the inside of the cylinder the long side against the side of the cylinder. Cylinder base clips to the one at the bottom. ~ To make the fastening per- manent solder the junction. No windings are placed on the 12-in. cylinder, as it is used to protect the windings on the other cylinders. One pound of No. 25 B. & S. gage bare copper wire will be required. The next part to be made is the cover plate. A detail drawing is shown of it in Figure 1. This plate is made of sheet iron. After all parts are finished and the cylinders wound the parts are assembled. Place the 12-in. cylinder in position and rivet it to the base by means of 44-in. rivets, connecting the angles ‘and the base. After this is in place fasten the 10-in. cylinder in the same way, then the 8-in., 6-in. and 4-in. The next operation is the making of proper connections. The lower end of ‘7 Popular Science Monthly wire of the 10-in. cylinder is connected to -one of the terminals. The top end of wire of the 10-in. cylinder 471 ionized gas collects between the sparking points, the breakdown voltage of the gap will be reduced and is connected to the lower Toe sparks will pass premature- end of wire on the 8-in. ly. The same unfortunate cylinder, the connection ieee result ‘occurs when the being made at the bottom. eee es electrodes become over- Enough wire has to be left heated and tend to produce at the top of all cylinders sae arcs. The effect of such so that this connection can tt 7 irregular sparking is to re- be made. Care must be [iii]! duce efficiency and to make taken that the wire does fii/ffF44-}_t | production of a clear signal- not come in contact with TT tone impossible. any metal at any point. In The drawing shows a the same way connect the | tb form of spark-gap devised windings of the 8-in. and ee by H. Shoemaker and dis- 6-in. and of the 6-in. and [ij closed in U. S. Patent 4-in. cylinders. The top Witnen eel 1,170,853 for 1916. The end of the wire on the “TTY usual alternating-current 4-in. cylinder is brought transmitting circuits are out to the other terminal. used, in which power from The two terminals may be al the generator 20 is led placed near the bottom of through key 21 to step-up the 12-in. cylinder. Drill a joopis made for starting transformer 22-23. The through two )4-in. holes and insulate two terminal posts in these holes and tighten them. The wires from the heater leading to the terminals can be connected on the inside and from the outside the socket. .connec- tions can be made. The terminals from the positive pole of ordinary dry bat- ‘s oe Ses lick aaa Pattern for cutting and drilling the legs or stand pieces that hold the cylinders teries can be used. Drill the two 4%-in. holes about 2 in. apart at any convenient place near the bottom. Insulate the terminals with hard rubber or fiber. After this is done place on the cover plate and the heater is ready for use. New Patent on _ Interrupter Spark-Gap » et eed spark-gap, or one upon 4 which a cooling air-blast is blown, is generally more regular in operation than a simple open stationary-electrode device. To secure uniform sparking, the condition of the gap and the electrodes must remain constantly the same. If wire and coil on cylinder secondary charges condens- er 13, which oscillates through primary 12 with variable top 15 and spark-gap 9, Io. The antenna 16 and ground 19 are coupled through secondary 17. The novel feature of this transmitter is that between the stationary gap electrodes 9, 10 is inserted a rotary disk of mica, glass, porcelain or some other such insulator, pivoted on shaft 3 and supported in bearings I, 2 as shown. At equal distances around the disk, and a few inches from the outer edge, are drilled a series of holes such as indicated at part 7. These holes pass in front of the spark-gap electrodes, and sparks can pass only when a hole is directly between 9, 10. Thus, by rotating the drilled insulating disk the effect of a rotary A mica disk with holes is rotated between the gap electrodes, assuring an even spark spark-gap may be had without any difficulties of insulating moving parts. The disk may be driven by an electric motor. The patent suggests making it a sort of air-driven turbine. 472 Popular Science Monthly Making a Practical Fluoroscope at Home ANY electrical experimenters pos- sess apparatus such as Tesla, or high frequency apparatus, a large spark-coil, or a static machine, which may be used very well for X-ray ex- periments with only a few accessories. The high cost of the most important of these accessories, the X-ray tube and the fluoroscope, has caused many amateurs to defer, not without reluct- ance, work in this most interesting and instructive field. It is impossible to make an X-ray tube in the ordi- experimenter is calcium tungstate. This is sometimes found in a_ sufficiently pure state for use in the natural mineral scheelite, or it may be purchased from a reliable chemist, or made in the lab- oratory. Great care should be taken in order to secure a good crystalline variety. In order to prepare calcium tung- state (CaWOQ,), in the laboratory, 294 parts, by weight, of sodium tungstate, - (Naz WO,); 111 parts-of calcium chlor- ide, (CaCl,); and 59 parts of common salt, sodium chloride, (NaCl) are thor- oughly mixed. The commercial, chem- ically pure sodium x nary shop or labo- ratory, but it may now be purchased at a very reason- T able price. In or- oa der to secure the | best results, care should be taken to select a tube designed especial- ly for use with the particular type of apparatus to be used. There is considerable dif- ference in the de- FIG. tungstate should first be pulverized and heated in an air bath to about 110° C, or 225755, until the water of SCREEN been driven off, te" ‘and the salt is thoroughly dry. m7 The calcium chlor- z ide and salt should also be pulverized ~ and dried at about the same tempera- ture. This should sign of tubes for oR be done before J weighing th the different types of apparatus. A Sa Se 3 oS chemicals. . tube made for use upon a static ma- chine may give very poor results upon a coil or for other purposes, and last only a short time. It is best to get a tube with some form of vacuum-regulating device, as it great- ly increases its usefulness and life. A fluorescent screen or fluoroscope may be constructed in the laboratory, and may. be used equally well with any form of apparatus or tube. To make the fluorescent screen, the fluorescent substance is mounted upon any suit- able supporting surface, such as card- board, in an even continuous layer, so that the rays act through the support and excite the active substance. A great deal of experimenting has been done in order to ascertain just what substances are fluorescent, and which possess this property in the highest degree. Perhaps the substance best suited for the use of the average Frame and pyramid for cutting out the side lights from the The mixture is placed in a cruci- ble and heated in a furnace or with a blast lamp until it is thoroughly fused. ‘The crucible is then very gradually cooled, and when cold, the mass is extracted by dissolving out the sodium chloride with water, which leaves a mass of calcium tungstate crystals. These are separated from the liquid by. filtering, washed well with water to remove any trace of the chloride, and thoroughly dried. These crystals should be sifted through a sieve with a mesh of about 30 to the linear inch, and preserved for use in a well stoppered bottle. Another method of preparing this salt is to precipitate the calcium tung- state from a solution of sodium tung- state in water, with calcium chloride or nitrate. The precipitate is removed by filtering, thoroughly washed, dried and mixed with about twice its fluorescent screen a a) a ee crystallization has ~ Popular Science Monthly bulk of borax (sodium tetraborate, Na, B, O,). This mixture is placed in a crucible, fused thoroughly, cooled very gradually, and, when cold, dissolved | out of the crucible with water. Great care should be taken to obtain the salt in as ‘perfect a crystalline form as pos- - sible, for its fluorescence appears to be very much dependent upon this. A piece of good grade, smooth, light- weight cardboard, 12 in. long by 9 in. wide, is covered with a layer of glue, made by dissolving gum arabic in water. Care should be taken to have the glue in a very even layer. The calcium tungstate is sifted onto this from a sieve in as even a layer as possible, not too thickly, yet covering all parts well. This is called the fluorescent Screen. A light, square frame, as shown in Fig. 1, of the same size, 9 in: by 12 in., should be made from soft wood about ¥ in. wide by 3% in. thick. The fluores- cent screen should be tacked or glued to the one side of this frame, with the coated side next to the wood, as shown. Another frame, as shown in Fig. 2, shaped like the frustum of a pyramid the lower base of which is 9 in. by 12 in. (the same size as the frame supporting the fluorescent screen), the upper base 3 in. by 6 in., and the altitude 12 in., is made from wood % in. wide by % in. thick. The sides of the frame should be covered with black velvet or other dark colored cloth, so that it will entirely cut off the outside light. This covering should extend about 2 in. or 3 in. over the small end of the frame, so as to form a curtain about the face when looking into the frame. This frame serves to cut off the outside light when looking at the fluorescent screen, and may be pro- vided with a handle to facilitate han- dling. It should be provided with flat springs or hooks, as shown in Fig. 3, on the larger end, so as to hold the smaller frame supporting the screen in place. The coated side of the screen is placed inside. _ In case it is desired to experiment further, a number of substances will be found which fluoresce under the action of the X-rays. Most of the phosphides of the alkaline earths and the salts of manganese, cadmium, strontium and lithium, are active. Liquids are gener- ally inactive, and it is notéd that whilé 473 quinine sulphate give a bluish glow, a solution of this sulphate is only very slightly excited. Thomas A. Edison experimented with some 1,800 phosphorescent and fluores- cent substances, some of which are here given: Ammonium platinocyanide, am- monium salicylate, barium sulphate, boracic acid, cadmic iodide, calcium fluoride, calcium platinocyanide, cal- cium sulphate, calcium sulphide, corun- dum, curcumin, caturine, glass, mica, mercurous chloride, obsidian, penta- decyltolyl-ketone, potassium acetate, potassium iodide, potassium bromide, potassium platinocyanide, quinine salts, rock salt, strontium platinocyanide, strontium sulphate, strontium sulphide, strontium tungstate, uranium fluoride, and uranium sulphate. A few of these substances are active under the rays of a Geissler tube. The substances most used on com- mercial fluoroscopes are calcium . tung- state and barium platinocyanide. Ura- nium ammonia-fluoride gives good re- sults also. Some experimenters claim better results with barium platinocy- anide than with calcium tungstate, but this depends somewhat upon the crys- talline condition of the salts. How- ever, the high cost of barium platino- cyanide more than offsets this possible advantage with the average amateur experimenter. In mounting barium platinocyanide, uranium ammonio-flu- oride or substances soluble in water on the screen, a solution of celluloid in amyl acetate should be used, so as not to injure the crystalline form of the active material—CHARLES E. MILLER. Cutting Holes in Plaster for Switch-Boxes UTTING a hole in plaster for the purpose of locating an electric switch-box is a difficult and untidy task and especially where this is to be done on a completed house. The job can be accomplished quickly and neatly if a box is used for the cutting. A box of the proper size, set with its edges to the plaster and driven on the bottom, will cut a neat square or rectangular hole without much effort. Begin by driving on one corner and follow along one side and then around the box. The edge will cut the plaster through and the particles loosened will fall into the box. A474 Increasing the Frequency in Radio-Telegraphy HE simplest way to set up currents of very high frequency in a _ wireless telegraph antenna is to connect a special radio-frequency alternator in series with it and the ground. If this special dynamo generates current of 100,000 cycles per second, and if the antenna system is tuned to this frequency, intense waves of 3,000 meter wavelength will be radiated. It is a very difficult mechanical problem to design, build and operate alternating current dynamos of large power at such high frequencies as 100,000 per second. Such machines are in use, however, giving out- puts of some five kilowatts, and it is be- lieved that much. larger generators of the same sort can be An unusually ited. method for greatly mul- tiplying the normal fre- quency of an alternator built. But it is much easier to make dynamos of lower frequen- cy. Ifa 33,300 cycle generator is connected to an apparatus which triples the current frequen- cy, it is evident that the output terminals of this frequency transformer could be led to an antenna circuit and that the system would set up, in the antenna, currents of 100,000 cycles per second fre- quency. By usinga large alternating current dynamo of one-third the frequency its con- struction is greatly simplified; and as a re- sultof this fact, inventors havefor some time striven to produce efficient frequency trans- formers to be used in radio transmitters. United States patent number 1,174,493, recently issued to E. F. W. Alexanderson, shows how a mercury-vapor tube may be used to distort the wave-form of a high frequency alternator and how the aug- mented harmonics may be picked out and used to excite antennas for wireless. The figure is taken from the patent, and in it A represents the high~ frequency machine which supplies power to the system. Con- nected across its terminals is the mercury- vapor bulb B, which may consist of a vessel having two pools of mercury at its bottom and a third electrode at the top, as shown. An electric arc passing between the pools and fed with.current from the auxiliary circuit C, comprising a- battery and resistance, serves to start the vacuum ia || ae _ Popular Science Monthly tube; current from the dynamo A keeps it in operation thereafter. The effect of using such a vapor lamp as a load for the alternator is to emphasize the third and even the higher odd harmonics in the fundamental current; that is to say, when the lamp is lighted the generator is caused to amplify one of these harmonics which are always part of the entire current it gives out. Each of these component currents in an ordinary generator is a direct odd multiple of the original fre- quency, so that if the dynamo is built to generate 30,000 cycles, the generator-and- lamp systém will produce principally cur- rents of 90,000 cycles, or even higher frequencies. Series circuits containing capacity and inductance, such as D, E, and H, may be connected across the line wires and “‘tuned’”’ to the high- harmonic frequencies. When this is done, comparatively large currents of the tuned frequency will be produced in each condenser and coil. A transformer pri- mary, such as H, being part of the same circuit, is coupled to an antenna and ground system, as indicated at J. If the antenna is also tuned to the har- monic frequency, it will have set up in it — currents of that frequency and will radiate corresponding waves. Thus a compara- tively low-frequency dynamo may be used to generate very short waves by this process of frequency transformation. If the fundamental frequency is 25,000 per second, the wavelength produced directly would be 12,000 meters; by tuning the circuit D, E, H to the third harmonic, and adjusting the antenna to correspond, waves only 4,000 meters long are sent out. Specially constructed alternators giving unsymmetrical currents are now being used with this system of amplification also. Only unsymmetrical waves may contain the even harmonics, so that the system can be used with such an alternator simply to emphasize the second harmonic, thereby doubling the frequency. An Emergency Aerial Using Door- Bell Wires. AVING some difficulty in getting an aerial erected, I tried using one side of the wires connected with the door-bell. With this indoor antenna I am obtaining very good results in receiving. It is only necessary to disconnect one of the bell wires and attach a wire to lead to connec- tion on the tuner.—RIcHARD A. LIDDANE. - ee ee oe ata ab igh ‘ baile aa! How to Become a Wireless Operator VII.—The Variable Condenser for Tuning the Secondary By T. M. Lewis HE direct coupled receiving tuner which was described in detail last month will prove satisfactory for long distance working, up to the limit fixed by the sensitiveness of the detector and tele- phones used in connection with it. The loudness of signals, if the coils and switches are properly built, should compare very favorably with the best obtainable by using an inductively coupled receiving trans- former of equivalent design. To get the strongest signals, in either the direct or the inductively coupled outfit, the operator must determine by trial the best settings of primary and secondary. inductance and coupling, as previously pointed out. Sharpness of Tuning Although the simple tuners without variable condenser in the secondary will & _ give loud signals, and in fact about as loud as can be obtained by any arrangement of tuning circuits when working with spark stations, the best sharpness of tuning can- not be secured. When two transmitters are heard at about the same intensity and on only slightly different wavelengths, it is difficult to build up the signals of either at > _ will by the mere adjustment of the coupling and primary and secondary inductances, when the circuit without variable condenser is used. For this reason the tuner, whether _ inductively or conductively coupled, which has the detector directly in series with the blocking condenser (7. e., which has no condenser directly across the secondary terminals for tuning) is called ‘‘broad tuned.”” However, if a variable condenser is connected as shown in Fig. 1 and 2, the selective powers of the circuit become very much greater and it is called ‘‘sharp tuned.” The details of adjustment which are necessary in order to get the best results from the sharply tuned receiver will be taken up in full next month. The manipu- lation of this receiver should be second nature to all radio operators, since it is the arrangement of apparatus used by the great commercial companies. In the hands of an unskilled operator better results are some- times obtained with simpler circuit ar- rangements; the reason for this is simply that the man does not know how to get the most out of the sharply tuned lay-out. The circuits of Fig. 1 and 2, when correctly adjusted, provide the maximum selective- ness which is to be had in the best commer- cial receivers in general use. Securing the correct adjustment, once the principles are clearly understood, is merely a matter of practice. It is essential for the student, therefore, to familiarize himself with the actions of such receivers under all condi- tions likely to be encountered in practice. The Variable Condenser Since Fig. I is exactly the same as Fig. 7 of last month’s article, except for the addi- tion of the variable condenser and a single sarvtiniih pole switch for cutting it out WV of circuit, all of the instru- toaping ments described in the pre- COL VAR COND. 4 (a. DETECTOR COND ge i FIG. 1 =6 PHONES Diagram for direct coupled receiver with variable condenser and a single pole switch ceding articles of this series may be utilized. The switch of Fig. 1 is preferably a small single pole, single throw knife- switch, since this type almost invariably gives good contact, though any other form will be satisfactory if kept in good condi- tion. The variable condenser. is the im- portant new instrument, and must be of good design if it is to be really. useful. The amateur who has sufficient funds at his dis- posal will do well to buy one of the standard variable condensers now on the market; if he sticks to the ordinary semi-circular rotary type, having a capacity of about .0oI microfarad and costing from $5.00 to $25.00, he will be likely to get a good in- strument for tuning. The cheapest ap- paratus, as well as the various freak forms 475 476 which appear from time to time, are less likely to be satisfactory. Since good variable condensers are ex- pensive, as compared with the other parts of short-wave receiving apparatus, a simple and yet good design for making them at ANTENNA \V : DETECTOR D VAR, ‘ a COND, PHONES PRIM. SEG. — B = su.\y cond. | G FIG.2 Diagram for inductively coupled receiver with variable condenser and single pole switch home will be described. The condenser made in this manner will prove rugged and suitable for continuous operation, will have good insulation between its terminals, and yet will be found easy and comparatively quick to build. The Fixed and Moving Plates The plates of the condenser may be made of almost any conducting material. Alum- inum about 1/32 in. in thickness is by far the best, since it is light, soft and easily kept flat. Soft brass or copper will prove suitable though heavy, and even sheet tin can be used if reducing the expense is of the greatest importance. The fixed plates are laid out as shown in Fig. 3. They con- sist merely of rectangles 2 by 5 in. in size. About 3% in. from each corner, on a 45 deg. line a hole is drilled to take the support- ing uprights. The relation of the plates to a semi-circle of 2 in. radius, which corre- sponds to the active surface of the moving plates, is also shown in Fig. 3. The rectan- gular form of plate is shown for the reason that it is the quickest and easiest to cut out. Obviously, if material is of more importance than time, the corners may be cut off and the outer side of the plate held by a single vertical bolt passing through suitably placed holes at or near the center of the upper edge. _ The form of the moving plates is shown in Fig. 4. Essentially, these are portions of circles having a 2-in. radius; they are roughly semi-circular in form, and the exact relation to a half-circle is shown by the dotted lines. A hole to take a 5/32-in. Popular Science Monthly bolt is drilled at the central point where the radii meet, as shown. This design of plate is about the easiest to make of all that have been suggested, and yet is not particularly wasteful of material. For the tuning condenser, 13 fixed and 12 movable plates may be cut out. The sim- plest way is to make a full size templet or pattern out of pressboard, and to scratch the outline of each plate on the material by running a needle around the edge of the pattern when held tightly on the surface of the metal sheet. trimmed ‘out with sharp shears, clamped together in a vise and filed to exactly the same size and shape. They must be flattened by hammering, preferably be- tween perfectly flat metal surfaces, until no dents or warping can be seen when the plate is held edgewise to the eye. . , The Top and Base Hard rubber or horn fiber, from 14 to %% in. in thickness is the best material for the top and base. If these cannot be used, hard- wood about 1% in. thick will do. In the illustration, Fig. 5, are shown the two pieces that form a 5-in. square, and how they are drilled at each corner, in the center, and at the inner corners of the fixed plates, to take the several bolts. The base must also be drilled and tapped near the center, to take the foot or base bearing of the vertical shaft, to be described later. In Fig. 5 there are shown the outlines of both the fixed and moving plates in their proper relative posi- tions, so that no difficulty should be ex- perienced in laying out the holes once the plates have been finished. Other Materials Practically nothing else is needed except. a number of 8-32-hexagon brass nuts i -_— Oo] fF ° i a. oO}. aye Be an io fe ol of Cc ma at) ~ & a pease SF SS ee eee Enea | _?-— FIG.3 F1G.4 The form of the plates are ares = |—__ ss —_4] of circles having a 2-in. radius FIG.S (machine screw size No. 8 with 32 threads per inch), a considerable quantity of copper’ washers or burrs which will slip freely (but not too loosely) over an 8-32-machine screw,: six threaded brass rods of 8-32 size and. about 5 in. long (the excess is cut off after assembly), a 5 in. by 5/32 in. threaded The plates are then ees ae es ee a of the insulating base. _ washer, the base itself is placed on, and _ then a threaded rubber, wood or fiber foot Popular Science Monthly brass rod with 6 hexagon brass nuts to fit, a number of perfectly flat brass or copper washers of about 5 in. outside diameter, which will slip over the 5/32-in. bolt, a little soft brass strip, two small screws and a hand wheel. of the 8-32 bolts is used to support the top of each corner of the group of fixed plates in proper relation to the top of the con- _ denser itself. As indicated, the completed _ assembly begins at the top with a hexagon - mut and washer, after which comes the _ §-in. square top plate. This is clamped in place by means of a second washer and nut, after which come separating washers to _ space the uppermost fixed plate the proper _ distance from the lower side of the insulat- _ ing top, and then that plate itself. After _ the first plate, enough washers to make a _ space of 14 in. are put on the threaded rod, _ and then the next plate. Thus the thirteen fixed plates are placed on and clamped by _ the nuts of four of the threaded rods. At _ the bottom, as shown in Fig. 7, the third qi - nut is screwed upward to hold the plates _ firmly, and a fourth nut turned on to the point which will hold the lowest fixed plate the correct distance from the upper side After adding a is screwed on to clamp it all in place. Of _ course, only the corner posts of the base _ itself take these feet; the two rods at the _ inner edges of the fixed plates are fastened __ by screws and washers on the lower side _ of the base. The two corners of the base, shown at the lower part of Fig. 5, where no fixed plates reach, are supported by the fifth and sixth threaded 8-32-rods in the manner shown in Fig. 6 and 7, with the obvious exception that the plates themselves and their separating washers are omitted. The Rotary Part _____ The moving plates are assembled upon _ the 5/32-in. threaded rod, clamped by the _ hexagon nuts and separated by the larger washers, as shown in Fig. 8 and 9. Begin- ning at the top of Fig. 8, it is seen that the hand-wheel, which may be a knurled disk _ of Y%-in. hard rubber 2 in. in diameter, is _ clamped at the top of the 5/32-in. rod or _ shaft between two washers and nuts. Be- _ tween the lower nut and washer there is copped the end of a bent metal indicator- d which points to a degree scale (a cheap protractor makes’ a good one) In Fig. 6 is shown how one | 477. mounted on the upper side of the insulating top. Just below this lower nut is a little brass bushing or tube, forced into the in- sulating top and having the right inside diameter to act as a bearing for the shaft. Below this come separating washers—one or more—and then two nuts which lock each other and hold the moving plates in-place. The uppermost moving or semi-circular plate comes next; immediately below it, and separating it from the next plate, are enough of the larger washers to space the plates just 14 in. apart. As shown in Fig. 9, the moving section is built downward, and the lowest plate is clamped in place by two more nuts. The shaft itself continues for about % in. farther, and is tapered off to a blunt point so as to reduce friction. The Lower Bearing In Fig. 9 is also shown how two pieces of 1/16-in. soft brass strip are bent and , i, DIA FIG.9 The machine screw fastening at the upper and lower corners and the main shaft bearings drilled to form a thrust bearing for the lower end of the shaft. They are secured to the base or lower 5-in. square insulating plate by the two machine screws. Elec- trical connection is made to the moving plates by soldering a wire to one of these screws, running it out to one of the corner screws which is not associated with the fixed plates, and once more soldering it there. A binding post takes the place of the top nut of Fig. 6 on this outside screw. Similarly, a second binding post substi- tuted for the uppermost nut on one of the screws supporting the fixed plates provides a convenient means of connection with the fixed plates. For continued service it will not do to 478 depend upon the electrical contact in the bearing of Fig. 9 alone; a small piece of thin spring wire (brass or phosphor bronze) should have one end soldered to the shaft just above the upper plate of the base bearing, its other end being fastened to the - bearing itself after one or two spiral turns are made loosely about the shaft. This will prevent any possible trouble from oxidation of the contacts within the condenser. A stop should be provided to keep the plates from turning more than 180 deg. and twisting off the spring wire. Assembling and Adjusting Manifestly the foregoing descriptions, with reference to Fig. 6, 7, 8 and 9, apply to the completed apparatus. The best way to assemble the instrument is to clamp to- gethér the fixed plates on their four rods, independent of either the base or top plates of insulating material. When the conduct- ing plates are all set parallel and with the - , proper 14-in. spacing, they are laid aside and the moving plates similarly assembled upon the shaft. The base, hand wheel and top are left apart until the moving plates have been correctly spaced and adjusted. Then the moving plates are slipped interleaf- wise between the fixed plates, and the insu- lating top put in place. By trial the proper number of washers and the best position of the clamping nuts is determined, and the top is then fastened. Next the base is ad- justed to the proper position, and all the fastening nuts tightened. Last of all the hand-wheel and pointer are added, and the scale set to the correct position. It is a good plan to cut a strip of celluloid film to just the width of the space between the insulating top and base, and to bend it around the metal parts so as to exclude dust. When this is to be done, the top and base may be made 5% in. square to give a little additional edge-space in which the celluloid strip may be fastened by gluing bits of 14-in. felt next to it. The next article of this series will de- scribe fully the use of the variable con- denser in the sharp-tuned secondary, ‘as well as methods of-adjusting the primary circuit by using the same instrument. An Easily Erected Antenna for Wireless Operators BOARD ships it is necessary to replace aerial wires at least once a year on account of the action of the salt spray and the smoke and gases from the stack. In Popular Science Monthly constructing an aerial it is usual to secure spreaders the proper distance apart and stretch the wires between. This necessi- tates the removal of the spreaders and their holders from the ship to the wharf or clear space where the work can be done, and often requires the labor of from two to four men for at least one day, depending, of course, upon the size of the aerial. To hoist the new aerial into place requires another half day, with additional men to assist in clearing the wires from davits, funnels, etc. The aerial aboard a government vessel had to be renewed recently under a guaran- ty that the vessel would not be laid up, that the radio apparatus would not be kept out of operating condition for more than one hour, and that the same spreaders and attachments would be used. The pro- cedure to meet these conditions was as SNAP HOOK PATENTED SLEEVE Ordinary snaps used on aerial lines to place them in position quickly on a vessel follows: The phosphor-bronze antenna wire was measured off into the required lengths and a snap hook was fastened to each end. Inasmuch as heat applied in soldering this kind of wire invariably weakens it and makes it lable to part — under strain at the point where the heat — was applied, soldering the joints was dis- pensed with and patented sleeves or con- _ nectors were used. This allowed also greater speed in the construction. When all the wire work was complete the old aerial was lowered to the deck and the wires quickly cut away. The new aerial was snapped into place and hoisted aloft. The actual time required in making the change was less than one hour, and the services of three men were required to hoist it in place. The making up of the wires, hooks, etc., can be done by one man, and by using this method an aerial can be installed in one-fourth the time and with only one-third to one-half the labor required by the old method.—F RANK M. MEALS. A New Mercury Interrupter for Spark Coils 4 HE distinctive feature of the break de- scribed below is its independence - from the coil, the cooling of the mercury _ and the contact pieces and the use of water - instead of magnetism to generate the im- _ pulses or vibrations. The drawings show _ the principle of the interrupter. _ Aglass tube A is closed at both ends by _ thestopper B, which supports a hard rubber tube C and a glass tube F. A portion of the hard rubber tube C has been cut away as shown in the sketch and the end of the tube is closed by the plug K. A blade or tongue £ is fastened to C by _ means of a clip D and fits over the opening _of the part that has been cut away. This _ tongue is made from thin sheet steel and carries at the end a contact-piece H which is set close to the mercury G contained at _ the bottom in the outer glass tube A. E If now C is connected to the water main __ by means of some rubber tubing, the water- _ pressure will vibrate the tongue E and the _ contact-piece H will be alternately dipped into the mercury and lifted out of it, thus _ closing and opening the primary circuit of _ the spark-coil. After the water has passed the tongue E _ it accumulates over the mercury till it _ reaches the glass tube F by which it is _ drained away. The water passing over the _ mercury cools it and also the contact-piece _ H and keeps both in a clean state, which _ insures sharp interruptions. _ The break shown in the general arrange- _ ment is mounted in a sloping position, so as _ to use as little mercury as possible. To make the interrupter, procure first a _ glass tube 2 in. in diameter by 9 in. long. Have it cut to the right length in the store where you buy it, as it is very difficult to make a neat job of it and you may break _ the tube in the attempt. Next procure 2 soft rubber stoppers to fit the tube and see that these stoppers are a water-tight fit. Bore a hole in each stopper to admit the tubes C and F. Next take the tube C in hand. This is a hard rubber tube. %-in. bore by 6144in. long. A portion 3 in. long must be cut away as shown in the detail drawing. The easiest way of doing this is to cut to the depth required 3 in. from one end with a fretsaw, and then to file the tube down till the distance from the center of the tube to the cut-away part is 4 in. Next fit a cork stopper K, 14 in. in diameter and Popular Science Monthly > 479 V4 in. long into the end of the tube C that has been cut away, and cut off the pro- jecting part. The tongue £ is now cut from thin springy steel to the dimensions given in de- tail drawing. A small copper-strip H is finally soldered to E and bent so as to be at right angles to the mercury level. The clip D is made from thin sheet steei and fitted around the cut-away part of C. The tongue E is next soldered to the inside of D so that the tongue is lying flat against the tube in the entire length. of the cut-away part. Tongue and clip are now given 2 coats of good shellac varnish, but the contact-piece H must be left free from varnish. To assemble the interrupter put the 2 [ - | SECTION X-X | Ix L cs 7 es z 6 “H SOLDERED oy O_ I 4 / SHARP EDGE | ik 2 ares a The parts of the interrupter which is operated by means of a flow of water instead of magnets f' Toe Ee Ly ne tubes C and F in position. After having soldered a No. 12 gage copper wire to the top of the clip E£, this wire is carried through B, as is also a second wire that makes contact with the mercury. Next pour some mercury into the glass tube A and bend E so that H is about 1/32 in. above the mercury level. The tube is then mounted on a board by means of 2 small clips. The 2 wires from D and G are connected to two binding posts mounted on the board. To regulate the number of vibrations per second, slip an adjustable pinchcock over the rubber tube from the water-main to tube C, and use this as a means of govern- ing the flow of water. <3 480 High Frequency Tesla Coil for Electrical Experimenters NY one who owns a wireless equipment has the apparatus necessary to operate this coil. It should give at least a 6-in. spark under favorable conditions. The drawing gives the necessary dimensions and shows parts cut away, in order to make the construction clearer. The only apparatus necessary is a spark-gap, an induction coil or transformer and plate-condenser. ¢ ; SPARK GAP 14 I 12" 1 PRIM. SEG. WIRE COIL | = J HEE 4i{ i ba) s Pitteurcag ae i ome COIL 1 7 PRIM. yd CONN 4) i 3 TESLA COIL, IND. COIL * Detail of the high frequency coil and the dia- gram showing how to connect the apparatus The primary winding consists of 22 turns of No. 14 rubber-covered copper wire wound ona fiber tube, 6 in. outside diameter, and of a length that will hold the 22 turns of wire. The secondary coil is made up of one layer of No. 34 double silk-covered wire, wound on a tube 3 in. outside diame- terand12in.long. The tall posts carrying the high potential! spark-gap should be at least 18 in. high. Fasten the parts to- aS Popular Science Monthly gether with glue, and do not use any nails or screws except for fastening parts to the base. Finish all over with two or three good coats of thin shellac, drying well between coats. It is well known that a spark drawn from a coil of this type is not dangerous and only a slight burning sensation is experienced when it passes to the body. Sparks may be drawn from any part of the body with- out discomfort to the operator, but to the astonishment of the onlookers. This coil may be used quite satisfactorily for enter- tainments or for various high-frequency experiments. The diagram shows how to connect the apparatus. Testing Wires and Battery Terminals for Polarity with Litmus Paper OLARITY indicators are expensive instruments and the testing of a few wires would not warrant the purchase of one. One simple test method utilizes litmus paper. Procure from a local drug store some red litmus paper and thoroughly soak it in a solution made up of one table- spoonful of salt to a glass of water. When it is thoroughly soaked remove the paper carefully so as not to tear it, and hang up to dry where nothing will touch it except the hangers. Never dry it between blotters. These test papers are used as follows: Take a piece of the paper about 1% in. long by 14 in. wide and slightly moisten it and place the ends of the wire to be tested on the paper so that they will be about 34 in. apart. A deep red spot will appear on the paper at the end of one of the wires and a blue spot at the other. The red designates the positive and the blue the negative. Sometimes the red spot will not show owing to the low potential difference between the wires, but the blue will always appear, designating the negative wire. There are two kinds of litmus paper, red — and blue. If the red cannot be obtained get the blue, but the potential difference between the wires will make the red show up more in this instance. After using this paper it can be dried as when taken from the salt solution, and used again. The Editor of the POPULAR SCIENCE MONTHLY is always glad to hear from readers who have made simple and useful things for the home and the shop with their own hands and who would like to tell others of their own success. Articles from amateur mechanics, electricians and wireless operators are paid for on acceptance, promptly and liberally. But contributors must understand that only unpublished Near i <)> offered exclusively to the POPULAR SCIENCE MONTHLY, are desired. Kaeo . ah eat eran tattle ( cere ws ee Simon Lake, Inventor of Submarines TTEMTUONUTTATOT EOE O COURS TTUUTSUCET OOOO AUSTEREO TEED EES EEE ] bid tl i BEROEOANAG LEEEEEELEEELELEEE] EEE EELEEEEEEEEEEE ORASHOANENE ABR | “To students of Natural Philosophy, Science or the Arts of Mechanics, Chemistry, Navigation and, in fact, new things of general interest to every thinking person who lives in this, the greatest age of scientific advancement, The PopuLar ScIENCE MONTHLY is a boon, and it is “on its job” of giving first information to its readers of the many new and interesting things now being developed.” ~N j AS inns Sole The Life-and-Death Struggle on the Monster’s Back ders “The wounded devil-fish kept plunging below, then throwing herself half out of the water, and as she followed these maneuvers by short rushes on the surface, accompanied by violent blows, I quickly realized that the safest place for the boat was on the fish’s back. The fish was always kept near, and for twenty-two minutes, we had possibly the most dangerous fight ever fought successfully on the water with any living creature. Themonster’s mate was an additional danger.” 482 Pat ind Pes. Paya a Popular Science Monthly 239 Fourth Avenue, New York City April, 1917 $1.50 Annually _FFAXHE American Museum of Natural History wanted to secure a big speci- _ —- men of a devilfish (called by natural- ists Manta birostris) and Mr. Russel J. _ Coles undertook to obtain that specimen at _ his own expense. He is probably the most _ skilful hunter of the devilfish in the United _ States of America. We are indebted to _ him and to the American Museum of _ Natural History for the material on which _ the following article and the accompanying _ drawings are based. __ The devilfish is the largest of all the fish _ known as rays. It owes its name to its - appearance—an appearance given by a pair of flaps or feelers, one at either side __ of the mouth to help in feeding. __ Mr. Coles decided that ordinary methods _ would not do. He says: _ “I found that both sharks and rays sometimes con- tinue fighting long after both brain and heart have been pierced by lance and bullet, but that death is instantaneous when the spinal cord is severed at a Certain spot just back of the brain. . . . I therefore designed and had forged a huge lance, more than three times as heavy as a whale lance, which I calla ‘spade lance’ on account of its having a square cutting edge four inches wide.” A devilfish once towed a 100-ton vessel far out to sea, and the crew had to cut the rope and let the creature escape. In view of the creature’s strength, Mr. Coles de- cided that he would have to invent some way of bring- ‘ing the devil- al ee After the long fight, it took ten hours to tow the big fish to shore. The “horns” on each side . _ Fighting the Terrible Devilfish The story of a thrilling hunt con- ducted in the interest of science fish to close quarters as soon after harpoon- ing it as possible. To this end he designed a drogue, or dray for offering the greatest possible resistance to a puli. In his account Mr. Coles says: “T also carried a very powerful repeating rifle and a large shoulder whale gun, from which either a harpoon, or a bomb lance containing half a pound of powder, can be fired. . . .” . Insecuring his specimen for the American _Museum of Natural History, Mr. Coles had with him, in addition to Captain Charlie Willis, the best known and most efficient fisherman on the Florida coast, Captain Jack McCann, who selected the three other members of the crew—all young men, trained, active and without fear. Captain McCann also furnished the boat which was a small twenty-six-foot open boat with an eight-horsepower gasoline engine. In killing a devilfish it is necessary for every man to move instantly when the word is given, like part of a perfect machine. The procedure is thus described: “Charlie Willis stands forward with me to throw the auxiliary harpoon; Captain Jack McCann steers the boat; another man stands just behind me to throw the drogue overboard as the harpoon leaves my hand, and to give me my spade lance; the next man runs the gasoline engine, while the last stands ready with a bucket to bale water should this be- come necessary. All, including myself, are ready at a word to throw their weight on the high side of the boat if it should begin to turn over,” of the huge mouth are here rolled up. The instinct of the animal is to clasp these horns around any object that bars progress. A blow from one of the huge fins is likely to sink a boat 483 484 The first encounter with a devilfish came suddenly with a most terrific shock which threw: the four men who were standing, to their hands and knees. “The boat, which was running at full speed, had met the head of a Manta, rising to the surface and coming toward us at moderate speed. The shock of the collision was so great that it almost stopped the headway of-the boat, and its bow was lifted more than a foot out of the water; but our speed carried the boat up over the high part of the back of the Manta just as the two great black fins were flung madly into the air, almost meeting over our heads and deluging us with many gallons of water. Then the two fins crashed down on the surface of the sea with a noise that could have been heard for miles, and the Manta in- stantly repeated the performance as I yelled to the engineer, ‘Keep her go- ing.’ Just as the boat was sliding from the back of the crea- ture, another huge Manta rushed up from below, striking full on the port bow with sufficient force to spin the _ boat around_until its direc- tion was almost re- versed. At one time all four of the great black pectoral fins were towering above the men in the boat, and large quantities of water were flung into the bottom. First the head and then the stern of the boat was highest as it was pitched from side to side, and then the chug, chug, chug of the racing propeller blades could be heard as they gashed the tip of the pectoral fin of the first Manta. The engineer kept the engine going at full speed, but the propeller blades were not catching the water, and for a short distance the boat was carried upon the broad backs of the two monster devils of the sea. “Scarcely a word was spoken until, in the midst of a wild upheaval of the two madly frightened Manta beneath us, the boat was flung from their backs and was turning over, when I shouted, ‘High side!’ which order was instantly obeyed, two of the men, except for an arm and a leg, throwing themselves entirely out of the boat. “The boat struck head first and shipped a lot of water over her bow, but we were now clear of the two Manta, who raced together on the surface for a short distance.’’ — Almost in an instant the boat was cleared of surplus water, harpoon and ropes were rearranged and Mr. Coles and his crew were in pursuit of the two Manta, when sud- denly the fish went below. In the distancé he saw three specimens, but all of them were under thirteen feet in width; then the first two came in sight again, and after that they were seen many times. The first Popular Science Monthly It is possible to kill one of these monsters with Mr. Coles’ specially devised spade lance by a single well- aimed thrust just severing the spine back of the brain showed the bleeding fin tip which had been cut by the propeller, and its mate had lost about eight inches from the tip of one of its fins in some former encounter. “These two Manta appeared to have lost all fear of the boat and its occupants;’ we were many times in touching distance of them and they both passed under the boat several times. The first was a female, well above fifteen feet in width, and I was about to attack it, when I saw, nearly a mile away the largest Manta that I have ever seen. It was on the surface so I ran the boat down to it, and never — ‘have I wanted to kill any one thing quite as badly as I wanted to kill that great fish, for it - was fully twenty-four feet in width and must have weighed not less than twelve thousand pounds. I was uncertain how- ever, as to its gender, and a female was ab- solutely neces- sary, also I had only fifteen hun- ter of Paris—not enough to cast such a huge beast; but the principal drawback was that we could not tow such a mon- ster with the little launch and there was no other boat in sight.” For more than two hours Mr. Coles and his crew moved among the six devilfish, hoping that some other boat would appear to help in towing the carcass of the big one. None came and finally Coles decided to kill the first into which he had run. ‘“‘We moved to the attack. As she was passing, quartering across our bow, I gave the word. Charlie and I drove our harpoons deep into her broad back; then, with a great splash of her fins, she plunged below and ahead. As the drogue was snatched under, it threw water high in the air and the’ shock was so great that it brought the great ray to the surface in that awkward, wheeling, edgewise leap that Manta make, after the manner of a wheel turning over. Before its tail had reached the per- pendicular, I and all of my crew saw an embryo, folded in cylindrical form, thrown high in the air, and I heard Captain Jack exclaim, ‘Did you see that? The young one has a tail longer than the old one!’ The embryo quickly unfolded its fins and, catching the air horizontally, its descent was retarded until after the mother fish had disappeared beneath the surface. “When I had hurled my harpoon and reached behind me, the spade lance had been instantly placed in my hand, but as I saw this embryo feebly flapping on the surface, I passed back the: spade lance and yelled ‘Give me an iron, quick!’ (the harpoon is always called an iron) and while not five seconds were taken in the exchange, that was too dred pounds of plas- | eC el a) De ay ATW A x He TUES OREN Pe NTF ( Popular Science Monthly 485 Modeling the big Coles devilfish in the American Museum of Natural History. The underside of the fish measured eighteen feet from tip to tip of the large fins. The tail of the devilfish is normally about as long as the extreme width of the animal. Rough plaster molds of the upper and under side of Mr. Coles’ big devilfish were made on the beach after it had been landed. These were sent to the American Museum in twelve sections and after having been put together were used for the making of a cast. The photograph shows Mr. J. C. Bell at work upon this cast perfecting it in detail. After this another mold was made from the perfect cast and another light cast from the perfect mold. This last cast was colored and the model is a lifelike representation of the great devilfish in every particular. long, for as I threw back my hand to strike, the male swept the embryo beneath the surface with one of its fins. “I passed back the harpoon and seized the spade lance, as I saw the wounded female, now on the surface, charging down on us at highest speed. I was forced to strike instantly and there was not sufficient time to clear up the line attached to the lance handle, so the point of the spade lance was slightly deflected, with the result that the fatal spot Was missed by a few inches. However, the force of the blow, which was delivered with both hands with- out releasing the handle, was so great, that it de- pressed the creature’s head, and the head-on collision did not crash in the side of the boat as it probably would have done otherwise. The top of the head struck the bottom of the boat, breaking the lance handle short off against the side, and I was con- fronted with a very serious defect in my equipment. I had acquired, by years of work with the lance, such confidence in my ability to place it where I desired that I had not thought it necessary to provide more than one spade lance; ‘but now my fish was very much alive and fighting mad and I was without a spade lance. “With this gone the danger was much increased, as the fight had to be carried on with the old-fashioned whale lance, which I had made with the shank only three feet long instead of five or six feet as in the lances used on whales. The big drogue kept the fish always near, and we had possibly the most dangerous fight ever fought out successfully on the The tail has not yet been put in place on the model shown in the picture water with any living creature. The wounded devil- fish kept plunging below, then throwing herself half out of the water, and as she followed these maneu- vers by short rushes on the surface, accompanied by violent blows, I quickly realized that the safest place for the boat was on the fish’s back, and I directed accordingly.” The water was so thick that the devilfish could not be seen until very near the sur- face, but the slack of the harpoon was kept hauled in and the line showed the direction in which the fish was traveling under water. So well was the boat handled by the helms- man (Captain Jack McCann) that not once in more than a dozen rushes did the devil- fish reach the surface without finding the boat on her back. Each time Coles drove the lance to her heart or brain one or more times, and after the fight she showed twenty-three wounds. No attempt was made to use the Winchester rifle or the big whale gun. This Mr. Coles attributes to every man’s lust for blood in a fight. The blade is more satisfying than the gun. The dying Manta finally gave up the ghost with a loud harsh bark or cough. HEN . next your best friend invites you to take a trip on his yacht, do not refuse just because you do not happen to see anything that looks like a life-preserver around. He may have fitted out his deck chairs with life-preservers that serve as cushions. Practically everything that is upholstered can be made into a life-preserver. The mattress you sleep on at night, the pillow under your head and the deck chairs in which you lounge during the day all can be designed to float and help you float if disaster overtakes the ship. The most interesting of these _life- preservers is contained in the easy chairs which invite you to rest on the deck. The comfortable leather upholstery may be removed from the chair in a minute The chair cushions in position on the body as a life-preserver It takes only a few moments to adjust the kapok cushions. They have a buoy ancy of one hundred and forty pounds The Life-Preserver Chair Cushion A new idea for pleasure yachts and steamers and fitted on a person as a life-preserver. When the time to take to the water arrives, you simply rise from your chair, grasp the cushion which has been supporting your back and raise it up. You will see that itis attached by two straps to the cushion which forms the seat. Lift the cushion over your head so the two straps rest on your shoulders and the seat lies on your chest. Two other straps attached to the cushion and the seat are readily adjusted so the life-preserver fits you correctly whether you happen to be stout or thin. The straps fasten with snappers and you may hook yourself into the life-preserver with all the expedition with which a fire- horse gets into his harness. The material used in this type of marine upholstery is kapok from Java. The seat and back cushions are connected with two straps. The seat fits over the chest not absorb water and is exceedingly buoyant. It is equally attractive for the purpose of ordinary .deck upholstery as real leather, which it very closely resembles. The chair cushion life-preserver has’ a buoyancy of one hundred and forty pounds while the ordinary life-preserver only boasts about twenty-seven pounds buoyancy. 486 This will . * at ee ee eT ee ee ee, ee Re ee ne ee eS a en See ey eee ae eee ee Te a a ee a " ™ — _ arranged on each Popular Science Monthly Sun-Glasses—A Sure Antidote for the Baseball Muffer ANY a baseball game has been lost because an outfielder muf- fed a fly ball when the sun got in his eyes; and many a baseball player has had to bear up under sharp criticism at the hands of angry spectators when the sun should have been blamed. Catching a ball ~ against a blinding sun is not only a difficult thing to do, but it is extremely in- jurious to the eyes. If they live up to the claims of their inventor, who is none other than - Fred Clarke, veteran Pirate manager, the glasses illustrated will enable the player to catch flies in the face of the strongest sun. The glasses are riveted to the peak of the cap and work on a hinge. When not needed to shield the SS. they rest against the When a ball is hit the fielder simply a touches the rim of the glasses and they fall 5 down i in front of the eyes in just the proper _ position so that he has a chance to see the _ approaching ball even though he is looking directly at the sun. The glasses can not fall off, and they can be shifted out of the way with the quickest kind of a move- ment when not wanted—two eee which make them far su- _ perior to the old style of “specks.”’ As they are not in- tended to fit the bridge of the nose, they should be so --wearer’s cap that ' when needed they will fall soma in ront of sof theeyes. The ‘ peak of any . lightweight cap is strong enough to hold them. With the new glasses to shield his eyes, the outfielder can “‘pull” a fly down from the clouds directly in the face of a blinding sun 487 The Book Theater. Open It and You Have Actors and a Stage HERE are not many au- thors whose books are played upon the stage. Butoneauthoress, Chris- tina Catrevas of Brook- lyn, New York, will not be one of them. She has developed a book which is itself a stage while the con- tents of the book form the actors. : She explains that when the book is placed on sale, it is folded up so as to condense in it both the stage and the actors. On .. the front cover the title of the play is printed, just as on other books. When the book is brought home it is opened up, and after a few alterations are madea Miniature stage is formed asshown in the illustration. Theactors are then made like or- dinary cut-outs, for the contents of the original book consisted of gayly colored fig- ures printed on its light cardboard ‘“‘pages.”’ These cut-out figures represent the various characters of the play that is written on the cover of the original book; and when they are ready, the play may proceed in whatever way the imagination of the child dictates. The cut-outs may be made to imper- sonate the characters and the scenery in any other story-play, also. A clever new game is this. The book is made so that a child can unfold it into a miniature stage with actors Cross-Country Golf—The Surrounding Landscape © es ; — be * : wicge SA 7 as mS vali, hes — —— a ee wits Ae & icadite De 6 ete t st ee A perfectly good course as cross-country golf goes! Instead of chasing your ball three and a haif miles on a regular greens- ward you pursue it the same distance over swamps, through farmyards and what not Now and then a railroad track gets in the way. The idea is to get the ball over the tracks before the train comes—in other words, not to spend too much time be- tween trains lest the ball escape me wl ~ x Photos by Edwin Levick The height of good fortune in cross-coun- try golf—a level spot from which to drive off. The game plays havoc with golf balls, which are more often lost than found over the un- familiar cross-country 488 a Loot, Takes the Punishment and the Players the Prizes ay elt NG Fa Sp = = = a = t mG 2 & = ‘+ Ah! not so bad! The caddy is trying to follow the ball’s flight as it dodges through a young forest. He doesn’t know whether he will have to climb a slippery elm to recover it or not "Way down yonder in the corn field— considered to be a very poor golf course by the best players. It’s a lucky thing for the farmer that he cut his corn beforehand A little thing like a windbreak doesn’t bother the devotee of the cross-country game. The thing which does peeve him is to waste three strokes at it 489 One Unwelcome Way of Greeting Enemy Aeroplanes To guard the shores of Long Island, New York, against aerial attacks the Government has installed a five hundred million-candle- power searchlight on the aviation field at Hempstead. The light is to be used in co- operation with anti-aircraft guns, to locate and destroy any invading enemy craft ee, a To test the searchlight, aviators will go up in biplanes, followed by ‘‘enemy” craft. The huge light will “find” the enemy, after which our aviators will emerge from the darkness and give chase. If any of the enemy escape, our men are supposed to follow them beyond the searchlight radius until they are captured Photo Central News SF a ae ee eS a eT eS ee Te es { ' ee, Pa 3 > aie “Seein’ Things” in Slabs of Rock When Paul Herzel sees a piece of solid rock it suggests to him an arimal or a group of animals, and he begins as soon as possible to make the rock take the shape that he has in mind so that everyone may see it as he does. So well does he succeed that he was awarded the Whitney and Barnett prize for animal sculpture at the Academy exhibitions of 1915-1916. Note the expressive faces of the animals and the suggestion of agility and strength brought out in the muscles NU anc SIRE ~ LS Below: Sixteen-year-old Albert T. Stewart, who also dreams dreams and sees visions of © animals in the rocks. He is fond of repro- ducing prehistoric types, and is shown in the photograph at work on the ancient ancestor of the tiger. His model is a very up-to- date specimen in Central Park Zoo, New York city. His models are attracting con- siderable attention in the art world from critics of note who consider them rich in sug- gestion, expression, and in accuracy of detail 491 Birds of All Feathers Flock Together RATT mac. OE EM B83 EBS. lb Photos © Brown & Dawson A paradise for birds at Darien, Con- necticut. Ducks mix with pigeons, swans, geese, cranes and all their feathered cousins and live a contented life apart from gunners and poachers. They are bred from purest stock end sold to the owners of private estates The crown pigeon is an orna- mented member of the Darien colony, and by far the proudest. He doesn’t associate with the web-foots. There is a steady demand among the collectors for prize birds in the pigeon family iti ai pene We AT ih When They Are Not Molested by Man A community plunge. The birds’ wings are clipped so that they cannot fly away. In the swimming melée are ducks of all descriptions and a few haughty swans, milk-white and black In oval: The mute swan is in the aristocrat class. Although he is rather particular about his surroundings, he is willing to take up an abode almost any place where the food is palatable The crane lords it over all the others. He is not as popular with the large estate owners as the swan, mainly because he is so destructive. But he is a strong, healthy bird, capable of defending himself, and he is certainly of decided value as a decorative feature 493 Is Inquisitiveness a Scientific Asset? Perhaps At top of page: Miss E. L. Valentine, a bacteriologist employed in. the laboratories of the New York Board of Health. In the photograph she is shown engaged in the study of the germs of pneumonia and colds which germs have been injected into rabbits Lower picture at left: Miss Clara Thayer, B.S., at work 'on water analysis in the Lederle Laboratories, New York City, to ascertain its purity and to determine its possible effect not only upon human health but on the interiors of steam boilers AQA Louise E. MacRoberts, shown in the lower picture at right, is considered an authority on the mosquito, its sins and the best means for its extermination. She is engaged as an expert parasitologist in con- nection with the University of California That’s Why Woman Is Advancing in Science The Dairy Division of the Department of Agricul- ture has a competent bacteriologist in the person of Alice C. Evans. She specializes on the study of microscopic organisms and their direct relation to health and to the keeping qualities of dairy products The tapeworm is not the pleas- antest animal in the world. Yet Mrs. Edna Watson Bailey has found it an interesting study. She was the first scientist to discover that the much-talked-of micro- scopic “‘head’” does not exist at all. She is here shown study- ing the “Chimaera,” or angel fish Dr. Adele Jaffa, of Berkeley, Cal., is an authority on dietetics and a lecturer on the subject. Her planned diets have been followed closely in orphan asylums and in the “Better Babies’ campaigns Photos © Prezs Illustrating rv. Miss Anna Maude Lute, scien- For more than twenty years Mrs. F. W. Patterson tific assistant in the Department has been engaged in studying microscopic forms of Agriculture of the University of life. Her work also comprises study of fungous of California, is a specialist on diseases of plants and the best methods which seed analysis and her work is are applicable for their eradication. Mrs. proving invaluable to the farmers Patterson is also an authority on mushrooms AOS A Million-Dollar School for Seventy-Five Pupils The High School building of Bristol, R. 1, was a gift to the city by Col. Samuel Colt, in memory of his mother. It is of marble throughout, with framework of doors and windows of solid bronze At left: A stained glass window in the Colt Me- morial School, showing the city of Bristol in 1812, when the British were driven out. The seats and chandeliers in the audi- torium are also of bronze The average attendance at this million-dollar school is seventy-five pupils, some of whom are shown below grouped aroundoneofthestatuesby the famous sculptor Rodin, in front of the building © Int. Film Serv. ie ae ed rd Rae tal) A Transport Victim for Davy Jones’s Locker In oval: The transport Sumner aground off Barnegat Light. The big ship -has been buckled and broken in two by the relentless sea and most of the superstructure has been battered to pieces against the numerous rocks At bottom: The Sumner breaking up on the rocks which are to be her grave. Her engines and other interior equip- ment were ruined long before she was given up by the crew as a total loss. No attempt will be made to save her A Thousand-Dollar Piayhouse for a New Orleans Miss Young Lothario making love to Theone Hausmann, on the doorstep of her elaborate New Orleans playhouse which is valued at one thousand dollars Below: Theone’s coming- out party given in front of her playhouse. Many a New Orleans father is fac- ing an imperious demand for a house like Theone’s © Int. Film Serv. A garden at each window and the mistress looking out. The house must be kept clean and the gar- dens must be tended, so it is not all play for Theone At left: The playhouse, which is large enough to be lived in comfortably. Theone spends most of her time there except at night when it is dark | ; d ; 4 4 5 a . a ] q 4 q 3 a : 4 Sling-Tennis—Played with a Bean Bag = ce 1 Ty ETE NT Oe ee ou z ade. Sling-tennis, a lacrosse-tennis-bean bag game, is played with a slackly strung racket and an ordinary bean bag. A sling-tennis court is shown above. The top of the net is level with the head of a man of medium height, but it may be lowered for children or as desired It’s a game fast enough for a ranking tennis player and simple enough for little girls in hair-ribbons. The main principle of the game is not striking but catching and throwing or slinging, as in lacrosse. The scoring is almost identical with that employed in tennis 499 Shackleton’s Ship, the Endurance, Going Down in onset Bringing food to the dogs, whose kennels are the little snow mounds. Dogs were of little use; for after the ship went down all traveling was done in life boats Sir Ernest Shackleton (right) and Captain The ice field in which the Endurance drifted Worsley watching the ice crush the Endurance. for months in the Weddell Sea. The boats, The gallant ship withstood the pressure for eight sledges and provisions were saved and the party months. She broke free once but was hurled back trudged north until they could use the boats raavay the Weddell Sea After the Ice Had Crushed Her Eas = : . 4 3 oe 7 © Underwood and Underwood, N. Y. The Endurance outlined against the three-months-long night of the Antarctic. An oil fire near the bow of the ship helped the camera’s powder flash to light up the place and make possible the photograph. After she sank, the party divided on Elephant Island, Shackleton and five men going for food. After three unsuccessful attempts amidst untold hardships he finally rescued his men Sinking to her grave in the Weddell Sea. The ice broke off her masts and rigging and finally crushed her. When the pressure from the tremendous floes which hemmed her in M was released the Endurance slipped down ~ through the crack. The party then set off in boats. A year later they reached safety Teaching Students the Rudiments of Leather Making A student at Pratt Insti- tute learning to tan hides. He is removing the hair from a skin before placing it in the tanning vats. This is a tedious task Handling the hides in the bark tan vats. The hides are allowed to soak in the strong solution for a specified time, after which they are removed in the manner shown Photos ©) Press Illustrating Serv. A class of students removing the stock from the coloring drum. All hair is removed before the Stock is put in the drum. The machinery used in the process is the most modern <4 a9) pe foal ak OM needa CL het msrp inet " i eos es A Business That Offers Opportunity for the Ambitious Removing surplus water from the hide after washing by working it on a setting-out machine. The hides are run through powerful rollers which remove every trace of water The workman below is removing flesh from the hide by putting it through a flushing machine. This is as im- portant and difficult an operation as removinz the hair Making Cigars by Machinery Mechanism detracts somewhat from the picturesqueness of the manufacture but not from the flavor of the product The tobacco leaves are laid evenly in trays having screen bottoms, and are conducted on an endless chain to the cutting machine hand, which involved much that " recent investigations have revealed as unsanitary, is being supplanted by machinery. Albert A. Heyman, the inven- tor of the device which cuts and rolls the tobacco to form cigars in quantity, guaran- tees that the pipe-dreams ordinarily accom- panying a “good smoke’’ will not lose in quality, even though the increased produc- tion and diminished labor attending it may . reduce the price of the product. He also asserts that it will be possible to open a box of the machine-made cigars with perfect confidence that every one of them will be identical in blend, quality and strength. In the manufacture of the cigars by machinery, the first step is the drying of the tobacco in trays. Then a frame fitted with knives is used to cut the edges, the trays being conducted to the cutting machine on a chain-conveyor, 3; each, tray has a box cover, 5, provided with a rubber tube 6. (See illustration be- low). As the tray reaches the machine the suction applied above holds the layer of leaves up against a wire screening on the under side of the cover. The leaves are then released di- rectly above the se- ries of narrow com- partments shown in Ls old method of making cigars by The trays, with cover (5) and suction tube (6) on the endless chain conveyor (3). suction holds the leaves against the cover The assembled machine, knives placed in_ series, compartments between for the leaf trays the illustration of the assembled machine. — If a blend is desired, each tray may contain — a different kind of tobacco, a thick layer of the leaves being deposited on the machine preparatory to the cutting. The knives on the cutting frame are attached in series, being separated by blocks which press the leaves down into the narrow channels. At the ends of these channels are rollers attached to an endless belt. pressed down tightly into these channels, the belts are set in motion, each moving in i an opposite direction to the one adjoining, so that the leaves will be forced outward. — As the tobacco leaves this part of the ma- — chine, a knife located at right angles to the ~ other knives (see 10, of detail drawing on ~ next page) cuts it into the required lengths. — Thus a rectangu- | is projected into a _ (11 and 12, of detail 4 rollers, 13, 14,aread- 4 justed above and be- — low in such a way that they can be — moved: horizontally The he into position. The 504 After the tobacco has been cut and _ lar bunch of leaves — space, on eitherside _ of which is a roller — drawing). Similar — as action of these rollers is similar to that of a hand shaping the cigar. After the familiar spindle-shape is ob- tained, a binder is placed on the porous belt which passes over the suction box 15. One end of the binder being glued and moistened, it is at once fastened around the cigar. Then the lower roller ‘moves to one side and the finished cigar drops into a pipe below, through which it is conveyed to the cigar box. Detail drawing of the rollers and cutting frame of the cigar- making machine ; Popular Science Monthly 505 the annexation to the United States in 1900, American enthusiasm and American progressiveness have invaded the land. The pineapple industry is one of the best illustrations of the result of this Amer- icanizing. It was started almost by By this method a great quantity cf cigars, uniform in blend and quality, may be cut, shaped and packed 1n boxes in a mere fraction-of the time formerly re- quired and at little expense after the cost of installation of the machinery is met. - How a Boy Started the Hawaiian Pineapple Industry eevORE the United States acquired them the Hawaiian Islands were famous chiefly for their natives and their leper colony. There were no special culti- vation of the soil, no trade, and no commercial industries of value. But since a ee ats “a P #3) » 4c © brows and Dawson chance, by a compar- atively uneducated, inexperienced New England lad, the son of aclergyman. He chose to locate in Hawaii on account of its wonderful cli- mate, and finding that the pineapples were especially lus- cious and that they grew quickly and abundantly, he per- suaded his father to secure a few thousand dollars for him to start him in the pineapple- raising business. It was a veritable get- rich-quick scheme. It has netted fortunes to each one of those friendly parishioners who advanced money for the venture. At first the fruit was sent to the United States fresh and was marketed along the Pacific coast. But now there is a cannery with a capacity of ten thousand cans an hour, from which the fruit is shipped to all parts of the world. Two thousand acres of pineapples, laid out in geometrical designs over the undulating valleys of _ Hawaii. The land is of wonderful fertility in spite of the fact that it is of volcanic origin 506 The ‘“‘mermaid” goggles in use in the picture above. At right: A diagram of the eye showing the convergence of light rays. The parts of the under-sea goggles Eye-Glasses for Divers and Mermaids HY cannot the human eye focus sharply under water even when protected from it? Briefly, because the water makes the eye long- sighted. The human eye oper- ates like a camera lens receiving the light rays from the image and making them come together or con- verge in such a way that half-an-inch or less will be sufficient to reproduce a twenty- foot object. This convergence of light OBJECT PHOTOGRAPHIC LENS ee Science Monthly of one of the lenses, the eye is of long focus and the objects instead of being reproduced in sharp focus on the retina, or back of the eye, go well beyond it and produce only an indistinct impression. A pair of under-sea eyeglasses invented by Dr. Dudgeon, an English physicist, were designed to overcome this difficulty by means of an “‘air-lens.’’ This air-lens con- sists of two surfaces of ordinary glass enclos- ing air and forming certain curves. In air it has no effect at all, neither magnifying nor reducing an object; but in the water it acts as a converger, and shortens the focus of the lens of the eye. Taking Photographs with a ‘‘Shot-Gun’’ Camera HIS gun-camera resembles outwardly the familiar “‘pumpgun”’ or repeating shotgun, with the stock, grip, trigger and slide- handle for the left hand. A small camera of the roll film sort is mounted — in the large muzzle. Pressure on the trigger squeezes a bulb lying below it, which through tubing running to the shutter of the camera in the muzzle, trips it and makes the exposure. SECTION OF The action slide AIRLENS - handle under the left hand is arranged to turn a new strip of film into position for each Z UMOR ‘imace. IMAGE mits the operator of the gun-camera to take pictures as rapidly as he would fire a regular gun of the powder and ‘‘bang,” sort. Regular sights, front and rear, are mounted on the gun to direct it accurately. rays or waves, is due to the phenomenon of refraction. It happens that the “refractive index’’ of the front of the eye is practically the same as that of salt water. This means that the curvature of the front of the eye is lost under water, and the rays of light instead of being deflected by that curvature, as in the air, enter straight. Thus deprived SLIDE HANDLE AiR TUBE OPERATING SHUTTER He merely presses the trigger for the exposure, and rapidly operates the slide handle to turn off a new length of film, without the necessity of removing either hand from the gun exposure, and so per= — oe ae ae Pe ¥ Whe y i t | > Popular Science Monthly © Int. Film Serv The Spaulding Dam—The Largest Power Dam in the Country AT is to be the largest power dam in the country is now under con- struction in Nevada County, California. Stretching across a narrow gorge called Emigrant Gap, this dam will block up _ sufficient water to create an artificial lake nearly thirty square miles in area. What _was once a miniature, lazy stream will thus _ be converted into a mighty lake. _. When completed, the dam will rise three hundred feet above the flooring of the rocky gorge. At the top, it will stretch - across the gorge for even twice this distance. _ The water the dam will control will be fed _ toahalf dozen hydro-electric power plants _ strung along the downstream side of the ” river. _ The water stored by this dam will add one hundred and seventy-five thousand horsepower to the electrical power the United States is already obtaining from her natural water resources. This power will _ be carried over transmission lines a distance of over one hundred and fifty miles to San Francisco. Other cities near the coast will be supplied also. After the water of the lake has turned the turbines in all the power houses; it will then be used to irrigate the lands of the Sacramento Valley. Mita eS The Spaulding Dam in California. The water that it will store will generate one hundred and seventy-five thousand electrical horsepower and will irrigate twenty thousand acres of farm lands Making Buttons, Bric-a-brac and Silk from Milk LTHOUGH anyone will concede that man cannot live by bread alone, it has been thought possible to get along rather nicely if milk were added to the diet. But it remained for two French chemists, Francois Lebreil and Raoul Desgeorge, to conceive an idea whereby milk may also be made to yield a fabric which may be con- verted into clothing and ornaments. The - curds of the milk are subjected to a chem- ical treatment by means of which the mass is converted into a plastic substance which may be rolled into sheets resembling celluloid, from which buttons and other articles such as combs, umbrella handles, bric-a-brac and even imitation leather may be'hade, all of which areof attractive appear- ance and of excellent wearing qualities. The milk is first robbed of its fat, after which it is warmed with rennet so as to form curds. It is then parboiled and exposed to the air, and then it is treated with acetone to give it the required hard- ness, plasticity and transparency. The product may be made so soft that it can be used as a substitute for silk in the manu- facture of fine underwear, or it may be made solid enough to serve as a good imitation of ivory. Under the River with Horse and Cart | An ambitious plan to solve New York’s ferry congestion by subterranean roadways Sa means of relieving the ferry boats A that ply between Manhattan Island and the mainland two highway tunnels under the Hudson River, which will serve New York and New Jersey in practically the same way that the Blackwall and _ Rother- The total length of the tunnels will be eight thousand three hundred and fifty © feet, and at their lowest point they will be — eighty- -nine feet below the surface of the — Hudson River. The rise to the surface on — the Manhattan side will be on a grade of — 3.7 per cent and the grade — hithe tunnels under the Thames serve the city of London, have been pro- posed by the engineering firm which built the two Pennsylvania railroad tubes and the four Hud- son and Manhattan rail- road tubes. The plans are now being considered by the New York State Bridge and Tunnel Com- mission. Despite the increasing number of larger and speedier ferry boats the problem of carrying wagons across New York’s waters is no nearer solu- tion than it was years ago. The advent of the automobile has only served to make matters worse, until, at the present time, over-river traffic is in a state of chronic con- _ gestion. The delays in on the New Jersey side — will be 3.0 percent. The grades below the river will — be 0.5 and I percent. ~ ~One tunnel will be for — eastbound traffic and the — other for westbound. The — roadways will be approxi- 4 mately seventeen feet in — width. The engineers — figure that the two tun-_ nels will have a capacity — of five million vehicles a — year. The Blackwall and — Rotherhithe tunnels, each — consisting of a single tube and providing for traffic — in both directions in one tunnel, accommodated al- most one million vehicles _ in r913, including auto-— mobiles. There are tun-— nels in Glasgow and Ham- — burg with separate tubes — for the traffic in (each: 7 direction. As will be seen in the making deliveries are not only more frequent, but in some cases, particularly at certain times of the year, deliveries can not be made within any stated period at all. The under-river roadways, it is claimed, will eliminate all this. A total of nineteen thousand six ee ae and sixty vehicles crossed the Hudson River on ferries during the year 1913. Not more than two thousand of these vehicles used the ferries north of Twenty-third street. Most of the traffic is downtown. For this reason the proposed tunnels are to serve the congested district by starting from the New York side at Canal Street, practically given over to vehicular traffic as it is, and will enter New Jersey at Twelfth Street, Jersey City. three hundred 508 The districts which the proposed tunnels will serve. length will be eight illustration on the next — page a ventilating duct of large capacity is provided ~ beneath the roadway, with — frequent openings leading to it. ‘Thea engineers claim that the gases of com- bustion carried into the tunnel by the great # variety of products transported from one — side to the other, will settle to the floor 4 The total thousand and fifty feet this method of purifying the < air will be — finally carried out or not remains to be — seen. qi Powerful fans have ale ‘been suggested. 4 as the simplest means to keep the air pure. — Another feature may include the provision ~ of elevator shafts connecting the tunnels 7 with the waterfront in addition to the — inclined approaches. . Bringing New Jersey to New York uly UUUUL] Pr ror M000 TZ VER. SEA LEVEL The old nursery riddle “What is it that is under the water, over the water and yet is not touched by the water?” might well be answered in this age by reference to the vehicular traffic between New Jersey and New York. In the center of the photograph is shown a diagram of the proposed under-river highway which the New York State Bridge and Tunnel Commission is considering to relieve the ferry-boat congestion over the Hudson. Notice the ventilating ducts of the tubes 509 510 If Your Fur Coat Is Dingy Steam Will Restore Its Gloss HEN the old fur yw coat looks as if it were fast approaching the limits of its usefulness do not despair. A fur-coat doctor can put it through a five-minutes course of treatment which will make it fresh and youthful.- He gets his results simply by steaming the coat—steaming it inside and outside at the same time and rubbing it briskly while the fur is damp and hot. The coat is placed over a_ rack. Steam enters the in- side of the coat through a tube attached to the rack. Steam is also sprayed against the outside by a special apparatus held in the hand of the cleaner. Assoon as the steam comes through the coat from the inside, the cleaner brushes the fur until it shines. Five minutes after the steam has been cut off the coat is ready to be worn. The steam. is generated by a gasoline- burning boiler. The sprayer held in the hand is simply a perforated metal disk. Stimulating a Plant’s ‘‘Digestion’”’ by Electricity HERE are several electrical methods in use to-day for stimulating the growth of vegetation. It seems that Steam cleaning by brushing and spraying the coat inside and out at the same time Popular Science Monthly California. In his method, shown in the illustrations, a clay pipe is buried directly under the row of plants. This very porous pipe has a number of electric wires in its walls. The ends of the wires are joined together at the surface of the ground, whence they lead to a source of al- ternating current. It is this current which when carried in the wires courses through the soil surrounding in this way reaches the fertilizer at the plant rootsand stimu- lates the growth. © There are two ways in which the alternat- ing current can be sup- plied. First, the wires — of the pipes can all be con- nected together and run to a small dynamo. This method -is particularly desirable for stimulating the growth of delicate plants, since the comparatively large current serves also to warm the soil. The vegetation raised on an ordinary farm, however, is hardy and this heating is unnecessary. In this case, the current is needed only to act upon the fertilizer. The electricity present in the atmosphere is sufficient. For collecting this electricity, the farmer can erect several wires high in the air. One method of construction is shown in the illustration, although the in- ventor does not mention how high it is nec- essary to carry the wires over the ground. a plant cannot absorb any food from the soil until some of the fertilizer present has been reduced to its simpler chemical compounds. But an electric current coursing through the soil can hasten the breaking up of the fertil- izer into its component elements. Such a current will therefore release greater food supplies in the soil, and the plant will grow faster and to a far greater size as a result of the great supply of nourishment thus produced. Perhaps the simplest of all methods for stimulating plant growth in this way is that recently devised by Warren J. Anson, of Los Angeles, An alternating current carried through the clay pipe stimulates the food absorption of the plants thepipe.Thecurrent | Popular Science Monthly Making Hogs Grind Their Own : Grain Food MACHINE which keeps hogs from squealing, teaches them better table or rather trough manners, and actually _ in grinding their own feed, is a product of _.the inventive genius 511 tion it might be inferred that the hogs require educating to feed themselves with the device, but it is only necessary to sprinkle a few grains of feed in front of the blades and the animals will soon learn how to work it. One of the main features in favor of the device is that it allows the economical feeding 4 3 j _ turns their rooting propensities to account : 3 _-of a Minnesota farm- er. While the inven- tor does not claim that his device will muffle the sounds from a pen absolute- _ ly he has proved that _ the “hog motor’’ is : of value in econom- ically feeding hogs and preventing the _ waste of grain in- evitable with the hand or trough me- _thod of feeding ordizatily employed. / The hog motor is similar in appearance 7 to a small water-driven turbine. It con- sists of a reservoir of galvanized iron fitted ; with a conical weatherproof top into which _ the grain is poured. The grain drops out at the bottom and is F _ automatically fed into a set of 3 grinding burrs Sey _ attached to a mov- _ able set of wooden blades, the whole z being mounted on _ delicately adjusted e ball bearings. The “snout of one pig pushing against the _ blades is sufficient _to set the machine “in motion, and as E the grain is ground “it drops in front of the pig’s snout. In _ endeavoring to eat up the feed the hog gradually pushes the blades around and More grain is dis- pensed. In this way the machine oper- ates continuously, the speed being governed by the agility, appetite and ‘Snout activity of the ‘pigs. _ From the descrip- Photo by E. Bade The fight to the death between the strangling fig and the practically defenceless palm tree One pig pushing against the blades is suffi- cient to start the machine grinding the grain of damaged grain which it would not pay to have ground. The inventor claims that a fairer distri- bution of the feed is possible with the motor than without it; for each hog gets only what he works for, and no hog interferes with another. The Strangling Fig—A Terror of the Vegetable Kingdom LANTS can be as cruel as animals, judged by merely human standards. Just as there are dastardly and cowardly aX birds and fishes so are there murderous plants. That, briefly, is the way in which the strangling fig is regarded. The illustration shows this relentless pest strangling a palm tree, around which it is drawing its sinews tighter and tighter. It is not a parasite; it obtains its sustenance through its own roots. This enables it to grow rapidly, de- stroying its victim inch by inch, until there is no visible sign of the original tree at all. The strangling fig belongs to the same genus as the com- mon fig tree. It grows in the most tropical part of Florida and in portions of the torrid zone. 512 Shooting at Bird-Men with the New French Guns Popular Science Monthly _seconds—something which is altogether 7 unnecessary in point-blank firing. , The gun F you have j ever shot pictured, a : ducks on the eee de- a wing with a +, 18-80 Biot gue , you mounted that have experi- it can be fired — enced some of at the steep- the difficul- ties of the ar- tillerymen who handle anti-aircraft gunson Euro- pean battle- fields. Your practiced bird-shot aims a little ahead of his prey. Beyond this time allowance, he considers nothing. He fires point-blank at his mark. And so it is with the man who fires shrapnel at artificial birds soaring at a height of a mile and ‘more. His task is far more difficult than that of the duck hunter. The allowance which must be made for the movement of the air-man and the. time required: by the projectile to fulfill its mission is not so easily gaged as it is with a fowling piece on the ducking ground. Before the present war, not a single anti- aircraft gun could -be fired point-blank ‘at‘an aeroplane in A new gun, steepest angle. HINGE so mounted that it can be fired at the A perforated weight counterbalances it est angles. It — is so counter- — balanced — (note the perforated — weight at the © right) that it can be swung — about with © the utmost — ease. The — position of — the marks- man shows that hee sights as directly as if he were manipulating a tele- — scope instead of a gun.—CARL DIENSTBACH, ~ A New Press for Preventing the Tennis q Racket from Warping . O prevent the wood of tennis rackets © from warping, a press is used consist- — ing of perfectly straight brackets clamped — on the racket when it is not in use. The — brackets generally used to-day, however, require considerable adjustment to — clamp them properly. They consist — the air. The necessity of that Z of a pair of trapezoidal pieces — proceeding seemed ‘so obvious ff of well-seasoned wood which | that I pointed it out more than — /ff a\ are held flat against the rack- — once before 1914. That it has If et .on either face by four — indeed become essential the | {i | wing-nuts” which clamp them ~ accompanying illustration down and which must cee j abundantly proves. Compared | screwed to exactly the same with this well-constructed and \ i eg | tension. a easily handled weapon the anti- Wet 7), A far simpler bracket has aircraft guns with which Euro- Ss Wy been invented by Fred Ricords, — pean armies were experiment- / of Brooklyn, New York. In-— ing before the war, seem ridicu- — earey aren —C stead of face brackets, two side © lously awkward. They could brackets semi-elliptical in © not be fired point-blank, for Hal shape are used. They take the — example; they had to be | contour of the sides of the ~ sighted around a corner, as it racket when closed together. were, inasmuch as the marks- The brackets are made per- ~ man had to keep his eye glued . : fectly straight longitudinally, — on a reflecting prism. It was The hinged brackets and when they are fitted on necessary to find the range and therefore to lose valuable fit the sides of the racket, holding it rigidly straight the sides, they hold the wood ~ so that it cannot warp. — es Popular Science Monthly If the Road is Slippery, Sand It with the Newest Automobile Accessory OMEWHAT like that of a human arm in operation is the action of the adjust- able sanding device for automobiles shown in the accompanying illustration. Its principal features are two piv- oted fan-mouthed outlet pipes, which may be swung forward or back- ward at the will of the | driver to deliver a large quantity of sand at the periph- eries of the driv- ing wheels, or lesser amountson the road- way in front. The sand is fed from a V- bottomed box, beneath the rear seat through a pipe connected with the outlet-pipes. These are piv- oted on a crosswise shaft which extends beneath’ the vehicle and which is revolved by means of rods and a lever beside the driver’s cab. Rubber-faced disks pivoted on the ends of the pipes keep the sand in when the device is not in use. ' These disks are carried on toggle arms ful- crumed on the crosswise shaft. When the driver moves his lever forward, the outlet pipes swing down and backward, the opening of the disks on the pipes increasing as the lever is moved forward. When the ends of the outlet pipes are nearest the peripheries of the wheels, the disks are fully open. The greatest amount of sand is discharged when they are in this position. In intermediate positions they are not open so wide, so that a smaller amount is deposited on the roadway. BREATHER PIPE FILLER CAP COILS OF PIP Re [NOOO oe wo J CONNECTING UNION me - PIPE LINE TO~ RADIATOR The tank and coil of copper piping under the rear seat are connected with top of the radiator to receive the overflow The road is slippery? Pull a lever and you sand it, just as if you were on a locomotive The sand is fed from a V- bottomed box beneath the rear seat, through a pipe 513 This method for preventing skidding is less severe on the tires than any of the others now in use. Chains placed on the rear tires, for example, tend to wear them- selves into the tires. The indentations they make weaken the tires prematurely. When sand isdischarged under the tires, there is no more wear than when an automobile is traveling over a country road. No indentations are made, and the life of the tires are not shortened as a con- sequence. The sand makes it . possible to travel over icy pavements as well as over roads that are simply slip- pery from the rain. PIPE FROM SAND BOX FLEXIBLE HOSE WHEN PIPE 1S THROWN WHEN NOT IN BACK COVER AUTOMAT— USE COVER I!S ICALLY OPENS TO RE- CLOSED LEASE SAND Novel Tank Condenses Boiled-Over Radiator Water SMALL ‘tank under the rear seat is provided with a coil of copper piping led forward to the top of the radiator. The end of the pipe coil is kept under the surface of the water in the tank, forming a water seal. When the water in the radiator boils over, it flows down the pipe and seeks its own level in the tank where it is cooled. Due to the water seal, the admission of water in the tank causes a vacuum in the radiator and this sucks cooler water back into it, always keeping it full. The} tank has a filler cap which is reached by remov- ing the rear seat cushion. It also has a breather pipe to discharge the excess water automatically should the tank overflow. A Fire-Fighting Truck and Numerous Comforts v ve ee For spraying or fire-fighting—a motor-truck equipped with a power pump which is operated by the automobile engine and a tank with a capacity of twenty-five barrels. The water-tank is detachable A face shield of celluloid or other transparent material which is securely clamped to . the hat rim protects the face from dust and driving wind Cold hands are the special trial of the motorist during winter; hence this electrically warmed steering wheel. Two resistance wires under canvas do the heating Pr tiene ele ee Lig cet ah te spent od The dancing doll on the radiator carries a fan A ‘no-glare headlight which keeps the light within forty-two inches A lap robe ‘for the chauffeur which in each hand. In a above the road. Its range covers the entire front seating space, brisk breeze she be- is five hundred feet retaining all the heat from the engine comes very animated fa A-« i a ee and Conveniences for Cold Weather Motoring A combined baby-carrier and robe-rail for the touring car. The parts are collapsed as at left - end of the photograph to serve as a robe-rail, and distended or assembled to support the baby A folding backrest for the motorcyclist. It folds easily out of the way when not needed. It may be fitted to a cush- ion saddle on any machine A foot muff with an opening large enough to hold both feet and to keep them warm, too A slight pressure upon the lever projects the red signaling hand out fully sixteen inches ——— a An electric heater which keeps the carbureter warm and eliminates the danger of the radiator’s freezing A hollow nut with a coiled spring for An individual automobile for Muggins. It is carried motorcycle cylinders. It shuts off air at the side of the large car and has headlights, tail from or admits it to the cylinders lights and a little searchlight of its own, all of which as the suction increases or decreases work, so that the miniature car may be run separately SIF 516 A child can have no end of fun with these interlocking animals. The head of one can be exchanged for that of another and the most outlandish freaks can be formed Freaks of Nature—And How to Make Them at Home ANY persons have had the opportuni- ty of seeing some of nature’s freaks. But few have had the opportunity of mak- ing them! James J. Kennedy, of Brooklyn, New York, has, however, found a way by which they could do even that. With his wooden animals which have interlocking parts, one can take the parts of one animal and jumble them with those of another, and the freaks so formed may be even more outlandish than real ones. Each of the animals of a set is cut from wood about an eighth of an inch thick. The animals are further cut up to form several joints which are used to connect their heads, legs, and other members with the animal’s body. The sides of these interlocking joints fit closely together, so that the various parts can be held in place securely. ; The joints are allof the same size. -Hence it is a simple matter to unloosen some member of one animal and fit it into the body of another. A. rooster’s head could be placed where a giraffe’s ought to be, or a giraffe’s could take the place of a bird’s! In fact the variety of figures that may be made is limited only by the number of pieces in the set and the child’s imagination, as every piece may be made to fit into every other piece. Popular Science Monthly Footprints on the Sands of Time? No; Handprints in Concrete Per and philosophers have given plenty of practical suggestions as to how to leave enduring ethical marks; but it remained for a contractor and builder of Los Angeles, Cal., to find a way to make our individual impress in the cement side- walks in front of our homes, so that even — the passerby may feel the family spirit of the place. While the builder was laying the side- © walk in front of his new home, his small son availed himself of the privilege of an — only child to get persistently in the way. Several times the trowel smoothed over, — little footprints that marred the surface. — At last the father thought of a way of taking the child into partnership on the © job. He had the boy lay both hands deep down in the drying cement so as to make a well-defined impression, just in the center of the gate-opening.. Underneath, the date — was printed. Thus a mark was made which has defied time and weather and is ~ full of suggestion to the immediate members — of the family. i The idea which was so casually developed — through the presence of a mischievous child, might be applied in other ways which would — make it decorative and of value to anyone — into whose hands the house might even- — tually fall. A fern leaf or other similar — object might be embedded in the concrete — so that a definite outline would be obtained. — On municipal property or in front of public buildings the seal or other emblem of the city might be used. The baby hands were pressed deep into the drying concrete and the date printed under- neath to make a distinctive family mark {hn eee Tea ee eed Popular Science Monthly A Curious Finger Print. How Did the Letters Get There? HE photograph on the right shows a finger print taken of a recruit to the National Guards, mustered into the Federal service. Part of the examination of each recruit consists in the making of an impression of the ball of the fore- finger on a special blank prepared Print of taken immedts soldier is writ 517 Transplanting Wild Animals to Stock the National Parks HE United States is carrying on a very interesting work in exchanging the wild animals of one region for those of others—trans- planting elk and deer and Rocky Mountain bighorns from regions in finger, to te the United States where they are sigeatere of Hlentiful to others where, so far for the pur- as known, pose. The re- eo they have not oe ° ae Sak Je ~ es ~ toe ~ ee Se es ee F 7a cruit signs the zt a #82 & e | lived. Some of blank and : go i : 2 ae ae [ the animals affixes his seal 5 < z eel Se ; are being in the form of He 9 : ; ae shipped long a finger print. i 2 z ee | ‘ distances. When the aime zy f Wyoming is attention of | | = F | | Ly full of elk; the James De- Oa e ean : ce pon H herds in the chene, the re- 2 > s & S F ackson Hole Suit in posed) Miachesae F F . meal are question, was called to the impression which he had made, he was as much sur- prised as the examiners at the raised letters shown. His occupation had been that of a tool dresser for oil well operators, before he enlisted. The tools which he handled were large, and the end which he would : naturally hold was always cool or cold, so that there seemed no explanation as to how he received the lettering on his finger nor as to what the word was of which they formed a part. He could not remember having received any burn or handling any heated stamped metal. The letters UO P LEstood out in bold relief on the recruit’s finger print, though what they meant he did not know the largest of any of North American wild animals since the days of the countless buffalos. But the big Yosemite National Park of California, with its three quarters of a million acres, until recently had no elk, or at least only a very few scattered specimens. But the elk shipped in from Wyoming have become very much at home and are breeding and multiplying rapidly, adding to the charm and picturesqueness of this popular national playground. The photograph shows a carload of yearling elk shipped by the Government from Jackson Hole down into Colorado. A carload of yearling elk shipped by the Government from Jackson Hole, Wyoming, into Colorado. They are lying over for a few days at the Denver stockyards for the sake of exercise Why Zeppelins Are Frightful How a Zeppelin is built, how it | navigates, and how it drops bombs - By Carl Dienstbach HERE are three ways of building a dirigible airship. The first and the oldest consists simply in suspending from a cigar-shaped gas-bag a car in wich the motor is carried. Such an airship (the non-rigid type), made famous in our time by Santos-Dumont, is apt to “‘buckle’’— in other words, to break or bend in the middle: It can never be made very long for that reason. To prevent buckling the ‘““semi- -rigid”’ type of airship was invented— a type in which a stiff keel is attached to the under side of the long gas-bag, from which keel the car is suspended. The French built many semi-rigid ships of large size and proved conclusively that the idea is fundamentally sound. Then came old Count von Zeppelin, with his rigid type. Zeppelin had been an attaché in our Civil War and watched with great interest our attempts. of over fifty years ago to use captive balloons for reconnoitering. An Airship Must Preserve Its Shape at All Altitudes Von Zeppelin had a good deal more in view than the building of a long airship which would not buckle or break in two. When a balloon or an airship of any kind rises, the gas within the envelope expands. At great heights it becomes necessary to let out some of the gas to prevent the burst- ing of the envelope... When the aeronaut drops later to a lower altitude the gas contracts, with the result that the envelope is only partly filled. That condition is dangerous because the strains are no longer distributed properly. What is more, the shape of the gas-bag is not the best for speedy propulsion. Therefore, all airships, with the exception of those of Count yon Zeppelin, use what are known as “‘ballon- ets’’—small air-bags within the big gas-bag. As soon as the airship drops, a blower connected with the air-bag by a pipe is started up in the car, and the air-bag is inflated to such a degree that the gas-bag in turn is distended to the full: Count von Zeppelin wanted an airship that would preserve its shape at all alti- tudes, something that would not buckle. So he conceived an airship which consists of a very light but strong frame several hundred feet long. Within the frame he disposed a dozen and a half separate gas- bags. The outside of the frame was covered with a tightly stretched fabric. From the frame two cars were suspended in the earliest models. The cars were con- nected by a gangway and they contained ; the motors. — . The Art of Building a Zeppelin Is Not Acquired Over Night Now it is immediately evident that a Zeppelin thus constructed will always have — the same shape no matter at what altitude — it may be navigated. What is more, only a rigid Zeppelin can be made large — enough to travel at very high «speed. — Everything depends on speed in a Zeppelin. Moreover, several gas-bags can be punc- — tured without endangering the lives” of the navigators. 4 It is doubtful if any country coulibatet in at once and build Zeppelins. Indeed, — England has tried it and failed. Knowledge ; of the -kind that Count von Zeppelin acquired only after the loss of his entire — personal fortune in experimenting and only — after much financial assistance from the German people and from the German government is not gained over. night. Aa nation cannot merely copy fallen Zeppelins and hope to succeed. It must do oe ral thinking. | Is the Zeppelin the farses Type? It is still much too early to write the — aeronautic history of the present war. This — much, however, is certain: With the ex- — ception of very small British motor bal- — loons, called: “convertible aeroplanes,” and — suitable only for short patroling journeys in fair weather, the Zeppelin is the only — dirigible type that has survived the test of warfare. It seems to have totally eclipsed — even the German non-rigid and semi-rigid — airships. The war has apparently proved ~ that speed is the life and soul of a dirigible, and speed the Zeppelins certainly have when it is considered that they are capable -of making as much as sixty miles an hour — against a twenty-mile wind and are on the © 518 For All Its Bulk, a Zeppelin Has Not Much Substance : St LADDER 1» Tunnel —_ aN | > ’ LEADING TO UPPER ING -POST tf : os 4 N PLATED PLATFORM . RY TYPE | RE GONDOLA, TO RUDDER ‘WITT -CIIRING WAT DERPatts i uc TAS f = WIT SLIDING HATCH SENEATH LATFORM FOR 2 SMALL GUNS A broken-away view of a modern Zeppelin which gives a good idea of its internal construction. In the Zeppelin the gas is confined in about seventeen independent bags which are contained in a long cylindrical frame. A number of the bags may be punctured, but the balloon will still be buoyant enough to carry its navigators to safety and will rctain its shape at any altitude 319 520 Popular Science Monthly whole as fast as racing aeroplanes. Next in importance to speed, come great carrying capacity and great radius of action, both : dependent on bulk. @ Speed makes the Zeppelin practically LA area independent of adverse winds. But speed : TAs is essential not to drive a Zeppelin obstin- cee ee es gh ately against the wind in a straight line : : fe all the time, but rather to overcome an BO AP. MAYBACH MOTOR { ei | a FIRE EXTIN=| rd PORTABLE GUISHER }) PR i vatING STEERING WEGLS “WIRELESS /AERIAL The early car of the Zeppelin and the new car are here contrasted. comfortable. craft aloft. The gas in a Zeppelin (but not in other types because they are too slow) is required for buoyancy only when the ship is standing still or merely drifting. Down on the ground, in starting and land- ing, the gas is a blessing. By giving his titanic structures a speed greater than that of most railway trains, Count von Zeppelin has at one stroke removed all the fatal imperfections of bal- loon support—the fluctuations in displace- ment resulting from the chilling effect of high altitudes on confined gas as well as the changes in volume that take place in rising and falling. I have spoken at some length about speed and the aeroplane lifting effect of a Zeppe- lin because the entire future of the dirigible depends on its transformation when in motion into an efficient aeroplane. More- over, the Zeppelin is regarded both in Great Britain and in the United States as an out-and-out dirigible. Only recently an illustrated London weekly attempted to demonstrate the harmlessness of a Zeppelin by graphically depicting its diminishing gas lift at increasing altitudes. The power- ful aeroplane lift was not considered at all! Similarly, in a presumably authoritative It is roofed over probably to prevent the possibility of a chance spark reaching the gas envelope above rather than for any protection required by the navigators. positions of the machine guns near the motor, which is unfortunate because of the motor vibration The new car is far more Note the American review of European dirigibles, © published just before the war, the aeroplane ~ lift of a Zeppelin was considered negligible. And yet the Germans themselves con- — In one German — official publication, for example, it was — plainly enough stated that without aero- — . plane lift, a Zeppelin would be an impos- — stantly harped upon it! sibility. Advantages of Speed and Carrying Capacity Next to speed, the most astonishing © feature of a Zeppelin is its carrying capa- ~ city. That has its merits, especially in a fighting craft. for speedy journeys. gas. but with just enough to allow for complete expansion at high altitudes. incurred to relieve pressure. The third advantage which accrues to a7 Zeppelin because of its great size, the ad-— vantage of enormous radius of action, is of 7 ek a ee ee ee It means that much cargo can be supported at high altitudes and that ~ the favorable swift upper currents, prevail-— ing chiefly at high altitudes, can be utilized — It costs thousands of — dollars to inflate a Zeppelin with hydrogen © Unlike other airships a Zeppelin need” not be inflated to the full at low altitudes, No loss is Popular Science Monthly minor importance. Radius of action has simply the military advantage of rendering it unnecessary to alight at sea or in the _ enemy’s country for lack of fuel or gas. The frame of a Zeppelin is built like a bridge. But - no one would _ dare concen- trate at one point all the load that a bridge is de- _ signed to sup- port. The load ona bridge and the load car- ried by a Zeppelin must be dis- tributed. Hencethe -newZeppelins have four cars. The two in the center are each sixteen _ feetlong and the others, placed fore and aft, _are thirty feet long. The cars are roofed over in order that a chance spark may not fly up to the gas-bag, with results that may be imagined. There used to be a long well-equipped central cabin between cars into which the crew would retire when off _duty. Now, the crews apparently confine themselves to the cars. The Guns and Bombs of a Zeppelin The most modern super-Zeppelin carries _a battery of nine machine guns—six in the cars and three on top of the gas envelope. _ Two guns are sometimes mounted on the envelope near the bow. This distribution of armament does not seem to make the best use of the possibilities of a Zeppelin as a gun platform, for a Zeppelin is as steady as a rock, except the stations near the motors. Vibrating motors are but poorcom- panions for guns, and the guns on top seem to lack shelter for delicate sighting instru- ments. Perhaps no other arrangement is possible. It must not be forgotten that for all its bulk a Zeppelin has not much substance. In that respect it may be compared with an immense cloud or with a filigree structure. The vibrating motor cars may be the stanchest gun platforms that can be provided under the circumstances. ; t i t E = = 3 t 3 : < ——— st the horizontal rudders, and the lifting surfaces which serve to steady the Zeppelin like the tail feather of an arrow 523 The passage-way between the cars is cer- tainly too narrow for guns. In view of the British aeroplane victories over the Zeppe- lins it may well be that Count von Zeppe- lin’s designers have now decided to invest ; more weight in favorable gun positions. But it seemed wiser to put weight into such strict necessities as a powerful electrical equipment for a depend- able long range wireless equipment; into dynamos coupled with six 240-horse- power motors (dynamos used to sup- ply current to the search- lights as well as for illuminating the cars, for heating and for cooking); into a large supply of heavy bombs and strong motors for speed and lift; and above all, into much fuel for remaining aloft many hours. The bombs are carried under the belly of the vessel, like the roe of a fish. Indeed, in military slang, bomb-dropping is called “laying eggs.’” The bombs are electrically released. Each of the sixty bombs is con- trolled by a button. When the captain pushes a button a 120-pound bomb drops. Americans will naturally wonder whether New York or Philadelphia may not be com- pelled to put out their lights at eight o'clock and conceal themselves. While a Zeppelin undoubtedly could cross the ocean, it could not do so with any great load of bombs. Great as the radius of action of the Zeppelin is, it must remain within naviga- ting distance of its base. And even a Zep- pelin would hardly venture upon a bomb- dropping excursion which would entail a voyage of eight thousand miles, at the very least, without replenishing its fuel tanks. Unlike an aeroplane a Zeppelin cannot alight anywhere with impunity. A Maure- tania must have her wharf; Zeppelin must have its shed. To be sure a Zeppelin, like a Mauretania, can anchor. But she runs risks in doing so. Shifting Gears Automatically It is done by electricity, a mere pres- sure of a button effecting the change There are four buttons, one for each speed- change gear. As these are pushed the gears are moved into mesh by magnetic attraction Interior mechanism of the car. The current to operate the shifter is taken from the bat- tery of the starting and lighting system NE of the electric gear-shifters now on the market, the use of which enables the gears to be changed by the mere pressure on a button, is oper- ated on the principle of electro- magnetism in which solenoids are used. The solenoid is similar in many respects to the common horseshoe mag- net except that whereas the energy of the horseshoe mag- net is permanent and does not vary, the solenoid exerts its power only when electric cur- rent is passing through its coil. As shown in the accom- panying sketch, the simple solenoid consists of a spool around which is wound a coil of wire, the ends of which are attached to some _ current source. A metal rod inserted within the hole of the spool will move to a position where both ends project equal dis- Empty Spool 25 feet of cotton cov- ered copper wire Dry Battery ~ When the spool—or solenoid—is ener- gized by passing an electric current through the coils of wire the nail—or core — moves to a position where the two ends project equally from the spool If electric circuit is closed through spool—or solenoid—No. 1, the steel rod passing tgous the two spools will move to the left, moving gear to the left. If circuit is closed through solenoid No. 2, rod and gear will move to the right A simple solenoid with rod, one of which is provided for each of the change-speed gears 5IA tances from the ends of the spool if current — is passed through the coil of wire. This is the principle of the electro- magnetic gear shift, one sole- noid being provided for each ~ of the change-speed gears in the transmission. A rod with an arm carrying the gear is © inserted in the solenoid. Cur- rent passed through the sole- ~ noid causes the rod and the gear to move back or forth, in or out of. mesh with other ~ gears which transmit the pow- er to the driving wheels. In_ the ordinary gear set with three speeds forward and one~ reverse, four speeds in all, — four solenoids are used. These are arranged in two sets of two each as shown at the 7 bottom of the accompanying ~ sketches. Steel shafts carry- ~ ing gears on arms are placed ~ inside of the solenoids, and as Popular Science Monthly the current is sent through one or the other of them the shafts and the gears are moved in or out of mesh by magnetic attraction. Each solenoid is wired to a numbered bottom in a small case attached to the steering column directly under the wheel, within easy reach of the driver. There are four buttons, one for each speed-change gear, and as these-are pushed, the current is sent through the solenoids as desired, thus moving the gear into mesh. Two gears cannot be thrown into mesh at the same time, as the circuit be- tween each solenoid and its corresponding button is not closed until the clutch pedal is depressed. For this reason the gear into which the driver wishes to go may be selected some time in advance and the change made in an in- stant by simply depressing the clutch pedal and then letting it spring back again. The current necessary to operate the shifter is taken from the battery of the regular starting and lighting sys- tem .now used on most cars. Building a House to Protect a House —How One Wealthy Man Fooled the Weather OU can even make the weather behave, if you are w illing to spend the money. If your contractor is facing serious delays in the way of bad weather all you need do is to build an extra house to keep the weather out. The accompanying illustration shows a A simple stair-guard which prevents care- less people from fall- ing-down stairs and into open shafts 525 temporary structure built around a home erected at Eastern Point, near New London, Conn., by Julius Fleischman. For a while the weather bothered the contractor and it looked as if the home wouldn't be finished at all, whereupon the owner, tak- ing the situation in his own hands, decided to elimi- nate the weather alto- gether by building a house to protect the house. Then the men were able to proceed. A Simple Elevator Guard Which Makes You Watch Your Step GUARD invented by Harry Howe, of Rockford, Illinois, and_ illustrated above, acts both as a warning and as an obstruction to a person approaching an open elevator shaft or stairway. The device, which may be readily - attached to one side of the stairway in the home, consists of a bracket and a guard The weather interfered with the workmen. protecting structure was erected around the house So, a member. The bracket is equipped with guides which automatically keep the guard member in normal position when it is not being operated. In going down the stairway or into the passageway, it is necessary only to raise the guard member above the stop portion on the guide, after which, by slight pressure, it follows the guide, swings to a raised position and returns to the normal position as soon as the person has passed. In coming out of a stairway, a slight pressure of the arm or body swings the guard to a raised position, out of the way. tl Why spend great sums in bombarding the enemy’s entrenched position with artillery when a fleet of torpedo automobiles, each carrying a charge of high explosive, could be launched with The Torpedo Car—It Destroys ‘Trenches Also it takes the place of artillery in preparing the way for infantry attack WELL-DIRECTED bombardment (‘artillery preparation”’ is the polite military term) preceding an infantry attack obliterates breastworks and barbed- wire entanglements, and literally blasts the enemy from his entrenched position. From experience under such a hail has come the fighting tice, preparing the way for an infantry charge entails a staggering cost. For that reason inventors have tried, and indeed still are trying, to substitute some agency which will replace the big guns and do their work cheaper but no less efficiently. The device illustrated, which may be called a tor- ; . MOTOR CONTROL AND man’s dic- PROTECTION CONTROL FIRING DRIVING _ RECOVERY pedo car, be- tum, ‘‘Better EXPLOSIVE GEAR CABLE cause it is CONTAINER to face a whole regi- ment than brave an hour’s artil- : —,* : lery fire!” o 5 _ | But even Seeing aan eae though the er, FORWARD CHAIN RIVE use of modern wid artillery has worked a rev- olution in battle prac- LEVER \ WIRE y oT Me What the torpedo car looks like. Note that the control cable regulates the speed of the machine and that the firing wire sets off the explosive nothing more than a_ tor- pedo mount- ed on anauto- mobile chassis, is an attempt to relegate artil- lery to the | MOTOR abi and substi- tute in its stead acheap, FOR eee ee scrap heap ery One ee ey i a a a al at Popular Science Monthly ag _ effective means of destroying the enemy’s “entrenchments. So far as the actual manu- - facturing cost goes, one of these torpedo cars could be built for one thousand dollars, _ whereas the modern naval torpedo repre- sents an outlay of seven thousand dollars. ’ This, in itself, is an important factor in its ‘favor. Whether or not the torpedo car could withstand the concentrated fire of the defending force, rests entirely upon the distance over which it would have to travel and the material of which it is made. _ Briefly, the torpedo car consists of a torpedo carrying several hundred pounds of high explosive mounted ona chassis. It may be propelled either by gas, steam, com- ed air or a storage battery and electric notor, all depending on its contemplated e and the estimated range of action. _ But the most important feature of the @ar concerns the method by which it is ided and fired. This is done by means f cables and wires in the hands of the attacking party, as illustrated on this page. The control cable is attached to a valve in é€ supply pipe connecting the cylinders of e engine with the boiler, operating the Speed of the car. The charge is fired by “means of a wire attached to the trigger. uunerring accuracy and deadly effect against the barbed-wire entanglements? One of these machines would cost but one thousand dollars; a modern naval torpedo costs seven thousand dollars If it is found that the torpedo cannot reach the enemy because of rough ground, the control cable may be used to close the valve and to draw the machine back to the trench, for aiming it in a new direction. A windlass is provided for this purpose. Spiked wheels insure traction. The torpedo car is provided with a shield of sufficient strength to bear up under rifle fire, as there is little likelihood that the enemy could train artillery on it in the brief period during which it is exposed and the high speed with which it is driven. In carrying out an offensive campaign the inventors, Victor A. Villar, of New York, and Stafford C. Talbot, of London, plan to supply an attacking force with a number of these torpedo cars. Ata given signal these war implements, suitably spaced apart according to the length of the enemy’s front to be attacked, are released. They travel toward the enemy’s entanglements and obstructions with astonishing speed. When they have reached certain desired points, the torpedoes which they carry are auto- matically exploded by pulling the wires attached to the triggers, and everything within a radius of two hundred feet is blown to pieces, including the machines. ec Breathing by Machinery Dr. Meltzer’s apparatus has saved the lives of many overcome by gas in the trenches HEN a man is overcome by pois- onous gases or is shocked into in- sensibility by electricity, he may usually be saved if artificial breathing is at once induced. In order to accom- plish the effects of natu- ral breathing by pump- ing oxygen into the lungs through the throat, ; F ie care must be taken that the air does not escape into the stomach. A breathing apparatus de- vised by Dr. S. J. Melt- zer of the Rockefeller Institute for Medical Research prevents this in two ways. The simpler method he uses is to place a board on the stomach and to hold it firmly in place by means of straps which are passed around the body. The board ex- erts sufficient pressure to make the entrance of air into the stomach impossible. The other method employs a tube inserted in the stomach to remove any air that may enter during the process. RING WHICH CONTROLS ~~—~s The throat tube has a round upper side which prevents the oxygen from escaping Pacey ee AIR TUBE The apparatus consists of a throat tube, a stomach tube and a bellows, connected with the oxygen tank Dr. Meltzer’s apparatus consists of a throat tube which fits the mouth, prevent- ing the escape of oxygen; a stomach tube, and a bellows. The throat tube has a flat side which rests against the tongue, and a round side—the upper side— which reaches to the wall of the throat and prevents the oxygen a from escaping through bn the nose by closing the STOMACH TUBE entrance to the air pas- sages in the nose. A rubber hose connects the throat tube with the bellows or bag and this, in turn, is connected with the oxygen tank. The stomach tube may be attached to the end of the throat tube or not, as the operator desires. When it is not used, the hole in the throat tube to which it is connected may be closed by a plate. At- tached to the throat tube is a valve which regulates the passage of oxygen into and out of the lungs. The valve is controlled by a ring, which when moved to the right causes the oxygen to be forced into the lungs; when moved to the left it causes the oxygen to be expired from the lungs. The neces- sary oxygen is given by the bellows. MOUTH days BELLOWS iRING WHICH. CONTROLS: VALVE > r<— AIR TUBE} BOARD STRAPPED, OVER. STOMACH, In case of failing circulation the board on the abdomen will raise the blood pressure ~shower-bath from Popular Science Monthly This Fireman’s Suit Is Made of Real Water HE Cincinnati fire department has been testing a new safety dress for firemen. The man who wears it can stand right in the midst of flames. He need not fear the glowing embers around his feet. He can walk into a fire and it will dwindle away and go out around him. The dress is made of fireproofed canvas of two thicknesses between which water flows constantly. The water enters by means of a perfor- = ated brass tube which encircles. the neck between the two thicknesses of canvas and flows down between the layers through the arms and legs, finding exits at the finger tips and around the soles of the feet. Water flowing only between the two thicknesses of canvas would not offer com- plete protection to the wearer. To keep him cool and comfortable while standing in the hottest fire, two brass perforated tubes encircle the helmet and give him a constant WATER DISCHARGED iN HELMET Ve PORTS IN HELMET A fireman wearing this uniform stood in flaming wood for ten. minutes without discomfort clock bulletin below. 529 surrounding atmosphere, no matter how much smoke, flame or gases are init. Itis “5 sucked into-a patented collar which fits on the hose just back of the nozzle. The smoky air is washed and purified within the collar and sent by the pressure of the water flowing through the hose, up into the helmet for the fireman to breathe. The foul air finds exit through vents in the helmet. The same collar which washes and purifies the air for the fireman also has the water hose connection which supplies the shower baths in- side and outside of the uniform. How One Hospital Gets Its Necessary Supplies T the Overcliff Hospital, Westcliff-on- Sea, England, there is a feeling that the public only wants to be taken into the con- fidence of the public institutions in order to offer efficient co-operation. So the hospital authorities have introduced the “ Want” and “Thank You” the outside as well as within the folds of the uniform. This not only keeps him from becoming over-heated but also extinguishes the fire around him. In this air-tight water-bathed uni- form some provi- sion must, of course, be made for ven- tilation. The air supply arranged for cannot give out so long as water con- continues to flow through the hose held in the fire- 2 - ; man’s hand It sd Want pm “Thank You” bulletin clock which the hospital ‘ au iti f li i i - ite from - the orities o vercliff Hospital, England, have placed in a con spicuous place on their campus to inform the public of their needs If Helmets fort O one suspected, ten | \ years ago, that at least part of a medie- val knight’s equipment would prove serviceable in modern battles. Yet all the fighting nations, following the example set by the French, have supplied their men with steel hel- mets. Since the helmets have unques- tionably proved their merit, particularly as a defense against burst- ing shrapnel, why not go astep farther? Why protect. only the head? Why not the whole body? Otis L. Boucher, an Ameri- can inventor, believes this perfectly practicable, and he has devised a suit of steel which: covers practically the whole of the front of the body. Each one of its seven parts is formed by two steel plates which hinge sharply together at the front. It is seen at once, therefore, that since the plates are placed at an angle the bullets of an enemy are more likely to be deflected than to kill. The main part of the armor protects the head and body. It is made in three pieces held closely together by a clever ron \ Are Good, Why Not Armor? A suit of mail and a little steel invented by an ingenious American arrangement of catches. are kept in position against the body by a pair of lugs which are built in the inner side The parts of the armor can be de- : tached and the three larger pieces of the body folded along the edges Details of the armor. and body part can be lifted off with a single swift movement ~ all in one—a _ combination ileal i iri Mes The three pieces of the central piece. These lugs, when brought down over the shoulder, prevent the armor from sliding off. The head part or helmet is made of lighter steel than the rest; and it is padded in- side for comfort. The helmet is hinged to the central piece so that it can be raised and thrown back when- ever it is desirable, —and sufficiently safe. Each of the leg PIVOTED SHUTTER PIVOTED HELMET WITH SMALL OPENING +e THROWN eT ee eo ee ee ee a yore orangred FIELD GLASSES: aes HINGED BREAST PLATE ON SHOULDER SHUTTER HANDLE SHUTTER q j : R: ; j rs 4 a £ BELT SUPPORTS THIGH SHIELD : g o PIVOT 3 STEEL CAP PREVENTS EX{) POSURE OF KNEE. AS SHIELDS SEPARATE. WH cots [cut AWAY 70 CON The head LOWER LIMB SHIELD FORM TO FOOT pieces is made in two parts, and each is hinged at the knee and ‘strapped in -place. The pivot-joint allows the knee to be bent to provide for perfect freedom of action in crouching or crawling. her aes Popular Science Monthly General Typhoid—an Army’s Most Formidable Enemy VEN in the present war, for all our boasted sanitation, disease carries off many a man. General Typhoid has dirt and germs for his allies—and they never fail him. To fight him, an army and its camp must be clean. So, an apparently trifling problem like refuse disposal, is as important as supplying munitions. Because an army piles up tons of rubbish and garbage every day, the equivalent of a municipal street cleaning department and board of health is needed. The finest purifier is fire. To the flames, then, all wastes are consigned. A United States army officer has recently proposed that as small a group as a bat- talion of men should be supplied with its own incinerator and its own men to look after the burning of its food wastes. The incinerator approved for this purpose is built in the ground in the shape of a flat T-trench. In the oven of the “T,”’ is the fire which heats the rocks placed in the head of the “T.” The refuse itself is burned on a steel plate placed directly over the oven. The liquid of the refuse drains off from the plate and trickles through holes in the plate, down over the hot stones beneath. . —— GARBAGE PERFORATED siete SS Ss ——— meat mite ~ 7 PLATE7 HINGE YW SS £1 cROCK Y oT 2 OOQ OVEN A RSH ain Uy ZY) 2, OO pdt BLY) POD Wr bey) RAS FI XR This incinerator can be built anywhere and disposed of quickly when no longer needed . The refuse is burned on steel plates over the oven and the liquid drains off through the rocks © Int. aa Serv. * The automobile wireless communication out- fit of the New York city Police Department New York Police Department Uses Motor-Truck Wireless IRELESS telegraphy from moving trains was shown to be practical some years ago, but it remained for the Police Department of New York city to build a;wireless truck that could communi- cate with headquarters while driving through the streets. A complete radio out- fit is mounted within the body of the automobile, and two masts to support the aerial wires set up at front and rear. Power to drive the transmitter is taken from the gasoline motor which propels the truck. Our photograph illustrates the mobile wireless station, as it appeared in [the recent police parade, passing the Public Library at Fifth avenue and 42nd street. Although the city is run through and through with telegraph wires connecting the various police stations, the wireless installations at Headquarters and the police camps are necessary in case of emergency. It fires a shell weighing from 12 to 14 pounds at a muzzle velocity of 1175 feet per second. The recoil action is overcome by discharging a charge of shot and vaseline from the rear the weapon, gives way first when the powder is fired, and travels faster; but the gun of which the breech-block is a part, travels the other way just the same. The nearer the weight of the gun is to the weight of the bullet or shell, the faster it travels, and the heavier, therefore, is the “kick” of the gun. In theory, if the gun were the same weight as the bullet they would fly in opposite directions at the same rate of speed. ' Now if you put a charge of powder in the middle of a gun barrel, and put a bullet of the same weight at one end of the charge as a bullet placed at the other end of the charge, then touch her off, the gun won’t kick at all. The two bullets will merely go off in opposite directions. The expansive force of the gas has operated in both directions as usual, but there was nothing to move the gun itself. So much for a principle well known in gunnery for a hundred years. The recoil of a cannon is taken up by cylinders of air or liquid precisely as the slam of the spring-impelled door is taken up by air cylinders. The barrel slides on ways under the back- b BULLET in a gun, being lighter than A Gun Without a “Kick” It is based on the theory that action and reaction are equal and in opposite directions By Edward C. Crossman ~ thrust of the gas, and its motion is checked by the cylinders and the perforated pistons within. Old types of guns ran back every shot, and the naval crews had to tail on to the tackle and run the gun back into battery after reloading, just as the field artillerymen used to run back their pets after each shot. This was slow, and neces- sitated resighting—termed ‘“‘relaying’’ in gunnery parlance—for every shot. The use of recoil cylinders stopped all this. Presently there arose the need for a bigger gun for aeroplane fighting, both for the other planes, and for the things of land and water the planes didn’t like. Planes are cranky things so far as stability is con- ~ cerned, and it was obvious that you couldn’t have a gun kicking around:in one of them without disturbing things. It was equally obvious that you couldn’t put a two or three hundred-pound gun and recoil mechanism in a plane in which the last ounce of weight was figured, because that meant cutting down speed and raising plane area. Then came the man who could apply a wellknown ‘principle to a wellknown need. He is Commander Cleland Davis, U. S. N., Retired. If, he figured, a gun with a The throw of a lever rolls the rear barrel and exposes the breech end for the reception of the ammunition. Another throw of the lever returns the rear barrel to its former position and locks it 532 Ce a ee ey ere ~ 1,000 feet a second, eT A he al ee oe 1 Oh IR ale Cv Popular Science Monthly 533 powder charge in the center of the barrel, breech end of the rifle barrel for the recep- and a bullet at either end of the charge _ tion of the fixed ammunition, which comes didn’t kick, then a q———__ in the form of a very still bigger gun with |= large cartridge with a shell in the place a 3-inch shell in it. of the bullet, and an This contains pow- equal weight of fine der charge, shell and shot or something of shot. Another throw the sort at the other of the lever returns end of the charge, rear barrel to posi- wouldn't kick, either. : aa. 2 é tion and locks it. So came about the. e: = Ee Le I The complete gun wonderful kickless ee | ; as originally de- gun, a cannon firing | signed, ran about a three-inch | shell seven feet in length. with the velocity of Guard studs on the pivot of the gun are easily arranged to limit the travel within safe angles. Small shot, of course, quickly loses velocity, and the charge drops harm- lessly to earth, while and yet so light and devoid of kick that a man has fired one in his bare hands. There’s nothing to it but what I’ve told you—the projectile ahead of the powder, Because the back end of the gun is nearly as a charge of shot of dangerous as the front end, the pointer sits at the 3-inch explosive weight equal to the the center. However, the recoil charge will shell from the other projectile behind the not perforate a sheet of paper at seventy-five end does the work. powder, two barrels feet. The gun is made of vanadium steel joined at the charge, and no breech- closing apparatus save that which joins the two barrels after loading. When the charge explodes, shell goes one way, fine shot goes the other, down its own barrel. The gun cannot kick because there is no resistance in the gun to the powder pressure, save the chamber walls at the side. The wall pressure, being the same all round, doesn’t tend to move them at all.. The kick is all given to the shot, which is driven out of the back barrel and which falls to the ground as harmlessly asa charge from a shotgun. In the gun as now made, the barrels are made of the lightest, thinnest sort of vanadium steel, the strongest sort of metal. A man can An Old Kitchen Sink Makes An Impressive Plumber’s Sign NEW advertising idea is being used in Los Angeles, Cali- fornia. J. K. McCahan, a plumber, is attracting public attention to himself by an old, hole-worn zinc slab which he has stationed high up over a_ small orange tree in his front yard. The bottom of this novel shingle has been daubed over with white, and his name and his trade have been painted over this in black. No one can pass by this house without be- ing doubly impressed by the fact that here, at least, lives a wide-awake plumber. The very holes in the zinc : ] plate suggest the trade of the easily pick up and carry the man who lives there, without whole gun. the lettering. The place for The throw of a lever at the Guaa's ceaueative ok the sign was decided by the center of the gun rolls over the _ vertising sign for an fact that the little orange tree rear barrel. and exposes the enterprising plumber needed propping. Luminous front and rear rifle sights which enable a soldier to aim accurately in the dark Fighting in the Dark with the Aid of Rifle Night -Sights WELVE hours do not make a working day on the fighting fronts. Even though the grist of the day’s fighting has been heavy, the belligerents sometimes battle far into the night. This they are able to do with the aid of rifles fitted with night-sights, the invention of a British artilleryman. The invention consists of two spring clips which can be quickly fastened to the front and rear sights of the British in- fantry rifle. On the spring clips are painted strips of luminous paint which maxe two rough sighting points by which to direct the rifle. A Gasoline Gun—It’s Somewhat Like an Automobile Motor HE French used to make a little gun that threw its bullet by means of car- bonic acid gas, stored in compressed form, in a reservoir carried below the barrel. When the trigger was pressed, a little valve ad- mitted a quantity of the gas to the breech end of the barrel and blew the bullet out. Now comes an inventor with a gaso- line gun. Under the barrel is carried The firing pin is released by pressure on a thumb-trigger Gun Problems Suddenly the gun has sprung into prominence. Here are a from the carbureter just below. Pressing the trigger closes a circuit in the battery line and ignites the gas charge, driving the bullet out through the spring resistance and through the bar- rel. The pressure of such a gas charge is only about one-tenth of what is necessary to drive even the little .22-caliber bullet from the ordinary rifle. Pulling the Trigger of the Gun with the Thumb ROM the days of the matchlock, when some ingenious gun designer ar- ranged a little slip of steel under the grip of the gun by which the forefinger released the glowing match into the priming powder of the gun, the forefinger-has been pulling the trigger of a firearm. One reason for thisis that when the gun is gripped normally, the neces- sary spring resistance in the trigger is easiest over- come by a light increase in the grip of the upper parts of the thumb and forefinger. — A Brooklyn inventor’ has evolved a thumb-trigger bolt action rifle in which the firing pin is released by pres- sure on a thumb-trigger on the upper THUMB TRIGGER | PEEP SIGHT = 27> / TRIGGER GUARD part of the grip, instead of by the nor-— q mal form of trigger below the grip. Also he protects the thumb-trigger or plun- ger on the upper side of the grip by an open base peep-sight, mounted on the firing pin in a form familiar to owners of bolt types. y- COMPRESSION COMPRESSION CHAMBER COIL a reservoir of gasoline, with a car- bureter behind in the frame of the arm. Batteries are supplied in the stock. The bullet is loaded into the barrel and kept from moving forward by the resistance of a pair of springs. | Thegasoline gun == . : VALVE OPENS ON A plunger at the back end of the So ghteme 2 SUCTION STROKE : : : shoot a bullet by OF PLUNGER breech is used to furnish compression means of a gas- to the gas charge delivered by a valve oline explosion f& PLUNGER FILLER cAP ~——"" GASOLINE COMPARTMENT spark pLuG SHOT HELD IN PLACE AGAINST COMPRESSION BY SPRINGS \ 534 - Simply Solved | _ few ideas which have been pro- 4 posed to increase its accuracy An Iris Diaphragm for Both Front and Rear Sights LIMINATING the objections both _4 to the peep rear sight and to the aperture front sight, Brian C. Bullen, of Paterson, N. J., has done the obvious thing and applied the well-known iris diaphragm principle to both front and rear sights. Just as this form of dia- phragm has supplanted in camera con- struction the old and clumsy form of a rotating plate with various sizes of holes, it has here taken the place of the rotating disk on the rear sight, elimi- nating the make-shift of changing front aperture rings to correspond with the size of the bull’s-eye. The Bullen system consists merely of the familiar rotating ring control- _ ing the leaves of an iris diaphragm actuated - by a pointer or movable button. The _ moving leaves, as in the camera shutter, _ increase or decrease the open- - ing in the sight. r So equipped - the user of the rifle can adjust the rearsight for the prevailing light. ibricating the Rifle Barrel with a Graphite Cartridge IRIS 4 A WASHINGTON man has invented a _ 4 X cartridge containing a charge of pow- _ dered artificial graphite between the powder and the bullet or shell, the graphite con- _ tained between a wad over the powder, and _ ~ the base of the projectile. Artificial graph- _ ite won’t burn up at rifle temperatures, and it is a fine lubricant for steel. When the = esaead burns, the graphite is driven out __ between shell and chamber, lubricating the _ barrel both ahead of _ and behind the projec- tile, protecting the steel _ just ahead of the cart- _ ridge from melting by the powder gases—ero- sion—and lubricating the bore for the passage _of the missile. ot = > bs i SEPARATING WAD 535 With the Bullen system the moving leaves increase or decrease the sight opening The artificial graphite is contained be- tween the powder and the bullet or shell NOTCH IN OPENING PERMITS Using this clip the man firing the revolver can reload the six chambers in two seconds Reloading a Revolver in Two Instead of Fifteen Seconds HE automatic pistol usually carries its cartridges in a detachable magazine. It is quickly reloaded by dint of slipping in a spare filled one, or else, in the case of some of the foreign war-pistols, by stripping a clip of cartridges into the fixed magazine as the soldier strips them into his Mau- ser. This givesa far higher con- tinuous rate of fire for the re- volver. Now comes.a member of one of the famous old American revolver-making firms, with a clip for slipping six shells at a time into the revolver cylinder. He has two forms of clip, one a flat plate with holes cut around its periphery to fit the grooves in rimless cartridges, and with a DIAPHRAGM ON FRONT AND REAR SIGHTS circular spring to hold the cartridges in the clip or plate. In the other spring, fingers opposite each opening hold the cartridges in. Plate and six cart- ridges go into the gun, the cartridges into their chambersin the cylinder, the plate flat against the back of the cylinder. When fired six times, the gun is emptied by a single movement of the ejector rod as usual. Fired cartridges can be replaced with fresh ones in two seconds. An Assortment of Mechanical Kinks Which Lessen A semi-rotary sleet cutter for the trolley pole. It scrapes the ice and sleet off top, sides and bot- tom of the copper trolley wire Left above: A tilting wood band- sawing machine. The saw can be moved to forty-five degrees on either side of the vertical At right: A key- ring which is locked simplyby pressing the out- side of the ring with the thumb HOOK HELD RIGIDLY BY [ SLOTTED CORRUGATION IN BRACKET y i 1 | y, )) “TS RAISED IT CAN BE TURNED TOTHE WALL Above: A combined Above: A coat adding machine and and hat hook typewriter. A_ small which may be electric motor insures folded back out maximum rapidity and of the way minimum effort on the when not -in use part of the operator A steel cabinet for job press accessories. One New foot-mats of wood placed in side holds the press rollers and ink; the other Passenger stations by a railroad to holds gasoline, brush, wrenches, rags and pins take the place of coco fiber mats 536 A screw extractor with left-hand spirals to grip the sides of the hole drilled in the screw that is stuck. It never fails to hold SCREW FOR REMOVING KNIF a ROPER ANGLE A phonograph needle cutter and sharpener, designed for bamboo needles only. The knife may be replaced after it is sharpened A chain-drive bor- ing machine, for drilling holes in joists, rafters or other inconveni- ent places, weighs but sixteen pounds A lawn perforator for reseeding. It is composed of a block of wood and: quar- ter-inch spikes which. protrude about three inches A machine which makes tire changing easy. Rollers are swung around in the reverse of the dismounting direction TROLLEY WIRE JN TROLLEY WIRE IN CENTER ay, Y AUXILIARY GROOVE BEING DRAWN TOWARD CENTER Portable tool-post grinding machine with extension arm A trolley which engages (at the left) for deep in- the wire at all times. If An oil can fitted with a ternal work. It grinds the wire becomes disen- cap lifting prong attached large gages, regrinds gaged it is automatically to the spout. The prong valves and cylinders conveyed back to the can lift the strongest cap and polishes dies center groove, as shown Lor A Power-House as a Futurist Painter Sees It The artist sees the energy rather than the generating machinery that you were asked to paint the picture of a man describing circles with a lighted cigarette held in his left hand in a perfectly dark room. How would you draw the moving cigarette? As a brilliant point of light, as a complicated curve winding in and out? Obviously, you would paint it.as a labyrinth of curving glowing lines. Thus you would give the impression of motion. That being so an artist who paints a dancer with one toe on the ground and another pointing skyward is not telling the whole truth. Dancers are constantly moving, and* to express. their movements, something more must be done than to transfix them in a single attitude. So we find the futurists striking out in a new direction—trying hard to translate S that 90 that you were an artist and house. Frances Simpson Stevens and her rep- resentation in line and color of the energy in motion in a great power- She calls it pictorial velocity motion into color and line. You may laugh at their bewilderingly complicated effects; you may be puzzled at their efforts to explain what happens when a horse and its rider jump over a fence; but at least, they have a basic idea behind all their apparent madness. Now the futurists have been particularly struck with the possibilities that lie in scientific and engineering subjects. One of the best known of them, Miss Frances Simpson Stevens, has boldly attacked the problem of interpreting the modern power- house on canvas. To an artist of the older schools the power-house is simply an aggregation of engines, boilers and dyna- mos. He knows that the shafts of the machinery spin around at the rate of hundreds of revolutions a minute; but he makes little or no attempt to give you any idea of what these terrific speeds mean. To the futurist, the machin- ery itself is of no pictorial im- portance; the let-loose spirit of the great dynamos is everything. And so we find Miss Stevens ignoring mere masses as such and actually endeavoring to paint velocity. Let Miss Stevens speak for herself: “Here we are, Americans, living in the biggest and most powerful enormous inventions and stupend- method adequate to express the ARNON EERIE ery can be made into a harmonious, informal design. A futurist artist in Italy, seeing an ordinary street car go by, realizes the future possi- bilities of power and speed, and he begins to paint great trains going so fast that they lose their definite form in the lines of direction. Mo- of the material bodies. Even those artists who paint. mechanical forms have achieved nothing of the life, or force, or purpose of the object. The futurists make their engines move, throb and create. Something is pictures, and the great variety of color and changing lines helps to convey this impression.”’ . 538 ee ee city in the world, during a period of | ous activity. But there has been so_ far, no attempt in art to find a- vastness of-events to-day. Machin-~ tion and light destroy the solidity always happening in a futurist’s ~ re ae eo - pound! Popular Science Monthly If Beefsteak Is Too Dear, Try a Horse Porterhouse — of buying all the fine meat cuts, from roundsteak to porterhouse, at from six to fifteen cents a It can be done; itis being done. There are Ital- ians, Norwegians, Germans and Swiss in New York who are paying no more than fifteen cents a pound for the choicest steaks. And they are getting meat which for palatability and nutritive value is far above most of the beef tenderloins and sirloins we consume at the prevailing price of thirty-two and thirty- six cents a pound. It is not beef that these wise foreigners are eating, but horse meat. The very mention of horse flesh is unpleasant— not because one out of a thousand-knows what it tastes like, but because we love the horse and therefore dislike to eat him. Yet the horse is perhaps our cleanest ani- mal.- He eats clean food, lives in a clean environ- ment, and keeps himself clean. He is practically free from tuberculosis and many other serious diseases to which our flesh-producing animals are subject. Not- withstanding this, however, we continue to make beefsteak a staple food product, despite the exorbitant prices at which it is sold. os The one store in New York city, and the only one in the United States, which is selling horse flesh is doing business under the most favorable conditions. The horses are slaughtered under the supervision of veterinarians of the Department of Health and every precaution is taken to safeguard the consumer. Health inspectors are on hand to convince prospective purchasers of the food value and cleanliness of the meat. Indeed, everything is done to overcome the prejudice against it. To prevent deceptions, no-other meat may be sold under the same roof with horse meat. To sell it, a butcher must take out a special license. In France and in Germany © Int. Film Serv. Cutting up a quarter of horse flesh for two purchasers. The price ranges from six to fifteen cents a pound The only horseflesh store in the country. The Department of Health supervises the slaughtering and shops horse meat shops have been in business for years. Outside the French shop hangs a horse’s head as the trade sign. According to those who have eaten it, some knowing- ly and some unknowingly, horse flesh resembles beef in taste, only it is sweeter. The Military Dentist Is No Longer a Luxury But a Necessity Until the Canadian troops reached Eng- land with their well-equipped base hospi- tals and dental units, the British looked upon the military dentist. as a luxury. Now the military dentist is put on a par with the veterinary surgeon. Even in Australia, where the military authorities were slowest to appreciate the value of dental hygiene, army dentists are now doing a splendid work. According to a Melbourne paper, operations numbering twenty-five thousand have been performed, and more than ten thousand teeth have been saved. Warfare on Wheels What the United States is doing with armored automobiles RIFLE FIRE OPENING CRANK HANDLE TO START ENGINE FROM ( INSIDE —-- ~~: DRIVERS SIDE OPENING CHAIN TO FLY WHEEL HEADLIGHT GUARD Pa me r- HINGED TOP [ee FASTENED TO TURRET: RAPID FIRE GUN ON PIVOT REVOLVING TURRET x. ON CASTORS S. Gon 4 y, / | STEEL STRIP j “ie AMMUNITION STORAGE The first armored car built by the government. The chassis has a steering post at each end so that it may be run in either direction with equal facility. There are two turrets for machine guns RMORED motor car development in the United States has hardly passed beyond the experimental stage, as available funds have usually been needed for other purposes and the value of this weapon in the United States seemed some- what doubtful on account of the many poor roads. Only types actually tested or used by the War Department are shown with this article. Others have been built by patriotic citizens for National Guards organizations and by military schools and motor car companies. Some of these privately built cars are of real mili- tary value and others are for show pur- poses only, having ordi- nary steel walls instead of the treated armor plate necessary to resist bul- letsand lacking the equipment required for real service. Cet 0 Oe \ The type of light truck used by the National Guards on the Mexican border in lieu of the usual pack-mules 540 These are valuable. as ‘‘lesson cars.” The illustration above shows the first armored car built by the government. The chassis is a powerful machine, driving and steering on all four wheels and with a steering post at each end so that it will run in either direction with almost equal facility. There are two turrets for machine guns, so arranged that the guns may fire through the roof upon attacking aircraft if necessary. The armor covers all vital parts and will resist a service rifle bullet at one hundred -yards. The may be opened and closed and the car cranked mB from the interior. The weight. with ammuni- tion and sup- plies is about. twelve thou- sand pounds. and this weight, is the principal r ’ ee ee a eS a eS radiator door — ee Se — ce a ee SF ee a a ee ee objection to the type; for on soft or muddy roads the wheels may sink so that the axles rest on the ground and the car may stall, although the great power will still turn _the wheels. Another type is a lighter car built on a rear wheel drive, one and one-half ton truck, equipped with steel wheels -and airless tires and capable of running forty miles an hour. Having but one turret, the weight is reduced to about _ nine thousand pounds. It has not the power to maneuver on bad ground that the heavier car has, but is probably better fitted for all-round service in the United States. Still another type follows the lines of that just mentioned, but is built on a touring car chassis by a private company. The weight is about six thousand pounds. The “bridges” _ carried on each side for = crossing trenches form a : Oe vee he _ novel feature. There are a number of other features reflecting European exper- ¥ ience. Incase of war _ the majority of cars __ would probably be of _ the general type of this light high-speed car. The light truck shown at the bottom :of _ the preceding page is not in any sense an armored car, but is interesting as showing _ what was done to carry National Guards _ machine guns on the border. Each regi- _ ment was given five trucks in lieu of the _ pack mule equipment of the regulars. Four _ each carry one machine gun and ammuni- _ tion, and the fifth, spare parts and supplies. A ten-gallon water tank is carried under each body on account of the scarcity of _ water which the troops encountered in the _ border service. In action the trucks are. left under cover and the guns and ammuni- tion carried to the firing position by hand. The “‘caterpillar’”’ type tractor is beingex- tensively experimented with to replace horses for drawing the heavier field guns, each tractor doing the work of sixteen horses. As these tractors may come under fire, certain vital parts will be armored. More powerful tractors of this general type were doubtless the basis of the English ‘‘tanks,”’ A light-weight type of high speed for general service which has received high endorsement Popular Science Monthly 541 A model built on a touring car chassis by a private company but the little forty-five horse- power tractor shown in the photograph on the left is only expected to do light service, principally to transport ‘the army guns and ammuni- tion in record time wherever they may be needed and in spite of unfavorable road conditions. - How the Submarines Got Their Peculiar Names VERYONE knows what submarines are, and what an important factor they have become in modern naval warfare. Their nomenclature is. rather interesting. In the United States Navy the first of these crafts were named for various kinds of fish and reptiles, and we had such odd cognomens as ‘“Adder,”’ ‘‘Moccasin,’’ ‘‘Pike,’’ ‘“‘Stur- geon,”’ “Shark,” ‘‘Carp,”’ “‘Haddock,”’ etc., on the naval lists. Before this list of piscatorial names ran out the system was changed, and designations of A-1, A-2, B-1, B-2, etc., down to the more recent submarines au- thorized in 1915, known as the O class. In general, the numbers applied correspond to the particular lot in which they were constructed, and the letters closely follow the number of years since they were first built. In Germany they are all known as U-boats, the U being *the first letter of Unterseeboot, meaning submarine. : = ae | cr years ago Glen H. Curtiss launched into the air a new kind of craft, which he called a “flying boat.” Such a craft is much heavier than a land aeroplane. Naturally, Curtiss asked him- self: If a heavy motor-boat can fly, why should it not be possible to launch a heavy automobile S)\ The Flying Automobile Glen Curtiss builds a limousine in which you can take trips through the air By Carl Dienstbach bile which is to take you to some fashion- able tea. The body of the Curtiss limousine is remarkably well designed, from an aero- plane point of view. At the rear, the car body terminates in a knife edge. made it necessary to place the propeller behind the limousine, in the same manner as a slender poop is provided for the protec- tion of a steamer’s screws. It may be noted that the aero- into the air plane portion by means of of the craft is wings. very much like Although the triplane Curtiss was built by Curtiss — the first to recently — make a fly- for Ruth — ing boat, he Law and ~ was not the described in | first to con- the March ~ ceive or issue of the © EYER Uae = SHAFT HOUSING ON POPULAR - ry out the “FLOOR OF CAR SCIENCE idea of fly- MONTHLY. ~ ing in an The use | automobile. of an.auto- | About six i& mobile. years ago © hue. Press Assoc, body has q the French The lines of the automobile have been deliberately retained in spite solved at oil mag- of the tremendous downward pressure of windshield and motor hood one stroke © nate, Henri Deutsch de la Meurthe actually placed an order with the Blériot works for what he called an aero-taxicab. That name fitted it well. It looked like one as it flew in the air. It used to be supposed that triplanes would never do for fast flying because of the great head resistance which they offer. But resistance can be reduced by proper designing, and triplanes, as a result, are as fast as the biplanes of three or four years ago. A triplane ean be made strong and still light. That, no doubt, is the reason why Curtiss adopted it when he made up his mind to build a flying limousine. Look at Curtiss’ new machine, as it is revealed in the accompanying picture. What a contrast there must be between flying in this well-designed enclosed body and an open military machine! You step in, wearing your silk hat and afternoon clothes, just as you would into an automo- a knotty > mechanical problem. In the ordinary fly- ing machine, motors and propellers are directly connected. propeller shafts. extraordinarily large—by only a hundred- horsepower motor. Obviously, by slightly raising the limousine’s floor, a change-gear and a reversing gear might have been in- stalled as snugly as in an automobile. This would have made it possible to start and land on restricted areas. The front wheels of the machine are steered exactly as they are in an auto- so that the craft can run on mobile, unobstructed land for long distances. 542 This also- In the flying auto-— mobile, there is a reduction gear between ~ the motor and propeller—something quite new. This appears in the form of a shaft running back through the limousine and connected by. belts and pulleys with the ~ Thus, it becomes possible — to drive a 914-foot, four-bladed propeller— 5 tin TOO TTP ee SN a oe a. oe Se a sy oe E have, approximately, five thou- sand miles of coast line, about , three hundred miles of which are _ now protected by twenty-nine coast de- the first line of defense, coast defenses as the _ second line, and the army as the third. But no matter how strong a coast defense _ may be, if it cannot repel land attack as well _ as sea attack it is practically useless. Thus _ big guns are not alone sufficient; there must bea land force and smallarms. The latest official estimate places the number of our coast artillery at 508 officers and 19,278 - men. Obviously, this is far less than it should be. Furthermore, our guns are for the most part old models, hope- _ fenses. Military men regard the navy as’ Can We Protect Our Coasts? On the Atlantic seaboard a hostile army of 400,000 could land at 116 undefended points the firing were done by howitzers, the ammunition f ? would last about thirty minutes. Fortunately, this situation is no longer true, due to a re- awa- kening of the author- ities at Wash- ington to the - -real -state of affairs. Our am- munition supply has steadily increased since 1915. But it must still ’ be far behind the needs ; eral Wood says thatanenemy fleet could lie = _ The stars indicate the positions of forts Py along the Atlantic Coast. There are __-mo less than 116 undefended points i A eT. = * -_~ _ Rockaway and throw shells into Four- _ teenth Street, New York, we have. to swallow hard and admit he’s right. _ However, his statement is short-lived. ~The Government is now building a fortifica- tion at Far Rockaway, which, it is hoped, will protect New York from danger. But as regards Chesapeake Bay, one of our vulnerable points, nothing has’been done to protect it from the danger of foreign inva- sion beyond the placing of submarine nets. - So small was the supply of coast defense ammunition in 1915 that it would be exhausted in forty-five minutes by a “hs _ Capacity fire of our coast defense guns. If. of the hour. . Our own army offi- cers have pointed out to us that 400,000 men could easily be landed on the Atlantic Coast. A system of heavy guns permanently mounted on railway carriages— mobile forts, in other words—has been suggested as a means of protect- ing our coast area and inland cities. They might prove useful, when it is considered that there are no less than one hundred and sixteen undefended points where-an enemy could place troops. These statements ae are alarming. About the only redeeming feature of our situation is to be found in our railroads. We have a valuable net of railroads which could transport troops quickly. In spite of the despairing predictions made by our military authorities, one of which is that it will be years before our coast defenses and mobile army can be developed into real fighting units, there is the hope that some agency—motor torpedo boats, coast submarines, mobile forts, or whatnot—may back up our ‘coast fortifications and afford our coast line the protection it needs. | 543 How Our Naval Officers Play at Battle In the naval war game all the world’s at war and all the men merely officers and fighters One of the players is receiving an order. heavily against his side. HE game-board on which our naval | officers fight out imaginary naval battles based on a problem with which they would be confronted in real war is a low table which represents a section of the sea. It is divided into small squares. The pawns in the*game are small leaden vessels that represent in outline the differ- ent classes of warships. When the problem is first assigned, the players, who are usually experts at the Navy War College, Newport, R. I., are divided into two sides. Each has its Commander-in-Chief, who is assisted by a staff just as he would be in war. The game-begins on a chart. When the scouts report ‘‘Contact with the enemy” the problem is transferred to the game- board, on which the supposed engagement is fought out to its smallest detail. Fuel supply, casualties, wind and weather figure in this theoretical battle. The ships are moved on written orders which may be either radio or flag signals. In the illustration one of the players is receiving an order, and on his decision rests On his decision rests a move which if faulty will score The table on which the game is played represents the sea a move, which, if faulty, will score heavily against his side. The track of each ship,’as it moves across the squares, is marked by chalk to show its position at any time of the twenty-four-hour fight staged on the board. — The tracks help in working out the torpedo — runs so that effect of torpedo fire may be plotted. } When the fleets come in effective range, say at 14,000 yards, fire is opened. The effect of the fire is marked by a card system — on the blackboard in rear of the players. Actual war conditions are thus simulated. — A ship damaged fifty per cent, for instance, — is marked down in loss of speed and maneu- — vering ability. ; The importance of approach to battle is driven home; for a slight initial error may turn out to be the pivotal point in the fight. The game-board trains officers to make quick and accurate surveys. Delays in making the right move-spell disaster. — Maneuvering for the best position to be ready when fire action opens is another point on which stress is laid. Every detail — 544 expats eee Se if ra ” Mihi. ie Popular Science Monthly . of the great Jutland Battle has been fought out on this game-board. — On the board the home fleet is shown by light-colored ships, and the enemy’s by dark-colored ones. When the game begins on the board the scouts areshown in contact. Behind theirscreen the supporting ships close up, and behind them the big battleships maneuver for the opening of fire action. The war game as practiced now by all armies and navies was first devised by Von Moltke, who, when elevated to the post of Chief of Staff in 1857, introduced it into the German army. The United States army works out its problems on maps scaled twelve inches to the mile, at the Leavenworth Army School of the Line. The Coast Artillery has its own game, in which the advance of a hostile fleet is opposed by mines and gun fire. The artillerists are taught to identify at a glance every type of foreign vessel. Stopping the Automobile with a Vacuum Brake NEW brake has been invented for automobiles—a vacuum brake, which, as its name implies, operates not by the force of compressed air but by means of a vacuum created by the engine. The mechanism of the new device yqye consists of a cylinder containing a ON INTAKE L piston faced with leather, a lever that connects with the brake rod, a small controlling valve and sufficient copper faniroin By MOIOR tubing to connect the eee crniee IN intake manifold with waive open, pRanes/ the valve and the. ™ , vacuum cylinder. When the engine is in operation a vacuum is created within the in- take manifold which amounts to a suction of about ten pounds to the Square inch. This suction is employed to move for- ward the piston in the cylinder. By leverage this suction pull may be de- veloped to a thousand pounds pressure at the rear wheels. The pressure of a finger on a lever at the steer- AIR DRAWN TO INTAKE & OPERATING ROD A , INE Sf 545 The vacuum brake with its thousand pounds pressure serves to counteract any inequality of brake adjustment. Thus if one brake requires three hundred pounds pressure to make it effective, while the other responds to not less than five hundred pounds pressure, it will be evident that one thousand pounds applied between them will be ample for both. This makes brake operation more certain and is an important safety factor. The engine must be running in order to make the vacuum brake operative, but the very slowest movement of the motor is sufficient to get results. Even with the gear lever in neutral and the engine at rest, the application of the electric starter is sufficient, or the cranking of the engine by hand will accomplish the same result. A slight leak in the copper tubing will not interfere with the action of the vacuum brake. While acting as a service brake, this new “self-starter’’ is not designed to replace the hand or emergency brake which holds the car on a grade while the engine is idle. The cylinder is only four inches long and has a diameter of seven and three-eighths inches. It is braced in position by attaching it to cross members of the frame. The controlling valve may be attached to the lower part of the dash or the engine base. ~! y 2 . Sj > f AIR FROM ATMOS- PHERE TO VACUUM Pitag DER. BRAKES wy QR AIR CANNOT HEA SPRING COMPRESSED ENTER S q ae | ; = ing post is sufficient to apply this tremendous force to the brakes. When the engine is in operation a vacuum is created within the intake manifold which amounts to a suction pull of ten pounds to the square inch. This is magnified by leverage : The Terror of the Sea How submarines are driven and submerged; the difficulty of building them very big; the folly of the one-man submarine SUBMARINE is a maze of machin- A ery. Unlike any other ship she has two sets of driving engines—one oil and the other electric—and she is built with the nicest regard for weight. First let us say something about the engines. They are the most important part of the boat. At first gasoline engines, like those used on automobiles and motor-boats, were in- stalled in submarines. ~The Germans had them in some of the submarines that they used in the beginning of the war. We, too, used them. But as the gasoline engine was made bigger to meet the demand for in- creased power and‘speed it literally. broke down. The Diesel engine must be used. It was invented by Rudolf Diesel, a German engineer, while -he was still a student. ~ ath : In the Diesel engine air is sucked into th cylinder and subjected to such pressure by: « the piston that it becomes intensely hot. Then a little oil is squirted in. At once the oil-vapor ignites and the mixture of oil- vapor and highly compressed air expands with explosive suddenness. The Diesel is the most efficient type of engine ever in- vented, utilizing as it does about thirty per cent of the energy in the fuel as con- trasted with only thirteen per cent in the best steam-éngines. But it also uses air. In other words it bréathes. When a sub- marine is under water the crew must keep alive by breathing what air they can obtain from tanks. They have enough for not more than thirty-six hours. So, it becomes necessary to equip a sub- marine with electric motors, fed by storage batteries. As soon as a submarine dives, the breathing Diesel engine is cut out and the electric motor switched in. Down in a Submarine Like the policeman’s in Gilbert’s song, the life of a submarine sailorman is not a happy one. The quarters are necessarily so cramped that it is difficult to provide ordinary ship comforts. The officers have cots and the crew hammocks for sleeping. In our new boats ice-boxes are provided, so that fresh meat and vegetables can be * shaking of the boat. ‘ The regular purring of the motors is heard. We are served. In addition there is a dry food supply sufficient for five days. At sea the crew is put on a daily fresh water allowance. To bathe, the men must jump over the side. Even when the boat is running on the surface the ventilation is poor. The pro- prietor of a New York sweatshop who did not provide his workmen with any more air than the men in a submarine breathe would be arrested. When the boat is sub- merged, the’nauseating oil odor, the battery fumes, the vitiated air exhaled from a score of lungs make one wonder why everyone is not sick. As a matter of fact seasickness, produced by these conditions, is common enough. bem What is the scene within a submarine when an attack is made? A German officer of the U-26 gave this account of an attack on an unnamed British warship: “The boat is cleared for action. The flagpole is taken down. Part of the bridge is folded up and lashed. The periscope is elevated. The hatch through the combined, bridge and conning tower is tightly closed. The motors cease their endless song. Fromsnow on electricity will drive us until we rise to the surface again. peeks “‘A young lieutenant is posted at the periscope and looks for the enemy. The sailors take their position near the torpedoes. The interior of the boat is lighted with two small electric bulbs. They do not clear the gloom. Everywhere is the smell of stale oil. It is impossible to speak with the din of the machinery and of the inrushing water. te “From time to time the officer in command of the torpedoes looks at his watch, which he wears on his wrist, or at his compass. Intently the men all watch a signal board in front of them on the side of the boat. . . . Suddenly we start and forget the heat, the foul air, the discomfort.. In small luminous letters the word ‘Attention’ flashes up on the board. The commanding officer grasps the lever which will release the first torpedo. The men prepare to launch the second as soon as the first is discharged. Half a second later and the red letters on the board say ‘Fire!’ The lever is jerked, and the torpedo leaps out. There is a short metallic click and the noise of the water rushing into the empty tube. The second torpedo is at once inserted. A few seconds later and the interior of the submarine looks as before the attack began. “But what of the first torpedo? We hear only the noise of the motors. We wait. Nothing happens. Then suddenly we are all thrown in a heap by the Then the boat rolls as before. on our way home. The attack succeeded.”. 546 Hi lcs i laa acai SL a ee SE a! ae SR a ee ee at eC re The Mine-Layer Lays Mines As If They Were Eggs / SS WIRELESS AERIAL _ TELESCOPING MAST—4 BINNACLE rt es ON DECK FOR EXHIBITION ‘ | | | _ DETONATORS | [Ss LWALVE FROM WHICH | SAFETY PIN HAS | AUTOMATICALLY BEEN IWITHORAWN REN= |DERING DETONATORS, | iACTIVE —, 2 mine risinc + 2 Se eT Ts as <== ‘a ~ see ae name f ff : x MINE SUPPORT DRUM | ; SINKER / —_— The German mine-layer is a new and ingenious type. It carries no guns or torpedoes—nothing but mines confined in twos in inclined tubes at the bow. The mine itself (insert) has a sinker which carries it down to the bottom, where hinged legs are forced out and lie flat on the ocean bed. By means of a hydrostatic valve the mine is enabled to remain at the right dead level 548 Popular Science Monthly © Int. As this vivid description indicates, a sub- marine is submerged by letting sea water flow into tanks. A submarine has two kinds of tanks—one for ballast, the other for trimming. The trimming tanks, used to trim the boat fore and aft, are in the bow and the stern; the ballast tanks at the bottom and sides. The torpedo tubes are usually in the bow of the boat, although there may also be tubes in the stern and even in the side as in some for- eign boats. Let Lieutenant C. N. Hinkamp of our Navy tell us how the boat is handled: “The actual submerging of the boat can be done in two ways, one called the ‘static’ dive; the other the ‘running dive.’ In the static dive, also known as ‘balancing,’ the boat is submerged, but does not move except in the vertical plane. This dive can be accomplished in two ways; by trimming the boat and maintaining her trim by adjusting the ballast, or by dropping the anchor, trimming the boat to within a few hundred pounds positive buoyancy, and then heaving in or veering on the anchor cable. “The mass of a submarine itself amounts to several hundred tons, but the actual forces used to sink it from a neutral state are very small. The addition of 50 pounds of water will cause the boat slowly to descend. “The static dive by adjustment of ballast is made as follows: After getting the fore and aft trim. . the main ballast tanks are flooded through large Every member of the crew knows exactly what he must do; not only that, but he knows, as a rule, the duties of every other man. This means team work valves, the operation requiring from one to two minutes. . . The boat being trimmed down as far as the main deck, still has too much buoyancy to run submerged. The tank next flooded is the auxiliary ballast tank. This holds enough water to destroy the remaining buoyancy. ... The final trimming is done by slowly filling the adjusting tank. When the vessel is trimmed until there is about two or three hundred pounds of positive buoyancy, it can be readily handled submerged. This is considered the best trim for all around work and completes the static dive. From this condition any operation sub- merged can be commenced. To beable to determine when to stop is almost the entire secret of the art of balancing. “The running dive is made from the awash con- dition. In the awash condition the trimming tanks and auxiliary ballast tanks are flooded to the amount necessary for the proper trim when submerged; the main ballast tanks are empty. The vessel being underway ‘awash,’ the order is given to submerge. All hands get into the boat, the engines are stopped and the electric motors are started. As soon as the engines are stopped the conning tower is closed, all ventilators are housed, and the main ballast tank is flooded. . The boat is inclined slightly, about one half a degree down by the head, and the inrush of the water controlled by manipulation of the valves. All this is done in the short period of from one to two minutes.” A submarine may run submerged with only her periscope sticking out above the water. Then she can see all about her eee ————— — Popular Science Monthly plainly enough. When even_the periscope will betray her, which it does partly on account of its wake, she must dive com- pletely and become absolutely blind. Hence, .the periscope has been fittingly called the “eye” of the submarine. It isa telescope built so that you can see around a corner or over a wall of earth or eeecetinl one sees in look- ing through the periscope “eye” of a United States submarine The commander of a submarine looking through @ periscope at the outside world from under-sea 549 “A number of one-man submarines have been built, but they have never proven to be of much value because they had such a short radius of action and low speed. The modern Whitehead. torpedo is something over 18 feet in length and 18 inches in diameter, and it requires a good sized vessel to carry one of these within the hull. If carried outside the hull, which has been done in some cases, the torpedo offers much additional resistance to a small craft and thus tends further to reduce its speed. “We prepared a number of one-man boats, which our engineers designate ‘pickle-boats,’ but they were very disappointing as to the speed it was possible to get out of them.” This was not written of the Ford plan, but on the subject in general. Ford’s idea of building one-man boats very cheaply is ridiculed by naval men. The engine necessary to obtain high speed would have to be as light as an aeroplane motor, and aeroplane motors cost about $5,000 each. Thomas Orchard Lisle, a prominent marine engi- neer, punctures the Ford idea very effectively when he points out what are its limitations: “Mr. Ford proposes to drive this submarine with the same engine that is used in his automobiles, of which, I believe the maximum horse- power is forty under the best conditions. This would give a small boat, say twenty feet long, a submerged speed of not more than eight knots; that is if an internal combus- tion engine could run when the boat is submerged. So x © Underwood and Underwood, N. Y. water. There are as many kinds of per- iscopes, almost, as there are styles in hats. Each boat in all navies carries at least two periscopes, one for the commanding officer and one for the helmsman or second officer. The One-Man Submarine Henry Ford’s proposal to build cheap one-man submarines has once more focused attention on an idea that has always fas- cinated inventors. But no one who is at all familiar with submarines believes in the one-man type. Ina letter to the POPULAR SCIENCE MONTHLY, Simon Lake, our fore- most submarine inventor, disposes of the question in this fashion: imagine the futility of chas- ing a _ thirty-knot battle cruiser with an eight-knot submarine.” Mr. Ford has not considered among other things, the difficulty of supplying air to the engine and to the solitary constituent of the crew, nor the disposal of the exhaust gases, so that they may not betray the boat in a soda-water wake, nor the utter impossi- bility of operating such a boat in a rough sea. In their mine-layers the Germans have developed a new and ingenious type of sub- marine. One of the mine-layers was cap- tured by the British last year, and the details of her construction have been given out by her captors. She is about 110 feet long, and 11 feet beam, and she displaces i a dn pexard sq p11 Aoyy osaym suey diysuresys & PIEMO}Z JO PUL] PIEMO} Udy} MOz O37 ‘s}BOqosI] 34} OF 41 MOI} 03 s}o9dx5 AjjueptaAs ‘puey ut sdoxz ‘soyTes suLreuiqns aYL “pesseyosip st opad1o3 A[peap ay} 210jaq MoJD pue sioSuassed STY SARS PUL $}BOqd}T] SIY UW 0} urleyded Joy 0} poTeUsis us0q aaey SJapso pue drys ysysuq ue poddos sey ourewqns S4L “SHI UeUlIay psze1q29]99 ay} “IaMo3g ATI Aq PeATs0UD sB oIejJeM sUTTeUIGNG ,,,, © ine Yl 550 Held Up By a Subma of a chain. after the sinker _ of the mine above nia still rules the _ marine has unques- - more cautious. The Popular Science Monthly about 200 tons. In other words she is not more than one third as big as an ordinary sea-going, commerce-destroying German submarine. A mine-l. carries no.guns or torpedoes —nothing but mines confined in twos in inclined tubes at the bow. The mines are released from the conning-tower. Each mine has a sinker which carries it swiftly down away from the. 551 others boldly advocate the fleet submarine, even though no one knows how -to obtain the engines to drive it, others recommend a comparatively small coast-defence type. In view of our present conflict with Germany,every American wonderswhat we would do. if the British fleet were not engaged in corking up their German dread- noughts? Considering our two enormous coast lines, our pos- submarine. As the |® e: see mine sinks, hinged [| — Re stb legs are forced out by springs, the legs lying flat on the bot- _ tomofthesea. The_ mine itself is at-~ tached to the sinker or anchor by means Soon strikes the bottom the mine floats up. .|7 _A device ‘called’ a | _ hydrostatic valve regulates the height — the anchor, so that whether it be high __ or low tide the mine __ will always be at the right dead level. Although Britan- ‘Waves quite as com- pletely as she did in _ the days of Drake and Nelson, the sub- _ tionably made her ex sessions in Alaska, the Philippines and the Hawaiian Is- lands, some of our officers think that we need not only coast defence sub- marines (the 800-ton type with a surface speed of 17 knots, able to remain at sea for three weeks) but something much more formidable. Thus, Captain W.L. Rogers agrees that if our main fleet is destroyed, coast de- fence submarines cannot prevent an enemy from landing, because they cannot know when and where an attack will be made, and they cannot escape drags and nets forever. What we need, ac- cording to him, are fleet submarines— © Int. under water. _ English Grand Fleet emerges only when __ it has a prospect of fighting, and then only _ when it is preceded by a cordon of torpedo boat destroyers, which keep an eye out for an submarines, and a squadron of ‘hap mine-sweepers and trawlers which fish out _ mines planted by submarine mine layers _ and which net any submerged submarine in _ the course. When the battle fleet is safely out in the open sea it must keep moving. _ The blockading squadron, too, must not _ venture too close to German shores, and it, too, must move always. Naval officers are by no means agreed what type of submarine the United States should adopt. While some pin their faith to the big, German sea-going type and An aeroplane can detect a submarine It is, therefore, one of the most formidable of enemies vessels which will be able to keep at sea with scouts and bat- tleships, which will have a surface speed of at least twenty-five knots. This problem of building a submarine which is able to keep pace with a fleet of battleships and battle cruisers, is so difficult of solution that some naval authorities despair of seeing it solved at all. At present no submarine, even of 1200 or 1500 tons, can be equipped with sufficiently powerful machinery to make the required twenty-five knots necessary to keep up with a battle-ship squadron. On the other hand, small. submarines cannot act for months at a time with the main fleet per- haps a thousand miles from a base. They have neither the speed nor the endurance. Liberty’s Improved Torch Three tones of tinted glass were substi- tuted for six hundred square feet of bronze ” To cut out pieces of the bronze plating in this long protruding flame, one man lay flat on his back a fellow workman. It was a six days’ job NE of the most impressive fea- tures of the Statue of Liberty as it illumines the night is the flaming torch uplifted high above New York harbor. Few who watch the torch’s symbolic flickering light know the story of its recent im- provement—know, indeed, how the workmen, oftentimes lying flat on their backs with no scaffolding or underpinning to support them, clung to the framing and drilled thousands of holes for glass plates. which took the place of the old bronze covering. A false movement meant a fall of more than twenty feet and a slip and slide down the interior of Lib- erty’s arm. Besides there was the constant swaying of the torch and arm during high winds to be reckoned with. But these dangers did not dam- pen the ardor of the glazers and they finished their work on time. To-day Liberty’s torch is not of dull bronze but of shimmering glass, as Bartholdi, in the judgment of Gutzon Borg- lum, the sculptor,*~wished it. to be. Situated three hundred and fifty feet from the upper terrace, the torch is reached only by a sixty-foot ladder which starts from a small plat- form at the shoulder and . runs up. the arm to Liberty’s hand. A this point a six-foot vertical ladder leads to a two-foot gallery running around the base of the flame. upheld by .. days the torch twists and shakes. The first work was the removing of the crude steelwork and the substitution of sheet bronze, as described in the PopULAR SCIENCE MonrTaty for February. Follow- ing this, yellow glasses of various tones were selected and graduated from the bottom up in deepening shades. On windy Hence the ordinary method of glazing could not be employed. A new method had to be devised—and without delay. Pieces of the’ bronze plating were cut out from the inside of the torch, and molds were constructed from them upon which the glass was bent. The greatest difficulty was experienced in reaching the extreme points of the torch. The one long pro- truding flame, which is shown above, had to be cut open by a man lying flat on his back and held by another during the work. It took two men six days to cut this one section. ‘ around each opening and brass bolts were threaded through them. Over BRONZE The glass is embedded in soft putty and kept rigidly - taut by spring tension Miss Liberty’s torch is no longer of dull, inert bronze but of shimmering glass the bolt ends was placed a small clip spring. The glass was given an edging of non- hardening putty; another clip spring was slipped over the bolt end, and the nut was oO Holes were punched in the ribs . too wpe pe RNS ae el Popular Science Monthly screwed home. Bedded thus in soft putty and kept taut by the spring tension, it is impossible for the glass to 553 studios, which is situated on the top of a glass-covered fireproof building, a gigantic overhead lighting system break, even under the severest strain imposed by snow, ice, rain, or heat. Inside the torch are fif- teen five-hundred candle- power incandescent lamps connected with a flasher (a flasher is a rotating drum with surface projections which close the lamp cir- cuits every time they hit a stationary piece of metal) to carry out the unsteady flicker and blaze of the burning torch. The torch also contains a lighthouse lens, _ nine and one _half -. inches in diameter and fifteen inches deep. costing fifty thousand dol- lars was recently installed. The -system comprises twenty-five overhead units of mercury-arcs. These units run en five tracks; with eleven contact spaces to each track, indicated:by white paint. By shifting a unit a few inches either way light is obtained for the deepest sets. The steel tracks sup- porting the overhead lights are nine feet apart and one hundred and seventy feet long. In-addition to this overhead system the gen- eral lighting equipment of the studio is supplemented Super-Daylight for the There are fifteen of these five- hundred candlepower lamps in- side the torch of the:-.Statue by another battery of floor lights. When all the lights ——— ee Motion-Picture Man NLY those who have visited a motion- picture studio and have watched the actors rehearsing under a+ battery of mercury-arcs, can realize the important relation of light to the successful photo- graphing of an indoor stage scene, or, as the motion-picture folk call it, a ‘‘set.” There is not only lavish, blinding light, but sweltering heat; for the lamps are veritable furnaces. In one of the New York motion-picture are going at one time, “super-daylight,’”’ according to the enthusi- astic and imaginative director, is obtained. When a play is being rehearsed an auto- matic switch enables the director to turn off the big batteries and substitute in their place incandescent bulbs. In the studio in which this vast lighting equipment is em- ployed five directors can photograph as many sets at the same time. The stage is seventy feet wide and one hundred and seventy feet long. Close-up view of the portable contact and carrying device. trolley feeders are indicated by white paint. mercury-arcs which run on five tracks, with eleven contact spaces allotted to each track Contact spaces in the There are twenty-five overhead units of New York State Protects Her Strategic Points and = a lea | ee ie ©,Ame.. Press Assoc. One of the New York Naval Militia boys guarding the entrance to Wil- liamsburg bridge. The entire Militia was called out as well as the National Guard and ten thousand policem:n Below: Building a fence around an arsenal to protect it in the event of an armed conflict. The work was done in remarkably quick time by a large force of carpenters under the supervision of militiamen © Int. Film Serv. An American girl turns out shrapnel in a New York plant. She and twenty other young girls volunteered their ‘services The first day’s duty. Bridges and public buildings have to be guarded in the face of a blinding snowstorm © Amer. Press Assoc. America Preparesas the War Scare Crosses the Atlantic a ee el an a All - public buildings, water - works, — bridges and strategic points in New York-State were - Vigilantly guarded when word went forth that our Government had broken with Ger- many. In the photo- graph above sentries are questioning a man Bayonet drill at the Lake Bluff, Illinois, camp is part of the rou- tine through © Amenecan Press Assoc The armored car with which New York’s home defense league is equipped... The car can be used in breaking up riots and dispersing mobs, as well as guard- ing public stores and charging an enemy. It is manned by a trained staff of army operators © Int. Film Serv. which western lads are put be- fore they become full-fledged bluejackets A member of the American Red Cross Society Preparing bandages Members of our flying corps studying a model aero- plane in order to become familiar with its operation The Motor-Truck Sewer Cleaner It does the work of four gangs of four men each CLEAR WATER COMPART MENT BAFFLE PLATES SEPARATE WATER FROM SEDIMENT FEEDS PUMP NOTCH/4 HYDRAULIC KOIST = mee FOR DUMPING ore g MIXTURE, DISCHARGED 0 BODY \ es _GENTRIEUGAL PUMP DRIVEN v Sy | STELESCOP- Me. Lee “ia MOTOR Se PiPe> SILENT "ioe pe Many’ oe adi OVERFLOW TO © SEWER OVERFLOW PIPE ie 4 To FLUSH Bea el UBSTITUTING mechanical power for hand labor, the ingenuity of a Spring- field, Ohio, engineer has found a way to clean sewer catchbasins by motor power. Not only does the machine do the work better than it was done by hand, but it does it more cheaply. The apparatus will clean from forty to fifty catchbasins a day, an equivalent to the work done by four gangs of four men each in the same time. The machine is a self-contained unit con- sisting of a five-ton motor-truck equipped with a pumping device. The latter is driven by the vehicle motor and draws the catch- basin sediment up and into the truck body by means of suction. After the body is full, the truck runs to the dump, deposits its load through tilting the body by means of a hydraulic hoist and is back on the job in less than half the time it would take a horse and wagon to make one-half the round trip. The apparatus consists of a watertight steel box body, an ordinary centrifugal pump driven from the vehicle driveshaft by means of a silent chain, and a device called the eductor which i is lowered into the bottom of the catchbasin at the end of a long telescoping pipe, as shown in the accompanying illustration. The machine consists of a > five-ton motor-truck with a pumping device which draws the catch basin sediment up and into the truck by suction WATER AND SEDIMi = UP FROM es bee Hig ve: SAFFLE = SAFFLE == RUBBER EDUCTOR PIPE._ PLATES PLATE HINGE GASKET, OVERFLOW J PIPE “at —p— RUBBER GASKET: S the pump to suck up the sediment. © This division is made by means of a steel plate parallel with one side and a perforated cross plate at the rear, forming an L-shaped tank for the water. The water is fed from the bottom of the tank into the centrifugal pump directly aft of the driver’s seat. The pump forces the water down into the catchbasin in a hose and up again through the eductor pipe. nozzle it sucks up with it the sediment in the basin. The sediment and the water travel through a bend in the top of the pipe and drop into the front end of the truck-body. The sediment falls to. the bottom and the water is made to pass through notches cut in opposite sides of three hinged baffle- plates. through the small perforations in the rear cross-plate into the water tank. At this time the water is practically clear. It is fed to the pump and used over and } over again until the truck-body is full of the catchbasin silt. An overflow valve and hose are provided to flush out the bottom of the basin after all the sediment has been removed. ; 556 The body is divided into two main parts, one for the sediment and one for the water used in As it passes the eductor — It passes to the rear and then™ oy ea 4 : = — 7. =m 2 a : , > 4 _ coupled to eight long passenger cars, as in _ powder as a fire extinguisher. _ Water is said to be far more effective than dry powder. _ pound of dry powder used. = j Popular Science Monthly -_ Water Proves to be a Better Fire Extinguisher Than Dry Powder RY powder fire extin- guishers, according to recent analyses made for the - British Government, contain as their main constituent, bi- carbonate of soda. Though this chemical gives off a cer- tain quantity of carbon diox- ide when heated, the investi- gating committee doubts whether it has an effective influence on the action of the “An experiment proved that: approximately one cubic foot of gas is formed for each How a Giant Redwood Compares with a Locomotive and Train GIANT redwood, uprooted and lying prone alongside a railroad engine the illustration below, gives a better idea of the immensity of these huge trees than _ any statement of length or diameter in : aa The redwood is in the vegetable _ world what the elephant is compared to - land animals or the whale compared to the tier denizens of the deep. Probably the tallest of these big trees is _ the Columbia, 294 feet—a hundred yards. _ Pace off one hundred yards and see what _ you think of it for the length of a log, and then if you were thinking of sawing or chopping this log, remember that you _ would have to climb up a ladder and start chopping at a height of thirty feet from the ground, that is, in order to make a cut above the stump of the tree. ; These great trees should, in reality, be extinct. But, like the elephant, they continue to live on in an age when their contem- poOraries are studied only in the form of fos- sil remains. It is almost im- possible to esti- mate their age. eight-car A redwood tree uprooted and lying prone beside an passenger train for The see-saw swing is operated by simply turning a hand- wheel located in front of the occupants of the chairs A See-Saw Swing Which Children Can Safely Operate LARGE swing which children can safely operate has been devised by Edward Hardy, of Blandinsville, Illinois. There is a long cross-beam supported from a high standard. A swinging chair is sus- pended at each end. Located in front of the occupants of the swing is a handwheel. Turn this handwheel and the swing is operated. Turning the handwheel winds up the cable over the rod with which the handwheel is connected by a series of gears. A downward pull on the free end of the cable causes the swing chair to move inward on the see-saw frame toward the central standard so that one end of the swing becomes lighter than the other and goes up. It is not neces- _sary for the occu- pants of. the seats to be of equal ag- gregate weight, as the shifting of the chair makes ms up for any differ- ence. A_ hz If - dozen children can be safely amused for hours by means of this clever contri- vance. size comparison Housekeeping Made Easy A foot control enables the operator of the motor-driven sewing machine ‘to stop or turn-on the current as de- sired by pushing a pedal down or up A combined pan cleaner and scraper. The scraper is of steel and the cleaner of cloth or broom’ bristles A table which has an invisible com- partment directly under its top for storing away the extra leaves Separating the cream from the milk with a simple dif disk and wire device A clothes rack attached to the head or foot of the bedpost can be adjusted to any position Hello Billt A unique bill file in the form of a defensive cat with the tail sharp- ened to a point at the end to receive the bills. 558 = asl hn * = as a me 7 rey ‘ cee aN ea ge eee a ee ey ne Above: | Pasquale Amato, the operatic baritone, talking into a telephone that to all appear- ances is a paper doll Housekeeping Made Easy A device for lighting the gas- stove through an opening in the burner plate. In this way the flare or “popping” is eliminated A candlestick for hall or living room. It has three adjustable candle supports. The standard is made of solid mahogany With this device a needle bath and massage can be given at the same time. The water is contained in the cylinder on the wall and comes through the brush in the form of a needle spray The “‘porron’”’ used by the Spanish peasants for wine, makes a quaint ad- “9 dition to the salad ~ equipment. Either coma Of the spouts may | be used for a handle A scrubbing-car knee-rest which protects the scrub- ber’s knees and clothing and saves time in moving along the floor. It slides along as if on casters A washtub with a built-in bn —h YS (al = athena =< : SS | == washboard and a station- (el (heer 4 ti ary container for the sdap An electric water purifier will prove a boon for the which is placed immediately small apartment. When in the water and the covered it has the .ap- sterilizing current turned on pearance of a small table 560 The little trolley boat has solved the problem of preventing canal ice from accumulating Trolley Cars on the Water? Yes; and in New York State T seems reasonable to conclude that if the electric trolley boat illustrated were in- troduced into Am- sterdam or Venice, it WAtL SEPARATING INTAKE AND EXHAUST MANIFOLDS / MANIFOLD Popular Science Monthly Increasing the Power of Automobile Engines with Mufflers REATER power is secured from an automobile engine if the exhaust gases are completely rather than partially re- moved from the cylinders just before each power stroke. While this can be accom- plished if'the motor has but one cylinder it is more difficult when two or more cylinders are employed, for the reason that two or more cylinders are connected through the exhaust manifold. This is due to the over- lapping periods during which the exhaust valves are kept open. E Under such conditions, the resistance or back pressure caused by the gases forced to pass through a muffler tends to make the pressure of the beginning exhaust hold back the gases in the cylinder from which the exhaust is nearly completed. This decreases the volume of new fuel gas and lessens the power from its explosion. These conditions have been largely over- come by the invention of an Indiana engineer, in which a number of mufflers are employed. In the case of the six-cylinder motor shown in the accompanying sketches ~ two mufflers are used. Each is connected with three cylinders so that successively exhausting cylinders operate through dif- ferent manifolds instead of the same one. By this means, only one exhaust valve is open at a time. EXHAUST COURSE OF . MANIFOLD CXHAUST GAS EXHAUST OUT would soon develop into a practical and popular “‘jitney boat.” The craft shown is by no means an ex- @¢f/ periment, but was de- = #*~Tomurricr signed to break up ice jams and prevent them from clogging the intake canal of one of the great power companies of Niagara Falls. The ice problem has always worried the water power. enterprises at Niagara. Large cakes enter the canal from the Great Lakes. To prevent these from accumulating near the power houses, where they would immediately check the flow of water neces- sary for operation, the boat is used. The hull of the boat greatly resembles that of a submarine as it is made entirely of steel. Although the craft is only eighteen feet long, it carries a seventy-five horse- power motor which gives it unusual power to buck the huge ice cakes out of the way. BOLT |e R BE EEEEI ET INCOMING __ FUEL GAS SEPARATING WALL INTAKE MANIFOLD Each of the mufflers is connected with three cylinders so that successively exhausting cylinders discharge through separate manifolds — ie ee ee & € . E a 4 ze a #, ’ Ps Teaching Our Soldiers How to Fight Problems in minor tactics are worked out in models of mud Above: A squad under instruction. the right, embankments. AND table work is acknowledged to be one of the most important means of instruction in military science. Work on the sand table has been done for many years, but First Lieutenant J. J. Fulmer, of _the First Disciplinary Battalion of the United States Disciplinary Barracks, Fort _ Leavenworth, Kansas, has introduced into _ the work scientific exactness. The sand tables used are ten feet long, four feet wide and three and one-half feet high to top of box, and the box is eight “inches deep. Sand is put in the box to a depth of six inches. It is well watered with _ an ordinary watering can. : : Two sets of implements are used. One is known as the fortification set and the other Those on the left are making a simple trench and those on At right: Tools and supplies for making fortifications and relief-maps as the terrain set. The fortification set contains eight gabions (round, bottomless baskets, filled with earth), four fascines (bundles of sticks bound together) four hurdles, twenty bags for sand, one box of blocks, representing sod, and one bundle abatis (obstacle composed of felled trees). Besides these there are trench models and material to represent hills, woods, streams, railroads, bridges, concrete, king post, A portion of country as laid out on the sand table, showing rail- roads, hills, jtown, woods, etc. 562 eosegile. Science Monthly ‘ Embankments and obstacles. Reading from left to right, fascines (sticks bound together), gabions (bottomless baskets filled with earth), hurdles and sand-bags From left to ie sand-bags, sod and plank embankments, military pits, abatis (pointed obstacles), wire entanglements and wire fence with apron on each side Samples of trenches, showing simple trench, enlarged trench, trench with": traverse . sections, communicating trenches and trenches with individual eas positions ; } q ; q 3 j ' 4 ‘ Rear view of a portion of field fortifications Front view of the same. Note abatis, wire q of different kinds made on ‘the sand table entanglements, wire fence and_ shelter ‘ . : . _ queen post, pontoon, railroad trestle, one railroad markers, one leveling roller, one ~ train, railroad, water tank and about fifty. folding rule and one trowel. Work with — buildings, as well as glass for representing _ the terrain set gives the soldier a fair idea of © j bodies of water. This set teaches map- a big military problem and of his personal ~ reading and contours, and with it it is possible to do work in outposts, scouting and other problems in minor tactics, far more satisfactorily than on the map. The terrain set contains a section of wire fence, a section of wire loops, a section of high wire entanglement, a section of low wire entanglement, a section of chevaux de frise (spiked obstacle) and a form for fire trench with attachment for enlarging. This set also has the following tools: one surface float, two road markers, two importance in it. It does not restrict him ~ to the small section of ground he would see ~ while actually engaged in his duty. On the sand table he is enabled to work out his own route in patroling or scouting, and it.4 gives him a far clearer idea of the problems — involved as a whole than he could possibly ~ get otherwise. This work has been found ~ to stimulate the private’s interest to such — an extent that he is gradually fitted for — assuming any responsibility which an emergency may thrust upon him. a r _Arabic legends; the floating, violet- ® ‘is the clay-ball, floating soap so ‘popular with the naiives of India. With each purchase of rice the Chinese housewife expects a small quantity of ‘rice-bran. About a teaspoonful of Popular Science Monthly 563 | It Would Take a Book to List the World’s Soap Curiosities HERE are varieties of soaps to suit every taste and clime. There is the dainty fit-the-palm toilet soaps of the harem, with the national -star-and-crescent emblems of Turkey inscribed on them; the soaps of the Holy Land and Armenia, with their — ES . az perfumed soaps of the Greek coast; the human-fat toilet soaps of Paris, |#——=a———rs=e _and others too numerous to mention. _ The two soaps illustrated below, however, may be put in the class of the super-curious. One is the primitive ‘Chinese rice-bran soap and the other me, This type of watering trough provides a resting-place this bran is placed in a small muslin for pedestrians and a shelter from sun and wind for bag and boiling hot water poured over the horses. It takes up comparatively little space ‘it, making a thin, gruel-like fluid. : : Using the bag as a friction brush the skin is The Two-in-One Idea as Applied to effectively cleaned without utilizing any of Watering Troughs the animal fats. Bre i ae of Gapen oft “Ting ater ext hows tthe iste fusorial earth. The color ranges from ae = oe ‘ e He the Hic 1 a sae dark brown to black brown. The dusky- ee ae eee eee OPAC’ skinned boys of the Malabar Coast not only Pe ee ee wat i use this soap for toilet purposes but they pol piper le =. adie cs * ages ie: play ball in the water with it. gs p about thirty- six square feet of the corner, which is an exceptionally busy one near the heart of the city. The new arrange- ment shuts off the sight of the water- ing trough en- tirely from the sidewalk and pro- vides at the same time a resting place for pedes- trians and a shel- ter from sun and wind for the horses. The seat and trough are of concrete and the back of the seat is so wide and high that HE commodious and substantial-look- Above:: The clay-ball soap used in India is madeofcopraoil,resin, | there is no danger of splashing. potash and clay. At The trough is arranged at a left: Chinese rice-bran convenient height, so that soap. Both of these aestaiaie ain aes verte ac eaei oe : lio dleanse by fic: horses may drink without the tion ‘father than lather driver being compelled, to get down to loosen the check-rein. 564 © Brown and Dawson Popular Science Monthly To build a steel bridge over a chasm four hundred feet long Japanese railroad engineers constructed their temporary falsework of bamboo. This intricate network of poles is four hundred feet high A Grass Bridge. A Remarkable Feat in Civil Engineering RIRCE bamboo is a grass the bridge il- lustrated is literally a grass bridge, its supports consisting of thousands of bamboo poles tied together to form 4 temporary falsework. The intricate structure is the work of Japanese bridge builders who were obliged to construct the bridge without interfering with railroad Passenger and freight traffic. Because lumber is scarce in Japan the engineers had to rely upon the serviceable bamboo. The bridge is four hundred feet long and one hundred and twenty-five feet high. As will be seen in the photograph the two masonry bases of the bridge are already completed. Two steel members already span the canyon, supported by the bamboo poles. The largest pieces of wood to be used in the construction of the bridge are those forming the superstructure—round poles supporting the weight of the top steel beams. When the steel bridge was com- pleted the bamboo falsework was taken apart and removed to the next bridge- building job. Bamboo is a long wearing material so that the framework may be used over and over again. A New Use for Rhubarb. You Can Clean Pots with It fA peers UM has won the housewife’s endorsement as a most satisfactory ware for kitchen utensils. But the kitchen maid is not so well pleased with it. Its beauty lies in its brightness, and when it is discolored, ‘Madame’ is so particular about how it is cleaned. If it is scoured, care must be taken that it is not scratched in the process. 5 Scraping must always be done with a wooden spoon since aluminum is soft -— scratches easily. Strong alkalis are no | available because they attack and dissolv 4 the metal. Only mild soaps must be used. How then can that horrid discoloration b removed? It is very simply done. . Take a piece of rhubarb, either fresh 4 canned, cut it into small pieces and boi | the pieces in the discolored kettle until it is. clean. The acid of the rhubarb will remove the discoloration without in any way injuring the metal.” Of course th 4 rhubarb used for the purpose must be thrown away afterwards. When a vessel has been cleaned in this way it will need only a little rubbing up to secure a bright” 4s metallic surface. j eed i vd ee Making Clothing from a Fabric Woven from Nettle Fiber _JE agree that war is—all they say it is. ‘ -But the spur of necessity which it has applied has brought forth a host of in- ventions and new ideas. Today, because cotton and wool have been requisitioned for the armies and supplies for general purposes have been curtailed or cut off, the Germans are making a soft, lustrous material from the fiber of nettles. It is thin and strong and makes up beautifully into articles of _ clothing. ~ _ Several years ago experiments were made _with nettle fiber but difficulty was en- countered in separating the fibrous from the vegetable matter. Muriatic acid was used _ for the purpose, and a dessicating process "was also tried, but results were unsatis- ae 4 fi _ all difficulties and leaves the fabric soft _ and pliable enough for any use. _ Special crops of nettles are now being cultivated. There are twelve thousand _ trustees and public officials promoting the collection of them. _ Was This Inspired by the Recent Prohibition Movement? - INE bottles exposed on the sideboard = may be perfectly useful articles. But _ when the prohibition advocate comes to call, _ there is a grand rush to clear them away. _ A New York woman comes _ to the rescue with a hollow _ doll into which said bot- _ tles always disappear “when not in use. __ These considerate _ dolls, as the illus- _ trations show, are made to fit over the bottles, com- pletely concealing them. The main _ portion of the bot- tle is concealed by the body of the dolland theclothes ~ factory. The method now used overcomes Popular Science M onthly 565 The front handles are held in one hand and are continually drawn in and out by pressure Strap It on Your Neck and Cut Your Hair Yourself HOULD every barber in the United States go on a strike the invention pictured above would surely prove popular. You strap to your neck a yoke somewhat similar to that used on oxen. On one side of this, a carrying-bar is pivoted; on the rear end a hair-clipper is held, while on the front end are operating handles. The clipper consists of a number of shears some- what like sheep- shears operated by two levers at- tached to the clip- per. A guard is provided to keep these a safe dis- tance from the head. There is a string-and-pulley arrangement con- necting the front operating handles with the two levers so that the levers may be worked by the handles when the “‘operation”’ is progressing. To use the apparatus in which it is dressed. : The head of the _ doll is hinged and is shaped inside to fit the top of the bottle. You have only to throw back the doll’s head to pour out a drink. The device might also be used to conceal large-sized medicine bottles on the table of the sick-room. The hollow doll, pushed down over the neck of the bottle, completely conceals it from view you simply adjust the clipper the dis- tance from the guard at which you desire to cut your hair (thus regulating the length), keep the handles going and move the clippers about by swinging the carrying-bar upon its pivot until the entire head has been gone over. (The Gasoline Caddy and Errand Boy With a gasoline foot-cart one boy does the work of three York, has bought a gasoline foot- cart for his special delivery service. The result has been an increase in business A GROCEK on Manhattan Island, New stands while driving and his weight is carried between the wheel centers, so that the balance is easily maintained. He leans on the handlebar for support and to steady At left: The foot-cart is — used as'a tender on the automobile to summon help to the car in a hurry Below: The golf caddy finds it a convenience and an economizer of time and temper over the links as well as a saving in money of $21.60a week. Formerly this grocery, which also handles meat, paid three boys to handle special rush orders for late dinners at the rate of twelve dollars each a week in addition to their ex- penses of about six dollars a week. One gasoline foot-cart now does the work of the three boys. Gasoline and oil for the gas-cart costs about forty cents a day, each day’s work averaging one hundred miles. The machine itself costs only one hundred dollars. Hence the grocery saves over $1100 a year. Even if a new cart is bought every year the annual saving is still one thousand dollars. The foot-cart is also being used by golf caddies; by salesmen who make many calls a day; by a theatrical producer who uses it as a tender on his automobile to summon help in case the large machine gets into a mudhole when he is in a hurry to be on his way, and by factory messengers in large plants. This miniature one-passenger machine has a pressed steel platform, suspended about four inches from the ground between pneumatically tired wheels. The motor is attached to the front wheel. The rider hour 566 i The delivery boy speeds away at the rate of twen- ty-five miles an with his basket on his arm + eS a a er baie taltand himself, steering and controlling — the operation of the machine at the same time. Both the brake — and the clutch are operated by | moving the handlebar forward or ~ backward. The speed can be regu- — lated as desired, twenty-five miles _ an hour being about the maximum. The delivery boy carries his basket on” his arm, and if he has other bundles to be delivered on the same trip he secures them to the sloping front of the foot- -platform and sails away with perfect ease and evident: enjoyment. His machine is so narrow that he can make his way through crowded thoroughfares without slackening speed. — j : 3 . - same time. Shoot Your Deer from Horseback with This Saddle Gun N the Southern part of the United States " game is sometimes shot ' from horseback. Only - _ experienced hunters can _ handle a horse and keep a gun steady at the In order - that the ‘‘tenderfoots”’ _ of a party may do some _ of the shooting too, a West Virginian has de- vised a _ saddle-mount for their guns. 'means a gun can be - swept _ position and_ steadied - until fired. By its in almost any This is accomplished, _ asthe illustration shows, _ by a treble-jointed _ mounting. _ joint is a swivel, allow- _ ing the gun to be-sw ept _ horizontally. The first The sec- é ond, a_ball-and-socket . joint, permits motion in : meevertical direction. The last of the joints enables _ the entire gun to be Z 3 sidewise with respect to the _ horse. 4 fine adjustments to be easily made; so that 2 The ball-and-socket, of course, allows very _ between the three joints, a gun can readily _be aimed in the exact direction that would _ be required and held perfectly steady until p fred. Three different joints on the gun saddle enable the gun to be swept in any direction Popular Science Monthly © Int. Film Serv. Her first job was painting seventy- five smokestacks for a _ distilling company. She did it practically alone and in a satisfactory manner 567 How a Young Woman of Kentucky Rose to Great Heights ERVES for the women, but nerve for the men”’ was the un- expressed distinction drawn before the days of the suffragette and of the great war. Although the female of the species may still scream at sight of a mouse, she has proved equal to so many emergencies that it can no longer be said that “nerves” are her dis- tinguishing characteris- tic. A case in point is the young Kentuckian in the accompanying photograph. She is Miss Mayme Pixley, and she becameasteeple- jack by chance, not by choice. Her father, who is the senior mem- ber of the present steeplejack partnership, had a contract for paint- ing seventy-five smoke- stacks for a large dis- tilling company, when he fell and broke his leg. The Pixleys felt that they could not afford to lose that contract, so Mayme (we like the Broadway spelling of her name) stepped into the breach—or rather into the breeches —and proved that she could wield a paint- brush as efficiently at the top of a smoke- stack as she could around the table-legs in the kitchen. She finished all of the seventy-five stacks and received the full con- tract price. That was six years ago. Mayme is still rising in the world upon occasion, with her paint-pots swinging beside her and her father meeting her strokes on the opposite side of the stacks. Although she does not claim to be a “‘new woman”’ or to have very ad- vanced ‘ideas on the question of woman’s place in the world, Mayme believes that a mere matter of skirts should not be allowed to stand in the way of work to be done if one is able to do it. 568 Joun EMEDOUGALD) TREASURER | giry AND COUNTY OF SAN FRANCISCS j a Tiiiiiis What a million dollars in gold looks like. The fifty thousand twenty-dollar gold pieces in this display weigh one and seven-eighths tons Did You Ever See a Million Dollars in -Gold? They Weigh Nearly Two Tons N a recent celebration held in San Francisco, one of the chief attractions was a pile of a million dollars in gold. The privilege of having a good look at all this money was given the guests by the City Treasurer who offered to make the display before the coins were released on their separate adventures in the business world. There are fifty thousand twenty-dollar gold pieces in this display,- which means that nearly two tons of gold had to be brought from the treasury. The coins were all minted at San Francisco within the past year; and if they were placed one on top of the other, a pile four hundred and seventeen feet high would be formed. Such a pile would be nearly one and a half times the height of the large dome on the Federal Capitol at Washington. Look Out for Automobile Gas—It Is Fatal RE you in the practice of “warming up’ your auto- mobile engine in the garage with the doors and windows closed? If so, you stand a good chance of being asphyxiated by the exhaust tent or laced up into a Popular Science Monthly gases. So imminent, indeed, is the dan- ger, that the United States Bureau of Mines has sent out a warning against operating au- tomobile engines in small garages where the ventilating facilities are poor. According to the Bureau the air in the garage is rendered decidedly dangerous after the automobile engine has been run- ning fifteen minutes. The gas is carbon monoxide; it is colorless, odorless, tasteless - and is extremely dangerous. The symp- toms of carbon monoxide poisoning come almost without warning, says the report, and collapse in a garage generally proves fatal, unless outside aid arrives very soon. The Convertible Knapsack—It Can Be Changed Into a Tent at Night A NEW YORK sporting goods house has lately placed on the market a knap- sack which ought to put fifty per cent more fun into a hiking trip. The knapsack does away with the bother of carrying a tent around—for the knapsack itself is merely changed into a tent for the night. The knapsack is unlaced into the dog- tent shown in the illustration. There are flaps at the side which can be used to give proper ventilation. A number of pockets- are also built in the side. In these, all the ordinary articles of camping can be placed. After a bivouac, the tent can be refolded and turned back into a knapsack. The entire outfit can be stored in the inside of the knapsack out of the way. The knap- sack is laced up and strapped on the shoulders where it will require no further attention from the traveler. The problem of camp luggage is solved by this knap- sack which can be opened out to form a comfortable compact luggage-carrier Popular Science Monthly Whiz, Whiz Goes This Electric Buzz- Saw as It Cuts Up a Beef Carcass HY shouldn't beef and other carcasses be cut up electrically, thought a California inventor, Frank F. Wear. So he invented a high-speed electric meat saw which saves two thirds of a busy butcher’s time. - Wear’s saw is driven by a small electric motor mounted directly above the blade itself. The motor is geared to the saw, and rotates it while the butcher guides the apparatus over the carcass by a handle. When a carcass has been placed on a cutting table, an electric button on the handle is pressed, whereupon the motor begins to spin. No sooner has the saw been brought down than it rapidly imbeds itself in the carcass. It is carefully guided as it cuts through meat and bone, and in no time the carcass is severed. Regulating the Automobile Search- light by a Simple Push Button WESTERN manufacturer of auto- mobile searchlights has introduced an ingenious method of controlling the circuit to the lamp by means of a small push- switch similar to those installed in handles of electric vibrators, vacuum cleaners and _ tapls. Heretofore it has been necessary to _ regulate the lighting of a searchlight either - by means of a switch on the dash, which is _ somewhat inconvenient, or else by means ‘ q of a loose plug extending from the lamp. _ The new method makes it possible for _ the hand that moves the lamp in various HANDLE SWITC The lamp is operated by simply pushing the button. This makes it possible to swing the searchlight in any desired direction and to regulate the lighting at the same time ; perlormed by machinery. SPOTLIG GHT PUSH pide 4 569 The high speed of - the saw enables it : to cut through the carcass in a frac- tion of the time. o-dinarily required directions also to control the current simply by pushing buttons. When the light button is pushed the current is “‘on’’ and the lamp is lighted. When the dark button is pushed the current is “‘off.” The switch, sometimes called a ‘‘tool- handle’’ switch, has an insulating tube which is placed inside the small neck of the lamp. A sleeve of insulating fiber protects and separates it from the metal shell. The push buttons are placed in position after the switch is slid into the neck of the lamp. Turning Out Helmets for the French by the Thousand Y their “quantity production of hel- mets,”’ the French are turning out fifty thousand helmets daily. Practically every operation, from cutting to painting, is Each helmet is made from four pieces stamped from sheet steel. After the pieces are rivetted together, the helmets are sent to the painting room. Here machines are used to spray the paint on the hel- mets and in the crevices formed by the rivetted pieces. Then the lining and chin straps are made and adjusted. Sentinel Rocks and They relate chapters of tremendous earth movements in the past Mushroom pillars of sandstone capped with ‘an iron-stone which has protected them from more extensive erosion HE western portion of the United States is full of strange rock forms— lofty natural towers, pinnacles and monuments, many of commanding dimen- sions. Some of the rock towers are composed of relatively soft material, such as sandstone, and their history has been one of rapid erosion and disintegration; others of granite stand seemingly unchangeable, yet their very forms show that they too have been the playthings of the elements. The light-colored sandstone mushroom- like pillars which are numerous in the vicinity of Monument Park, Colorado, are the visible remnants of a great bed of such sandstone, which in a past geologic age covered this portion of the United States. At intervals through this bed of sandstone there were thin strata or layers of a harder iron-stone, fragments of which are now seen as cappings of the sandstone pillars, pro- tecting them to a considerable degree from erosion. The altitude of these sandstone rocks is about five thousand feet above sea- level, yet they were the ocean’s bottom. At another point, near the Garden of the Gods, Colorado Springs, the rock towers are of a somewhat harder sandstone. The Major Domo, as it is called, is one of the most striking of the sentinel rocks of this strange garden. It is of red sandstone, and one of the remnants of a great bed of stratified sedimentary rock which, in the upheaval of the Rocky Mountains, was actually turned on edge. The “grain” of the rock, therefore, now runs vertically whereas originally it lay flat. The leaning pinnacle surmounting one of the ridges of the West Elk Mountains, in Colorado, is a rock of great strength and resistance to erosion. . The ridge consists of rock which was long ago forced up from the bowels of the earth, hot-and liquid, and intruded into the layers of sandstone and other sedimentary rocks _ nearer the surface in a mass several thou- sands of feet thick. It then gradually cooled, consolidated and partially crystal- lized into hard rock. Later, erosion strip- ped off the sedimentary rocks and carved the hard rock into one of the West Elk Mountains, on which may be seen untold numbers of such pinnacles. The big Bad Lands of South Dako constitute a large area of very soft clayey sandstone which was once the bed of a great inland sea. It is. now a well elevated region and the elements have cut and carved the rock into every conceivable shape. There are human and animal faces and forms, and towers and ruined castles and palaces, a perfect riot of possible and impossible shapes. The disintegration is in comparatively rapid progress and the soft rock is continually scaling and falling away from the columns and pinnacles. EYO Sculpture That Was Centuries i At right: In the Bad Lands of South Dakota the soft clayey ‘sandstone has been cut and carved by the elements into many fanciful shapes in the Making The Major Domo, a remnant of a bed of stratified rock which in the upheaval of the Rocky Mountains was actually turned on edge. Note the human figures to which the atrow points for height comparison The leaning pinnacle of the West Elk Mountains in Colorado. The surface is composed of a series of pinnacles like the teeth of a giant saw. It guards an impass- able ravine of ungaged depth 571 Sentinel Rock, at the mouth of Sentinel Creek in Glen Canvon; Utah. From one point of view the rock is said to resemble a woman Nature Supplies Boise with Hot Water How the city uses boiling artesian water for its swimming pools and its laundries CENTRIFUGAL PUMPS 144 FEET BELOW - GROUND ——~ 400 FT TO WELL ————__-.--_> bo ee : Four wells supply Boise with nearly a million gallons of hot water a day hot water supply—a natural artesian flow of 800,000 gallons of water a day with a temperature of 171 degrees Fahren- heit which is only 41 degrees below the boiling point. In addition 450,000 gallons a. day are pumped. School buildings, hotels, boarding houses, laundries and residences to the number of one hundred and thirty-eight are supplied with the hot water, both for heating and domestic use, and during the summer months sixty addi- tional buildings are supplied. The great Boise natatorium, a building 215 by 200 feet and over 100 feet high, with a swim- ming pool 65 by 125 feet and with shower and other baths, uses this natural hot water. The water is believed to have great medicinal and stimulative properties, be- cause it contains a large percentage of soda, potash, lithia, magnesia, iron, etc. The water comes from four wells 400 feet deep, two of them eighteen inches in diameter and two six inches. The larger wells are equipped with centrifugal pumps located 144 feet below ground. One of these ae city of Boise, Idaho, has a curious CONTINUOUS WASTE ee ibis? 4 FOR CIRCULATION >= : a es ae ee a ig - Bot wareR suppuicD AT A oo ane TEMPERATURE OF 166 DEGREES 'F osmne® CONTINUOUS WASTE a, EF csi rina FOR CIRCULATION - go” HOT WATER SUPPLIED") > fee a? -”. ATATEMPERATURE OF : 158 DEGREES F The swimming pool at Boise which receives its natural hot water from inexhaustible springs raises the entire available supply of water, the other is held in reserve. With no pump- ing, the natural flow is 800,000 gallons daily, ‘which is one of the heaviest artesian flows known, either hot or cold. Only a few wells in the United States have developed over 1,000,000 gallons a day, even with pumps. The Boise wells are owned by a hot and cold water company, and, while others have driven a number of wells on adjacent land, no additional hot water supply has been developed. The use of this natural hot water for heating purposes extends back for a period of twenty-five years, but it is only within the last few years that the available supply has been fully developed for general use. The maintenance and operation of the hot water part of the system requires a force of four men during a period of eight months and one man for the remaining four months of the year when the wells are operated without pumping. The piping in the natatorium and other buildings where the water is used corresponds to that of the ordinary system of hot-water heating. wil ew eT a ee ips ee a ete hci te tS me i ae ‘constructed as to inclose an “ordinary electrical heater. The Popular Science Monthly An Electric Comb for Drying the Hair After the Shampoo ERE is a boon for the hair- dresser, barber, lady’s maid or for the woman who is clever enough to shampoo herself with- out assistance. It is a comb so body portion of the comb, hollow and cylindrical, is pro- vided with grooves into which the teeth of the comb fit. The electrical heater is con- tained in this hollow cylinder. Extending through the tang and the handle, is a metal tube which serves as a conductor Tunning to an ordinary lamp- socket. The comb may be taken apart and cleaned and thoroughly ster- ilized in a sterilizing liquid with- out danger of wetting the heater. It is as easily reassembled, and the parts fit together so snugly that there is no rattling or unsteady movement during thé operation. The amount of electricity used is small but is sufficient to dry the hair thoroughly in a very short time. Thus in asingle operation the two most tedious accompaniments of the shampoo are accomplished; for when the hair is perfectly smooth and free from tangles it is also perfectly dry. Y i > ‘into the bottle. WIRE TO CURREN pa SS Se Le SHELL i if ; IRONING RIBS WOOD HANDLE METAL TEETH Weight the bulb with a small stone and lower it into the bottle; keep it in water and it will finally blossom as on the leit How Did the Crocus Grow in the Bottle? —A Trick for the Amateur Horticulturist CROCUS growing and blossoming in- side a bottle? How did it get there? This is how the idea is carried out. Geta good sized bottle, the neck of which is just large enough to admit of the passage of a crocus bulb. Pour into the bottle about an inch of water. Tie a piece of string around the bulb, in the manner shown in the photograph. Loop the string-around a stone in such a way that the stone is held at the bottom of the bulb. The stone should be a rather flat pebble on which the bulb will rest upright. By means of the string, lower the bulb When the lower part of the bulb just touches the water, the string may be fastened around the neck of the bottle. The bottle should now be removed to some dark place for a few weeks, at the end of whichtime it will be seen that the bulb has sent out num- erous roots. It may be needful to add a little fresh water now and again to keep the level up. Keep the bottle near a sunny window. After a time the bulb will begin to flower. Then the string may be loosened from the neck of the bottle and dropped An electric comb for drying the hair quickly 2 eb down inside. while removing the tangles after a shampoo Keeper Charles Snyder, of the reptile house, Bronx Zoo, New York, extracting snake venom F you are quick and fearless you may manage any snake so long as you are armed with a cane or a piece of wood like a cane. Push the snake around in any way that you can in order to prevent him from coiling. When you have him in just the right position, make a very quick move and place your cane across his neck, just behind his head. Then you have him. He cannot get out of control. Now bend down and grasp the snake in the place where your cane rests, just behind his head. With your left hand put his body under your right arm. No matter how enraged the reptile may be he can do no harm as long as you hold him in this position. His body is held by your arm against your side so he cannot coil around you or around any convenient object. In handling snakes in the house it is essential to keep away from furniture or anything which the snake could coil about. They are very strong and once they get themselves wrapped around any object it is exceeding- ly difficult to pry them loose. Pike county, Penn- sylvania, is known for In case of snake-bite you would need a razor to open the wound, anti-venom serum, a syringe for injecting it and a rubber bandage How professional snake hunters manage the most venomous rep- tiles and extract their poison By A. M. Jungmann Handling Live Rattlers’ the number of rattlesnakes which infest certain parts of it. are sold alive to museums and to individuals for exhibition and other purposes. The snake hunters of Pike county employ the method described when catching the rep- tiles. They carry them home in sacks and store them away in a wooden bin. When the hunter desires to show one of his captives he reaches into.the bin, dexterously whips out a rattler and throws him on the floor. Then he holds out an old hat to the angered snake and permits him to strike it repeatedly. By the time the snake has bitten the hat several times it has exhausted its supply of venom. But even then there would be enough venom left in the fangs to do harm. The hunter, however, feels that the chances are in his favor and does not hesitate to handle the snake freely. When a poisonous snake wishes to bite, or strike, an enemy, it rears its head, lowers its under jaw and elevates its upper jaw in such a way that the fangs are directed straight forward. Then it strikes with incredible swiftness. When the fangs strike, the poison sacs are opened and the venom is injected into the victim as with a hyper- dermic syringe. The action of snake venom is very rapid. Small animals and birds fall to the ground immediately upon being struck. They become paralyzed and die in a few minutes. Removal of the fangs does not make a snake safe to handle, because as soon as one set of fangs is removed others grow. They are supplied with two fangs in the upper jaw. Once in a great while, as in the case of the moccasin pictured on the following page, a snake may have three fangs, a mew one having grown in before the old one fell out. Some snakes will inject as much as a teaspoonful of ven- om into an enemy. Poisonous snakes AVA Men make a business. of catching these dangerous snakes. They ee Oe Shas ett rm _ = ———S SSS Popular Science Monthly 5 With a quick move- ment place the cane acrosstheneckofthe snake just behind the head, then grasp him in the spot where the cane rests are captured in order to secure their venom for the prepara- tion of anti- venom snake serum. Thisse- rum, if injected into a person who has been bitten by a snake, will save his life. The neces- sity of the prepara- tion seems remote to us who live where ven- omous snakes are comparatively rare. But in some parts of the world snakes do much to keep the death rate high. In the Indian Peninsula, for example, the Cobra, the Krait and a few other venomous snakes cause the death of 25,000 persons every year. Fatalities from snake bites are numerous in Burma, Indo-China, Australia, the Dutch Indies, Africa, the West Indies and Tropical America. _ Treatment for snake-bite consists in immediately making a tourniquet some distance above the wound to prevent the blood from carrying the venom through the system, then making deep incisions in the wound with a razor or a sharp knife to permit it to bleed freely. Permanganate of potash should be sprinkled into the wound and then anti-venom snake serum Should be administered. If these pre- cautions are taken quickly the danger of The usual number of fangs is two, but some- times a third one grows in before it is due When held in this way the snake is perfectly harmless. Care should always be taken not to give it a chance’ to coil around anything the bite prov- ing fatal is greatly les- sened. Ordinarily, however, even the most ven- omous of snakes will not harm a person unless it happens to be struck, stepped on or other- wise annoyed or alarmed. In this coun- try snake-bite fatalities are rare. Potash from Seaweed—An Industry in the Making N. ambitious project to obtain potash from seaweed in the Sargasso Sea, in the North Atlantic Ocean, is planned by W. S. Warner, of Tampa, Florida. He intends to build a special vessel of rein- forced concrete and equip it with machinery for hoisting the seaweed from the ocean and reducing it to ashes. After running the seaweed through three successive sets of heavy rolls to remove the water, it will be passed through rotary drying kilns, burned, and the ashes, in which the potash content is concentrated, stored in the hold of the vessel. Mr. Warner plans to install an equipment capable of producing two hun- dred tons of ashes per day. The Sargasso Sea is literally covered with seaweed. 576 Grind Your Valves at Home. A Machine Made for Car Owners GRINDSTONE CENTERING HANDLE ROCKABLE BRACKET The valve head is held at an angle against the rotating grinding wheel which drags it around and bevels its edge into a perfect circle N -automobile cannot work efficiently unless the engine-valves are in good condition’. The valves control the supply and the exhaust of the vaporized gasoline in the engine cylinders, and if they should wear unevenly and begin to leak, the maxi- mum amount of power cannot be obtained from the fuel. Hence the valves should be ground often. A machine for grinding the engine valves accurately and rapidly has recently been invented. The valve-heads, which must be ground perfectly round so that they sit tight against the circular ports or openings in the cylinder, need only be adjusted in this machine, and the grinding will proceed automatically. Evidently such a machine would enable an autoist with average mechanical skill, to grind down the valves of his own car. The illustration shows a valve-head adjusted in position in the machine. An emery grinding-wheel is rotated at the front end and the head itself is held in place by a holder at the other end. The holder can be moved length- wise in its bearings, while the turn-table on which it is mounted allows it to be swung at an angle to the plane of the grinding wheel. The valve-head is pivoted be- tween two steel points on the holder so that Ke itcan freely rotate “% on them. A small electric motor, which is geared to the The front wheel of a bicycle is removed, placed in the rear, belted up with the other and an exerciser for leg muscles is made Popular ‘Science Month ly grinding-wheel, is then turned on. The revolving wheel, with the edge of the valve- head in contact with it, drags the head continuously around. At the same time, the wheel continuously ‘‘strikes off’’ side- wise from the edge of the valve-head and consequently bevels it down. The valve- head rotates always a fixed distance from the plane of the grinding-wheel, so that a perfect circle will be obtained on the head. A person of only ordinary skill can grind ‘a_ valve with the machine described, on account of the fact that the valve is always in the proper position with relation to the. Any standard valve can. be ground quickly and easily, as the only. change in the machine’s adjustment is to grinding wheel. adapt it to a long stemmed valve or a short stemmed valve. This is done by changing the position of the arm on the shaft. When valves having stems of about the same length are being ground it is not necessary to change the position of the arm, : in view of the fact that the socket member is adjustably mounted in the arm. The Bicycle to the Reskiae 3 in Leg Treatments Or of the simplest devices yet heard of for restoring strength and agility to soldiers’ legs after they have recovered somewhat from the effects of wounds, is utilized at an electrical gymnasium which has been started at Chateau D’Oek, in Switzerland, by a French Adjutant and CS. McCarty (Leicester Regiment), in the interest of British soldiers who have been wounded and are convalescent. The bicycle employed for the purpose need not be of the latest model. Only the frame and the two wheels are necessary. Not even tires are required. The front wheel is taken off and the frame is fastened to a stationary sup- port. The wheels are arranged at the rear as shown in the accompanying or rope support- ing a weight is carried over the wheels. illustration. ~ The tires are re- © moved and a belt ~ es a Te ke ee ae Se oe ee Ls ss Feelin wit at ‘of building of this particular type of Popular Science Monthly Why Navies Have Small = Armored Cruisers RMORED cruisers are fast vessels of from eight to fourteen thousand tons in displacement, which have their vitals, such as guns and machinery, protected by armor plate. They do not carry as heavy guns as battleships, and are supposed to have greater speed. There seems to be a cessation vessel in recent years, the main de- pendence in fighting being placed in dreadnoughts, battle cruisers, destroy- ers and submarines. Some few scout cruisers are being built by the naval powers. These, as their name indicates, are fast, lightly- constructed cruisers of from five to seven thousand tons displacement, possessing the highest speed attain- able for vessels of their size, great cruising radius, and armed with guns of comparatively small caliber. They are used to locate the enemy and are known as the eyes of the fleet. Spinning a Top by Means of a Spring DEVICE for spinning a top in a brand-new way has been invented by George John, of Detroit, © Michigan. It operates*by ~- aspring, which gives the top:=- its whirling motion as it rapidly unwinds. _ As the illustration: shows; the spring is fitted around a short wooden stem attached in the center of a wooden knob. This stem protrudes beyond the end: of:the knob so that it may fit into ’a corresponding hole bored in the center of the top itself. When the stem is placed in the hole and the knob is turned, the bot- tom end of the resilient spring is caught by a projection upon the top and the spring winds up. The smaller stem in the knob is then pushed down into one of the several holes bored into the top, to hold it in position. The top is aimed and this stem pushed up. The compressed spring then pushes the top away from the knob while it un- COILED COMPRESSION SPRING W STEM ATTACHED TO HANDLE all the The trigger of the burglar trap is so delicately adjusted that the slightest movement of the door will operate it Defending the Home with a Mousetrap Gun OR protecting the home against bur- glars, Daniel Cruice, of New York, offers us the home defence ‘‘gun,’’ shown in the accompanying illustration. The “‘gun’’ uses real gunpowder—not to shoot the offending burglar, but to awaken the sleeping household. The contrivance is set by drawing back the skeleton hammer against the tension of its spring and by catching the hammer in the trigger. It is then placed on the floor with its trigger in contact with the door. When the door is opéned, the trigger is hit, the hammer tripped, and the detonating powder fired. No burglar would dare enter after such a noise. Tooth- ed edges prevent the “gun’’ from slipping back when the door strikes -it- Of course the device should not be set until members of the winds. It spins rapidly and with a loud hum. A wound-up spring in the hanaic of the top starts the spinning household are safely in for the night. Bathing in Melted Wax If your joints are stiff, boiling wax poured over them may bring relief By the Paris correspondent of the Popular Science Monthly ile Maal eg MS HE wax bath is a new idea in medicine and is recommended as a curative measure in a number of ailments, such as rheumatism, various disturbances resulting in skin troubles, inflamed and painful joints, and so forth. Incredible as it may seem, it is possible to pour boiling wax on any part of the human body without causing burns. The treatment originated with Doctor Barthe de Sandfort of France, who found the wax bath very successful in a number of stubborn cases. The wax he uses is a paraffin composition prepared after his own formula and possesses curative properties which would not be possessed by the ordinary wax candle. The patient who is to receive a paraffin wax bath is placed in a wicker basket so built that his head is slightly raised. The basket is lined with a material impervious to wax., When all is ready the hot wax is poured over the patient so that his entire FOE ee ae RE Photos by Boyer Note how the wax forms a‘kind-of* plas- ~ - ter cast over the legs as soon as applied At left: The cradle for the partial bath. In this instance the patient’s arm alone was coated with wax from elbow to fingertips. body is coated with it, or the part which is. to be specially treated. When the wax cools, the patient looks as if he were covered witha plaster cast. After the wax has been poured on, the patient is covered carefully with a quilt, and remains in his wax bath just as long as the physician deems it necessary to bring about relief. When a patient is taking an entire wax bath, which means when he is covered with hot wax from his chin to his toes, the wax is" not quite as hot as when a patient is taking what might be termed a partial bath. That is to say, if a patient is suffering from, say rheumatism in his elbow, he can stand the wax at a slightly higher temperature than he could were it poured all over him, for the simple reason that the skin over the elbow joint is not so sensitive as that of other portions of the body. Doctor Barthe de Sandfort has devised a method for heating his paraffin so that the composition is not altered. The temperature may be varied in greater or less degree, and large or small quantities of paraffin may be heated as it is required for use. steam which is regulated by valves. 578 Pouring hot paraffin wax ovér a patient. | © r . e ’ ’ ' Oe ee eee ee a ee ee The paraffin is heated by bl eas LE yr a a ol Wet yk * TO nat ae ae? Ten _ corners and railway stations. Popular Science Monthly After the patient has been in the bath for about eight minutes his forehead will be covered with a slight moisture and his respiration will become accelerated. After a time, varying from fifteen to thirty minutes, the wax is removed from the entire body and the invalid then lies down and rests. The fact that he is not burned always causes the patient a great deal of astonish- ment. The real reason is that wax has a very slight capacity for holding heat. Although it becomes very hot during the 579 melting process it loses its heat almost immediately upon being removed from the flame or from over the steam. Con- sequently, although it is boiling hot when it leaves the spout, and is still hot enough to be poured when it reaches the body, it is not sufficiently hot at the moment of contact with the flesh to burn it. This new wax cure has been recom- mended as a means of aiding soldiers to recover the use of joints which have been stiffened through injuries received in the war. A patient completely immersed in a wax bath from chin to heels. with a material impervious to wax. In this he lies, perspiring freely, for a specified time A Perfume Spray from a Penny Slot Machine NEW slot machine has made a bid for popularity on some of our_ street For only one penny deposited in the slot you can spray your clothing or your pocket handkerchief with perfume of any preferred odor. The mechanism is simple. After dropping the coin in the slot, you press a lever in the ‘usual way. This operates a bellows, forc- ing air through the perfume container and producing the spray. The weight of the coin passing down through the chute, over- balances a latching device and moves it away from the lever, while a movable arm drops to allow the bellows to operate. It may be true that those who delight in the perfume of the heliotrope, the violet and the rose, and who occasionally neglect to provide for their olfactory satisfaction before leaving home, may bless the ma- chine; but there are those to whom the thought of a dozen different perfumes mingled with the stagnant air of a crowded car is anything but pleasant. However, the amount obtainable for the penny in- serted in the slot is not likely to be sufficient to be objectionable. The basket couch is lined Why Does Oil Poured on the Waters Calm the Sea? AVES in mid-ocean are caused entire- ly by the action of the wind. The adhesion between the rapidly moving par- ticles of air which compose the wind and the surface particles of the water causes the water's surface to be dragged along with the air. Small ripples are immediately formed. These ripples soon overtake others near them. They unite, and due to the friction between the water particles, each succeed- ing ripple piles up on-the top of previous ones. Just as soon as oil is spread upon the water, however, the size of the waves is reduced like magic. The reason for this is interesting. Oil, unlike water, has very little internal friction between its particles. The ripples of oil formed by the wind, there- fore, cannot pile upon each other to any con- siderable height. Hence, water waves can- not grow in an area of oil placed about a steamer. They begin to fall down instead. By the time these waves reach the boat they will have lost their formative ripples and the result is a perfectly calm surface over the portion of the sea through which the boat is making its way. i ol ey a ire It took five men to throw Moses to the ground, “hog tie’? him and then shoe him properly Moses: Didn’t Want to be Shod. So They ‘‘Hog-Tied’’ Him HEN forest rangers and government engineers are in the field many miles away from the nearest town, they frequent- ly have to do their own horseshoeing. This is a comparatively easy task if the animal. is tractable and accustomed to-the opera- tion. But often the men have to ‘‘hog-tie”’ their horses—that is, throw them to the ground and tie their feet together. To throw a horse to the ground without injur- ing him is no tenderfoot’s job. It requires much patience and muscular power. The horse shown in the illustration is Moses, one of the animals attached to a topographical engineering party in Oregon. Moses wouldn’t stand and allow his captors to shoe him. Consequently he was forced to submit to all the indignities of the hog- tie. Three men are holding his feet by ropes, one is holding his head and the other, leaning over him, is doing the shoeing under difficulties. The sixth man in the party has a cub bear skin which he is tacking to a dead tree. When the men have finished shoeing Moses they will roll him over so that he will be on the down-hill side. This is the only position in which he can regain his newly-shod feet without considerable danger of hurting himself. Popular Science Monthly An Alarm That Warns You of a Leaking Tire i frequently happens that air leaks slowly from a tire without the driver’s knowing it. The tire becomes flat and the rims of the wheel cut into it. To warn drivers in time, George F. Young, of Indianapolis, Indiana, has invented an electric alarm which can be attached to any wheel. It consists of an electric switch which is mounted on the axle of a wheel. The blade of this switch projects toward the spokes of the wheel.» The end of the blade stops very close’ to the spokes, though enough space is left to enable the blade to barely clear them. = ‘Working in conjunction with the blade of the switch is a metal finger mounted on one of the spokes of the wheel. This finger can slide radially to the wheel, but a spring normally holds it away from the axle, with one end up against the underside of the inflated tire. finger will clear the projecting blade when the tire is properly inflated. Just as soon as the tire begins to flatten, the finger is pressed radially inward and it strikes against the projecting blade. The switch is thereby closed, and an alarm, such as a well located light or a buzzer which is very easily heard, is operated. = The various switches are mounted so that ‘they do not rotate with the wheels with which they are associated; but they are placed ‘in’.a position so that they will be thrown to one or the other of their closed positions when the tire is punctured or if the air suddenly leaves it. This method of mounting may be carried out in several different forms. The one most convenient is shown in the accompanying illustration. sé GROUNDED SWITCH. CLOSED Wipe a “:, TO.BATTERY ahi \s WHEEL SPOKES U-SHAPED SPRING NOTCH CYLINDER CONTAINING SPRING WHEEL SPOKES U-SHAPED SPRING » CAUGHT IN NOTCH sf \CYLINDER CONTAINING welt SPRING Cains PLUNGER RAISED BY FLAT TIRE A flattened tire presses a switch-finger in- ward. The electric switchis thus closed, and an alarm in the circuit at once gives warning PLUNGER LOWERED INFLATED TIRE The other end of the. a —_— ee ee ee ee aD as - ee ne Loading Ashes Automatically The endless belt conveyor saves the janitor’s back and the landlord’s money HE endless belt has been found to be a solution of a wide variety of problems. It is even being used now as a conveyor of ashes from large buildings. Thus applied, it far outstrips the older methods of carting up the ashes from the boiler-room by the barrel. Instead, it brings them up and discharges them in- one continuous stream directly into Waiting wagons. The conveyor for this purpose must be portable; it must be one which can be raised into position when in use, and lowered below the level of the sidewalk immediately after- ward. This is be- cause no obstruction can be allowed for any length of time above the sidewalk on any city street. To accomplish the raising and lowering, the conveyor is én- closed in a casing of sheet iron. Two flat rack gears are at- tached to the casing, one on each side. In these, two pinion gears mesh, and when these pinions are turned by the hand-crank with which they connect, the casing, belt con- veyor and all are moved in the direction desired. Hence, when the ashes collected in the engihe-room are to be removed, the they are dumped The buckets on the revolving end- less belt dig into the piled ashes and carry them up to the street where into wagons conveyor is first lifted from its casing in the ground, up through its trap- door, and stationed on the sidewalk. The ashes are then shov- eled into a suitable pit built in the en- gine-room floor, and the belt is started going by the small electric motor geared to it. The buckets on the belt dig into the pile of ashes as they pass through the pit. They are filled automatically and travel upwards to the surface. On reaching the belt- sprocket at the top of the conveyor, the buckets swing around with suff- cient speed to throw the ashes off into the sloping chute at the side. From here they slide into a waiting wagon, and are ready to be carted away. Stolen Cars Send Automo- bile Insurance Rates Up HE increasing number of stolen cars and the small proportion recovered by the police are the reasons given for the raised rates on automobile insurance in Chicago. More than four thousand cars were stolen in that city during the first nine months of last year. The advanced rates on cars val- ued at less than $700 are from twenty-five cents on new cars to $2.25. On 1915 models the advances are from fifty cents to’two dollars, and on the 1914 models from fifty cents to one dollar. 581 382 A Crib, Baby-Carriage and Bassinet All-in One STRANGE new vehicle has been in- vented for the comfort and con- ~ venience of babies and their mothers. It is a combination Popular Science Monthly in my right side—a bullet had gone through my cubes. Had not the cubes been there, I would have lost my life, as the bullet would have gone in my right side and out at the ig! left. Please be sure Se to send my lid to my house when you i have done with it, as crib, baby carriage and*” bassinet so arranged ** that it can be’ corded ; y away and stored in small space when not in use. - The crib is enclosed in a silver-wire screen and is provided with a shel- tering canopy to keep away flies. A mat- tress- plat- form is pro- vided in order to make the crib a downy bed for the young- ster. When the in- fant’s nap is finished, the mattress and board can be lowered. This leaves a roomy little play-space where the baby may romp and exercise without the slightest possibility of injury to himself. His mother knows he is safe and can go about her usual duties. Saved by a Tin Filled with Soup Cubes PRIVATE in the Gordon Highlanders owes his life to a can containing soup cubes. The illustration strikingly shows what happened to the bullet intended for him. Here is the private’s own story: I would not. part with it for any- thing.” We have heard of cases of a much- treasured. Bi- ble, carried above a sol- dier’s heart in obedience to a mother’s re- quest, saving his life, but never before has a pro- saic soup cube . had such a ro= mantic mission. x Above: The crib extended, with its sheltering canopy in place. At left it is be- ing folded for storing away Marks of Age by Which Dressed Poultry May Be Tested HERE are tricks in every trade, they — say, and the average poultry dealer — is not likely to be altogether exempt from ~~ the implication; for there are almost no tests by which the buying public may judge the age of his birds which he may not, if he is so disposed, cover up or offset. For instance, it is commonly known that in a young chicken, goose or turkey the end of the ore is easily bent, like the a cartilage in the human ear, > while in the old bird it is brittle. But this test is © ‘often rendered worthless — by the dealer breaking the — end of the breastbone so — that it seems pliable. The feet sometimes fur- nish a clue. In a young “T had just received my weekly parcel from home on the 24th of September, as we . made the charge at Loos on A private in the Gordon High- landers was saved from death by a can of soup cubes. A bullet passed right through the can bird they are soft and smooth, while in an old one they are hard and the 25th, so I thought I would put my cubes in my pocket as when I got them the week before I lost them out of the parcel. “We went over the parapet on the Saturday morning, and drove the enemy right out of Loos and over Hill 70. All at once I got a bullet in the leg, and about five minutes after I felt a sharp prick «. rough, and if a male the spurs are long and large. Young turkeys have black feet, it is said, which grow pinkish at about thtee years and then turn gray and dull. In ducks and geese the flexibility of the windpipe denotes the age. Popular Science Monthly The Acetylene Life-Preserver. It Blows Itself Up with Gas ERY efficient is the life-preserver pic- tured in the illustration below. All that it asks of the person to be saved is that it be strapped securely around his body. It will do the rest. As soon as it strikes the water it will inflate itself with gas and will become so buoyant that it will keep its wearer afloat until he is rescued. Kurt Nebel, of Chicago, IIl., is the inventor. An inflatable tube lies flat against the body when fastened around it. To this tube is attached a gas bag, with a container for carbide at its lower end. The gas bag is also provided with inlet-valves through which the water enters, finding its way eventually to the carbide and generating gas instantly from the contact. This gas rises and fills the tube around the wearer’s body. Before the gas bag is inflated it is held flat by a gelatin cord which is looped around its center 4 jens system is so and which dissolves arranged as'to form when immersed in water, 2. clearly defined so that the bag can #'°™'78 ge round out. This disten- sion, together with the pressure of the water on the outside, tends to open the inlet valves so that the water may find entrance to the carbide. The device is also used as a buoy for those learning to swim. If thrown out into the water to a “man overboard,” the water will dissolve the gelatin cord and the gas bag will become inflated just as pre- viously described, so that all the person to whom it is thrown will have to do will be to slip his head and shoulders through it and adjust the strap to fit snugly around his body. The device will continue to gen- erate its own . WHEN GELATIN gas for an in- }908 pissouves definite length of time. The wearer’s movements are unimpeded by it. UFE PRESERVER WATER IN WHEN MERCURY 1S THROWN TO RIGHT ELECTRIC CIRCUIT IS FORMED 583 An upward snap of the muzzle of the revol- ver closes the circuit which lights the lamp A New Flash-Light for the Gun ANY and astonish- ing are the varia- tions of the schemes to attach a flash-lamp to a firearm and so make shooting in the dark as nearly infallible as possible. The latest improvement in that line is a self-lighting lamp attached to a pistol, the light staying out until the pistol is leveled at the mark, then lighting automatically. The lamp circuit is completed by a tube of mercury and air, with the mercury so arranged in conjunc- tion with the air that it will move readily. A quick upward snap of the muzzle of the gun moves the mercury in the tube, closing the circuit and light- ing the lamp. A downward snap of Above: The acety- the muzzle of the lene life-preserver gun drives the mer- in operation. It cury forward and will-keep the wearer b z io. eh 4 ‘ afloat for an indefi- reaks the circuit nite length of time again. A lens sys- tem in the lamp is so arranged as to form a clear and easily defined aiming mark, which 4s read- ily adjustable. At left: Device in detail. When water makes its way into the gas bag it gen- erates sufficient gas to inflate the tube 584 © Brown & Dawson Madeira’s winter sport in summer time— sliding down a mountain on a wicker-chair sled Sliding Down a Mountain on a Summer Sled oro of wheeling you down the mountains of Madeira, as you might suppose, the hardy natives slide you down. You seat yourself in a comfortable wicker chair mounted on a wooden sled fitted with steel runners and come down the rocky path of the mountain side as if you were sliding on snow. The human locomotive in the rear steers you down the mountain and pulls the empty basket-cars up again. The Only Railroad on the Seward Peninsula, Alaska, is a ‘‘Pupmobile’’ Popular Science Monthly roads in Alaska soon after that, and as there was not enough traffic over the road to justify the expense of operating locomotives, the regular train service was discontinued. Then the ‘‘pupmobile”’ was instituted. The accommodation for passengers consists of a platform on which are two seats. To this from seven to fifteen dogs are harnessed, and the rate at which they travel compares favorably. with much of our “rapid transit.’ Fur- thermore, it is about the cheapest rail- road to operate that we know of. Six pounds of dog meat a day is considered to be a fair expenditure of “fuel.” HE ‘“pupmobile’”’ is a Passenger train drawn over a regular railroad track by dog-power. The one shown in the photograph is the only one in existence. It carries passengers from Nome, Alaska, across the level land near that town into the mountains. The track is a narrow-gage railroad built in 1900. A high tax was placed on rail- From seven to fifteen dogs draw the two-seated Passenger car over a narrow-gage track at “rapid transit” speed Ce i dS iti eee ae ty VP Pe ne gr ; i 77 a Rag-Time Music as an Adjunct to the S Operating Table J ‘VEN surgeons have a= sense of humor. A patient was rushed to the Ee otursbus Hospital of Chicago, not long 280, ina critical condition. The excitement of getting him there so jarred on_ his erves that when it came to administering e anesthetic, he refused absolutely to pt it. After every augument failed, the surgeons thought of trying to soothe | by playing a phonograph that was in e building. When finally a popular air Sas put on, the patient began to see the ‘humor of the situation, and without further 4 have Yourself with a Buzz Saw— q That’s the Newest in Razors ERE is the most decided departure cs from the ordinary safety razor which we have seen. It is a compact little con- ivance of the press-the-button variety, with the blade fully protected by a ety guard so that there is no Manger of cutting the fingers or of “scratching the face. The blade operates with continuous ro- | motion like that of a circular saw. First you wind up shave without a scratch or the slightest abrasion of the skin, in almost less time than it takes to tell it and without a particle of annoyance from dull blades. Popular Science Monthly The club makes an extension barrel for the revolver giving it greater range How a Policeman Can Use His Club to Change His Pistol into a Rifle HE ordinary hardwood club which the policeman swings so jauntily as he makes his rounds, looks formidable enough to the wrong-doer. But it may prove to be even more deadly than it looks. Sheriff Frank Barnet, of Oakland, California, has devised a plan for combining the club and revolver in one weapon, thus increasing the range and accur- acy of the revolver. The com- bination is made in a moment’s time and may be unlocked as readily as it is put together, so that it is either one article or two, as desired. The sheriff's club is fourteen the mechanism, just inches long and through its as you would a center a hole is bored for watch or a clock; a barrel. This is made then you to join the barrel of the apply it revolver by means of to your a special locking de- well-lath- vice. With its addi- _ face & tional fourteen and press 7) —— NN inches of barrel the the but- CTT revolver is thus con- ton at the verted into a rifle with three side. Ac- times the range which it had cording to before. the inven- It is also claimed that the om C. B. aim is so much improved Collins, of by this arrangement that Des Moines, the burglar or other human Iowa, you nuisance has absolutely no should have ities as tedkhns at the side of the rarce. chance to- get away after he a_ perfectly and Presto! You have a perfect shave has been sighted. beautiful The club is not materially altered in weight by the boring away of a portion of its central interior, so that it can still perform effectual service in its own way. 586 At Last! An Automatic Motor- Driven Tire Pump CREWED in- to the com- pression-cock of an automobile- motor, the novel airpump for pneu- matic tires shown inthe accompany- ing drawing is dis- tinguished by the use of a differen- tial piston and a spring - operated diaphragm in ‘which the tension of the spring con- trols the pressure of the air pumped into the tires by means of an exter- nal notched dial. The pumping of the air is effected - through the use of two cylinders, one large and one small. The larger is open to the gases of the engine, while the smaller is open to the atmosphere at one end. The differential piston, working in the two cylinders, is carried on a hollow piston- rod. As the piston is moved in one direc- tion by the suction of the engine, air is sucked into the small cylinder through a check-valve. On the compression or explo- sion stroke of the engine, the large piston is forced in the AIR IN EXCESS OF DIAL SETTING ESCAPES HERE, VALVE SEAT pressure of the air by opposite direction, and the air is forced into the small cylinder be- cause the check-valve is closed, then through the hollow piston-rod to the chamber controlled by the diaphragm under spring tension and thence to the tire in a tube. Both large and_ small cylinders are water cooled from the engine system. The use of the differential piston on the hollow rod permits the air to reach the tire without becoming im- pregnated with any oil from the engine-cylinder. The pump is operated through a valve in the compression- extends down Popular Science M onthly Jicas TRAP ANDEGRESS fy MOTOR GAS LI Diagram of the automatic motor-driven tire pump. The tension of the spring controls the The pocket is attached to the rear face of the garter and a ar ct ean cock nipple, which valve can be turned on or off from the driver’s seat by means of rod — connections. Air pumped by the device after the pressure at which - the diaphragm | has been set js_ reached, is passed © off into the at- mosphere, as indi- cated in the accompanying ile lustration. In this way. all. the strenuous la- AIR _INGRESS SMALLAIR CYLINDER Wate ADMITTED ae HERE up of the autom om bile. tire is done away with. . GAS ENGINE CYLINDER means of an external dial A New Safety Pocket-Book Is Combined with the Garter PICKPOCKET would have no chance of getting possession of the contents of the pocket-book illustrated, without a strenuous tussle with the wearer. The best of it is that no thief would be likely to sus- pect the existence of such a pocket. Made as part of the garter, it is fastened under the front pad and made to extend down into the sock, as shown. There is a flap which fastens with a glove button arrangement to the outer part of the garter. The pressure of the elastic band serves to make the. closing still more secure. 4 The pocket-book is thus con- cealed inside the sock and is made to lie flat against the leg so that there is no discomfort. If through careless ‘fastening or othe negligence, the clasp shoul - come open while the garter is in use, the purse woulc slip down into the sock ant would be immediately felt so that there would be ne possible chance for it to br lost without the owner’ - being aware of it. It is the invention of Ed-— ward V. Crouse, of Chi- cago, Ill. : “7 ot into the sock - Giving the Teeth a Clean Sweep oe with a Rotary Tooth-Brush [brush is a miniature scrub- ging brush. It works well = Gz no ih in cleaning the urfaces of the teeth. gut in cleaning the between them —the very parts that ed cleaning most—t Eifcicnt. Food will ollect between the eth before it will collect anywhere else. - f not removed it starts 70 decay. Ja CS Popular Shierice Monthly 587 Do You Know That We Americans Have Over a Hundred Volcanoes . ORE than a quarter of the active volcanoes of the world are on United States soil. We have the distinc- tion of possessing about sixty volcanoes in Alaska and in the Aleutian Islands just off the coast. In the western United States, in the Philip- pines and in the Hawaiian Islands we have nearly as many more, making over a hundred volcanoes that we possess (not that we place any value upon their possession). There are but four hundred and seventeen _ Arotary tooth-brush as been invented, When the handle of the brush is rotated certain bristles scrub the surface while others penetrate and clean the crevices throughout the entire globe. which cleans. out the revices between the teeth as well as the : Both surfaces. The brush is guided with ne hand and turned with the other. The metal guard prevents the bristles from uching the inside of the mouth. The ‘ ing bristles rotate parallel to the vices, some scrubbing the surfaces of the eeth and others penetrating into the y BALL OF CORD CORD WHEN KNOB IS DEPRESSED OORD 15 CUT, THEN ADVANCED A Machine Which Automatically. Feeds Twine and Cuts It HE wrapping clerk who has learned the trick of breaking twine only after his fingers have suffered from cuts and burns, . will welcome the appearance of a machine which will not only cut twine at the point desired, but which will feed it along under: a CUTTING BLADE cutter so that the end is Fea always within convenient z < +'| Om 4 KS reach. The machine does Wii ke A. its work with the faithful- or Y ness of a human; there is no blade cuts the twine and more is pulled out = need for the operator to: ‘ watch it as he wraps his bundles. The twine is cut by pressing down a knob which operates the cutting blade. At the same time - the twine is advanced by an arm which moves forward when the knob descends. In this way the twine is fed forward as fast as the knob is operated, leaving, with each stroke of the knife, a slight length on the side of the machine nearest the wrapper to be used for the next package. The twine is held in a cup large enough to accommedate several sizes. It makes no difference how thick or strong the twine may be, the machine will cut and feed it along as fast as the operator works. 588 : The slotted rod attached to the tie bar moves with the steering wheel, causing the forked bar with the lamp to turn likewise Automobile Lights which . Turn with the Roads STATIONARY lamp is of no value in lighting up the road when turning a corner or curve; but a search- light mounted on top of the motor hood may be turned directly on the path to the right or left as the steering wheel is turned, the movement of the lamp being accom- plished by a train of gears between the steering wheel column and the lamp sup- port. The latter consists of a forked rod which extends down through the motor hood in a vertical sleeve supported by a small bracket riveted to the underside. y the of ent base colors are = paint by chemical proc- of used by the large esses. These white wood paint makers. powders, which are —— _ ing : ; called pigments =—j grain Paints are Mixed (white lead and Cross-section of a block of wood showing Like Dough white zinc), are impregnation of the wood by the paint In making paints, ground in linseed the white pigments } oil to produce paints. White lead is pro- are mixed in proper quantities with linseed duced by corroding metallic lead with oil in large mixers containing revolving | vinegar and gases or by subliming lead ores _ knife blades and stirrers, such as are used in ) imspecialfurnaces. White zincis produced a bakery for mixing bread dough. The | by heating zinc ores with coal. Ata high paste formed is then run through mills con- temperature the zinc forms a white smoky taining closely set revolving plates of | ee 593 dressed stone. The paint comes from the mill very smooth, and finely ground. It is allowed to flow into large tanks holding sometimes a thousand gallons or more, where it is thinned with oil, turpentine and drier. Tinting colors are added if a colored paint is desired. Linseed oil forms the liquid part of most paints. When brushed out, it takes up oxygen from the air and becomes solid, forming a rubber-like substance which is very waterproof. When pigments are added to the oil, the same thing happens, but the dried oil is made stronger and the surface to which it is applied is colored, according to the colors of the pigments used. Oil Menhaden fish are not used for food. They are steamed and pressed to extract their oil, which is used in making paint Below: On the right is a barrel filled with dry pigment. The barrel on the left contains the same pigment after it has been milled with the requisite © amount of linseed oil. Conden- sation reduces the volume the soya bean, cottonseed and corn germs are used to some minor extent in the paint industry. Turpentine is produced by distilling the resin that comes from pine trees and is used in paint to make it spread easily, to aid it in drying and to help it penetrate deeply into the grain of wood, thus securing a good bond. Mineral spirits obtained by distil- ling petroleum is used for the same purpose. Varnish Is Made from Prehistoric Tree-Oozings Paints which dry with a high luster or gloss are called. enamels. These are made from squeezed from menha- den fish is used in some special kinds of paint. Oil from the nuts of the Chinese wood-oil tree is very useful for making highly water- proof paints. It has been used by the Chinese for many centur- ies to smear their junks and river zine oxide ground in varnish. from foSsil resins such as copal, kauri, etc. resins, which originally flowed from trees, have been deposit- ies in the earth. They Africa and New Zealand, boats. Oils ex- pressed from Filling cans with the prepared varnish and paints from a battery of storage vats in one of the great paint factories and are found in big lumps. Varnish is produced These ed for centur- are mined in ~ ; b i Telling the Age of Water-Marks On a Lake Shore Zz RECENT investigation of the water “ei level of lakes by two consulting en- ' gineers, one an American and the other a Canadian, resulted in the collection of ‘interesting data on the age of water-marks and stains on the rocks along a lake shore. Moss and lichens, common vegetation in northern latitudes, ' Popular Science Montily 595 Replacing Rags with Waste Tanbark in Making Coarse Paper O-DAY the price of plain everyday rags is soaring high above the clouds in company with thatof most commodities. Its use in the manufacture of paper has there- fore greatly diminished. Not that we are making less paper than before, but because a cheaper substitute has been found for the rags. This play an important _ part in this study, _ the water stains on _ the rock being due’ “to the absence or partial absence of _ one or more forms of these lichens. _ The standing water may occur in a com- paratively short _ time, possibly in a season, but a num- ber of years are re- “quired to change ‘Substantially the sharpness of a water line once formed. One of the accom- - Panyingillustrations : -showsclearly the ap- ‘pearance of these “stains or water- Marks. It may be “Noticed that the ‘Marks are higher on “the exposed face of the rock than around the corner where the rock is protected to some extent from Wave action. The other illustration Suggests the length of time required to altera mark. On this rock a high-water mark was cut in 1895 at the point indicated by the pencil. It is still plainly visible and practically unaltered, although it is no longer the high-water mark: for that particular locality. One of the most interesting series of water-marks left by large inland bodies of Water may be seen on rocks which now lie far above the level of Great Salt Lake. These rocks tell the story of the lake’s gradual evaporation. On the rock shown in the illustration at the top a high-water mark was cut in 1895. In the oval appear water-marks and _ stains substitute is waste tanbark. In the manufacture of wall- paper alone fully eighty per cent of the rags previously used are being suc- cessfully replaced by it. The greatest total saving that tanbark is effecting, how- ever, is in the pro- duction of felt shin- gles for roofing. The United States has been manufacturing nearly nine million square feet of these shingles each year. The material enter- ing into them weighs about two hundred and forty thousand tons. Of this, by far the greatest part has been made of rags. But now over thirty per cent of this is being re- placed by the tan- bark, and the fin- ished product is as satisfactory as_ it ever was. The tanbark is made up of the bark of oak and hemlock trees. Some seven hundred thousand tons of it had been going to waste each year. But now, after the valuable tannin has been extracted from the waste, every scrap of it is being put to this new usage. Even the worn-out tanbark flooring used in riding academies and for exhibition purposes may be used again in this way. It would seem then that felt shingles for roofing would be one of the few manufac- tured articles the price of which has not been augmented by the war. 596 Popular Science Monthly “WARNING” sign about three by four WARNING! feet is erected on temporary standards about a. street block apart along the — - thoroughfares which are to be improved, willbe granted and as far in advance of actual paving Famed h. Preston, THis STREET W: work as is possible. These signs are painted in large white letters on a bright red background as follows: WARNING! THIS STREET WILL BE PAVED! All underground structures, gas and — water pipes, etc., must be put in at once After completion, no permits to cut — will be granted for five years. James H. Preston, Mayor. By the strict enforcement of this regula- tion, city officials have convinced contrac- tors that they are in earnest. in thei . determination to make one cutting up of a This warning is placed on all streets to be . street the limit for necessary installations. paved, as far in advance of the work as possible } j How Baltimore Protects Newly Paved Quartering Potatoes for Seed with a . Streets and Saves Time and Trouble New Double-Blade Cutter 4 ALTIMORE, Maryland, has adopted VERYBODY knows _ that potatoes and proven entirely grow from the ‘‘eyes’’ cut from other potatoes. But only a farmer knows how to cut the eyes so that the largest and healthiest potatoes are ob- tained. Even he can stand improvement in his methods of cutting. Nine farmers out of ten use an ordinary single- blade ‘“‘potato” knife. But the cutter shown in the photograph will double, and even treble, the speed of cutting. 4 This cutter has a double- edged blade held verti: cally in front of the opera- tor. With the horizontal guide below it, the blade is securely held in position by steel bracing which is attached to the iron board upon which the operato: sits. A potato is taken in both hands and pushed sharply against one of the edges of the knife. The smaller of the severed pieces is dropped into the practical a system which reduces the number of “‘cuts’’instreetsand which has eliminated the tearing up of new pave- ments for the laying of gas and water mains or services, sewer pipes, con- duits and the like at different times. Ist. A list of streets ‘to be improved is adver- tised in the daily papers four times within a period of six weeks. 2nd. This list is sent to all city departments and to all public service corporations operating within the city limits. 3rd. A printed form notice is served on each owner or leaseholder of property abutting on streets to be paved. This form contains some good advice on “‘Before,”’ “‘Dur- iy BLADE SHARPENED ON ALL EDGES ing’ and ‘After’ paving a ee ee basket, while the rest i operations. halves the potato, and the pulled ‘back against the 4th. A conspicuous backward stroke quarters it other blade, to becutagain. > 4 Nature Hides a One Thousand-Pound Stone Tomahawk in a Coal Mine HE biggest and sturdiest toma- = hawk ever seen is on exhibi- tion in a little town in Western _ Pennsylvania. It was not _ fashioned by an Indian _ “brave’’nor by the hand of any man, but was made by _ Nature herself of solid rock. A coal miner, dig- ging away in the bowels of the earth, came across the natural curiosity and with the help of his fel- low workers brought it to the surface. It is composed of one rock and weighs about a _ thousand pounds. When _ thequestion aroseas to the use _ to which the tomahawk could be put, it was suggested that the handle be sunk in the __ ground and the head be used as a hitching post. This was . done. The handle was set three feet in the ground and a = steel stake and chain fastened a to the top. There is no horse in Pennsyl- _ Vania fractious enough to pull it up. .Hitching a Modern Motorcycle to an Old-Fashioned Buggy needed a horse to haul a buggy, and so V. L. Snyder of Douglas, Oklahoma, = sed his high-powered motorcycle as : a substitute. Only a few minutes were Popular Science Monthly A hitching post of stone which resembles an Indi- an’s tomahawk. found in a coal mine 597 required to harness the machine between the shafts. ©The breast band of the single driving harness was’ put around the forepart of the machine and the traces hitched to the singletree in the usual manner. A short rope was provided to support the shafts and hold-back straps to keep the buggy from running over the machine when making quick stops. Two passengers rode in the buggy and two on the motorcycle. The combination prov- ed to be a decided suc- cess. Several miles of country roads were tra- versed and numerous hills were climbed without diff- culty. The four passengers doubt- less made better time and were more comfortable dur- ing the trip than if they had all been crowded into the buggy with Old Dobbin in the traces. The motorcycle proved fully equal to the horse’s job. It was Some Curious Fires Which Extin- guished Themselves FIRE in a church in Boston, Mass. melted the lead water pipes in the storeroom where it started, and the water gushed forth as from the firemen’s hose. A manufacturer of metal pails, The motorcycle not only drew the buggy over hill and dale but carried two extra passengers with ease with an establishment in Phila- delphia, has his conscientiousness to thank for saving his plant from a fire recently. His orders were that all finished pails be filled with water and left suspended from the ceiling for a time in order to test them. During the noon hour one day, while the men were at dinner, fire broke out in the testing room, heating the upper portion of the room to such a degree that the solder of the bails connecting the pails melted and the pails dropped, splashing water all over the place and putting out the fire. Popular Science Monthly Harvard’s varsity crew practicing on their indoor river course in the rowing tank at the Newell Boat House, rowing hard against a current produced by a gasoline motor Training Harvard’s Crew on an Artificial River with a Real Current HEN it is impossible for the members of Harvard’s crew to practice on the river, the men are taught the art of rowing in the tank at the Newell Boat House. To make the indoor practice as similar as possible to actual rowing conditions on a river, a stiff current is set up in the tank by propellers operated by a gasoline motor. Indeed, rowing in the tank of moving water is harder than it is on a river with a strong running tide, because the boat is stationary and the water moves in the same direction as the stroke is taken. The boat is thirty- eight feet long and has sliding seats. bead Converting an Automobile Into a Farm Workhorse N attachment recently placed upon the market by a manufacturer in Tacoma, Washington, enables the farmer who owns a small automobile to convert it into a tractor and back again into a pleasure car. To convert the automobile into a tractor the body and mudguards of the machine are removed, a small pinion gear is applied to the axles in place of the rear wheels, heavy steel tractor wheels are substituted for the automobile wheels, clamps a steel rim six inches wide is placed on the front wheels after the tires have been removed, as illustrated below. dee By removing the body, mud guards, rear wheels and front tires of the pleasure car and substituting tractor wheels and a small pinion gear in their place a farm tractor is created and by means of Se en ee SS eS ee a ee ee a ee ee ee eee eee eee eee ee ee Popular Science Monthly Safeguarding Open Drawbridges by an Automatic Car-Stop TAPERED SLIDEWAY, Y BUMPER : (CONNECTING ROD CAR RAILA, BUMPER SLIDES CAR RAIL SPRING SHOE7 Diagram of the safety-stop bumper. placed at the end of the approach to the bridge and when not in use lies flat on the track It is RAWBRIDGES ‘which have been opened too quickly have caused many _ fatal accidents. Only recently accidents were caused in this _ manner in Boston and _ Chicago, where ineach ; - case trolley cars that - could not be stopped in time plunged _ down into the water. Some type of safety- stop should be provided on every draw- bridge. That it is perfectly feasible to provide such stops is proved by the ac- companying photograph which shows the type of stop now being used on a bridge having an upgrade approach. It is the de- sign of a Chicago engineer, J. B. Strauss. The Strauss safety-stop is placed at the end of the approach to the bridge. When not in.use, it lies flat on the bed of the track. But just as soon as the bridge is opened, an electric motor is automatically started which swings the front end of the striking-frame around on its pivot, until it is raised about two feet above the track. The heavy pivoted end of the heavy steel structure of this frame is held se- curely down. Acar which strikes the frame can get very little nearer the edge of the approach than the front of it. In all ordinary cases, the collision will not be severe and the bump will certainly be pref- erable to a_ plunge into the river. A push of the thumb operates the hammer on this Chinese typewriter and moves the spacer 599 As soon as the bridge is opened an electric motor is automatically started which raises the bump- er into position It Takes Four Thousand Characters [to Typewrite in Chinese MECHANICAL engineer of Shanghai, China, has invented a Chinese type- writer with a revolving cylinder about six inches in diameter and sixteen inches in length, on which four thousand of the multi- tudinous Chinese characters are distributed over an ordinary matrix. The ‘‘keyboard”’ consists of a flat table surface upon which are duplicated the type characters. To write the letter ‘“‘A,’’ for instance, the pointer at the end of a rod attachment is placed directly above the character as it ap- pears on the flat table keyboard. Then a hammer is dropped on a plunger and the impression is made. Several carbon copies may be secured. Therod attachment which locates the characters on the keyboard also turns the type cylinder and moves the car- riage. The machine weighs about forty pounds, It’s Sheer Weight That Keeps a Pier in Place Here is an inexpensive way to get the necessary amount ba 1 t ij 1 { is ‘ ‘ ' 3 1 ' Boos ' ee | a The new type of pier instead of being cast into a solid block is made in the form of a hollow semi-circle the ends of which are extended backward in the form of two parallel walls NLY a few years ago, () the piers which sup- ported the shore ends of a highway bridge were made of huge, massive blocks of concrete. The sheer weight of the con- crete steadied them and prevented their slipping away or overturning with the bridge into the river. Upon this principle of op- 203327), TRESTLE Hine ~~, BRIDGE SEAT DOWNWARD SLOPE OF e ABUTMENT TO CONFORM WITH EARTH FILL “CONC ABUTMENT REINFORCING RODS = ABUTMENT PROJECTION COVERED BY EARTH Plan of the new type of pier. The convex face of the semi- circular wall faces the river Instead of casting the piers into a solid block, those of the new type are being made more in the form of a hollow semi-— circle. The ends of this semi-circle are prolonged © backwards in the form of ~ two parallel walls. The convex face of the semi- circular wall faces the river. ~ A wide rectangular-shaped — eration, however, these piers could never be made too large. Indeed, the danger lay in possibly making them too small. Evidently, they were very expensive. No wonder then that engineers have been giving the problem of the highway bridge much attention. The result has been most satisfactory. An American engineer has lately brought out a highway pier which works on a more scientific principle. His pier, illustrated in the accompanying photo- graph, is just one half as expensive as the older types, while in some cases, it has even proved better and stronger than they could have been. notch is left at the top of © The land-end ~ of the bridge fits into the bridge-seat thus ~ formed. The prolonged ends of the pier 7 this part, directly in front. slope downwards away from the river. The piers are made a foot thick all” around. A number of heavy steel rods are These — rods run nearly parallel with each other” around the piers as shown in the diagram ~ they greatly reinforce the entire” Earth is dumped into the pier — The two extending walls are then deeply buried in It is the weight of this earth -which prevents the pier from slipping.” 600 cast in the concrete of each pier. and structure. to fill up the hollow inside. earth also. or vl _ cycle to make a belt ————————————— Dynamo Lighting System for a Motorcycle Winner of Third Prize in Contest HE modern automobile with its self- contained electric plant is much envied by the motorcyclist, but electric lights are equally possible for the motorcycle, with the dynamo in the illustration. Take a rim of an old bicycle wheel and bolt it on the rim of the motor- drive for thedynamo, which is fastened on the luggage-carrier supports. The dy- namo used on the motorcycle illustrat- ed was a discarded one taken from the ignition system of an automobile. The headlight used car- ried an 8-volt, 12 candlepower bulb. In running from 4 to 40 miles per hour a good light is pro- FOR PRACTI ICAL WO RKERS cared for will give excellent service. In principle, a clutch consists of a number of disks contained in a _ circular~ casing. Every alternate disk is secured by projec- tions around the periphery which fits in grooves in the casing. On the outside of this casing is mounted a sprocket connected with the motor sprocket by means of the short drive chain. The counter- shaft, by means of which power is trans- mitted to the rear wheel, extends with- in the clutch casing and carries the other alternate disks by means of projections on the central hole of these disks. Strong springs are used to clamp the disks integrally to- gether when driving, and a screw-operat- ed thrust bearing is used to compress the springs and free the duced. When not The dynamo mounted on the luggage-carrier disks when theclutch running, a switch is supports is driven by a belt from the rear wheel is thrown out. Two used to turn the cur- rent on from the battery. The battery consists of 4 cells of dry battery placed in a box that is bolted on the braces of the lug- gage carrier.—DaAvip W. FREYE. Things to Know About Your Motorcycle Clutches HE clutch, the intermediary between engine and rear wheel, has been to many motorcyclists more or less of a mystery. Indeed, some of the early clutches were weird and wonderful. How- ever, modern motorcycles are equipped with clutches which if properly used and general types of clutches are in use—the dry plate employ- ing steel surfaces in contact with raybestos linings, and the grease or oil lubricated steel on steel clutch. With proper usage, the dry clutch should not require new raybestos linings oftener than once a season. When polished and dry, the linings may be improved by the application of glycerine. As the linings wear down, the copper rivets should be inspected carefully to see that they do not project above the surface of the linings. If the rivets do project too far, they will come in contact with the steel plates and cause the clutch to become harsh and jerky. The 601 602 rivets should be hammered with a punch below the surface of the raybestos. The only additional attention required is oc- casional lubrication of the bearings, and tightening of the screws which regulate the spring tension, to compensate for the grad- ual wear in the raybestos linings. The all-steel plate clutch requires packing with some lubricant at intervals. For this, the plates should all be removed, wiped off and greased with a thin coating of heavy grease into which a generous quantity of flake graphite has been worked. Flake graphite will be found to adhere longer to the disks than the granulated form. The all-steel clutches may be made much more flexible and smooth by substituting molded raybestos disks (obtainable from almost any motorcycle dealer) for some of the steel disks. not secured in any way and merely serve as floaters or separators to keep the steel plates from sticking together. The usual steel disk clutch contains from eight to eleven steel disks. If four steel disks are eliminated and two-raybestos disks added, the clutch will be made very smooth, jerk- | ing will be eliminated and the clutch will seldom require lubrication. A tight short drive chain is a frequent cause of clutch trouble, throwing an undue strain on the bearings. Unnecessary tight- ness of the chains also breaks the rollers, stretches the chain and wastes power. . Several troubles are encountered with steel disk clutches used on some of the 1913-1914 motorcycles. In these clutches, the spring tension is regulated by screwing in-a plate which forces the springs against the clutch disks. The central threaded hole in this plate is about 3 in. in diameter and the thread is the fine motorcycle 24 standard, and screws on a shaft extension or hub. After the clutch has been taken apart a few times, the thread becomes worn and it is impossible to screw on the plate against the spring tension. The usual method of serewing this plate on by means of a hammer and punch or blunt chisel is not conducive to thread conserva- tion. With the usual number of disks (8) this clutch has an excessive amount of surface. If a couple of disks are left out, the clutch will work as well, and it will enable the plate to be screwed in on good threads which will hold against the spring tension. Another trouble is in securing the control clamp to the thrust-bearing collar. Rough- ing the thrust-bearing collar on an emery Popular Science Monthly These raybestos disks are » wheel or inserting a piece of emery cloth underneath the clamp will be found to prevent this from slipping. Continual slipping of the clutch which does not respond to tightening of the springs is generally due to the springs being weak. The remedy is new springs. — In adjusting the clutch controls, be careful not to have the thrust- bearing sO tight as to prevent the clutch from going all the way in. When the clutch is in tight, there should be some play in the bearing. Always leave the clutch in when the machine is not being used. If the clutch is" left out, the springs will soon lose their tension.— WESLEY G. PAULSON. New Clay Pigeons That Break with a Single Shot HERE is probably nothing more ex- — asperating to the expert trap shooter — than to know that he has struck a flying © target and yet to see it soar gracefully away — as if no shot had touched it. Aclay pigeon — has been brought ~ out that will do — away with such — an annoyance, 4 for it will break — if hit by but.a — single shot. a In making these pigeons the inner part 4 is chilled suddenly from a heated condition. — This tends to make them very brittle. — The material used is a species of glass, al- — though the finished product is still known — 3 as a clay pigeon.—H. C. RIDGELY. : a l ite mi PET CHILLED INNER SURFACE The strain causes the clay to break easily a ae An Alarm Clock for Awakening the Deaf AVING been awakened by a light E suddenly turned on in his room, a — deaf man devised an alarm clock to arouse him each morning by this method. An — ordinary alarm clock was purchased at a © department store and electrical attach-— ments were made to turn on the current for ~ the light. A high candlepower light was — hung from a pull-switch socket placed near ~ the sleeper. The clock is wound and set ~ in the same manner as any alarm clock. © Attached to the winding key is a spool on which is placed a cord. The loose end of — the cord is tied to the pull-chain of the | electric socket. When the time arrives for sounding the alarm the revolving key and — spool take up the cord and thus turn on — the light.—FREDERICK J. KNos. 3 A Small Filter for Light : Hee Machine Oils >: -\ GREAT many differently constructed _ £\ practical filters can be made for light _ machine oils, where they are not circulated _ too rapidly or in a great quantity. The re- ~ sults sought in such a locally constructed de- vice are simplic- ity of parts, op- eration and oil delivery. _ The illustra- tion shows a fil- ter which is very serviceable _ where the oil is “required to be thoroughly cleaned but is not needed in a very great _ quantity. The fe shell may ‘be built from _ any tin can or receptacle of a suitable size. _ Another receiver _ of the same nature, but a trifle smaller _ is used for holding the dirty or filtering : pou. A number of strips of candle wicking or light cotton rope are thrown over the ' sides of the inner can and held to the outside by means of the looped wire strip. Through the strong capillary action of the oil and rope or wicking the _ best of the oil is raised, and drips down into the outer shell where it is drained _ off as it is wanted. The inner recepta- cle should be cleaned as often as necessary. The dimensions given are _ for a filter that was made and used with excellent results —F. W. BENTLEY. Getting Rid of the Destructive Attacks of White Ants | Sapa glgs are pests the attacks of which must be guarded against, since they may seriously damage wooden Structures, stores of food and clothing, field crops and plants. They have been own to eat out the core of a wooden beam for several feet before being discovered. Woodwork which is in con- tact with damp soil is especially likely Popular Science Monthly 603 to be infested. The ants colonize in large numbers and attention is generally attracted to them by the passing in and out of the flying members of the colony during the swarming time in the spring. Long tracks of earth leading to a section of a structure is also an indication of their presence. If in- fested timber has not been weakened _ too much, it need only be frequently drenched with kerosene; but if it has been too much eat- en away, it will be necessary to replace it with new timber. Treat- ing the new timber with coal-tar creosote will keep the ants away. If the colonies nest in the ground near the wood, applications of carbon _bisult-- phide may be used. Should stores of food and. clothing be at- tacked, the rooms in which they are stored should be thor- oughly sprayed with a 5 per cent solution of kerosene emul- sion. The cloth- ing and similar goods should be aired in the sun. Field crops and plants are liable to be at- tacked when near ground which has_ been The filter for separating recently cleared the oil from the sediment and which con- tains decaying logs and stumps. Such attacks can gener- ally be prevented by plowing late in the fall the ground in which the crops are to be planted. Should the pests appear in spite of this, the young sprouts should be sprinkled with the 5 per cent kerosene emulsion. Infested trees and flowers should be treated with the solution in the same manner. 604 Drawing Outlines for Forming Scrolls on Ionic Capitals HE secret of the beautiful curves of Ionic architecture is said to be trace- able to a seashell. The skillful artist fastened a string to the stylus and then wound it about the shell from the top to the bottom. The shell used was in the form of a top with a spiral groove running down its side. The point was placed in the center of the proposed scroll and the mark was made with the stylus, pulling at the same time on the string, which gradually unwound from the shell and released an ever lengthening radius. for the stylus to work in. This produced a The method employed in forming Ionic scroll- curves with the aid of a periwinkle seashell scroll with an accurate and_ beautiful curve. Various types of scrolls were produced, according to the size and shape of the shell—Haroi_p V. WALSH. Marking Date of Repairs on Auto- mobile Tires OW can I mark my repair work for future identification? This is an oft- — repeated question that comes from repair- men who have tried many systems. Here is a scheme that has been found very effi- cient: A tin strip, 1% in. wide and just long enough to make the necessary figures, is stamped by a machine that punches the letters in backwards. This strip is placed against the uncured rubber, with the em- — bossed side of the tin turned out. When — the job is cured the tin strip is peeled off — and the rubber is found to have been forced — into the little grooves of the letters, forming a perfect mark. The average repairman might find such a punching machine a little too expensive for his requirements, but by — providing himself with a set of letter punches, which as a general rule are inex- — pensive, with a hammer he could make a few of his own strips. . { Probably the best place to mark a tire © repair job is close to the bead. The re- pairman might save labor if he punched his — initials on a separate strip, for then strips — with just the dates could be made up each morning as needed. ; Popular Science Monthly | . F : Re-Shellacking a Cork-Float on an Automobile Engine HEN re-shellacking the cork-float of a carbureter it should be first carefully — sandpapered to remove all particles of the old shellac. If this caution is not observed, — additional weight will be added to the float — which will necessitate a readjustment of | the carbureter. This may seem unimpor- tant, but it will result in trouble when starting the engine. A very slight change — in the weight will cause considerable differ-_ ence in the amount of gasoline admitted — and unless the reason is known it is hard to locate the trouble. 4 Tea Kettle with Whistle in Spout for a Signal HIS kettle has no detachable top but it — is provided with a generous spout through which it is filled and emptied. Attached to the ; handle by a chain is a small signal whistle which is slipped into the spout N to announce the : é boiling point. i ill There is possi- ill bility of a small a fuel economy due to the scarc- ity of vents and the undoubted advantage of having no cover to slip off during the pouring operation. Tea kettle which is filled and emptied through spout field of usefulness of the motorcycle. =. LTHOUGH any kind of a shed will do to house a motorcycle, the portable garage here described possesses many advantages over the simpler type of struc- ture. The initial cost is small, and as the __ building need not be much larger than 6 by _ ‘I2 ft., it can be put on a small back lot or _ at the rear of an apartmént-house grounds. The cost of the material will, of course, _ vary in different parts of the country, and the owner will us The Motorcycle _By BM Ikert This article won the first prize of $25 in the Motorcycle Contest which closed December 30, 1916. Hundreds of ideas were sent in on the repair, upkeep and The Popular Science Monthly bought - the best ideas and will publish them during the course of the year.—EDITOR. used for the roof which is then covered with roofing paper. One window is provided, and this is hinged at the top so it can be swung up and hooked on the rafter, while the doors, each one of which is 2 ft. wide, swing outward. About the first thing to do, after having selected the building site, is to procure six large flat stones and place these as shown, one at each corner and one in the center on the sides. A = A _ save consider- ne te LA x rectangular _ ably if he does Y It a frame should _ the work him- eS [2] ibaa — | now be made self. The gar- ec? ibs y measuring 6 by age shown cost, = +t 12 ft., outside _ together with it ; Wey dimensions. paint eer This frame is _ ware, about a cas = : made of 2 by 4- i mE TS a ae pn . . a $30; but the HOW THE SIDING IS NAILED in. scantlings _ owner did the iron SS 9 and should _ work. From all PLATE I have two joists e parade “tana ents) 2 IRON running paral- SF - > = > P a “ basing. nec FLOOR PLAN CopNeR DETAIL ee “nent Structure, CONSTRUCTION DETAILS | about 24 in. but it can be — ‘+1 apart. See that taken down in about an hour’s time. It is made in seven very easily adjusted sections, comprising the floor, two sides, two ends and the roof, which is made in halves. The sides and ends are covered with drop-siding, while ordinary boards are End and side elevations with floor plan and detail of corner and roof for making a motorcycle garage the frame is level and rest- ing on all the stones, which should, of course, be level. Next cover it with the floor boards, which can be plain or matched, the latter making the better job. Trim the flooring flush with the outside of foundation frame, and this 605 606 will finish the first unit of the structure. The framework for the sides and ends is made of 2 by 3-in. stuff, which is ample for so small a building. The ends are made up first, and these should measure 6 by 6 ft. As will be noted, the front end frame con- sists of four uprights nailed to two 12-in. lengths at the bottom, and crossed at the top by the plate. The 4-ft. space between the inside studs forms the door space. For the rear end all that is required is a frame- work 6 by 6 ft. built as shown, with a single stud placed in the center. When both ends have been finished they can be set up on the floor and secured to the latter by lag screws. It will be seen that Popular Science Monthly the ends. The proper method is shown in the upper left-hand corner of the floor plan. The siding is carried to the top of the plate — on the sides, but at the ends it must be © built up about 1 ft. higher. In doing this, nail on short pieces, marked A, of the 2 by 3-in. stuff, to the end plate. It is not neces- sary to cut these to the exact height as yet, but make them about 1 ft. long. Now carry the siding up to cover these pieces and proceed to trim it to the rounded shape shown. Procure a stick about 7 ft. long and drive a nail about 1 in. from one end © and another 6 ft. 10 in. from this. Drive — the first nail into the floor exactly in the — center of the © doorway and these screws ex- tend down through. the floor and into the2 by 4 pieces below, insuring rigidity to the structure all through. To get out the framework for the sides, practically the same procedure nail protrude — slightly. Using | the stick as a © sort of beam — compass, let — the nail des- — cribe part of a | circle on the © top. Drive an- | other nail 5 ft. — circle or first — is followed as nail, and this — was used for The side in which the window is placed. Two windows will give the 4 the ends. The may be used but one is sufficient for a small building shape of the — top and bottom members are cut to 11% ft., and five studs are placed as shown. The two sides are identical except for the window, which is placed on one side only. However, if desired, a window can also be placed on the other side. The size of the window is determined by the builder, but it will be found that one measuring about 16 by 40 in. is large enough. Set the two side frames between the ends and fasten with lag screws, as was done with the ends. At the top, the ends and sides are fastened together by means of angle irons, as illustra- ted in the detail drawing. For the siding, ordinary boards could, of course, be used, but if a particularly neat looking job is desired, drop-siding makes an excellent material. This can be placed before the roof is put on. First, see that your framework is square and plumb, then beginning with the bottom board, nail the siding to the studs. Let the boards on the ends extend over those on the sides, but be careful not to nail any of the side boards to top of the door | opening. If the siding at the top has been ~ nailed only temporarily, it can be taken ~ down and the curved line cut more easily. — To get out the rafters B, tack a board at — the top of one of the ends and draw a line using the same radius as was used at the ~ top of the ends. Cut ten pieces for the — rafters, which are notched to fit over the ~ sides and fastened in the center with cleats, — as shown. In fastening: the cleats, use — screws, so that when the building is taken — down, the screws on only one side of the ~ cleat need be removed. Set the five rafters — as shown and fasten them by cleats to the © studs, using screws as before. Nail the ~ roof boards on, letting them extend over — about 5 or 6in. These should be so placed ~ that two of them form a joint at the center, — running the entire length. Cover the roof with one of the many roofing materials on the market and run a knife along the top central line, thus dividing the roof into two — parts. Next cover the joint with a thin batten, held down by screws. let the other — 10 in. from the ~ center of the | dimensions shown, using the same kind of ‘material as was used for the siding of the * ilding. By nailing on the curved facial boards to the ends and those on the sides, gether with the corner boards, a neat looking building results. The boards fitted al the top of the sides must be matched to - the projecting rafters. Care must be taken to nail the corner boards as shown, and in fitting the quarter-round molding, nail it to only one of the boards. Then when the ends and sides are taken down, the molding will come with whichever board it was nailed to. _ From the foregoing description, it will be noted that the building can be taken down ve y easily and in a comparatively short time. If it is desired to do this, the thin atten on the roof is first taken off and the sc ws on one side of the cleats, joining the afters, taken out, the cleats remaining to the other rafter piece. Then remove the cleats holding down the rafters to the studs. -The roof can now be lifted off in two sections. Next remove two of the screws in the angle-irons which hold _ the ends and sides at the top. Only the lag screws at the bottom now remain to be out. A sloping runway is built at he front, resting on several large stones. nxACC Y taKe Marking an Automobile for Positive Identification SUAL marks of identification on auto- \/ mobiles can be easily obliterated and a jopular make will be difficult to claim. dere is a method I have used for marking s, and it eN vile so that —pscecoe tron smss tees \ car may — WM IDENTIFICATION nam A auc Stamped metal strip inserted in hole drilled in the frame netal, preferably brass, is stamped with ‘the owner’s name, or other inscription, then rolled up closely and slipped into a hole drilled in the frame in some out-of-the- way place. The hole is then plugged and hed over so that it cannot be seen. owner can easily locate the place and show conclusively that the car belongs to him.—C. A. JOHNSON. 4 re. Popular Science Monthly The door is made in two parts, of the — 607 A New Combination Triangle for Draftsmen’s Use HE illustration shows a triangle com- bining several unique features of value to the draftsman. In mechanical drawing two lines are generally laid out first; namely, the vertical center line and A triangle with éoishihatiaees ‘ek serve for various tools other than the ordinary one the horizontal center line. If a line is wanted parallel to A and 2 in. to the right, the triangle is shifted. along the T-square to the position as shown. By running the pencil along the vertical edge of the implement the desired result can be obtained. If the line is wanted 2 in. to the left, instead of to the right, it would simply mean shifting the triangle along the T- square in the direction of the arrow C until the 2-in. mark on the right horizontal scale is flush with A, then by running the pencil along the vertical edge of the implement the line wanted can be drawn. The same principle can be employed when measuring below the horizontal center line B, using, of course, the upper edge of the blade. An Emergency Clothes Hanger Made from Roll of Paper HEN traveling or visiting, one fre- quently is so situated that a clothes hanger is not available. A good substitute may be made in a quick and simple way. Roll up a newspaper loosely and tie it in the middle with a piece of string, leaving a loop by which to hang it. This may be suspended from a gas bracket or from a handy hook.—JENNIE E. McCoy. 608 A Novel Waste-Basket with a Drop Bottom HE pyramidal shape of this waste-— basket guarantees it against upsetting, even when bulky newspapers project from its top. The solid construction will hold the pipe-ashes and dust until it becomes necessary to dump them, and then the bottom may be unhinged and emptied completely by pulling the catch, so that it is not necessary to use the hands to take the papers out. If made of quartered oak, cypress or even of yellow pine, stained so as to bring out the grain, such a basket can be made an ornament to any room. It may be finished in any style. The essential parts of the basket are the four sides and the bottom, the sides being of 4-in. material and the bottom, either of the same thickness or of I-in. lumber. sores Seema | Waste paper basket with drop bottom. Details and dimensions for its construction Two of the sides are 18 in. wide at the bottom, tapering to 8 in. at the top; the other two are I in. narrower. These sides should be securely nailed together, as there are no inside supports. The construction is strong enough, however, for the purpose of such a basket. If the work is well done, with the nails countersunk and all holes and cracks puttied before staining, the joints will not be visible. The effect of the legs may be obtained, if desired, by cutting out the bottoms of the sides with a compass- saw. After nailing together and sandpapering the whole, the stain may be applied. If it is desired to bring out the grain, apply the stain over only a small portion at a time. Allow it to set for a moment and then wipe off the surface with a dry cloth. The resulting tone depends on the time that the stain is allowed to stand and the amount of wiping done. When the stain has dried, the piece may be finished by rubbing with wax in the usual manner; or an almost away and that a crack large enough to: Popular Science Monthly equally good effect may be obtained bya applying a coat of flat or mat varnish. When the piece is. thus prepared, the bottom may be fitted. It consists of a_ board a trifle less than 17 in. square, preferably with all four edges beveled to the - same angle as the sides of the basket. Push this piece in from the bottom until it fits snugly, and mark the level on both sides of the basket. Remove it and attach hinges to one side; then replace it in the same position and fasten the hinges tempo- 4 rarily to the side of the basket.. Placed in this way the bottom will not turn percentages. - € s a : A Rabbit Trap Made of Ordinary a « ‘ Drain Tile ~ AV CLEVER plan for catching rabbits is LX recommended by the Department of Agriculture. It is a trap which catches the . ral bits alive, and almost any boy can con- ‘struct one quickly. : _ The materials required consist of a 12-in. , ; . PF Y L/ The tiles are set in the earth so that a hiding-place is made for the rabbit | sewer-tile with a 6-in. side outlet and two | Ke of 6-in. tiles. The long end of the ee tile is set downward in the ground so Be — Popular Science Monthly 609 that the small side outlet is below the sur- face, as shown. The two small tiles are connected with the side outlet so that the opening will extend out to the surface. The tiles are well covered with soil to exclude all light, and a close fitting cover is placed over the upper end of the large tile. The open end of the small tile may be sur- rounded with a few small stones and brush to make it inviting to the rabbits. The rabbits are free to pass in and out of the dens thus made. When they are located in one of them it is an easy matter to close up the entrance and take them out of the large tile by raising the cover. Such traps are especially. suited to open places or on prairie lands where rabbits cannot find natural hiding-places. A Wall Book Shelf of ‘‘Built-in”’ Appearance ILE almost any kind of wood can be used in the making of this book shelf, it is well to select the kind of wood that will match with other pieces of furni- ture, or the finish of the room. If made of the same wood as the doors and casings it will have a “‘built-in’’ appearance and there will be no abrupt contrast with articles of furniture. The finished shelf is shown in Fig. 1. The material list is as follows: 1 base, 2 ft. long, 614 in. wide and % in. thick 2 facing pe,© in. long, 514 in. wide and in. I top back rail, 1244 in. long 14 in. wide and 3% in. thick 1 bottom back rail, 12% in. long, 1 in. wide and % in. thick 2 top end rails, 6 in. long, 1% in. wide and 3 in. thick 2 bottom end rails, 6 in. long, 1 in. wide and % in. thick 2 back uprights, 10 in. long, 114 in. wide and 3 in. thick 2 brackets, 6 in. long, 2 in. wide and \% in. thick To start the work, begin with the base, the plan of which is shown in Fig. 2. If the material is purchased from a mill the pieces can be ordered cut to dimensions, planed and sanded, which will cover most of the hard work. The outside corners of the base are slightly rounded as shown. The bracket pieces and the back uprights are next in order of construction. The lower ends of the uprights are cut pointed and set in the back edge of the base as shown in Fig. 3. The joints for the rails are shown in Fig. 4. The facing pieces have an ornamental 610 opening cut in them. It consists merely of four circles cut out*as shown in Fig. 5. These may be drawn with an ordinary pair of compasses. The outside edges of k—6" ve I'd FIGS Details and dimensions of a book- case and shelf for a small clock these pieces have their upper corners rounded and the bottom part cut out to form a projection that gives it a pleasing appearance. These shapes are drawn as designated in Fig. 6. They are then fast- ened to the base with screws, Fig. 7. The brackets are shaped as shown in Fig. 8. These are fastened to the underside of the base with screws, as are also the back uprights. It is best to give the sur- face of all joints a good coat of glue before turning in the screws. It is necessary to bore a hole before driving a screw in cabinet work. This may take a little time but it saves a great deal of trouble in the end. The central division may also be used as a place for a small clock.—H. ADLON. Paper Clips with a Stick Used for Paper File HERE is now on the market a simple spring steel clip that renders it a very simple matter to contrive a satisfactory file for newspapers, blueprints or drawings. Three clips are necessary, and these are at- Popular Science Monthly tached at the center and at each end of a. slender stick of the required length. The. latter should preferably be of oak about 3/16in. by 1 in. Each clip is held in place by means of two small wire nails driv- en in through holes punched near the ends of the clips, all as indicated in the accompanying illus- tration. When not in use, the small handles may be pushed flat against the sides, leaving one remaining up in the . center so that the file may be hung up. The sheets may be filed on one or both sides of the center strip—JoHN D. ADAMs, i § clip on papers and stick Goggles to Be Used When Making Chemical Experiments PAIR of motor-goggles with windows of mica rather than glass, afford valuable protection to the eyes when experimenting in a chemical laboratory. A pair should be kept handy for use when operating with flasks and tubes of boiling liquids that are apt to decrepitate and spurt. The most comfortable to wear are those with large windows having an edging of chenille or velvet.—H. J. GRAY. : To Keep Weight of Automobile ; from Tires HE upkeep of tires is the greatest ex- pense of an automobile, but with the a 16"! — —— ——= = Es | 2," all Axle support or jack to keep weight of automobile from tires -when not in use jack illustrated the weight of the car i held off the tires, so that the wear on th Manner of attaching _ : ql . ; greatly reduced. These jacks are easily ade and they are inexpensive to build. ne size of the jack given is for a 30-in. heel. For larger wheels the height should 2 in. more than the height from the hub the floor—A. R. CoLBuRN. A Lubricator for Automobile Steering Pivots HE accompanying sketch shows a ; simple self-feeding grease-cup which _ any mechanic can assemble without diffi- — culty. This cup may be applied without any alterations to the automobile axle. It consists of a brass tube threaded at both ends and of the proper size for the pipe thread in the tapped hole of the axle. One end screws into the axle, and on the other end a pipe cap with a hole in it for e the plunger rod EY A grease-cup made of is fitted. The a pipe and pipe-cap plunger and rod . . with a light _ compression-spring are assembled as shown. This spring should not be too strong lest the grease be forced out of the bearing and wasted. = The proper size spring will make this _ lubricator far more economical than the Compression type of grease-cup. The height of the plunger above the cap indi- "gates the amount of grease which is in the tube.—W. Burr BENNETT. = ‘ SON SS hi hhh bhditi tai shitiéiidtiistitthil E Si A Soda Mixture for Quickly : Removing Varnish {4 GOOD varnish remover can be made as follows: To three quarts of luke- Warm water, add one quart of good caustic soda. When thoroughly dissolved, apply With a coarse sponge. This is much better than using oil because varnish should not be applied on an oily surface. If oil is used, it Should be thoroughly rubbed out with SOapy water and dried with turpentine or alcohol.—L. E. Fetter. Popular Science Monthly 611 A Free End Hacksaw-Blade for Difficult Work VERY handy hacksaw useful in repair work is one having a free end. Such a saw can be made from a broken Broken hacksaw in a pistol- grip to make a free end saw blade clamped in a pistol-grip handle, as shown in the illustration. The clamp part consists of two L-shaped pieces held together with bolts —JoHN W. SHANK. An Adjustable Stand Helper for the Blacksmith Shop i: Hpi usual standard form of helpers with one leg seldom gives perfect satisfaction as it is so likely to topple over when the work is pulled or pushed over the anvil. The illustration shows a different type of a helper in which there are two standards, each with two feet, mak- ing it very substantial and firm. The + a is" 24” eee By * et 3 ba 7 - a y eX A helper for the blacksmith shop that will not topple over with the work material used consists entirely of ordinary stake iron with dimensions as shown. 612 An Inexpensive Method of Coloring Electric Globes HIN a small portion of white shellac with alcohol—a sufficient quantity to cover the globe when it is dipped into the liquid. Dipping the bulb into the solution applies a coating that is a good substitute for frosted glass. To apply an even coat it is necessary to have the shellac very thin. If it is desired to have colored globes, procure some egg dye of the desired tint, dissolve it in alcohol and mix into the shellac.—GEORGE YASTE. Truck for Handling Filled Sacks on Stairways RDINARY trucks are not suitable for use on stairways. The truck shown was originally devised to remove a number of sacks filled with fancy potatoes from rooms in a basement, but it has enough merit to recommend it for general purposes. It is made up of two handles, two runners Instead of wheels two runners with both ends curved are used in the manner of a truck and three braces as shown. It can be pushed over a floor and pulled up a stair- way, preventing the wearing of the sacks or the bruising of their contents. The floor and stairway in this case were of concrete.—EDWARD R. SMITH. Popular Science Monthly How to Construct a Door-Mat of Wood Slats GOOD substantial door-mat and shoe- scraper that can be very easily and quickly made is shown in the illustration. | The crossbars are made from a number of? The wood bars are spaced for catching the mud and dirt as it is scraped from the shoes 14 by 2-in. iron rods of any desired length. and number. Each bar is drilled 6 in. from. the end with a %-in. drill. Two iron bolts. of sufficient length must be obtained and also a supply of I-in. sections of 4%-in. pipe — to be used as separators for spacing the bars. The bolts are inserted in one bar; then a I-in. section of the pipe, then another — bar, and so on, until it is complete. If the nuts are not drawn up tight so that the bars are allowed to move 4% or in., they will take off the mud much better, because they will tilt whenever the shoe is drawn across the mat.—FRANCIS W. NUENMACHER. Oxidizing Iron with Fumes from Acids ERY pleasing and durable color effects can be obtained upon the surface of iron articles by oxidizing with the vapor of acids. Having thoroughly cleaned the metal, removing all traces of grease and polishing it highly, heat it and expose it to the vapors given off by a mixture of nitric > and hydrochloric acids in equal proportions. When a good bronze color is obtained allow the article to cool, then coat it with vaseline and heat it again. A wide range of colors can be produce d after a few trials, ranging from pale prim- rose to deep brown or red. This is done by varying the proportions of the acids and © by adding other ingredients—acetic and sulphuric acids. If the disengagement of vapor is too slow the acid mixture may be™ warmed.—H. J. GRAY. = Moving Targets for a Home Shooting Gallery HE moving targets, now so common in ‘I shooting galleries, are entirely out of the question for home practice, owing to the ‘cost of the machinery and its bulky nature; ‘however, the same results can be obtained ‘with the device illustrated, which is not expensive or difficult to construct. It con- ‘sists of a board placed on a slant on two osts. On this board the moving objects ‘roll. These are made of plaster formed in ‘tin-can covers. To prevent the disks from olling off the board, strips are nailed on as hown to make a groove for them. At oth the upper and lower end, facing boards fastened so that the marksman cannot the disks until they start rolling. Details of the moving target-stand and the _ trap used for releasing one disk at a time _ A number of disks are set in the groove )at the upper end and one disk is released ) ata time by a trigger operated with a string. The speed of the rolling disks is governed | by the slope.—G. P. LEHMANN. An Expanding Bolt for a Bottle Stopper N expanding bottle stopper can be made with an ordinary rubber or a cork stopper and a bolt of the usual jexpansion type. The threaded end of an jiron screw is set in a mold and lead or Popular Science Monthly TLE $B NNN babbitt metal run in about it. The mold is made to cast a conical slug having threaded sides. The opposite end of the screw is forced through a cork or rubber stop- per and bent into a circle, asin- dicated in the drawing. When a cork is too small to fita bottle, the screw is turned and the expansion slug forces out the sides. The cork is re- moved by unscrewing the slug. Such a device er ~ = used only on bottles whic ; do not contain acids; for the =~ cad acids would destroy the metal bottle stopper screw. Sponsons for Motor Boat or Motor Canoe VERY one who has run a motor canoe or boat against a head wind must have noticed how the spray will come aboard and make things unpleasant. The following device is one I have used for a number of years with great success, and it is also of great value for fenders when running along- side a pier or landing stage. Procure from a garage two old inner tubes both the same length and size. Cut them at one point and cement the ends, or, better still, have them vulcanized. I cemented mine but I found that it was necessary to put wooden clamps on each end to keep them from coming apart. Make two snug canvas covers of 8 oz. duck. These can be easily made on the sewing machine. With a little manipula- tion the tubes can be drawn through the covers. Make a hole in the cover for the valve. The tubes are then blown up and either lashed or strapped to the gunnel of the canoe starting from the bow. Besides warding off the spray they will also help considerably in case of an upset as the air they contain would keep the boat or canoe from sinking. —B. E. DoBREE. 614 Making a Reamer from an Old Three Cornered File HEN in need of a reamer in the work- shop one that is very serviceable in an emergency can be made from an old three-cornered or a square file. Grind the faces until they are smooth; then grind the edges, as shown by the dotted | lines in the accom- panying drawing, so as to form good cut- ting edges. Fit a handle to the tang and the reamer is complete. When using a large file for a reamer it may be found hard to turn, in which case a small pipe-wrench may be used to good advantage.—JOSEPH STATLER. Corners ground off of a file for cutting edges A Successful Anti-Leak Device for Paint Brushes HE best method I have ever seen em- ployed for preventing the color or wash from running down over the handle of a large brush when overhead work is being done, is to use a sponge attachment as shown in the illustration. Take a good, large sponge, oblong in shape, if possible, { | | | \ i iy \ oe? HN il eee al ied i i \ | f i Sponge on brush handle to take up color leakage. It can be wrung out on the brush and cut a large slit in it to allow it to slip over the brush handle. Push it up as far as it will go and tie a cord on the handle to prevent it from slipping back. The sponge will take care of all the leaking color, and it can be wrung out at any time while on the brush.—JAMEs M. KANE. Popular Science Monthly - punched, to receive a nail or screw, by Replacing Old Valve-Stems in Auto- mobile Tires | ff Vass most satisfactory results can be obtained by forcing the old valve-stem — back inside the tube and cutting a small _ hole about 1 ft. from the valve-hole,, through which to draw it out. Insert the) new valve-stem through the new hole,’ vulcanizing the hole shut, and bring the new valve up through the original valve-- hole. This prevents the fabric in the valve-_ patch from being ruptured and strained, and will always hold the valve-stem secure. - A One-Piece Hanger for a Flaring Pie Tin HE accompanying sketch illustrates a form of hanger for pans, especially those not having ears or ¥ handles. The hanger is formed from a narrow strip of metal, bent into - the form of a rectangle, except that it is left open at the lower left corner, and the ends are curved backward. At the opposite side from this opening, midway between the extremities of the hanger, aholemay be either drilled or A \\\\ A\ which it may be attached to a wall. Having placed the hanger upon a wall,” it is only necessary to introduce the lip of a pan between the downwardly and hor-— izontally extending pieces of the hanger and allow the pan to fall against the wall. The pan will rest up in the horizontally extending part.—C. NIELSEN. A Quick Way to Level the Legs — of a Table ; OMETIMES one leg of a small table is a trifle shorter than the others, which causes a rocking motion when the table is touched. The difference in length may be so small that sawing the others would be a tedious job, and possibly un- satisfactory; but the trouble can be © remedied by driving a short large-headed nail like a roofing nail into the short leg.” Drive the nail up almost to the head, until” the proper length is added to the leg. HE outside diameter of the round house illustrated is 8 ft., and the 3 height is 8 ft. The unique feature is in he use of silo blocks made of clay tile to btain the shape. These blocks will make a in. wall. The tiles are laid: upon a con- = foundation that is set into the earth ft., and is 10 in. thick. A 3-5 Lixt e of cement, sand and gravel is the ‘oper one to use for the foundation and r the 4-in. floor. "The mortar for laying up the tile is made [ I part cement to 3 parts sand. If the use is built in dry sather the blocks be soaked in ater before laying them. If this precau- tion is not taken the porous structure of the s will take up the isture in the mortar d weaken its holding ities. = ow is not difficult to and plumb at all and test the wall 5" CONCRETE- ROOF SLAB \ HEAVY WIRE MESH REINFORCING 7'2" DIAMETER — uently with a ib and level during roof consists of concrete slab rein- I foeced with heavy wire \mesh. The ordinary mesh wire used for making a fence for hogs will answer the /purpose. It may be made on any level \platform, or a barn floor. To make the \slab 5 in. thick and about 9 ft. in diameter, | sack of cement, 2 cu. ft. of sand and 3 cu. An elevation of a round sciatica constructed of silo blocks of clay tile set om a concrete foundation W-E-Frudden ft. of gravel will be aes The wire mesh is laid on a layer of concrete I in. thick, then the remaining concrete is put on and tamped. The round shape of the edge can be made by means of thin boards bent to the circle, or a strip of sheet metal that is 5 in. wide. The door for the structure is the only opening in the walls. The door-frame is made of 2 by 6-in. planks, strongly fastened together and bonded to the walls. The bonding may be accomplished by driving large spikes through the frame material and into the mortar joints. The materials neces- sary for the house are as follows: S CLAY TILE WALL 5% barrels of cement 130 hollow clay building tiles, 5 by 8 I2 in. 60 sq. ft. of wire mesh 1 door frame, 2% ft. wide and 7 ft. long 1 door The square house is a little more difficult to build. However, the added feature of an outside fire box is suffi- cient recompense for the extra time and ex- pense in the construc- tion. The building is square with 8-ft. sides and an 8-ft. wall. Con- crete blocks instead of the tile blocks are used for the walls, the foundation and the floor being about the same as for the round house except in shape. The ma- terials necessary for the construction of this house are, 24 sacks of cement, 3 yards 615 616 of sand, 5 yards of gravel and 200 concrete blocks. The roof for this house is one concrete slab. No doubt this can best be con- structed by mak- ing a form within the building of the desired shape and putting on the concrete the same as was done in making the other one on the barn floor. It will require some in- genuity tomakea form for the edge, however. Nail boards together in an L-shape, making four pairs of them and form- ing a huge frame around the upper part of the blocks of the wall and properly support- ~ ing it, to form the proper eave for the roof. For either house, use ventilators in the but the post was raised and the work center of the roof slab. These should be was satisfactorily completed without — put in when making the slab. Popular Science Monthly Shoring up a Porch-Post to Repair Floor-Boards 4 AVING to repair some floor boards under and about a porch-post it was necessary to es 5 6 shore up the post. This is the meth- | od I used. I first 8 in. wide on the ground and with a trifle hee ; than the distance to the plate of the porch, I made a slanting brace or support. With an iron bar hav- ing a flattened end I raised the post up a little at a time by lifting on the end of the plank and push- ing it to a more vertical position. This was not much of a job, The curve of the walls of this house is obtained by using shaped silo tiles. It is covered with a concrete slab jack.—A. A. KELLY. . Teo SS Pe oS yo3¢ —% cords ABY | rt = rf = , . ' SSeS SHELVES ¥ > CONCRETE FLOOR TF RP SPE. ys. 9 vise 159.7 CAD ZA = a Plan and elevation of a square smokehouse having an outside firebox, all made of concrete hollow blocks set on a concrete foundation with a concrete floor An Easily Constructed Pan for Sterilizing Dairy Utensils EN dairy utensils are sterilized by steam all bacteria and disease germs which may be upon them are destroyed and, therefore, milk and cream when placed in these utensils will keep much longer. A very efficient and inexpensive steam- sterilizing plant for the small dairy can be made as follows: An ordinary roasting-pan 20 in. long, 14 in. wide, top measurement, and 3 in. deep, is used for the steam gen- _ erator. The cover is in three parts; the _ lower part, fitting closely over the pan, is covered with asbestos, upon which is placed the upper part, the latter being the same width as the pan, but 3 in. shorter at each end. It is made as follows: A _ sheet of heavy galvanized iron is cut large enough to cover the top of the roasting _ pan, allowing a little to overlap the edge. Flanges are soldered beneath this cover so that they will meet the edge of the pan, The parts of the sterilizer for the dairy, made with a roasting pan as a base _ thus making a tight cover. A hole is cut _ in the center of the cover 114 in. in diameter and a round galvanized-iron pipe 41% in. in height and 114 in. in diameter is soldered init. The cover should then be insulated _ by covering with a piece of asbestos board §/16 in. thick. A hole is cut in the center of this piece to allow the steam-outlet pipe _topass through. Then for the upper part _ make a shallow pan of galvanized iron 14 _ in. square with sides 5% in. high. Cut a _ hole 1% in. in diameter and fit the pan _ on top of the asbestos, allowing the steam- _ outlet pipe to extend through the center hole. When the pan is pressed down close _ to the asbestos, solder it to the steam-outlet _ pipe which passes through it. Four strips of stiff galvanized iron 34 in. wide are soldered to the pan. These should extend %% in. above the bottom of the pan and should run from a distance of 1 in. from the corners to I in. from the steam-outlet in the center. A section through the cover is illustrated. is =, ™ my i Popular Science Monthly 617 In case asbestos cannot be obtained, paper may be used instead. Pack the papers tight to a thickness of 3 in. over galvanized iron and cover with another iron sheet, soldering all edges together to oat STEAM OUTLET PIPE _ (SHALLOW PAN AN SUPPO CELANGE GALVANIZED COVER Section through the cover of the roasting pan showing asbestos board used for insulation make absolutely tight seams. This will form an insulated cover 3 in. thick to take the place of the asbestos. The con- struction of both covers is very similar. The other part of the sterilizer consists of a galvanized-iron box with a removable cover, which has a handle on the top. This box has no bottom. The 14-in. shallow pan on the asbestos over the cover of the roasting-pan forms the base of the box. The sides should be made separate, I1 in. high. These should fit tightly in the shallow pan. On one side of the box at the top a wire should be attached, 34 in. from the top and )% in. from the side. The cover for the box should be made large enough to extend over the sides and fit closely. A two-burner wickless kerosene stove will give excellent results for a heater. Sterilization is not a substitute for wash- ing. All utensils should be rinsed in cold water, then washed thoroughly with hot water and washing powder so that they are well cleaned before sterilization. Water at the depth of 1 in. in the pan will furnish steam at a temperature of 211 deg. F. for about 50 minutes. If the sterilizer is operated for a long period, water should be ~—— LAYER OF id “BRACES” The same construction of a cover for the sterilizer with paper used instead of asbestos added to make up for loss by evaporation. The temperature of the steam as it comes from the outlet pipe must be at least 295 deg. F. and preferably 210 to 211 deg. Cans, pails, covers, and _ strainer-cloths must be steamed for fully 5 minutes. Longer steaming will do no harm, but it is 618 not necessary. The 5-minute period must be reckoned from the time the can is placed inverted over the steam outlet, and the steam must be at least 205 deg. F. when the can is placed in position. An 5 See 2 Gi {- i Sterilizer on a two-burner kerosene stove with can in position for sterilizing utensils aceurate thermometer, with a scale reading to 212 deg. is necessary. Repairing Gasoline Pipe with Oiled Paper OME time ago I took my long-used motorcycle and started out for a day of pleasure, supposedly. I had my rifle and a lunch with me. When riding over a particularly bad stretch of rocky road, I took a ‘“‘spill,’”” but soon picked myself up, only to find the oil running from the tank. My machine not being equipped with footboards, the small oil-pipe running from the tank to the pump was exposed and this pipe had been so badly damaged by the “spill” that it was broken in two places. Stopping the flowing oil with a small plug, I decided that I was to enjoy a 6-mile walk to town. After some thinking I took some of the wax-paper wrapped around my lunch and started to piece out the broken space. I rolled the paper tightly around the ends of the pipe and wrapped it with a small roll of insulating tape which I had with me. After the motor was run a few seconds to suck the air out of the pipe, the oil started to circulate and I was able to get home without walking —DuNcAN DILLON. A Practical Wagon Trig Operated from Driver’s Seat HE device illustrated is a substitute for a wagon brake and consists of a hard wood trig A, not larger than 3 in. Popular Science Monthly square and ' ‘ : ‘ ' ‘ } 1 WRIGHT) GROUND PLAN FOR iE SPRINT START» = ' ’ Ground plan for placing the feet, knees and hands to make the start for a sprint ____ It is customary for four to six athletes to _ ran ata time, the first four belonging to the _ first “heat,’’ the second four to the second heat, etc., until all have run. Then the _ first two of each heat run additional heats, called ‘semifinals,’ after which the first _and second of the semifinals run in the - final heat. Before the meet the games com- _ mittee draw the runners’ names by lot to _ determine which ones are to be in each heat. These positions are published on the pro- gram and cannot be altered even though only one man appears to run in a heat. _ The starter oversees the drawing for the places and the clerk lines them up. The runners then dig holes in the track for their feet, the holes being 3 or 4 in. deep with a firm perpendicular back wall. The front hole is dug for the left foot from 4 to 6 in. back of the starting line (sometimes called ‘‘scratch’’). The rear hole for the right foot is dug a little to the right and far enough back so that when in a kneeling ode the right knee comes almost to the ront hole. At the starter’s command, “Get ready,” or “On your marks,” place your left foot in the front hole, kneel on the right knee, place the right toe in the rear hole, place Winning an Athlete’s Laurels I—Running, hurdling and relay races By Albert B. Wegener A technical instructor and director of athletics of twenty-seven years’ experience the hands on the mark in an arched po- sition with two spans distance between the thumbs. This is called the ‘‘crouch start” and is used by all good runners. At the starter’s command ‘“‘Set,”’ or ‘‘Get set,” raise the right knee 6 in., or so that the lower leg is horizontal. Incline the weight forward on the hands and left leg, arms bent a little. Note that the shoulders are forward of the mark. Do not “crane the neck,’”’ but hold the head natural, eyes on the track about 20 ft. ahead. Contract all the muscles for the spring and hold a steady position. Do not “break’’ (start before the pistol is fired). This is a bad habit of novices, and is cos’ y, since the starter will place you back for each offense. At the report of the pistol spring forward, not upward, from both feet and hands, taking a short, quick jab step with the right foot a few inches ahead of the mark and a little to right. At the same time jerk the left arm forward and the right backward and up. The weight must be well forward and low, the upright position being grad- ually assumed at about the sixth or seventh stride. During the run incline the head forward, the body forward and arched. Hold the arms half bent and use them directly for- ward and backward, the action being all in the shoulder and none in the elbow.. Move the legs directly forward and do not allow the foot and knee to turn outward. Take long, fast strides and run on the balls of Three ways of placing the hands on the starting line preparatory for a dash run the feet (heels up). When the foot strikes the ground in front, the leg should be bent as little as possible; do not elevate the foot high in the rear. Never look around to see where the others are, but fix your eyes on the finish and your whole attention on your utmost effort. When about 20 yd. from the finish get a feeling of fright as though 621 622 running from death. It will help you make a strong finish. It is not possible for all runners to run at top speed in the quarter mile. Those who have little endurance should try to, but those who have great endurance may start a little slower and make a fast finish. Never jump at the ‘“‘tape’’ (finish yarn), but just before reaching it throw the arms forward up and half bent, chest forward and turned a little to one side. Do not slow up until several yards past the mark and then. do it gradually. ON YOUR MARK GET SET PISTOL REPORT Popular Science Monthly a daily rub, kneading, and muscle stretch- ing. Keep the muscles warm and if the weather is cool, wear a heavy robe and take slow preliminary warming-up work. Distance Running Distance runs are those of a half mile or © more. Runs around the half mile mark are sometimes called ‘‘middle distance’ and those of a mile and more “‘long distance;’’ STRIDING The different stages from starting on the line, leaving at the sound of the pistol report, running, and the finish in making a sprint or dash up to and including a quarter mile Just before getting on the mark spend two minutes in deep breathing. At the command ‘‘Set’’ take a rather deep breath and hold it. At the pistol report suddenly eject the air and at the second stride take a quick deep breath through the mouth and hold it. In runs up to 50 yd. do not take another breath. In other distances do not use up all the air in the lungs be- fore inhaling again. In the 100 yd. dash take a short breath at 50 yd. and another at 75 yd. Spend plenty of time practicing the start and learn to hold the ‘‘Set’’ position on the mark. Become familiar with starting from the pistol report. After two or three weeks’ preliminary exercise follow a daily schedule something like the follow- ing, if you are trying to get in condition for a 100-yd. dash. Monday—Four or five starts. Jog 220 yd. with attentior to stride and reach of the legs. Run 50 yd. at top speed. Tuesday—Starts as above. Jog 440 yd. Run 100 yd. at about three-quarter speed. Wednesday—Starts. Top speed 50 yd. Rest. Jog 220. 75 yd. at top speed. Thursday—Starts. Jog 440 yd. Fast 150 yd. but not at top speed. Friday—Starts. Jog 100 yd. 50 yd. top speed. Rest. 100 yd. top speed. Saturday—Jog 220 yd. Rest. Three starts. Fast 75 yd. Rest. Rest 2 or 3 days before a meet but take but they are here considered together — because they require about the same — qualities. Lithe and long-legged runners — are best adapted to distance running. The © erect start is used instead of the crouch. — This is done by toeing the scratch with one — foot, the other being back one pace. There — is no advantage in getting a quick start. — Since the run is slow the chest and head are © held erect, the arms swing rather wide — forward and backward and a little bent. — Some trainers have their distance runners — swing their arms in continuous forward — small circles that look like a “side wheel” — action. All of the muscles should be held — as relaxed as possible. Except in runs of © five miles and more, run with the heels — off the ground. In the longer distances it — is necessary to vary this occasionally to ~ relieve the leg muscles. 4 Special attention should be given to © “striding.”’ A long, regular stride is important. The front knee should be © straight as the foot strikes the ground and that of the rear leg bent only moderately. — The leg should not be swung forward stiffly, — but should be allowed loose free joint play. — Of course it is possible to overstride, and — each runner must learn for himself the longest stride that he can maintain with the greatest ease. An equally important matter is ‘‘pacing” — (maintaining the same speed throughout — or for long stretches). Set the time in which you wish to run the distance and _ do your pacing with a watch so as to time each quarter, but be sure to have enough endurance left to finish with a dash of 100 yd. or more. Do not worry if an in- _ experienced runner passes you in the first _ part of the race and do not allow him to _ pull you into a faster pace. Almost always such runners drop out or fall far behind before the finish. Do not “‘set the pace” (take the lead) all the time unless your regular pace brings you far ahead of the others. If during the last part of a race a better runner passes you try to follow close behind if you are feeling well. It requires years of regular practice to become a good distance runner and no one should attempt to run even a middle dis- tance race without at least a month of care- ful training. Longer distances require more time. Coaches in small schools and clubs often beg members to go into a race ‘‘to fill out,” even when they have had no training, but this should never be done in ‘distance runs. Before starting to train for _ long runs get a medical examination and _ occasionally thereafter. No growing boy -should train for long races. Jogging gradually up to a mile or two is good practice, but not for boys below fifteen or sixteen. Regular and good habits are necessary, as well as a good digestion, plenty of common food, and a careful watching of the weight. ___ Proper foot-wear is important. A soft, light, laced shoe with firm _ but flexible sole and low heel, snug-fitting, but not at MY } alcohol and if they. be- ) come sore rest un- ) til they are well. Bathing in alum ) water is good for excessive perspi- ration. On cinder tracks spiked /shoes may be worn, but never on hard tracks, roads, or cross-country. Breathe through the nose as long as it | is comfortable, but do not hesitate to | breathe through the mouth if the nose } breathing is not free and comfortable. In | either case both inhalations and exhala- | tions should be well controlled. STANDING START GOOD FORM Popular Science M onthly 623 Training Tables When first starting to train for a half mile run, jog a half mile every day for two weeks. Every other day run another half after a fifteen minutes’ rest, then adopt a weekly schedule something like the following: Monday—Jog three-quarters of a mile. Tuesday—Run 600 yd. in fair time. Then do two 50-yd. sprints. Wednesday—Run a mile at an easy gait. Thursday—Run a half mile at a comfortable gait. Friday—Practice sprinting altogether (half Rest. doz.) Saturday—A half mile at a good gait. Schedule for the Mile Run Preliminary work for the half mile. Monday—Three or four short dashes. Runa mile with a good pace for the first 100 yd. Tuesday—Half a mile at good gait. Rest, then jog a half mile, sprinting the last 0 yd. Watnesdey and which is entirely suitable for ‘use in either the primary or secondary circuit of any normal radio receiving pparatus. It is the purpose of the present e to show how one or more of these variable condensers may be used to the greatest advantage, both for increasing sharpness of tuning (and thereby lessening interference difficulties) and for increasing ‘signal strength. The great advantage which is secured immediately upon the use of a variable condenser is in the flexibility circuit adjustment which can thus be Practically all the effects of mere tuning to wavelength can be obtained from riable inductances alone, using fixed con- ers. However, to change the ratio of 2 Mactance to capacity, which is one of the mportant factors governing sharpness of tuning, it is necessary that both the con- and the coils be variable; if only e element can be altered, it is not possible 0 secure any desired ratio at any desired velength. A second advantage gained by using variable condensers is the mechanical _ simplification of the inductance coils con- _ nected with them. Since the condensers are sontinuously adjustable, and can therefore _ beset at any desired value of capacity with- _ out the limitation of switchpoint steps, it S$ unnecessary to take out many coil taps _ in order to get close variation of inductance. Any wavelength can be tuned to with ac- , with only a few steps or connections 1 each inductance coil, because the con- r fills in the tuning range. 4 _ Advantages of the Sharply Tuned 4 Secondary 5€ : et dens Sers bs le { I» ES Ha i; There has been some dispute as to i a secondary tuning condenser, ected in the usual way, shown in Fig. 1 and 2, aids in producing a receiver more ive than the simple “broad tuned secondary” circuit. Extended trials have | om beyond a doubt that the sharply tuned circuit of Fig. 1 and 2, when properly i i | | } { How to Become a Wireless Operator VIII.— Tuning with the Variable Con- denser in Primary and Secondary By T. M. Lewis adjusted, will give greater selectivity for the same strength signals than the circuit without variable condenser in the secon- dary. By building the secondaries specially to suit each case, about the same maximum signal strength may be had with both types. With the secondary variable con- denser, however, the maximum signals are secured with looser coupling between primary and secondary. As a result, the tuning is sharper and interference is much reduced. The practical actions of such tuners as Fig. 1 and 2 represent should be studied in detail by every operator, and the TRANSFORMER FC _ } TELEPHONES Oe The receiver is set up by combining the tuning coils with the variable condenser differences in operation dependent upon closing and opening the condenser “switch” in the secondary circuit should be particu- larly noted. The receiver of Fig. I is set up by com- bining the tuning coils described in the February article with the variable con- denser of last month. The resulting arrangement is capable of excellent signal intensity and tuning sharpness. Although it is a directly or conductively connected auto-transformer type of receiver, it has variable coupling. between primary and secondary, and is therefore not open to much of the criticism applicable to the ordinary ‘‘two-slide tuner’’ combinations. For the same reason it requires more careful handling in order to produce the best results. In operating any of the tuners described, it must be borne in mind that the instruc- a 629 630 tions of this article apply solely to the proper manipulation of the inductances and condensers. Before beginning to tune, the operator must have made sure that his connections are properly fastened, that his aerial and ground leads are correctly arranged, that the telephones are in good FIG. 2 The usual inductively coupled type of a receiv- er employed in the majority of wireless sets condition and that the detector is adjusted to a sensitive point. The two last-named items are all-important. Each time the receiver is operated they should be tried out by a ‘‘test buzzer’? equipment such as described in the December, 1916, article of this series. Once these preliminary’ steps are gone through, the entire attention may be devoted to tuning. Unless you are certain that the rest of the apparatus is in working order, however, much time and effort will be wasted in trying to build up signals by tuning alone. Tuning the Coupled Receiver The tuner of Fig. 1 has five tuning adjustments. The positions of switches A, B and C govern the wavelength to which the primary or antenna-to- ground circuit is tuned. The third adjustment (switch C) also determines the coupling between pri- mary and secondary. The fourth switch D, and the secondary variable condenser, fix the wavelength to which the secondary is tuned. The more turns of loading coil included in circuit by the switches A and B, and the more turns of transformer coil cut in by switch C, the greater the tuned wave- length of the primary circuit. Also, the more turns cut in by switch C, the closer the coupling between primary and secon- dary and, consequently, the broader the tuning of the set. The more turns of the transformer coil cut into the secondary circuit by the switch D, and the greater the active capacity of the secondary vari- Popular Science Monthly able condenser, the longer the tuned wave- length of the secondary circuit. Having noted the effects of the various | switches and the condenser, as above, and — bearing in mind that the object of tuning — is to get the primary tuned wavelength and — the secondary tuned wavelength to be as nearly as possible equal to the wavelength — being received, it is not hard to see how the various elements must be adjusted. There — is an additional object, however, which complicates matters a little; that is, the — coupling between primary and secondary — must be made as loose as possible without — sacrificing strength of signals. Since reduc- ing the number of turns cut in by switch C_ loosens the coupling, it is clear that this switch must be kept as near to zero as possible without weakening the signals too greatly. | First Operations in Tuning It is almost impossible to adjust the five variables to their best points simultaneous- ly, so the best plan is to eliminate certain of — them from the preliminary operations. In beginning to tune in a signal, therefore, open the switch which thus disconnects the secondary condenser. This gives the secon- dary a broadly tuned character, and makes — it much easier to “‘pick up’’ a strange, incoming message. Next, cut in nearly all of the secondary inductance by setting switch D to a high value of turns. Since the secondary con- denser is cut out, this SEC. ae COIL PRIM. LOADING COIL FIG.3 Loading coils added to the primary and secondary circuits for tuning long waves has the effect of bringing the seconda’ y circuit more nearly in tune with the usual wavelengths than would be the case if fewer turns were used. Third, set the coupling switch at forty or fifty turns (unless the wavelength you expect to receive is very short, when fewer coupling turns will be so as to make the coupling quite ( 2 and therefore to aid in hearing signals tC Siechich the apparatus is not accurately tuned. Fourth, set the single-turn switch & at the middle of its arc, and finally try to pick up your desired signals by moving : ten-turn step primary switch A. As usec _ with a receiving transformer of medium size soon as signals are heard, reduce the num- ber of coupling turns by switch C, at the same time compensating for those cut out of the primary circuit by correspondingly ¥ ing the turns of the loading coil. hen the best settings of switches A, B ind C are found (that is, the points upon | _ the signals are loudest), close the “secondary condenser switch and set the Bendary contact D to the button giving the loudest signal. Then adjust the con- dens er itself until the signals are loudest; ‘and the receiver will be about at its best j ; justment. _ Further improvement in signal intensity tan be secured by readjusting the primary e-turn switch, B, after the secondary Eiacly tuned. Sometimes it is best to thange the position of the coupling-switch eter the secondary condenser is cut in. this must be determined by trial for : particular station heard. The impor- se things to remember are, to make the : primary adjustments first, the secon- adjustments second, the final coupling justments third, and to try both the | pr single-turn switch Band the opi condenser last, in order to make er improvement in signal strength or tuning sharpness, every time any other eement | is changed. _ The Inductively Coupled Receiver The circuit of Fig. 2 is the usual induc- 1 wey poupled type used in most receiving iiecrea Popular Science Monthly Y 631 sets. It is entirely satisfactory for general receiving, but must be handled carefully in order to give the best results. Its manipu- lation corresponds very closely with that just set forth in detail for the auto-trans- former tuner. The only radical difference is that coupling is changed by moving the primary coil physically with respect to the secondary. As before, the more turns of primary cut in between the single-turn switch B and the ten-turn switch A, the greater the tuned primary wavelength. Similarly, the more turns of secondary coil cut in by switch D, and the greater the active capacity of the variable condenser, the greater the secondary wavelength. Again, the farther apart the primary and secondary coils, the weaker (looser) the coupling between them and, consequently, the sharper the tuning and the less inter- ference difficulties. The objects of tuning are, as before, to adjust the primary and secondary tuned wavelengths to agree with that being received, while at the same time keeping the coupling as loose as possible without destroying the signals. The plan to follow, therefore, is to open the secondary condens- er switch and cut in a large portion of the secondary coil as before. Then close the coupling by sliding the coils well together. Finally, search for the desired signals by making rough adjustments of the primary. When signals are heard, open the coupling by sliding the Man uo coils farther apart and at the : same time adjust both the SEC. se SE COIL a \ a FiG.5 A variable condenser inserted in series with the aerial connection for short wavelengths primary switches to the point where signals are loudest. Then reduce the number of secondary turns and cut in the secondary condenser, setting these to the points which give best signals. For the last adjustment, open the coupling still further and tune the primary and secondary still more accurately. Always bear in mind that the three groups 632 of settings (primary, coupling and secon- dary) are physically interlinked and that whenever you change any of them you must try the single-turn primary switch and the secondary condenser in order to find out whether you are hearing the loudest possible signals. In picking up very weak signals it is sometimes necessary to adjust the large primary and secondary steps together, since in that way the circuits are kept more nearly in tune all the time, and weaker signals can be heard. Under such condi- tions, it is evident that when few primary turns are in circuit the secondary switch must be near its zero point, and that as the number of primary turns is increased the number of secondary turns must be in- creased correspondingly. Such detailed handling of the apparatus can only be PRIM. SEC. COIL / COIL sec - DET. VAR COND. a. \ "h A circuit with switches to connect variable condenser in series or shunt with primary FIG. 6 learned by experience, however, and for cases of this kind these instructions can do little more than suggest a line of action. Receiving Long Waves For tuning to very long waves it is some- times necessary to add loading coils to primary and secondary circuits, as shown in Fig. 3. The addition of active turns to the primary of course increases its wave- length range; a similar effect is had in the secondary. The wavelength of the secon- dary circuit may be increased by enlarging the size of the secondary variable condenser, and when this is done the secondary loading coil is of course unnecessary. Neverthe- less, it is a good plan to keep the inductance of the secondary large, and its condenser correspondingly small; the additional load- ing coil is therefore the preferred method of extending the tuning range to include the very longest waves. When the main transformer is very small and the received waves are exceeding long, it may not be Popular Science Monthly condenser than when the same long wave is possible to get close enough coupling unless the primary and secondary loading coils are placed near together so that they act as an additional transformer. When this is done, care must be taken that the direction of connection is correct; otherwise the induc- tive effect between the loading coils may neutralize instead of helping that between the original primary and secondary coils. _ Another way of getting long wavelengths with a comparatively small receiving trans- former is shown in Fig. 4. Here a second variable condenser is shunted across the primary coil terminals, which has somewhat the effect of increasing the capacity of the antenna. This arrangement has a number of advantages, among which is that by its use the fine tuning of the primary can be accomplished by varying the condenser, and that, as a result, it is unnecessary to build the primary coil with a single-turn switch. Further, and especially when very small receiving antennas are used, signals may be louder with this shunt prima received by adding the primary loading coil. In Fig. 4 the secondary loading coil is shown, but, as before, its effect of increasing the tuned wavelength may be obtained by enlarging the secondary condenser. Tuning to Short Waves When it is desired to receive wavelengths which are short compared with the funda- mental wavelength of the antenna, it is very convenient to insert a variable condenser in series with the aerial connection, as shown the size of the receiving antenna, and makes tuning to short waves a very simple matter. As when the primary variable condenser was used in shunt (Fig. 4), small primary inductance steps are not needed, for the sharp tuning may be secured by means of the series condenser. With the arrange- ment of Fig. 5 it is also possible to tune to wavelengths of the medium range, since the inductance in series may be increased te give the period desired. When used in this way the signals are sometimes weaker than those obtained from the arrangement of Fig. 2, but the tuning is usually sharper, because the ratio of inductance to capacity is increased. ; The primary circuit is shown in Fig. 6, which may be arranged with two single- pole double-throw knife switches so as to connect the variable condenser in series or in shunt with the primary, or to cut it out altogether. With both switchblades at the left, in positions W and Y, the condenser is in series, as shown in Fig. 5. When both switchblades are thrown to the right, in positions X and Z, the condenser is in shunt - to the primary coil, as in Fig. 4. When _ the upper switchblade i is at the right and the lower at the left, i.e., in positions X and Y, the variable ‘condenser is cut out and the circuits are connected as shown in _ Fig. 2. This same switching arrangement _ may also be used with the autotransformer _ arrangement of Fig.1. Practically the same results will be secured, except that the pri- mary turns are changed whenever the switch C (Fig. 1) is moved to vary the coupling. _ Experienced radio operators, as well as beginners, will find it worth while to study the principles explained in this article. _ They are the basis of successful operation _ of the coupled receiving sets. (The end) _ Power Measurement Method Without a Watt-Meter ANY amateur electricians would like to know the power consumption of Bedevices they construct, but do not have access to a watt-meter. The watts con- _ sumed may be found as follows: Turn off _ all lights in the house except one of known 3 power consumption, and count the number - of seconds required for the watt-hour 4 meter’s disk to make one revolution. Then turn out all lights, connect into the circuit : the device whose power consumption you desire to know, and again count the number _ of seconds for the meter disk to make one revolution. To find the power consumed by the device, multiply the watts of the lamp by the number of seconds required for a revolu- tion of the meter disk when connected and _ divide by the number of seconds required for a disk revolution with the device itself connected. For example, one meter re- quired 30 seconds for one disk revolution with a 25-watt lamp connected, and 60 seconds with a small transformer furnishing The power consumption of the transformer and motor was thus 25 X 30 + 60 = 12.5 watts. If the disk runs so fast that it is diffi- cult to time it for one revolution, the time for a greater number of revolutions should be taken, the number being the same with the device tested as with the lamp. Popular Science M onthly current to a small motor connected with it. . 633 An Easily Constructed Detector-Stand for Wireless Instruments DETECTOR-STAND can be easily made from a few simple materials. Procure a piece of brass 1/16 in. thick, and cut it into the shape shown at A. The openings may be made by drilling holes and a> Crystals L9 A detector-stand which can be easily made by the amateur from a few simple materials filing the edges. Bend the brass on the dotted lines so that a U-shaped piece is formed with the slots parallel. Obtain a brass or copper ball 1% in. in diameter, and drill a hole through it to admit a brass rod 134 in. long. Thread one end of the rod to fit the insulating knob. Solder the ball and a piece of fine brass wire on to the rod, as shown at C. The point of a gold scarf-pin may be soldered on to the end of the wire to serve as a “‘cat- whisker.” It is easily adjusted. The standard B is heavy brass, bent on the dotted lines. The cup, with the crystal, is fastened to it with a screw asshown. The inverted position of the crystal prevents dust from settling on it and maintains its sensitiveness. The base may be made of al aT $s a Sere I B41 | sorcerea + f+ of —L ' eC 4 Neh oe 9 Go/d port Construction diagram of the home-made detector-stand showing dimensions hard rubber or any hard wood. Be sure that the uprights of the piece A are just tight enough to hold the ball in place. The knob can be moved backward or forward, or in any direction desired to secure the best crystal setting.—G. F. Exner. 634 An Inexpensive Tester for an Electric Lamp HE drawings show how to rig up an inexpensive tester for lamps for use on I10, 220 or 440-volt lines. First cut a board as shown in the first sketch, making it about 8 in. in diameter, with a handle long enough for a good grip. Lamp sockets on a board cut likea paddle for testing lamps of different voltage Then locate four lamp-sockets as shown. If the upper end of the sockets are tapped for a 3% in. pipe, cut nipples long enough to reach through the board. These hold the sockets in place. Binding-posts are located at A, B and C. A hole is bored through the handle of the tester, large enough for the lamp cord and connections, as shown. The tester may be changed to receive current from any of the three different voltages, by simply attaching the loose end to the different binding-posts, ac- cording to the voltage of the current. In brief: Attaching the end to A makes a circuit for 440 volts, to B, for 220 volts, and to C, for 110 volts. New globes are used in the tester, and the lamp to be tested is placed in the last socket on its circuit. An Emergency Electric Plug Made of Broken Lamp HEN the extension plug to the Christmas tree lighting outfit was left loose on the floor, and was kicked into the open grate fire, an emergency plug had to be made in order to hold Popular Science Monthly the celebration according to schedule. An old fuse plug was used for this purpose. One wire was soldered to the shell and the other to the brass stud in the center. A disk of fiber with holes for the wires was substituted for the mica. This made a good and serviceable plug, which has been used several times for other purposes.—AARON E,. SMITH. A Mechanical Rectifier as a Wireless Receiver ie is well known that the power of the high frequency current set up in a receiving antenna, by the arrival of normally strong waves, is much more than enough to operate a_ telephone receiver. There is no need of amplifying the effects of this received energy; it is merely necessary to convert it into a form which is suitable for the operation of a telephone or other ordinary indica- tor. Since the radio frequency current itself is too high to cause energetic re- sponse of the regular magnetic tele- phone, the conversion need be merely a | reduction in frequency; as an alterna- tive, the energy may be rectified into pulsating direct current. The crystal rectifiers which are used in so many stations serve to distort the current of the received waves so that, as it reaches the telephone, it is stronger in one direction than in the other. Thus for each group of waves the diaphragm is attracted or repelled (according to the polarity of the current pulse) a single time. If sustained waves are received it is necessary to break them Eyed By changing the speed of the interrupter a musical signal of any pitch can be secured 2 up into groups, in addition to rectifying them as just described, if tonal signals are desired. The groups may, for example, be secured through methods involving interrupters, or “beats” pro- duction. Popular Science Monthly There is no need of any rectifying crystal or other complex conducting system if the incoming oscillations are passed through a high-speed commuta- tor. The tone-wheel, formerly used at the Tuckerton Transatlantic Station, is an apparatus whose operation has been described as mechanical rectifica- tion. A nearly identical device is shown in U. S. Patent 1,172,017, which was applied for by R. A. Fessenden in 1906 and was issued during the past year. The drawing indicates an antenna I connected to earth 2 through a primary inductance 17, which serves both to tune the aerial system and to couple that circuit with the secondary coil 18. The upper terminal of 18 leads to a rotating contact arm 5 which passes at high speed over segments 7, 8 of a large commutator. The lower secondary con- nection is taken through a telephone 20 and the wire 37 to the group of alternate segments marked 8 and connected to- gether through 8a. If the brush 5 is rotated at a high rate it is possible to secure synchronism . between the time of contact and the alternations of the received-wave cur- rents. By arranging matters so that the rotating contactor rests upon a segment of the No. 7 group during each negative half-wave of received current and upon a No. 8 segment throughout each positive half-wave, a positive direct current will flow through the telephone whenever waves are received. Thus the system acts mechanically to convert the radio-frequency alternating current into direct current suitable for producing telephonic effects if interrupted. As shown in the diagram, only one-half of the wave-current is used; by connecting another ear-piece, such as 20, to the remaining group of segments (No. 7) and carrying the circuit to the lower end of 18, both halves will be made effective. When receiving sustained waves it is merely necessary to run the commutating contact at a speed slightly different from synchronism, if a musical note is desired. The interruptions then gradu- ally change in relation to the half-waves, so that for a time the rectification is positive and then for a time negative. The rapidity of change of rectification ety depends upon the difference : tween the interruption frequency and _ that of the waves. 635 Making an Inclosed Rotary Spark Gap EVERAL enclosed gaps such as are herein described have been made by the writer and have not only proved very efficient but also have reduced the noise of the spark a great deal. The dimensions given in this article ~ The rotor is made from an aluminum zinc combination casting to prevent wearing are of course applicable only to one size motor and may have to be changed. If the amateur has no motor, one of about 1/10 horsepower, which is either induc- tion or series wound, should be procured, as this power will allow for a larger and more accurate rotor. If an induction motor is used, the number of points or lugs on the rotor should be such that it will give a frequency of any odd multiple of 120, such as 360, 600, 840 or 1080 sparks persecond. This will give a clear note or 60 cycles without any undertone. The rotor (Fig. 1), is made from an aluminum zinc combination casting, as A Cc B Bi tec Po he are! sa iL @') =a or. | it ‘ Pt SET O© © Hl FIG. 2 Dimensions of the parts required for at- taching the handles to the spark-gap frame this will not wear away very fast and is easy to work. Pure copper can also be used if one has a motor of % horse- 636 power or more. The pattern for the cast- ing should be about 7% in. in diameter by % in. thick and have an inside diam- eter of 4 in. The casting should be faced off in a large chuck as shown at A, B and C, Fig. 1, and have two circles marked on it of 434 in. and 6-in. diameter. If the constructor has not a large chuck the Dimensions of the hub for the rotor which may be made of brass or machine steel casting may be turned up by screwing it to a flat piece of wood. To do this one must drill about four holes in the casting, countersinking them 1/16 in. below the surface near the outer edges, and fastening to the wooden plate with wood screws. After the casting has been turned to size it should be removed from the lathe and distances stepped off around the 6 in. circle according to the number of lugs desired. The plate or casting should then be drilled so that lugs 4 in. wide in circumference are formed as shown at D. When only a few lugs are required for the gap, as when used ona high speed motor, it may be necessary to drill several holes together as at FE. There should also be six holes drilled with a No. 28-in. drill at points equi- distant on the 434-in. circle. These are to be tapped out for an 8-32 thread. When this is done the casting should be cut with a hacksaw through the re- mainder of the 6-in. circle, thus giving the rotor shape roughly. It will be found that if before drilling with the 1-in. drill a small drill about 1/16 in. in diameter is run through, the 1-in. drill will not slip out of place. For highest radiation it will be found that some frequency between 300 and 800 works best, although the higher Popular Science Monthly notes are more easily read through static. There should be two pieces made of each part shown in Fig. 2 and (except for the handles C) they should be made of copper. Brass will do, however, except for the sparking surface B. The part A is made of 4-in. round rod about 234 in. long threaded on one end. for about 34 in. with a 14-20 die and having a shoulder about 3/16 in. in diameter and 4 in. long on the other end. The parts shown at B are the electrode tips which are made of copper 4% by &% by %& in. drilled 9/32 in. deep on the side with a 3/16-in. drill. These last pieces may be soldered on the pieces A or may be driven on and secured with a small brass pin. The handles shown at C are about 2 in. long and may be made of black fiber, or wood painted black. Small switch handles, such as are used on 30 amp. I10-volt switches, may be used. The handles should have a 7/32-in. hole drilled in them 1 in. deep.. The parts shown at D are made from \ by 1%-in. copper, 24% in. long drilled as shown, two holes with a No. 10 drill about 34 in. from the edges and a ¥y%-in. hole in the center to fit parts shown at G. These pieces are made of 34-in. round rod and are drilled through with a \-in. drill. There is a No. 21 drill hole for a 10-32 set screw at the larger end. These pieces should be oe S aia f FIG. 4 A hardwood block of oak or maple is turned to the dimensions for the frame be 4 ae | a ele |} oo° | -~-- ----5----4 soldered into the center of the parts D. Instead of the pieces shown at K, 10-24 hex nuts may be used of a large size so as to look well with the thumb nuts shown at L. In Fig. 3, A-B is the hub for the rotor, which may be made of brass or machine steel, 134 in. in diameter. The _ Popular Science M onthly four small holes should. be drilled with a No. 21 drill and threaded 10/32 and the center hole should be the size of the motor shaft. The insulating bushing between the hub and the rotor casting is D ] oa > : 2 el o 4 = & I ry + aye The cover for the casing is of black sheet fiber and is screwed on like a cylinder head made of black fiber 514 in. in diameter and turned as shown. It will be found worth while to corrugate the sides with a round nose tool as shown at D, as this reduces surface leakage and im- proves the appearance of the rotor. The fiber’ piece should have No. 18 drill holes in it to correspond with those on the 434 in. circle of the casting C. There should also be No. to drill holes at the center corresponding to those in the hub. The rotor may then be as- sembled with round head screws and balanced. This may be done by putting a small piece of rod the size of the shaft in the hub and fastening it securely with the set screw. It should then be rested on parallel knife edges and drilled out at © various points on the back toward the inner edge of the casting until it will rest at any position. The knife edges must be set absolutely level. The wooden block shown in Fig. 4 is of quartered oak or maple and is 24 by 8 by 8in. This block should be planed absolutely square. If it is turned off center as shown, the casing will be more accurate than if the block were turned and then the three sides cut off. The block should be hollowed out 6% in. in . __ diameter and 134 in. deep and drilled as ___ shown in the illustrations. 637 The holes in the bottom of the block are for mounting it on the base, Fig. 5. C, and a center hole about 3/16 in. in - diameter should be drilled for a 3/16-in. flat head bolt, and 1/16 in.on each side of it to receive a wood screw from the base. The three holes in each side’ should correspond to those in electrode plates. (Fig. 2; D. E.) The fiber cover for the casing is shown at A-B, Fig. 5 and is made from 5/16-in. black fiber sheet. Thesmall hole around the periphery should be 5/16 in. in from the edge and drilled with a No. 18 drill to allow the use of about 34-in. round head brass wood screws to fasten cover to wooden casing. The large holes shown are for small circular windows to observe the spark and for adjustments. For glasses, the lenses of the cheap grade of automobile goggles may be used by cutting all the metal away except a small rim around the glass. If you have not a drill of the proper size one can be improvised, as shown at D, by taking a piece of 34-in. machine steel with a rectangular hole cut through it and a piece of hardened tool steel about 4 by \ in. driven in and ground to a cutting edge. When using a drill of this sort, a hole the size of the machine steel—*4 in.—will have to be drilled through the cover. Drill about 1/16 in. ES SEEN batev is a Three views of the gap, as it is attached to the motor and the front and back sides deep on each side of each hole the exact size of the glasses and then grind off the drill about 1/16 in. on the radius and con- tinue the hole through. The glasses 638 may be glued in place and should be double, one inside and one outside of each hole. The base shown at C, Fig. 5, is made of %-in. or 1-in. quartered oak stained and waxed, and drilled as shown to correspond to the motor base and gap casing.” For assembling there will be needed four round head brass screws to fit the thumb nuts of Fig. 2, 2 flat head wood screws about 1% in. long, one 3/16- in. iron machine screw about 134 in. long having flat head and a nut and washer, and a dozen % in. or 34 in. round head brass wood screws. In Fig. 6 are seen three views of the complete gap. The wood block should be mounted on the base by means of the 114-in. wood screws and the 3/16-in. bolt, the flat head being on the inside of the block. Then the motor should be mounted in place on the base, with its shaft extending into the casing. The electrode bushings should be put in place on the sides as shown, using the 4 screws whose heads may need to-be filed flat to about 1/32 in. thickness, and the thumb nuts and hexagon, or round nuts, as binding posts. The electrodes may then be placed in the bushings and the wooden handles put on. Last of all, the rotor should be firmly fastened on the motor shaft with its set screw and the fiber front should be screwed on with the /%-in. round head brass screws. (B, Fig. 6.) Then the gap is complete. To insure the desk or table top against any slight vibration arising from the motor, blocks 1 in. square of sponge rubber should be placed under each corner of the base. Before starting the gap be sure to have the electrodes fastened in the proper places with the set screws in the bushings. The gap described here is sufficiently large for a 1-kilowatt outfit using 10,000 to 20,000 volts. If the constructor has access to a _ milling machine the Casting can be much smaller; but the method shown in Fig. 1 will give satisfaction. A Simple Method of Measuring Capacity of an Antenna EFERRING to the diagram of con- nections, it will be seen that E isa buzzer; F, one or two dry cells and Ia crystal detector. J represents the tele- Popular Science Monthly phones; G is a-variable condenser of known values (i. e., calibrated) and H is the condenser which is to be calibrated and whose capacity is unknown. A, B, C, D are four equal inductances as described below. This method comes within the scope of material and instruments which the average experimenter has on hand, and is also very accurate. The detector, buzzer and telephones are of any of the familiar types. The i : A f i ae ; M Gt Diagram of connections for the apparatus to measure capacity of antenna wires inductance coils should be made by winding four separate and similar coils. Each one is to be made as follows, or as nearly so as may be convenient with the wire, tubes, etc., on hand. Upon cardboard tubes 2 in. in diam. and 134 in. wide, wind twenty-five turns of No. 22 single copper-covered wire. Coils B and D are to be connected in the opposite direction to the wind- ing on coils A and C, so that the two circuits will be opposed. After connecting in the condenser G to be measured, turn the handle of variable condenser G until no signals are heard in the telephones.. Then the capacity of H will be equal to the capacity of G, which of course must be ascertained from the calibration curve sheet. The operation should be per- formed very slowly as the ‘‘no signal” point is very sharp and it is very easy to pass over it. In ordinary operation the coils A and C should be kept at least 3 or 4 in. from coils B and D, so that the coupling will not be too close. It will be noticed that on all other points of condenser G a continuous signal will be heard from the buzzer. A calibrated condenser covering a range from .0002 to .0025 or even .003 microfarads is a good size to have. _ constitute a powerful microphone. Popular Science Monthly This method can be used nicely for finding the capacity of an antenna if the ground and aerial leads are placed across inductance C in just the same manner as when connecting a condenser to be measured. If it is found that no zero-signal point can be found by varying G, try reversing the connections of one of the coils (D, for example). If still no zero-point is found, the condenser G is probably of different value (throughout its range) than con- denser H. To get silence in the tele- phones when the condensers are equal, the coupling of A to B should be the same as that of Cto D; otherwise there will be only a reduction of sound at the balancing point. How to Make an Experimental Dictograph HE word dictograph is a trade i name used to designate one make of telephonic instrument for re- ceiving, transmitting and magnifying sounds. In a compact form it may concealed and used in various kinds of detective work, conveying to the waiting _ listener, unknown to the _ suspected person, what is being said. Such an instrument can be easily made by any one having even a small amount of knowledge of electricity. All instruments of this class are a com- bination of a telephone receiver with some form of a microphone, which is used as a transmitter. Such an instru- ment consists of a cell of granular carbon between two carbon electrodes. The back electrode is fixed, while the front electrode is carried on a thin iron diaphragm. The carbon disks and the granular carbon held between them On account of the weight of the iron dia- phragm and the electrode attached to it the inertia of these parts is compar- atively great so that it is not affected by very faint vibrations, and to transmit the voice properly the person using it must be close to the transmitter. To make a microphone useful for the dicto- _ graph it must be so sensitive that it will reproduce the voice when the speaker is a distance away. This may be accom- plished by using a microphone in which _the only moving part is a light carbon diaphragm. An instrument of this type 639 is shown in detail in the illustration. A carbon button containing on one face a number of depressions is held near - acarbon diaphragm. The button forms one electrode and the diaphragm the other. The current flows from the button to the diaphragm through the granular carbon which half fills each depression in the button. The atmos- pheric vibration set up by the voice causes motion of the carbon diaphragm which is transmitted to the granular carbon, increasing or decreasing the pressure of the carbon grains against each other, and causing variations in the current that will reproduce in the receiver the sound of the voice which caused the vibrations. A transmitter of this general type, together with a telephone receiver, a switch, and two battery cells, con- nected as shown, are the essential parts of all instruments of the dictograph type, as well as for all telephonic aids to the deaf, any one of which may be used as a dictograph by employing leads of proper length to allow the instrument to be placed as desired. — The experimenter can find the parts necessary for making the transmitter listed in catalogues of ele¢trical supply houses —carbon backs, carbon dia- phragms and grain carbon. In making the transmitter care must be taken to place the diaphragm so that it does not touch the carbon back and still is close enough to prevent ‘carbon grains from Switcn ae is BLOTTING PAPER WASHERS CARBON DIAPHRAGM, CARBON BUTTON CARBON GRAINS — MICA INSULATION METAL CASE TRANSMITTER IN SECTION—™ Connections for the battery circuit and a cross section of the transmitter getting between the diaphragm and the carbon back. The transmitter must be held in a vertical position, or the grain carbon will not lie against both the diaphragm and the carbon back. A switch is provided for opening the circuit. 640 Electromagnetic Rotation of an Electrolyte HE following interesting experiments may be performed by, anyone possess- ing an electromagnet. The apparatus used is very simple and is shown in Fig. 1. The base A is a cardboard about 2 in. in diameter and B is a \%-in. brass tube placed in the center of the cardboard. A tit bh Fig! tit == — SSS A brass cylinder is fastened with sealing wax on top of a magnet and holds the electrolyte brass cylinder C,1%in. to 2 in. in diameter, “js placed upon the cardboard. The sealing ‘wax D is placed in the bottom to secure ‘the cylinders and protect the cardboard. It should be slightly concave, as shown, for the mercury experiment. The part repre- sented by Lis an electromagnet. In its stead the primary of an induction coil, or a strong permanent magnet may be used, if an electromagnet is not available. The electro- magnet should be connected with a suit- able source of direct current. A connection is soldered to the brass cylinder at a point on its outer circum- ference and a connection soldered to the tube B. These leads are connected with one side of a reversing switch, as shown, the battery being connected with the center. For the first experiment a fairly con- centrated solution of potassium hydroxide (KOH), or sodium hydroxide (NaOH), may be used for the electrolyte. Now, if the field is excited and the revers- ing switch closed, the electrolyte will rotate about the tube in one direction. If either the direction of the current or the polarity of the magnetic field be reversed, but not Popular Science Monthly both, the direction of rotation of the electrolyte will be reversed also. If a drop of phenolpthalein is allowed to. fall into the solution when it is in motion, — it will give it a striated or lined appearance. - If the strength of the magnetic field or the current passing through the electrolyte - be increased, the speed of rotation is also increased, and vice versa. g In Fig. 2, a globule of mercury (Hg) was placed in the solution, and one end of a wire from the outer cylinder was brought — in contact with the mercury, the outer cylinder being positive and _ the ibe charged negatively. The mercury wa flattened out considerably. In Fig. 3, a wire is connected with the tube instead of the cylinder. When placed in the mercury, it will stretch out in a straight line from the tube to the cylinder. The phenomena of the mercury will take place: without the magnetic field. If, however, the field is applied, the center of the mercury will be convexed in the direction of rotation of the liquid. 4 Sulphuric acid (H2SO4) may be used the electrolyte if a carbon cylinder and ro d : are used. If a metal were to be used, the acid would attack it, and the fumes gi en off would drive the experimenter beyond the range of observation. This arrang - ment, however, will work better than he hydroxide solutions. q Fig. 2 Manner of applying the current to the electrolyte for making the experiments The pole that is charged positively at- tracts the negative ions and vice versa. Thus H,SO,4, when ionized, splits up into the positive ion Hz, and the negative pe SO,. These ions would move radially to- ward the opposite pole, if there were no mag- netic field applied. Upon the applicati on of a vertical magnetic field, the ions will be given a circumferential component of mo- tion. The circumferential component of the viscous drag exerted by the moving ions forces the electrolyte to revolve. Photo New York Edison Co. “THE PoPpULAR SCIENCE MONTHLY is well named, and its mission is being thoroughly carried out by it scriptions of current developments of a me that the publication should appeal and lay readers.” s clear and interesting de- rt and science. It seems tc ) strongly to both technical aay 9 Sy gt ee Throwing a Torpedo-Proof Wall of Steel Around a Ship Mr. Flowers plans to protect ships from torpedo attack by means of rapidly rotating disks of steel. A veritable stream of heavy, whirling disks is shot into the water, forming a steel wall. When it strikes a disk, the torpedo will burst. The twenty-five feet of ocean between the whirling disks and the vessel will serve as a cushion, so that the vessel will not be harmed at all 642 _ Popular Science Monthly me 239 Fourth Prat New York City : ee May, 1917 Areal _ Foiling Torpedoes with Whirling Plates 3 “ ardveda of disks; rapidly tated, are dropped into the water to act as an impenetrable steel wall By John B. Flowers, E. E., U. S. Navy +. LTHOUGH 3 A hundreds of ships have been sunk by submarines since the war began, practically nothing _ has been done toward - thwarting thetorpedo. To be sure, huge nets * _ of steel or of rope have _ been adopted for the _ protection of battle- . ships in some navies, but they are of use _ only when the vessel is anchored. When a ship is under way, _ they produce an enor- _ mous retarding effect. At speeds of six ‘knots and more, they _are literally torn off. cs is all steel with a hol- low air-filled interior. This also sinks very, very slowly. Either kind may be used. If, then, it were possible to pour over the side of a vessel a large number of whirling disks or plates, they would remain suff- ciently long in posi- tion to constitute a protecting wall against a_ torpedo. My steel disks are two inches thick and two feet in diameter. They are built up of one thirty-pound plate and two thin cover plates, which when : Investigations |i Z =| welded together leave : which I have con John B. Flowers, the inventor of the the d 1's k hollow. ducted in an experi- whirling plate system for foiling torpedoes Forty disks are placed “mental tank of great in the magazine of dimensions have con- 7 SPINNING AT 1910 each gun of a launch- vinced me that it is feasible to protect ships from torpedo —_Etiinuit> Sey attack by meansof ““ ay rapidly rotating PRESSURE disks of steel. Ifa jose suuty flat disk spins fast _ sinnine at 300 . REVOLUTIONS PER enough, itscentrifu- minute FLAT BARREL ing battery. They are fed one by one towards the _ rect- angular barrel of the gun by a column of compressed air. SECOND ALLOWING When nearing the OUT OF TUBE top, a disk is caught | . : gal force will keep REE Te iB ae by three rotating e rollers which are re- i ah, in se plane. How the disks are revolved and shot out of the ese isks are launching gun. There are forty disks to each gun volved by an elec- | made up of a metal tric motor. A speed and a wood plate screwed together so they of no less than two thousand revolutions sink very, veryslowly. Another kindofdisk per minute is thus given the disk, and the 480 LBS AIR THRUST \ ; se 643 644 Popular Science Monthly : disk is then ejected: from the barrel by highly compressed air or black powder which pushes against the disk with a pressure of nearly fifty thousand pounds. When the idler disk is pulled down by a magnet, the disk is shot out of the gun with the ones beside it nearly - be said to hold their jobs because of their — Drawing Uncle Sam, the Figure that | Makes or Breaks a Cartoonist d HE ambition of every newspaper car- — toonist is to win praise for his figure of — Uncle Sam. Indeed, some cartoonists may inimitable char- — vertically. An electric timing: circuit automatically controls the fir- ing. The mere pressing of a but- ton starts a con- trol-clock turn- ing, and the com- pressed-air valves and the idler-disk release are elec- trically operated in their turn. As soon as one disk is fired, com- acterizations of — this venerable — and virile gentle- : man. : Who would not recognize an Uncle Sam by Robert Carter, of — the Evening Sun, ~ of New York, or — an Uncle Sam by — John T. Me-— Cutcheon, of the Chicago Tribune, — or the same figure © by Oscar Cesare, © now of the New pressed air brings up another in its iw Waiting for His Contribution J. css! York Evening Post? If these” Lies place. The one clock is con- nected with the controlling mechanism of each gun in a battery. A veritable sheet of heavy whirling disks is shot into the water as the guns are fired simultaneously. Torpedoes can be sighted when from one to two thou- sand feet from a ship. The time consumed in the tor- pedo’s travel makes it a simple matter to aim a bat- tery of my guns in its path. The steady stream of disks ten times two feet wide, three cartoonists — drew nothing but | Uncle Sams they — would still have — the wide follow- — ing that they now — have. Although — the three figures are as different as the cartoonists themselves, they — represent in body — contour and fa- cial expression all — that is distinctly — American. 4 The name off ¢ is as easily fired in the path of "How t the torpedo as if it were a At top: John Cassel, the editorial car- John Cassel, of - stream of water from a hose. eee the New York World Bahg: the New York — The rapid whirling of the disks fete Betow: The finished eae World, should be — at high speed prevents them from turning out of the initial, practically vertical, plane. “Therefore they begin to sink in the water in their vertical direction, and the buoyancy of the disks caused by their hollow interior prevents their sinking fast. A great sheet of rotating disks is formed in the water which is as formidable as if it were a steel wall. Striking one of the disks, the torpedo will burst. That will be all. The twenty-five feet of ocean between it and the vessel will serve as a cushion, so the vessel will not be harmed. linked with the three cartoonists mentioned above. His ~ Uncle Sam is a striking characterization, ~ and not, as one editor remarked, ‘‘a hayseed ~ in a gentleman’s clothes.’’ The illustration ~ above shows how Mr. Cassel draws his figure from a plaster cast, in order to obtain an accurate representation. The cast was molded from an original cartoon of Uncle Sam by Mr. Cassel, and by drawing ~ direct from it he can not fail to get the expression and atmosphere that beloamy to his productions alone. aig ad mi y * yey Rr Gy <= Po MACE. eye = Ee WA a, LS Be UE A es ND “a 4 HE photograph at the bottom of the on which are - mounted beveled wheels that rotate the map paper. -of the boards carries the Popular Science Monthly An Automatic Map-Maker. Surveys by Wagon Jolts It page shows a map-making machine. It is the invention of Theodore Bodde, Westfield, N. J., and |} F. E. Austin, Hanover, ‘\)" N. H. A shaft at the |: forward end of the ma- chine is belted to a pulley attached to the hub of the rear wheel. This shaft is geared to a rod Ones’. % drawing paper. A spring- _ supported pencil is arranged to mark on the _ paper as the wagon proceeds. When a map - line has been drawn completely across the paper an alarm bell is automatically rung _to warn the operator to shift the mechanism into position for making another map. So long as the machine or wagon is traveling on a level road both disks are stationary and only a straight map line is marked on the paper as it is moved ‘past the pencil point. But when the wagon turns a corner, a set of gyroscopes geared together are ar- ranged to turn the map board so that the _ map paper is also turned relatively to the ‘pencil point, thus indicating the turn of _ the road by a deviation in the line marked on the paper. Any error in the marking _ that would naturally occur through an : up-grade in the road is automatically corrected on the map by a pendulum at- - tachment which regulates rectilinear mo- _ tion of the map _ paper so that it is always in - proportion to road. The ma- _ chine shown has Scrape the bottoms of your shoes on the little iron bar and then wipe them on the mat before entering the automobile Don’t Soil Your Car Floor—Wipe Your Feet at the Door SIMPLE but effective way of pre- venting muddy shoes from soiling the interior of an automobile has lately been brought out by William A. Roos, of New York city. It consists of a small square mat, with a short iron bar in front, which can be brought down flat on the running- board for use. The mat is made up of a number of short stiff bristles. _ - The bottoms of the shoes are scraped over the front iron bar, which projects over the edge of the running-board as shown, so the mud drops down to the ground. The dirt still remaining on the shoes can be removed by the bristles of the mat. The device folds back into a pocket after it has been used. The last person entering the automobile catches the bottom of the bar with the toe of his shoe and swings it up. Catches on the hinges then hold the device close against the vertical side of the running-board the the horizontal length of the been put to ac- tual use with entire success. The inventor claims that it is more reliable of the car. The back of - the matis enam- eled and finish- ed in such a way that it is not noticeable as a separate de- vice when fold- ed back into its pocket. The floor of the au- tomobile will thus be kept tidy and more comfortable in than the ordi- Nary method. The wagon carries a revolving map paper and a spring- suspended pencil which records the lines of the road damp or sloppy weather. 646 Popular Science Monthly before peeling. .Each piece should — weigh not less than one and one-half — ounce. These pieces are planted i in- shallow window boxes in leaf mold, — coconut fiber or sand. The boxes — are kept in the window of a cool but frost-proof room and the sprouts are — grown in them until they are from ~ one-half to one. inch high, Then ~ they are planted as seed potatoes. — To prevent the cut pieces from — shriveling before they are planted, — the cut surface is dusted over with dry, powdery plaster of Paris, dry — slaked lime, or finely powdered char- — intake funnel and head straps. Breathing Fresh Air in a Manhole through a Protector Mask WESTERN manufacturer has put a gas protector on the market which is designed to enable a man to breathe pure air without pressure while he is working in a manhole repairing gas pipes or wire conduits. It has several distinctly novel features. The pure air is drawn through the intake funnel and tubing fastened over the mouth and nostrils, and the used air is expelled through an exhaling valve. The protector weighs but seven ounces. The mask is constructed of rubber and aluminum. Adjustable head straps hold it firmly in place and make an air-tight fit, as the rim of the rubber mask is inflated through an air valve blown up by the mouth each time a breath is taken. The flexible tubing is twelve feet long and is equipped with an intake funnel at its end. A Money- Making Idea! Grow Potatoes in Window- Boxes N view of the shortage of potatoes and onions in America, and of the difficulty in supplying the demand for table use, the question of seed potatoes is a se- rious one. The following plan has been adopted by some thrifty housewives to in- crease not only their individual supply of potatoes but their pin money accounts as well by providing some for marketing. From each batch of potatoes prepared for cooking, a piece from the “rose’’ end (the end where most of the eyes are) is cut off The protector consists of a mask, flexible tubing, It supplies fresh air without any pressure furnished by machinery The portable farm motor is run on either gasoline or kerosene coal. The rose end of the potatoes © is hardly missed, and the seed potatoes are thus obtained at a scarcely appreciable cost. 4 Portable Saw and Pump Outfitsfor _ Farm Use . F great utility about the farm is the — small motor and stand shown in the © accompanying illustration. It can be carried about in a wheelbarrow and may be ~ used to saw wood, operate a pump, washing — machine, churn or even to charge a storage- — battery. Its usefulness is further enhanced ~ by the fact that it can be run on either © gasoline or kerosene. 4 The motor may be obtained in two sizes of three or five horsepower. In ~ each case it is mounted on a small wooden stand, as shown, to drive the ~ desired machine by a belt. The © ' : engine is of the © 4 type, fitted with a high-tension magneto built in the flywheel. It has a standard type carburetor and an integral fuel tank and muffler. A gallon of gasoline will fur- nish enough power to saw a supply of fire wood that will last for a week, and in an ~ hour sufficient corn can be ground to feed 3 a well-stocked farmyard. New York City’s Indoor Golf Course 5 It is played with stove-pipes, bricks, barrels and rugs in the rooms of a downtown club Fg RENTON ils EES? es Le ee a eee OS RL a g ‘= Indoor golf is played without the aid of caddies. No balls are lost, and no golf suits are worn. Nine holes of the course are laid out in the assembly room of the club and nine in the gymnasium Hf ITH steam heat and elevators, in- : direct lighting to take the place of sunshine, and art works on the walls _ to compensate for the lack of landscape, a _ luxurious club or hotel. _ strated during the winter when the rooms of New York enjoys its game of golf in a This was demon- the Telephone Club were the scene of a spirited contest, with ninety-one entrants, playing for a silver loving cup and other valuable prizes over an eighteen-hole course. The players start in the Assembly Room with a shot over the polished floor to the _ edge of the rug. It is not so easy as it seems; for the ball must be in position for a shot through a stove pipe elbow to the hole. Hole 2 is on the edge of the rug, with a neat little barricade of bricks about it in a semi- circle, with a small opening. To make the approach to the third hole difficult, bricks are placed under the rug about the hole to make a lumpy surface that sends the ball rolling erratically. The fourth hole is placed on an incline so that the ball glides back unless it is skilfully played. A carom against a pillar is involved in making hole number 5. Hole 6 is entered through a length of straight stove pipe. Now you tackle a wooden incline with 64 a four inch hole in order to reach No. 7. Hole 8 is a typical side-hill putt proposi- tion, with a cup set at an upward angle. For hole 9 a shot is made through an open doorway to an antechamber, where a woven-grass rug provides a fast green. This concludes the course in the Assembly Room. ‘Now come the nine holes in the gymnasium, where hole number I0 is next attempted through a three-way device, which is likely to send the ball far afield if not carefully handled. After a carom to hole 11, the twelfth hole is played up a carpet runner from the floor to the stage. The unlucky number which follows involves a shot down from the stage and up another incline to a level spot. After this, hole 14, which is completely surrounded with bricks and requires the use of a mashie, seems not so difficult. Hole 15 involves simply a straight shot along a runner to a hole on a raised plat- form. | Sixteen a relief to the tired golfer—a straight hole, without obstacles or concealed traps. On hole 17 are three bunkers, the hole being located between second and third. Asa grand finale comes hole 18—a barrel hung from the ceiling. For this a mashie and three trials are allowed. is ~ This Head of Lincoln Seems Almost Flesh and Bone © Underwood and Underwood, N. Y. George Barnard working on his statue of Lincoln’s head. The lady watching him is Miss Ida Tarbell, the magazine writer and author of a life of Lincoln. Of Barnard’s statue Miss Tarbell says: “It is the profoundest thing yet done on the man. Barnard has studied Volk’s wonderful life mask until he knows every wrinkle, every growth, every ridge in the gnarled and furrowed face.” The statue is fifteen feet high. Study it a moment and its trueness will be apparent 648 A herd of angora goats feeding upon a Govern- ment scrub-oak range in Arizona. Goats are notorious for their di- gestive apparatus, eat- ing everything, appar- ently, except rocks. For this reason they Play havoc with a cattle range but clear out scrub-oak thickets A herd of healthy angoras coming down to a watering place for their daily drink at Eagle Pass, Texas. They have been graz- ing in prickly-pear thickets. It takes about four acres to feed a goat, according to a Government investigation record The Swarm of Submarine Chasers Which Is Being Built a ee a eT ee ee ee ae ee ee © Press Illustrating Serv. B Above: A submarine chaser of the latest Below: An entire shipbuilding plant works a type. It draws but thirty inches of water; day and night turning out these chasers for F A torpedo travels at a depth of from eight the British. Each boat is manned by eight r to fifteen feet. The boat’s speed is more than men and the cruising radius is fifteen hundred forty miles an hour. It carries two guns miles on one thousand gallons of gasoline © Int. Film Serv. 650 ‘to Save English Shipping from the Ravages of U-Boats Submarine chasers being built for the British Admiralty at the rate of one a day. These sea- wasps have done yeoman service in the anti-submarine crusade. They are said to have assisted directly in the loss or capture of literally scores of submarines belonging to the enemy The submarine chaser is eighty feet long, with a twelve-foot beam. The cruising radius is seven hundred miles at twenty- two miles per hour and fifteen hundred miles at fourteen miles per hour The motors are of five hundred horsepower and the sea-keeping qualities are such as to allow for a sea patrol of ten days duration. The English 2 channel is regularly pa- ) Photos © Int. Film Serv. trolled by these boats 651 Violets Wasting Their Sweetness on the Desert Air Violets? Acres andacres of them going to seed in the California autumn. There are sweet vio- lets, marsh violets, hairy violets, dog violets and mountain violets all growing in the same field, which is at Coma, California Milady can visit the fields at any time she wishes and pick her own flowers. Violets are prodigious an seed-yielders in the autumn, while the more conspicuous spring flowers with which we are familiar yield little or no seed 652 Rearing Snakes for the Venom They Yield © Newman Traveltalks and Brown & Dawson At top: The death struggle between a poison- ous and a non-poisonous snake. The coils are exerting a crushing force and the fangs of the crushed one are at the other’s throat At top: Dr. Vital Brazil extracting the venom from a poisonous snake. The poison sacs of the snake are pressed, forcing the angry reptile to eject the venom from the fangs Dr. Brazil on his snake farm at Sao Paulo, Brazil. The snakes are raised for the poison which they yield. This is in turn used as an antitoxin for different diseases, including snakebite itself 653 War Pictures of Monastir Under Bombardment by 4 © Amer. Press Assoc. The city of Monastir after its ca aviator snapped the pictures from his war machine. a network of trenches, shown by the black lines, fro were driven out. The black streak across the phot 654 pture by German-Bulgarian forces. A French On the outskirts of the city is m which the defending troops ograp represents the railroad and Bulgarians, Taken by a French Aviator Monastir in the throes of the fierce bombardment. The city was a rich prize for the Central Powers. The white splotches in the picture represent smoke rising from the burning buildings, military stores and granaries set on fire by bursting shells. This is one of the few photographs taken during the war showing a city actually under bombardment 655 Chickens—Chesty and Otherwise a 14 ana Pe beh SOAS) PPI 8 Usaviyy 94} Spnjznye Ysty sy} jo asnessq "z90F PUBSNOY} U993 ITY} JO 9pNz[e ue }e ‘eIAI[Og Ul ‘zegq eT Ye BurAT ‘pysoMm ay} Jo uaxoTy Surpuedxa-}sayo uordureyd ay} ynq ‘uoe3id 193nod & jo NO 33391 $V Sutueay> pue uor}U9}3e JueJsUOD pue BSurIpesj fnyored amber yoryM ‘spmoy as9y} SUISIeI UI JYSI[Op JeNosed oye} osouedel ayy, “[Ie} JOOJ-aajam} & 43M Jojsoo1 ssouedef e—jseq eq ay} Jo sIopuoMm posdyzeaj dy} JO 2uCO yod uvoloury yyNog e& ye uTezded s.oIeED oy} 0} pezvusssid sem uayoryo ayy, ‘sijinb jo pury ppo ue ox] dn payino sed poo 3y3 putysq Ajssajesn suey s8aq jo Jred B1jx9 oY, ‘Ol]leD Joureays ay} Jo jooseur 9y} ‘usxoIyD possa]-Inoy W :2A0qe ajomD uy UOSMBCT DP UMOIE pue syye} “[PABIT, UBTIMEN “90S88Y SSeig ‘i9Wy (@) 656 ” Spaghetti naturally belongs with Italian skies, but it is now made in great quantities in the United States. It is made of wheat paste, which is forced from cylinders, in long slender tubes SA wire Ra en eRte Ae TES Above: Noodles are made in much the same way as macaroni and spaghetti except that, the paste is first rolled in sheets instead of being molded into tubes. It is then cut into va- The tubes are hung over frames to dry, care rious shapes. The addition of being taken that they do not touch each other. milk and eggs to the ingredi- In modern plants the work is done almost entirely ents of egg noodles, makes them by machinery and the drying by electricity a more expensive product 657 : © Press Iflus. Serv. In Hamburg, the Monsters which Walked the Earth The famous gardens in Hamburg,’ Germany, which contain life-size figures in concrete of the great sea and land monsters which inhabited the earth millions of years ago. Above is shown a group of marine animals of strange appearance and equally unfamiliar names The Stegosaurus, a veritable land dreadnought of pre- historic times. This creature carried a double row of blades or spines down its back. It was twenty-five feet long. More than twenty complete specimens have been found in the neighbor- hood of the Rocky Mountains The Tyrannosaurus, the larg- est flesh-eating animal that inhabited the earth. His bones have been found intact in the Bad Lands of Wyoming and in the sandstone district of Alberta, Canada. When the present Rocky Mountain district was a vast swamp the Tyrannosaurus reigned there supreme and_ unchallengéd in Prehistoric Times Are Re-Created in Concrete The Plesiosaurus, a marine monster which inhabited the earth about ten million years ago. He possessed a serpent’s neck, the head of a bird, the teeth of a crocodile, the ribs of a chameleon and the fins of a whale *; The Iguanodon, a dinosaur that reminds one of the kangaroo. Every bone of the monster’s body has been found in Belgium and England and cast in plaster. The fore limbs were com- paratively small, the large three-toed hind limbs being chiefly used in walking and jumping 659 93810 94} uO souT;}NO Jeon. BSulonposd 39M0} - ‘sat pun posds Bur: aI9UT i : Surms Sear org Suump ‘soyde1303 | 0 31ed ae p | JO Jed 9y} UO aInsodxa ,sajnuIUI U20EzJY B Jo - *Sulms pa3zy3y-Aypeorr309]9 ue jo poe euoqg eB ms epee Way soe ; ‘3 ak Te SO a 8 ihe FRE oA eR a MN i Z a > a ie) ra) — ~ = © oan ‘Of =| i ie Q, oe) Ee po!) ke a Spinnin Li Our Greatest Inventor Is Three Score Years and Ten ~ a o- ’ . — we os , Oe Re a t, . “a at . >. : 2 Celebrating Thomas A. Edison’s seventieth birthday at his West Orange, N. J., factory. From left to right are Henry Ford, Mrs. Edison, Mr. Edison, and Charles Edison, the inventor’s son. Beginning work at the age of twelve, as a newsboy on the Grand Trunk line running to Detrnit, Mr. Edison owes all his distinction and- advancement to himself alone. He has taken out more than a thousand patents. His greatest invention is the incandescent lamp, which has turned night into day, and which has given five million people their living, directly or indirectly 661 An Underground Summer Home Hewn out of About seven miles north of Fresno, California, an enterprising citizen has constructed a novel summer home under- ground. It is dug out of rock, locally designated as “hard pan,”’ which is imper- vious to moisture. In the picture above, the owner is shown in the entrance hall A near view of the entrance. "It is fourteen feet below the surface. There are sixteen rooms in all, honeycombing an _ under- ground area of half an acre. Most of the rooms have glass ceilings with provisions for ventilation. A young orange tree in first bloom graces the outer door-way the Rock Beneath the Above-Ground Residence € underground dwelling & grape arbor, sloping down to the entrance, which is fourteen feet below the surface. Here the bachelor receives his friends. The corridor js about eight feet wide and extends back about two hundred feet At right: One of the two lateral tunnels between the rooms. These tunnels are seven feet high and about three and one half feet wide. Every twenty-five feet there is a room which opens to the surface for light and ventilation. At the end of this tunnel are the kitchen and pantry At the approach of poison gas in the trenches a klaxon horn is sounded A *‘Honk! Honk!”’ in the Trenches Means ‘‘Don Your Gas Masks!”’ HE deadly gases which have been introduced into trench warfare as the equal if not the superior of exploding shrap- nel for exterminating an enemy, have necessitated the use of various kinds of gas masks, many of which have proved effec- tive. But it is inconvenient for the soldiers to wear the masks constantly. So, various mechanical devices have been used to give the alarm of approaching poison gas to enable the troops to put on the masks in time toavoid danger. Popular Science Monthly Massaging the Digestive Organs by Deep Breathing HYSICIANS agree that massaging the abdominal organs is at best a delicate procedure requiring the skill of a profes- sional in order to prevent more harm than good being done. And yet abdominal massage is recommended as a help or cure for various ills, especially for constipation. A method which is so gentle that no baneful effects could possibly result employs sys- tematic deep breathing as the agent. The diaphragm and the muscles of the abdomen share in the work of respiration and at the same time press rhythmically upon the intestines. In order to increase the pressure so that massaging of the intestines results, it is only necessary to breathe more deeply than is customary and to keep it up rhythmically. The patient should lie face downward across the bed taking from five to seven deep breaths a minute. A pillow under the abdomen serves to press the organs in so that the force of the breathing is felt more by the enclosed organs than by the stretching outer skin. Railroading in Alaska Is Still Far from Rapid HE photograph below shows the only method of transportation in the rich gold-bearing Iditarod region of Alaska, and this is probably all they will have for some time to come, although their outlet or con- nection is now a real railroad line instead of uncertain water transportation as formerly. Gold was discovered there about six years ago with the usual Ina French trench the klaxon horn, shown in the ac- companying photo- graph is used for the purpose, which gives an altogether new meaning to the fa- miliar ‘‘honk.’’ The masks are kept with- in instant reach, and so readily are they adjusted that when the alarm is heard the soldiers almost immediately be- resultant rush of miners and prospec- tors. The present rail- road consists simply of short poles for ties, laid on the mossy surface of the ground, without bal- last, and rails of sawed wood; but on it a tandem of stout horses with one driv- er can haul a tram car containing as much merchandise come unrecognizable under them and cor- respondingly safe. The transportation system which a gold- bearing district in Alaska boasts. track is composed of wooden poles as was formerly car- ried by a pack train of twenty animals. The Toledo’s baby moon is a ball of fire, eight feet in diameter. It is an advertising device Toledo Plants a Baby Moon in the Sky “IKE the Moon led astray in the Heaven’s wide pathless way,’’ wrote the poet Wordsworth many years ago, with- out knowing, of course, that in later years some emboldened Toledo folk would ac- tually abduct a young moon and take it to the top of a twenty-two-story skyscraper and fasten it there just for the sake of looking at it. It goes without saying that Toledo’s young moon is for advertising purposes, but the Toledo people get around that easy enough. ‘‘Doesn’t the real moon advertise the fact that there is a sun on the other side of the world?” they ask. And there you are. Fifteen miles out on Lake Erie, pilots of steamers can see Toledo’s moon. En- gineers on trains, passengers, automobilists, and everyone approaching the city, wonder what the big ball of fire is. Everywhere is heard the question, ‘‘What is that great light in the sky?” The baby moon is nothing more than a huge ball eight feet in diameter, lighted with eight hundred seventy-five-watt lamps, equivalent to seventy-five thousand candlepower. To operate the ball eighty horsepower is required. The ball has the appearance of revolving, due to a flasher which turns the current on and off, making the lights quiver. There is no word of advertising on or near the ball. Popular Science Monthly 665 sooesccemme ned How the tiny moon looks on a dark night on top of its twenty-two story building As a Lineman He Has Climbed Eight Hundred Miles HE next time you see a lineman scaling a telephone pole think of William Lane, of Rockford, Illinois, who has climbed over eight hundred miles in the last twelve years. Mountain climbing pales into in- significance compared with scaling tele- phone poles. It takes more strength to climb ten feet of pole with spurs and harness than it does to climb five hundred yards of steep mountain side. Lane’s average as a lineman has been twenty-five poles a day, or something like one hundred and ten thousand times forty feet. He has had several falls, due to poorly-fastened spurs and harness, but no bad ones, he says. The Story of the Machine Gun Peace-loving Americans invented the deadliest of modern weapons RECOIL PLATE FIRING PIN. CARTRIDGE By Edward C. Crossman WATER JACKET BARREL EJECTOR TUBE The water-jacketed Maxim. The cartridges are fired by means of webbing belts. They fire at the rate of from 300 to 600 shots per minute. HE machine gun is purely an American weapon, from the Gatling of black powder days to the latest feather- weight Lewis and Hotchkiss and Maxim. It is frankly and brutally a man-killing weapon. In Civil War days Dr. Gatling of Chicago evolved a seven-barrel gun to fire the army .45 caliber cartridge at the rate of four hundred or five hundred shots a minute. By the grinding of a crank, the seven barrels and the mechanism were revolved around their long axis. A barrel was loaded as it left the top position, the loading and closing of the breech being done on the half revolution from top to bottom position. At the bottom position the cartridge was fired, and on the upward turn the breech was opened, the cartridge extracted and the barrel left ready for the fresh cartridge by the time it came to the top. The operation was the same for each barrel, and the seven spun furiously around and around, spitting fire and death at a rate unheard of in those days. Thecartridges were fed from a drum or a hopper above the gun, dropping down for each barrel by the force of gravity into the grip of the loading mechanism. Later an improved feed was designed, the Acles, which fed in cartridges by positive motion, even though the magazine was placed at the side of the gun. No machine gun is fired very long The gun was used at different times in our Civil War but always manned by employees of the Gatling Company. Because of the poor ammunition of those days, the gun was often jammed, but it was extremely successful and formidable with good ammu- nition, and was the first machine gun of history. Even as late as the fight at San Juan in 1898 the Gatling was used, its fire helping to take the blockhouse on the hill. But our army was always suspicious of the gun, not knowing just how to useit. It- was too heavy to accompany infantry, and its range was not long enough to be used with artillery. _ The French in 1870 had the same trouble learning what to do with their first machine gun, -the mitrailleuse. That frightful weapon was as heavy as a field gun, and looked like one, so the French used it with their batteries in spite of its short range. Then the Prussian long range field guns would knock the mitrailleuse clear over into the next county without having to fear a reply from the faulty infantry cartridges which were its food. The mitrailleuse—which means merely — a ‘‘grape-shooter’” from the fancied re- semblance of the strike of its bullets to the impact of a charge of grape-shot—had thirty-seven barrels mounted in an iron 666 Popular Science Monthly casing that looked like the barrel-of a can- non. The infantry rifle cartridges used were arranged in an iron plate with thirty- seven holes in it, and which formed the breech end of the barrels. “The plate carrying the thirty-seven car- tridges, was slipped into grooves in the movable breech block, the block was shoved up until the cartridges entered the barrels and the plate fitted snugly at the breech-end of the barrels, and then the thirty-seven shots were fired by the turn of a crank, which re- leased one after the other the little ham- mers in the block op- posite each cartridge. By giving the crank an en- tire and swift turn, the thirty-seven shots were fired in one second, a slower turn of the crank of course fired the car- tridges at a correspondingly slower rate. Because of this peculiar firing rate, the gun had a menacing, growling report, a sort of “Gr-r-rr-ump,” that the Prussians quickly learned to identify. After firing, the breech was © Underwood and Underwood, N.Y. Army men practicing with a Colt machine gun found in a Sulu store 667 The Gardner and the Nordenfelt were more so-called machine guns of hand oper- ated type. Not until the coming of the Maxim did the machine gun become the frightful weapon that it is now. Following is a list of the modern machine guns: Maxim, used by England and Germany and Russia—Ameri- can. Hotchkiss, used by France and Japan—American. Benet - Mercié, modifica- tion of Hotchkiss—Ameri- can and French. Colt, used by Russia and other nations— Browning, an American. Lewis, used by Eng- land and France, an American army officer. Schwarzlose, used by Austria—German. Those most commonly used and most efficient are of American design from start to finish. The celebrated “Pom-Pom,” used by the Boers against the British, and re-chris- tened because of its peculiar rhythmic pounding noise, was a Maxim-Nordenfelt, firing cartridges six inches long, twenty-five to the belt, and using a one-pound high ex- plosive shell. It was merely a larger machine gun. opened, the plate carrying the thir- ty-seven empty shells was taken out, and a fresh, filled plate was slipped in the block. This was the first use of a ma- chine gun in war, and because of the French Army’s faulty use of it, little harm was done. It was never so effective as the Gatling. These guns were not really auto- matic machine guns; they were operated by hand power, they were heavy, and they were mounted on wheels and exposed to return fire. © fat. Film Serv. gun. PS ie Sin) met The Maxim is undoubtedly the best known machine It is water-cooled and heavier than others The British had little use for the machine gun, save in the navy, where it was used with large caliber bullets of steel to repel torpedo boat attacks prior to the days of modern quick- firing navy guns. But when Kitch- ener took. com- mand in South Africa he carried with him plenty of machine guns —Maxims. At Omdurman, the greatest and most one-sided slaughter of modern times, where spears and courage were pitted against modern arms—the chattering Maxims proved by the piles of savage dead, to be 668 the most frightful of modern weapons. But when the Japanese and Russians learned to use machine guns as they should be used—in touch with the infantry at all times, civilized Europe woke up to the possibilities of the chattering demons. When the great war broke out, the Germans had more than fifty thousand machine guns of Maxim type, aside from those used specially for fortress defence. The modern Popular Science Monthly gun of Benet type is ruined in five minutes’ continuous firing, which means without any more pause than enough to insert filled clips. Each shot develops a temperature of five thousand degrees. Any of these machine guns, fired until it is good and hot, which does not mean neces- sarily for five minutes, or more than one, will fire a cartridge inserted into the barrel, from the heat alone. The Colt gun when firing at a lower machine gun | ranges from the | automatic rifle form, such as the Lewis and Benet of our service, weapons weigh- ing thirty lbs. or less—to the weightier water- cooled Maxims and kindred guns, such as the Germans use. All of them ope- trench fighting in the Balkans. rate the same * Photos © Int. Film Serv. way. They fire at the rate of from three hun- dred to six hun- dred shots a min- ute so long as the ammunition sup- ply is kept up— and all of them use the ordinary infantry cartridges of the army operating them. So long as the trigger or firing bar is held back, the gun continues to fire. Most of them can be used as single shots, a shot to each pull of the trigger. The Colt, Maxim, and Schwarzlose, feed their cartridges by means of webbing belts holding usually two hundred and fifty shells, and refilled by a special machine. As a rule each gun has several thousand rounds of shot loaded in these belts, car- ried with each gun. The Benet-Mercié and Hotchkiss of older type, feed their shells through flat clips of steel, holding thirty cartridges in each one. The Lewis feeds by means of a drum of fifty shells, which when emptied can be replaced in an instant with a filled one. No machine gun is fired continuously. It will not stand it, and the damage is worse when the gun is of the air-cooled variety instead of water-jacketed. ‘The air-cooled British troops using a Lewis machine gun in the A Lewis machine gun taken apart. The maga- zine (shown in photograph above) is missing rate than four hundred shots to the minute, has an unpleasant habit of firing - the shell being ’ inserted into the barrel, from the heat and before the action is en- tirely closed, pro- ducing discon- certing effects on the mechanism and gun crew. Machine gun fire is by short bursts of shots, ten to thirty; _ then the firestops and the gunner relays the gun onthemark. The Germans use them in pairs, alternating their fire, one backing up the other in case of a jam. The German front is solid with machine guns. The British tear to bits their trenches and make a waste of their en- tanglements, but after the fire has lifted and the British start forward, It fires fifty shells A machine gun © fitted with seat and pedestal for — horizontal firing Popular Science Monthly out come Hans and Fritz, dragging their Maxims, and then the rest of the crew from their dugout shelters—and the machine guns operated by a little handful of men are likely to win the battle against hundreds of infantrymen. The machine gun is equivalent to the fire of from fifty to one hundred men, but as the gun is usually mounted on a stationary foundation, especially in the German service, and holds its position, not being affected by nerves or fear, and being worked by cool, desperate, picked men, it is really equal to far more than that num- ber, because of the greater effect of its fire. The German Maxim is mounted on a combined tri- pod and sledge, <3 and with mount 5 and gun com- © Int. Film Serv. plete weighs seventy-five pounds. It is steadier than the light guns of the French service, and still when it is turned over on the sledge-shaped part of the mount, the crew can haul it speed- ily out of harm’s way or to a new field of activity as fast as the French can move their lighter but clumsier-to-carry Hotch- kiss gun. Just at present the Germans are the machine gun artists of the civilized world, and the guns play the most important part A machine gun knocked down, ready for transportation. It weighs about seventy-five pounds with its mount 669 in holding their line on the west front. The other day an American chief of ord- nance of our army, asked for funds to build seventeen thousand machine guns—there being about one thousand on hand! One of the marked features of the ma- chine gun is the encouraging effect on the troops on its own side, and the terrifying effect on savage peoples. Not long after the Spanish War, the American Army au- thorities found a job on hand on the island of Sulu, subduing a band of a thousand or more men, wom- en and children of .the bandit variety, who had ensconced themselves in the crater of Mount Dajo, a high and precipitous iso- lated peak that had been an ex- tinct volcano. Lieutenant Leighton Powell, who was with “Machine Gun Parker’ at Santiago and had caught the fever from the famous American believer in that sort of weapon, found, neglected and hidden in dust and cosmoline, a Colt machine gun in the warehouse at Sulu. He asked and received permission from the scoffing infantry officers to form a machine gun section and to take the gun up the mountain with the attacking force. He gathered together a group of infantrymen, made gunners out of them, drilled German soldiers transporting one of their machine guns and mount to a new field of activity them faithfully and hard—only to be left behind by the main body of troops when the columns departed for the attack. That evening, how- ever, there came a messenger for Lieutenant Powell to bring on his blamed machine gun—the army had found the mountain a tough-looking nut tocrack. So joyfully they packed up the Colt and trekked for the big mountain. That night two columns crept up the mountainside. Powell made a Moro sandwich, with a Moro carrying ammunition or machine-gun part, then an American gunner, then a Moro, then an American, and so on, to keep the natives from sneaking off in the dark. Every now and then the 670 Yankees would poke the natives in the back to make sure all was serene. The Americans rushed the cottas de- fending the trail at daybreak, and found themselves on the edge of a bowl at the mountain top, some four hundred yards across, packed with huts and Moro cottas or forts. Also several hundred enthusiast- ic Moro bandits were pot- ting at the Americans from every part of the crater. Presently in the midst of the fitful crackle of the rifle fire, there broke out a sound no Moro had ever heard, the vicious and sustain- ed chatter of the Colt machine gun. From that instant, the Moro fire slack- ened, while the ma- chine gun _ searched methodically the light bamboo cottas of the Moros, the bullets rip- ping through as fast as spray from a hose. I saw a picture of some of the cottas and trenches taken a few hours later. It was not a pretty picture— particularly in view of the fact that women fought with men, and there had been no chance to pick and choose in the marks for the American guns. Even after such an experience as this the American Army had little faith in the machine gun. Even the Russians saw the beautiful qualities of the Gatling and bought more Gatling guns than all other nations put together, to use on the natives of Asia who~ objected to the Russian colonizing and exploring. When a-Turco- man charge started for the Russian lines, the Gatlings calmly and methodically spread Turcoman riders and horses all over the vicinity. The field gun and the giant howitzer may masquerade as mere engineering ap- pliances for smashing up trenches, the infantry rifle can establish a weak sort of an alibi as being partly a weapon of self- defense in that it can parry an opposing bayonet, but the machine gun is unblush- A Moroccan chief explaining the working of a machine gun to some new mystified army recruits Popular Science Monthly ingly a frightful machine for killing men. It has not the slightest utility from any other standpoint. Although America is notoriously a non- military country, and although the market for man-slaying weapons has always been best abroad, and although the great arsenals for mili- tary weapons were across the water, yet it has been America which has evolved this most awful weapon and placed it at the disposal of modern belligerents. The greatest man- killing machine on earth, the chattering destroyer of whole battalions, the most formidable defender of the German lines, is not only of Amer- ican design original- ly, butis of American design in its varia- tions as used in the present war. Yet it is undoubtedly true that the equipment of the United States Army contains fewer of these guns than that of any other nation among -the great powers. A New Sugar Flour from Northern France HILE the brainiest men of Europe are working over the war situation, new geniuses are arising in the ranks of the manufacturers, farmers and ordinary workmen to solve the food supply prob- lems. In Northern France a new flour is being made from sugar beets. It is used for bread and for cattle food, as well as for certain brewing processes. . The fresh beet pulp is. poured into a vat into which currents of warm air are introduced for drying. Then it is passed through a series of gratings which rotate one above another. After this the pulp is delivered into compartments in which the temperature of the air is gradually in- creased to about 250 degrees Fahrenheit. It is then sufficiently free from moisture to be pulverized and used as flour. A New Air Propeller of Steel and Enamel The framework is made of one piece of thin steel over which the glossy coating is baked plane or airship is made like a pair of blades on an ordinary electric fan. They are, however, about a dozen times larger, and capable of throwing back a column of air several thousand times more powerful. When such a propeller is revolved at high speed, it will push with tremendous force against the air; and with equal force will the aeroplane be pushed ahead. Its opera- -tion is just like a propeller pushing a ship, only that the aeroplane propeller works against a very much lighter substance. The first aeroplane propellers were copies of windmills. Their blades were of canvas stretched on a wooden framework. They were, however, -very inefficient. The next step in advance was made when aluminum blades were riveted to steel arms which projected from the driving- shaft from the motor. But the great defect in both of them was their lack of clean-cut outline. Unless a propeller blade is made rigid and in one unbroken piece, the slightest projection or un- evenness serves only to churn the air. At the high speed at which the propeller re- volves, the vio- lent churning will hinder rather than help the — aeroplane a in its progress. Be oa The solid one- pS piece wooden propeller, in- vented by Hi- ram Maxim over twenty-three years ago, practically elimi- nated this defect. Its outline is unbroken and its surface is polished as smooth as glass. Nothing in the world is given so high a finish, and its clean-cut blades churn ‘ee screw propeller of an aero- any variety of weather The die wherein the inner framework of the propeller is pressed into shape from thin sheet steel the air very little. It has one great draw- back, nevertheless, in that it is affected by the weather. Changes in degrees of moisture, heat and cold warp the propeller in time. Asa matter of fact, the wooden propeller of one of our military aeroplanes which ran the risks of the Mexican climate was warped suddenly while the aeroplane was high in the air, and came to grief. The weather-proof pro- peller, the next step, has only recently been developed. It consists of a_ thin one-piece steel framework upon which a glossy coating of lacquer is baked. The steel is pressed into just the right form by a. huge steel die. The sur- face of the steel is treated with chemicals. This makes the steel spot- lessly clean so that it can ‘take’ the ~~ lacquer. A heavy The lacquered steel is as light coating of the un- as wood and will withstand baked lacquer is then spread evenly over the entire surface of the steel. The two substances are forced together under great pressure and are then brought to a high temperature. . The steel and the lacquer amalga- mate and one rigid piece is formed. The light lacquer strengthens the inner framework, and the propeller itself is considerably lighter on account of it than if it were of solid steel. When the pro- peller is cooled and polished, it forms a surface as smooth as a lacquered Japanese box. This spells effic- iency. The weather-proof quality of the lacquer also enables the propeller to with- stand all climates indefinitely. 671 The “Missing Link” Among the Fishes It has lungs like a land animal and leg-like fins HAT kind of a fish is this that the \ \ American Museum of Natural His- tory has received from Africa? To be sure it’s dead and older than Adam and Eve. But look at it. It had perfect gills and lived in the water when it could, swimming about and enjoying life to the utmost. But when a home in the water was not available on account of the drying up of the rivers at certain times, it bored down into the mud, wrapped itself in a kind of cocoon and lived there, breathing air through a per- fectly good pair of lungs until the floods came and washed it out. They call it the “lung fish.’”’ Its skin structure, its skeleton and brain so closely resem- ble certain land types that it is conceded to be a definite connect- The summer home of the lung fish, into which it burrowed while the earth was still moist in the river bed. had need for lungs until the floods came ing link between the true fishes and the four-footed land animals. It has two sets of fins, which are so placed that they are slightly suggestive of legs, especially the hind ones. The American Museum’s specimen of the lung fish was found in a clod of ‘earth in which it had encased itself in its cocoon, a capsule of papery texture formed of hardened layers of - slime secreted by its+ body for the pur- pose. At one point There: it Photos American Museum Natural History Above: Burrow- ing deep into the earth as the hot, dry season approached. A breathing hole was left through which a current of air was obtained The active lung fish as it looked in water. Note the leg-like fins and the breadth of the disappearing tail. ‘Something similar is seen in the tadpole 672 Popular Scienee- Monthly of the cocoon it had formed ‘' a tube of this hardened slime. This led to the outer atmos- phere and furnished air to the lungs while the fish slept there. The clod was cut from the river bed and was carried thousands of miles, but nothing disturbed the inmate until it was placed in tepid water which melted the cocoon. Then _ the fish awoke, to find itself in the aquarium in the hall of fossil fishes in the Museum; but whether or not it realized any difference in its environment could not be ascertained. Perhaps it merely supposed it had reached the next stage in its evolution and was sur- prised that the change was so slight. A Stencil-Cutter Is the Typewriter of the Shipping-Room Nips old pot and brush method of painting addresses on cases to be shipped has been superseded by the use of stencils in the majority of business houses. The addresses are cut out on stiff paper by the cutter, and the stencil is placed against the case. The paint is applied through the cut-out spaces. In the letter-cutting machine the punches and dies which stamp the letters are carried on circular beds, one bed above the other. One bed carries the punches and the other carries the dies. The paper is placed between the two. The beds are rotated by _a wheel until the proper letter- punch isin posi- tion. This’ is indicated Ze when the a st pointer on the wheel stops in front of the corresponding letter on a sta- tionary scale. The punching-lever is then pressed, and the punch and die come together and force the outline of the letter through the paper. Stencils made in this manner cost but a tenth of a cent each. Each stencil can be used many times. They are so clear-cut and legible that some steamship companies will notaccept packages marked in anyotherway. The stencil is prepared by forcing letter- shaped punches and dics through stiff paper A Toy Field Hospital for an Object Lesson MINIATURE camp with tents about one foot high was erected during the past summer for demonstration purposes in the center of a real camp of about 18,000 troops covering nearly 1,000 acres of ground at San Antonio, Texas. It was made and set up by a field hospital company of the National Guard of Florida, just to show how a model field hospital should look. The tents were made of regulation khaki-colored canvas with the. pre- scribed number of guy- ropes and tent- pins. They included the pyr- amidal tents such as are used by the staff of a field hospital com- pany and the large wall tents of the so- called ‘‘hospital”’ type, which house the wards for the patients, and the operating rooms. Miniature army escort wagons that were made according to scale were parked at one end of the model camp and near them was a picket line where a number of toy horses and mules stood with their noses buried in tiny bundles of hay. Within the ward tents were cots and other furnishings and in front of the camp stood a flag pole from which a national emblem and medical corps flag fluttered in the breeze. Even the smallest details of the regulation hospital camp, were faithfully reproduced. 3 That Cloud—How Fast Is It Drifting? How statistics are gathered upon which meteorologists base their theories concerning the atmospheric circulation OW high H are the clouds? How fast do they move? In what directions? Answers to these questions are of great interest to the student of the atmosphere, because the clouds furnish the same kind of information about the move- ments of the air at high levels that we ob- tain near the earth by means of weather - vanes and an- emometers. Accurate measurements of the altitude of clouds may be obtained by observations made simul- taneously from two points with theodolites, or by a corresponding photographic Information on this subject method. A misror instrument for measuring cloud motions The nephometer,. a convex mirror, the surface of which is divided by lines into ten sections, is used to determine degrees of cloudiness or relative areas United States. has also been ob-- some fixed object. tained by noting the location, with respect to the ob- server, of the shadow of a cloud on the ground, in conjunction with the angular alti- tude of the sun. These ‘data give us the base and the angles of a of Paris. cross piece 314 feet long, to which a number: of equidistant vertical spikes triangle, of which are attached. the altitude may The rod is be computed trig- mounted 674 onometrically. The altitudes of clouds range all the way from nil, when the cloud rests on the ground and constitutesa fog, up to about seven miles, in the case of the feathery clouds known as Cir rus.’ ae The instru- ments used. in observing the motions of clouds are called- nephoscopes,and - these are of two _ principal. types, distinguished as reflecting nepho-. scopes and direct-: vision nepho- scopes. In the former the movements © of the cloud are observed in a black mirror, and this is the type commonly employed in the In he latter the cloud’s motion is observed directly, with relation to The picture on the following page repre- sents an example of the second type; viz., the ‘‘comb_ nephoscope,”’ | invented by Dr. Louis Besson, This consists of an upright brass rod about 9 feet long, bearing at its upper end a The type of measuring in- : strument known as the in a Marvin mirror nephoscope Timing the Clouds to Determine the Weather The ‘Comb Nephoscope.” It consists of an upright brass rod about nine feet long, bearing at its upper end a cross-piece to which a number of equidistant vertical spikes are attached. The observer turns the cross-piece until the cloud appears to travel along the line of spikes, and notes the time it takes to pass from spike to spike. This forms a basis from. which he reckons 676 vertical. position by means of -rings: and clamps screwed into a:tall.post in'such a manner that it can rotate freely... Its height can also be adjusted so that a fixed point on the rod is at the level of the observer’s eye. In using the apparatus, the observer sta- tions himself in such a position that the cloud selected for observation is seen in the same straight line as the central spike. He ‘then turns the cross-piece until the cloud appears to travel Popular Science Monthly What Is a Man? Break a Thousand Eggs and You’ll Have His Contents HAT is) a man? How much is he worth from a scientific viewpoint? According to one way of looking at it a man is worth about $2.50 a day from his shoulders down and anywhere from $50,000 to $1,000,000 a year from his shoulders up. This may be said to be the estimate of the average successful business man. The scientist, along. the line of spikes, while he remains motion- less. The cross- piece will then be parallel to the line of motion of the cloud, and the direction in which it points can be read off on a graduated cir- cle which is fixed to the rod. The rod may be turn- ed by an observer standing at some distance away from it by means of two cords tied to a second short- er cross-piece at- tached to its lower extremity. The observer notes the time the cloud takes to pass from spike to spike. The dis- tance between two spikes is _- however, looks at the question from another angle. According to him a man is worth $2.45 for illumi- nating purposes, since a man weighing 150 pounds contains about 3,500 cubic feet of oxygen, hydrogen and ni- trogen in his con- stitution, which at seventy cents per 1,000 cubic feet equals the price above. Also a man contains enough carbon to make 9,360 lead pencils; enough phosphorus to make 800,000 matches or enough to kill 500 persons, and enough water to fill a thirty-eight quart reservoir. Furthermore, known, and also the altitude of the cross-piece The observer is sighting the image of a cloud reflected into the mirror from an artificial pool of water below the window, to determine its height it makes no dif- ference how sour above the ob-. server's eye. A rudimentary knowledge of geometry tells us that the ratio of the latter distance to the former is the same as the ratio of the cloud’s altitude to the actual distance it travels in apparently passing from one spike to the next. The altitude of the cloud may be assumed to be the average altitude for a cloud of its type. ee The nephometer, shown in another.,.pfc- ture, is used to determine ‘‘degree of cloud- iness,”’ or relative area of the sky covered by clouds. a man may look he contains about sixty lumps of sugar, a great deal of starch, chloride of potash, magnesium, sulphur and hydrochloric acid in hissystem.: There are fifty grains of iron in the blood:of an ordinary man, enough to make one spike large enough to hold: his weight. What.isa man? This is the sbmewhat cynical answer of one scientific man: “Break the shells of 1,000 eggs into a huge pan or basin and you have ingre- dients from which to form him from his toe nails to the most delicate tissues of his brain.” Popular Science Monthly 677 In the center is a tendril showing the windings in two directions and the hook in the center. Why the Tendrils of a Plant Grow in Two Directions HEN a climbing plant has attained such a height that,its weight will prevent it from growing upward it begins to throw out tendrils which grasp other bodies for the purpose of support. Somehow the plant knows where a neighboring object is to be found and throws out tendrils in that direction. At first the tendril is straight, but as the object to be grasped is approached a little hook is formed to act as a catch. The moment this has been accomplished the tendril begins to coil up, going first from right to left, then forming a loop and going from left to right. Such a tendril is so elastic that there is little danger of its snapping off when the vine is subjected to the sudden strain imposed by the alighting of a bird or the blowing of a sudden gust of wind. But why should the tendril grow in two directions? This is a question which has puzzled many. It is answered in the illus- tration above. In the center of the illustration is a photo- graph of a tendril, showing the two coils in opposite directions and the loop between them. Now let us take a narrow paper ribbon and coil this around a pencil as at the She is attending strictly to business and embroidering at the same time At sides the principle is illustrated with a strip of paper over a pencil left of theillustration, meanwhile holding the unwrapped portion firmly between the fin- gers. For every turn we make around the pencil, the other portion of the ribbon will make a corresponding twist. If we were to continue the process the twist would finally become so tight that the paper. would tear. If we make a loop in the ribbon, as at right of illustration, and wrap the ribbon in the opposite direction on the pencil it will be seen that the twist is uncoiled. This is the principle involved in the growth of the tendril—LEHMANN WENDELL. A .Switchboard Operator Finds Time to Embroider HE accompanying illustration shows how a busy telephone girl proves the truth of the old axiom, “Where there’s a will there’s a way.” She has had a clamp attached to the edge of her switchboard, to which is fastened a hooked ring to hold her embroidery frame. She has only to make her connec- tions when a call is received, and_ then *) her hands are free. + She can talk through the mouthpiece while her hands are busy with the needle. In this way she not only fills her ‘‘hope chest’”’ without wasting her employer’s time, but she re- lieves the tedium of. the hours and the nerve strain. 678 Popular Sctence M onthly The Corrugated Wood Block for Street Paving HE corrugated Clearing a Crippled Car from Railroad Tracks HEN a car wood block marks an important advancein the manu- facture of paving materials. One side and one end of each block are corrugated or grooved in the direction parallel to the grain by a spec- ial machine. . These grooves immediate- ly adjoin each other. The dividing lines are of almost knife- like sharpness. The particular advantage of cor- breaks down on a busy road, it is of first importance to clear it out of the way so that traffic may go on undis- turbed. Thecaritself can be repaired when it reaches the barn, so that the first prob- lem is to get it there as quickly as pos- sible. For this pur- pose, the master me- chanic of a Western - traction company has devised a piece of apparatus which can temporarily take Ba NZ Ls IN CURB 4 I" ee PAVEMENT FILLER V CORRUGATED CREOSOTE BLOCK = qT The corrugations auto- matically provide the | space for the filler k——3 —— rugated block lies in the fact that the blocks may be laid snugly together, course on course and block on block, without fear of displaced alinement due to expansion from temperature or moisture. In laying the ordinary block the workmen must attempt to provide a space between the courses and between the blocks in the courses. With this newly invented block the corrugations automatically provide the necessary space for the pavement filler to flow to the bottom of the block, effectually sealing the pavement against moisture. Under certain con- ditions wood block has a tendency to expand. When this con- dition exists with corru- gated blocks, the knife-like edges crush or bury them- selves in the adjoining blocks, relieving the pres- sure at once. Each block has its own expansion joint. Fi z 4 s car Eee Hi . h The workmen drive the courses the place of a broken snugly and place each corrugat- : : | = ed block without having to axle on a peed ai make calculations for expansion apparatus is merely an auxiliary truck with small railroad wheels rigidly held apart so that they properly fit into the rails. When a car has broken down, an emer- gency car equipped with a set of these trucks is immediately sent out. The crippled car is lifted up by heavy screw- jacks at the end where it has broken down. The auxiliary truck is then run underneath the broken axle, the car wheels are fitted into the frame, and the whole apparatus is strongly fastened to the car by means of heavy chains. The car then runs back to the barn by its own power. When the car breaks down, an auxiliary truck with small railroad wheels is run under the broken axle to support it Popular Science Monthly A Hollow Tile Building Block Which Is Waterproof we take the word of the hollow ‘tile enthusiasts, brick houses are disease breeders, since brick does not keep out moisture or the cold and does not retain heat. Another argument against its use is that it permits water to go through to the inner surface of the wall, making it necessary to use laths or other means to separate it from the plaster. Laths are not used with hollow tile. The widespread popularity of the hollow-tile building block in prefer- ence to brick in the construction of our modern buildings is said to augur well for its exclusive use in the future. Of course, there are many different kinds of building blocks of the hollow tile type, all claiming to be waterproof and weather resisting. The one illustrated is the invention of Halver R. Straight, of Adel, lowa. Between a layer of cement or mortar and each rib there is a dead-air space which prevents the flow of water or the transmission of moisture. The inventor claims that if water enters the vertical mor- The kerosene oven. A copper tube brings the oil from thenearby tank. A hand pump supplies pressure Army Cooks Prefer Kerosene to Wood for Fuel RMY camps along the Mexican border are experimenting with kerosene as a fuel substitute for wood in the field bakery ovens. In localities where wood is scarce, oil is much cheaper and more reliable than wood, and there is no danger from sparks. A simple burner is used. It consists of a piece of pipe extending the length of the fire box and con- tar joints be- tween his tiles it will not flow toward the inner surfaces of the wall, but will be conducted back to the outer sur-_ face. Each tile contains two re- cesses for cement or mortar, a rib, a groove, and a top and bottom surface which in- cline downward from the groove. The rib of one tile - fits into the groove of another, so that the blocks can be alined. with exact- ness. Furthermore, the tile does not need to be hammered or pounded upon to force it down in its proper position. Above: A house built of hollow tile. of hollow tile through which moisture cannot enter ; ALINEMENT ‘ MORTAR GROOVE CENTERING RIS — taining a num- ber of holes through which the oil is forced under pressure. A flexible copper tube brings the oil to the burner from a_ nearby supply tank hold- ing about fifteen gallons. Pressure is applied to the oil by means of a hand pump, the amount being deter- mined by a gage. By burning oil an oven may be brought to a baking tem- perature in less time than when wood is used. The baking can be started at any time on short notice and the bakersdonot have to contend with wet or green wood. Below: A type GROOVE FOR ACCURATE =rMINIMUM MORTAR JOINT ON OUTER FACE OF WALL * Vane. 680 How the German Aviators Land Safely at Night with their Aeroplanes ECAUSE of the great danger in making a landing at night the aeroplane is preeminently for use only by day. On the warring fronts in Europe there are some- times flocks of aeroplanes in the air at the same time. But when the sun goes down the aeroplane goes down with it, usually, to stay in safer regions for the night. But for all the Popular Scvence Monthly When the Cows Go on Strike, Try Artificial Milk LMOST any natural product can be imitated. In the matter of food imita- tions, the original article is first carefully analyzed and its constituent elements noted. These elements are usually ob- tained from vegetables and minerals for the substitution. In fact, the science of substitution is becoming a great factor in modern industry. danger connected with night flying there are many aviators intrepid enough to ven- ture forth in the dark. .-In . fact, the problem of making a_ safe landing at night has been solved by the Germans in an ingenious manner. In the center of the landing field a large, In England an artificial milk is being manufac- tured which is claimed to be both wholesome and inexpensive, so that now the market is not whollydependent upon the product of the cows. The artificial milk is made from pea- nuts, soya beans, sugar, water and mineral salts. white light is placed, sunk in a pit in the ground and covered over ye with a sheet of thick glass to-bear the weight of the.“ Gx Ce aeroplane should it pass over it. Sunk in the ground at a distance of about two hundred and fifty feet from this white light are four red lights corresponding to the car- dinal points of the com- pass. Mounted on a mast or tower at some con- venient point is a wind Subterranean cables lead from it to each of the red lights. : At night the central light glows con- stantly, while the red light in the direction of the wind that happens to be. blowing also shows, telling the aeroplane. pilot of the wind conditions where he is about to land and enabling him to make his own calculations of the field, using the two lights as a working base from which to draw his diagram. The lights are altered every now and then to prevent enemy airmen from using them as guides. How the An aviator making a landing at night, with the white and red lights on the field below to guide him Tw nee aii, d vane is -con- nected with the red lights by means of underground wires About four hun- ‘dred grains of potassium phos- phate or an equivalent of sodium phos- phate is dissolved in two hundred pints of water at 176 degrees Fahrenheit. Enough sugar is added to give four and five tenths per cent to the finished product. Forty pounds of meal prepared from the nuts and beans is stirred in. The solution is boiled in a steam-jacketed pan;. then it is subjected to the operation of a vacuum pan, and lastly it is treated with a culture of lactic bacteria until the required acidity is obtained. After it is pasteurized and cooled a small per- centage of citric acid is added. The milk thus produced may be con- densed and sold in cans, or dried and pow- dered, or sold as a liquid in bottles. The addition of nut fats will give a certain pro- portion of cream. By using sufficient lactic bacteria the product may be cultured to give a table cream or a soured mass for making cheese. A milk made from soya beans has long been in use among the Chinese. a ae et am Popular Science Monthly ) i: Jeweler’s Daughter Wears a Potato Necklace ATHER around, ye wealthy farmers, and gaze upon the first potato-neck- lace! You will perceive that the poor city folk are at last recognizing the true value of your commodities and assigning them a more con- spicuous place in the scheme of things. This costly necklace was - made by a Cincinnati jew- eler who experienced much difficulty in se- curing enough of the gems to complete the rare bit of jewelry. You will observe that the largest of the potatoes jis studded with diamonds. The egg suspended from it is also supplied with them. No less than 10,000 persons were satisfied with only a look at this potato- necklace while it was on ex- hibition in the show-window. No one asked its price. The potato Testing the Operation of Wooden Feet and Legs RENCH surgeons, in collaboration with manufacturers of artificial limbs, have made remarkable progress in their endeavors to provide mutilated soldiers with satisfactory substitutes for their lost legs. Some of the artificial legs devised, however, tire the user too quickly or cause raised to the highest degree of importance and studded with ‘“‘diamonds”’ 681 objectionable chafing or perhaps wounds. A Mr. Amar has recently discussed before the French Academy an ingenious invention called the dynamo-graphic side- walk, which promises to be of great ser- vice in the testing of artificial legs and in determining whether new construc- tions of such legs are free from the ordinary defects. Its pur- pose is to record accurately all movements of the foot during walking, their char- acter as well as_ their intensity, so that it will be possible to ascertain accurately the working of a leg and to choose a type of artificial leg best suited to the in- dividual for whom it is intended. The apparatus con- sists chiefly of two boards (each about eight . and one-half feet long and about ten inches wide) arranged side by side, but independently of each other. These boards are supported by a system of joints, springs and levers in such a manner that they will re- spond to the slightest pres- sure exerted on them, not only vertically, but longitudinally and laterally as well. These pressures will be received by the respective levers in the exact proportion of their intensity and transmitted to rubber bulbs, which in turn act by means of pneu- matic tubes on recording drums. The two boards being independent of each other, the movements of each foot will be conveyed separately to the respect- ive levers, which resolve them me 5 Wat * Pe ~ RECORDING DRUM RUBBER TUBES FOR TRANSMITTING THE Se EF oe eS Ft into their several components and transmit the result of this analysis to the recording devices, of which there are four for each foot. It will thus be easy to read off the vertical pressure of the leg when it comes to rest on the board, the rearward push of the foot before throwing the body forward, and the in- ward and outward pressure it The device records every movement of the foot during walking, so that it is possible to determine types of artificial legs best suited to special needs of cripples exerts. The data thus ob- tained are complemented by time measurements. The lower portion of the image is of gray rock, but the crown is of red volcanic tufa The Mystery of the Stone Giants in the Pacific HE mystery of the stone giants of Easter Island—a lonely mountain in the Pacific—will, perhaps, never be solved. Some of the giants were between thirty-five and forty feet in height. They originally stood on huge Popular Science Monthly somewhat out of proportion to’ their restricted areas. It is well known that the inhabitants of the island were at one time ferocious cannibals, and mention has been made by various navigators of fierce tribal wars, the opposing factions having ap- parently tried to annihilate or devour each other. The result has been that the island is practically depopulated and the statues or idols have all been thrown down. Not one now stands in its original position. Several of the smaller figures have been transported to museums. The lower por- tion of the image in the photograph is hewn out of gray basaltic rock but the crown is a striking red volcanic tufa. The features do not suggest either the Indian or the African; so the race to which the sculptors belonged is as hard to determine as the meaning of their work. An Indian ‘‘Corn Mill’’—Their Nearest Approach to a Factory P spite of the fact that one is irresistibly inclined to sympathize with the Ameri- can Indian and to consider him a some- what abused and deceived creature, a thoughtful person must admit that the lack of progressiveness on the part of the Indian was responsible for his loss of place. The accompanying photograph shows a busy mill, where the Mono Indians ground their corn into meal with stone pestles, in the same manner as their ancestors did for countless generations. Holes were dug out in the clay and baked dry and hard. Then the acorns or platforms along the coast, in rows, looking out to sea. Thus they are describ- ed by various navigators who first noticed them about a century ago, though what they represent, grains of corn were shelled and ground to pow- . der by the wom- en with the heavy stone pes- tles. A number of holes in a spe- cially favorable spot, such as is illustrated, is the nearest the Indi- whether savage gods or departed kings, nobody knows. The theory is advanced by some scientists that the present Easter Island is but the remaining apex of a much greater body of land that has sunk beneath the waters. This, of course, is merely specula- tion. The great statues, however, seem The holes are from a few inches to about two feet in depth and many of them still contain the pestles ans came to com- munity work. Even here, each woman ground her own private supply. There was no specializing in the work nor commercial exchange either of labor or’ of commodities. This mill is located in the foothills of the Sierras, over-looking the San Joaquin Valley. “Bullet-Proof Rooms, T'wo Dollars per Day” For one dollar extra you can sleep. in peace in this hotel on the Mexican border * = 4 a Sea OSS ew Mexican unburnt, HOTEL in Naco, Arizona, advertises its ability to protect its guests from “stray’’ bullets from across the Mex- ican border with the same pride that the boniface of a twenty-story hostelry in a big city calls attention to his high-speed elevator service. The proprietor of this hotel advertises sun-dried brick, while the other portion ve thick reinforced walls of adobe, the is of frame construction story structure of barn-like architecture. One half of it, that closest to the Mexican line, is of frame construction, but the main portion is built of adobe and has thick walls of sun-baked mud that are nearly as' hard as brick. A bullet may penetrate the frame portion but the adobe walls form an impassable his rooms’ on_ the writing paper of his establishment and he is _pre- pared to back up | his guarantee. | Chipped placesin | the adobe walls of his building give evidence of bullets which HOTEL NACO FM. ABRAM™, beorl - NACO, ARIZONA . ie es! “bullet-proof [fj a barrier. Rooms in. the adobe portion have been in de- mand whenever trouble has been impending across the border. Not only transients patronize them but also residents of the town whose have lodged in but have been unable to pene- trate the structure. Naco is a border town. Half of it is within the United States and the other in the State of Sonora, Mexico. One pitched battle and several lesser engage- ments have occurred during the past few years when revolutionist forces have at- tacked the Mexican portion of the town. Many bullets which failed to take effect on its citizens or their adobe houses found their way across the line and lodged in the homes of Americans. The houses on the United States side of the town are mostly of frame construction and more than one of the steel-jacketed bullets penetrated their frail walls and injured the residents. Naco’s one and only hotel is a two- Bullets taken out of the adobe walls of the bullet- proof rooms, which they were unable to penetrate homes are not bullet-proof. Taking Portraits against a Background of Soap Bubbles ROFESSOR_. Boys, of England, experimenting with bubbles, obtained some very large ones, which in the sun- shine changed colors so beautifully that he conceived the idea of using them as backgrounds for photographs. The large bubbles were blown with an ordinary bellows. The soap solution was heated and a large-mouthed funnel was dipped into it. The bellows, connected with the funnel, was then worked very gently. Bubbles with as great a circum- ference as two and a half feet were easily obtained. 683 684 Popular Science Monthly An Electric Signaling System for large, black easily distinguished letters. the Automobile The front and rear dials are wired up on the same circuit so that the arrows in both always point in the same direc- tion. Normally each arrow points verti- cally upward; but when it is desired to turn, the driver pushes a_ button on the control- board to turn them to right or left so as to indicate a turn in either direction. This is accomplished electri- cally by mounting each STATIONARY CORE Each arrow is mounted on a small cog-wheel which meshes [ OPERATIVE in a horizontal rack gear, the prrstsen _| POSITION arrow on a small cog-wheel, ends of which act as arma- {Zens LL: which meshes in a horizontal tures in two solenoid coils ““4_~*~* Wil, rack-gear whose ends act as en j armatures in two solenoid- coils. Energizing either coil magnet draws the rack into that coil Oris and turns the arrow that way. NEW type of automobile signal designed to make —‘NOvERATt the course of the car perfectly clear to the traffic officer or following vehicle, employs fairly large An Ingenious Cover and Press for arrow dials at front and rear to indicate he T s. Rack turns, and a mechanically-operated hand at the Tennis Racket the rear to indicate a stop. The device is FTER hard use a tennis racket warps. operated by electric current obtained from The gut becomes loose and saggy. To the storage battery now usually fitted on preserve the shape of the frame a racket cars and is manipulated from a small pressmay be employed. But the press does control-box mounted on the steering- not prevent the gut from being affected by column directly below the driver’s hand- atmospheric changes. Clearly, a moisture- wheel. proof cover is necessary. Each dial is glass-covered, like RING NUT Charles L. Bates, of Chi- a circular thermometer, to keep cago, Ill., has invented a out dust and dirt. Each is pro- combined press and covering vided with a large black arrow, which seems to meet all re- which stands out against a quirements. The clamping white background and is there- devices on most rackets pre- “fore discernible at a sufficient vent the use of any covering.. distance to avoid collisions But the inventor has de- at the rear. Similarly the — tennis signed his cover so that it is arrow on the front dial Sst clamped securely over ‘the suffices to signal to the racket at the same time the traffic officer the direction 57 press is tightened. The cov- in which it is desired to turn. femgie WOOD CLAMPING ering protects the handle as Both dials are electrically FRAME well as the face of the racket. lighted at night by means of A pair of clamping frames three small bulbs. The front lie on each side of the racket dial is held in front of the frame. After they are tight- radiator by means of a clamp bred cpa OLE =ened =by wing-bolts, as il- around the filler-cap. The rear az lustrated, the cover is dial is close to the license-plate, A combined fastened by means of eye- the electric bulb illuminating it press and Jets. The clamping frames ‘ ° E f 3 also serving to light up the white Sorarinn fee are provided with bolts large hand with the word ‘‘Stop’”’ in CANVAS the racket enough to fit any racket. Popular Science Monthly A Coffee Percolator That Never Runs Dry -~ PARTICULARLY successful con- trivance-for attracting attention to his store window was recently devised by a Chicago merchant. A coffee percolator was suspended in the middle of the window on a wire, tilted at a considerable angle. From its spout issued a dark brown stream of palatable- looking coffee, which flowed into a cup conveniently placed beneath. The curious part about the arrangement was that the supply of coffee seemed in- exhaustible. The percolator poured into the cup hour after hour, day after day without seeming to diminish the supply. How so much coffee could be con- tained in the small pot wasa mystery. The vessel hung on the wire entirely free from contact with other objects— seemingly an inexhaustible fount. Another strange thing was that no matter how much coffee was poured into the cup below, the liquid never over- flowed, nor rose above a certain height. The secret was this. Up the center of the down-pouring stream from the percolator spout ran a small copper tube, its upper end terminating well within the spout. The coffee was conducted from a concealed tank, up through the tube into the percolator and out again, this time on the outside of the conducting tube—the flow being sufficient to completely cover the 685 The mouth-breathing ap- paratus through which fresh air is supplied to a diver Pumping Air to a Diver Through a Bicycle Pump SIMPLE plan which boatmen along the Seine use to supply air to divers, in- volves the use of a bicycle pump, the hose of which is connected with a breathing device fastened over the diver’s mouth. The person on shore pumps the air at a given rate and the diver is enabled to stay under water as long as is necessary to complete his work, without returning to the surface on account of a diminishing air- supply. The device is composed of an elastic band which fastens pipe. The natural deep brown of the coffee harmonized with the coppery hue of the tube. The cup never ran over for the simple reason that a drain pipe at the KCONCEALED INNER TUBE bottom took care of the rCoreeE constant inflow. The Sk cup into which the per- Ajcano - colator poured stood Se upon a small tabouret SCHA whose legs were of suffi- PENTS CHER cient width to conceal gd the two tubes—the sup- LEVEL fo ply pipe and the drain. di An ordinary steel drill [7 Ftoor* eS) around the head, hold- ing the tube in place and making a water- tight covering over the mouth. The tube ter- minates in a mouth- piece which is held be- tween the teeth. This mouthpiece is a minia- ture air reservoir, through which the in- coming fresh air is passed to the air pas- sages at the back of the throat, and the used air is expelled through an exit pipe. ——S | t FINISHED AMMETER FRONT PAINTED BLACK The casing and works of a discarded alarm clock used for making an especially delicate hot wire ammeter to leave a slack in the silk thread. This is taken up by the tension of the spring, and causes the axle to wind up, making the pointer move along the scale. When the current stops flowing through C and D the hot wire shortens it up and the pointer returns to zero. The hot wire ammeter will make a useful addition to any wireless station, and is particularly handy for tuning. The success of the instrument depends largely on the care taken in its” construction, for although simple it is delicate and requires more accuracy in Popular Science Monthly making than the ordinary and cruder apparatus.—EDWIN JASPERS. Interesting and Instructive Electrical Experiments HE accompanying diagrams illustrate three interesting electrical experi- ments that may be made with the regular 11o-volt lighting current at practically no expense whatever. The first demonstrates LEAD : BI 110 VOLTS A.C. I a COMMON SALT’ SODIUM PHOSPHATE Experiment with salt water and phosphate - solutions for a rectifier and polarity indicator the electrolytic rectifier. Procure a strip of lead and one of aluminum about 1 in. wide and 3 or 4in. long. Tack these to a piece of wood so that they can be suspended in an ordinary drinking glass as indicated. This is the rectifier. Fill the glass about three- fourths full of water and add about a spoonful of sodium phosphate. Another glass should be provided and filled with ordinary salt solution. Two metal strips should be arranged in this glass the same as in the other, except that both must be of the same metal—copper, tin or whatever is most convenient. Con- nect up as shown with a I10-volt alternat- ing current, placing a 16-candlepower lamp in the circuit. be seen rising from one of the strips in the salt solution, thus indicating the negative pole. Temporarily short-circuit the recti- fier, and the difference between the two strips in the salt solution will immediately disappear as the current becomes alternat- ing again. If a small galvanometer is at hand place it in circuit.and it will be seen that when the rectifier is in circuit the needle is deflected, thus indicating a current in one direction only. Short- circuit the rectifier and no deflection occurs, although more current is flowing, as indicated by the increased brightness of the lamp. If no galvanometer is available, wrap some fine magnet wire around a — compass and the same result will secured. It is a property of the electric current to carry liquids along with it in its passage through membranes. This property is Immediately bubbles will 789 made use of in electrotherapeutics where certain medicaments are made to penetrate the tissues by placing them in contact with the skin and passing a current through the liquid into the body. This phenomenon t may be readily dis- i ponrt _ played by the simple / apparatus illustrated. gj 455 Procure two blocks of Tube 4 bepriss wood about I in. thick and 2 in. square. YjTYNIN WA INN AN WN Hollow out the cen- ters as indicated and — bore a hole at each corner so that they may be clamped to- gether with screws. Get two lengths of 3/16-in. glass tubing 3 or 4 in. long, and tightly insert these in the blocks as shown. Also run in the tip of a wire at the center of each block, after which shellac the spaces hollowed out in order that they may with- stand the liquid and avoid leaking. Place a sheet of thin leather between the blocks and clamp together. With an eye-dropper fill the interior through the tubes with a solution of common salt. Stop when the level rises in the tubes so that it is plainly visible above the wood. Now connect the two inserted wires with a direct current, and almost at once the level of the liquid in one of the tubes will begin to rise rapidly. Reverse the current and the liquid will rise in the other tube. If 110-volt direct cur- rent is available use it in series with a large lamp, or several lamps in multiple. If only alternating current is available, place the small rectifier just described in the circuit and the result will be the same. It is certainly mystifying at first glance to iI 110 VOLTS Experiment with a salt water solution to illustrate the idea of difference of potential Liquids are carried with electric currents dip the tip of a wire into the center of a jar of salty water and see two lamps light up while a very small one remains dark, only to light up when the wire is moved a little off center—either way—without any change having been made in the connections. The 790 accompanying diagram will illustrate how this may be done. The large lamps are ordinary 110-volt bulbs, while the small one is a battery lamp of 6 to 10 volts. This experiment well illustrates the idea of difference of potential. When the tip of the wire is exactly in the center of the jar, the circuit is “‘balanced’’ and no current flows in the circuit of the small lamp. This differential method of control has one marked advantage over the rheostat in experimental work in that it is possible to start with absolute zero.—JoHN D. ADAms. A Homemade Floor Push Button for Annunciators SIMPLE method of making an ordi- nary push button serve as a floor button for summoning the maid from the kitchen to the dining-room is Y/ shown in the il- wae lustration. Such a push has been in use for several years and is still in commission. The button was connected with the door bell sys- tem in such a manner that all the wiring neces- sary was across the small space from the button in the floor to the regular line. The button A was placed in a small bracket nailed to the adjoining joist D and a hole bored through the floor C. A short stick—a lead pencil will do—was passed through the hole and allowed to*rest on the button, as at B. The wires E lead to the bell circuit. A prearranged signal dif- ferentiates between a call from the front door and one from the dining-room or kitchen.—PuiLtie MvYErs. Push button on joist with floor connection Imitating Hard Rubber with Fiber as a Base HERE are numbers of wireless ama- teurs and electrical experimenters who are desirous of using hard rubber panels and bases, but who are unable to pay the almost prohibitive prices. Ordinarily, fiber cannot be substituted, for it has a tendency to warp and is very dull in finish. If, how- Popular Science Monthly ever, the instructions as given are care- fully followed out the resulting piece of fiber will be so nearly like hard rubber that it will take a close examination to detect the difference. The first operation is in smoothing down the rough surface with a piece of No. 1 sandpaper. When it feels smooth to the touch, continue with No. 00 emery paper until it shines in spots, then wipe with a cloth and finish with a cleaning compound, such as is used in kitchens, smoothing lengthwise only in long strokes. Continue this until it shines all over. For the second operation wipe all the dust off with a clean cloth, and then with another cloth apply a coating of hard wax, such as is used on furniture and floors. The wax should be slightly colored with an aniline black. Allow the wax to harden for about 30 minutes and then polish with a brush, finishing with a soft flannel cloth. Apply two coats as described, not less than 6 hours apart. A perfect finish will be the result. As the wax is waterproof and not affected by any ordinary temperature, the fiber will not warp. This has been used with perfect success on a panel 25 in. long and 15 in. wide in a somewhat pretentious mahogany cabinet.—R. G. YOUNG. Using a Well for a Wireless Ground Connection HEN a well is used for a wireless ground connection, the ground wire should be fastened to the top of an iron pipe leading to the bottom of the well by solder or by using a ground clamp. The pipe should be carefully scraped before the clamp is put in place. If it is desired to make connection directly with the water, brass and copper wire must be avoided because they have a bad effect upon the water. Often a well-ground of this sort will improve the range of an _ isolated station.—OTtTo KLATrT. Holding the Telephones Tightly Against the Ears COIL of wire or a brass spring slipped on the cord to the wireless telephones will hold them firmly against the ears. When in use the spring or coil is slipped up over the leads and brought up under the chin. This not only holds the telephones in place, but also eliminates trouble from noise of wind, passing wagons and the like.—G. P. Komp, Jr. 2 oy Popular Science Monthly Armature Winding for Small Series Motors N large generators and motors, the armature coils are wound and shaped on a form. This method is applicable to we FI6.2 Measuring the length of an armature coil with wire solder, and the pattern for the form - any slotted core. Consider in detail the winding of small series motors such as are used to run vibrators, massage outfits and small grinders. These motors are usually very small and a higher degree of heating must be allowed than in larger machines. The resistance of the motor must be high to prevent too much current flowing through and dangerously overheating its windings. These little motors are too small and inefficient to generate much counter force, so high internal resistance is a necessary feature. The current through the motor is only about .1 ampere. With so small a current as this the motors heat ‘too much to run for long periods at a stretch. Also, the radiation of heat from the windings is very poor, due to the large percentage of cotton insulation in small wire windings. The wire is very fine in the motor—about No. 32 double-cotton- covered on the fields and as fine as No. 36 d.c.c. on the armature. As these motors are bi-polar, the arma- ture coils go through slots 180 deg. apart. Commutators usually have at least 12 segments, so as to keep the pressure across adjacent commutator bars below to volts. Some have more bars. With high voltage between bars, sparking will be bad and 791 metal particles will easily cause adjacent bars to short-circuit. For example, in winding a 14-slot core that has a 14-bar commutator, there will be 14 coils and the size of wire will be No. 36 d.c.c. Before the form is made we must get an idea of the shape and size to make the coils. Remember that an arma- ture winding is symmetrical; that is, the coils are just alike, having the same shape, the same position in the slots and the terminals all coming out similarly. One side of a coil is put in the bottom of its slot and the other side of the coil goes in the top of the slot on the opposite side of the core. Now with a piece of wire-solder or lamp-cord you can make a pattern of the coil and see how it will work when done. See Fig. 1. Measure the length of the top and bottom sides of the coil. Say the top is 2in. and the bottomis14%in. Now take the pattern out of the slots, pull it out straight and measure it. Say it measures 7% in. Deducting 3% in. for the two sides, there is left 2 in. each for the two ends of the coil. Now make a form with these figures for its dimensions. A piece of thin board \ in. thick will do. Cut out the side pieces for the center form and. screw all three together. See Fig. 2 and 3. This can be mounted in a lathe or anything else you have with which to turn it. To determine the number of turns per Placing insulating material in slots, insert- ing the coils, covering and setting the brushes coil, cut short lengths of the wire and crowd the slot as full as you can, with say 720. Take 2% of that, or 480, as the proper 792 number to fill a slot. As one side of a coil fills but half of the slot, 240 turns per coil will be the requirement. Now wind 14 such coils, all-alike and in the same direc- tion. Use good wire. Never use a spliced or jointed piece of wire to make up a coil. Make a loop at the beginning of each coil before taking it off the form, so when the SG SRN Yj Z Z Z Z Z J q Y; Y; Z Z Z Z Y, Z 4 YA FI6.6 RN The winding and the commutator as they would appear if laid out on a straight plane time comes to connect with the commutator, the inner and outer ends can be dis- tinguished. It is best to tie a turn of thread around the ends of the coils so they will not unwind or fall apart. Now cut 14 pieces of Empire cloth and slip one in each slot, as in Fig. 4. Cut the cloth so it will project 4g in. past each end; the extra cloth sticking out on top will come in useful later. Now place the coils. Since the bundle of wir€ making up a coil is too thick to pass through the slot open- ing, the wires must be put in a few at a time until they are all in the slot. Squeeze them down to the bottom. Use no sharp tools to do the work. All the short sides of all the coils are successively put in place first. Always lay or place a given coil over and not under the one before. It is needless to say that the end of the coil with the terminals should face the commu- tator. The placing of the coils is shown in Fig. 5. With all the coils half in, it is now well to connect them together. Start with any beginning wire of a coil and twist it to- gether with the end of the coil occupying an adjacent slot. Keep on going around the core in the same direction. You will see that every coil on the core is in series with the one next to it. This is where our drum winding appears similar to a Gramme winding. Now tie a string around the whole core and coils and tighten it. Put your finger on any slot, and count slots in the direction the other side of your coil Popular Science Monthly goes till you come to number 8. The slot your finger was on at the start counts as number one, so the coil will occupy slots I and 8. If the coil does not seem to reach, keep on working all the coils toward their slots until they come down to shape. When all the coils are in, cut the extra Empire cloth off on top till only about % in. remains. Now, with the back edge of a knife, press these projecting edges of cloth in under the edges of the slot, as shown in Fig. 6. Then a fiber or thin wooden wedge can be driven in the top of the wire. After this, leave the whole armature in insulating varnish, enamel or shellac for a few hours, and bake the armature dry in a moderately heated oven. When dry, scrape all enamel from the commutator and shaft. Now determine where the leads from the coils go to the commutator. If the brushes are placed midway between poles, have the lead come from a coil to such a bar that when the brush touches that bar the coil is out of the field, or in the gap between the field poles, as in Fig. 7. This is easy and all the rest of the leads follow successively. When you have them all soldered to the segments, the job is completed. The winding just described is depicted in Fig. 8. This method of form winding has an advantage over hand winding, be- cause on small 110-volt motors there are so many turns per coil that hand winding would be exceedingly slow and tedious. In the case of the commutator having twice as many segments as core-slots, bring out loops from the coils when half wound. These terminals are joined to the alternate bars. It is simply a scheme to have a larger number of bars, and thereby cut down the voltage across each bar. If you have a 12-slot core and 6-segment. commutator, you can make a coil occupy a whole slot or else connect two coils in series before any lead goes to the com- mutator.—GEORGE STURLEY. Calibrating the Receiver for a Wireless Set ROUGH, but very useful wavelength calibration of a receiving set may be made as follows: Carefully tune the loose coupler to those stations using known wavelengths, being careful to select them so that the complete range of the receiver is covered, as 200, 300, eae © eee Tr a rr ‘lower left-hand corner. PRIMARY TURNS spsees 8 E58 SF 8 B Popular Science Monthly 7938 600, 1,000, 1,500, etc., meters. Make vertical line. In other words, a place final adjustments, using very loose coup- ling. If a series primary-condenser is in the circuit, leave it at the same setting for all stations. Make a note of the number of primary turns used for the best adjust- ment for each of the stations. On a sheet of cross-section paper, scale off the bottom in wavelengths the full range of the loose coupler, beginning at the Scale off the pri- mary turns at the left-hand side and from the lower left-hand corner. Plot the points at the intersection of the turns and the wavelength, and draw through them a fair curve, such as shown in the diagram. Al Ror | ¥ Z 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 WAVE LENGTH Plot the points at the intersection of the turns and the wavelength, and drawthecurve . If the points do not line up, see if the plotting has been done correctly; if so, the assumed wavelength is in error. Do not try to include the loading coil on the same curve, but make a separate one. Only the primary is mentioned, because the majority of amateurs use ‘‘untuned”’ secondary systems. But if this is not the case the secondary may be calibrated the same way, if a fixed loose coupling is used. The secondary shunt-condenser value must remain constant. A set so calibrated may be instantly adjusted for any station, even though it has not been heard before, pro- vided, of course, that its wave is known. The curve shown was drawn from results obtained according to the foregoing explan- ation, with a large loose coupler. Note that the line is straight at the shorter wave- length increases. If the loose coupler had been much larger, the curve would have reached a place where it would be nearly a would have been reached where a very large amount of inductance would have to be added to make a small increase in wave- length. With a larger antenna, this place would have been much farther out on the wavelength scale. Making Small Slots in the Frame of Pancake Helices N the construction of the pancake type of helices, the amateur is often puzzled over the method of sawing the slots in the frame of the helix in such a manner as to insure a snug fit of the brass or copper rib- bon used. In the construction of the primary of such helices, where the ribbon is usually about 11/16 in. thick, probably the best method of sawing the slots for the ribbon is to use an ordinary hack saw. The blade generally runs pretty close to the size of the ribbon, and this gives a snug fit, without the necessity of ‘‘shims’’—or small pieces of copper, brass, or wood fitted in the slots, which often result in a “‘messy’”’ job. In the secondary, however, the ribbon sometimes runs as small as gage 64. Saw blades of this size are very difficult to obtain, so the best way is to make your own blade. This can be easily done by securing a piece of an old clock-spring, which as a rule is very thin. Cut off a piece as long as your hack-saw blade, putting the two ends in a flame for a few seconds to draw the temper. A hole may then be bored in each end to fit the hack-saw frame. Draw the spring taut, taking care to hold it away from the face, as it will sometimes snap. Then press the “‘blade”’ against an emery- wheel till a series of ‘‘teeth’’ are notched in it. This does not make a very artistic looking job, but it will be found that it cuts into the frame—whether it be hard rubber or any of the finer woods—rapidly and with a clean stroke. Care should be taken to keep the blade cutting straight, as it will have a tendency to curve. If the right kind of clock-spring is used, a snug fit for the ribbon is assured. The pancake type of helix is probably the easiest for the amateur to make up, pro- vided he can secure the necessary ribbon. Although fiber or hard rubber is best for the frame, mahogany is very good, and is easily handled. On the primary, it is customary to space the ribbon )% in. be- tween turns, and on the secondary, where finer ribbon is used, 4 in.—PAut OArRD. 794 Making a Simple Relay Key for Wireless Operators HE arrangement in the diagram shows a simple and inexpensive method of constructing an efficient magnetic relay key to be used with an ordinary Morse key or automatic sender. An ordinary heavy key of the type used in wireless work is shown at An ordinary heavy key of the type used in wireless work with magnets A. It is connected in the primary circuit of the transmitting transformer by the terminals B in the usual manner. A pair of magnets obtained from an ordinary 4-ohm sounder is represented by M and fixed in the pcsition shown in any convenient manner. A sounder armature D is fastened to the base of the heavy key lever just beneath the knob, by means of a screw and washer. The magnet coils M are connected in series through their terminals £ with several dry or storage- cells and an ordinary Morse key. It will be readily seen that with this arrangement, manual operation of the light key will cause simultaneous operation of the heavy relay key automatically. By sub- stituting a vibroplex sender in place of the small key, perfectly satisfactory results may be obtained. Care must be taken to adjust correctly the spring tension on the key lever of the heavy key to secure the best results—NormMan A. Woopcock. A Multiple Key for Sending Wireless Messages Y mounting two key levers side by side on acommon base a high speed hand- operated trans- mitter in its sim- plest form is ob- tained. The keys should be con- nected in parallel. Adjust the spring ononesoastoraise the lever sharply for the dots, and the spring on the other. so as to work more slowly, for the dashes. Two easily built strap keys are suitable for the purpose. Two telegraph keys mounted for fast sending Popular Science Monthly Care is necessary in order to send good,, fast, clean-cut Morse in this way, but with: a little practice it can be done, and operat-' ing speed will gradually increase. Both: keys are of course manipulated with one hand.—Joun B. RakoskI. A Novel Crystal Support Made of Flashlight Globe = | the illustration, A represents the base’ of a miniature flashlight balb, all parts except the shell having been discarded. When this is half filled with solder’ the crystal is molded in. A set of minerals may thus be mounted to work in conjunc- tion with a miniature a porcelain base socket, B, which is fastened to the de- tector base. The mineral itself may be screwed into place and rotary adjust- ment of the mineral secured in the same manner. Contact is made from both binding posts of the base socket.—JOsEPH BRAFF. The lamp screw and the porcelain base A Multiple Electrode Rotary Spark-Gap T is a well known fact that there is a great deal of energy lost in heat at the electrodes of the spark-gap. This is par- Multiplying the electrodes will increase the efficiency of transmitting apparatus ticularly noticeable and very objectionable in a plain open gap. The rotary-gap over- comes the difficulty to a certain extent, on account of the cooling action of the wheel;. but most amateur rotary-gaps can be im- proved upon in this respect. An increase in radiation will be noticed in most cases if a number of electrodes are used in place of single stationary electrodes. The arrangement shown in the drawing is simple and will amply repay the careful builder.—W. A. Parks. a — Gl Ga bane, aH WE S S , ey ZS cS “lh é os = os Ff a0 7° te i ie OKaogr” a Ges The author of this article, Capt. A. P. Corcoran, has just returned from France, where he served with the British army. His military work included the installation of signaling apparatus. The following. contribution from his pen, therefore, will give our wireless readers some first-hand information on the war-time usage of radio apparatus.—EDITOR. is romantic in the performance of the quite definite. There is no scrap in which wireless man in warfare. He does _ he does not have his share, no division of not charge with bayonet fixed to rush an the army in which he does not have his. enemy trench. He does not kill or conquer. And the popular imagination 3 finds it hard to see a hero in a man whose duty is the mere recording of others’ exploits. Like the dispatch-rider, indeed, the wireless oper- ater is likely to become conspicuous only when he fails in the task assigned him. Then he has an op- portunity to judge his im- portance by the measure of the opprobrium poured on him. When he fails, of course, he never fails alone. Yet technical and un- heroic as his task may seem, it calls for gallantry equal to that of any. Not only does he share in all the risks run by the a ie the public at large there is little that The position of the wireless man is now Tommies, but he lacks all The first set yp range acouty on boned bas te —<— be- : came apparent that a different outfit was n and one SD eescighs lar eterdi cides more easily transported; hence the box set came into use side with them in the front line trench, place, whether it be infantry, artillery, air- ready to join in the attack, his sole weapon service or cavalry. That he is absolutely is his wireless apparatus. Hecarriesneither indispensable in achieving results has been rifle nor bayonet. conclusively proved in the battles along 795 796 the Somme by endless instances of dis- tinguished services rendered. In spite of his obscurity, he has won many decorations. But that his service is still far from perfect, however effective it has proved, was still evident when I left France less than a year ago. I do not intend to be technical in my explanations in this article, but, in order to make clear the experiment- ing that has been done in wireless in this war, it is necessary for me to go back to the beginning. My aim is to give a short history of the wireless in France—its de- velopment in brief outline. At the very outset of hostilities, before the trench warfare had begun and the armies had settled down to their present deadlock, the wireless was necessarily of a different character from that used now. Then a motor lorry set—a 1% K. W. Marconi set—was supplied to the Signal Branch of the Royal Engineers. All through the retreat from Mons and during the fight on the Marne, this set was used and did excellent work. But with the end of the moving fighting and the beginning of trench monotony, the lorry set lost its value. Soon it was entirely supplanted by the systematic working of trench telephones, and for a while the wire- less went almost completely out of use. But not for long. The ineffectiveness of trench telephones under certain conditions was soon very painfully apparent. When actual fighting was in progress, they failed more than once at critical moments. Some- times a shell would break down the com- munications; or an artillery battery would carry off the air line poles; or an enter- prising Tommy, on his way through a com- munication trench, would cut off a length of cable to make a shoe lace. Even commanding officers who were al- ways sceptical on the subject of wireless in the trenches, were forced to confess that their old friend, the telephone, was not always reliable in case of a crisis. So, on their recommendation, it was decided to undertake some experiments which would perfect the wireless for warfare. It was now decided that the requirements of the new fighting called for a portable set for the first line trenches, and a group of officers who had already distinguished themselves in various capacities, were de- tailed to take charge of the work and evolve an instrument for the purpose. They introduced a small, simple set con- sisting of a I-in. spark coil, Leyden jar Popular Science Monthly condenser (3) and an aerial coil. Receiving, a single inductance, silicon detector, vari- able capacity ’phone condenser and ’phones 1000 ohms. The aerial was supported on two 8-ft. bamboo poles, 80 ft. apart with a | single wire. The ground consisted of a wire — gauze mat 8 by 3 ft. With this set it was discovered that fairly loud signals could be heard from three to five miles. When the instrument, however, was put to its first real test at L , it rose magnifi- cently to the demands of the situation, acting to its full range of five miles. For a long time this set was used with excellent and unvarying results. In regard to the transmission of messages it lacked nothing. But it had just one drawback—a minor one but occasionally important. Being placed loosely on a board, it was clumsy to carry, a fact which often hindered. the work by causing loss of time. Once more the officers set to work. It was a Captain L who found the means | of combating the difficulty. He discarded the board, and substituted a box 18 by 9 by 9 in. in which he placed the set. This was carried on the back and proved to be a. most compact and convenient instrument. : I remember when the first experiments . were made with this set, some distance behind the line. They took the form of contests between the wireless and_ tele- phone. A detachment from each would start off from a trench, as if during an actual engagement, to a position some 500 | yd. distant. Then each would do his ut- most to establish communications as quick- ly as possible. From the very first the wireless man won ~ by an average of some thirty seconds, no. small consideration in warfare, when per- haps it is a question of holding ground already gained. é The instrument being now perfected, the. next question was the training of the men. In England depots were at once established, and young fellows already equipped with a working knowledge of the job, such as Post Office Telegraphers and the like, were en- rolled in the wireless section. Similar schools were established in France behind the lines at each of the Army Head- quarters, and the officers in charge would occasionally go into the trenches and pick out a few of the most intelligent infantry men with a view to training them as operators. No Tommy but tried his hard-- est to be picked. He looked on the training | as a good opportunity to rest, a nice break Popular Science Monthly ing of operators, there was also one for the officers, to which I myself was attached for some time in the capacity of lecturer. The wireless section is now, of course, one of the largest and most important factors in the Royal Engineers, but at that time it was comparatively unimportant, and there was naturally a shortage of officers fully trained in this branch of the work. Consequently to meet this deficit it was the custom to bring back signaling officers from their brigades for a short,. sharp course of two weeks. This, coupled with their previous knowledge of telegraphy and circuits, was found to be sufficient to make them efficient leaders. The operator naturally took longer, being absolutely untrained in such work, and his course usually lasted from three months to four or even more. The measure of his qualifications, however, was high and definitely fixed. He had to be able to send and receive at the rate of twenty-five words a minute, English, and twenty words a minute code and foreign languages. He had to be able to assemble and dismantle Marconi 114 K. W.; also to have a working knowledge of trench sets and a thorough knowledge of army procedure. As a matter of fact, he rarely needed to work to the full height of his ability, for, in actual warfare, he found that the nec- essary speed rarely exceeded from fifteen to twenty words a minute, according to the activity of the Boche gunners. The wireless, as I have said, is now an essential part in all trench warfare. When the infantry advances to an attack, the operator is always slightly in the rear. Where formerly a detachment of men had to reel out hundreds upon hundreds of yards of cable to establish telephone communica- Wireless stations along a line for six miles, the last one using an umbrella type aerial tion between a trench newly taken from the enemy and the first line reserve behind, now the operator simply picks up his box, his ground mat and his aerial single-handed and advances simultaneously with the at- tackers. Arriving at his new position, he props up his aerial, lays his ground mat, and communications are established almost at once. It would be hard to overestimate the importance of his duties. When an enemy trench is being taken, it is he who reports the progress of the encounter—the number of the enemy, the nature of their defence, the amount of the casualties on either side, the condition of the trench when it is finally taken—whether it has been badly damaged by artillery fire, or whether it is practically intact. If a gas attack is com- 798 ing, it is he who sends the warning to the men behind to put their gas helmets on. If the aeronaut can be called the eyes of the army, the wireless man is its ears. Naturally their work is made to dovetail. When one sees, the other hears and also reports. One of the main duties of an aviator, as you probably know, is to reconnoiter for the army, and to report on the accuracy of the artillery fire and on the location of the enemy batteries. But he does not have to descend to re- port his discoveries. For he, too, is equipped with a wireless set—a Wilson set is the one usually carried—with which he transmits his information to the man below. This man is stowed away always in a dug-out, at a little distance from the bat- tery. It is in accordance with the infor- mation he receives and transmits that the artillery fire is directed. Every branch of the army, as you see, has its own particular station, and its own particular duties to discharge. Back at Army Headquarters where the large station 144 K. W. Marconi is situated, the work of the wireless mainly consists in intercepting communications from the enemy and taking aircraft reports. But though each of these stations works separately, they are all in close touch at all times. For instance, every bat- talion carries two trench sets, each having two Popular Science Monthly operators. They are in the front line with the infantry. Back with the reserve, about one hundred yards behind, are two more sets and two more operators. Back still further is-a larger set at Brigade Head- quarters. At Divisional Headquarters is a 4 K. W. set, and at Army Headquarters isa 1% K. W. An attack is made. The battalion oper- ators go over slightly in the rear of the infantry. They communicate with the station in reserve, who in turn pass it on to Brigade Headquarters, who pass it along to Divisional Headquarters, who report it to Army Headquarters. A few have asked why this method of communication is adopted, and have sug- gested that it would be more effective if one large set were established close behind the line, to replace all these individual trench sets. Communication, they say, would then be direct with General Head- quarters, and much time might be saved. That was tried. I remember the occasion distinctly. The station was erected, the apparatus installed. This consisted of a motor lorry set, 1144 K.“W., 120-foot steel mast, an umbrella aerial, with a complement of three operators. It stood for just two hours. Then over came one of those huge 5.9 shells, and the lorry. set, the steel mast, the um- brella aerial and the three operators were all shot sky-high. I presume Back at Army Honckipar Gi, where the ele Marconi station is situated, the tet of the wireless consists mainly in intercepting communications from the enemy and taking aircraft reports - a a ha a tl —e ep “7 alee | i Pa Re ee te they have since then come down again. The result of this experiment, naturally, was an increased regard for the trench sets. But these were by no means perfect as yet. Of course, in addition to the latter, there are automobile sets, aero sets, wagon sets which are used for all moving fighting, and pack sets for the infrequently active cav- alry. But none of these has required the time and attention devoted to the instru- ment used by the infantry. As the aerials have to be erected over the trenches, the poles being stuck on the par- apet, they were naturally attractive targets. Naturally their operators came in for their share of the snipers’ shells. In this connection, I would like to tell the story of a friend of mine, Lieutenant L., which will bear out my contention that, when it comes to the scratch, a wireless man can be as cool as the next. He was adjusting one of the stays of his aerial pole which had been disturbed by the falling of a shell close by. As he was doing so, over came a second shell, known to the Tommies as a “whizz-bang,’’ which gave him a direct hit, tearing his arm clean away, except for a stump of 4 inches. He _ looked at it calmly for a couple of seconds. “Well, that’s a ticket for blighty,” he exclaimed then, and fainted. (Blighty, it might be explained, is a Hindustanee word for home which the Tommies have adapted for their own use from the vocabulary of the Indian troops.) It was such accidents as this, however, combined with the occasional collapse of the aerial, that convinced the authorities of the need for further experimenting. The officers were now given a more or less free hand to test ideas of their own. When I left France, many new devices had already been introduced. From what I hear, they have since been perfected. An Easy Way to Wind Sending Helices T IS often very troublesome to wind aluminum or copper wire into a circular form for helices or oscillation-transformers and make a neat job. The following method will be found very satisfactory for the amateur. Secure some old lumber 2 in. or more thick and with a compass lay off a circle or circles, which should be smaller in diameter than the diameter of the helix to be made. A good rule to follow is to make Popular Science Monthly 799 the diameter of the disk of wood about 2 in. less than the finished helix. Though the resulting coil may then be a little too ‘small, this may be easily corrected in assembling the instrument. Cut out the disks of wood with a scroll- saw and be sure they are perfectly round. Make a hole in the circumference of each disk just large enough to receive the wire. Bend the end of the wire at a right angle, insert the bent portion into the hole and fasten with a staple. Wind the wire on the drum the required number of turns and allow the wire to remain in this position for a short time, when it may be removed and used. A disk of cardboard cut to the correct size, may be used as a gage to determine whether the helix is kept the right size while assembling. Improving the Wireless Aeroplane Set HE past year will go down in radio history for the memorable advances which were made in radio communication from aeroplanes—an advance directly traceable to the European war. The lessons taught by the great conflict were not lost upon our Navy Department. As a result, more official encouragement has been given to manufacturers and developers of wireless apparatus in this country than ever before. At the end of 1916, the Navy Department issued - requisitions for fifty aeroplane sets. This was the result. of three different tests. So successful were the tests that the Navy Department felt itself justified in placing an order for fifty sets at the end of December 1916. From the Marconi Company sixteen sets were ordered to be operated on the 500- cycle, quenched spark principle. Nine- teen sets of the audion type were ordered from the De Forest Company. Thirteen Dubilier sets, using the direct current quenched arc, were ordered from the Sperry Gyroscope Company. The awards were sufficiently generous to encourage the manufacturers, amounting as they did to about $60,000 altogether. Thanks to the Navy’s interest in wireless, we are now far in advance of any European nation in the art of communicating by radio from aeroplanes. We can send twice as far as any other country from the air. It is interesting to note the characteristics of the successful sets. The Marconi Com- 800 pany submitted a 1-kilowatt set complete which weighed 100 Ib. Each of the De Forest audion sets weighed 86 lb. The Dubilier quenched arc set weighed 64 Ib.- The three sets in question were given rigid scientific tests, each manufacturer having seen to it that his apparatus was abso- lutely foolproof. Mr. Dubilier’s system is particularly interesting. Formerly Leyden jars were broken and short-circuited. The entire set was out of commission until the broken jars could be renewed. Hence, warships, as well as airships, were in danger when the Leyden jars gave out. In the Dubilier system, the secondary is not short-circuited, whatever happens, but continues to work uninterruptedly. Hence, it is practically impossible to throw the set out of order. How to Make a Sending Oscillation- Transformer for Wireless HE construction of the oscillation-helix 3 is shown in the illustration. . The heads of the primary or larger coil, are 7 TURNS NO 8 ALUMINUM WIRE *% ji ° ’ \ Ay, % \ i \ ~~ UT = if Fae fa fal A sending oscillation-transformer that will prove. valuable to any wireless station 1 in. thick and 12 in. in diameter, and are held apart by four strips of wood 9 in. wide and % in. thick, which are placed in %-in. notches in the disks as shown. This makes the distance between the two heads 8 in. The lower head is provided with three legs, which may be made of fiber. Insulators screwed to the bottom of the head will answer the same purpose. A 1I-in. hole is drilled in the center of each head to admit a 15/16-in. dowel or a piece of curtain pole of the same diameter and 26 in. long. Several slots 4%4-in. deep are sawed near Popular Science Monthly the top of this vertical rod. A small strip of brass is made to fit into any one of these slots, the purpose being to hold the secon- dary in place after the proper coupling between the primary and secondary has been determined. When all of the parts of the primary have been assembled, it is wound with 7 turns of No. 4 aluminum wire as shown. secondary, or smaller coil is next made, the heads being 8 in. in diameter with a 6-in. space between them. It has four uprights which are notched into the upper and lower heads in the same way as in making the primary. The heads of the secondary are drilled centrally to admit the dowel. When the secondary has been assembled it is wound with 11 turns of No. 8 aluminum wire. The strip A, which holds the secon- dary in position, is made from a piece of 1/16 in. copper or brass 24% in. long and 1 in. wide. One end of the strip is drilled for a small handle while the other end is drilled to admit a screw that holds the vided on top of the secondary. The oscillation-transformer will be a valuable addition to any wireless station and will help comply with the wireless law regarding pure waves andwavelengths. It can be used with a transformer up to and including 1 K. W. input, and has just the right amount of inductance in the open and closed circuit sides to permit a range of periods well above and below 200 meters. Testing the Sensitivity of the Telephone Receiver A VERY simple experiment illustrating the extreme sensitivity of the ordinary telephone receiver may be made as follows: Connect each terminal with about 2 ft. of magnet wire of small enough gage to be easily handled. Connect the free end of one wire to a small scrap of clean sheet zinc. Then while the receiver is held to the ear with the left hand, moisten the end of the other wire on the tongue and touch it to the scrap of zinc. Immediately a definite click will be heard in the receiver, thus register- ing the infinitesimal current generated by this minute galvanic battery. Most amateurs fail to appreciate the value of the watch-case receiver in testing for leaks and short-circuits, and accordingly resort to magnetos or galvanometers which are not nearly so sensitive, as a rule. If you have a galvanometer subject it to the above test.—JoHN D. ADAms. The © te a el a ee ed en) ee Of all the magazine readers in America, probably no group would show so high a percentage of efficiency as the PopuLar SciENcE Montuty family from the standpoint of our Country’s need in the present crisis. 7 In the first place, a very large proportion of our many thousands of readers are young men—vigor- ous, intelligent, alert. In the next place many—very many of our readers follow vocations which, from the economic stand- point, are vitally important to the Country’s pro- gram of preparedness and conservation. In the third place, where could you find so im- pressive a number of men—and women too—with the inventive type of mind? Who can tell what will be evolved from the experiments and discov- eries of PopuLAR SCIENCE MONTHLY readers and how far-reaching the benefits thereof to our Country? We must, one and all, in whatever direction the path of duty lies, give the best that is in us, placing patriotism above selfish gain; self denial above personal indulgence. Our Country is a land of liberty and opportunity. Let us search our hearts and our brains for those qualities whereby each one of us can best do his share towards preserving and upholding these price- less attributes. Mere Firing of Guns Is Child’s Play to This! TSS The cable is strung over small tr protection is available. If the about six miles an hour; but th ees or hedges wherever possible and is buried when no other men are not killed they accomplish their task at the rate of € enemy artillery find the cable detachment an excellent target 802 Popular Science Monthly 239 Fourth Avenue, New York City Vol. 90 No. 6 June, 1917 $1.50 Annually Laying Telegraph Cables Under Fire How the British lay communication tele- graphs in the field and in the trenches By Captain A. P. Corcoran, late of the British Army Readers of the POPULAR SCIENCE MONTHLY are by this time familiar with the name of Captain Corcoran. He has iately returned from the front where he saw the service that he here describes. He is the author of the article “Wireless in the Trenches” that appeared in last month’s issue of the POPULAR SCIENCE MONTHLY.—Editor. ITHOUT communication, of course, VW\ war could not be waged. For a while the electric flash lamp was used. It took the form of a small, four- volt bulb, placed in the barrel of a rifle. The rifle was sighted directly at the re- ceiver, who was the only person in a posi- tion to see it. But this method of communi- cation was too slow. Now the wireless, the telephone and telegraphing buzzer are used. From General Headquarters up to Bri- gade Headquarters, the method of connect- ing up these instruments is by air-line. But from Brigade Headquarters up to Battalion Headquarters and all along the line of the trenches, cable has to be used. A cable detachment consists of ten men, eight horses (four riders and four draft) and a wagon, the leader and the near wagon horse having drivers mounted. The wagon carries a number of poles for bridging crossings, and four drums of cable, each con- taining five miles of No. 14 insulated copper wire. The inside end of each drum is con- nected with the wagon and contact is made with a telephone on the box seat. Suppose the cable is to be laid between points A and B. The loose end is paid out and man No. 8 (Nos. 9 and Io being mounted on the draft horses) connects it with a telephone and remains at point A while the wagon moves off at a trot. Man No. 1 now rides on ahead, to pick out the most suitable course to travel. Man No. 2 works the telephone on the wagon, constantly keeping in touch with point A. Man No. 3 sits in the wagon, easing the cable off the drum _ Nos. 4 and © Int. Film Serv. A telephone corps of the Fourth Division of Royal Engineers (British) picking up a mes- sage through a wagon telephone equipment A switchboard in a crude dug-out with makeshift appliances, which rivals the most modern New-York-to-Chicago line in efficiency 803 804 5 likewise sit in the wagon, armed with mathook and spade, ready at. any moment they come to a crossing to jump down and dig a small trench. This is usually four inches deep, the object, of course, being to bury the cable out of danger from passing vehicles or horse hoofs that might cut it. Having concealed it, the men tie each end Popular Science Monthly This pack consists of four men. No. 1, whose duty is to pay off the cable, carries his equipment strapped to his back. The cable is done up in a reel, consisting of about 2,000 yards of 18-gage, a smaller one than that used in the wagon set. No. 2 leads the way, fixing little wooden pegs in the sides of the trenches. No. 1, to some standing object close to the trench, so that the cable will not be pulled out of its grave. That opera- tion completed—it usually takes three or four minutes— the wagon again moves on. Now behind the wagon there follow always two riders— Nos. 6 and 7, each armed with a crook stick. This consists of a piece of broom handle, fitted at the end with an iron hook, and is used to lift the cable on the tops of hedges or small trees or other objects which might help to keep it off the ground. Witha lift of the arm, No. 6 swings the cable on high; but, should he chance to miss any of it, No. 7 does his work. Should the wagon of course, follows on behind, paying out his cable as he goes. Nos. 3 and 4 follow No. 1, their duty be- ing to tie the cable to the wooden pegs affixed by No. 2. In the trenches, naturally, there is always the danger that the cable may be cut through by shell fire. Various devices have been introduced to lessen this danger. The method of laying cable in loops, one of which will always ‘preserve the con- tact, though the others be cut through, has been found most effec- tive in actual fight- ing. Technical and safe as all these tasks sound, they are nevertheless at- tended by their own difficulties and dan- gers. When the come to a very large crossing or perhaps a brook, the cable is nt. Film Serv. British signal officer receiving communica- tions, while he keeps his eye on the enemy enemy artillery and airplane scouts are busy, they find a not buried but borne overhead. In this case it becomes the duty of Nos. 6 and 7 to ride up to the assistance of Nos. 4 and 5. Between them they erect two poles, each eighteen feet high, one on either side of the crossing—an operation which takes five or six minutes at least, as the holes have to be jumped for the poles. The cables are laid at the rate of about six miles an hour. In the trenches, of course, the method is entirely different. Since horses and wag- ons are not practicable, what is known as a ‘‘man pack”’ takes their place. cable wagon an excellent target. For instance, during the retreat from Mons, a cable wagon was sent out to re- establish communication between units severed during the retirement of the troops. Overhead circled a German air- plane in search of prey. It got the first wagon. Another wagon was sent out. The airplane got it, too. Then a third essayed the task. And this one, all of whose men expected, of course, to be blown sky-high, succeeded, where the others had failed. Such is the luck of battle. To my mind there is something pecu- aes A aad . Popular Science Monthly liarly romantic about the work of these telephone and telegraph men in France. To begin with, they are extraordinarily efficient. Suppose you want to get a mes- sage through from some tiny unit at Ypres to another equally insignificant at Albert—a distance of some one hundred miles. They will do it for you in less than four minutes. In New York or Chicago, with all modern appliances, with up-to-date, comfortable quarters, you could not obtain an equivalent con- nection in less time than that. It may be romantic todo battle. Battle rouses your blood, and the instinct of self-preservation will always help you in a fight. No disparagement of the fighters— but I take my hat off to the man who can do a cable-laying job under fire. Another Inventor’s Idea for Speeding Up the Automobile OME patents suggest mainly the idea that somebody somehow is making a little money out of somebody by getting the patents issued. Until September 19, 1916, we could all, for example, freely mount two 42-inch, 8-bladed propeller-screws in front of our motor-cars and connect them with the hubs of the rear wheels by means of six pairs of bevel gears, two long rods and two universal joints; but on that date Edward Wintermute of Exeter, Nebraska, had such an arrangement re- served for himself alone and those on whom he may see fit to confer the same privi- lege. The illustra- tion shows one of the ways in which this conception can be presented by pen and ink without challenging the appoint- ment of a com- mission in lunacy. PROPELLERS The propeller-screws in front of the car are intended to increase its hill-climbing ability seventy-five per cent Gustave manicuring the nails of the employees of the dining-room, kitchen and pantry of a New York hotel with as much care as if they were patrons New York Restaurant Waiters and Cooks Must Now Be Manicured MONG the many innovations which the age has produced, none seems more novel or extreme than one of the regu- lations in reference to health and hygiene recently introduced by the management of a great New York hotel. Under the new rules, an official manicure has been installed to take care of the hands of the cooks and waiters. Every day each employee who is in any way connected with the serving of food must report to the official manicure to have his hands #P thoroughly scrubbed in hot : water and his nails cleaned and polished. The mani- cure is. per- haps the busi- est of the ho- tel employees. When his first dutiesareover, his task of in- spection be- gins. At no time of theday or evening is a careless waiter or cook safe from his scru- tiny. ott LER i LEVER AIR BRAKE The applicant stands on a platform close to the motion-picture screen with the con- troller and air-brake handles in his hands. He is supposed to operate them just as he would if he were on a car on the street The controller and brake levers are con- nected with a tape recording machine. Moving the handles causes two needles to trace lines or curves on the tape. At right are the examiners watching the tape ¥ eee ee ‘ £ 3 * ome ‘ee ao a al ~~ ~~ a ‘eo Cd - Testing the Motorman’s Quickness and Skill The speeding automobile, the busy street and the excited crowds are brought into the testing room—on the screen school for motormen, which is main- tained by one of the street railway companies. of that city, has devised a test for ascertaining the efficiency of motormen by means of a motion picture screen and a clockwork tape-printing mechanism. The test, in some respects, is similar to that which is used in determining the re- liability of French war aviators which was described in the October number of the PopULAR SCIENCE MONTHLY. In the test for French aviators, the candi- date’s quickness in responding to certain sensations, such as sound, sight, and feel- ing, was carefully recorded. The quickness and accuracy of judgment of a motorman at the controlling handle of a street car traveling at high speed when an automobile darts around the corner and down the track would determine his fitness for the job. hes instructor in charge of a Brooklyn The accompanying drawing shows the arrangement of the testing apparatus. On the platform before the motorman- applicant is mounted a _ regulation-sized street car controller and air-brake lever. Half-way down the room facing him is a moving picture screen. Back of the screen, at the other end of the room, is the pro- jection machine. The controller and brake levers are connected electrically with a tape- recording machine. The tape is about three inches broad and is marked by two self-inking pens. Moving the handle of the controller or the handle of the air-brake causes two needles to move, tracing irregular lines, or curves, along the tape. As soon as the picture is flashed on the screen, the applicant is ordered to operate the two handles as if he were actually on the platform of a street car. The pic- ture, taken from the platform of a moving — car, shows an assortment of contingencies. 806 a Popular Science Monthly Beach Patrol of the Coast Guard HE efficient beach-patrol system maintained by the United States Coast Guard for the protection of mariners was originated in the early ’seventies by what was then known as the Life Saving Service. It is in op- eration by-night, from sunset to sunrise, and also by day when the weather is thick or foggy. The crew at each Coast Guard station is divided into watches of two men each, who are charged with the duty of patroling a regular beat, laid out in each direction from the station along the shore, and varying in length, according to the conformation of the coast, from one-half to four miles. The patrolman is expected to keep a sharp look- out to seaward. While the patrolman is out on his beat, his watch-mate takes the station watch, which is kept in the tower or on the beach abreast of the station. Besides No two of the stones in this house are alike. gathered from all parts of the world and each has a history They were A ‘Crazy Patch’’ House Built of Stones from Everywhere HE “crazy patch” house of David F. Brown, in Punxsutawney, Pennsyl- vania, is composed of stones from all parts of the world. There are stones from every State in the United States, stones from Italy, Ireland, China, Japan, South America and other places innumerable. Grind- stones, millstones, keeping a watch sea- ward, the station man is on the look- out for signals from the patrolman. When the latter, ‘having covered the beat in one direc- tion, returns to the station, he takes the station watch, and his mate patrols in the other direction. In harbors and sea- ports, fixed lookouts are usually main- tained instead of a beach patrol. Every patrolman carries a supply of red Coston signals, with which to give warning to vessels standing too close inshore, or to notify a vessel in distress that he has gone to stones from the Mammoth Cave, from Pike’s Peak, from the home of Patrick Henry, from the spot on which General Lee surren- dered and from every historically famous place in this country, go to make up the ‘‘crazy patch”’ house. Over the fireplace is a piece of gold quartz from South America. It required two years to build the house, but Mr. Brown and his friends and relatives knew of his who hobby for collecting odd stones, spent much more time than that getting the necessary number of summon the neces- Sary assistance. The patrolman keeps a sharp lookout to sea- ward while his watch-mate guards the station stones of which no two were alike. Rudyard Kipling’s “ Bloomin’ Idol Made o’ Photos © Newman Traveltalks and Brown & Dawson The original religion of Japan is a mixture of nature-worship with ancestor-worship, but Bud- dhism hasa strong hold too. Above is shown the thirty-three stone Buddhas of Nikko, splotch- ed over with paper prayers pasted on by pilgrims In China, Confucianism is the principal religion. It is a moral system which refuses recognition of the unknown and emphasizes the duties and joys _Of the present and especially of the home and family. At left is the God of Happiness, of Canton pn ee One of the chief characteristics of the Hindu The finest “Buddha” statue in the world is at faith is the acceptance of the cow as a sacred Kamakura, India. It is of bronze and is animal. Above is the Golden Bull, of nearly fifty feet high. The forehead pendant Benares, India, which is greatly reverenced is of silver and weighs nearly thirty pounds 808 Mud—Wod They Called the Great God Budd—” = ao Photos @ Newman Traveltalks and Brown & Dawson & m2 a - Aad ™ ~_ an r $ a =< = India boasts of nine specific religions and almost innumerable gods. Above is the terrible God of Thunder and Lightning with his thunder-bolts in hand. The image is made of bronze with ivory teeth and horns. Glowing rubies represent the eyes. During the hot, dry season, which begins in March, the Hindus besin making sacrifices to this fiend-god so that when the rain dces come it may not do more harm’ chan good, as is sometimes the case in this land of climatic extremes In a niche in the entrance hall of the Temple of Iyeasu, Japan, is the exquisitely carved golden demon-dog Wo, which is shown in the photograph above. Itis a terror to thieves 809 Usually the gods and goddesses of plenty carry fruits and vegetables in their hands, but this Chinese god measures abundance in jewels and gold in a very occidental manner A New Art—Dried Apple Sculpture Miss Isabel Mi€illion, of Knox- ville, Tenn., reproducing her ‘‘Po’ white’? mountain acquaintances from dried apples. How she pre- vents the apples from _ wither- ing further after she has carved them is Miss Million’s own secret Photos © Press Illus. Serv. A faithful por- Gs trait of Harbe Hawkes and his “ole woman.’’ He raises ‘“‘ta- Ze ters’? while she Pas patches quilts. Both are a little rheumatic, but . ° ae otherwise ‘‘mid’- ‘Tine so 9 ” ; eee lin’, thank ye y ee th. f eee? me a g 202? Chae ‘ a. eee Paes eae a A-type often se seolre With in th 3 Sitees met Wit | in e Se eae ee mountains of saceeeee : the South. She paceeee Sepees ¥ta makes rag car- Stietesecics: | t @ pets and lye Se eeaeee + * * et % ye soap for a living Len eeere ciate and is saving to buy aset of store teeth—a won- derful luxury 810 Tobe Lemons of Smokey Cove has a misery in his: “chisé- which prevents him from mak- ing an honest living. He is just strong enough to ped- dle whiskey It is wonderful the amount of expression and the detailed his- tory which these little figures re- veal. Here is the village seam- stress going to churchdressedin “Sunday” clothes Eluding the Customs Inspectors of Paris Below: Customs inspectors were attracted to a lawyer who car- tied his portfolio under his arm instead of by the handle. It was found to contain a bookshaped vessel filled with dutiable liquor This man looked like a prosper- ous merchant of generous pro- portions; but the inspectors soon found that he wore a whiskey- filled cylinder under his coat A funeral wreath made over a hol- low cylinder. None but the most cold- blooded would suspect it as a carrier of liquor The convenience of a tubular horse col- lar could never be overlooked by the liquor smugglers Sil Above: A roll of goods with a hidden compartment in which liquor or other dutiable commodities may be hidden. Trucks loaded with such rolls are often seized The face of the woman above was too youthful for her waist- line. It was found that she wore a rubber petticoat stocked with the most expensive liquors All Play and No Work Tends to Make the A sport for energetic youths. Keep your sitting position and stay in the chalked ring—if you can. The pushing is done with the feet alone and only rubber and canvas shoes can be worn Riding turtles af- fords an exciting mo- ment or two. The turtles don’t mind it and the riders think it great sport. The turtles will be served up later for soup Photos © Brown and Dawson The bottle race is the grown-up’s “‘play horse”? game. The men are blindfolded and the women drive them in and out among the lined-up bottles which are spaced about two feet apart. The champion bottle-dodging team is the one which fails to knock down a bottle 812 Voyage Take On a Carnival Appearance Shuffleboard is the aristocrat’s game. The aim is to shove wooden disks with a cue into the divisions marked off on the deck. It has been called salt water golf lookers like—the cock fight. One man has a pillow with which hebe- labors the other and triesto break his partner’s hold of the pole without losing his own balance Photos © Brown and Dawsoa The potato race is the child’s delight and the old maid’ one by one and deposited in the dish or receptacle at th the potatoes in her line to the dish in the shortest time i 813 e end of the line. s Waterloo. The potatoes are picked up The one who carries all s the winner. The captain keeps the score “Preparedness” Includes Women Wireless Operators VIN The code room of the Girls’ Wireless School at Hunter College, New York. The students are instructed and drilled in every branch of wireless work Photos © Underwood and Underwood Miss Marga- ret M. “A, Donahue, of Boston, Mass., the very first woman in the United States to receive a first- class license for commercial radio operation The laboratory at the wireless school at Hunter College. The apparatus and appliances are up- to-the-minute and complete in every detail. The girls have offered their services to the Government 814 Training Four-Footed Red Cross Recruits The military dog has at last come into his own. The present war has proved him to be a most efficient messen- ger and patrol. At right is shown a courier who knows no. fear At left: Mrs. L. P. Warner who has es- tablished a_ training camp for Red Cross dogs at her home at Hempstead, Long Is- land. With her is Filax, a “star” winner At right: Practising the high jump at the training camp. The majority of the dogs used are sheep dogs and wolf dogs, al- though hounds, collies, and airdales are also apt 2a | £4559 Le Sa 3 a The dogs become very proficient in locating the wounded. They are taught to bring back some article of clothing from a fallen soldier, such as a cap or handkerchief. When ‘they return with no token it is safe to conclude there are no wounded left in that section of the field 815 Coal Mining Machinery Has Increased Our Four cars of coal are unloaded every minute on the rotary dump. The coal falls into a conveyor which leads down the mountain to the tipple house. There it passes over shaker screens and is graded according to size At left: A modern mining machine for un- dercutting coal. It is driven by electric cur- rent and the teeth or picks travel on a chain around the cutter bar. The first cut is al- ways made at the level of the ground Photos © Press Illus. Serv. Mountain women come to the mining camp to trade their eggs, butter and chickens for coal and other merchandise. Travelingis done on horseback and with pack-mule since the mountains are too rugged for wagon roads Coal Output Fifty Fold in Twenty-five Years The coal-cutting machine, cutting to a depth of six and one-half feet at the rate of eighteen inches a minute. The miner with the shovel is clearing away the “‘cuttings” Photos © Press Illus. Serv. As each pit-car passes on the ro- tary dump it is automatically weighed and the tonnage listed by a man who does noth- ing else but attend to the weighing A modern electric locomotive used for hauling Miners trading in a cooperative store where coal from the mines to the dumping house practically everything can be purchased Superstitions of Chinese Gardens Tree worship is common in the East. The photo- graph at left shows the sacred Bow Tree of Ceylon. It is found in the gar- dens of the temples all through China. The little flags hung on strings around the enclosure were placed there by pil- grims and doubtless represent prayers Below: Manikins dressed in growing shrubbery as deco- rations in a garden fe of one of the gam- a tek BEREAPCR bling kings of Y W. Die) tae Macao, China. The ed Q tS evergreens are yoke planted in the flow- er-pot bases and are trimmed into form every few .days. The mani- kins are life-size Photos © Newman Traveltalks and Brown-and Dawson Guarding Property from Cranks and Incendiaries A watchman’s tower, equipped with two searchlights, which overlooks the plant of the Midvale Steel Company. All approaches to the buildings are bathed in artificial daylight at night to ward off spies and incendiaries Guarding the light and power plant of Los Angeles from a possible attack. Notice the two: guards, with guns in their hands, standing at the extreme top of the picture Photos © Int. Film Serv. One guard holds the weapons while the other performs a dare-devil stunt for the benefit of the photographer. These men have to guard the huge gas tank by walking around its top girder 819 The flower ven- der above goes about the streets of Rio de Janeiro balancing the heavy load of growing plants on his head and shoulders until he disposes of it at Merchant burden bearers in the streets of Japan. The size of the load and the variety of the stock are only limited by the strength of the’peddler Photos O Newnes Traveitalks and rown & Dawson Lemonade. ven- ders are as nu- merous in Ja- maica as huck- sters on New York’s East Side. On the balanced kettle there is a spigot which you turn and help yourself We are not un- familiar with the vender of brushes and brooms on the suburban streets of our own United States; but in Rio de Janeiro he adds. chairs to his stock a ere eS ee They Carry Their Shops on Their Heads and Their Backs A ical street sight in South America, a vender balancing Ss eer . a of artificial flowers on his head what seems-to be a perfect garden In Bayard Street, New York, as in Egypt, the beverage that cools comes to you In Trinidad they sell pipe tobacco by the yard or in smaller strips Selling beads in Cairo is a lucrative business for the street boys and girls At left: An umbrella is part of the equipment of the peddlers of Korea A bread seller of Barbados carrying her tray of bread and cake, and her chair Photos © Newman Traveltalks and Brown & Dawson Ue oe The Most Curious of Curiosity Shops In New York City is one of the most curious shops in the world. It is a factory where colossal models are made from metal for shop-keepers’ signs. At left is a pair of opera glasses large enough to fit Miss Liberty. Sheets of copper were rotated against wooden models and blunt tools pressed them into form This giant tooth is made of a com- position substance of white appear- ance so that the dentist’s sign will not tarnish or grow dim. As it is to be suspended overhead, it is made hollow inside so as to prevent it from being dangerously heavy if it should happen to be blown down At left is a jeweler’s sign—a wedding ring as large as an automobile tire. Others have been made large enough for diminutive couples to pose seated on the rim. No idea a merchant may have for an adver- tising design, however freakish, is too difficult for these metal workers of hee ne ele a lt rt hn et tars, An Advertising Sign Factory Showroom The rooster in the picture on the right will soon be the weather-vane on a very large building. Although substantially welded, it is not in one piece. Fully a dozen parts were made so that the completed bird might be an exact image of the real in every detail. Then the parts were assembled and soldered together Animals of every description, jewel- ry of all kinds, eyes of every size and color, miniature automobiles, battleships, houses—in fact rep- licas of any and everything are made upon demand, so that the showroom of ‘the factory resembles an old curiosity shop or a museum Bird forms are hammered out on iron patterns which are cast from the original artist’s model. Often the stuffed bodies of real birds are used, where the reproduction is to be life-size. The eagle in the picture on the right is made of hammered brass resembling polished old gold The Birth of a Butterfly A miracle which you may watch free of charge. LL butterflies must pass through four stages: first the egg; second the caterpillar or larva; third the pupa or chrysalis, and fourth the perfect insect or imago. Some species require months to complete the process. Many pass the entire winter in the third, or chrysalis stage, wound up in cocoons or buried in the ground or under stones or loose bark. But the monarch, or ordinary milkweed caterpillar, passes through all four stages in it necessary to remain perfectly motion- less for fully two hours before and after the process. The skin simply splits down the center of the back and the caterpillar crawls out fully clad in a new suit just like the old one, only more comfortable. This - happens. five times during its caterpillar stage of existence. If you want to witness the miracle of the cater- pillar’s transformation, from three to four weeks and has no objection to being an object of attention during the whole time, so long as plenty of fresh-cut milkweed is provided. Without this it would soon die, for the milkweed leaf is the only food it will take. It spends its entire caterpillar existence on the milkweed plant on which it happened to be born, eating greedily day and night except for a few hours every second day when it stops to change its skin. This molting or skin-changing process is necessary because the little creature grows so rapidly that the old skin becomes too tight, like the breeches of a rapidly-growing boy with a very large appetite. The change itself is quickly accomplished, although the caterpillar finds simply break off the stem of the milkweed plant on which you find the next caterpillar you happen upon, and place the end of the plant in cool water. Be sure and place a fresh stalk in the water bottle each day so that your guest will be well supplied with food, but let the caterpil- lar crawl to the fresh stalk unaided. Handling may injure it. It will not try to leave you so long as you provide plenty of milk- weed. The indications of the end of this first ‘stage of existence will be a restless crawling about on the plant. The caterpillar is looking for the safest place to stay, during the next stage of its career. Doubtless the spot The monarch, or milk- weed caterpillar which completes its transfor- mation in three weeks At left: The caterpil- lar attaching itself toa leaf by means of a sticky, silky substance The pupa emerging from an outgrown skin. The old skin is split open and dropped off 824 ——- = YF, Te ee ee Popular Science Monthly it will select will be the underside of the broadest leaf, to which it will attach itself by means of a sticky, silky substance which it spinsout. Here it will hang, head down, with its body curved up in the form of a hook. istence. The pupa stage of the butterfly ex- i It hangs thus for about twelve days, the shell gradually be- coming more and more transparent 825 hidden that they are seldom dis- covered. You may leave your little guest now for from ten to twelve days, for although there is awonderful change going on inside the shell there will be nothing you can see until about ten hours before the end of the process. Then the shell will begin to change in color from green to brown and will become transparent. You will be able to see the folded wings of the butterfly inside. The time has now come when you must watch closely or you will miss the most interesting part of all. Without a mo- ment’s warning the shell bursts and the but- The newly-ermerged butterfly. Its body is over-large and its wings much crum- pled but as the wings slowly unfold . the body decreases After about twenty- four hours the body straightens out and begins to twitch and wriggle as if the little creature were in great pain. The head and upper portion of the body begin to swell. terfly emerges—a creature all body and with small, much- crumpled wings. The actual time consumed in the emergence is less than one minute. At first sight you may think that something has gone wrong, for the little creature cer- tainly looks deformed and not at all like the beautiful butterflies that we see hovering about the flowers in the fieldsand gardens. But slowly the wings unfold, and as stead- ily the body grows smaller, for the life forces are being pumped from the body into the wings which are to be the Finally the skin bursts, revealing the beautiful’pupa or shell in which the rest of the transformation is to take place. The old skin is dropped off and for three hours the pupa hangs like a little jewel bright green in color and ornamented with a circle of golden spots near the top. Perhaps you have spied one of these little milkweed jewels during your rambles; but common as they are, they are so well The perfect butterfly. fore it finally soars away from the milk- weed stalk sees the most rapid change of all crowning glory of the new existence. ‘While the wings are drying, the little creature timidly tests them, opening and closing them slowly until, gaining courage as the wings grow’ stronger, it soars out into its new life, a new creature gorgeous- ly beautiful and entirely forgetful of its former groveling worm-hood. The miracle has been accomplished under our very eyes and yet we can scarcely credit it. The last hour be- The Wasps of a Modern Fleet Torpedo boat destroyers sweep upon a warship and torpedo it before it has a chance to retaliate. TORPEDO boat destroyer is no longer, as its name seems to indicate, primarily a destroyer of torpedo boats. It isa fast torpedo boat of large size and capable of making prolonged cruises on the seas. Its preeminent purpose is to bag big game, such as dreadnoughts, by torpe- doing them. Its most important armament is torpedo tubes which it carries on an aft deck on both sides of the ship. A number of rapid-fire guns of small caliber are also mounted on the destroyer. These are for fighting with swift, powerful destroyers like itself and for attacking submarines. Such performances, however, are incidental. The sinking of a huge warship during a battle is of greater importance than separate quar- rels amongst small vessels like itself. The Destroyers Lead the Way A number of torpedo boat destroyers accompany a fleet into battle. They are always foremost in the fray. Led generally by a fast light cruiser, the torpedo de- stroyers sweep down upon the enemy’s war- ships at a speed of forty miles an hour. The cruiser endeavors to ward off the counter-attacks of the enemy’s lighter craft and strives to break a way for the destroyers that follow her, so that they can maneuver - into firing position. The destroyers’ work, however, is hazardous, for just one well- aimed shot will send one of them to the bottom. But, on the other hand, they are able to dash about here and there rapidly enough to baffle the enemy’s fire. This initial attack happens before the real battle begins. The slower battleships of the main fleet steam up and open fire upon the big ships of the enemy. Now the destroyers swarm about the battleships, ‘stinging’ whenever they can. Their tor- pedoes can be launched with facility as the firing tubes, after being once loaded and aimed, operate automatically. The torpedo tubes are swung into firing position around their circular track which is mounted on the deck. Each torpedo tube is aimed by sights which are somewhat similar to those on any naval gun. An electric control is thrown in, then com- pressed air enters the rear of the tube and sweeps the torpedo out automatically. The usefulness of these wasps goes even As scouts, they have proved indispensable further than this. A destroyer continually tries to get to leeward of the enemy fleet, where she turns off the draft of her boilers. Clouds of smoke are immediately emitted, which the. wind blows towards the enemy, and which soon envelope the enemy’s ships. The enemy is temporarily blinded by the screen of smoke produced by the de- stroyer though the tops of his masts can be faintly seen. In an instant, the de- stroyer takes advantage of this fact and sends a torpedo, guided by the masts. Smoke Screens Turned the Tide of Battle It was this style of tactics of the Gemaan destroyers which served the Germans so well in the battle of Jutland. At the time their battleships were being hard hit, the German destroyers formed a veritable wall of smoke and enabled their countrymen to gain a temporary advantage. The torpedo boat destroyers have still — another duty equally as important—that of scouting. Their lightness makes them swift and gives them a very large cruising radius. They can- therefore scout far ahead of a squadron and can report their observations of the enemy by wireless. The advancing line of bigger. ships by this means is made well aware of what it is up against long before the enemy ranges into sight. Forewarned is forearmed, and the squadron can prepare itself for the im- pending fight as a consequence. Methods of the Scout This competency of the destroyer as a scout will undoubtedly make her of great — importance in our coast defense. She is capable of discovering the approach of any hostile fleet days ahead of the time that fleet will near our coast. She would immediately make her wireless report, and would continue to follow at a safe distance from the fleet and report its every movement. The destroyer will continually use her long-distance tactics of firing torpedoes in the general direction of the fleet, and there are two chances out of ba that she will hit the ships of the ine. Meanwhile she can give information ye Re eS ers tS Ve | to our submarines to facilitate their surprise — attacks also. : 826 The Vitals of a Torpedo-Boat Destroyer : c : "anon DECK STEERING STATION : a FRAME TO CARRS CANNAS DODGER a. o A {pray BERGE NAVIGATING STATION. WH - : _ COMPASS WHEEL & TELEGRAPES. CALFY F | WRELSOUSE WITH PROJECTOR _ SUEBRING WHEEL , CHARTS AND i AMMUNITION BATCH ay SMUD BOWOFCUN.\ _ < 3E BOW GUN, OF LARGER 4 A: GUIBKE'S OFTEN MOUNTED. | | 1 * Musi 2 VENTILATOR: iy ARE ALTERNATELY IN | TMNES & UPIANES. EACH 4) HAS FAN AT TIS BASE ’ {OM : Zi = = OLD OFT BEOUT 5) te A = : PACE ONL) > e. vege a3 ec a qt > CREWS W) ‘ OR OF KERS = # ae! ik SiC “i Ti EET) | ENGINES! ety aM ROR FET) CPC ERS ie a : OCGUFIES THIS POSITION ON STARBORRD 51D NTILATOR SH <2 4 eis OF .aN PATS | : ,? [ee oa as WATER OKERS” QUARTERS ean ¢ 2 co eee ; UR ~ = OFA Pas; ROO ] © 2. 4 G mt 4 OFFICERS* CHT {| ESSROOM TORE FOLD | DINING ROOM r= = CHOR CHA TERING | ies a CHAIN 10 —\ Ch F - é - OFFICERS’ QUARTERS AMMUNITION HOLD OFFICER'S STATEROOM ° ° CAPTAIN'S ms PROPELLER SHAFTS “tse on = > The torpedo boat destroyer is the swiftest warship. She is designed to sweep upon enemy battleships, and torpedo them before their secondary batteries can effectively strike back. A number of small-caliber guns are mounted on her deck to ward off counter- attacks of submarines and of destroyers like herself. In defending our coasts she is indispensable for scouting for hostile raiders and submarines, and for discovering mines 827 828 Tongs for the Fish That Swallows His Hook HE fish that swallows bait and hook is not a joy to the angler. Getting the hook out is no easy task. But the task is simplified by using the very handy device shown in the illustration. In any case where the hook has not been swallowed further than the gullet the device enables the fish- erman: - to. get hold of it. The device is made from one piece of elastic steel wire bent in the shape of a pair of tongs. The ends of the two arms of the tongs are sharpened to a point. When a fish has been caught which has swallowed the hook, the arms of the tongs are compressed and their ends are in- serted in the fish’s mouth. The arms will then spring apart and hold the jaws open. The two arms of these tongs are also provided with metal plates. These can be used for obtaining a firm hold upon the tongs. The lower plate, it will be noticed, has a set of teeth sharpened on one side, while a cutting edge is sharpened on the other. Thus, this instrument also furnishes a scraper for scaling the fish, and a knife for cutting it open. When the tongs are in- serted in the fish’s mouth they spring back and hold the jaws stretched open The Acids of Fruit Are the Best Mouth Cleansers NLESS the teeth are very badly dam- aged or eroded, the acids of fruit, such as that contained in grapes, oranges, lemons or apples, will be found to be a satisfactory mouth-wash. The advice of a dentist should be sought, however, to de- termine the condition of the teeth and to decide whether an alkaline or acid wash is preferable for the individual case. But there is no question as to the efficacy of the food acids in removing quickly and en- tirely the mucous films that are the first stages of dental decay. An apple eaten in the evening will cleanse the teeth mechani- cally and chemically, and if . .. sae followed by vigorous brush- © “= ing will protect them from bacteria during the night. Popular Science Monthly Catching Flies by the Barrelful with a Home-Made Trap HIS simple but very efficient fly-trap is nothing but a common barrel with a cone of wire screening fastened into one of the ends and extending up into the barrel about half-way. The apex of the cone is cut off so there will be a hole one inch in diameter through which the flies escape up into the barrel. Three little blocks, which hold the barrel about two inches. off the ground, form the en- trance to the trap. A pan con- taining molasses. or other bait is sé€t-oh the ground, and the barrel is placed directly over it. Bent lugs with beveled edges we Fish scaler The flies swarm under the barrel and feed, — but instead of leaving by the way they — entered, their natural instinct will be to fly up into the cone, being attracted by the light streaming down into the barrel Pe a te Set eS a | through .the top, which is covered over~ | with a piece of screening. Set the trap out of doors and forget it for a few days, at the end of which time you will probably have a catch resembling the one illustrated, and your neighborhood will send you a vote of thanks. A — ee At left of the picture is shown a collection of dead flies caught in the barrel trap shown on the right in forty-eight hours Ee ee ee Ts, Pa se eS Making Pearls to Order A Japanese plan for putting oysters systematically to work The work on the oyster farm is done almost entirely by women. Here are women divers, with no other equipment than their baskets, bringing up pearl-oysters from the deep-sea beds world is situated on the Island of Tatokujima, in the Bay of Ago, Japan. The farm lands lie fathoms deep in water, and the crops are lustrous pearls. Oyster shells are lined with a smooth coating which is commonly called mother- of-pearl, or nacre. The oyster builds up this lining layer on layer. If any foreign substance—even a grain of sand—happens to enter the shell of an oyster the oyster immediately begins to allay the irritation it causes by surround- ing it with the material it uses to build up the lining of its shell. This process the oyster keeps up year after year. Pearls are not made by oysters alone. Any mol- lusk may form them, but pearls formed by common oysters and clams are not particu- larly attractive. On the farm at Tato- kujima the first steps toward the production of the pearls are taken during July and August of each year. Wherever the larvae f). of the queerest farms in the A perfect pearl of the variety. The seed inserted inside the shell was covered over with shell-lining of the pearl-oysters have been found most abundant, small pieces of rock and stone are placed. In a little while oyster-spat will be attached to these rocks. Then the rocks are removed to beds which have been prepared for them in deep waters. If they are left in shallow water during the winter the oysters may perish from the cold. They are left in the deep water beds un- disturbed for three years. Then they are taken out of the sea, and into each oyster is introduced a small seed-pearl or a small round piece of nacre which serves as the nucleus for a future pearl. The oysters are then returned to the sea where they remain for four years. At the end of that time they are taken out and the harvest of pearls is reaped. During the four years the oyster has been busily engaged in piling layer on layer of nacre around the bit of foreign substance which was so artfully in- troduced into its shell. The work of the oys- ter-farm is done princi- pally by women. The divers remain under water incredible lengths of time. “Oriental” 829 Protecting Mine Rescue Workers from Gas A new type of breathing apparatus sup- plies oxygen in just the right quantities N January, 1914, the director of the Bureau of Mines commissioned .Mr. William E. Gibbs, a mechanical engineer of New York City, to design a new typeof apparatus for use in mine disasters. The new apparatus has many points of superiority over those which have been used formerly. By means of a special device, oxygen is supplied to the wearer at the rate it is used. While sufficient is available when the wearer is working, none is wasted when he is resting. The harder a man works the more oxygen is necessary for him. The flow of oxygen may be regulated. by means of a valve which is very easy to operate. When this reducing valve is attached to a cylinder of gas, it is possible to admit oxy- gen to the breathing bag in the exact quantity re- quired by the user. The new breathing ap- paratus is constructed of metal, with the excep- tion of a rubber gasket. All parts of the apparatus are mounted on a frame of steel tubing which is carried on the back. When in use, the entire apparatus is protected by an alum- inum cover. The oxygen is carried in a cylinder or bottle at the bottom of the ap- paratus. This cylinder has a stop valve connected with the reducing valve, from which the gas passes by way of a tube past the safety valve within the. breathing bag. The safety valve has a whistle in its outlet. This whistle gives warn- ing of leakage at the reducing valve. When the wearer breathes, air from the breathing bag lifts the inhalation valve and passes through a flexible tube and mouthpiece to the A mine rescue worker wearing the new breathing apparatus. cover is broken away to show interior The reducing valve automatically regu- lates the flow of oxygen from the tank 830 lungs. The exhaled breath passes to the exhalation valve down a flue to the ab- sorber where it is converted, then up through the cooling can, where it loses its heat, and then into the breath- ing bag. When the supply of oxygen in the bag gets low, the flap opens the admission valve and a fresh supply enters. The absorbing can contains twenty vertically arranged sheets of fine iron-wire each other one-fifth of an inch apart. Before being inclosed in the can this bundle of gauze sheets is dipped into , molten caustic soda con- taining twenty per cent of water. The mixture solidifies on the gauze when cool, forming reinforced plates about one- sixteenth of an inch thick. This makes an absorber of carbon dioxide. The plates arbon-dioxide absorber face from which the con- densed and chemically produced moisture con- stantly drains away, car- rying with it the newly formed sodium carbonate. The capacity of this absorber is practically constant, material is all used. The aluminum The apparatus is completed by a pressure gage (finimeter) which is read by touch instead of by sight, because, in the dark- ness of a mine disaster, it would be im- practicable to depend on sight. . This gage the oxygen in the cylin- der has been reduced beyond the point of safety. Instead of a helmet a simple mouthpiece and nose clip are used with the apparatus. gauze, held parallel to Pers © ae ee eee were maintain a uniform sur-— until the active — sounds an alarm when a Making Natural-Color Motion Pictures Light filters through a four-colored attachment which is rotated in front of the projector lenses ATURAL-COLOR motion pictures have not been a success in the past. Color results were too poor to warrant the mechanical complica- tions and the consequent expense of the necessary processes. A new sys- tem is being commer- cialized, however, which is unusually simple and which produces pictures more truly colored than ever before. Like its predecessors, the new system depends upon the fact that beams of certain primary colors when mixed together in varying proportions of intensity will produce a ray of light which will show forth every color in the spectrum. In the new process, the pictures are taken by the camera through a four-colored rotating filter, so that one primary color will affect one picture of the film, a different primary color will affect the next picture on the film, and so on in very rapid succession. The developed film is run in the projector with a corresponding colored filter, and the color pictures are thrown on the screen in the same rapid sequence as they were taken in the camera. Twenty- four color pictures follow each other in a second. The eye has not the time to distinguish one color from the other. They blend all together and pro- duce almost the same effects of color which appeared in the original scene. This process is therefore similar to _ that of the ordinary motion picture, _ with the colored filter thrown in. It is no more complicated. Even the film looks black and white like the others; only of course, each film pic- ture instead of containing the com- plete outline as in ordinary motion pictures, contains only the part of the complete outline which corresponds to one of the four primary colors. The colors which have been found to produce best effects are red and green-blue, yellow and blue. Blends of these produce colors so real- istic that the separate figures on the screen seem actually to stand out in relief. A system as simple and effective as this brings us much At left: The four-colored rotating filter through which pictures in four different colors are taken in rapid succession Photographing natural scenery in all the beauty of its own coloring, by means of the filter camera attachment which “tones in” the primary colors 831 The mechanism of the attachment by means of which the colors are blended on the screen nearer the day when natural color motion pictures will be the only ones in use. Experiments are now under way for perfecting a process of dyeing the black and white film the color of the four primary hues. If this can be done—and recent tests seem to promise that it can—there will be no need of the four-colored filter on the projector, and this natural color system will be simplified so much further. It is planned to take the black and white film which has been exposed in the camera and sim- ply immerse it in vats containing the various dyes. When it is placed in the red vat, for instance, all of the individual pictures of the film, excepting the one- fourth of them which corre- spond to the red portions of the scene, are covered up by small rubber blocks. The dye cannot touch them, therefore, while those parts of the pictures which correspond to the red portions of the scene are colored red. After these pictures have dried, they are covered up and the rubber blocks are removed from those por- tions of the picture to be dyed blue inasimilar way. And this is done for the yellow and the green-blue portions also. The film is thus colored di- rectly and no extra filter is needed on the projector. Popular Science Monthly ‘Editing’ a Motion-Picture Film with a Phonograph — FTER a motion-picture film has been developed and printed it is sent to the general manager or to the director to be “edited.”’ Like an author’s manuscript in the hands of an editor, it is shortened here and there, the captions altered, some parts | entirely ‘“‘cut’”’ or deleted, and the whole film dressed up to suit the ideas of the men closest in touch with the theater-going public. The editing takes place in the projection room, but the altering—cutting the film and changing it—is done in the cutting and assembling room by men who do nothing else. Sometimes the men in the cutting room (‘‘cutters,’”’ in the trade lingo) are so overwhelmed and confused: with orders issued by the studio officials that they are compelled to ask for additional expla- nations. Needless to say this wastes much time. | By means of the phonograph, however, one motion-picture company is eliminating — this waste and saving money. As the director watches a picture in the projection room he utters his editing orders into the transmitter of a dictating machine. The film is then sent back to the cutting room with the phonograph record. As the director watches a picture he utters his editing corrections in- to the transmitter of a dictating machine In the cutting and assembling room the corrections are made from the records of the dictating machine oe a ee eee a The Mangrove Shields of the Savages The implements were crude but the product was serviceable and artistic A scar left on a mangrove tree from the tearing away of bark for a shield of the New South Wales coast fought with spears and boom- erangs, a stout shield was an im- portant part of the warrior’s equipment. White men, with their firearms and their tools of steel, had not yet arrived. The Stone Age had not given place to the Age of Iron. Nobody knows when the first enterprising native discovered that the gray mangrove tree could be made to yield a shield of un- rivaled toughness by a compara- tively simple operation. This con- sisted of cutting through the bark of the trunk an oval groove, or rabbet, two or three inches deep. Into this groove were inserted a number of wedges made from a special kind of stone. By driving these wedges in with a stone ham- mer, a layer of wood was brought away in a single piece; then a little trim- ming and the attachment of a bit of twisted vine sufficed to convert the piece into a perfect shield. In the Port Macquarie district almost every gray mangrove tree of suitable size has been made to yield such a shield, and in many cases two or more shields have been taken from one trunk. The conspicuous scars remain to tell the story of a vanished art. Some of these scars are believed to be i? the days when the savages The perfect shield, trimmed, polished and provided with a handle made of twisted vine tendrils Driving the stone edges in around the oval piece of bark marked off more than five hundred years old, while some are relatively modern, and were made with steel axes. The earliest English shields were “‘bucklers’”’ of lindenwood and were made in much the same manner as these mangrove shields of the savages, except that they were provided with strong iron ribs and bosses. Throwing Heat Overboard from Ocean Steamers N all sea-going steamers, the steam is condensed by sea- water pumped through the surface condensers. This circulating water is then discharged overboard. In the process of condensation, the cooling water taken in at tempera- tures varying from 32 degrees to 88 degrees Fahrenheit according to climatic and other conditions, is raised to temperatures varying from 80 to 120 de- grees and then discharged. This great loss of heat is practically unavoidable. Even on comparatively small steamers, hundreds of tons of heated water are pumped overboard daily. This constitutes one of the greatest heat losses in the operation of steam ma- chinery, although sometimes a portion of the warm water is used for scrubbing decks and for bath. water on passenger ships. 833 How Motion Picture Films Are Made By R. W. Baremore On these big drums the films are dried after developing. They revolve slowly, throw- ing off the water and exposing the emulsion side to a constant current of hot air HE system of taking a motion picture and the developing and printing of the film, follow closely the methods employed by the amateur photographer, even though‘ the film is handled in very much greater lengths. It is run through the motion picture camera in much the same manner as in the lowest priced kodak; it is developed in a tank similar to the amateur’s, although many times larger, and prints are made from. the negative in the well-known way, ex- cept that the positive is printed on a cel- luloid film’ instead of on sensitized paper. As a general rule motion pictures are made in thousand- foot lengths. The reg- ulation camera and pro- jection machine holds this length of film. What are known as “‘features”’ are produced in multiple The developing room. man is agitating the films in a bath 834 reels. Hence the familiar sign “Mary Pickford in Three Reels.”” This, we know, does not mean that Little Mary has been ~ cut to pieces but that it was necessary © to utilize three thousand feet of film to produce the picture. Motion picture film is much more dur- able than that which is used in the kodak, and the emulsion is considerably faster. The film is one and three-eighths inches in width and is made in two-hundred-foot or one thousand feet being secured by cementing five of these lengths to- gether. On both outer edges of the film are perforations averaging sixty-four holes to the foot: These must be made with great care so that the picture synchronizes with the projector shutter. When the cameraman The work- lengths, the full reel eae Popular Science Monthly cranks his machine the film is fed through in a series of rapid jerks, the shutter action being almost continuous. Sixteen pictures are made on each foot of film. The cameraman, having completed his work, the film is delivered to the developing department. Gen- 835 be clean; for even the smallest particle of dust on the film will be magnified many times when the picture is screened. For this reason many special devices have been installed in modern drying rooms to keep them absolutely free from dust and dirt. erally a small piece is clipped and de- veloped to deter- mine light and ex- posure conditions so that. the entire film may be treated accordingly and not spoiled. The developing is done in large tanks. The film is wrapped around large light frames for convenience. Thus mounted it In printing the positive from the negative the ser- vices of real ex- perts are required; uneven. work will produce a bad ‘flicker’ on the screen. Printing has been so highly developed that the old annoying “flicker” has_ al- most disappeared. As in making or- dinary pictures the is easily dipped into the bath, and examined without the direct contact of fingers. When the negative has been developed it is placed in the fixing bath. After that it is thor- oughly washed in clean water. The de- veloping and fixing are generally done in two-hundred-foot lengths. It is difficult to handle any greater length. Large drums made of light metal and wood are used for drying the film. These drums revolve slowly, thus throwing off water adhering to the back of the film and exposing the emulsion side to a constant current of hot air. The drying room must Cementing together the 200-foot lengths of film to make a picture of the standard 1000-foot length emulsion side of the negative is brought into con- tact with the positive film and is exposed to the light. Artificial light is used because it is more easily controlled than sunlight. The printing machines used work on the same principle as the motion picture camera with the exception that they “‘take” two rolls of film, both the positive and the negative. In developing the positive Photographing the titles and subtitles on films from block-letter signs, with a regular motion-picture camera Printing the positive from the negative. The printing is done by artificial light 836 Popular Science Monthly Six Acres of Coal Floating on the Mississippi NLY in the United States can such a sight be seen as six acres of coal floating down a river as a single unit. This is the area of coal boats which the well- known stern-wheel steamer Sprague is capable of handling as a single tow. Four across-stream rows of twelve boats each, make up the principal part. Back of the fourth row, however, eight boats find places together with two barges. Hence, there are fifty-six Washing the negatives in clear water after the develop- Two-hundred-foot lengths are handled at one time and afterward pieced together ing and fixing process. film an additional bath is required to clear the high lights and sharpen the detail; otherwise the method is the same as for the negative. The two-hundred-foot lengths of film are then wound on reels, five lengths being cemented together to produce the standard length of one thousand feet. In every picture ‘“‘titles’’ and ‘“‘sub- titles” are required to explain the action. These are photographed on the film when the other parts of the picture have been taken. The piecing together of the vari- ous sections of film requires the exercise of great care for never are the scenes of a play filmed from begin- ning to end exactly as they are planned by the scenario writer. If five different episodes take place in a drawing room, they will all be photographed at once, even though hun- dreds of feet of landscape film may ulti- mately in- tervene be- tween them. A typical coal boat. travels abreast of eleven others and a steamer It is twenty-six feet wide and fleet. The Sprague has her nose shoved in at the center of the fifth row. The fifty-nine vessels are lashed securely together by lines which run from boat to boat. Al- though the Sprague can push the fleet ahead, her chief duty is to hold back the load. This great amount of coal is handled bya relatively small total of horsepower because the current of the onflowing river supplies a large part of the requisite energy. The big efficient stern wheel of the Sprague stands forty feet high. When bends in the river have to be rounded, it controls the boats by suitable backing move- ments. If the steamer itself goes aground, this big stern wheel may be utilized to drive water in under the stern of the boat to sup- ply a_ kind of miniature flood tide. When the sand bars, swift current and tortuous course down the Missis- sippi_ River, where the Sprague is principally engaged, are taken into considera- tion, it will be granted per- haps that the responsible, difficult task. boats and two barges in the big captain has a_ An Observation-Tower Car for the Army It would serve as an outpost station for wire- less apparatus, signaling and sharp shooting terrupted communication between scattered forces and headquarters, two New York City men have devised a new form of armored car, with folding steel tower for wireless apparatus, signaling, observation and sharp shooting, and have offered it to the Government for immediate use. National Guardsmen, after putting the car to a severe test recently, reported favorably upon it. The tower of the armored automo- bile is of steel and extends twenty-five feet in the air. When the ma- chine is in motion and the tower is not used for observa- tion purposes, it may be folded back as shown in one of the illustrations. On the top of the tower, when it is extended to its f-a-1 length, $= 2 small platform with just enough room for one man and a machine gun, the latter if capable of be- | ing used for / ff offensive or de- | fensive pur- r | NO enable an army to maintain unin- The armored tower car traveling at high speed with the top portion of the steel tower folded back poses. When . . : Phots@Amer. Signaling and observation work the car used for Press Assoc, § > may take up a certain position and be con- sidered as an outpost station, or it may move about from one section of the coun- try to the other, keeping in communica- tion with the general staff by means of its wireless apparatus. Furthermore, it may be used with equal facility at night, signal- ing being carried on with the aid of search- lights or by wig-wagging with lights instead of the usual flags. With the car traveling at high speed a man can take up his position at the top of the tower and wig- wag information to other moving observa- tion towers, or obtain military knowledge Srapicnek Uneaten wilde thetic” as 0 while moving through the enemy’s country signaling station. At night colored lights at great speed in the event of the failure of ‘would be used instead of the flags the ordinary means of communication. 837 STRIPS OF HARDENED RUBBER { eat “Sa Bao WHEEL RIM RUBBER STRIP- ~~ — a os] METAL CUIP-$4)) ~ Thick strips of hardened rubber placed across the face of a tire prevent skid- ding and pro- The Latest Additions to the Constantly-Increasing A protective pad for several styles of heels, which saves the shoe when the driver is operating the clutch or brake tect the tires lever of the car from punctures Accessibility to every part of the motor-truck power- plant is secured by hinging the crankcase on one side > and then elevating it with a small screw-jack, as shown AIR EXHAUST TO LOWER JACK A combined auto- mobile pump and jack. A single han- dle operates the device for either purpose. It is car- ried with the tools CHECK VALVE A lighter for gas headlights on automobiles. Wires from the spark - plug « cir- cuit connect with each burner A motorcycle limousine with seating capacity for three passengers. It is a three-wheeled affair How an American automobile party crossed an African river. A flooring of planks was placed on an ordinary flat-bottom row-boat and the automobile was balanced on it. The craft was then pushed across by natives and the landing was made at the other side by utilizing heavy beams 838 ee ee ee ee =) 4 is eel VTS ee oe ae ae eee Variety of Automobile Accessories and Conveniences << > ay + ‘ 3 Ss (Seas tah | s Capstan hub caps make it easy to extricate a mired car. A rope is attached to each of the rear wheel cap- stans and the free ends to a stake or a tree Spark con B® Steering control column, A triple tire wheel as standard equipment for trucks of large capacity. It gives a consider- ably greater mileage than the dual tire wheel Cylinder An _ automobile lock which se- cures the stee: ing mechanism, gas, and spark control against A vacuum cleaner for the automo- bile. The pump- ing action of the engine is utilized to create the Single chains attached to the spokes have leather- operation. It is vacuum. The de- covered fasteners which do not injure the rim. attached to the vice can be ap- They cannot strike the mudguard and can be steering post plied to any engine fitted on solid as well as on the pneumatic tires below the wheel 839 The World’s Most Powerful Searchlight It sends forth a beam as brilliant as fiercest sunlight T is ten feet high, its mirror has a diame- | ter of five feet, and it weighs three tons. Its beam is as brilliant as the sun at eight o’clock in the morning or four in the afternoon, New York latitude, and you can read a newspaper by its light thirty miles away. The heat of its focused beam is so intense that it will set paper afire at a dis- tance of two hundred and fifty feet. It has a candlepower of more than one and a quarter billion. These are a few astonishing facts about the Sperry search- light, the invention of Elmer A. Sperry, of Brooklyn, N.Y., who is already known as the inventor of the air- plane stabilizer and ship gyroscope bearing his name and the first elec- tric arc light. When the last big air raid over London was made by Zep- pelins, the Sperry search- lights bathed the big dirigi- bles in beams of light they could not escape. According to some London accounts the Sperry searchlight is the Zeppelin’s Nemesis. One of the most powerful beacons along the coast is the Sandy Hook Lighthouse. But the Sperry searchlight is twenty-two times more bril- liant than that. light. Were the Sperry lamp substituted for the lighthouse beacon, a ship passing out to sea could be bathed in light until it disappeared below the horizon. By swinging the light back and forth across the sky it has been made visible one hun- dred and fifty miles away. For Navy use the Sperry lamp illuminates a target ten times more brilliantly than any other pro- jector devised. Equipped with a carriage that permits the lamp to be turned in a circle and in any direction up to ninety degrees, the giant searchlight is of the greatest value in detecting aircraft. The operator can not control it near at hand; the great heat prevents that. He must stand fifty feet away. At that distance he is able to focus accurately upon any moving object. Because the rays projected by the lamp are Elmer A. Sperry, inventor of the greatest searchlight nearly parallel, there is no diffusion of light overa wide area. The beam is concentrated. When the searchlight is being operated, the temperature of the arc is nine thousand degrees Fahrenheit—seven thousand de- | grees higher than the melting point of the metal holders of the carbons. Conse- quently, in order to prevent these parts from melting, a current of air is forced, by means of a motor-driven blower, through the carbon supports and discharged through the heat- radiating disks that surround the holders. In the Beck lamp the holders are prevent them from melt- ing. The several factors the Sperry lamp so power- trodes, the special carbons used, the manner in which they burn and the parabolic mirror. A colored glass peep- sight enables the operator to watch the arc without being blinded by the glare, or the upon a ground glass outside the lamp. An iris diaphragm similar to that used on cameras, regulates the light. Stand in the beam of the Sperry lamp at any distance closer than three hundred feet and your skin will be burned. At that distance the skin peels. The great heat of the arc is due to the fact that it produces a crater which more nearly approximates the mathematical point of light than does that — in other searchlights. The candlepower is more than three hundred and twenty thousand per square inch. Designed for naval and military pur- poses, the Sperry lamp, in addition to locating enemy forces on land and in the air, is useful also in throwing a screen of powerful light in front of the enemy. It is impossible to see through its concentrated beam. Allied field forces have mounted the lamp on armored cars and have found it available for signaling at any distance up to one hundred miles. 840 | sprayed with alcohol to which combine to make ful are the small elec-. arc is reproduced by lenses — rare © RS ee em Ce eee Cee It Will Burn Your Skin at Three Hundred Feet AIR CURRENT OUTLET S) FUL so A SILVER CONTACTS TERMED “BRUSHES * WHICH CONV! ARRANGEMENT OF CARBON HOLDERS IN THE SPERBY LAMP. cee] | [M-Bi-ty 5 ttzcinc cuntini To campona Ant sttAcneD To z ia? COPPER BARS SUPPORTED BY SPRINGS PSGUA STN A CA Eo ee ’ 5 oii ING POSITIVE CARBON AIR CURRENT OUTLET. HOLDER COOL as a ° ernest FLL mage” eet Sw o FEED ROLLERS WHICH MOVE eae ae = FORWARD AS egal MED = ee Ce SPP Sc FORMING LARGE COOLING i = Z J Lo OK SUNTACE BETWEEN WHICH AIR f Se CURRENT PASSES —— = a i STAR-WHEEL OPERATED BY TRIP- Led : REIN PING AT EACH OF EXHAUST AIR CURRENTS WHIC THAT ¥ COOLING THE CARBON HOLDER PASSE: INCLINED POSITION OF POSITIVE & NEGATIVE CARBONS TO THETR GLOWING TPS TO THE MIRROR. Be me f : 2 ' er = : 3 os a Pr: NARROW NESS OF THE SUPPORTS... “yf =| CONTROL BOX. [D POSITION OF CARBONS FAN FORCING AIR ED BAD SHADOWS IN THE BEAM THROUGH THE HOL- LOW UPRIGHTS SUR EARLY FORM OF LAMP... NG SR" ? CRATER IN rare CARBON ONLY. FORMS SEMI-LUMINOUS FL ME CE OF FROM NEGATIVE CARBON ¢ “7 —_—- ao) ° ay 4 / POSTIIVE \\ ff . ie MIRRO \ r pire =a \ nb, , & CRATER OF SPERRY LAMP. 105,000 C.P. HAND-FEED OF TIVE POSITIVE CARBON \. fs SR coo Devic ALLOWS si eaten ae se THREAD REGULATING POSITION OF CARBONS ' _ CARBONE. ay JZ The new Sperry searchlight lamp and its predecessors. The trend in lamp design has been to provide a more intensely luminous source than that of pure carbon. Until recently this was thought impossible, because carbon possesses the highest melting point of any known element. But the newer lights, such as the Beck lamp shown above, and the Sperry lamp, have kept their carbons and metal parts from melting by ingenious means. In the Beck lamp an alcohol spray is used; in the Sperry lamp constant currents of cool air are forced through the carbon supports 841 Gathering Oysters by Submarine A peaceful occupation at which the subrnarine is so efficient that it promises to revolutionize the entire shellfish industry uction pipes 2=Compressed air pipe * When traversing a good bed the submarine will suck up five thousand bushels of oysters in an hour, leaving the bed clean-swept. For the most part its inventors thought only of blowing up ships, notwithstanding the dramatically success- ful trip of the Deutschland. Probably the only inventor who believed in its peaceful, industrial possibilities from the very be- ginning was Simon Lake. He has sug- gested the use of the submarine for polar exploration, for ferrying supplies across ice- bound rivers, for seeking sunken treasure, and for digging oysters. We have already pictured his transatlantic submarine freight carrier—an older invention than the Deutsch- a ke submarine is primarily a destroyer. SA. It is not diverted from its course by wind or tide land—and on this page we illustrate his submarine oyster gatherer. Preliminary experiments have demon- strated to Mr. Lake’s satisfaction that when the submarine is at the bottom of the ocean, the oysters can be sucked up into it on the vacuum cleaner principle. When traversing good ground, the submarine will suck up five thousand bushels of oys- ters in an hour. This means that in one hour a mass of oysters will be collected which, if compactly piled in a cylinder one foot in diameter, would require a cylinder one and three-quarters mile long to hold it. x ~ ———————— a ee ee Oe ee One an oe ay ea ee i Popular Science Monthly The submarine which will accomplish this employs essentially the usual pro- pelling and diving apparatus found in sub- marines. Its hull is different, however. Nearly the entire bottom-half of the central portion of the boat is given over to the two storage holds. These holds are water- tight, but their bottoms can be opened to the sea. A central observation chamber between the holds also opens to the sea. A large-toothed driving-wheel is mounted at the bottom of this chamber, to help drive it along the ocean bottom. Com- pressed air is turned into the observation chamber to push the water out, and powerful electric lights are then turned on. The opera- tor stationed outside of the glass walls of this chamber can plainly see the bottom. When an oyster bed is reached, the storage holds are quickly opened. Sea water rushes in. Large centrifugal pumps are started. They force great streams of the water out so that equal streams of water can be sucked in. The inrushing water carries the oysters along with it. Thousands of the oysters will pile against the wire screening which lines the storage holds in front of the water exits. The submarine thus cleans up the oyster bed The spiral spray creates the vacuum which sucks up the dust Attach This Hose to Your Hydrant to Run Your Vacuum Cleaner VACUUM cleaner has been invented by Beecher W. Junk of Toledo, Ohio, which can be operated wherever there is a hydrant in your house. A pipe of the right diameter is screwed into the hydrant’s mouth and runs down to A Flashlight Advertisement on the Cashier’s Register FLASHLIGHT change holder makes an attractive and useful decoration for showcases or for use in connection with the cashier’s register. When the change is depos- ited .in the holder by the cashier, the coin forms a contact, causing a sign to flashinto view. Theadver- tisement may be a colored photograph, a drawing, a slogan, or any other thing desired. It comes to the buyer’s attention in such a manner that he is bound to notice it, and generally when he is in an agreeable frame of mind. When the coin is deposited an electrical contact is made and the sign is flashed into view the bottom of the sink. A spiral nozzle fits the pipe just below the mouth of the hydrant. An angu- lar pipe opens into the vertical pipe immediately below the nozzle and slopes up to connect with a rubber hose on the guiding rod. To clean the room, you turn on the water and guide the rod over the carpet. After traversing the spiral nozzle, the water whirls around and passes the opening of the angular pipe, forcing out all the air near it. The vacuum so created starts the air flowing in the rubber hose. 844 A jointed ring buoyed up by two floats rubs against the pile and scrapes off marine growths Making the Waves Scrape Marine Growths from Piles ° Bes protection of wooden piling on wharfs and piers along our coasts from barnacles and the ravages of insect borers is a vital matter. Lives are endangered and much property is lost through.worm- eaten supports. For that reason a “‘pro- tector,’ installed at various points along the Pacific coast by Alva L. Reynolds, of Long Beach, California, is attracting considerable attention. Popular Science Monthly How an Entire Railroad Car May Be Moved by Hand A JITH a tool such as that invented by Charles McCarter, of Decatur, IIli- nois, any one can move a railroad car by hand. It has a clamp that firmly grips the car wheel when a lever (shown in the hands of the man in the photograph) is lowered. The lever has its end secured to a crank pivoted on a triangular wheeled frame, the wheels of which always rest on the track rail. When the lever is raised, cranks release the clamp from its grip on the car wheel. As the lever is arranged outside of the track it may be operated without any hin- drance where two cars are coupled, for there will be ample room to move the lever. The car wheel is rolled three inches at one stroke of the lever. When the car wheel moves, the car-mover rolls on the rail and they both travel to- gether. One man can move the heaviest loaded car on any kind of track. Slippery rails do not hinder the operation, and there is not the least danger of the operator getting his fingers or toes mashed or being hurt in any way. The tool and its frame are light enough to be easily carried where needed. It is especially useful where a car switched on a siding has come to a stop a few feet short of the desired place for loading or unload- ing. With the mover the car can be placed exactly where it is needed in a few minutes’ time and without requiring the services of more than one man. The device consists of a jointed ring’ which encircles the piling loosely and is buoyed up by two floats, which look like big wooden baits on rat-trap hooks, and prevent the iron ring from slipping to the bottom of the pile into the mud. Up and down with the tide goes this wooden-baited ring, con- stantly rubbing itself around the post and preventing the entrance of wood-borers, or, if the post be old and already covered, scraping off the ma- rine growths and undesirable attachments of all kinds. At each stroke of the lever the car wheel is moved three inches. Slippery rails do not hinder the operation sa ee ee ee ee ae ee down in a steel Eliminating Automobile Valve Trouble . Valves made of pure carbon are self-lubricating LL valve grinding, trouble with weak A valve springs and loss of power through improper seating of valves if the motors were would be eliminated fitted with the these ports to the large top of the valve. A similar passage is cut from the other port to the bottom of the valve, the passages being on the same side of the valve as the port in each carbon rotary valve shown in the accompany- ingillustrations. It is made of pure carbon in the shape of a cone with the apex cut off and is run small end > seat placed be- tween the curv- ature of two or more adjacent cylinders. It is carried on a ver- tical shaft re- case. The open- ing in the top serves as the ex- haust port and that in the bot- tom as the in- take port. _ At the begin- ning and during the suction stroke of the motor, the valve is rotated in its seat so that the intake port in the valve is made to coin- cide with~ the volved by a pair of bevel gears | driven off the en- gine crank-shaft. Two Boston men are the inventors. Carbon is one of the best lubricants known and has great heat resisting properties, so that the valve is practically self-lubricated and is yet able to withstand the heat of the ex- haust gases without warping and sticking in its seat, a trouble heretofore always ex- perienced to some ex- tent with metal- against-metal rotary valves. The illustration shows a four-cylinder motor with its cylin- ders cast in pairs and a valve for each pair. _As shown in the draw- ings, the valve has two rectangular ports cut in its curved sides at points 20 degrees A passageway is cut from one of apart. A four-cylinder motor with the cylinders cast in pairs. There is a valve for each pair The two rectangular intake and exhaust ports in the curved sides of the valve Exhaust manifold Intake and Lo i exhaust passage Water == Be From SS carbureter = | Squared valve - | E= stem Spark plug A cross-sectional view showing the construction of the valves and their relation to the engine cylinder 845 port in the valve seat which opens into a pas- sage leading di- rectly into the head of the cylinder. The gas passes up through the crescent-shaped opening in the bottom of the valve, through the coin- ciding ports in valve and seat and thence through the passage leading to the cylinder where it is ex- ploded in the usual man- ner. Then as the valve is rotated at half the speed of the motor, the latter has its compression and firing strokes before the valve has made one- half a revolution and the exhaust port of the latter is brought opposite the valve seat port to permit the burnt gases to pass through the valve and up into the exhaust manifold. The following half revolution of the valve takes care of the second cylinder. 846 The air supplied to the patient is me- chanically cleansed by the filters, made chemically clean by the action of the rays from the electric light, and then carried to the patients’ lungs through the mouth Apparatus for Puri- fying and Medi- cating Air N bronchial and throat affections and directly after suffoca- tion by gas, prepared air is of the greatest value, especially if it is medicated. The appa- ratus illustrated makes it possible for a gas- stricken victim to be re- stored to consciousness in a minimum of time. A coarse mesh at the point of entry contains a packing of lump char- coal. which removes gases, excess moisture. and solid matter. Solid calcium chloride thor- oughly dries the air and then a layer of cotton wool filters it and pre- vents the solids from falling into the reflector chamber through the holes surrounding the reflector rim. The air comes through these holes and is ex- The screens may be rolled up like a shade on cleaning days and left in ; their cases when the season is over rolled up in the cases. Popular Science Monthly posed to the glare of a tungsten lamp intensified by a bright metal reflector. The action of the rays combined with the heat of the lamp kills the germs and organic matter remaining in the air. A suction fan draws the purified air from the reflector chamber and dis- poses of any remaining particles by the centrifugal throw of its blades. This tends to push the air along its path, relieving the patient of much of the labor of drawing the air through the apparatus. In the final stage, the air passes through a tube into a saline or oil solution in a bottle, from which it is passed to the patient, through another tube. ALUMINUM CASING An Improvement Window Screens CER has adapt- COTTON oT : ° 4 = ayes BATTING ELECTRICWIRE ed the principle of COTTON FILTER the ordinary window shade roller to the mosquito screen. The roller used is of much larger diameter than that of a window shade, and it is fitted with a much more powerful spring. Moreover, it is entirely enclosed in a metal casing, mounted directly outside the win- dow. The screening it- self is reinforced by thin- edge strips of flexible metal. When the screen is pulled down it is fast- ened in place by a catch on the bottom window- sill. When the cleaning day comes around, in- stead of having to re- move each screen from its fastenings in order to get at the windows, it is necessary only to roll up each one in its turn. When the mos- quito and fly season is over the screens need not be taken down and stored. They may be left on an Old Idea for SLE V. MER- . ui) Se eee aa eS —— a Protecting Ships from Torpedoes A U-shaped buffer is provided, in which the hull of the vessel floats and the mine? Can nothing be done to protect a Lusitania or a Laconia ? Naval architects have succeeded in giv- ing warships some measure of protection by subdividing their hulls into literally hundreds of Tr there no defense against the torpedo nected by a bottom which lies beneath the ship’s hull. The U-shaped structure lies at a suitable depth so that the ship to be protected can be floated in and secured to the structure. Since the protecting struc- ture is merely a shell, it offers but little resistance to cells. When the water. the battle- It is evi- ship Auda- dent that if cious struck a mine she stayed afloat a torpedo or a mine were to explode, for over four the U-shaped hours be- protector cause of her would be multi -cellu- destroyed, lar construc- but the ship tion. Why is. itself would not the same be saved. idea applied Evenif the to merchant ° ship were vessels? Sim- damaged to ply because some extent it is prohib- the injury itively ex- would prob- pensive. ably beslight Even so, and could the Lusitania be easily eee at kt The protecting U-shaped structure i d of sid . ; | poker i -sha € 1s composed of side walls Ee SAY ie =» Sega aumseeed Gerva. DoricaMhacath the aivatai. it is 4 Sane Pa | P she had a double hull and was subdivided after a fashion. Because she was not minutely subdivided, like a battleship, she went down in twenty minutes. Why not use torpedo nets? They have proven of no avail. But the idea of catching-a torpedo and stopping it before it ever reaches a ship seems sound. Ac- cordingly, we find that Thomas Thurston, a naval architect connected with one of the large British shipbuilding firms, has in- vented and patented a system for protect- ing ships from the effects of a submarine explosion, which system depends on the principle of providing a buffer for a ship. As the illustration shows, Thurston’s buffer is a U-shaped structure, not unlike a floating dry-dock, in which floats the hull of the vessel to be protected. This U- shaped structure comprises side walls con- mere shell, as may be seen from the diagrammatic drawing The Perfect Poise—How We Can Attain It OR the perfect physical poise we don’t need to study pictures in the modern magazines. The ideal form is well expressed in sculpture dating back to 500-600 B. C., when the Spartans were masters of Greece. These ancients carried themselves in such a way that the muscles, organs, circulation and even the brain and nervous system were placed in harmonious relationship. How can we attain the same poise in walk- ing? Briefly, by setting the shoulders back and squaring them evenly, by carrying the chest high and well arched forward, by keeping the stomach in and the neck per- pendicular, like a column, and by forcing the chin in. Whether sitting, standing or walking, these principles involve a correct and graceful carriage. 847 848 Popular Science Monthly ROS. irregularities of the stream Z beds. The frame which sup- ports the cutting blades is constructed of two vertical irons and may be swung from a lever pivoted in an upright. — The paddle wheel is carried on a frame capa- ble of adjustment to any ‘desired depth. The wheel is driven from the _ gas- oline motor by a’ gearing and chain device. Two sep- arate countershafts are used for this purpose. so as to give the necessary speed~ reduc- tion when cutting. The cut- ting frame may be lifted out of the water when not in use. The blades fold up A reaper boat cutting aquatic growths. The blades lie near the alongside the frame. bottom of the pond and operate automatically by motor-power Clearing Out Ponds and Lakes A Willow Basket as Large with a Reaper as a House E are familiar with all sorts of reap- foe huge basket, a product of a tribe ing and harvesting machines de- of the Ponca Indians of California, signed for use on land, but a reaper boat weighs 325 pounds when empty, notwith- is something decidedly new. A Frenchman standing that it is made of light osiers, by the name of Amiot has devised a boat _ skillfully intertwined. It is six feet from which is equipped with a set of bottom to rim, and its top cutting blades for use in re- is three feet higher. moving aquatic growths It is now the property from ponds and arti- of the Institute of ficial lakes. Arts and Sciences The cutting blades, g of Brooklyn, New which are modeled * York. Before it after the fashion of could be loaded on reaper blades, are a box car for ship- operated by a ment east it was motor on the boat. necessary to widen The boat is about the floor of the twenty feet in car. length, flat bot- These huge tomed and narrow willow ‘‘gran- at the front and aries’’ of the rear. A paddle Poncas are gen- wheel placed in the erally mounted on front of the boat is rude platforms driven by a gasoline reached by ladders engine. to keep them dry. The cutting bars are Each basket has a placed at the rear end of rain-shedding cover the boat on a vertical made of grass or cedar frame. The blades are sage The grain piss made in different lengths : ; : in them remains dry and with different curva- pegs powered age sige and in perfect condition tures to adapt them tothe used by the Indians as a granary indefinitely. -an hour back, represents central Popular Science Monthly _ Making Your Watch Tell the Whole Truth HE average commercial traveler who journeys about the United States has to keep a close watch on his timepiece to see that it is telling the truth. There is an hour’s difference in time when you enter and leave some cities and it’s an im- portant matter that you do not forget to set your watch back or forward an hour, ac- cording to which way you are traveling. If you over- look it, you may miss a train. An express official who travels almost all the time and is so busy that he sometimes forgets to change his watch at Detroit, Mich., for instance, or at Dodge City, Ia., has frequently had an experience of this kind. Sometimes he has arrived an hour ahead of time or, perhaps, an hour after a train has left, giving him time enough for reflection. Recently, he conceived the idea of mak- ing his watch tell all four different. times— Eastern, Central, Mountain and Pacific. He went to a jeweler and had extra hour hands put on his timepiece— each of a different color, so that he can recognize it at a glance, on the face of his watch. For instance, the ordinary hour-hand, set at Eastern time, is silver; a blue hand, set time; a red hand, for moun- tain time, is set two hours back; and a green hour hand, three hours ~ back, represents Pacific time. You can do this to your own watch. The jeweler will make a set of hands of these colors and alter your watch fora consideration of a few dollars, so that when you go traveling it will not be necessary to dis- turb the mechanism of your watch by setting the hour- hands back and forth frequent- _ ly, according to whether you are in De- troit, Chicago, New York, Denver, San Francisco, or other places on the map. But such an arrangement would be parti- cularly useful only to the itinerant sales- man or other frequent traveler. You can have addi- tional hands made for your watch so that it will indicate the time of the locality you are in The tests relate to ice consumption, temperature distribution, and air circulation within the refrigerators. inside each refrigerator is connected with the galvanometer Equipment How the War Department Tests Its Household Refrigerators CCORDING to the Bureau of Stand- ards, the ordinary household refrig- erator, even of the best make, is by no means as effective in the saving of ice as might be desired. Before awarding contracts to supply the army with refrigerators, the War Department uses temperature-measur- ing instruments for testing each type offered. Thedimensionsof the refrigeratorsare measured, as well as the tempera- tures inside and outside, the size or area of ice used, the amount melted per day, the amount of air circulating through the food chambers, and, -finally, the heat transmission of the refrigerator walls. The temperature measure- ments are made by means of thermocouples (instruments for noting differences in temperature by electricity), several of which are mount- ed inside each refrigerator and several others at various points outside. By this means all measurements are made with a single galvanometer (an instrument for measuring the intensity of an electrical cur- rent), shown on the tripod stand in the illustration. The lead wires from each of the thermocouples, some thirty in number, are connected succes- sively with the galvanometer by means of the simple switchboard on the table. The temperature is measured in the air entrance and the air exit to the ice chamber. GIGANTIC raft capable of holding ; all the passengers and crew at one _ time, is the newest life-saving inven- tion of Nathan Rubenstein of New York. It consists of a number of wooden sections joined together and mounted on airtight pontoons set down on the uppermost rear deck of the vessel. When not in use as ff A Raft-Deck Life-Saver In a disaster at sea a detachable upper deck slips over the side of the ship and becomes a giant raft In less time than it would take to” man and launch a single lifeboat, the raft is floated with all on board raft is equipped with small cabins for food and with a com- plete wireless telegraph outfit. ._ The evident advantages of a @. raft of this type are comprised ‘in the fact that it saves life wholesale and is launched and manned with all on board in less time than would be required for one of the twenty or thirty conventional life-boats that are usually carried. The fact that it takes up no space that might be used for other purposes is also an advantage, and its wireless out- fit is perhaps : Raft section a raft it forms an integral part of the its trump Rack bar ship and is used as a promenade deck. card. SSS When a vessel has received its death Against LT Ef wound and lists dangerously over to either x Guard rail Cabin po. Gear Sectional raft ‘ ES Stops Rollers Deck we a 7 > : Vv cS OU a | an eel Ste Se os ° flocks 7 ATS: Wee ge < 4 eeeiac~ Mdler Releasing ‘Mi Stan foe cable ig gl e S a wy sec iat vais Diagram showing the launching ways on which h d oes. Raft tilting the floatable deck is mounted on the vessel these advan- re een tages it is wise. side, the raft is merely released from its moor- ings so that it can slide over the lower rail into the water. When it has been launched successfully, the passengers slide down to it in canvas bags or on ropes and sus- pended seats to consider the fact that such a raft places the passengers and crew in the position of the eggs which the old woman car- ried all in one basket. Itisa case of all be- ing saved or none. Again, due to its great size, it is liable to be damaged or to capsize like breeches buoys. The 850 The deck-raft as it appears ordinarily on an ocean liner. It is used as a promenade for the ship’s passengers or to be torn from its moor- in launching, —————— ee ee a a a ee ae ——— sr NY an 4 _— eS eS Popular Science Monthly ings during a storm at sea. It is not an unheard-of oc- currence for mountain-high waves to strike a ship with a force of several hundred tons and make her tremble and shiver down to her keel. In such a case there seems little to hinder the raft from jerking free and sliding of its own accord down into the sea, leaving the passengers and crew without hope of escape. Even at best the chances of launching it suc- cessfully in such a sea would be small, in spite of its speci- . < r ally devised launching ways. In place of a second man to guide the large saw, a carriage is substituted on which the saw slides back and forth A Fountain Shoe-Shining Outfit. It Won’t Soil Your Hands HE trouble and the discomfort that accompanies shoe-shining at home can be eliminated by a fountain-brush that Theodore F. Gensmer, of Minneapolis, Minnesota, has invented. A long tube of paste fits safely inside the polish-brush handle. The simple turning of a finger grip at the end of the handle pushes in a piston and forces as much paste down into the bristles of the brush as is wanted. When the tube has been used up, another is inserted. In this way the hands do not come into contact with the polish or the shoe. Furthermore, the device prevents any waste of the polish, since the finger grip must be operated before the polish is forced down into the bristles. The felt brush polisher gives a bet- ter finish than the usual cloth. The paste container fits into a metal - lined cavity in the brush. A One-Man Saw for Felling Large Trees LL large cross-cut saws for felling big trees require two men to guide them. By the use of an ingenious guiding mechan- ism, however, Frank C. Ridson, a Can- adian, has been able to do the work with one man. The end of the saw is simply bolted on a carriage which moves hori- zontally back and forth on guide rods mounted on the tree when the sawing is in progress. The guide rods swing on a spindle which is driven into the tree. They are held steady by a lower sleeve to which the rod sleeve can be locked. A strong spring fastened in back of the tree holds the rod sleeve and prevents its turning. The rods guide the carriage in a direction parallel with the cut- ting movements of the saw. This reduces the sliding friction to a minimum. By a simple twist of the grip on the handle a piston is forced up in the cylinder and the paste is pressed down to the bristles. It is spread with the dauber as shown on the left. A felt brush is used for the polishing and shining Do It with Tools and Machines : Peepholes are attached to the arms to measure the exact heights of trees, poles, buildings, hills, mountains and landmarks Finding the in- clination of a plane with a simple com pu- ting square A handful of sparkling diamonds used by an automobile manufac- turer in truing grinder wheels Jar for holding water to supply moisture at all times to the intake manifold of the automo- bile engine An apparatus for electro-me- chanical mas- sage. It is used to relieve neur- asthenia and constipation Manufactured screws are thrown in the hopper and the machine counts and delivers them to the packer A trestle with toggle levers to hold ff : A quick-return screwdriver is a valu- a board during the planing process © able addition to the automobile tools pola 3. : Do It with Tools and Machines The paper-roll holder has a cutter attachment A two-way valve tool used to remove the which is operated by a slight pressure of the cotter or to compress a spring by the action thumb on the handle that turns the roll of a_thumbnut, the jaws working both ways Position of file for % teeth sharpening 2 : File socket Filein posrtion for saw jointing File By the use of this handle a three- cornered file may be held in two different positions for jointing Valve disks which have and filing the teeth of a saw A flashlight holder for become pitted and the use of the mechanic rough can be quickly to enable him to direct smoothed up with this the light to the exact reseating attachment spot where it is needed With this tap-wrench holes may be bored and threads cut in places otherwise inaccessible The workman on the left is carrying his portable stand equipped with a vise to a pipe-cutting and threading job. On the right he is shown with the stand erected. Here it is being used as a pipe-bending device 853 A wonderful mechanical system which does away with the services of thirty men Sorting Mail with a Typewriter 7 i a. r 4 . 2? he » Rs Fs. ce BG we * » The endless chain conveyor which carries the letters to the ‘‘buckets’”’ for distribution HERE is a new mechanical sorting and distributing system in the Chi- cago, Illinois, post office. It is a device by which letters to all.parts of the globe are separated into 256 different divi- sions—a sorting. which at present in all other post offices means two handlings of each piece of mail, and the employment of a small army of case clerks. Hoboken? Honolulu? Zip! Zip! Two taps on the typewriter keyboard, and the letters are on their way! An endless chain conveyer travels hori- zontally around two drums, at the left of the operator. This endless belt carries a series of metal pigeonholes below a smaller number of large containers known as “‘buckets,’’ which are the first destinations of the sorted letters. At the bottom of The letters are first stacked mechanically and faced up so that the address isin sight. The 256 keys control as many combinations of rods each bucket are four small rods project- ing downward. Each of these rods works independently of the others, and is capa- ble of four different positions. Thus we find 256 possible combinations. The metal vane, swinging back and forth, deposits the letters in the buckets, where they are taken care of by the rods. The letters come before the operator- of the keyboard after having been stacked by a mechanical contrivance which faces them up and presses them in with sufficient ten- sion so that the address of the foremost missive is in plain sight always. The keyboard consists of 256 different keys to correspond with the 256 combina- tions of the rods. The means of transmission from the keys to the rods is through an arrangement of horizontally placed levers along which the four bucket-rods pass. The operator glances quickly at the ad- -dress on an envelope, presses the key which corresponds, and the letter flashes away. The one pressure sets the horizontal levers at the correct combination. These act on the four rods of the bucket so that when the metal vane carries the letter to the bucket, the rods pass it on down instantly into one of the pigeonholes beneath. The same pressure of the key brings the next letter in position. 854 ei el Ae hy ne ee eee Oe Pee Tet) ee ee ee et es " rT a” eee 9 Bhi, ’ vibration, the springs, no _ must absorb sidewise blows as well. ig Popular Science Monthly A New Airplane Wheel Which Absorbs Shocks N all wheeled vehicles it is essential that shocks should be absorbed as far as possible by the tires them- selves. In other words, the brunt of the shock should be absorbed before it is com- municated to the springs and thus to the body of the vehicle itself. For, when the axle and the wheel are set in matter how plastic, will com- municate a part of that vibration, to the body. This is equally as true of airplanes as of automobiles. With pneumatic tires the main force of a concussion is immediately absorbed by the resilient rubber. That is one reason why airplane wheels are equipped with pneumatic tires. No wheels are exposed to such severe shocks as airplane wheels. Indeed, even the ball bearings in such wheels have been broken in making landings, so great is the force of theimpact. The blow given to an air- plane wheel when landing is severe, and the ground over which it travels before itcomes toarestisrough. Thusa wheel to bear up under such abuse must not only be able to withstand a crushing force but it The very best and most up-to-date automobile spring device is of little permanent value, therefore, to the airplane. The new airplane wheel illustrated is said to meet all these requirements. It absorbs shocks be- fore they reach the axle and reduces bouncing toa mini- mum. Even over uneven surfaces it affords easy riding for the aviator. Thus it is possible for the airplane to start and land on rough ground. Further- more, with all violent shocks absorbed by the wheel before they are communicated to the body, the life of the airplane is noticeably lengthened and its usefulness enhanced. Drawing a ribbon over the roller makes it as good as new The two front wheels of the airplane sustain practically the entire weight and receive the roughest kind of usage The new airplane wheel which is so designed that it will absorb shocks and reduce bouncing to a minimum The Re-Inking Roller for Typewriters. It Saves the Cost of a Dozen Ribbons HEN the ribbon on your typewriter has dried you can ink it again. The inking device consists of a small roller to which the ink is fed by a sort of fountain- pen arrangement. The ink is poured in the cylinder back of the roller. A_ short padding of felt juts from the end of the cylinder on to the roller. This piece of felt not only prevents the ink leaking out but, al like a wick, it keeps the _ roller moistened. When the ribbon is run through the machine against the turning roller, it is thoroughly The felt wick feeds the ink inked. If the rib- from the holder to the roller. bons are handled carefully the de- vice will save the cost of a dozen new ones and give service indefinitely. A specially prepared ink is used. It will not smudge and it is easily absorbed, so that the type striking against the ribbon give clear cut, neat letters. 856 The Upside-Down Watch—Successor to the Wrist Watch for Soldiers HE wrist watch, which rose so high in popularity on account of the endorse- ment given it by men of the army and navy, has retired to second place in the soldiers’ favor. The reason for this is not that this style of watch proved to be less con- venient than it promised, but that bullets and bursting shrapnel which constantly threaten the exposed men are likely to strike the arm wear- mah ing the watch and drive at bits of broken glass and metal into the flesh, thus aggravating the wounds. The watch which & now holds first place ‘% (it was invented by R. A. Hempel of Berlin) is “worn suspended from the belt by a loop of leather. The loop ends in a pocket into which the watch fits, as shown in the illustration. The front surface of the pocket has a circular opening through which the face of the watch shows. A small strap encircles the watch and fastens it securely in place, buckling on the outside of the pocket. The watch hangs top-downward, but when the wearer raises it in his hand or glances down at it as it hangs from the belt, it is in just the proper position to be read. If it should happen to be shattered The watch appears upside-down to everyone but the one who is wearing it’ Popular Science Monthly Covering Steam Pipes with a Glass Lighter than Cork SPUN glass, which consists of extremely fine glass threads, is being used in Germany as an insulating material to retain the heat in steam pipes. Since it is considerably lighter even than cork, it adds less to the weight of the pipe than other insulating materi- als. Furthermore, it is not affected by vibra- tion, by high tempera- ture or by the action of water, steam or acids. It retains its pristine insulating power after long lapses of time, and can be used a second time, because of this lack of deterioration. Successful ex peri- ments reveal the fact that the admirable in- » sulating capacity of spun glass is due to the air held in the inter- stices and to the mir- ror-like surfaces of the glass, which constantly reflect the heat. The Summer Girl Carries Her Vanity Case Even Into the Surf HE feminine bathing suit hasgraduated. ~ from the ranks of the purely service- able into the class of artistic creations. Many and varied are the styles and colors which its scant breadths by a bullet the particles of glass or metal would be caught and held in the leather case so that they would do no harm. Many a fighter has had to thank the watch’ on ‘his wrist for stopping a bullet that display. But in many instances the effect of the costume is marred by the unattractive rubber cord and brass bath-house key which the bather wears around her neck. The latest addition to the up- might have necessitated the loss of an arm. The very fact that the upside- down watch is carried against a more vulnerable part of the body than is the wrist watch, makes it all the more valuable as a protective medium. It to-date suit, however, is a belt strap from which a waterproof ~bag is sus- pended. the objectionable key but jewelry and other valu- ables may be kept in safety. berized material and it is may be worn under the cartridge belt. The surf bather’s receptacle for her valuables and bath-house key fastened securely with a rust-proof clasp. In this not only” The bag is made of a rub-- ‘vr. ~. — a) ele eS ee _— = “Goins to Sea” in an Armory o2 HE making of expert ™ signalmen no_ longer begins at sea, but at our ™*%*© naval training stations and in some of our armories. In the Second Bat- talion Naval Militia, at Brooklyn, New York, young men are turned into proficient signalmen long before they are assigned to service on a battleship. The ar- mory has a signaling equipment as_ com- plete as that of a modern man-of-war. Warships are great talkers. There are flags and semaphores for carrying on con- versation “by day, Ardois lights, blink- ers, searchlights and rockets for night use, code and distress sig- nals for special pur- poses, whistles and subma- rine warning signals, and the wireless telegraph. You have seen the sig- nals sent out from the ends of the flying bridges by posts and arms that look like “‘jump- The interiors of the naval training stations are made to resemble the modern war vessel in design.and The __ semaphore the intricate fighting equipment signaling device which is found at the end of each big ship’s bridge Students of the Boys’ HighSchool, Brooklyn, N. Y., practicing with a big gun mounted in the armory Ee: < © Underwood and U nderwood, N. Y. $58 ing jacks.”’ semaphore now signals twice as fast as the best wig-wag man. When the distance is too great for the semaphore, the big red and white flag still spells out the Cubitiere (Joint messages. Signal flags, or hoists, are always used when the fleet is in battle or maneuver- ing at sea. For the flag hoists, as they are called, there are twenty-six flags of the International Code, one for each letter of the alphabet. This code is used by all navies and the merchant- men of all nations. Of course each navy has its own secret code, written in a code book, which is jeal- ously guarded. Its loss is a court-martial offense. It is weighted with lead. If a ship is captured it is thrown overboard. At night the red and white lamps of the Ar- dois are flashed. But yard-arm blinkers which signal dots and dashes in short and long dis- plays, are supplanting the Ardois because they are faster. Small search- light lanterns are now being used on the bridges of our fighting craft. One ship can lie at one entrance to the Panama Canal, and signal across Culebra Cut to another at the opposite entrance with ease. Then there are wireless and rocket signals, whistles and sub- marine signals—all in- cluded in the equipment of the armory shown. They are semaphores, made of wood or metal and operated by levers. Be- fore the semaphore was perfected orders were signaled by flags, which are still in limited use. The Epauliere (Joint Protection) Protection) Habergeon (Coat of Chain Mail) Genouillere (Joint Protection) Popular Science Monthly Helmet Mask Gorget (Throat ‘ Cuirass (Breast Plate) How our soldiers would look in the proposed French suit of mail To stop spitting in cor- ners, paint them white Should Our Soldiers Dress Like the Ancient Crusaders? (ee G its inspir- ation from the valu- able service already performed by the steel helmet, La Nature of Paris suggests that the soldier’s entire body should be encased in armor. It proposes that the sides of the head, neck and upper part of the chest be covered with a gorget, a kind of collar, and the loins with a kind of skirt, like the lower part of an habergeon, both in chain mail. A cuirass, or breastplate, of movable plates of steel would protect the chest and back, and hinged- steel elbow-pieces and knee-pieces would cover the joints. A face mask and goggles would com- plete the suit. The armor would be light enough to afford perfect freedom of action. A Substitute for the ‘*‘No Spitting’’ Placard LATHE manufac- turing shop in Brighton, Mass., has de- vised a plan to protect corners of stairs and hall- ways from the thought- less spitter, without pla- carding the walls with ‘“‘No Spitting’”’ signs. The reminder used is simply _ brilliant white paint which shows up the corner in spotless cleanliness. It has been found to be even more effective than the old signs, in spite of the fact that it carries no threat of a fine; fora man would require more than the ordinary amount of nerve or disregard for the pro- prieties to allow him to mar such whiteness. — eo ee E FE : . ? é i, 4 = a = Di ia | Popular Science Monthly 859 It’s Built Like an Egg, is =| Placing the American Eagle Barney Oldfield’s Racer On Its Perch HE ordinary racing car, N Baltimore, recently, there because of its shape, came a call for a dare-devil creates air eddies and currents that force the car to push a mass of air along in front of it and pull along another mass _in back of it by suction. It requires a certain amount of power to move these masses of air. This leaves less for the actual propulsion of the vehi- cle whose speed is’correspond- ingly decreased. Hence greater speeds than ever be- fore attained by racing auto- mobiles should be made possible by the unusual egg- shaped body which Barney Oldfield, the famous automo- bile racer, had made for him. Except for the projecting hood over the engine, Oldfield’s car is the nearest approximation to a perfect streamline body ever made. Even the pan under the engine is blended into the body in such a man- ner as to present as little surface as possible against the propulsion of the car through space. The body is completely enclosed and has none of the usual flat surfaces and angles. © Automobile makers have learned much from the aero- plane builder concerning the construction of bodies that part the air easily and so cut down wind ‘resistance. The body is made of aluminum and will be mounted on one of the cars to be seen at the racetracks this season. A pe itaeneatneinte th Placing the copper eagle at the top of the giant flagpole Wind resistance reduces speed. The air should be smoothly ‘parted by a correctly designed bulk. That is the under- lying theory of this unique racer built for Barney Oldfield to ascend the fifty-five-foot steel flagpole on the roof of an office building and place upon its top, three hundred and thirty feet and some inches above the street, a gilded eagle that would lord it over every other artificial bird in the city. Two young steeplejacks tackled the job without delay. One of them carried the copper eagle to the top of the pole and in a high wind made it fast, while the other, as shown in the illustra- tion, stationed himself mid- way up the pole to be near at hand if anything went wrong. The eagle weighs thirty pounds, it is five feet high, and the spread of its wings is ten feet. The topmost steeple- jack had to rivet it in place with two bolts, besides work- ing with his pliers and a refractory piece of sheet-iron. It wasn’t long, however, be- fore he had the eagle fastened to its permanent perch. Most old-time steeplejacks shun steel poles. They say they are treacherous, snap- ping off at the top without the slightest warning. Our Newspapers Are Wiping out Our Forests HE present demand for news print is estimated to be about tons per day. about three million cords are required annually. mand for magazine and book paper, stationery and business papers of all kinds, wrapping paper, wall paper, cardboard, fiber board, and the six thousand this demand, of woodpulp meet the de- To supply To like, four million cords more of wood pulp are needed an- nually. Because the produc- tion barely keeps pace with this consumption, the Federal Trade Commission is consider- ing means for the better dis- tribution of the product. Wooden Ships to Save England The most important principle in wood con- Veit struction discovered since Noah built the Ark } 1/ \ . By Joseph Brinker cs & New England has witnessed a rebirth of the shipbuilding industry. One thousand wooden vessels are being built in yards which have been idle since the days of the great American merchant marine crying need of Great Britain to her new ally America, as expressed re- cently by Lloyd George, in a speech to Ameficans in London. England’s fore- most statesmen realize the seriousness of the submarine problem. Submarines are being built faster than they are being sunk; merchant tonnage is being sunk fast- er than it is being built. The submarine must be conquered. England looks to America / for help. New merchant marines must be launched quickly if they are to be of any avail. Without ships, we cannot deliver the supplies that we must throw into the balance. Yankee ingenuity has risen to the occasion. While ship steel is scarce because of the great demands upon the steel industry for ammunition, rails and other kindred supplies, wood is plentiful and readily available. The problem thus resolves itself into one of providing the means S cvin ships and then more ships is the William T. Donnelly, the designer of the new wooden ship capable of carrying more than five thousand tonnage whereby wood can be utilized for ships of sufficient tonnage to make their operation commercially feasible. William T. Donnelly, a New York engineer and naval architect, has devised a construction for wooden ships capable of carrying 5,500 tons of freight, or approxi- mately twice the amount which any type of wooden ship heretofore built has beenableto carry. Hisnewdesign provides for a vessel 350 feet long, 50 feet beam and 30 feet deep. The new type of boat is almost entirely of wood. In each ship 1,500,000 board feet of southern yel- low pine take the place of 2,300 tons of steel. Why Steel Took the Place of Wood In the past, wooden ships have been driven off the seas by vessels made of steel not because the former were made of wood but because wooden ships had to Because our naval architects did 860 be made smaller. Why smaller? — + ie —- s, Center hatch Popular Science Monthly «— Side Hatches ~ TS bulkhe Old construction. Frames were made of short pieces laid out from templets and sawed to shape. Both longitudinal and lateral strength were lacking not know how to make them larger. Experience has taught us that the larger the ship the less the cost per ton carried. As long as the tonnage of the wooden ship remained small, itcould not compete with the steel vessel whose tonnage capacity was many times greater. Wooden ships could not be made larger because our naval architects did not know how to make them long and still rigid The layered or laminated sec- tions are notched into both straight sections of the frame Longitudinal I ull | Note that frame sceiling |) { eecrowned to put timber tigi! under tension for rigidity by New construction. Frame members are made from square mill timber. All parts are stressed to increase rigidity; ample provision for transverse and longitudinal strength enough to stand up under the load and the vibration of the engines. The secret of Donnelly’s success lies in the fact that he has applied the principles of steel-ship construction to the wooden vessel. The American Bureau of Shipping, which insures ships, after the fashion of Lloyds of England, has given the vessel an AI rating for fifteen years. The special characteristic of the Donnelly design is that it is made of straight pieces of stock which can be turned out at any sawmill without any tapering or special forming work. This particular characteristic is of the greatest importance at the present time. It enables eT La 4 Mu) i, Li ! | <_< © = aaa - ¢ - - = . -- =: | ae t «68 | © Int. Film Serv. The Donnelly ship is a standardized vessel made up of parts which can be duplicated in any sawmill, shipped to the nearest shipyard and put together in much the same way as the parts of a cheap automobile Popular Science Monthly tite ne el How the new wooden ship, capable of carrying five thousand five hundred tons of freight, will look when it is finished. In each ship 1,500,000 board feet of southern yellow pine made up into hundreds of such vessels to be _ built simultaneously at various plants throughout the country. This will increase our ton- nage rapidly—which is what must be ac- complished if we are to aid in circumventing the submarine. It is understood that the recently-created Shipping Board of the United States has placed its stamp of approval on the Donnelly design and that it will supervise the construction of a large number of such vessels for use in our trans-Atlantic trade. Making the Ship Rigid In construction, the Donnelly boat differs from all previous shipbuilding prac- tice in that it has a heavy wood longitudinal centerline bulkhead which extends clear from the stem to the rudder post. This bulkhead acts much as a girder in a railroad bridge and provides the greater part of the rigidity which has been lacking in previously-constructed wooden boats of the length of 350 feet. The bulkhead is made up of timbers laid one on top of the other, suitably tied together by vertical members. Another particular departure from pre- vious wooden shipbuilding practice is the manner in which the frames are made from straight mill stock with no hewn or tapered sections. Note the illustration of typical section of old construction, in which frames are shown tapered from keel to rail. As shown in the accompanying illustration of the new construction, the frames or ribs of the vessel are made up of a straight part extending across the bottom from bilge to bilge and a vertical member forming each side from the turn of the bilge to rail. The aid ‘ eae ae Electric motor { Engine room bulkhead Fuel oil Two electric tank generators i Pe: wes a +TW0 oil ‘ MI Beh ng FF _Pengines ut 5 ie ae =¥4 g sig Cargo Sa = eeseseens ecten sear seetec nes saaghos rete plant esha ; ine 7 — Collision, rem Sr The use of the center longitudinal bulkhead makes it necessary to have side instead of center hatches or openings through which the cargo is deposited in the hold. Nocargocan be shifted once it is in the hold ne ee ee ae EP, a NN e aee Ni ict al ah bi a 2 . ~ Popular Science Monthly 863 use of what corresponds with the top plate of the double-bottom in a steel ship. This timber, of slightly less size than the frame itself, is firmly bolted to the centerline keelson at the middle‘and then bent downward at each end.on a wedge-shaped block between it and the frame member below the turn of the bilge. The frame member is also bent upward slightly so that both pieces of timber are stressed under tension which gives a much greater degree of rigidity. Similarly the side member of the frame is stressed by being bent in slightly at the top and tied to the same frame on the other side by means of the upper deck beam, and a crosswise deck beam or stiffener is used in the hold to add rigidity to the whole frame. Careful Loading Is Necessary The use of the center longitudinal bulkhead makes it necessary to have’ side instead of center hatches or openings through which the cargo is deposited in the hold. » This means that no cargo can be shifted from one side of the vessel to readil eae eae ae the other after it is once in the hold. Yy prepar and e€asuy assem straig . . ie : pieces of stock will replace 2,300 tons of steel While this necessitates careful loading of the ship to give the proper trim, it offers bilge turn itself is formed of a laminated an additional advantage of providing a section strongly connected to the previous Cargo space clear of beam posts or pillars. members. All the parts are adapted to be The development of this unusual design entirely finished by machinery. of wood ship has been under way for more Another particular construction differing than three years, and it Was a mere coincl- from the method previously followed is the dence that it was practically completed just at the time of our declaration of war ( tart A ed Sauna” against Germany. Mr. Donnelly is a me- chanical engineer who learned his s ' trade as a pattern maker with a our 350 horsepower eer : “high speed oll famous printing press builder. He 7-7 Sagines_ =| ~=—s became _ a consulting engineer on age ecg + Soipacide’ rea 3 | wooden drydocks in 1898. It oa ee aes | was this experience which _— | arrmapeaeatiesee = i ead t evolved his plan of building Rae a Saas | wooden ships. Coal bunkers 500 tons capacity with 5,000 mile cruising radius Two types of ships have been ye devised, as shown in the dia- grams. Two fuel oil tanks will feed four high speed oil engines, giving a cruising radius of seven thousand miles, as shown above, or a triple expansion steam engine with a coal bunker capa- city of five hundred tons will give a cruising radius of five thousand miles as shown at right Triple expansion / Four water-tube steam engine boilers 864 Popular Science Monthly The motorcycle mounted on a platform at the side of the airplane. The cyclist is a passenger. Army and navy Officials believe it will increase the scouting efficiency of the fliers Some Lessons Learned by the Deep-Sea Divers | pertains. TS made by the British Admiralty and the United States Navy prove that deep-sea diving is feasible. It has been found — that the shorter the time a diver takes in getting to the bottom the better, because the body absorbs less nitrogen. Also, the diver must have at least one and one half cubic feet of air per minute at all depths. Lacing the legs of the diver’s suit increases his stability and permits him to come to an erect position with ease. It also lessens the dan- ger of his falling or being sud- denly blown to the surface. Adding the Motorcycle to the Usual Airplane Equipment MOTORCYCLE was recently carried on a cross-country flight over Ingle- wood and Los Angeles, California, in a fifty-horsepower tractor biplane, on a plat- form between the planes and alongside the fusilage. A motorcyclist was also carried as a passenger. Despite this extra weight, the great plane got off the ground with a run of two hundred and seventy feet and climbed to an altitude of two thousand feet and later to six thousand feet, without any apparent addition- al effort. When the flight was fin- ished members of the army and navy flying corps were unanimous in their belief that the combina- tion of airplane and motorcycle marks the beginning of a new era in military airplane equip- , ment. : In the test flight the mo- torcycle was secured with straps to the airplane in such The Fake Camera-Crank for Taking Motion Pictures HE life of the camera-man who takes the weekly news motion pictures is not always one of glory. When Mrs. Vander- rich, for instance, asks him to take a picture of her poodle when he wants per- mission to take pictures of her yacht, he finds himself between two fires. Either he must waste some precious film on the dog or he must refuse and be shown the quickest way back. One wise camera-man, how- ever, improvised a fake camera- crank for such occasions. The crank-arm fits loosely on the shaft of the film gear in the camera. When the poodle is going through his antics, the turning arm slips on the shaft, and not a foot of film isexposed although to all appearances a pic- ture is being made. On coming to the yacht, however, a flat block on the crank-arm is pressed inward. This pushes a steel pin attached a way that it could be quickly removed. The platform that held it in position was easily constructed. At one time the airplane landed because it was short of gasoline. This the motorcyclist quickly secured. The steel pin fits into a hole in the crank-shaft. When the pin is pulled out, the arm slips loosely on the shaft so that the motion-picture op- erator may go through the motions of taking a picture, to please some one, without exposing a foot of film to the thumb block into one of the holes drilled into the crank-shaft. The crank-arm is thereby locked to the shaft, so that when the crank is turned, the film gear op- erates as usual. ‘Popular Science M onthly _ Aiding the One-Eyed = Shooter to Sight as Accurately 3 ‘HE middle aged man, . accustomed all his life to shoot from one shoulder, ‘can learn to shoot from the other shoulder just about as easily as he can learn to write with his left hand. But, while men who have lost the use of the right hand learn to write with the other hand because they have to, most men, having to change shoul- ders, stop shooting instead. The eye directly back of the gun-rib is the guiding eye. If that is lost or injured, and the left eye put in command of the gun shot from the right shoulder, then the gun shoots neatly to the left of everything fired at. Unfortunately the eye back of the gun is the one to be injured if anything happens in the way of blow-ups or blow-backs. In sidling around the difficulty created by an injured right eye, it has been the practice to make a cross- eyed stock, with a lateral bend in it, so that the gun, held at the right shoulder, will line its barrels up before the left eye. This is clumsy and costly, and usually altogether ineffective. Finally an American trapshooter, H. W. Cadwallader, a profes- sional in the employ of a big cartridge com- pany, found the obvi- ous remedy. He evolved an off-set rib which is attached to the shotgun barrel and which is set off to the left just far enough to line up before the left or guiding eye with the gun at the other shoul- | der. The sole difference is that the pattern of the gun, some three feet across at effective ranges, is, say, two inches off-center. As proof of the pudding, the inventor broke 96 per A hedge of : spiny cactus, sixteen feet high in some places and five feet thick, keeps out thieves and makes an attractive wall Keeping Out Fruit Thieves with a Fence of Spiny Cactus EAR Glendale, Calif., is a fence which makes a very satisfactory guard for an orange and apricot grove. It is a cactus fence, grown by a rancher whose fruit was stolen by every one who passed along the road. He planted a large number of cactus shoots along his fence line. In about a year a spiny hedge had grown up to a height of three feet. It is now nearly six- teen feet in height and from five to six feet thick. If the barbed wire fence is dreaded by every thief, what can be said of the cactus hedge? It is practically impossible to climb through it. On each of the cactus leaves are hundreds of needle-like spines. The prick of a spine may pass un- noticed at first, but an hour later inflamma- tion and pain begin. During the blooming season of this cactus hedge, which is between the first of May and the last of July, the fence is beautiful. The spiny buds form on the edges of the leaves, generally clustering The off-center device which makes it possible to shoot fro'n the right shoulder at effective ranges while sighting with the left eye about the tips, and soon what is known as the “‘cac- tus apple’’ appears. cent of 700 clay birds fired at with this off-set rib— a good record for any man. 866 Popular Science Monthly 4 The Amount of Energy Expended in Coughing F you cough once every fifteen minutes for ten hours you expend energy equivalent to two hundred and fifty units of heat, which is equivalent to the nour- ishment contained in three eggs or two glasses of milk. So says a German who has specialized on the waste of energy in coughing. At a normal rate we expel air from the chest at the rate of four feet per second, but in violent coughing we expel it at the rate of three hundred feet a second. Thus a persistent cough not only weakens the constitution but it is a direct cause of emaciation ac- cording to the same authority. Such weighty statistics lead to a Two dial hands indicating mileage are geared up to the two rear rollers. They Make Twenty Miles an Hour but They Never Move an Inch HE fun and exercise given by a good bicycle race need no longer be ham- pered by the condition of the weather. A machine has been improvised in one of New York’s East side recreation centers upon which the race can proceed indoors, whatever the weather. The machine is made up of two sets of rollers, three rollers.in a set, on which the competing cyclists ride side by side. The two rear rollers of a set support the rear wheel of the bicycle.. When the cyclist pedals ahead, the rear rollers are turned and a belt attached to a pulley on one of them makes the front roller of the set turn also. Both wheels of a bicycle are therefore kept re- volving so that the balancing action due to motion is equiva- lent to that obtained on the open road. The progress of the race is 3 indicated by two hands that A travel over a mileage dial. Each hand is geared up with a rear roller of the machine. The exact distance that each wheel has gone is also registered. Each revolution represents half a mile, and the cyclist who first finishes the prescribed number wins. The cyclist who first succeeds in making the prescribed number of revolutions wins lever mounted on the driving wheel opens a valve and releases the exploding gas into the re- sonating sound chamber reiteration of the oft-repeated in- junction, ‘never neglect a cough.” A Good Automobile Signal Is Accident Insurance ~ automobile warning signal recently put upon the market is a whistle that is operated by the gasoline explosions in a cylinder of the engine. At critical times the full force of the cylinder explo- . sions operates the whistle. A powerful blast is produced which can be heard above all traffic noises. The device consists of an air chamber into which the stream of exploding gases from the cylinder rushes to produce the blast. A small gas-tight valve is interposed between it and the top of the cylin- der. This valve is very much like the exhaust poppet valves on the engine it self, except that it never opens to blow the whis- tle unless the driver presses the control lever for that purpose. The _ pressing of the lever on the driving wheel forces down the valve into the cylinder by means of the wire link connec- tions between the two. This allows the regu- larly exploding gasoline to escape into the whistle instead of work- ing against the engine piston. The explo- sions follow each other very rapidly. > A “Community” Power Plant for New York It sells heat and power to the ' skyscrapers of lower Manhattan ANY of the skyscrapers M now being built in New York city’s financial dis- trict will have no boilers and heating plants of their own, and several old-time office buildings will discontinue using their engine rooms as soon as a giant new steam plant is put into operation. The new plant will sell steam heat and power to any building within a convenient radius. The price for such ser- vice is said to be con- siderably less than the cost of maintaining in- dividual plants. The six stacks, three on each side of the plant, are three hun- dred and twenty-five feet high. The boilers are located in a Photos © Int. Film Serv. VP A \ "ae iM vie S 7\_Y LIAN Cia . a — - building i? one hun- Se dred ah and The six giant stacks of New York’s new steam power plant 300 feet high fifty feet or ten stories high. The plant represents an outlay of one and cne- half million dollars. It will take nine hundred tons of coal a day to heat the water in the boilers. While building the stacks New Yorkers have had the opportunity of seeing some of the most thrilling dare-devil work ever carried on by structural steel workers. On days when the wind blew a gale the workmen were often in imminent danger. They were taken up to their jobs on The men were raised to their jobs and steel hoists. These giant stacks are right brought down again by means of steel hoists at home among the skyscrapers. 867 { KE Fire Walls to Combat the Fire Menace The principle is similar to that of. the cyclone cellar or the collision bulkhead of the ocean steamer HEN the Asch building fire, in 1911, \ \/ snuffed out the lives of one hundred and forty-five girls, the newspapers in indignation demanded adequate protec- tion for factory workers. New and larger fire-escapes were placed on_ practically every building, fire drills were instituted, existing. stairways were broadened, and fireproof materials of all kinds were devised over night. Today we rest easy in the knowledge that the factory fire-hazard is at last eliminated. We are only fooling ourselves. The word “‘fire-escape,’’ as applied to the usual exterior exit from a building in time of fire, is a misnomer. It should be, in most instances, ‘‘fire-trap.’’ And our fire-drills, held with such regularity under the fire Z 2 abe ‘ ‘dada Fire in a typical New York loft building. In spite of fire laws and drills the fire escapes are inadequate, the stairways jammed and the elevators stopped 868 : prevention laws, fail utterly under emer- gency conditions. This is not due to the design of the fire-escape or the weakness in the fire drill, but to inherent defects in the design of the buildings. Architects and builders generally fail to realize that the capacity of a fire-escape or stairway is limited, and that a multi-storied building, intended to be occupied by large numbers of people on each floor, must be supplied with special means for meeting the exigencies of a rapid egress. Although the fire-drill has been made compulsory in several States, it is the dread of most factory owners. In some New York city shops the workers absolutely refuse to go out on fire escapes that are from ten to thirty stories above the street. ” When a fire drill interrupts the day’s work, the day is practically lost, because some girls among the workers become hysterical and others take several hours to get back into the spirit of their work. Of course the fire drills in the public schools have reached a high point of efficiency, but ac- cording to one prominent investi- gator who studied the fire-hazard question, there was not a single concern he visited which had de- veloped a scheme of rapid dis- missal similar to the school-drill. Mr. H. F. J. Porter, an engineer and advisory expert on fire pre- vention, who was one of the first to institute fire drills in factories to facilitate the escape of the occupants in case of fire, early saw the shortcomings of the fire drill and the inadequacy of the fire escape. In casting about for some other method of escape from fire he has pressed into service the most natural and available means at his disposal: a wall of substan- tial and fireproof construction, extending from cellar to roof, with doorways in it on each floor. nt In case of fire on one side of the spy wall, the people on that side simply pass through the doorways, close the fireproof doors and are perfect- “uy ee “mends that fire : Popular Science Monthly - ly safe from the flames whose prog- ress in that direction is arrested. The principle involved is similar to that of the cyclone cellar of the western home, or the collision bulkhead of the ocean steamer. The fire wall develops a “‘bi-sec- tional building,” offering a hori- zontal instead of a vertical escape, making the fire drill unnecessary. There is nothing new about the fire wall. It already exists in buildings everywhere, in one form or another, and its value as a fire stop to protect property has long been known. Its availability asa fire-escape has not, however, been recognized, and it is this feature which Mr. Porter has advanced as affording the only means of safe escape from fire to the occupants of crowded floors. He has shown that the idea is as applicable to department stores, schools, theaters, hotels, hospitals and resi- dences as to factories. Besides being a safe and effec- tive means of protecting life, the fire wall is equally desirable from the standpoint of preventing large property losses, and for that rea- son it is advocated by the insur- ance and underwriting interests. In one hundred and _ fifty-nine buildings, fire walls were fourfd in thirty-five, and where used and understood, engendered a feeling of se- isi b Addition curity and safety. Mr. b £5) : Porter recom- P walls be com- pulsory in every future factory building over seven stories or eighty-five feet in height which is occupied by more than fifty persons above the first floor. In no direction is the necessity for the sectional building greater than in the hospital field. It seems incredible, but it is nevertheless true, that hospitals, asy- lums, and similar institutions housing bed patients, cripples, the blind, the insane, and infants, have too few attendants to help them. Thus, in case of fire, these helpless inmates must inevitably perish. aon ] | ding = Be a. - Diagram showing how fire walls are utilized in New York city hospital buildings. Heavy lines indicate the fire walls 869° Fire in a loft building equipped with the fire wall. The occupants pass through the doors of the fire wall and are immediately out of reach of the flames In the section- alized hospital, the attendants are called from wherever they may be to the endangered i| section. Here they wheel the bed patients in their beds and assist the others the short distance neces- sary to the adjoining sections where, with a minimum of disturbance and of time, they are rendered perfectly safe. Mr. Por- ter has introduced this system in all the hospital and institutional buildings of the Department of Public Charities of New York city, and in others elsewhere. He has offered his services free through the Mayor’s Committee on Defense of New York city, to plan and supervise the sec- tionalizing of any hospital which tenders its facilities to the nation in the present crisis. = = See « ES | Addition} | | oe Popillad! Seiénée Monthly Planting Strawberries with a New Time-Saving Machine ae emiiiaesne te growers will find that a machine which sets out the plants better than it can be done by hand is a means of saving a great deal of back-breaking work. As three men and a team of horses are able to set out three acres a day with the machine, it also means that the plants may be put into the ground when weather and soil condi- tions are the most favorable. One of the men drives the team, while the other two place the plants in the ground in a furrow opened up © Amer.’Press Assoc. With their hands and elbows on the piano the deaf mutes “hear” the music through vibrations How Deaf Mutes Feel Music Through Their Lungs, Feet, and Heads EAF mutes love music. It thrills them. The accompanying illustration shows four deaf mutes receiving musical vibrations by placing their hands and elbows on the piano while the teacher plays it. The vibrations not only give sensations which enliven the body but they actually stimulate them. The parts most sensitive to vibrations are the chest, head, lungs and feet. ‘‘An exciting feeling comes up through the floor,” is the way one deaf boy describes it. ‘“Without music I would be lonesome,’’ wrote a little Italian deaf- mute. ‘It gives me a strong shock through the feet to the head,’ stated another. Others, when asked to explain their sensa- tions, said: ‘‘I feel it in my temples and in my legs,” “‘I feel it through my whole body,” and “‘Ifeel it in my chest and lungs.”’ According to teachers of deaf- vA mutes, musical instruction is more important as an educa- Mb tional factor for the deaf es child than it is for the . hearing. Of course- it is doubtful if the totally deaf child can learn to distinguish pitch or tone, and discord from harmony, in the accepted sense. But there is no question that they feel music and that it stirs their emotions. In the New York Insti- tution for the Deaf, eye rhythm, ear rhythm, body rhythm and motion rhythm are all utilized. The two men below place the plants in a furrow opened by a shoe. Water is automatically fed by a shoe of the kind used on corn- planters. An automatic trip con- nected with the wheels opens a valve, so that water escapes froma barrel and drenches the roots of the plants; two in- clined wheels then press the soil firmly about the roots and even cover the wet soil with a layer of dry dirt which prevents caking. Spaces between plants may be regulated to suit the grower. The fre- quency with which the water is allowed to escape can be finely adjusted by means of a lever. After the plants are set out, it is neces- sary for a man to go over the work, here and there removing excess dirt or plac- ing the roots deeper in the ground. The machine works best in a good seed bed, but has been used with success in sod ground. One grower of long experience succeeded in getting an average of ninety- six per cent of his plants to grow—a larger percentage by far than he was ever able to get when the work was done by hand. At best strawberry raising is a precarious undertaking. A ® planting machine such as ws the one shown here should fill a long felt want. ee a Popular Science M onthly Attaching the Phonograph to [m= the Telephone—the Latest ¢ Efficiency Device MISTAKE in that order? Was it taken over the tele- phone? And was there a dicta- phone record of it? If so the error is not likely to be chargeable to the office, for there in the com- plainant’s own voice is the record of what he said over the tele- phone. That’s the newest idea. All this is realized by means of an invention patented by Green- how Johnston, of Richmond, Va., which transfers conver- sations from the tele- phone to the phonograph. The transference of the sound waves is made through a small box which contains a num- ber of reeds inside. Transferring conver- sation from the tele- phonetothe phonograph At left: How the tele- phone sounds are ampli- fied to make a record This box is the keystone in the invention, for it amplifies the telephone sounds so that they will make an intelligible record on the phono- graph. The ordinary sounds from the telephone receiver are too weak and too befogged to produce a clear record when led to the phonograph directly. But when these same sounds are led first through the box, the reeds take up their vibrations and add _ strength to their tone. The receiver and the transmitter are both connected with the amplifying box by tubes. The phonograph is also connected with the box by a tube. wi ; Pe. J 2 =X 3 a a < a + >=. 4 = s 4 ~ Army Officers watching the maneuvers of the wooden tank. The wire-cutting blade over the front wheel is an innovation The device can take the conversation of either or both persons talking, or, if not needed, it can be easily disconnected fror the telephone. Connection can be mad with any telephone or phonograph. A Wooden Tank Shows Itself Off Before Army Officers in California N armored tractor car of the tan! variety which disclaims any relation- ship to the members of the original family which ambled across No Man’s Land, took California by surprise recently. Although it was constructed of light lumber with wooden rivets it was formidable enough in appearance to furnish the thrill for a motion-picture battle. After it had served the purpose of the motion-picture people a demonstra- tion test was held before a board of the United States army officers at Los Angeles. The pseudo tank climbed hills and worked its way over sand dunes to the edification of the army men. The formidable- looking gun which peeps out of the front turret is of wood and is as harmless as a pea- shooter. One noteworthy in- novation is the wire cutting blade carried in front directly over the wheel. “S From receiver Totransmitter Housekeeping Made Easy aN EK SASCa A grid for use over the out- door fire. It may be used either with or without the legs The latest device for keeping out flies is a sprayer filled with a solu- tion that is deadly to flies, but will not injure the finest fabrics such as are used for curtains. The smell of it, though faint, will keep away all insects en A step-saving problem was solved by this dumbwaiter. A hole was cut in the floor through which the dumbwaiter could be lowered into the cellar in order to keep food supplies in a cool place. The top of the dumb- waiter fits over the hole like a trap-door as shown at right above An old tooth-paste tube unfolded, thor- oughly cleaned and polished and rolled again over a round object, makes a ser- viceable icing-gun. Any shaped outlet hole can be easily made in the top A simple device for removing the pit from a peach without crush- ing the fruit or staining the hand with juice A metal strainer is attached to the side of the preserving _ ket- tle to hold the spoon in place Ben vCr Cree, Housékeépings Madé Easy A dovetail groove cut in the under- side of any picture rail to take a spe- cially formed hook for hanging pictures without marring or disfiguring the molding in the slightest degree a A novel orange bowl made in the form of a sphere. It is nine inch- €s in diameter and fin- ished in white with colored flowers A self-server consisting of a small disk or table so constructed that it Thumb revolves on a_ short button CON pedestal. It stands in : the center of a table, .within convenient reach Compression spring A salad dressing con- tainer-in which a ro- tating part with wings is driven by hand or motor power to mix the ingredients. It re- sembles a coffee pot e Spring mot Winding key With the advent of the electrical heat- ing teapot almost every kind of mod- em cooking utensil is self-contained Flies naturally collect at the upper part of a door and enter there when the door is opened. With the two-part screen door children can pass out and in without giving the flies the slight- est chance to enter the house 43 we The Wonders of Coal Tar : No branch of industrial chemistry yields more widely appli- cable and varying products than the distillation of coal By George M. Oaks F you have ever tried to run a furnace I you know that coal gives off gas when heated. Yes, and you probably know that most of our illuminating gas comes from coal in that way. In by-product coke ovens the coal is heated in closed vessels so that the coal is distilled and not burnt up. But did you realize that this,is the basic operation leading to hundreds of common, everyday products: tar, coke, lampblack, creosote, carbolic acid, naphtha,’ sal-am- moniac, ammonia, varnish, photographic materials, explosives, drugs, mineral van- illa, dyes and many others? Coal, when heated, is chemically dis- membered to form several new substances which can be recombined or united with other substances to form new products. A toy house, made out of a child’s building blocks, can be taken apart and a new house built, either out of the same blocks or by adding others. This process, it should be borne in mind, is a mechanical one, and only serves to illustrate in a simple way the distillation of coal, which is a chemical process. Synthesis, or the process of building up new products from simpler ones, is best — illustrated in making dyes. There are now so many shades of the same color that we Creosote a Middle Photo-Dyes S Chinolin || HeavyOil Coal is a precious mineral. Its value can be better appreciated by noting some of the products such as dyes, explosives, drugs and perfumes, obtained directly or indirectly from its distillation 874 en Oe ee fF eee ee eet Ride) 4s i A a 1ti ilanie : j ; : cally worked out. Z Popular Science Monthly have no little trouble in trying to match colors, whether silks or house paints; not because the chemist cannot make the same shade twice. Indeed the synthesis of dyes is like the multiplication table for reli- ability. It always gives the same result. The Modern Chemist Experi- ments on Paper _ Instead of messing around in a laboratory with a dozen or more retorts, a lot of stains and a dirty, smudgy atmosphere, the chemist of today simply sits at his desk, far away from the choking acid fumes of his laboratory, and figures out on a sheet of paper the colors-he wishes to produce. He knows that certain in- gredients will yield certain results and pro- ceeds to combine them in such a way as to build up what he wants before he ever carries out the actual chemi- cal reactions theoreti- Such a_ procedure forms a remarkable contrast with the laborious experi- menting which led to the discovery of mauve, the first coal tar dye, by Perkin, in 1856. He was an en- thusiastic young English chemist who took a notion to build up quinine from simpler chemicals. He chose a college Easter vacation for his research work and labored day and night to obtain his ends. But quinine did not result; only a dingy dark precipitate was formed. Perkin was disgusted. The stuff would not even dissolve in water. He tried alcohol. To his astonishment and delight, a most beautiful violet color was | ® Plated with copper Le fromcan of peas produced which dyed silk a magnificent purple. Though only eighteen years of age, Perkin was old enough to realize the vast commercial possibilities of this discovery. Within three years the women of England had lost all sense of reason over the new oo oe te Professor D. R. Hodgdon dyed this doll’s brightly- colored clothes with coal tar coloring-matter which he obtained from cheap, poisonous candy 875 color. Punch made the following comment: “Lovely woman is just now afflicted with a malady which apparently is spreading to so serious an extent that it is high time to consider by what means it may be checked. . . . One of the first symptoms by which the malady declares itself consists in the eruption of a measly rash of ribbons about the head and neck of the person who has caught it. The erup- tion, which is of a mauve color, soon ‘spreads, until, in many cases, the suf- ferer becomes com- pletely covered with ey Hair fastened with glue poisonous dye from candy Waist dyed with coloring matter from lollypops In speaking of finished dyes, we have jumped from coal clean over the _ thou- sand and one in- tervening pro- cesses, to the usable product. After coal is first split up, the next most important way station on Skirt dyed another’ -color also from lollypops A poisonous lollypop our trip from coal to the outskirts of the whole in- Dyed vivid dustry, is coal reen froma tar. cents worth of . Jollypops Coal tar is the most disagree- able, foul-smell- ing, black sticky liquid you ever saw. When gas is distilled coal tar condenses in the pipes. For years every gas works had to contend with it as an extremely bothersome by-product. It was worse than waste, for vegetation died wherever it was spilled; streams were polluted if it was allowed to drain into them. It is a com- bination of liquid and solid substances consisting mainly of hydrocarbons, which are complex compounds of hydrogen and carbon. The separation of these constitu- ents into such products as paraffin, naph- tha, benzene, cyanogen and the like, is now an industry netting millions of dollars annually. Coal tar is now practically dis- tilled in order to obtain these products. Fractional distillation is the gradual rais- ing of the temperature, driving off the % “o~Shoe lined with Shellac from peach pits ‘876 more volatile gases first and the heavy ones afterward. This treatment of coal tar is combined with alternate treatment by certain chemicals, commonly referred to as reagents. These reagents consist of dilute caustic soda, dilute acid and con- centrated sulphuric acid. When distilled up to 252 deg. Fahr., ben- zene, more frequently referred to as benzol, is obtained. It is the first to pass over. By further distillation, up to 306 deg. Fahr., sol- vent and burning- naphtha are also driven ont: >tall further heat- ing from 414 deg. to 486 deg. Fahr., results in the formation of creosote and other oils, referred to as the heavy oils. Beyond these are obtained anthracene oil and anthracene, both used in making dyes. Other products are lampblack, used in making printer’s ink; pitch, employed for roofing, road-building, water-proofing; and coke, used instead of coal for obtaining intense heat without smoke, especially in blast furnaces. In 1916, 54,200,000 tons of coke were manufactured in the United States. A beehive coke oven. The coal is admitted at the top and the coke removed through the side openings. By this crude method, the tar and ammonia are entirely wasted, passing off into the air ‘Popular Science Monthly Benzol Obtained from Gas or Tar In the case of coke oven gas, benzene (or benzol) is obtained by a direct recovery method. The recovery of benzol is limited almost entirely to the coke oven plant and to the tar distiller. The chart on page 874 shows how benzol can be obtained directly from raw gas or indirectly from the raw tar. During the distillation of tar the so- called light, middle and heavy oils which come off give us the first nine dye‘‘crudes,”’ such as ben- zol, toluol, xylol, naph- thalene. By addition and subtraction of various chemicals, and by cer- tain chemical © changes, these crudes make up the 300 dye “‘inter- mediates,’’ such as phenol, aniline, cresol, etc. . These, by further addition and sub- traction, make the 1200 different coal tar derivative dyes. . ’ These colors range from black up through the rainbow colors and other shades, such as the browns and grays. In fact, to tell the difference between two similar shades is like splitting hairs. In the chart, page 879, I have shown only the production of basic reds. A battery of by-product ovens. ovens and the lower one for ramming the-coke out on the farther side. with a clay-packed lid. Half the gas formed is consumed in heating the coal. Observe two trams, the upper one for depositing coal in the The ovens are sealed The remainder, as well as the tar and ammonia, is conducted away through pipe lines to the receiving tanks Popular Science Monthly S77 Crude carbolic acid plant. Phenols, cresols, xylols are washed with caustic soda. The phenol is freed from soda with acids Coal tar dyes lend themselves so easily to coloring all substances capable of being colored that they are only too frequently abused. The illustration on page 875 shows a doll made by Prof. D. R. Hodgdon, who wished to call attention to the deleteri- ous use of aniline dyes in candy. Miss F. P. Sweets (Fraudulent Poisonous) con- tains poisons extracted from cheap confec- tions, such as lollypops and all-day-suckers. The glue which holds her hair on, the brilliant pink dress and green stockings, the copper on her knife blade, and the lampblack on _ her From the refining stills, 71 and 72, the phenol passes into the cooling tanks above, and then into the large receivers below thetic dyes, now prepared from coal tar. An average tar yields seventy per cent of pitch and only six per cent of materials useful in making dyes. In the United States, ninety per cent of the tar goes to make better roads and better roofs, and also for the manufacture of creosote oil, naphthalene and other profitable products. After leaving coal tar, the next station is benzol. Benzol is an extremely inflamma- ble, colorless liquid obtained as previously stated, by the destructive distillation of coal tar. It is the basic product for the manufacture of ani- shiny shoes are all right in their place, but surely that place is not a child’s stomach. Although an Eng- lishman discovered the first coal tar dye, the German and not the English developed his dis- covery commercial- ly. They succeeded so well that they destroyed the nat- ural dye industry. Then Indiasuddenly found that her in- digo plantations were ruined. So cochineal, and min- eral dyes, like Prus- sian blueand chrome line colors and also cheap varnishes. It is used for many other purposes, chief among them being the manufacture of explosives. Before the Euro- pean war, the nor- mal production of benzol in the United States was approxi- mately 3,000,000 gallons annually. Since the war, many steel companies, and yellow, have been rapidly giving place to the modern syn- Huge benzol stills. right is an agitator in which benzol is washed with sulphuric acid before entering the stills other similar indus- tries, which could recover benzol from their other opera- tions, have been do- ing so. Result—in 1916, upwards of 15,000,000 gallons “ome (amyiae 3 nal were produced. If every man, woman Popular Science M onthly” Interior of a naphthalene subliming house. The vapor passes into this chamber and crystallizes on the ceiling and in the air At the right are shown tanks in which crude naphthalene crystallizes out of light oil. After several days, the oil is drained off and child in the United States were to use a pint of last year’s benzene for cleaning purposes, there would still be left enough to furnish each inhabitant of the District of Columbia with another pint. This enor- mous increase has been more than offset by the simultaneous increase in the demand for explosives. Ancient signs and wonders pale when we consider the stupendous importance of coal tar. The indigo annually consumed in the United States would buy army rifles for 62,500 United States troops. The sulphur black used in one vear weighs as much as two ordinary passenger trains of ten cars each, including the locomotives. The tech- nical name for sulphur black is di-nitro- oxy-di-phenyl-amine. Think of the millions of: pairs of ordinary black socks dyed that color! More than twice as much naphthalene is being used as before the war. It has largely taken the place of camphor. At present it is being used, not so much for exterminating moths, as for killing men, since this important coal tar “intermediate” is employed largely in the manufacture of explosives. In 1916, 3,500 tons were pro- duced in the United States. It is estimated that in 1917 over 300,000,- 000 gallons of tar, or 3,000,000,000 pounds ~ will be used. Of this, 1,800,000,000 pounds will become pitch, leaving 1,200,000,000 pounds for dyes, medicines, disinfectants, explosives and other similar products. Before the war, aniline oil, which is de- rived from benzol, and which is so impor- tant in making aniline colors, was not manufactured to any extent in the United States. It was furnished almost exclusively by Germany and England, the prices and conditions being beyond our control. In 1914, imports dropped suddenly. The de- mand for aniline oil became acute. Even yet this precious chemical is not turned out a Pees. Popular Science Monthly in sufficient quantity to meet our demand entirely, though it will be if the present increase in production continues. Aniline ‘Dyes Valuable in Bacteriology Aside from the common uses of aniline dyes may be noted the vast requirements of bacteriology. This science has made incredible progress since the staining of microscopic preparations with aniline dyes has enabled scientists to distinguish and recognize germs. Thus typhoid, cholera, tuberculosis, and other baffling diseases have been defined and studied. _ The most familiar explosive in the minds of mortals today is T. N. T. (tri - nitro - toluene) —a coal tar prod- uct. It is an oil belonging to the benzol group, and obtained by the distillation of pri- mary oil. It is the result of com- bining nitric acid with pure toluene. When being poured into shells, T. N. T. like thick, syrupy chocolate. Carbolic Acid Has Many Uses Phenol (carbolic acid) is consumed in the United States at the annual rate of from eight to ten million pounds. The pro- duction of certain explosives depends on phenol. It is used in making picric acid "(Tannin Dye) (Tannin and Acid Dye} looks Whole trainloads of wood to be cre- osoted are run into long cylinders and allowed to soak for several days A square yard of wood block pave- ment contains 45.36 pints of creosote oil and also aniline colors. The great value of phenol was still further heightened by the invention, by Dr. L. H. Baekeland, of a peculiar resinous substance which can be used in place of hard rubber. It seems like a magician’s trick to combine two such strong-smelling liquids as carbolic acid and formalin to Thio oh (Vat Dye) ©) (=) {Direct Tannin Dye) (Tannin Dye) oe Benzo] = Fuchsin dan asaya) Cotton Dye) e) Bel rane (a) (ae | Benzidin | | Mauvein | Dye Ae I | Azo|Dye L | Azo Benzo! | | Anitin | PNitranilin| | | 7idin and P |Alizarin(RED) ; ie yj c = J ee idj iW; | Nitro Benzol — OUUeNitroTeunl [%fidin and | |capheyiemi) | Phtal Acid | aa@Menttiol [antmracinon| | faa at Benzol | _Toluo a Xylol | Lsptain|[Napttbatin eordey er [anthracine | LIGHT OIL [meprum ox] This chart will give some idea of the formation of various red dyes. It may be noted that _ Most of these colors start from light oil; also that certain shades may be formed in two ways 880 form a solid, transparent, amber-like sub- stance, odorless, heat-resisting, a non-con- ductor of electricity, impervious to most acids, oils and steam, and insoluble in all known solvents. This substance is used for insulating, es- pecially in automobile ignition work, since it does not burn or soften when heated. It also makes beautiful parasol handles, fountain pens, buttons and numerous other useful articles. The chemical name for this jack-of-all-trades is oxy-benzyl-methylen- elycol-anhy- drite. Another sub- stance which tracesjits origin back to the shining lump of coal is ammo- nia, important in chemical manufacture, in refrigera- tion, asasource of nitric acid and in fertil- izers. Inks of all sorts are de- rivedindirectly from coal tar. Among them are printing inks, ranging from cheap newspaper black, made from lamp- black} to thick heavy Popular Science Monthly Artificial Sunlight for Bald Heads: HAT causes sunburn? Not the heat of the sun, but the light alone. It is not the light that you can see but the light that you cannot see—what the physicist calls ultra-violet radiation. Just as there are sounds that we cannot hear, so there is light that we cannot see: If our eyes were only differently constituted we might see ultra-violet radiations. These ultra-violet radiations have very remarkable curative prop- erties. They kill germs, and they penetrate the skin suffi- ciently to set up a wonder- fully stimulat- ing action. Hence, special lamps have been con- structed which radiate — ultra- violet light and which are used for the treat- ment of skin diseases in par- ticular. Since bald- ness is a skin disease, it fol- lows that phy- sicians have been treating it with ultra-vio- paste used in let radiations. copperplate printing. Col- Dr. Ludwig Oulmann, the New York skin specialist, treating a case of baldness with ultra-violet radiations. The lamp used may be regarded as a very intense The results are often astonish- ored printing and writing fluids as well as typewriter ribbons and copying inks are also made. Vanillin, which has the flavor of the vanilla bean, is obtained from benzene. Creosote is used as a wood preservative and medicine. Benzaldehyde is the base of many exquisite perfumes. Benzoic acid is used as a food preservative and sac- charin is a substitute for sugar, used by diabetic patients. Phenacetine is a drug used in controlling fever, and salicylic acid becomes asperin, used for all sorts of aches and pains. miniature sun. Twenty minutes’ exposure sets up a stimulating action which induces the hair to grow ing. Many a head as free from hair as an egg has been exposed for twenty minutes, at intervals of three weeks, with the result that in about two months down begins to sprout. There are cases enough to show that ultra-violet radiations restore prema- turely gray hair to its natural color. A bald head exposed to ultra-violet radiations appears in twenty-four to forty- eight hours as if it has been sunburned. In reality, it has—by an artificial sun of great intensity. The skin peels and tans. Nature is encouraged, as it were, to remove the dead matter and to create new hair. Pere a eee —— : 3 | | Y 7 cident to the re- moval of wheels and of this kind. of the chassis, Ploughing the Farm by Automobile _ The latest tractor attachment converts the Ford pleasure car into a motor-operated farm implement with push-button rapidity to a locked in place. : IFFERING from all other forms of D tractor attachments to be applied to the Ford car for cultivating small farms, that shown in the accompanying illustrations does not require the removal of a single part of the original passenger car. The entire apparatus can be attached in a few minutes and detached in less time. The great advantage of a device of this kind is that its cost is reasonable enough ‘to bring it within the reach of the small farmer who has need of a tractor for only a small part of each year. Besides, it enables him to use his passenger car for either business or pleasure and without any long delays in- various parts of the driving mechanism, as in most devices The device is made in two halves, which are simply slipped over the rear end The steel wheels of the tractor fit over the rear wheels and tires of the Ford automobile and are This gives sufficient stability to pull any light agricultural-implement he wheels and all, and then bolted together at front and rear. This gives sufficient sta- bility to pull farm wagons as trailers, a plow, harrow, cutter, binder or in fact any form of light agricultural implement. The two steel wheels of the device have grip treads, each wheel carried on a short stub axle driven by chains and sprockets from a notched axle into which lugs placed on the hub of the Ford wheel are slipped. The tractor wheels are supported on two side frames bent inward at the front and joined to a U-bolt on the Ford front axle and tied together at the rear by a cross- wise bar aft of the regular Ford touring or roadster body. The two halves of the device are slipped into place from the sides and locked into position. To restore the oe car to its origi- Diagram showing how the two parts of the tractor device fasten over the wheels of the car h nal appearance | BI: and service it is only necessary to loosen the bolts and remove the steel wheels. 881 882 Protecting Canal Zone Buildings with an Oil Moat for Insects N the Panama Canal Zone ants, lizards, snakes and creeping insects are so numerous and so pestiferous that it is difficult to keep them from climbing up foundation pillars and invading houses. Hence concrete gut- ters are provided for all posts. Of course, the ants can crawl up the concrete as freely as they can up wood, but when they reach the land- ing platform of the gutter they find a miniature lake of oil-insecticide awaiting them. They never get be- yond this little moat. - To prevent the fre- quent rains from running into the insecticide, a bungalow top, also of concrete, forms a sheltering roof for the gutter. Enveloping Trees in Freezers to Study Temperature Effects CONTRIVANCE designed to freeze whole trees has been constructed at the Utah Agricultural College, Logan, Utah, to aid in experimental work intended to discover, under actual orchard condi- tions, the frost danger point: .The contrivance is very similar in princi- GALVANIZED IRON. TANK Dh | SELF-REGISTERING Sot THERMOMETER - JNNER WALL. SALTED ICE LID ON LID-\ ~~ + ~ THERMOGRAPH =) SALTED ICE PACKING BETWEEN WALLS AIR STIRRED By ELECTRIC FAN DIVIDED PLANK BASB The tank is double-walled, with a four-inch space between walls. In this space snow and ice are packed just as in a cream freezer Popular Science M onthly | ple to the old fashioned ice-cream freezer. It consists of a huge galvanized iron tank, large enough to enclose an entire tree.. This tank is divided into halves and each half is fastened to a plank base, so con- structed that a half can be placed on either side of the tree to be frozen, and the two parts drawn. to- gether, completely enclosing the tree. * The tank is double walled, with a four-inch space between the walls. A large lid covers the tank and rests on the inner wall. Ice and salt are packed in between the walls and over the lid. The temperature in- side is regulated by pumping in cold or warm air, and the air inside is kept stirred by an elec- trically driven fan. Four self-registering Weather Bureau thermometers and a ther- mograph, hung from different branches of the tree, keep an accurate record of the temperature within the tank. The resistance of buds to frost can be accurately determined by this method and data collected that will tell when smudge pots or other artificial means of orchard heating should be used to save the fruit crop. ’ The tree is not injured by the process, since care is taken and constant watch is kept to prevent the danger point from being reached. The insecti- cide in the gutter is pro- tected from rain by a cement roof Each of the two sections of the tank is fastened to a plank base. These are drawn together and a large lid covers both halves when joined — Popular Science Monthly When the gourd blossom has faded the bottle should be pushed gently over the young fruit and left there The Gourd in the Bottle. Did It Get There? OST people would be sorely puz- zled if they were asked to explain how the gourd comes to be in the bottle shown in the photograph. It is far too _large to pass upwards through the neck, and, obviously, it cannot have been pushed downwards. The explanation of the mys- tery is simple enough. The gourd is grown in the bottle. The trick is easy if directions are followed. In the first place, the gourd must be properly set before the bottle is placed over it. As soon as the flower is faded the operation may be started. Take the bottle and push it gently over the fruit, taking care not to damage it in any way. Even though thegourd is enclosed in the bottle the growth is not affected in the least. Indeed in a very few days the fruit has developed so much that it cannot be re- moved from the bottle unless the jar is broken. When the gourd has grown to a sufficiently large size it may be cut from the stem, and it is then ready for exhibition. After a while the fruit dries, in which state it will keep for an indefinite time. The same principle can be ap- plied to cucumbers, melons, pumpkins and squashes. The only precaution neces- Sary is to prevent the fruit from becoming “pot-bound.’”’ The stem should be cut as soon as the glass is well filled. How strain under The net will resist strong pulls but will collapse and release the damaging 883 The rays of the sun through the glass hasten the development. The central picture shows the full-grown gourd Catching Minnows for Bait in a Basket-Net ERHAPS the greatest difficulty that the amateur fisherman encounters on his expeditions. is the securing of live bait. But if he has included in his equipment a basket-net like the one in the accompany- ing illustration he can catch minnows and small fish in any stream. The frame of the net is made from six tempered spring steel rods. To this the netting is attached with rust- proof ring-clips. In the center of the netting is the bait pocket, in which bread, meat or other bait is placed to attract the minnows. When the net is lifted, the weight of the contents causes it to “bag,” so that the minnows will not escape over the sides. When the net snags or when, for some other reason, it is sub- jected to extraordinary strain, the six tempered steel rods bend in- ward and downward until all but one of the rings by which the net is attached to the frame slip out of the hooks. This collapsing of the frame frees the net from the snag and releases’ the strain. The in- ventor claims, however, that the net will not collapse except under extraordinary strain, which if resisted would damage the net. It folds up into a compact little bundle which is scarcely noticeable among the fisherman’s ‘“‘traps.”’ snags A Sunken Ship That Earned a Fortune How the Walkiire was scuttled, bought for $29,000, raised and sold for $825,000 The vessel was only slightly: dasisged, so rages cutee epee her ncnnnall and sunk her to prevent further attack. Only her two masts, stack and flying bridge remained visible above water HE German freighter Walkure was loading phosphate rock at the Island of Makatua when the war broke out; then she was captured by the French gunboat Zelée and taken into the harbor of Papeete, Tahiti. Later on the two German warships (the Gneisenau and Scharnhorst) appeared at Papeete, sank the Zelée, wrecked the town, and punctured the -Walkure above waterline with a few small shells. The French decided to pre- vent further damage in later attacks on the Walkiire by opening her seacocks. She sank in fifty-four feet of water. The Walkure is built like some old French war vessels and some Scandinavian freighters. Her sides TIF SIDE OF COFFERDAM rise out of BEAMS OF COFFER DAM the water TURRET DECK for about STEEL BULWARKS twelve feet, HARBOR DECK Call F<°V-:e How the cof- ‘18T POSITION Because she was thus built she was salved in a novel way. She is a single-screw steel vessel, 350 feet long, 49 feet beam, and 24 feet depth. Her gross tonnage is 3,836; net 2,403; dead weight capacity, 6,700. She has triple ex- pansion engines with an indicated horse- power of 1,800. Her bunker capacity is 1,300 tons. Her speed on trial trip was 10.5 knots. At the time the vessel met her fate, — she was 3,670 miles from San Francisco and was sunk about 300 feet from shore, resting on a sloping bottom with a slight list and with some ten feet of water over — her turret deck forward and about thirty feet aft. MA = stack and flying visible. For squarely inward a distance of ten feet, forming what is ferdam was attached to the ship and how the tow boat worked nearly a year she Kid, lay thus. TOW BOAT Eventually she was known as the “harbor. deck,’”’ then rise some eight feet to the main or turret deck. put up for sale by a French prize court and was purchased by Mr. John A. Hooper of San Only her — ‘= two masts, — bridge re-— mained is Ne al iy ‘she would rise of Popular Science Monthly Francisco for less than $29,000. Her original cost was $210,438.00. Mr. Hooper is a lumberman and not an engineer. _ Nevertheless, it was he who devised a plan for raising her. From photo- graphs of her, maps and other data, he decided that if all 885 action Worthington pump and ;two pul- someters. . . Divers were sent down to patch up the Walkure. Then the first 18-foot section of the cofferdam, constructed on shore, was lowered into place. The cofferdam was constructed of 2-, the shell holes were stopped, if her sides were ex- tended upward until they pro- truded out of the water, and if the water were then pumped out of her hold and out of the extension top, her own accord. Why? _ Because the volume of 3- and 4-in. _ planks, the thick- ness increasing with the depth of immersion. These were bolted and nailed to the joists, the entire construction re-. sembling a huge water-tight rec- tangular box with- out top or bottom. Resistance against the exte- water displaced by the extension form outweighed the force tending to buoy her up, and when removed left no alternative but for the vessel to float. The form, or cofferdam, as that kind of structure is known, was built to displace 4,500 tons of water. There was assembled in San Francisco and sent to Papeete the material for a wooden cofferdam 307 feet by 14 feet in height forward and 32 feet aft, plus an additional 25-foot section in the form of a V and also 32 feet high, to encompass the stern. The material assembled included some 600 tons of tongue-and-groove planks, beams and joists, 13 tons of structural iron, chains, hangers, pipes, etc., four direct connected centrifugal pumps, one double- The Walkiire rose to the surface like a cork as the water was pumped out of the cofferdam rior crushing force was secured -by use of transverse beams 14 by 14 in., reinforced by longi- tudinal supports 6 x 8 and 8 x I0 in., tying together the different sections. Next the water was pumped out. When the vessel floated a little she was towed a little nearer shore. The first movement of 125 feet was followed by a second of 146 feet on the following day. Pumping was then stopped and five days spent in sawing away the elevated portions of the cofferdam in order to provide stability and remove weight and _ topheaviness. One day later the vessel was afloat on her own bottom and the process of cleaning up was begun. Four weeks were spent in getting the _ One of the shell holes made in the Walkiire’s hull after she was captured by the French How the big shell hole shown at the left was plugged up before the pumping began 886 vessel ready for sea, her engines and equip- ment being found in very good condition. The two thousand tons of phosphate in her hold were left in place. Her cargo of 1,300 tons of coal was used on the trip to San Francisco. Before departing the vessel was christened Republic, and given American registry. When she reached San Francisco the ship was thor- Popular Science Monthly der from the inside of the watch. The moving inward of the plunger will have also moved the cable, so that the camera- shutter is now set for the picture. After this adjustment, the watch can be set to trip the plunger with any period of time not exceeding forty-five minutes. During this interval, in which you are get- ting into position in front of the camera, the spring-latch oughly over- hauled and re- paired ata cost, including the salvage, of $255- - 000. Yet such was the scarcity of ships that she soon paid all expenses in- curred. On one trip alone she netted $360,000. She was. finally will be gradu- ally pressed downby alever: This lever is slowly turned by a pin on the minute-hand gear. It is pro- cam at its end. If the watch has been ad- justed for forty- five minutes, sold for the sum of $825,000. A Camera Timing-Release Which Enables You to Photograph Yourself UMEROUS methods, electric and otherwise, have been devised to enable a person to photograph himself. Some have proved to be successful, but they are usually tedious and difficult processes in which there is little certainty of success. Few equal in simplicity a method brought out by Ellis E. Bjorling, of Salt Lake City, Utah. The entire mechanism con- sists of a modified watch which can be carried about in the pocket. After the camera has been placed in posi- tion, the watch is set for the time it takes you to get into place, when the picture will be snapped immediately. The watch has a moving plunger mounted in a small cylinder at its side. A flexible cable attached to the end of the plunger leads to the shutter-release on the camera. When the plunger is pressed inward to- wards the end of its cylinder, it compresses a spring. The plunger is held at the end of the cylinder by a spring-latch which projects into the cylin- The The cofferdam after it had been -lowered in place. thickness of the planks increased with the depth of immersion plunger with the shutter is pressed in against the spring by the turning of the watch after three quarters of an hour the. cam will have pressed the spring in from the cylinder. The plunger will be tripped and it will jump back, pulling the cable along with it. This operates the shutter. Ten Thousand Medical Officers Are Needed for a Million-Man Army HERE are about one hundred and fifteen thousand physicians in the United States to care for the civil population and provide medical of- ficers for the Army and Navy. In the event of an army of one million men being called to the colors, seven thousand medical officers, or about six per cent of the physi- cians who are in theactual practice of their profes- sion, will be needed at once, and three thousand will later be needed for emergencies. This means that ten thousand phy- sicians will have to be entirely detached from their home practice. It will require seven hundred others a year to replace losses. The connected Ley ne a ee ee a a a Pee vided with a. eee Popular Science Monthly A Combined Automobile Spring and Shock Absorber CANADIAN, Henry Dixon, has invented a device which combines the functions of an ordinary automobile spring and a shock absorber. The same degree of elasticity may be main- tained between the lightest and heaviest loads in order to reduce the sudden bound and rebound so uncomfortable to the passen- gers of a car. The apparatus consists of one vertical air cylinder and piston mounted on a yoke, at the bot- tom of which are pivoted two inclined spring cylinders. These in turn are connected with two other oppositely inclined cylin- ders pivoted to a top yoke and with two other similar horizontal spring cylinders spaced on either side of the vertical air cylinder. Each of the cylinders has a piston, that in the air cylinder being provided with a ball valve by which air may pass from one side to the other, and those in the spring cylinders -with washers at the ends which serve to compress the springs under action. The device is inserted between the vehicle frame and each of the springs. When subjected to an excess load or to concussion, as when the vehicle passes over 887 eee Ge. oa Sear abet ; rf : . : ; : : The switchboard and operators were raised by easy stages to the floor above and not a call was missed. This was made possible by lengthening the switchboard cable ruts or car tracks, the four inclined spring cylinders straighten out in the manner of a toggle and exert great endwise pressure, to compress the springs and increase their nat- ural force in the ratio of their compression. This compression is retarded, however, by the resist- ance of the air in the center vertical cylinder and by the springs in the two horizontal cyl- inders. The return of the cylinders to their normal position is ef- fected by a gradually diminishing force, this Spring “~~ Cylinder Cylinder J Moving a Telephone Switchboard Without Interrupting the Service TELEPHONE company at West Palm Beach, Florida, recently added a frame Air ~ "4 sy &, a action tending to reduce sudden bounds and re- bounds of the body. In this combined automobile spring and shock absorber the same degree of elasticity is maintained between the lightest and heaviest loads floor to its building and raised the operating switchboard one flight up into the new addition. The switchboard was moved to a temporary platform, to which pow- erful chain falls were attached. A half dozen rafters of the new floor had not been placed in position, so that the platform could be raised through that space. During the movement the three telephone girls continued their work unconcerned, an- swering calls and asking for numbers as_ usual. 888 ee “Sweeping” out a joint of plumbing with the new flexible wire device A Pipe-Cleaning Wire Which Worms Its Way Around Bends ROUBLE with drain pipes which continually clog up can very easily be done away with by the use of a steel cable devised by Jay H. Woolhiser, a plumber of Elmhurst, Long Island. Unlike the straight steel cables which cannot be pushed around a sharp bend, his wire can wind around the worst of them, cleaning out the waste while doing Seseet Science Monthly What One Gallon of Gasoline Might Be Made to Do HE power of gasoline is generally rated by the distance it will propel an auto- mobile. But the same energy, if directed ~ to other and more varied purposes, will milk three hundred cows, bale four tons of hay, mix thirty-five cubic yards of cement, plow three-fifths of an acre of ground, or it will generate enough electricity to light a large farmhouse for thirty hours. How to Take a Drink and Eat While You Are Fishing HE fisherman need not lose any time, from his sport in order to eat, but may have his hands free for attending . to his needs if he is equipped with the new fishing harness invented by Kenton Drinkard, Beaumont, Texas. This harness supports the fishing pole in the proper position for the line to make a catch, and the fisherman need ‘not hold his arms in one position until they are cramped and aching while he is waiting for a fish to find his bait. The device includes a body belt having a socket which receives the butt of the fishing pole. A second socket on the belt supports. a bracket arm which extends part way out under the pole and in turn provides a support or rest for it. A body strap and chain attached to this brace, affords all the additional support necessary. Equipped with this device the fisherman may en- joy his fishing interruptedly. so. The wire is made of thin, but very elastic steel. This is wound around in small loops placed very close together. The end of the wire is slightly bent, and this end is slanted away from the direction of the pipe bend. When the wire reaches the bend it therefore catches. The wire is pressed down into the pipe a little further, and is then suddenly turned. The wire end is at once released and the wire springs up into the bend. When the waste which is clog- ging the pipe is reached, the wire is kept turning. The bend of the wire keeps the end swinging around in a circle. .It thus wipes around the whole interior of the pipe. A belt fastened around the body is provided with a socket into which the pole fits, leaving the hands free Tn ee bila os ven ; i ag) ee ee ’ The contortions are ‘Toy Clowns That Perform Acrobatic Feats HE inventors of toys today are at their wits’ end to devise toys of excessive activity and laugh-producing antics at the behest of the up-to-date youngster. The most effective of these toys are usually the sim- plest in principle. The illustration shows an exces- sively active clown, or two of them, suspended from a pulley, over which they may be made to dance and perform any number of feats. The figures are flat, but with various indenta- tions and angles, so | that they are capable of assuming many ridiculous poses, in- terlocking occasion- ally, and balancing one another in ap- proved clown style. kept up just as long as the string which controls their action is manipulated. The inventor of the daring acrobais is Henry A. Hart, of Flushing, New York. Why Do Rifle and Shotgun Barrels Burst? LTHOUGH shotguns and rifles are tested with loads which give pres- sures far above those produced by ordinary ammunition, swollen or burst gun barrels are not uncommon. The cause is either attributed to defective ammunition or to an obstruction in the bore, such as snow or dirt. The pressure of the powder gases themselves are not to blame, for investiga- tion has proved that the swelling or rupture is caused by the compression of the air between the bullet and the obstruction. Popular Science Monthly The animated clown assumes ridiculous poses as long as the string which . controls him is pulled. The clowns illustrated are suspended from a pulley The colored wax is heated over an alco- hol flame and then applied to the vase 889 Decorating Pottery with Sealing Wax OTTERY can be decorated with sealing wax. A ready-made vase is cleaned thoroughly. Then the colored wax you’ have selected is softened in an alcohol flame. Holding the vase upside down, apply a daub of the wax. Move the vase verti- cally up and down in front of the flame to spread the wax. Apply additional daubs to. the surface and spread them out in the same way until the entire surface of the vase is covered. The heat from the flame thins out the wax and glazes it. Thus a one-colored coat- ing is obtained. More pretentious effects are-made by “flowing” a wax of one color into an- other of a different hue. After the tonal color has been ap- plied over a portion of the vase, a daub of another color is, allowed to flow into the first color in such a way that no line of join- ing is formed. The secret * of success lies in manip- ulating the flame. Queer Rivers Which Are Natural Curiosities MONG the natural curiosities may be mentioned several rivers. There is a river of pure black ink in Algeria, formed by the union of two streams, the water of one being impregnated with iron and the other with gallic acid, drained from a great swamp. Kentucky has its Hidden River, the origin of which no one knows. It vanishes into a deep cave and is thereafter lost. In Siberia a tributary of the Lena River runs over soil deposited on a layer of ice nine feet thick. 890 A Trowel Which Places and Molds Concrete Curbs N adjustable trowel which greatly increases the speed at which concrete Popular Science Monthly man, E. Bourdells, and an American, Captain Eley, have all three independently conceived the scheme of an arrangement in curbs can be made, has been devised by Charles Upham, of Odell, Illi- nois. The mere ad- justing of its horizontal top-arm will vary the height of the curb as the trowel is pushed along over the roughly- shaped concrete previ- ously placed along the road. The trowel is made in three pieces. The two side arms are held facing each other at the proper distance by the top arm between them. This arm slides up and down the slots shown in the side arms. In these the height ad- justments are made. The top arm is flared so that it continuously pushes the concrete downward while being A more compact mass is thus formed than the ordinary flat trowel guided over it. could produce. Three Separate Plans for Making a Gun Think ILITARY rifle designers have little faith in the troops. wrong elevation—and itself when pointed-at the correct one. Nearly all errors in battle are er- rors in the eleva- tion of the rifle; the bullets strike too high or too low. The battle lines, being.long, usually take care of side errors. A German, A. Miiller,a French- scale The crude and rough-and- ready sights they install and the fool- proof mechanism go to prove this. Their latest idea is to make the rifle refuse to fire when pointed at the Distance and thread Pivot eas As the trowel is pushed along, the top arm is adjusted to the required height, thus shaping the concrete the stock which will prevent the rifle from being fired save at the correct angle. The Frenchman’s. idea is to place an electromagnet in the stock. The electro- magnet controls the ac- tion of the trigger and locks it normally against releasing the sear of the gun. A mercury column in the stock closes the electro- magnet circuit when the gun is held at the correct angle, unlocks the sear, and permits the soldier to fire the gun. If the angle is not correct, the mercury fails to touch both ends of the open circuit, and so the gun remains locked. The German and the American ideas are practically alike in principle in that they make use of a pendulum, or pivoted and swinging weight in the stock of the gun, to lock the sear against firing, save when the gun is at the Range setter Dial distance intelligence of _ indicator r even to fire Rackand sprocket Adjusting screw awe = Rang indicator correct angle to score hits. Mercury level ‘siege The French gun has an electromag- net in the stock which controls the trigger action The American gun, like that of the German, has a pivoted weight in the stock to lock the sear against firing except at the correct angle a a a Popular Science Monthly Stopping Mexican Bullets with Sand-Filled Oil-Cans EN residents of Naco, Arizona, a border town, began to barricade the walls of their homes against Mexican bullets, one man made a visit to the town dump and obtained every available five-gallon coal oilcan. These he filled with sand and then built a wall with them against the side of his house facing the Mexican line, about two hundred yards distant. About one hundred and fifty of the cans were re- quired but he had little - difficulty in finding- this number; for Naco, like hundreds of other West- ern towns, is a place where coal oil is not sold “‘loose,’’ but is obtaina- ble only in square tins holding five gallons each. When the task was completed the man had the equivalent of a solid wall of sand a foot thick along the side of his home. During a battle fought on the Mexican side of a, the town in Janu- ———. ary, 1915, when the Carranza The new type of crank-operated spring- forces holding hammer drill used as a breast drill Naco, Sonora, were attacked by Yaqui Indians, hundreds of bullets came across the line and this unique barricade stopped all that came its way. The homesteader . carefully repairs and refills any of the cans that become damaged. 891 Drilling Holesin Concrete witha Crank- Operated Spring-Hammer Drill _ RILLING holes in concrete has always been tedious and slow. It has been quickened by the introduction of a new type of crank-operated spring-hammer drill which delivers fifteen hundred blows a minute and uses hollow drills instead of star or fluted drills. Hence all the material removed is pulverized or ham- mered to a dust. The device may be used as a breast-drill for holes in vertical walls or for holes in ceilings or beams. The drill consists of a hollow barrel in which reciprocates a piston or hammer against the compression of a spiral spring at the handle end. The movement is produced by a ratchet- wheel turned by two hand cranks. As the ratchet is revolved the piston carrying the drill at its free end is forced back against the compression of the spring. As the ratchet tooth “escapes, the piston jumps back under the expanding coil spring. Thefaster the ratchet is turned the greater the num- ber of blows transmitted to the drill, which is rotated in its socket in the usual manner. The ten- sion of the spring may be adjusted to vary the force of the blows by means of a collar bearing against the handle end of the spring, this collar being moved in or out through the medium of a threaded bolt and outside thumbscrew. The device has a telescoping extension for drilling holes in ceilings and the under- sides of beams. It has found a ready market among the firms mak- ing and installing sprinkler . systems on account of the ©=| ease with which the holes are drilled for the supports to | hold the sprinklers in place. Plumbers and heating and | electrical contractors make | use of it for drilling in con- | crete, brick walls or stone thick along the side of the house facing the Mexican line for expansion bolts, pipe hangers and the like. Entertaining the Crow The modern scarecrow is a yelling gymnast that twirls with the wind — By George Worts T is rather common knowl- edge that scarecrows are there to scare the crows away. If the unhappy figure, flapping in the breeze on its hickory limbs in the center of the cornfield, happens also to discourage the advances of the sparrow and the coyote, your average farmer is perfectly satisfied. For the same reasons that childless indi- viduals know much more about raising sons and daughters than do fathers and mothers, persons who have never been nearer a farm than the observation platform of a fast train, know all about scaring the crows away. Recently, several humorists, disguised as inventors, brightened up the columns of the Patent Office Gazette with various im- provements upon the time honored, flapping, cornfield variety of scarecrow. While their inventions are labelled scarecrows or ‘‘crow jacks,” the descriptions which accompany them are delicious satire. The inventors seem to have decided to furnish everybody with a laugh, from the employes in the patent office to the crows in the cornfield. Each one of the little group of humorists was positive that the average farmer is not pleased with the dividends, so to speak, which his old suit of clothes draped over the usual hickory limbs or old broomsticks has been declaring. Before these merry-makers ap- peared with their side-splitting The cornfield gladiator who waves his swords with the wind 892 ideas, it had been our opinion the world was that of the man who goes through all the ‘mental gymnastics necessary to calculate, for example, that if all of the beans baked in Boston during one week were placed end to end, they would stretch from Hoboken, N. J., to Mars, with enough left over to pave a road twenty feet wide from Gallapolis, Ohio, to Moose Jaw, Saskatchewan. But we overlooked the occupation of inventing improvements for old man scarecrow. On the other hand, why waste old-clothes scarecrow of our fore- fathers? scheme that a New York man applies to hens? “The hen is instinctively a well mannered bird,’’ says this poultry- man. ‘Be polite to her, and she will roost awake nights, schemes to increase her output.” What stands in the way of applying this plan to scarecrows? . i) board ly, the real dis- || am HE ire tance in miles traveled by this expanding por- tion of the neb- ula must have been enormous. duces expenses a corresponding amount is now being intro- duced all along our coasts. For- merly a_ coast steamer had to wait for the tide to come in be- fore she could steam up to the loading dock. Then the cargo was hauled up by the ship’s der- ricks piece by piece, or it was run up the gang- way by the truck load. But with the eleva- tor designed by Harry Barlow, ofSeattle, Wash- ington, an entire platform of ma- terial can be quickly carried up to the ves- ‘sel’s deck at once. the tide is out, Attempt after attempt was made to explain this apparently incredible phenomenon; but nothing really satisfactory has yet been suggested. Far less dramatic, but of immense value, is the photographic work done at Harvard in mapping the sky. The map is not made once for all, but its separate sections are constantly rephotographed. The plates are stored in a fireproof building erected especially for the purpose. With such a photographic record, it becomes possible to study the past history of a star at any time. The study of these photographs constitutes a very important part of the work, which is done mostly by women. The platform of the elevator is brought to the level of the dock where it is quickly loaded. motor then hoists it to the deck of the steamer the light sound boat carrying ‘the elevator steams from the dock to the vessel anchored near by. A small electric motor mounted on the top of the elevator structure furnishes the power for the half dozen cables used. The motor controls are placed at any point that affords the operator an unobstructed view. After the operator has brought the plat- form to the level of the loading dock, the filled platform can be easily raised up to the deck of the largest steamer. Level trucking is thus afforded in place of truck- ing up or down steeply inclined gangways. This fact makes the elevator indispensable for loading explosives or fragile wares. An electric either And _ if Popular Science Monthly An Improvised Tree Sprayer and Fire Engine Combined T World’s End Farm, owned by Mrs. “W. W. Blackmar, and situated at Hingham, Massachusetts, are many inter- esting contrivances. Among them is a tank on wheels, used as a fire engine and sprayer combined. An old twenty-five horsepower automo- bile engine is mounted on a wagon-truck together with a pump and a four hundred and sixty gallon tank. The entire weight is nine thousand, five hundred pounds. The contrivance was improvised by Mr. C. R. Goodhue, the superintendent of the grounds. It is used for spraying trees, and, in cases of emergency, to put out fires. It throws a spray eighty feet in the air with sufficient force to completely clean the trees of insects and their eggs, leaving germicide solution on the leaves of even the topmost branches. Since this method of spraying the trees has been in use, the production of - fruit has considerably increased. During the past year thirty-five thousand gallons of sprayer were used. Disastrous fires have also been eliminated; for with the fire engine right on the premises, a fire is stopped at the very start. 909 _ Grasshoppers Which Fly a Thousand Miles Out at Sea HE grasshopper would seem to have nothing in common with the seagull, yet grasshoppers have been picked up in swarms at sea, 1,200 miles from the nearest land. The African grasshopper has been known to cross the Red and Mediterranean seas in destructive numbers and even to fly to the Canary Islands. For the most part these grasshoppers are of a migratory species (Schistocera tariarica) noted for its great flights. The bodies are about four inches long and are equipped with large air sacs in addition to the usual breathing tubes. These sacs buoy up the insect so that it is able to stay in the air for days ata time, exerting practically no effort at all. During flight its speed varies from three to twenty miles an hour. When it is tired it rests on the water and is borne along on the waves. aii oy Se as _ The tree-sprayer fire engine throws a stream eighty feet into the air. For the more strenuous fire-engine duties large open nozzles are used instead of the ordinary spraying nozzles 910 An inclined rear wall on the tender allows the coal to slide Popular Science Monthly 7 forms of motive power can be ~ : used with the apparatus. The side walls may be made to slope toward the center with advantage, for gravity is a cheap force and should be made use of wherever pos- sible. The pushers extend clear across the bottom of the tender and move the en- tire lower stratum of coal with each forward stroke of the reciprocating piston. The device is the invention of Charles L. Heisler, of Sche- nectady, N. Y. steadily down to a point in front of the vibrating pushers Supplying Coal to the Engine by Means of Vibrating Pushers HEN the coal bin of a locomotive is full there is but a step between the fireman and the supply, but as the great iron horse eats back its food supply there is another step and then another, until firing partakes of the nature of a Marathon race. How to get the coal to the firemen in a big modern locomotive is a problem to which inventors have been giving their attention. Strictly speaking, the device which is illustrated and which is intended to solve this problem is a vibrator rather than a conveyer, for the coal is not carried from point to point in a receptacle but is shoved by a vibrating pusher, which then recedes, allowing more coal to drop in front of it, and then pushing that on- ward, the movement being transmitted to the fuel in front. The pushers are actuated by a reciprocating pis- ton, suitably governed, and preferably situated in the engine proper, but with such readily detachable connections that the tender can be disconnected from the locomotive when desired. The mechanism is con- trolled by a lever, which regu- lates a throttle in the steam connection with the vibrating piston and cylinder and which is under the direct manage- ment of the fireman. Other A bulb inside the device throws its light around the egg Candling Eggs in the Newest Way Without the Aid of a Dark Room S far as the consumer is concerned there are only two kinds of eggs— good ones and bad ones; and usually he cannot distinguish one from the other until he breaks the shell. But to the dealer there are several grades between the best and the unusable eggs. For years these grades have been determined by candling—a _ pro- cess requiring a dark room and a point of light against which the egg is held to get a kind of X-Ray view of its in- terior. The pro- cess is slow and the conditions under which the men must work are more or less unsanitary. A newer method em- ploys the candling de- vice shown in the il- lustration. This device confines the dark area where it belongs—just around the egg. The projection on top of the device has a slight slant so that it is impossible for any light to get to the egg from above. With this device one room may be used for can- dling, grading and packing. \ | ;DIAPHRAGM PRESSED \| AGAINST REFLECTOR Popular Science Monthly Simply Turn the Faucet and the Sausages Are Filled N making sausages and bolognas the meat is first chopped and highly seasoned. Then it is forced under pressure into a cylindrical case or skin. After the sausage has been pre- pared, it is placed in a large vat and forced through a nozzle over which the skin has been drawn by the op- erator. Theillustrationsshow , how thisisdone. When the valve is opened the : meat rushes into the hol- low skin like water from a hydrant into a fire hose, distending the skin and filling it out to capacity. The sau- sages are then tied and are ready for the market. The preparation of the skins is an elaborate proc- ess involving many washings. - A Concrete Cooler Which Chills by the Action of Evaporating Water Th naga cylindrical compartment, five feet in height and three feet in di- ameter, with a narrow door a foot wide At: the top is a concrete reservoir from which the water overflows down the sides of the cooler Photos by Universal Film Co. The skin which is to be filled is held tight over the nozzle and the sausage meat is forced into it mounted on metal hinges, all made of re- inforced concrete, composes the body of the cooler. Pass- ing vertically through the cen- ter of the cylindrical body is a piece of metal piping upon which have been con- structed, at uniform intervals, five flat, imi- tation-porcelain disks which serveas shelves. Both the upper and lower ends of the piping rest in cup-shaped sockets so designed that the pipe and its disk-shelves may be readily turned. The shelves may thus be caused to pass before the door opening with the boxes and vessels upon them. To provide proper ventilation, two small holes are cut in the sides of the body near the top, and these are covered on the inside with fine screen wire to keep out insects. The body is mounted on a flat concrete plate raised about twelve inches off the ground by supports. On the outer edge of the surface of this plate, which extends beyond the sides of the body, a shallow groove has been made to contain a moat of water. This moat forms a barrier to the invasion of ground insects. The top of the body is surmounted witha concrete reservoir which has to be filled once a day with water. This water finds an escape at the bottom of the reservoir through four small valves which are set diagonally opposite each other. The water from the valves first spills into a small trough surrounding the top of the body and then overflows down the sides. The evap- oration of this water as it spreads over the cooler’s sides keeps the inside of the cylinder almost as cool as if ice were used. 912 Popular Science Monthly What the Zeppelins Have Cost London in Acci- dents and Deaths OME Secretary Cave, in a recent speech in the House of Commons, gave the total number of fatal accidents in the London streets between sunset and the war and the total num- ber of persons killed by Zep- number of fatal accidents in the Metropolitan Police Dis- trict during the hours of darkness between August 1, 1914, and January 31 last, with an Loading and unloading heavy barrels electrically-operated crane A Pigmy Electric Crane with the Strength of a Giant IME is the all-important factor in the delivery system of any large distribut- ing company. That is one reason why motor-trucks have superseded the horse and wagon. But it sometimes happens that more time is consumed in loading or. un- loading a vehicle than in transporting the material to its destination. there is a persistent demand at present for cranes and lifting machinery which will serve the truck without delay. The illustration shows a novel type of electric crane employed to load and unload three hun- dred-pound barrels on It does its work in one fifth the time required to roll the barrels and lift them on the truck by hand. Another advan- a_ truck. tage is that thebarrelsare not damaged -or handled roughly in unloading and there is little. or no danger from accidents. It requires the services of only two men. DISPENSING CYLINDE R Thus STORAGE CYLINDER CONTAINING BUTTER PISTGH was nine hundred and fifty- four. The number of persons killed by Zeppelins in the same district was one hundred and thirty- seven. In the city proper there were twenty-nine fatal accidents and thirteen persons killed by Zeppelins. Serving Individual Portions of Butter by Machinery N automatic butter-serving machine, such as is shown in the illustration, will cut and deposit the individual squares plates in a fraction of the the health experts. The butter is placed in a cylinder inside the machine, from which it is forced through an opening in the bottom by means of a plunger geared to a handle. A downward throw of the handle moves the plunger cutting wire is simultane- ously swung into position. The upward threw of the haste reverses the cutter shaft and forces the wire through the butter, thus dwiding it into individual portions. These it throws forward on to the plates set to receive them. A separate chamber in the center of the machine is filled with ice to keep the butter at the proper temperature. There are eight storage cylinders and a compart- ment for ize the length of a notch. WHICH PUSHES CARTRIDGES INTO BREECH ,& IS OPER: ING, FORWARD NT OVER PROJECTION’T® & THROUGH iar, STRIKES FIRING PIN GL EXPLODING CHARGE One of the many types of automatic rifles recently evolved to meet modern conditions. It weighs about twenty pounds and is operated much like an American self-loading sporting rifle HERE is no dividing line between a machine gun and an automatic rifle. Both types load, fire, eject the empty shell and load again by virtue of the recoil or the gases of the gun operating clever mechanism in the breech portion. They fire just as fast as the mechanism will operate as long as the trigger is held back, and the supply of ammunition is kept up, the speed varying from three hundred to six hundred shots per minute. The American Benet-Mercié and the British-American Lewis gun represent the common idea of the automatic rifle, both being light and rifle-like in outline. The weightier Maxim is the typical machine gun, water-cooled and rather ponderous. The gun illustrated is even more rifle-like than either the Benet-Mercié or the Lewis. This gun is merely another modification of the light machine gun idea, and is not unlike our own Benet-Mercié. But where the mechanism of the Benet-Mercié is operated by gas borrowed from a tiny hole bored in the barrel and admitted into a regular gas-engine sort of cylinder with piston operating the gun, the weapon shown is operated much like a well known make of American sporting self-loading rifle. A backward movement of the sliding barrel unlocks the breech-bolt and permits the recoil of the powder gases in the chamber to open the breech block, eject the empty shell, cock the striker, bring a fresh cartridge into position, and compress the spring that serves to close the mechanism. Then the gun instantly fires itself again. In both this gun and the Benet-Mercié the cartridges are fed in by means of a flat clip holding twenty-five or thirty cart- ridges. The Lewis uses a drum with several layers of cartridges, the Maxim and Colt use a webbing belt holding two hundred and fifty rounds. 917 Dispatching Cars on One-Track Lines A new signaling system by which one man controls any number of cars ling interurban cars on one-track trolley lines consists of an indicating instrument at the dispatcher’s office which constantly records the progressive positions of every car in service. This record is AN NEW signaling system for control- — The indicating instrument in the dispatcher’s office records on a revolving sheet of paper the progressive positions of each car in service At left: The signal lights in the motorman’s box of the car. A red light means to side- track and a green light means ‘‘Proceed” electric pen and records the arrival of the car on the paper of the instrument. The dispatcher immediately moves a lever which controls a return circuit to the third rail. It is this which operates the signal- circuitin the car. If the lever is moved one way, a relay in the made electrically by a number of third rails which are strung along the tracks and at. the sidings. Whén the cars pass over one of the third rails, a shoe makes contact with the rail, and two electric circuits are controlled. One cir- cuit is in the car itself and another leads from the rail to the dispatcher’s in- car circuit connects in a_ green light placed above the motorman’s head, and the motorman If the lever is moved the opposite way, a red light is shown, which light warns the motorman to turn from his course into the next siding. Arriving at the third railat this siding, the motorman waits for strument. The closing of the latter circuit operates an When the cars pass over the third rails two electrical circuits are closed by a shoe, one 4% to the car and one to the dispatch office the ‘‘all clear” signal before going ahead once more. ; OTR proceeds on his way. - ee ee ee ee ee ee ; . - . ; 7 ee Popular Science Monthly Shower Baths for Hogs—A New Life Saver Used by Railroads HIPPING 919 The Simplified Turbine for Small Electric Plants HER- hogs to the slaughter house in freight cars is a precarious business. Strange to say, hogs, as a rule, do not suffer while the cars are in motion, but a great many die from over- heating while the cars are not moving. EVER electric power is developed, some type of driving unit must be used to turn the generators. In the newest power plants, thesteam tur- bine is being s¢di--& steam tur- bine may be considered as nothing more than a wind- Furthermore, the first warm weath- er of the season is more severe on hogs than the hot weather later in the season. A train may become stalled upon arrival at a division point and within twenty-four hours enough hogs may die from over- heating to cause the shipper or the railroad a great financial loss. To afford the shipper the protection he needs and to protect itself against loss, the Saint Louis and San Francisco Railroad has installed a hog-watering device at its principal division points. Immediately upon arriving at these points the freight trains carrying hogs are stopped and the hogs are given an im- promptu shower bath, as the accom- panying illustration shows. As a general thing a stream of water is first turned into the bedding underneath the hogs. After the bedding is well saturated the nozzle of the hose is turned to the roof of the car and the water falls on the hogs. A drain box is provided under the car to carry off the waste water. At the principal division points the hogs are given a shower bath to prevent them from becoming over-heated to The steam simply flows in a helical path at high speed. During half of its journey it forces itself against the turbine rotor, pushing it around mill adapted special conditions. Instead of wind striking against its curved blades, steam rushes upon them. The steam is directed by a nozzle, producing a compact stream of a tremendously high velocity which glances against one blade cast into the side of one of a number of driving wheels, and shoots into another blade on another driving wheel rotating beside it. Such was the old-type turbine. The complexity of mounting a series of driving wheels on one shaft made it an exceedingly expensive engine, practicable only for a large size plant. A new method of guiding the steam so that the series of blades on the same driving wheel can be utilized, adapts it for the small power plant. The blades are sunk into the periphery of the driv- ing wheel, and after the steam pushes against one, it is guided by a_ fixed stator in a_ helical path into another. After expending its energy on six blades, the power is con- verted into motion. Locating a Sunken Ship A bell-buoy marker is an old idea with a new application especially appropriate for the times AO. Tape A buoy provided with a bell which is rung by wave action continuously announces to passing vessels that a ship is submerged at that spot, until the salvaging ship arrives NOVEL form of marker for sunken vessels has recently been brought out, and is shown in the illustration. The idea is not new, but the modification here shown is interesting. A loose buoy on the deck is attached to one end of a coil of rope, the other end of the coil being fastened to the ship. The position of a sunken ship that is thus equipped will be indicated by the buoy, which will rise to the surface if the rope is of sufficient length. It is entirely possible to have the first coil attached to another, much heavier, and that in turn fastened to a cable of sufficient strength to aid in raising the vessel or assist in towing to shallow water. In this way the task of salvaging the ship would be somewhat simplified. The buoy may be provided with a bell, rung by wave action by means of suitable clappers spaced about the circumference; so that the ship will toll out its own funeral dirge, into the ears ‘of passers-by. 920 a : : i an | eas | Pe i ee | eT ro ee Te ee Electrically Operated Camera- Shutter for Photographing Birds N the attempt to photograph small wild animal life, particularly birds, it. is necessary to have some means of operating The magnets are attached to the camera bed with clamps where they operate the shutter release the camera from a distance. Many meth- _ ods have been tried with varying success, but the method described herein is conceded to be the best. The idea is simply to focus the cam- era on a spot where from pre- vious observa- tion the birds are known to come, and to have some means of operat- ing the shutter from a distance. In the springtime the best places to focus are on or near the nests, and in other sea- S = i A chickadee near its nest with a bill full of grubs and a tufted titmouse on a post, attracted by suet ESSE)" _===aRaB2B2_EEEE= FOR PRACTICAL sons on some suitable food supplied for the purpose. There are three methods now in general use for operating the shutter. In one a string is attached to the shutter lever and simply pulled at the opportune moment. F = . . - i. SERRE weer sad The spool for carrying the flexible cord incloses the battery for oper- ating the magnetic shutter release While fairly good, this is difficult to work at long distances and has the disadvantage of being liable to be operated by outside forces; such as. wind- blown twigs. A long tube at- tached to the pneumatic re- lease lacks the above disad- vantage but not instantane- ous in its action. Besides, the rubber will, in a short time, be- come hard and useless from lying on the damp ground and may be easily damaged in is i 921 922 handling. The electric type of operator, although a little more bulky, gives real satisfaction and is very simple. The illustrations plainly show the opera- tion of the device. The agitator proper consists of two magnets similar to those used in a call-bell. These when energized attract the armature above them attached to a long rod, which is attached to the shutter lever by a small wire hook movable on it so as to follow the camera front when focusing. The small weight on the rod is to steady the movement and to allow the magnets to operate on less current, being thus assisted by gravity. The windings from the coils are led to two small brass screws in the side of the base, and it is to these that the spring clips on the cable ends are fastened. The small clamp holds the apparatus to the camera bed without altering its action in any way and may be removed instantly when the camera is wanted for other work. No dimensions are given, as the instrument must be built to fit the camera for which it is intended. PUSH-BUTTON —ya BATTERY Dimensions for the wire carrier and battery, and the wiring diagram for the connections The flexible lamp-cord used as cable is wound on a wooden reel which also holds the batteries. The core of the reel con- sists of two wooden end pieces connecting the flanges. The two double-cell flash- light batteries are slipped between the up- per and lower pieces of the frame where they make contact with the spring brass clip fastened on the inside of the end piece. The wiring diagram shows the connection with the push button and camera. The entire outfit, including plate-holders and other paraphernalia needed, may be fitted into a small rattan suit-case. The tripod legs when folded may be strapped to the outside of it. The only other requisite is an unlimited supply of patience, but as something of interest is always in progress in the woods and fields the time thus spent is by no means void.—C. BREDER, JR. Popular Science Monthly Troubles with the Safety Spark- Gap on Motorcycles ee owner of a single cylinder motor- cycle equipped with a well known make of high tension magneto, experienced some trouble with it which he attributed Most high tension magnetos are provided with a safety spark-gap to prevent damage to weak magnets. He accordingly took off the magnets and had them recharged. Upon replacing them he found the performance of the magneto to be worse than before. He then dismantled the magneto to look for further trouble in the armature and found what he thought at the time was the cause of all the trouble. As is well known most high tension magnetos are pro- vided with a safety spark-gap, the purpose of which is to provide a path to ground for the high tension current generated in the armature, and thereby prevent damage to the insulation, in case the spark plug wire becomes disconnected or the gap in the spark plug is too great. Thesesafety spark- gaps are arranged in various forms and in this particular type is arranged as shown in the accompanying illustrations. — The safety spark-gap back of the col- lector ring is clearly shown in the illustra- — tion. In the diagram the armature winding — SPARK P HIGH TENSION.” CABLE ig ae TO L \ INTERRUPTER \ SAFETY SPARK GAP A diagram of the armature winding to show how the safety spark-gap should be connected in which the safety spark-gap is located is also indicated. 4 Anyone not experienced in the construc- — tion of magnetos would be likely to jump _ to the conclusion that the two ends of wire _ separated by a short gap. were originally - one continuous piece and the break was _ the cause of its not working properly. _ This was the conclusion reached by the investigator in this case and he proceeded _ to close the break with wire and solder. Upon starting up again it still refused to work. Having reached the limit of his _ knowledge of magneto operation he took _ the motorcycle to a repair shop where the | ; : : A q a Md » “in & ; ; : : : : " | : : 2 : _ trouble was soon found to be due to the magnets being wrongly replaced, that is, two ends of unlike polarity were placed side by side instead of like polarities: This would indicate the advisability of carefully marking magnetos before removing them _ so that they may be properly replaced. In discussing the above incident with others the writer found that this safety spark-gap is frequently mistaken by -amateurs for an accidental break and treated accordingly.—PavuL Justus. Filling Wide Vertical Cracks and Seams with Putty puttying up a wide crack between two 4 boards, excelsior may be used to bind the heavy mass of putty together and prevent its falling out. The putty is worked into the excelsior until the two combine in a plastic mass. After forcing the composi- tion in tight, apply a smooth coat of putty over the surface. This method will be found convenient where holes or cracks would otherwise have to be filled with an inlay of wood.—James M. Kane. An Inexpensive Stove for Fruit . Canning Purposes | Bee woman has solved the problem of an outdoor stove for canning and 3 preserving in summer, by utilizing an old - galvanized tub. A hole was cut in the _ bottom, a door in the side anda stove-pipe hole in the opposite side. A joint and an _ elbow of pipe made the stove complete. It burns wood, and is piaced in a shady spot on the hill back of the house. There the summer canning for private and com- mercial use is done in a larger measure of comfort than could be had in the kitchen. The canning outfit is as simple as the outdoor stove. It is a common wash boiler and lid with a piece of mesh wire cut to fit the inside, and to lie flat on the bottom of the boiler.—Paut Greer. Popular Science Monthly 923 A Handy Farmer’s Anvil Made Out of a Railroad Rail F there is a piece of discarded railroad rail at hand a very convenient anvil can be constructed as shown in the illustration. The length of the rail used in making this anvil is 36 in., and is placed in an inverted position on a stand-made of 2 by 4-in. oak timbers 30 in. long. The upper ends of these pieces are pointed and fitted in the sides of the rail and clamped together with bolts. The bottom part is well braced. A board is laid on cross rails for a shelf. The end of the rail is pointed and cut to a " = > An inverted railroad rail rigidly supported ona substantial stand makes a convenient anvil shape similar to the end on the ordinary anvil. A hole is also made through each side projection for punching and to hold a hardy.—Roy PuGu. Lawn Sprinkler Made Out of a Length of Pipe HE method of watering lawns here described will appeal to those who have held a nozzle in their hands for an hour or more at a time. Get a 20-ft. section of 34-in. water pipe and drill 1/16- in. holes in it about every 2 ft. A coupling which will join the hose to the pipe can be procured for about twenty cents at most hardware stores. The piece of pipe can be easily moved from place to place over the lawn.—W. A. PaRKs.” Making Movie Films for Artistic Projection T is a generally accepted theory that art is far removed from anything me- chanical. Weare told by artists that where mechanics and matter-of-factness exist, A special shutter opens and closes gradually to make a fade-in and a fade-out picture there can be no true art. But how about the modern film plays? Even the casual attendant of motion picture theaters can not have failed to notice the highly artistic merits of modern film plays, especially dur- ing the past year. One by one, striking photographic tricks have been introduced, until today even the most commonplace scenic film is replete with pleasing effects. Strange to say, these artistic arrangements are produced by simple mechanical devices which in the majority of instances do not form an integral part of the motion picture camera. They are accessories. They are the products of the mechanic’s brains and the palette of the film artist—a heresy indeed, for here we have recourse to me- chanics in securing art. Perhaps the oldest photographic effect Popular Science Monthly in the films is the “‘fade-out,’’ as well as its companion, the ‘‘fade-in.” the entire picture, while retaining its origi- nal size and shape, gradually darkens until it disappears in a mass of black. In the reverse operation, the “‘fade-in” gradually develops a picture out of blackness. The fade-out effect is secured simply by slowly reducing the opening of the camera lens by means of its iris diaphragm, so that successive exposures receive less light. Hence the positive print becomes darker and darker. .The second effect is merely a reversal of this operation. However, it often happens that the iris diaphragm of a lens does not close com- pletely, in which case unusually light sub- jects refuse to fade out thoroughly. For this reason other means are sometimes em- ployed. One of these is a special form of shutter, the opening of which closes grad- ually as the scene is being photographed, the action being entirely automatic and adjustable for a complete ‘fade-out’ or “‘fade-in” in a given number of feet of film. Double exposure work produced by the fade- out and fade-in with the curtain method In the first, — a a a en es ais ey oe Se ee a in front of the lens, running from trans- parency to opaque. _ For dissolving views, as in cases where -one scene appears to blend into another in a gradual and pleasing manner, the “‘fade- out” and the ‘“‘fade-in” effects are em- ployed. The first scene is Popular Science Monthly _A screen of graduated transparency ‘slides 925 camera lens, and equipped with an iris diaphragm which is manipulated by a long lever. Since the sharpness or softness of the vignette edge depends entirely on the distance between the diaphragm and the lens, the tube is of telescopic construction to permit of sharp or soft outlines. When the diaphragm is placed as faded out by the camera man, who carefully counts his turns or notes the posi- tion of his film-indicator hand. He then winds back the film the same number of turns, or until the hand on the indicator has re- turned to the position where the “fade-out” began, keep- ing the lens covered all the while. Then, with the far away from the lens as the tube will permit, the circle vignette is sharp, but if the diaphragm is brought near to the lens, the outline is barely discernible, al- though of course the device accomplishes its mission just as effectively, and far more artistically. Whether the vignette edge should be soft or hard depends en- diaphragm entirely closed, tirely on the subject which A circle vignetter in an ex- tension tube on lens barrel showing which operates lever A curtain dissolver for he begins taking pictures in the usual way for a ‘‘fade-in” effect, which i is timed the same as the previous operation for the fade-out. A new-comer in the film field is the effect known by several different names, such as a? 66 ? “circle vignette, circle-in,’”’ and “round dissolve,” which has met with great favor among film producers. In the films it causes a scene to shrink gradually, changing from a square or oblong image to a round image, which becomes smaller and smaller until it disappears in the center of a black mass. The effect is also used in isolating a character or an object, so that it will stand alone in a round, vignetted picture. At other times, it is used to soften the corners of an oblong picture. : The “circle vignette,’’ or whatever one may choose to call it, is produced by an extension tube placed in front of the usual A square closing dis- solver that moves all four sides gradually use in matching what is called a “‘split stage’”’ is to be photographed and the effect that is sought. Another recently introduced effect is the “square closing dissolve,’’ which at- tains the same ends as the circle vig- nette, but with the difference that- the effect is a square one instead of circular. In a “square closing dissolve’ the four sides of a picture move toward the center and the rectangular shape is preserved until the scene disappears entirely in a field of black. . The device employed to secure this result consists of ° two shutter leaves with their facing edges cut out to form a right angle notch, which through the agency of parallel levers oper- ated by a handle, overlap each other, more or less, as desired. Thus the size of the square opening formed by the overlapping 926 leaves can be altered, while maintaining a perfect rectangle. The square closing dis- solver and the vignetting shutter are gener- ally mounted in the same barrel so that either one may be used at will. In the case of the former device, it is placed as far away from the camera lens as is possible, so as to obtain sharp edges on the film images. Still another device, the ‘‘curtain dis- solver,” is similar to the two devices just mentioned. Its effect is to cause the top and bottom of the film image, or the sides, to move toward each other. If desired, only one side of the picture is moved so as to stimulate the pulling down of a curtain or the drawing of a screen, or rolling door across the film image. It is employed to secure a narrow picture or to isolate a single narrow object, such as a doorway or perhaps a railroad switch. The device em-. ployed consists of two shutter blades which may be moved toward each other or moved singly, by means of levers. Sometimes the ‘‘curtain dissolve’ is em- ployed in double exposure work, in which case its blades are used to mask certain sec- tions of the film during the different ex- posures. definite point so as to reserve a certain amount of space on each film square, while the first action is photographed. Here, too, the cameraman must keep track of the number of feet ef film that are exposed, and, masking the lens, wind the film back to the starting point. The other blade of the dissolver is then moved over to meet the first blade which is then moved out of the way of the lens. Great care must be taken that the action of the second exposure coincides precisely with that of the first, for otherwise the effect faiis to be convinc- ing and may even be ludicrous. This effect makes it possible for an actor to play op- posite himself. Entire film stories have been built around the cameraman’s skill in this form of double exposure work. In good work the two sections of the picture are so carefully matched that they blend together with no dividing line showing. Another method of double exposure work makes use of what is known as the “‘double . exposure box.’ This device comprises a simple box placed in front of the camera and carrying a piece of ordinary glass, through which the camera photographs the scene. In taking the first action, any por- tion of the film may be masked out by pasting opaque pieces of paper of any size Popular Science Monthly One blade is first moved up toa - and shape on the glass window of the box. The film is then wound back to the starting point, with the lens masked in the mean- time. after the glass window has been altered so that the portion formerly covered is un- covered, and the former transparent por- tion is covered. The result is that two dis- similar actions can take place in the same film scene. This form of double exposure, it will be noted, confines the different actions to separate sections of the film. It is some- times termed “‘split stage’’ double exposure. There is still another form of double ex- posure work where the two exposures are photographed on the entire film or are superimposed in part, such as the cloud effect, shown in one of the accompanying film strips. This effect is either obtained in the photographing, or in the double printing of the positive stock, with many interesting and weird results. Sometimes the titles of a film are printed in on the scenes, or the dialogue is printed in some convenient portion of a scene, which is — accomplished in the printing process. Dropper Bottle for Photographic Bromide Solution TEN per cent solution of potassium bromide is kept on hand in almost’ every photographic darkroom. The usual 4 developing formula calls for a certain num- — ber of drops of the bromide so- Drops of bromide solution forced out by pressure theotheracurv- ed tubeisinserted, its upper portion tapering This tube © like that of an eye-dropper. extends to the bottom of the bottle. At the top of the short tube a rubber bulb is — attached. When the cork is tightly fitted — and the bulb squeezed slightly, the bromide solution in the bottle will flow from the — tapered tube in drops.. The second action is then taken, — lution. A handy ~ dropper for this — can be made by — fitting a small © large-mouthed — bottle with a | two-holed rub- — ber cork and © insertinga short — piece of straight — glass tubing in to one of the © holes, while in — A Small Refrigerator Suitable for the Milk Bottle ANY a baby has died of colic or summer complaint simply because _ the milk it received was not kept at a tem- perature low enough to _ prevent the development of bacteria in it. In an ordinary ice-box the thermometer usually reg- _isters from 55 to 60 de- grees, Fahrenheit; but to be safe milk should be kept below 40 degrees. In its effort to better conditions for babies the Department of Health of New York city has planned a milk refriger- ator which any mother may make for herself. If you want to try one of these model refrigera- tors, this is how to do it: _ Get a wooden box from your grocer—any box _ will do provided it is 15 ia. deep. Buy a covered earthenware —_—o a a Popular Science Monthly 927 Detecting Leaks in Inner Tubes by Means of Smoke HILE in India recently I entered a motorcycle contest, which was of the town-to-town type. It was from Calcutta to Gya, a distance of 300 miles, over roads which were covered with small, sharp-pointed stones, old shoes, nails and other things such as are to be found where there is bul- lock traffic of the eastern type, all of which are liable to make small punctures. Not being able to procure water to test my tubes and locate minute leaks, I took a pocketful of cigarettes along with me and found the following method a wonderful time and tem- per-saver as well as the only means of finding such punctures. The defective tube is taken out and the valve removed. Then two or three crock large enough to hold a quart bottle of milk. Next get a strip of lino- _leum or oilcloth 1 ft. wide and 3 _ ft. long. Sew the : ends of the strip { i _ together and you _ will have a cylin- der which will fit loosely around the crock. ‘ Put a layer of sawdust or excelsior _ in the bottom of the box; place the cylinder _ in the center of the box with the crock in _ it and then pack the excelsior or sawdust _allaround them. Nail a few old newspapers _ on the inside of the top of the box and your _ refrigerator is ready for use. As soon as you receive the milk in the morning (do not wait until it gets warm) crack five cents’ worth of ice and place it ‘around the milk bottle which you have put into the crock. Cover the crock and close the lid down on the box. This will _ keep the milk near the freezing point no matter how hot the day. Take the crock from the box every morning to pour off the water—A. M. JUNGMAN. A wood grocery box and an earthen crock, some lino- leum, paper and exceisior make a milk refrigerator mouthfuls - of smoke are puffed into the _ tube, after which it is inflated as much as possible. The smoke will be seen to ooze out of any punc- tured place. The spot can then be sandpapered and dressed while the smoke is oozing out and locating the place for the repair patch. After the patch is applied the valve is again taken out to let the remainder of the smoke escape and the tube is ready for use again.—GEORGE THORNTON Norris. 3 3 ‘i ‘s 3 rey { } M i RL a Cementing Tire Reliners to Make Them Hold EFORE cementing reliners, the paint on the inside of a tire should be scrap- ed off. If possible turn the tire inside out, a part ata time, and buff with a power- driven brush. Neither gasoline nor other liquid preparations should be used. They gum up the surface and consequently make good work impossible. 928 Combining Different Woods to Make Fancy Indian Clubs O make the Indian clubs shown in the accompanying illustration, nine separate pieces and five different varieties of wood were glued together and turned to shape on the lathe. The resulting com- bination was very attractive and the work looked like a job of the very best inlay. No more than ordinary care was required to get a smooth appearing piece of work. Plenty of clamps were at hand, and the best glue obtainable was used in building up the pieces, the glue being given plenty of time for drying thoroughly before the next work was done. The center stick was first squared up, mak- ing the surfaces exactly 114 in. each way, and 18 in. long. To this stock two pieces of walnut 7/16 in. thick were glued, leaving the edges rough and projecting, as shown by the dotted line Fig. 1. After the stick had dried in a warm place for 12 hours, the clamps were removed and the edges planed down, even with the stock. Two more 7/16-in. walnut pieces were glued to the other two sides, as shown in Fig. 2, and the rough edges planed as before. The result was a stick 2 in. square. In the same manner another layer of different woods, \ in. thick was built up. The last layer was used to make the heavy end of the club. Its length is only 12 in. measur- ing from the thick end. alae HEI RE ih \ \\ is Ni! IS Mt IK oe ed FIG.4 TO FIND CENTER FIG3 END VIEW Manner of arranging the different woods for making the outside contrasts to the surface The piece was then ready to be put into the lathe. Great care was taken to find the exact center of the 11%-in. center piece, as illustrated in Fig. 4. Failure to get the Popular Science Monthly piece properly centered in the lathe will — result in unequal faces of wood in the clubs. — By using a gouge, the block was quickly — rounded. A mark was made about )4 in. from the heavy end, and exactly 17 in. measured off to the end of the handle. At 114 in. from the handle end the piece was cut in to % in., the final size. The 114-in. part was turned down to a ball 114 in. in diame- ter, to form the handle. The base of the'club is 154 in. thick, and at a point 5 in. from the ~ base the diameter is 234 in. The stick was turned smoothly be- tween these points, giv- ing the shape as shown ~ in the photograph. Most — of the cutting was done — with the gouge, and the © piece was finished with — the skew chisel. In order that the ‘ pair of clubs’ should match up well, it was necessary to use care © in cutting the second one to the exact size of the first. To do this, the finished club — was measured every inch, and the diameter — of the second was made exactly the same — as that of the first club at all corresponding ~ points. After cutting to size, all chisel marks — were removed with a medium-grained sand- paper, and the piece was finished with — No. 00 (very fine) sandpaper. While still in the lathe each club was given a coating ~ of linseed oil, which was rubbed in with a rag. Following this, a coating of shellac was put on and dried, then rubbed smooth ~ with No. 00 sandpaper. The club was then removed from the lathe and the rough ~ ends were cut and smoothed. A coat of — floor wax well rubbed on produced a high © polish and proved to be an excellent finish. 3 Good contrasting effects were obtained by the use of the different woods. The clubs in the photograph have a center of sugar maple, a layer of black walnut, and top pieces of red cedar, burr oak, and red oak. Various results may be had by com- binations of other contrasting woods. It is best for the beginner to practice on cheaper | woods until he is thoroughly familiar with the lathe —DEAN G. CARTER. . The appearance of the clubs when finished Popular Science Monthly A Convenient Method of Handling ; Dangerous Acids CIDS are, at best, a nuisance to handle. {\ The arrangement shown in the illus- tration, however, solves the problem. The original carboy of acid is shown at A, and Bisa bottle with a stop-cock at the base and a tightly fitted two-hole rubber stopper in the mouth. The two are connected by a glass tube C. The tube passes from the bottle B down through a loose cover D placed on the car- boy to keep out dust and dirt. It should reach to the bottom of the carboy and be slightly bent at the lower end to allow the acid to flow out freely. The short glass tube in the bottle B, is connected by rubber tubing to an aspirator or suction pump. . Starting the suction pump reduces the pressure in the bottle B, and the acid is forced up into it by the external pressure of the air upon the surface of the acid in the carboy. Thus, the acid is caught and held in a closed vessel, from which it may be conveniently drawn off as desired, without waste or danger. No in- jurious fumes escape into the room and there is no possibility of burns being received from splashing, as the containers are not moved until they areempty. The acid is kept clean also. . from carboys with suction Fine Aluminum Filings Make a Violent Explosive 5 gad aluminum filings, made into a fine powder, form parts of two of the most destructive agents is little known. It has been used in the Austrian shells as a component of the high explosive agent. This explosive is known as ammonal, a mixture of five or eight parts ammonium nitrate and one part of finely powdered aluminum. Its explosive violence is tre- mendous. It is one of the few explosives that have never been used as propellants. No gun known to warfare could resist its suddenness. For this reason it is used only in projectiles. 929 Uncleanliness the Trouble-Maker — for the Vulcanizer EPAIRMEN are often puzzled when a tire taken from one mold looks better than one cured at the same time in another mold. Both operations may have been performed in the same way, yet the results were different. A dusty finger print, drop of moisture, a little oil from a tool, an insufficiently ce- mented spot at the edge of a patch, a tiny smooth space missed by the buffer—any one of these may have caused the difference. Cleanliness and carefulness are always the first requisites for successful results, and the repairman who always inspects his work carefully after each operation, is the most likely to find the little trouble-makers before it is too late. A Screen Door with a Special Exit for Flies HE fact that a fly will walk over the entire sutface of a screen sometimes . trying to get out, led to the experiment which resulted in the exit attachment shown in the sketch. An ordinary screen was used in its construction and an outlet formed 6 in. from the top. The screen was placed in the window with the exit-opening pointing outward so that the fly in his travels would walk out. The screen is cut and a V-shaped extension applied. The small end has an opening large enough for the fly to pass out easily. CROSS SECTION —— The projecting part shown at the top allows the flies to pass out but they cannot return This device is valuable because it allows the flies within a room to escape and pre- vents their return.—C. H. Tuomas. 930 An Old Barn Converted into a Tractor Shed HE accompanying illustration shows a very novel and efficient tractor shed which was made from a part of an old barn by removing Popular Science Monthly How to Patch an Aluminum Crank-Case HILE riding over a rough road I ran > over a sharp stone which struck the bottom of the crank-case with such force | that it punched | the upper part of the barn and constructing a roof over the lower part in which the horses and cat- tle were former- ly kept. Since the traction en- gine did not eat hay or food, the top part of the barn was not needed. The present roof of the shed is just about on a level with the general surface of the ground and does not intrude itself upon the view. The traction engine is kept in the lower half of the shed which has been dug a little deeper in order to give more head room, and the other half is used for the storage of implements and tools. It also contains a tank in which can be stored 1,000 gal. of gasoline. A large pipe runs from this gasoline tank ’ up through the roof and the tank may be filled from the outside. | This type of shed is very neat.—HAMILTON A. HOOPER. The Right Knot for Making a Slip- Noose About a Bundle HEN tying a large bundle first loop the cord about it and fasten the tie; then carry the cord around as needed. The right knot for _ this first loop— ' one that draws | tight and does not slip—is tied as shown in the mM illustration. _ The knot is then aaa) US Knot for a slip-noose drawn together around a_ bundle and the loop tightened around the bundle. Then pro- ceed with the cording.—TuporR JENKs. In this instance the lower part of the old barn made an excellent tractor shed also a cool place for storing gasoline Ie, a hole in the — metal, thereby engine. I took the nearest re- was told that an aluminum crank-case could not be mended, and that it would be necessary for me to purchase a new one. I did not like the idea of order- ing a new crank-case and waiting for two or three weeks to get it, so I decided to try the noble art of patching. I took the punc- tured part off, cleaned off all the oil and dirt, then with a mallet I drove the inside until it was almost out to place. I then poured hot lead in the cracks and crevices on the inside and did more pounding, al- ways keeping plenty of lead in the crevices until I had the dent out perfectly smooth. There was no hole as the lead had filled all cracks and was pounded in. Then by carefully dressing the place I had a patch which wasscarcely noticeable. Themachine was used for years and the break never gave any trouble, and could be detected only by careful. examination —C. A. SPAESER. dias | Making a Paint that will Stand Washing O make a washable water paint, mix 25 lb. of the best whiting with 24% gal. of water and let it stand overnight. The best way is to pour the water on the whiting and not mix it. The water per- colating through the mass during the night makes a smooth paste. Work the mixture into one gal. of raw linseed oil. This is best done with the hands. The paste may then be thinned to paint consistency with oil, turpentine and driers. The paint will have sufficient gloss to be attractive and will wear well on inside work. letting out all. the oil from the © the machine to | pair shop and ee Ft rte “Ye - IMPLICITY, convenience and com- pactness are the general features of this economical house. It has a large front porch facing east, door cas- ing of light oak, body of house cream color trimmed with white, and- shingles light green. The entrance is in-a small reception hall or vestibule with a long mirror behind the front door covering the stairway. There is a small hall or passage way from the vestibule to the kitchen, allowing a person to enter the kitchen without going through the living-room. This hall is seldom found in small houses. The basement door when opened closes the opening in the hall to the vestibule. There is also an outside basement door. _ Between the vestibule and the large living-room are two pedestal bookcases 4 ft. high. The living-room may also be used as a dining-room, upon special oc- casions, and instead of removing the dishes after luncheon the table with its load is pushed into the kitchen through a special opening. This opening is covered with a wall panel in two sections, the lower sliding up like a window sash inside the upper half, leaving ample room for a large table to pass through. There is a small buffet near the fireplace with drawers below for the table linen. The fireplace is set on the inside and the heat from the hot bricks in the back helps to keep the bathroom warm. However, a small hot water furnace heats the house. 2 — ee J AAT, --7 PA By Thomas Lappin , pe en There is sufficient inside wall space for a piano and a corner for the bed davenport. A wood lift is built in the wall near the range. It is filled in the basement with a day’s supply of fuel and drawn up where it is handy for the range. Above the lift are cupboards. The kitchen has plenty of cup- boards, bins and drawers. The iceless re- frigerator in the corner has cold water coils for shelves, and fresh air draft passes up through them. The drain board to the left covers a wash tray. This room is light and airy, and to save steps the table is set near the rear window, except when it is used in the living-room for guests. The bathroom is always warm, as it is heated from the hot water tank, which is placed in it, and the back of the fireplace. It contains cupboards, cabinets and a corner washbowl. The doors to the bath- room when opened effectually screen the bathtub and form a passageway to the bedroom. The toilet is in a separate room where it can be ventilated from the outside without cooling the bathroom. The plumbing is not put in for the con- venience of the plumber, but for the house- wife only, and if properly protected it will not freeze. Another new feature is the dressing-room set off from the bedroom. A long mirror may be set in the corner be- tween the two small windows. The bed- room can be reached from the living-room or the kitchen. The entrance to the stairway to the sec- ond floor is cleverly concealed by the mirror 931 932 door. There are two bedrooms for the children, or for guests, as the case may be, with a hall between them. In this hall back of the chimney is an extra toilet for the upper floor. It is lighted by a sky- light. From the rear room there is an entrance to a small sleeping-porch. There are plenty of closets and storage rooms. The furnace, though small, provides ample heat. It has a thermostat and a thermome- ter to regulate and register the heat. Different contractors have figured the Popular Science Monthly were hinged together, and a burlap blanket was stretched across the entire ring and stitched to it. Over the entire lower surface of this burlap, strips of felt or canton flannel were stitched 2 in. apart, each strip being cut into 2-in. sections 3 in. long and hung from the burlap. These hovers are 5 ft. in diameter—large enough to cover 225 or 250 chicks—the usual’ results from a 300-egg incubator. They are set in the laying pens which will house the pullets when raised. Two small SCREENED SLEEPING PORCH 4x14’ none STORE ROOM CHAMBER I2XI2 CLOSET SPACE UNDER ROOF, ~ TOILET i ' i I ' t 1 ' 1 t ' \ i ! 1 ' ' ' ! ! t CHAMBER 9xI\e' CLOSET LIVING ROOM 12'x20° BAVENPORT Floor plans of a very unique five-room bungalow built for comfort and convenience cost of this house where the specifications called for a double constructed, windproof, full cement basement, all built-in con- veniences, electric lights, gas, water, furnace, and first-class workmanship, to be from $1,200 to $1,400. A Chicken Brooder That Does Not Require Heat POULTRY farmer of Utah, who every spring raises several thousand chickens to keep up a large flock of hens, has dis- carded a rather expensive brooder house with fine heating equipment and now uses a very simple cold brooder. The saving of labor in controlling the chicks, the elimina- tion of the care of lamps, thermostats and regulators, and the fine efficiency of these hovers attracted much attention from poultry farmers in the vicinity. Two halves of a ring of 54-in. iron were made by the local blacksmith. The halves stakes are driven into the ground, to receive the bolts which hold the halves of the ring together. The bolts also serve to hold the ring securely in position. stakes catch the outer edges of the ring and support it at the right distance from the ground—about 4 in. Each brooder is first inclosed with wire netting having 1-in. mesh, 20 ft. long and 1 ft. wide. This is done for simplicity of operation and ease in controlling the chicks and herding them for the. first few days. When the chicks come from the incubators the wire fence is drawn around the hover, one-half of which is raised to permit the chicks to enter. Straw is placed around the outside edge of the hover in layers thick enough to hold in the warmth with- out cutting off the ventilation. . FP a ee ee ee ey Two other | ee ee Oe re et eae ee ee Cee -open all round and the chicks — wr tree — eae SS ee el ee . Popular Science Monthly On the second day the straw is pulled back and the circle of wire fence is enlarged $0 as to leave a 1-ft. open space all around the hover, into which the chicks may run without getting far from the blanket. Several times this first day a minute’s work contracts the wire fence, by sliding one end past the other, and so huddles the chicks under the hover = 933 Distributing Cards in a Pack and. Disclosing Them Si the four kings from the pack, also two other court cards—preferably jacks—and spread them fanwise, being careful not to show the jacks. In adjusting these cards place the two jacks back of the first king. As again. This is for education as well as to guard ee a a eee oe these jacks are hidden behind the king they are against chilling off too much, for many of the chicks will, on that first day, thus learn that the hover, with its ~comforting blanket and strips on their backs is the place to find warmth, comfort and security. This hover is can dodge back under it at any instant. At night, or if the weather strikes in cold through the day, a minute’s work closes in the fence and a few kicks put the straw protection around the outside. After the first two days the chicks take full care of themselves. Only at night are the closing up and the adjustment of the straw necessary. The only objection to a cold brooder is that the sudden change from the 103 or 105 deg. of the incubator to the cold floor, cold litter and cold blanket—if there is one—is likely to cause mischief and a serious check to develop- ment, although a large number of chicks raise the temperature very quickly. In this brooder this trouble is eliminated by the use of heated bricks. The night before the incubator is to be emptied a dozen bricks are heated in an oven, and are placed beneath the hover. Then heavy blankets or grain sacks are laid over them. In the morning the floors, the bedding and burlap are warmed so thoroughly that the chicks get no shock. After that no more artificial heat is needed. About a week after the chicks are put in, the wire fence is taken away and they have the run of the house.—Gero. F. STRATTON. SSS SEES <> SO RS SEIS RES RE Rings of iron covered with a burlap blanket to which strips of felt or flannel are stitched to hang down and cover about three hundred chicks invisible to the audience, who must be satisfied that the cards are all kings and nothing else. These cards are then placedon top of the pack. Statethatyouare about to distrib- ute the four kings in various parts of the pack. Take upthetop card, which is really a king, and exhibit it, if need be. The next card, being a jack, should not be shown to the audience, but should be taken up carefully and placed anywhere in the pack. The next card is also a jack, and it is placed in another part of the pack. The next card can be taken up carelessly and replaced on top. Three kings will be at the top and one at the bottom of the pack. When the cards are cut the four kings will be in the center. | 2 25 SAE wares. ¢ tit a Making a Bit Point Take Hold : in a Knot HE wireman frequently finds places, especially when boring overhead, where his bit stops feeding, and it be- comes almost impossible to make it take hold again. In such cases, take your bit out of the brace, and substitute one a size or two smaller. This will usually start to feed without any great trouble. After boring three or four turns, put the right size bit back in the brace. When it commences to bore, a little care may be necessary to prevent it from feeding too fast. If it should later on lose its hold again, the same method may be repeated. 934 Finding Leaks Quickly in Air Tanks HILE visiting a rock quarry I saw the workmen using a new method for finding leaks quickly in compressed air tanks. A plug was removed in the upper part of the tank and a large spoonful of oil of peppermint poured in. The plug was screwed back in and the compressor started. The leak was soon found by the odor of the peppermint. This method may be used to advantage for finding leaks in small acety- lene lighting plants—-EDWARD GYGER. Making a Bulb Planter from a Foot Pump ‘HE foot pump should have an inside diameter of at least 144in. The plunger is taken out and a hole bored through the base to ac- commodate the plunger rod. The handle then being fast- ened to the end of the rod, a piece of I-in. pipe is bolted on to the part which nor- mally is held down oc by the foot but nowservesasa TT handle. Theupper |{'! end of the pump |! where the cap was_ |}! removed is then |! sharpened on the |i th 2 FEET + Puy » tf: BS Se eee eee edge of the tubing so that it will enter the ground easily. In using this fk planter the pipe is l_ held in both hands Inverted foot-pump used and pushed into as a bulb planter the ground to the desired depth, which for bulbs is about 5 or 6 in. The wood handle then rises and indicates the depth of the hole. On with- drawing the pipe from the hole a solid core of earth is left in the end of the pipe which may be easily expelled. Popular Science Monthly The advantage of this planter is that it leaves a hole with a flat bottom and also does not compress the earth as in the case of a pointed stick. The maker of this has put in several thousand tulip bulbs with it in dry hard ground very satisfactorily. Substitute for an Automobile Hub-Cap A PIECE of inner tubing approximately 6 in. in length will serve as a ready substitute for a lost hub-cap until a new one can be provided. Should such a cap be lost there is great danger of the dust and grit collecting on the inside of the hub and causing damage beyond repair to the ball-bearings within. The piece of tubing is held to the hub with the aid of wire wound tightly around it, while the other end is closed with wire to prevent the dust entering there—ADOLPH KLINE. A Drill of Self-Hardening Steel for Working Marble RILLING holes in marble is very wearing on tools. | L, mae os “Eee L i: Ps 6 3-CELL UNIT SERIES-MULTIPLE UNIT FIG.2 This diagram shows the ar- rangement of the cells and lead fillers for use where the battery is to be charged with a current from other batteries sulphuric acid—one part acid to two parts water. Be careful in making the dilute solution of acid. Always pour a small quantity of the acid in the water and stir vigorously. Never add water to the acid. The paste mixture should be about as thick as putty. As there must be different mixtures in each leg of the lead tube the other mixture is made up in the same manner except that yellow lead—litharge—is used instead of the red lead. One leg of each tube is stuffed full of the red lead mixture and its mate with the yellow. All of the double elements are treated in a like manner. In making up the smaller lengths fill half their number with the red lead and the other half with the yel- low; thus for the 24-series unit there will be two of the short tubes used—one filled with red lead and the other with yellow lead. For the 3-series, 8-parallel unit there will be 8 short pieces filled with red lead and 8 with the yellow lead. In either case force the paste in so that it will be pushed out through the FOR 24CELL UNIT MAKE 23 FOR 3-CELL UNIT MAKE 16 2 BEND IN THIS ~~ | MANNER FIG.3 Popular Science Monthly holes, then scrape off the excess so that it - presents a smooth surface. Before the elements are assembled they must be treated for charging. One method is to charge the assembled battery and then discharge in the opposite direction. This operation should be repeated four or five times. Another way is to lay the legs filled with the red lead in a strong solution of chlovide of lime, or a solution of nitric acid, or sulphuric acid—one part acid to two parts water. Allow the elements to remain in the solution until they are some- what roughened. If the latter method is used the battery is ready to assemble. This is very plainly shown in the illustrations. In building up the battery shown in Fig. 2 a single red lead element is placed in the end test tube and one leg of a yellow lead double element is introduced into the same test tube, the other leg being placed in the second tube. Continue by using one more double element and finish with a single yellow lead element. This makes each tube with one positive element and one negative, and one unit of three cells is complete in the series. The other 7 units are built up in the same manner. The illustration Fig. 1 shows plainly how the 24-cell unit is made up, starting with a single element and finishing with the opposite single element, the inter- mediate ones being filled with the double elements. Two binding posts are used on the 24-cell, as shown. The screws are passed through the frame and through a hole in the end of the element. This is plainly shown in 1") : ; 43 5" tls $ = FOR 24-CELL UNIT MAKE 2 vs DRILL FOR INDING BEND IN THIS poe MANNER FOR 3°CELL UNIT MAKE IG FIGAa The elements are made of lead pipe cut to the right lengths, bent into shape for entering the cells and drilled for holes. Each tube has one positive and one negative element B, Fig. 1. For the 3-series, 8-parallel unit there are required 16 binding posts, two for each unit.. The posts are fastened in the same manner as for the 24-cell unit. The reason 16 posts are needed is that the cells must be connected in parallel for charging 4 Popular Science Monthly and then disconnected and connected in series for use. ne The electrolyte is made of a mixture of - sulphuric acid and water. Commercial acid of about 1.835 specific gravity should be diluted with clean rain or distilled water. Mix the solution in some kind of a glass or glazed crock, using the proportion of 1 BATTERIE: yv ps of primary batteries are con- nected in parallel and eight of the storage units part acid to 4 parts water. The resulting mixture should be about 1.180 specific gravity. Always pour the acid into the water in a very small stream, stirring vigor- _ ously at the same time. When the solution has cooled pour a sufficient quantity into - each tube, making the level come to within ¥% in. of the top of the tube when the elements are in place. In usual practice 40 to 60 ampere-hours _ capacity is allowed for each square foot of positive plate, measuring both sides of the plate. The thickness of the plate, unless great, is disregarded. It is well to know that the electrolyte penetrates only about 1/16 in., so that any excess of in. in the thickness of a plate is solely for mechanical strengthening of the plate and is useless in an electrical capacity. As the elements of these batteries are round, only the surface can be figured. The tube being 3% in. in diameter and 5 in. long makes a surface area of about 6 sq. in. In allowing 50 amperes per square foot, the ampere- hour capacity of one cell of this battery will be about 2. The average charge or discharge voltage is about 2 and the watt- hour capacity of each cell will be 4, thus making a 24-cell battery a 96-watt-hour capacity. While it is possible to draw more current from the battery than is rated, yet it is not advisable to do so, as that ruins it quickly. Each cell of storage-battery, regardless of its length, width and number of plates, will give after a full charge about 21% volts, and the voltage required to charge any number in series is equal to 24% times the number 949 in series. Thus, the 24-series battery, — Fig. 1 (since they are all connected in series) will require 60 volts. In the 3-series, 8- parallel battery, three cells are in series and the voltage will be 74. Usually more voltage than is actually necessary is pro- vided—about 1% to 5 volts per group. This extra voltage lessens the danger of having the storage cell discharge back into the charging source, the voltage of the storage cell exceeding that of the charging source. The 24-series battery requires about 62 volts and the 3-series, 8-parallel battery requires 8 volts. To charge a storage-battery with its maximum ampere-hour capacity—that is to say, to charge an 80-ampere hour battery with 80 amperes for one hour—would probably ruin it. The best rule to follow is to charge at the 8-hour rate. Thus a battery may be charged in 8 hours, which is the normal rate, or it may be charged in 7, 6, 5 or even 4 hours. In charging this battery the 8-hour or normal rate is de- termined by the cell capacity divided by the 8 hours, which would equal 25. That is to say, each cell is to be charged with Y{ ampere for 8 hours. The 7-hour rate is 2+7, and so on; but under no circum- stance should this or similar small batteries be charged at less than the 4-hour rate. Another good rule to follow is to allow a charging rate of .04 amperes per square inch of positive surface. It is apparent that the foregoing methods of calculation can be used to find the capacity and the charging rate of any size storage cell in common use. The resistance necessary to be placed in DISCHARGING 7 cd so SSN ca i as i TOAUDION J When used in a discharge, connections from the battery binding posts are made in series series with the battery on a 110-volt direct current main to lower it to 62 volts, the amount necessary for the 24-series battery, will be 192 ohms, for the normal 8-hour rate. In using current from a 220-volt direct current main the same procedure may be carried out to determine the re- sistance necessary to reduce the current to 62 volts. This will require 632 ohms for 950 the 8-hour or normal rate. With the 3- series, 8-parallel battery the most con- venient way is to charge it with bichromate batteries. These cells are cheaply and easily made of zinc and carbon scrap. They have a potential of about 2 volts and are high in amperage. Connect the two groups of 5 in series and place the two groups in parallel. Also connect the 8 units of storage-battery in parallel and connect with { + NOV MAIN ie FUSE ~ y 192 OHMS + os afafoalalafela}alaly}afala ala} falualayola| CHARGING ON 110 VOLT MAIN TO AUDION © orr FIG.7 When the storage-battery is used on an audion it is necessary to supply an end switch the bichromate batteries. Be sure to con- nect the zinc element of the bichromate cells with the negative of the storage- battery. This is shown in Fig. 5. This method of connecting the storage cells in parallel series is only for the purpose of charging. When used on the discharge they must be disconnected at the binding posts and connected in series as in Fig. 6. The cells during the charge should give off gas. Toward the end of the charge they should gas freely. A failure to gas is a sure sign something is wong. An insuffi- cient voltage or a short circuit in some one cell may be the trouble. When the negative begins to gas freely, or when the electrolyte turns to a milky color, it is a good sign that the cells are charged. A slight overcharge will do no harm. An overcharge is fre- quently used to clean out the elements. The battery fully charged will give a voltage of about 60 when connected in series. To provide the most efficient volt- age for an audion it is necessary to supply an end cell switch, as shown in Fig. 7. The voltage will soon drop to about 50 where it remains practically for the life of the charge. Do not discharge to a lower voltage than 42. A light charge should be given every two weeks. Popular Science Monthly - A New Wireless Station on the African Coast NEW wireless station has been erected on Cape Juby, on the African coast. In cases of need at sea the service is avail- able for ships in distress. As the installa- tion on Teneriffe Island is less than 100 miles from the Cape Juby plant, communi- cation with the Canary Islands is possible and, through them, with the Spanish mainland. Cape Juby is a sandy and practically barren ‘projection into the Atlantic Ocean some 67 miles from the Island of Fuerteven- tura of the Canary group, and in the same latitude. It is a part of that section of the western Sahara which extends along the Atlantic coast and connects the Mogador district with that of the Rio de Oro. The last named was recognized as Spanish territory by the treaty of Paris of 1900. Water is very scarce on the cape, although it can be obtained in the ravines by sinking wells. The interior region is said to support great numbers of sheep and to produce excellent crops of wheat, barley and corn. The ocean fisheries at this point are very abundant. A Light Signal to Designate a Blown Fuse HERE there are a number of fuses on one block and the block is placed in a dark corner, a blown fuse is hard to locate without a light or pocket flashlamp. To eliminate the wiring for a lamp and have a light ready to locate the burned-out fuse the arrangement shown wastinstalled. Each of the fuse-cartridges in the block was shunted through a low candlepower lamp. Such a lamp will not affect the rating of a \\ y SA LAMP A low candlepower lamp glows when the fuse is blown and until another is installed fuse to any extent and will not glow until the fuse is bloown.—JEsstE C. HASKELL. Ee ea ene) ON i cae ke ke en a a good joint can be made. Popwar Science Monthly Testing Bell Circuits with - Ordinary Dividers I. making tests on a bell circuit it is usually necessary to remove the insula- tion or make connection only where the wire is bared; however, the method illus- trated here can be employed without harm to the insulation. An ordinary pair of dividers is used, their points being thrust The points of the dividers are thrust into the insulation until they touch the wire through the insulation until they touch the wire within. When the divider-points are removed the tiny holes they made will close sufficiently so that the insulation will be as perfect as before —Epwarp R. SMITH. Changing a Direct Current Bell into an Alternating One change a direct current belfinto an alternating one on which a step-down transformer is used, make the connections in such a manner that the two poles of the magnet go directly to the binding posts of the bell; next connect in series with a 32-candlepower carbon filament lamp or the secondary of a transformer and adjust the clapper spring AURELIO SIERRA, JR. How to Make a Solderless Joint on Wire T is difficult to make a good wire con- nection when solder is unavailable, however with the following method a very Scrape about 6 in. of the wire to be connected, making sure that all rust or grease is thoroughly removed, then twist the wires tightly together. A piece of tinfoil about 1 in. wide is then wrapped tightly around the twist. Be careful not to tear it. Then apply another layer or two of the foil and wrap it over with tape, so that no corroding substance or rain can enter the joint. Pull the tape very tight so as to insure a good connection between the tinfoil and the wire. Then paint with asphaltum. This method is only to be used in case of-emer- gency.—ALEXANDER V. BOLLERER. 951 Precise Resistance Measurement by the Voltmeter-Ammeter Method HIS article is intended for the every- day shop man and the average electrician. The measurement of resistance can be made very precise by the method given. Two important points are: To be sure that the instruments read correctly to .1 of one per cent, and to take ten or more readings for each measurement. The resistance for each reading should be computed and the average taken of the several readings for the final value. The theory of this method depends upon Ohm’s law: E=IR. The accuracy of the results depends upon the readings and the manner in which the instruments are con- nected with the resistance. A high resist- ance can not be connected in the same way as a low one. It is well to know whether to connect the voltmeter across the resistance, or the resistance and ammeter together. For this reason the nature of the sample should be studied before an attempt is made to measure it. For example, let a voltmeter be connected across a high resistance only. The ammeter in the circuit will record the current through both the resistance and the volt- meter, as they are in series with the ammeter. There will be a very small current flowing. If the resistance to be measured is greater than the voltmeter’s resistance more current will flow through the voltmeter than through the resistance. MAIN LINES (V} R PY NN V/V MAIN LINES 4 @) WV) NN Diagrams showing location of ammeter in line for measuring resistance accurately In this case (problem 1) the ammeter should be connected in series with the resistance. The voltage drop across the ammeter is very small compared to that in the resistance. The per cent of error will be very small when measured. Now consider a low resistance with a large current flowing (problem 2). First, notice 952 the connections in first diagrams. The ammeter will read correctly, but the volt- meter records the voltage-drop across both. This arrangement is very much in error because the drop in the ammeter is greater than in the resistance. -In problem 2 the voltmeter is connected across the resistance only, as in second diagram. The current flowing through the voltmeter will be very small compared to that flowing in the resistance. The per cent of error in the ammeter is small. The voltmeter in the connections shown will read correctly. A simple problem may serve to make clear the described method. What is the correct resistance of a 40-watt lamp? The ammeter is a milliammeter, resistance of .045 ohm. The voltmeter has a resistance of 15,000 ohms. The voltmeter reads 110 volts and the ammeter .3636 amp. SOLUTION: Problem 1. VOLTMETER AcROsS RESIS- TANCE. The current through voltmeter, by Ohm’s Law, equals 110 =.00734 ampere. 15000 The current through resistance equals -3636 — .00734 =.35626 ampere. Per cent of error, -0073 Se AS per Cent, -35626 The voltmeter records correctly. Problem 2. VOLTMETER ACROSS RESISTANCE AND AMMETER. Voltage across ammeter, .3636—.045 =.1638 volt. Voltage across resistance, 110.0000 — .1638 = 109.8362 volts. Per cent of error, .1638 =.149 per cent. 109.8362 The ammeter records correctly. The ammeter in problem I reads too high by 2.43%, or about 1.51 ohms. From the arrangement in problem 2 the voltage reads too high by only .149%, or an equivalent of .0595 ohms. From the foregoing method a rule may be summed up as follows: When measuring a high resistance, connect voltmeter across resistance and ammeter both; when meas- uring a low resistance, use voltmeter across resistance only.—T. E. MARTIN. _ Popular Science Monthly Increasing the Efficiency of the Poulsen Arc Generator ig THE past the Poulsen arc generator of undamped or sustained waves has usually been used directly in series with the antenna in which it operates. The effi- ciency of this arrangement is variously stated as from 15 per cent to 50 per cent, depending largely upon the constants of the circuits and the details of design of the arc generator itself. The wide use to which generators of this type have been put in the past few years, in the United States Navy and elsewhere, - toward main- taining the highest effi- 2s 2 ciency. By the Hen | Se addition of ax condenser and rs oe inductance cir- cuits it has —7 been found possible to in- crease materi- ally the output of a single arc oscillator, and some results have been secured which would appear most surprising to those who are familiar with only the older forms of the apparatus. United States patent number 1,179,353, issued in 1916 to L. F. Fuller, shows one method of increasing the radiation or antenna current produced by an arc generator. As indicated in the figure, the only material change is that of adding the New arc circuit which increases the radiation two condensers I and 2. The first of these is placed directly in series with the arc 3 (which is supplied with power through the leads 4 and 5 in the usual way), and the second is shunted about the arc and the first condenser. Above the are and shunt circuit is connected the loading inductance 6, with a small portion arranged to be short- circuited by means of the signaling key; the high potential end of this coil is led directly to the aerial 7. The capacity of the two condensers is adjusted by trial, and depends upon the size of the antenna and the power of the arc. When the best values are used, the antenna current is often more than doubled without using any more power than normally. has caused a 7 good deal of study to be put = upon the sys- Mea a tem witha view ws, ase —_+_+ Ae id eh ee ae Popular Science Monthly _ The effect of the added condensers is to reduce the effective resistance of the aerial circuit. In the old lay-out all of the an- tenna current passed through the arc itself, and this of course occasioned large resistance losses. In the new arrangement the larger part of the radiation current passes through the shunt condenser, which has a much lower effective resistance, and the wasted power is greatly reduced. By shunting the condenser 1 with a circuit containing inductance and resistance in the proper proportions, the impedance of the arc circuit is still further increased and still more of the main antenna current forced through the shunting condenser. This causes still further gains in efficiency. With a 5 k.w. arc the antenna current has been increased 100 per cent by making the condenser I equal to and that of the condenser 2 twice the capacity of the antenna. Using a 50 k.w. generator, the current has been pushed up 74 per cent by suitable adjustment of the condensers, and then additionally increased I1 per cent by adding the shunting circuit of inductance and resistance. It is important to keep the inductance of the leads 4 and 5 very small. It would appear that circuits of this sort should be of considerable value in arc working, for not only is the efficency of the system markedly increased but the tuning of the system is made much sharper and difficulties due to the radiation of extraneous wavelengths are cut down. Making a Tuning Coil Slider with a Good Contact making up wireless receiving equip- ment it is often necessary to have a slider which moves easily and yet makes a good electrical contact. The following de- scribes a type which has been used with satisfaction. A piece of sheet-brass 1/32 in. thick and 34 in. wide is needed. The length depends on the size of the slider rod, but the dimensions given are for rods 5/16 in. square. Cut the brass strips to size and bend the square corners 5/32 in. on each side of the middle. Bend two other square corners 5/32 in. from each end. This gives a rec- tangular tube 5/16 in. wide inside measure- ment and about % in. high. There is left a 3/16 in. space after the rod is in place. Place the seam at the top and solder a brass strip 5/16 in. wide and 1 % in. long, lengthwise of the tube. Bend the ends as 953 shown in the sketch so that they will exert considerable pressure on the rod when it is inserted in the tube. Drill a hole for a small machine screw through the spring and tube. On the opposite side solder a phosphor- bronze strip which should be bent, as a al ee — = Se a aes Fan PHOSPHOR BRONZE ‘A slider made of sheet brass and a spring to make perfect contact with the coils of wire shown, to make contact with the winding of the primary. The length of this strip and its width at the point of contact will have to be determined by the builder. It should be long enough, however, to provide sufficient pressure and still not catch on the turns of the coil. For a handle the hard rubber grip from the generator crank of a magneto telephone is satisfactory and may be attached to the slider by means of a machine screw and nut, the screw passing through the hole which has been already drilled in the tube.—D. R. LEwiIs. A Simple Experimental Spark-Gap in a Case BASE, A, is turned out of wood on a lathe and then given two or three coats of varnish. The inside diameter of this base should be just large enough to permit the glass bell jar Btofitsnug- 4 spark-gap inclosed ly in it. in an air-tight case An ordinary spark-gap is mounted on the base and the connections brought through the base and sealed to prevent the leakage of oil. Enough good transformer-oil C is then poured into the base to cover it 14-in. thick, and the bell-jar is placed in position. This makes the gap air-tight and, by reducing oxidation, aids in producing a humming tone in the receivers. 954 Increasing the Efficiency of a Receiving Outfit H. RENDAHL’S U. S. patent No. e 1,175,472, recently issued, shows how a crystal detector may be coupled to a tuned receiver in such a way that the sharpness of tuning can be changed with- out affecting the resonant frequency. In older methods of coupling the detector to The antenna is connected with the ground through the load coil and transformer primary the resonant circuits, any change in the transformer leading to the detector caused a change in the tuning also. Thus, when the detector was tightly coupled for weak signals with moderate selectivity, 600 meter waves might tune at 40 degrees setting of the secondary condenser; while if the coup- ling were loosened to tune more sharply the same wavelength might be tuned at only 30 degrees. This inconvenience is eliminated by the use of the arrangement shown in the figure. The antenna is connected with the ground through the variometer load-coil V and the transformer primary K. The secondary K, has in series with it the tuning condenser C, the loading inductance L, the tuning variometer V2 and the coupling variometer V,. Across the coupling variometer is con- nected the primary P; which has very tightly coupled to it the secondary Px. The detector D, telephones 7 and blocking condenser B are connected as shown. Coil P, may be wound in ring form as a layer which lies directly between two other layers connected together to act as coil Pz. When the coupling is as tight as in this case the primary winding acts practically as a simple ohmic resistance, for its inductance is al- most entirely neutralized by the opposing currents in the secondary. The coupling of the detector to the secondary circuit is changed by means of variometer V;. With this at its maximum value of inductance the greatest amount of energy is fed to the detector, while when V, has minimum inductance the potential Popular Science Monthly across the detector is least. Since the coupling variometer is shunted by the al- most purely resistive coil P;, which is not of high resistance, its inductance is not effective in the tuning of the secondary cir- cuit. Therefore it is possible to withdraw the energy for the detector at any desired rate without having to retune. The loudest signals afe usually secured when the effect- ive resistance of the detector is adjusted, by means of V;, to a value equal to the effective ohmic resistance of the entire cir- cuit without detector. By the use of such an apparatus it is often possible to consid- ably increase the receiving efficiency of the wireless outfit. Connections for Vacuum Tubes to be Used in Wireless Telephony N THE illustration the microphone M is in an intermediate oscillary circuit, which is excited by a generating tube, V. The intermediate circuit is also coupled inductively with a three-electrode tube of large dimensions arranged for amplifying the oscillations occurring in the microphone circuit. By adjusting the steady potential acting at the control electrode of the second tube it is possible to arrange that. uniform oscillations applied to it have no effect on the annode circuit, and then only the microphone variations are magnified. If this be done, the second tube may be made the same size as the first; or the micro- A ae Diagram showing connections for a vacuum generating tube to produce oscillations phone circuit may be arranged between the two coupled inductances belonging to the generating circuits of the tube V in which case the second tube will not be necessary. A New Rotary Variable Condenser A simplified method of construction within the scope of the amateur By R. U. Clark, 3d HE innovation which the author has worked out for building rotary con-° densers, consists in separating the fixed and movable plates the correct dis- tance from each other by means of a simple lead casting for each set. The instructions outlined herewith make it a simple matter to construct two excellent rotary condensers, at a small cost and with little labor. The tools and materials required are readily obtainable. The dimensions specified are those em- MAKE 11 OF NO.26 ALUMINUM MAKE 12 OF NO. 22 ALUMINUM Dimensions of aluminum, brass and card- board plates for making a rotary condenser ployed in making the complete condenser illustrated. Although the fixed plates in this view may appear rather far apart, as a matter of fact they are separated by only 5/64 in., and nearly half of the space between them is taken up by the rotary plates; also it should be noted that the greatest diameter of the condenser casting is but 344 in. In the completed condenser, the fixed and movable plates are separated only 1/40 in. which makes the instrument very compact. The fixed plates are 3 in. in diameter and 1/64 in. thick. The rotary plates are also relatively larger, in proportion to the size of the fixed plates, than is the rule in con- densers. The rotary plates are made of thicker material than the stationary ones in order that they may have maximum flat- ness of surface, and also that they may hold their trueness better. This makes it pos- sible to separate the fixed plates a greater distance, which is desirable for many reasons. In case the experimenter should desire to make the clearance of the plates less than specified, thicker rotary plates should be used. The space between the fixed ones, however, should not be di- minished. The tools required in making the con- densers are as follows: one coping or jig- saw, and one hack-saw; one 17/64-in., one -in. and one in drill; a small vise, 2 small clamps, a drill stock, and a flat file. These are practically the only tools abso- lutely necessary; however, certain con- venient accessories will be mentioned from time to time in the course of this article. The materials required are as follows: Two 3-in. round brass disks, 1/16 in. thick. One aluminum sheet about No. 22 gage, 12 by 9 in. One aluminum sheet about No. 26 to 28 gage, 12 by 9 in. Smooth cardboard or bristol board, 1/40 in. thick, and of sufficient area to make thirty 3-in. disks. Two pounds of lead. Two brass machine screws, round or fillister head, about 2 in. long by 4 in. in diameter, with nuts. One piece of fiber 2 by 1 in., and 3/16 to 4 in. thick. Eight flat head brass machine screws about 34 by 34 in. with 16 nuts to fit. Two hard rubber or composition typewriter roller knobs with long metal bushings. Four small binding posts fitted with flat headed brass bolts. Two old disk records, or ten-cent phonograph records. apab™ One round pasteboard box about 3% in. in diameter by about 114 in. deep. The first step is to cut the sheet alumi- num into 3-in. squares. This can best be done on a tinsmith’s cutting machine, or with bench shears, as when cut in this manner the thin metal will not be bent, and none will be wasted in clippings. When this has been done the thin sheets should be cut into 3 in. circles, and the thicker pieces 955 956 A into disks 2-11/16 in. in diameter. A tinsmith can do this on a circle cutting machine in a few minutes. Care should be taken not to bend these disks. The 3-in. aluminum disks B, 11 of which can be used, should now be clamped between the two 3-in. brass disks C, all edges lying flush, and a 17/64-in. hole drilled through the exact center of the entire pile. If held in a vise care should be taken not to bend the disks by using too much pres- i sure, also if pos- sible the jaws of the vise should be lined up par- LU Se allel to each other, to pre- Fee vent uneven pressure. The types of disks In case the and washers to be ; placed on machine screw experimenter desires to make his own disks from the aluminum sheets, it will be found a simple matter to saw out all the 3-in. disks at once, by clamping the squares between the two 3-in. brass plates mentioned, and following the outline of them with a hack-saw. When this has been done all of the disks can be put in shape with a file. After the center holes have been drilled in the 3-in. disks, and while they are still clamped between the brass disks, 6 holes Y in. in diameter should be drilled as near to the edge of the disks as possible. These can be equally spaced around the cir- cumference. The smaller aluminum disks are now to be clamped between the 3-in. disks of brass, in such a manner that the centers of all lie in a straight line. While held in this position a 17/64-in. hole should be drilled through these aluminum plates, using the holes in the brass disks as guides. Now through the entire set of plates just mentioned, four %-in. holes must be made equidistant from each other, with their centers 5/16 in. from the center of the 17/64-in. hole in the middle of these plates ~ as shown at A. All burrs around these holes must be removed with a flat file, - when the disks are separated. Popular Science Monthly Next, the cardboard sheets, mentioned under the list of materials, should be cut into 3 in. squares and drilled through the center with a 17/64-in. drill as shown at D. They should then be clamped between the smaller aluminum disks, say 5 disks on each side, and held together by one of the large machine screws mentioned, which can be passed through the holes in the center of the aluminum and cardboard. By sawing around the outside of the aluminum disks with a hack-saw, all of the cardboard squares can be sawed into disks 234 in. in diameter at one time. As soon as the above steps have been taken, 24 of the cardboard circles should be made into washers by sawing out the centers to form a round hole % in. in diameter. This can be accomplished with a coping saw in a very short time. When the work mentioned above is completed, the 3-in. aluminum disks B should be clamped between most of the cardboard washers, about 10 to a side, in such a manner that the centers of the washers and the disks line up throughout. By starting from the center hole with a coping saw, as in the case of the cardboard washers, the centers of the large aluminum disks can be sawed out to the same extent as the cardboard washers. If the instructions so far have been adhered to, 4 sets of plates and washers should be the result as illustrated. The 6 cardboard disks with the 17/64-in. holes are not shown in the drawing. All the rough edges and burrs should be removed from all parts with a flat file, due care being taken not to bend the metal pieces. All of the small aluminum disks when F The appearance of each of the two halves after being cut in two with a hack-saw completed should be perfectly flat across the surface when tested with a straight edge in several directions. way to straighten the plates which are warped, is to heat each one separately over a blue flame for a few seconds, taking care The best and easiest pate!) ok Popular Science Monthly not to melt the aluminum. They should then be stamped between a flat piece of marble, such as a table top, wash bowl top, etc., and a hard flat surface 3 or 4 in. square. A blow of from Io to 15 lb. with an ordinary hammer is sufficient. Two pieces of marble were used by the author to straighten the disks, with excellent results. The large aluminum plates do not need to be straightened unless badly warped. _The small piece of fiber, included in the list of parts, can now be sawed into two I-in. squares, and these drilled through the exact center with the 17/64-in. drill, and then bolted to the 3-in. brass disks, both pieces on one side, so that four -in. holes can be drilled in the fiber to correspond with those in the brass plates near the center. When this is done these four small holes in the brass disks should be counter- sunk with the 17/64-in. drill, on one side of each disk. In the exact center of the bottom of the round pasteboard box, mentioned under “materials,” a 17/64-in. hole should be urilled, and one of the large brass machine ‘screws inserted from the outside of the box. An extra heavy pasteboard washer 234 in. in diameter with a 17/64-in. holé in the center, should next be slipped over the machine screw and pushed to the bottom of the box, inside. This washer should be about %-in. thick. It should be followed by two or three of the thin cardboard washers which were not sawed out in the center. One of the brass disks can now be slid down on the brass bolt, the side on which the holes were countersunk facing up. Wire nails with their heads removed should next be placed in each of the four counter- sunk holes, points up; also two opposite holes near the circumference should have nails so inserted in them. - By placing the various disks and washers over the machine screw, and using the nails in the -in. holes as guides, a pile of parts should be built up in the following order: 1 brass disk, 2 cardboard washers, I small aluminum disk, 1 cardboard washer, 1 large aluminum disk, 1 cardboard washer, 1 small aluminum disk, etc., ending with the other brass disk, placed countersunk side in, and preceded by 2 washers of cardboard, as at E. The four center nails should now be removed, care being taken not to disturb the pile of parts, and the few remaining cardboard washers, with the small center 957 holes, placed on the machine screw, and held down tight while a nut is put on the machine screw, and turned down as hard as possible by hand, and one complete turn with pincers. Too much pressure should be avoided, as it is only desired that the parts should be held in place so as to lie flat against each other, without reducing _the thickness of the cardboard through The mold of wood which is clamped in place for running molten lead over the movable plates compression. A quarter sectional view ef a completed pile is shown at E. If all the steps indicated have been properly followed out, there should be a fairly uniform annular space between the pile of disks and the wall of the box. Into this space sufficient melted lead should be poured to cover the complete pile of disks to the top edge of the last piece of card- board after the 2 nails near the edges of the disks have been removed. The molten metal should be heated in two small pans or ladles for a short time after melting, and all scum and dirt removed from the top. When this has been done two streams of melted lead can be poured in simul- taneously, from opposite points near the edge of the round box. The lead should be run as quickly as possible without spattering. It must be kept going till the necessary amount has been poured. As soon as the lead has cooled the machine screw can be taken out and the complete casting removed from the box. When this has been done the stray pieces of lead can be cut from the top of the pile, so that the cardboard can be removed from the top as well as from the bottom. The four nails which were removed from the small center holes should now be re- inserted and melted paraffin should be poured into the 17/64-in. hole in the center 958 of the plates, after the bottom of this hole has been stopped up with a short plug. It will now be found a very simple matter to saw diametrically across, through the entire pile of plates, with a fine-toothed hack-saw. Care should be taken to make the cut run straight through the center of all the disks from the top to the bottom of the pile. The paraffin mentioned acts as a lubricant for the saw and prevents the central portions of the small aluminum plates from being bent. The dividing cut should run midway between the two sets of small holes near the center of the plates. As soon as the plates have been sawed in half and after the plates have been slightly Strips of brass used as bearings can be moved in or out and sideways for adjustment heated to melt out the wax in the middle the nails near the center can be removed. The small spaces between the plates can be ‘cleaned out with an old toothbrush, to remove any small metal shavings which may remain. Each of the two halves should be like the one shown at F. One of the machine screws can now be fitted with the two pieces of fiber men- tioned and clamped to one pile of parts, so that the machine screw fits into the semi- circular hole now left in each small alumi- num plate. The two pieces of fiber, which are held against the brass plates by the tightened nut, should be so positioned that the small holes drilled in them line up with the corresponding holes in the brass plates, which should now be filled with putty, and this should be smoothed off flush with the plates on the inside. _ wooden mold shown at G. Popular Science M onthly A semi-circular mold should be made by boring a %-in. hole in a strip of soft wood about I in. wide by %-in. thick, to within 1/16 in. of one face of the piece, and then splitting this piece in the direction of the hole through the center. The two halves are then finished by making a cut the full length of each hole, thus forming the In this view one piec¢ is shown in position at the top while the lower piece is tilted back to show its construction more clearly. When properly clamped in place this mold can be filled with melted lead, which should be poured quickly and run from end to end of the mold while pouring, or poured in a broad stream. The best results are obtained by heating the lead in a heavy ladle from which it may be poured; but in case a thin pan is used, the metal should be heated again for pouring after it has been melted. The illustration shows the lead already poured. It will now be possible to take away the movable plates from the fixed. Hang the parts between the jaws of a vise after the head of the machine screw has been sawed off, and the pieces of fiber and nut removed, using the machine screw as a support and lightly tapping both ends of the fixed plates simultaneously with a U-shaped _ metal or wooden bridge and a hammer. Considerable care should be taken not to warp the rotary plates by uneven ham- mering. Having separated the plates it will be © found a simple matter to remove the card- board washers, either by shaking them out or picking them out with a pin or needle.’ All of the plates should have their edges gone over with a fine nail file to remove any rough spots or burrs caused by sawing. The lead castings on the movable plates should be touched up also. Both ends of these castings should be filed down about 1/64 in. All this should be done with great care. — The two fiber pieces, which are to be used in pouring the center lead supports on both sets of rotary plates, can now be sawed in half, thus making four pieces in all, oblong in shape. split with a saw for a distance of 34-in. from oneend, makinga 1/16-in. cut, which should run parallel to the largest faces of the fiber. The pieces may next be bolted to the brass plates with the small machine screws, after the putty has been removed from the countersunk holes. The heads of These should be a ———oe | ‘ a sa em ah laa Popular Science Monthly these machine screws are filed down, so that they can be easily put in place and will rest flush with the surface of the plates. From a strip of soft brass 1/16 by 5/16 in., two 1-in., and two 2-in. lengths are cut. The ends of these, which should be cut squarely, should now be bent over, the short pieces once, and the long twice, to the extent of 3-in., and 14-in. holes drilled in the center of each little square hill thus formed. Now 1%-in. holes should be drilled near the flat ends of the long strips, and countersunk on the sides opposite the hills. A short brass strip should now be slipped on the short end of each rotary plate shaft, and a long strip on each long end, hills facing up asin Hand J. These pieces can be slipped into the channels in the pieces of fiber as shown, and then ad- justed by moving them in and out, as well as from side to side, till the rotary plates line up well enough to be swung into position between the fixed plates. The flat headed binding-post bolts can now be inserted in the holes in the ends of the long bearing strips. The shafts for the rotary plates should be sawed off so as to extend 4-in. beyond the top bearings, and the metal bushings on the composition knobs drilled with the 14-in. drill to a depth of %%-in., unless they already fit the shafts, as in the case of those bought by the author. Those knobs should now be placed on the shafts and adjusted to such a position that the fixed and movable plates will, when the knob bushings rest on the top bearings, be equally separated from each other, when in the full capacity position. Now tighten the set screws in the knob bushings and adjust the upper and lower bearings little by little, until the centers of the fixed and rotary plates lie as near as possible in one straight line, without causing any of the plates to touch. When the best adjustment possible has been obtained, the nuts on the small machine screws holding the fiber blocks should be turned up tight, and the ends of the lower sets of screws sawed off flush with the nuts. In case a few plates still touch slightly in one spot or another, they can be bent a little by hand, by pressing with the thumb-nail. All of the plates should swing in one direction without touching. The strip bearings should not come in contact with the fiber- support bolts. ‘The two phonograph records should now be marked with a compass on the smooth 959 side for 35%-in. circles, which can be cut from them by following the lines with a pair of tin-cutters, or, if thick records are to be cut, with a hack-saw. The edges of the small disks formed should be made smooth with sandpaper. The center holes in these disks can now be enlarged to accommodate the knob bushings, and three %in. holes can be drilled in each disk to correspond in posi- tion with the small machine screws passing through the fiber-bearing supports, and also through the ends of the top bearings. Similar holes should also be drilled 3% in. from the edges of the composition tops in line with the center and bearing-end holes. With the knobs removed, the condenser Two phonograph disk records are marked with a compass and placed on top of the condenser tops are now temporarily fitted to the condensers. Using the holes nearest the edges as guides, drill 14-in. holes in the lead castings till the brass plates are struck. The bottom screws from a set of binding posts should now have their heads removed, and be screwed into these holes in the lead, making their own thread. They should then be fitted with a pile of small brass washers, equal in height to the top part of the nuts on the bolts passing through the fiber. To complete the condenser units the tops should now be fastened on, smooth sides up, and held in place by nuts on the two center bolts on each unit and on the two binding posts, as shown at J. The composition knobs can now be properly placed on the shafts and held in position by tightening the set screws in the bushings. Suitable scales, pointers and stops can be supplied to please the fancy of the individ- ual. The instruments are then ready to be mounted in the most convenient manner. 960 An excellent oil-tight case can be made at small cost from an aluminum cup about 3% in. in diameter. Glass cases can be made from large paste pots, oil-cup glasses, etc., or if desired complete composition cases can be purchased ready made. When mounted in any cabinet set the appearance of the instruments in question can be made to equal that of any condensers made. The maximum capacity of the condensers described is approximately .008 microfarad. If these instructions are carefully fol- lowed, the results will be very gratifying. There are many minor points brought out in the description which represent several months’ experimentation on the part of the author. Although slight variations of con- struction may appear feasible, it should be borne in mind that such deviations should be attempted only with the idea of experi- mentation. In order to do anything right the first time, it must be done according to rule. Experimentation often means de- struction instead of construction. The total cost for materials used in making two condensers by the above method should not exceed $1.50 exclusive of cases. The time required may vary from 6 to 20 or more hours. Tests should be made for short circuits with head-phones and a battery. An Improved Method of Aerial Construction HE construction of an aerial is greatly simplified if the wires are cut equal to the length of the aerial proper, plus the length of the lead-in, and connected as in AERIAL the drawing. It is understood that this represents but one wire of the aerial. As many may beusedasrequired. The chief advantages of this form of con- struction are that it requires no_ soldered joints, since the wire is in one piece from the lightning switch to the top of the aerial; that it has no sharp corners to start brush discharges, and that the lead-in has very nearly the same current carrying capacity as the aerial, since it is made up of exactly the same number of