fy joatetcieoeys inpvmannemeseensinsreyeroieeee a 0 a a 9 tptenindintermir roam, woe ans. ape, Fg og OM Or ety em, my om a ? 225 West ee Street ~ Volume 91. tir December 1917 New York ; * Capyricht, 1917, ae ems MODERN PUBLISHING COMPANY soe All nights reserved « Popular Science Monthly ea a et INDEX Volume 91—July-December, 1917 \ Rese Ys PA pera Bi, oN So mR ae 300 A Plumbing System for the Farm Residence... .. 305 Watering Plants Dro hag RIEO c peurees.4 889 Reducing Packing Costs in Handlin Telephone Sets 908 A Telephone Conversation May Be Almost “‘Pri- Wate NOWeUs YS 650.5 0s cae cx el veces abo s 913 ———— Conversation Made Easy by a New De- er Chareian Storage Batteries with Direct Current. . 947 Simple Method of Making Storage Cells........ 947 Auto-Transformer in Headlight Circuit on a Mag- Fr MOUS SS we ds eo a bbe CRA WS 6 wep ah cake eis 6 HOUSEKEEPING MADE EASY Save Your Bottles. A Shortage of Jars and Cans Is ‘Threatened = £862.45 she cies ics SR Not Even the Space Underneath This Desk Is BSCE ss ciel dss ace ea tes & icc Hee A Machine for Ironing Stockings............... Household. Appliances. .........-.e0cceeeeees 52-53 A Tea-Making Machine............02.ceecee-e Using Your Player Piano as a Vacuum Cleaner. . 72 = ing the Apartment Telephone into a Pay- When-You-Call System................+.-- 86 u Desire... 87 Combining a Strainer with the Bung eg a Barrel.. 90 Making the Kitchen Range One Hundred Per Cent Effoient 505d ev deleiae oe 8 11 A Clever Bottle-Opener.............c.0ceeeeee or eave Kitchens to Solve the ‘‘High Cost” roblems. i. 5. 6. sce nd Uae oe ee 198 Children Ras Write on These Walls Without Fear of. Punishment... 6.0.2 5 655 6 cc yee eeu eee 4 An Electric Fan Runs Without Electricity....... 217 Household Appliances... .........00e-ee0e> 238-239 Keeping Out Flies When You Open the Door.. Household Bookless Bookkeeping on the Poker- Chip, Principle.) 20 53..300 0 i725 234 ee Put Your Flowers Outdoors on this Adjustable Window Shelf 2.0558) 28. 0.6 Sy we 271 Hangin: Docks Cloth for Wall Paper......... 283 A ee le Deck Revolving Clothes Hanger for a iilees’ Refrigerator Using Evaporation for Cooling 289 Sterilization Is the Essential Factor in Canning Vegetables... j:...6 0 a3 A ee The Burlap Coolers os 305.) Ga eee Scrub Your Walls by panne Housekeeping Made Eas . An Approved Smoker's k s Kitt. 44 sbedd. ae A New Attachment to Held the Trousers in Place 420 A Handy Clothes Closet for Your Vacation...... 424 The Clam-Shell as a Decoration. .............+- 435 That Bit of Butter Left on Your Plate—What Becomes of Jt? ; 6.256 200 bes Sse haw pees This Vacuum Cleaner Is Used Like an Ordinary FOOM 46:55 456 as 6 sed Satale 010 Suid ge Housekeeping Made Easy .............-.+-- 552-553 Fronacaie Spot-Remover Works Like a Scrubbing rush... O00 6 eo ee TA ee eee An Owl with Eyes of Scissors sa Backbone of Paste 576 You “- Roll This Can Without a the Gar- Ce rr a) Sending the’ ee to the Laundry Through a Glass- ined Chute ¢ 650.005 695456050550 dee 664 The Full ions Pail. f6 202 000 30. 0 eee 669 An Accommodating Gas Stove.............-+-- 70 What to Do with That Wiioninn Umbrella...... 671 Keeping Your Neckties Smooth................ 672 New Can-Opener Which Does Not Destroy the Can 679 Housekeeping Made Easy. ..........000--55 694-695 A Necktie Rack... 5 6 ..ssi02355+%553Ueat eee 702 Cook Over the Gas Lamp..................2-: 721 Making a Window Seat Out of the Radiator. .... 725 Dry Your Fruits and Vegetables at Home....... 736 Carry Your House Key in Its Own oa a a stalers 736 The Kitchen Cabinet Up-to-Date. . 2 ee ook Puls eee The Temperature Alarm... .).°. 0. + ..ca5 ee 47 Kee ing the Shain peony Soap Suds Out of Your Storing Ni Needles and Thread in the Handles of CISBOTS soos) 6. G5 sda ws lg s Wns ey epee 828 Solvin. Kitchen itewsney Electrically... ....... 830 Abolishing the Garbage Can... ...:::....5.2-4-- 833 Rocking the Baby Fore and Aft. ............... 842 New Shoe-Polishing Kit: ...........2..+.02000- 857 improved Office Appliances............-. ile 870 Electric Fish-Scaler ¢ o.oo cee. oes viees nee 873 aby’ 8 Wheeled Dressing ‘Table. . .\oc>3 2 eae 877 Pte TS oo 2 PS Py orn 890-91 A Pelican in our Wardrobe to Hold Your Coat.. 904 Want to Goto the Attic? Just Pull Down the Stairs 912 INDEX TO VOLUME 91 ji MECHANICAL ENGINEERING Page Page ‘ Furnace Burns Soft Coal and Cleans Its Own This Typewriter Prints in Every Type and Lan. PT Sy Re ie ee oat Om arora 867 Set eR re oe Largest Direct-Current Power Plant............ 868 Is Your Typist a Sane Operator? This Machine mproved Mechanica! Appliances.............. 871 Wi Rs uso vig v.a\es cs xs Kloten tee @ wie Running the Oven by the Hot-Air Furnace...... 879 Big Steel Guns ad ‘aaa They Are Made.*..... 38 Making Flour from Pigskin. ................... 882 mrvicion 5 Rg RSE Baa Se eet den nanan anne Wood by Machinery.................. 885 FY Loriehin noes Danaea cca rece SROs 5 SA Slee 74-75 r Dredge That Served as a Drydock..... 893 A Coenen rawbridge Gate................ re ince to the Aid of a Shivering Manu- A Safety Coat for Workmen................... 96 Recep SMe 58g ao 35 88 ohk Ran eG OS 899 The Last Word in Fountain Pen Efficiency—An Doing the Work of Three Hands with Two, on a NS SEE TS eae 97 SONNET PO die 5 oak a Gaal En es oes on NS 95 A Portable Nail Distributor.................... 249 e U.S. Armies Prepare to Fight Germes <5: 106 The Evaporation of Water Drives This Remarkable i One promgetomes Will Run All the Watches in the oc ahs waa aia 61 A Small Sand Spreader Is Useful All the Year es Bt for Gold in Central and South America.. 264 The Seeproveee- ir EE Eee ee 265 The Efficient Garbage Collector................ 397 MIME URATNIED oon. 50 vs bale Vb e.0- 8s Sein ey. wa 398-9 A Machine for Reclaiming Scrap Material....... 410 Three Roadmaking Machines in One........... 421 A Time-Saver for the Repairman........... ... 425 Standardizing PY SOS ae oe ee ee a 440 Gear Wheels Made of Cotton.................. 517 Steam Jets Which Save Picsnads of Dollars in ee ATONE © IGMED: <5. Ae oie bake oc ce 523 Do It with Tools and Machinery............ 534-535 g Two Thousand Letters an Hour ...... 537 A Sabatcute for Forms in Concrete Roofs and vit An eae Washer? A AMON eis oP ecaceca bs 3 Vek % 544 ow One Furnace an Save a Big Slice of the MRE OMeOON TUS.5 6 fe be ce 4 wna oe se 564 baa sas oal Pvichly, but We Have Plenty to Saktae 4 Fortune Ovi of Cement Factory Dust.. 569 Blowing Stumps Away with Air................ 576 Welding Ten Miles of Pipe Tey a inka Rink. 584 aimee s with This Electric Drill Is Like Shooting a Let This Automatic Device Feed Your Envelopes . 595 The Overdriven Nail and the High Cost of Living. 543 Potted Plants as a Part of a Plumber’s Equipment 548 eecraw Bread Slicing Machine for the Commis- Fastening Motors to Ceilings Without Scaffolding 673 hone pon Coal by the Ounce or the Pound.. 686 A Device for Handling Rugs................... 699 A Simplified Gasoline Engine.................. 704 RRM MMNIG OT OUBOR 5 ois bi5 6s oe os bs wes si eek oe 705 nguishin: ames of a Gas Well. ........... 708 taal Reliaeell 2c 100....00 0. 718-719 The Most Ornamental Smokestack in the World. 734 How the Cellar Shut-Off Nozzle Originated ..... 740 Furnace crocpeedy Takes Care of Itself.... 742 Any Boy Can Build a Concrete Wall..... ....... 745 Whirling ewes Poles into Shape. ......... .. 749 Fire Doors That Close Themselves .......... ... 750 Sorting Letters with Gravity Chutes........... 752 A Valveless Pump for Gearset Grease. .......... 753 Cutting Sheet Metal with a New Machine....... 757 Handling Cotton Bales with an ame Head Trolley 757 — Giant ig. coal of the Austrian Navy......... 758 ee ee RPE Pn Pe ee eee 760 A New Siphon “That Starts Itself Without Suction SE ACRE S55 aT ao Salas 2 Hare eens 68 832 Turning choos on Their Seats Automatically.... 859 An Ice Helmet to Relieve the Fever Fasteat Walls: 115 Separating Russian mp from Vermin...... 119 hiropodists for the Army..................... 164 A Holder and vteilizer i the Toothbrush...... 205 eats Models of Mouths.................... 221 ingle First-Aid Dressing.................... 2 How Policemen Revive You When You Eeiae: 237 Pathe LER aki wide oO ES Pe WES PEI 263 Closing Up a Wound Without Using a Surgeon’s - piensa tin Cie bax S b oles. cide Teteala es 69 Feeding Conn on a Special Diet.:............. 270 Inducing Artificial Respiration with a Vacuum. 350 A Device for Supporting the Arch... ........... 5 the Bien tal Biveseanet 62. sats. bf wale 6440 24 ee 387 ene Diotar for the Human Jaw............ 408 A Treatment for Distemper in Dogs............ 434 If You Lisp or Stamme: Use a Mirror or Candle.. 484 Sean An for Our “Castle A Crutch Built on the Principle = the Rocking = The y suet Medical Museum’s Giant Skull. ...... 551 MOORS CDRAs olocica Sccn cS cet di seb S 564 A Huge Barber-Shop Sterilizer on Wheels ....... 583 This Death’s Yaa g Poison Bottle Will Prevent CE IRON 5 i f020 a ak pov's 0.555 763 ees. “ aws Open with a Spring.......... 464 say 274 Ejector for Removing Water from an Ash Short Cute, raps to Packing Houses.......... BOW Pel PAW eh wee nee gee ci (ihe ae ORD ET eek s 765 Mian MeO SOMME, oi eee ees eee 465 a Footboard Used as a Roller Board. 765 mh RMIMMMEMMUION eg Soe sc eek es 466 ew Way to Make a Hydraulic Test for Steam Rubber aes ie) in Handsaw Handle.........:..... 466 oe ee S PAINS S Bak Ge ES Ce ca eee esha ots 765 Using ecover Screw........... 466 Som mmo Abrasives: 2-0). 63s oes oa US 766 Sheet Metal roti: Simply Explained......... 467 Half-Soling Rubber Overshoes to Give Longer Wear 768 Clothes-Hangers Used for Handles in Barrel Covers 468 Simple Designs for Sheet Metal Working........ 769 Pocket-Knife ce waa Se i seh RES era 468 Table Leg Sliders Made of Shotgun Shell Wads... 770 ES ESS a ee ee eran 468 3lue Print Drying Rack to Hang Over Sink...... 770 Knock-Down Panne POEs See aad cues 469 simple Die Casting for the Home Shop......... 771 Passing Cigarette Smoke gf Handkerchief | 470 Expansion Shield for Screws Made of Sheet Lead.. 77} RIED MENOROIE, 25. ois.5 5 5b bie Saw ona so. a ssn 471 Painting on.Cemented or Concrete Surfaces...... an “Making and Using a Casting Rod.............. 472 T'wo-Speed and Reverse Patenranen for a Small Burning Glass Made of Watch Crystals......... 474 a” ES CRS BRET inn ese a enc one ae oe Burning a go TS oe ee eee 474 The cigs A Caused by Running Tires oy omg 773 corel Alo Designs in a Piece of Paper........ 479 A Jack to Keep Automobile Weight from Tires... 774 ayy tae wn Walls to Make a Porta le Summer Camera Focusing Screen for Fine Detail Work... 774 OD so er ee eee eee 4 Lathe Centers Used as a Clamp for Gluing a Box.. 774 epee: a Bic Pump for a Water Rheostat..... 601 Applying a Change-Speed Device to an Automobile A ge ike of Acid anne torempnseman Curve, G02 “Clutch... sco dcceedes suse oes be ceetcceses 775 New Acid Proof Brush for Soldering Flux ar Soltaning Carbon with Steam in the Automobile The u. erwriter's Knot for Flexible Cords...... SENGINO: ou ee PEE AA OK CO SA RAG Co tee ed 776 Testing for Trouble That Causes Poor yoo a Testing Gasoline Engine Compression........... 776 RR ca kde & i'r si soe 4 0ule\ d's * 6.9 0°00 610 Preventing Hinge Rods from Loosening on an Making a Practical Vacuum Cleaner............ 1 MEOMOMNE FIGDU G it ess. cok wed wousae 777 Blackboard an pgranet to the Amateur’s Shop... 614. The Proper Camber for Front Wheels........ 777 a peerconting Thermo-Magnetic Motor........ 614 Making a Re-Winder for a Motion Picture Film.. 778 Undercoating for roteer to Hold Paint. 614 A Hard Finish for a Lunch Counter Top........ 778 Seoncen a Razor on the Fleshy Part of the Hand 615 A Storage House for Potatoes. ................. 779 Warming y Tents with Improvised Stoves... 615 A Paste gry oar for Starting Screws and Nails.. 781 Making » a Campfire Tent with an Awning....... 616 To Keep the Ends of Rafters from Spreading. 782 Preserving Flowers in Natural Colors with Wax.. 616 Making a Substantial Cardboard Pulley for elts. 782 How to Reline Your Automobile Brakes........ 617 ~~ An Insulator and Fire Protector for-a Stovepipe... 782 Cord Cutter Made from a Safety Razor Blade.... 618 A Solution for Electro-Plating with Aluminum... 782 ‘Temporary Repair on a Broken Lubricator Filling A Lead Pencil Sharpener with Dust Collector Box. 783 (NS ng its PSI AGE OSE en Ay ee ee 618 A Stain for Giving Wood a Brilliant Rose Color.. 783 Sheet Metal Leg rs ke the b Explained......... 619 na ea a Fast-! Pin owe Riveting)... 6666605 : 783 Ingredients ke the Best Kind of Glue... 620 Drawing Perspective Views............-.0--0.% 783 An “cari aay Sb | Made of a Barrel and Cask 620 Removin icteg Point oe a s tacclcons Center Drill. 784 Pedal-Operated Brake for a Belt Driven Motorcycle 621 we ‘Method of Joining Airplane Sections or Wings 784 Making a Soldering Iron Heater of Pipe and sdvigee s°621 Closet Rod Which Will Accommodate Several A ee Paint for Surfaces Exposed the ee Rae pepe ae Opeth re eee eae 784 Ee ae alla che aka dng, o x bao heya 6's Repairin pe oe Link in a Motorcycle Chain. 784 Clip for « Car ing Pipe in the Vest Pocket....... 622 Spr Wictacesehe on the Surface of Glass..... 784 arecins rocess for Glass Instruments and Modest H Home at a Modest Price. ..........2. 785 UMN UMTLE BOP Glos daha 'kie S70 o's. v oie ac ew'v vaio thebae Sheet Music Into Books............. 786 Hol the T-Square on the Drawing-Board..... 622 ~=s Testin, for Trouble That Causes Poor Automobile inder to Locate Landmarks and Signal nhabes ti OR ET RA Se On PP Re Eee 796 A Convenient Pivoted Card File for the Besk Chemical Flasks Made from pinay, Light Bulbs. 921 Methods for Finding a Chosen Card....... : 633 A Concrete Mixer Made Out of an Old Mower. 21 Piping Automobile Engine Exhaust Gas from Comic Photograph Made with Film Negatives. . - 922 PE MMMUMMS he sca sv vcce rss cvecke sess cevesrese 626 Protection Curtain for a Mechanic’s Work Bench. 922 Edging Flower Beds with Bottles............... 626 Testing the Strength of Norway Iron.......... 922 Repairing a Broken Test Tube or Beaker........ 626 Coating for Window Glass to Keep Off the Frost.. 923 Making and Using a Casting Rod.............. 627 Instruction Marker for Photographic Plate ..... 923 Making a Cabin Tent Out of Ordinary Sheeting.. 629 Drill Holder for the Tailstock of a Lathe 923 lolding Pa: on a Movable Sloping Desk-Top.. 630 Some Useful Hints for the Owner of a Phonograph 923 eeping Oil from V-Belt of a Motorcycle........ 630 The Balanced Aquarium for the ——, Care of Fish 924 Building a Model Air ee ARE ae toca 63 V-Block with Clamps for Small Drill Press....... 924 popeiring a Broken Link in a aff eal & Roller Making a Sprinkler Hose Nozzle for the Boiler Room 925 Hy A Sok Fee ee Re Fe oe ee tees ae Making a Gage for an Oil Storage Tank......... 926 Grou ing Sheet Music Into Books and Binding Finishing a Book Trough in Natural Wood. 926 ete bbe so Wiens at AUS wae Riga aie SS 0 An Individual Strap-Hanger for a Crowded Car.. 927 A Teeter Swing for Public or. Private Playground. 633 A Garage Air-Compressor Made from Automobile - An Experiment with Sulphate of Soda.......... 633 RE ion ova va SO Ad ts LA GASES DAE LCS TS 927 Cutting Brass Tubing Rapidly on a Buzz Saw.... 634 An Emergency Repair on a Leaking Water Bester 927 AW. t Built in Like a Dumb-Waiter...... 634 Door Catch Made of a Spring Shoe Tree........ 928 Improvi Piano Tone by Making Air Humid.. 635 Reshaping Artists’ Paint Tubes for Refilling... . . 928 ‘Simple Camera Attachment for Photographic earing a Pack of Cards in Half with Ease...... 928 “ae ap re Bet arere aa ee 635 Construction of a Bob-Sled. ..............045.. 929 Bracing for an Iron Pipe Fence Post............ 636 Boring Mill Tool-Holder pcr igi ing 5 ppeueive Steel 932 Attaching Linoleum to a Cement Floor......... 636 n Improvement on an old Jin. Be a ae 932 Casing for Carrying Tube sopenter eat vamege see News ow as a Substitute for “Chalk Talk Board. 932 A Silver Plating Bath and How to Use It........ 636 Treadle for an Aut bile Foot lerator...... 932 A Simple Toy Motor Run with Dry Sand Pe ee 638 oal Is Dear. Learn How to Moai 165 AER 933 Vill -INDEX TO VOLUME 91 Page Hand Bob-Sleds Made of Barrel Staves... . 9 4 ee Butt Mortises with an Ordinary Rabbet PSone Rafters for Gothic Roof Barn Construction 935 Fruit Jar Rubber Ring to Repair Bicycle Tire NEUE. Dias ees Seeh's od x whee Biva EO Ate ole ete The Proper Care of a Soldier’s Wardrobe........ 935 re roving the Qualities of Cheap Lead Pencils... 936 arrel Stave Iceboat 937 A Homemade Sight Feed Oil Indicator for an Auto- A Simple Method of Fastening Umbrella Handles 938 Simple Designs for Sheet Metal Working. ....... 939 Garden Hose Used as a Form for Cement Pipe... 941 Eliminating Noise from Shift Levers............ repens a Scratch on an Automobile. ......... 941 How to Straighten a Warped Drawing Board.... 942 Making a High Gloss Finish on a Matt Surface Pig baanes. kind > bee wt latg iy a dare Maer Bite 942 protecting. Drawings on Drawing Board........ 942 Setting a Lathe Quickly for Taper Turning...... 942 Teeth of a Hack-Saw Blade Used for Spacing on Section: Liner ois) s scntieit.x $s Pale MI As wrehyeieee 946 How to Make a Secure Joint in Copper Tubing... 948 Things to Know About Lubricants for Machinery. 948 Constructing a Thermostat to shape peg puenare 953 A Coating to Make a Battery-Box Acid Proof . 954 Heating Sheet Hard Rubber to Cut Round Disks, . 959 bighting the Dash-Board of an Auto from the Side Sheet rs ere to Make a Packing for Steam Chests 960 RADIO COMMUNICATION “‘Silent Music’’—Recreation for the ca baby ry 28 Curious Circuit for Audion on a Wireless Set. 151 Conversion of Kilometers to Nautical Miles..... 151 An Fxpeienanta| Wireless Aerial Made of Zither a WAES io sacbs int d RICA GN Rit ie Oe a AE ia ROR To a the Ears Perspiring When Wearing Felephones < iaiaiis-s 9: vehaGing sb & Dahlen wiles 152 Mounting Tinfoil on Glass Condenser Plates..... 152 ow Germany’s Secret Service Wireless Stations Are Being Weeded Out A peryetat Detector Holder te Wireless Apparatus 155 spe: of B ony Moon and Season on Wireless in the A Sabb Aerial Spreader for Long Wires....... 156 Position of Wireless Waves Passing Over Land. 156 Cloudy Days Best for Wireless Wave Signals. 156 Vie geek the Tone of a Test Buzzer Used on Wire- Nee LOLOOROR sai s551 a esos oks Rraeiacd Gas Wee Meee 156 Simple Construction of a Rotary Gap Disk...... 156 Simple Solutions of Wireless Problems.......... 157 Magnetic Brake for a Wireless Rotary Gap Sigha aia 160 Adjusting the Detector of a Receiving Set....... 160 ow theyGovernment Seals Unofficial Stations .. 208 A Simple Arc Lamp Using a Thermostat Control... 308 Slow Acting or Sluggish Noise PCE ae eG rt eet 308 An Ingenious Wiring System for Two Inductive EE PATSLON IROL w: i6ck: ss nin whoo od wi ge eee eka ae 3 A Variable Condenser for a Receiving Set....... 3 An Amplif Ehoatrowptie. Radio Receiver..... 3 Treatin oo board Tubes for Tuners.......... 3 Strong Wireless Signals in Winter Time......... 3 A Testing Set That Does Not Use a Battery. | How the seme Inspectors Trapped a Disorderly 3 Pi wien Cae sh reid whe & rade ie cate ele eee aa How to Make a Kick-Back Preventer for Wireless YW tr Py Pe ee ee ry ee. A ee A Use for ded Cylind 1 Food Boxes..... 314 Variable Wamass Coil Using a Switch Instead of a Sliders 65 36 gata ak Ve eee Rha 314 America’s New Semi- Wireless System for Telephon- ing from Captive Balloons.................. A Polarity-Changer for Reversing Lighting Battery AEC T IEG 25 'cg taco Mies eipa 6(8. w Seo eee eo aia leain a eee ae Dormitory Beds Furnish the Essential for Antennas 316 An Insulation for Secondary Terminals......... Wireless Work in Wartime.................4-- 317 A Simple Fixed Ralisetment Detector........... 320, An Audion Battery Made of Medicine Vials... . . 441 An Easily Adjusted Detector-Stand............ 441 Page Wireless Signals Transmitted by Telephone. ..... 442 Fighting the Big Guns with Wireless............ 443 ioe ees School Bell with Wireless....... How to Make a Variable Condenser for Five Cents 446 Wireless Work in Wartime.................05- An Inexpensive and Quickly Made Detector... .. 450 Porat es the Strains on Aerials ee ee Sustained Wave Telegraphy Between the United States and Germany #2). 5.0.0.0 65 6:05 Se 451 Double Set of Receivers for Visitors............ 433 A High Voltage Lead-In Insulator Tube........ 453 Loading Coil in Series with the Secondary. ...... 453 A Ticker Interrupter Made from a Buzzer....... 454 A.Simple and Attractive Loading Coil.......... i] Transmitting Wireless Messages Underground ithout Aerial i020 i: ic 0s caesar 602 Sending Wireless Messages Under Fire ......... 603 Construction of a Rotating Arm for a Rotary Gap 606 higsany Work in Wartime... 0.3... |. teu 607 A Grid Placed in the Wings of an Airplane...... 614 Increasing the biieney of the One-Inch Spark Coil 787 Wireless Work in Wartime. . ‘ . 193 A Strong Gu ar -Wire Anchor for Aerial Poles... .. 797 A Magnetic Telegraph Key for the Wireless Operator 798 Ballast Weights for Antenna to Prevent Aerial from Overturnin The Marconi Company Sues the Government .... 913 Detecting Defective Insulators................. 914 The Human Morse Code... ...........000000:- 950 An Inexpensive Multi-Point Loading Coil. 953 Water Glass Gage for a Lead-In Insulator...... . 954 Wireless Work in Wartime. ............-2.2-0> 955 An Easily Constructed High Tension Insulator... 959 RAILWAYS This Railroad Crossing Cleans Itself and Eliminates ee ee ee ce rr ay Jolts 5 Attaskine Mail-Car Robbers with Deadly Fumes. 27 Owens Valley, California, Has a Freight-Car Hotel 87 Can the Railway Train Be Made Noiseless? . 92 Flushing Streets with Water Pipes on Trolley Cars 107 Street Railway Smoking Car...............+-:- 214 The Largest ‘Traveling Kitchen oie Co eae .. 224 The Biggest Locomotive. . 2.00.05 0iss ceeewscee 251 A Refrigerator Car That Really Works ......... 394 The Most Powerful Kore Ue in the World.... 396 Street Cars Pull ee OEE Be steers aon eraee .. 4ii A Sanitary Dinin: os Gr ewer ee 418 Solving the Car haveane Problem. <. 233,08. 40 ae 422 Lest the Engineer, Forget. .).|:. .-:ass <9 eee pene 436 Canning the Baby in a Super Sleeper.. ........ 513 How Print Butter Is Ship Peet as to - Retailer reap 519 Flagman’s Shelter House Built Like a Mosque... 551 Safeguarding Our Bridge and Railroad Crossings. . 565 Putting Driving Wheels Under the Locomotive T onde? 2.5 viv's cess ci tae ee ee useictis A Lift Deck for Automobile Freight Cars........ 592 A Lumberman’s Camp Which Can Be Moved from Place to. Place on Rails. 6... vise ce coke eee 598 Special Cars for Persons Carryin ng P rowan ea has 708 Loading Cattle on Trains in a New Way........ 723 Diminutive Electric Locomotives............... 738 How a Reiboed "itaa acts ee! Traveled Through ew York City 884 SHIPS AND SHIP BUILDING Why You Can’t Compare Ships in Tons........ 29 A New. Life-Boat 23.0.3. 00 65034. 0 60 Salvaging in. Armor. is: :..0): 6 iess0a ots ae ee Motor Attachment Which Prevents the Rowboat Propeller from Being Injured.............. The Latest Salvaging Device—An.Electromagnet. 113 An Electric Eye Winks the Smoke Screen During a Battle. cis Sau eee se ete b%.. 15 Practical Motor-Boati ing ep mee. «! wy alee 116 A Two-Million-Dollar Hospital Ship............ 206 A Ship with Six po | PR eee anya re | 209 The U.S.5.- "Regret iiss ch ak es ooh eae eae 212 New Type of Life Boat............ Sikes 4 ae 223 ee ee ee ee | INDEX TO VOLUME 91 ix . Page Page The Unbeaten “‘Constitution”................. 242 ~—‘Is Curled Hair Becoming Stylish in Japan?...... 26 The t Model of a Ship Under a Roof..... 252 hese Magnifying Glasses Are Worn Like Spec- Disgui Mihistartnice Oo Sea ier ee a 265 CELE at SS sald Ser aac Skane A BAIS, TS NR A Gi a ie 29 Giant Mushroom Anchors for Folding Buoys... 265 Making a Second “Self” for Dressmaking Purposes 48 a om RIL. 6. scene ¢asels Cia his ee bc aes - 275. Ingenious Toys Made by Soldiers.............. 57 My Bes cen SPAN SSOBED 575 oo os ca wins ee 297. _— A Hair-Drying F FOO. ee ene 61 NES Ds cig t oles Sev tes dee 393 A German Medal C ting the Sinking of A New. 1 fa Savin PMEROETN ak ibys Soe late 408 Gia EMUIRR TSR oe fc ois ok a eae alee 66 Practical Motor-Boating................0..0+: 426 .A Safety Chain for Your Pocketbook.....,..... 69 Making the River Drive a Ferry Boat....... . 432 Platinum Is Too Useful to Be Used as Jewelry . 69 The Graveyard of Ships That Passed in the Night . 520° A Twelve-Year-Old Inventor's Combination Um- The stag Is More Important Than Meals brella and Rain-Cape..............0000005 91 ES ere eae eae 52 The Straw fist for Storing 22 oe ss ees Soa. de 95 ts That PIP Nea Land and Water......... 525 Giving Convicts a Real Chance................- 98 — as Seapl arise and She’s Unainkebio. 529 This Pied Happens More Often Than You'd me stousebout-of Marble... 2. eee BAB) eB ivn ot e eere aay ig eit ee eps 101 Even a Battleship Wauld Sink If It Were Not Five Hondvad Indian Languages............... 165 NUN ed aca Wd'ic! Savin 9 ale s\e 4 is'als.0 ues vib a6 abe Mechanical Hair-Parter...:...........0000e00: 165 Shall We Build Concrete Ships? ................ pignt Cord Fastener: 2 ooo ches a ke on 166 = ine Terpeaced but Her a Plugged the Hole 369 Foiling the Pickpocket and Protecting Your Watch 167 — oe Storms to Mariners..........-....... 582 Use Your Natural Arm If a Craftsman......... 187 ard Ghip-of Che SOA; . oe. es ie ccs eee 645 A Helmet for Smoke-Filled meee SANE RDS cra he 199 Whee 's wrece with the Submarine.............. 682 A Chinese Composing Room.................. 202 Cast-Steel ae EIN ocak «ic wares s Soe 4s.s 690 Wire Hood for Protection foe ainst Mosquitoes.... 202 A Bungalow Takes a Sail Across San reget Bay 751 Teaching the Blind How to Write on Straight Lines 208 - Raising Su Fishing Village That Float Deadening Noise by Pasting Tar Paper on Floors 228 Sunken Ships with Collapsible. Air Bags.. 829 A Pencil with Nine Good Points............... 228 arries Engine in Its Fin.......... ...... A Novel Change Receptacle................... 233 oa a ele arber a op. re TAYE ELSA a eee s 1 oats Live on the Roof. . 2... oie eee SPORTS. AND. PASTIMES Cold Water Pipes to —_ a Room Se RAR, arf AB 246 Dickory, eactiry: Dock, the Mouse Ran Up the— Another I the Poli ’s ““Billy’’ 247 RENN eas Mus eres a ip eis eke A Fortune from Old "Racor Blades RoR EN OE AG ole 248 A i a sacha Basket for the Picnic Outing..... 31 Fifty-five Packages _ Chewing Sais for Everybody 249 A Many-Sided Bathing Cap................... 69 Wave Your Cane Fi gg ee aes ee PEA 249 This Board Will Help You Learn to Swim....... 85: An Accommodating Church—It Goes Wherever A Vast Fortune Is Chewed Up Every Year...... 103 Bee WMO ar ee airs hades Risk PE Sian wate es 260 Land Skates with Brakes and Pneumatic Tires. 109 If Your Pastas Thirsts, Give Him a Drink....... 260 ane the ce on the Rio Grande in Jamaica Wo. A Bettonhole: Watelt. 70 ee ee i ee ee 261 INE eer ga 5 Coo 8% oars s 0.0 kv lesb bo 190 An Automatic Revolver No Bigger Than Your Scraping « a “Baseball MOR ects erates Ossie ews 214 DEOL aie t Lk Une pee a Ee 262 utomatic Bait- asting Fishing Rod........ 226 The Rate at Which Food Prices Have Advanced... 265 The CRETE Stet cece ac ok ccree ke 227 The Dumb Turk. He Smokes Cigarettes......: 268 This poon Hook mee: IR MMMNO SS ee Othe toa 240 The Outdoor Trap for the Anti-Fly Campaign .. 271 Conquering Your Cramps Under Water......... Holding the Whetstone Where It Is Needed... ... 273 beg an Axe and Two Springboards He Chops His Going to College to Learn Wood Graining....... 274 poy Up a 120-Foot Free Pee cdeacss fw we 253 The “Swat the Fly’* Campaign Is On........... 274 BiG BOG ete Carrier... oe... eee cee ene 326 Collecting Old Newspapers.................... 280 Shooting Snapnin Milage Pies sek 368 «6A Pacee-t hak MM eS cars hoe wie 2 ch Soy gues 329 me of Pocket Billiards............... woes Ameena On WHOEIS. . 4°... i5 odiew lou cudeesees 348 purroriog the Fisherman to the Fishing Pier..... 392 Washing for Gold in the Guianas............... 349 An Amusement Park in a Nenont RAE Sacto 412 ee Lives in Government Surveys.......... 352 Hitching a Fishing Line to a Kite.............. 412 Cardboard Covers for School Desks............ 352 ciate Re Undertow Gatone It Catches the t More Fruit and Drink Less Water.......... 353 Deine pt ede ta > to d4.5 erie siue s se 431 Using a Dozen Different Inks Without Mistake.. 354 Pulling « and F Pushi pee te to Make the Swing Go...... 524 Making Mud-Highways................++-005: 362 Lowering the Life-Boats by Means of Gear- PEE SOS ESS AS Oe a Rr eer 374 ES ois wo ig Reg ks eek hss Go's 533 he Broomstick Periscope. .............+..+4+- 378 Put These Webbed Gloves on and Swim Like a Duck me WY: PAT HRIEED SO DOMORE? 5 Gace o's cs 5 tere pe hoe ee 378 Maltreating a Water Bottle to Test Its Strength. . TEsRees RE UMPEUN PIRES eg osc kw des piv oes 0 8 0 08 ole 384 Making a Mule Push and Pull at the Same Time. 236 An Encounter Between Fire and Ice............ 389 A Water-Cooling and Purifying Pipe for the Fastid- A Heel Which Wears Straight................. 394 RS Se eae 90 The Candle Industry Still Flourishes........... 397 The Suitcase Talking-Machine py re eee em aN 644 PIGRt: inde OF FARIGUAG . vic cic 0 Scie cee easectvecs 397 American Boy’s Wagon................... 670 ag OE O00 aa ee a ae ar a 400 Looping the Loop in a Rocking oe ya pet eee 673 A Fire Hose with Ten Nozzles................. 408 Malin for Herring with a Windmill. ....... 724 A Waving Fla hag! b Seog Buttonhole. ........... 409 ing the Swimming Pool Attractive.......... 725 This Device Let Your Hat Blow Off...... 411 +4 Patriotic Tunes on the Air-Brake........ 737 Measuring the Wear GU POORON es a. Gai ca Oh wens 413 ; ng Comfortable Quarters for the Pet Snake.. 829 Goats’ Milk Saves Babies’ Lives............... 416 bene, of Alaska Held a Reindeer Fair......... 837 A “Safety First’’ Device for the Bill Folder...... 417 NS EG eres je see Experts Punch the Time Clock for Slow Stevedores 418 Watch-Case Revolver... ...........c0.cceceee 843 A Sh hrewd Marketwoman Made of Figs......... 418 NENT PUM og. sigs oe Shela o 8 tlc a 862-63 hat’s Become of the Breweries?....... ipaees 423 #® Christmas Tree Stand. ..............-....:. 874 A New Clock Scheme for the Daylight Saving Plan 432 A Jungle in a School-Yard................0..0. EE ae Se EGUIR EERE, co. 65's ose) bee ec eben cen 484 The Home-Made Ice Sleds of the Chinese Boys... 881 Fro GOURD COTES, 12. bien y Coes cecesa cst ews 514 A Toy Rpatt tor the Faciists:, 6. 3). sc. ss eek 883 Work the Typewriter Standing or Sitting. . 516 Novel Color Mixer for Teaching Color Effects. 888 Each o_o. Has His Own Telephone in ’ Thie A Billiard Table That Folds Up When Not in Use. 909 I i or fila hn. MEL eo ois Sicelad ou 516 A Mouse Spins Cotton Thread................. 912 A Pencil- Pen Without Wood, Rubber or Graphite 520 Winning an Athlete’s Laurels.................. 943 Ie OM CPG S ois eis nak Sn 8 o's Boe ee foe 522 It Holds = pert 6 Ss cies a acu? Sen : 333 n Japan the Barber Cleans His Patron’s Ears... MISCELLANY fopen About 150 Pounds Pressure to Break an The ieeest Straw Hat i in the World Is Yours If It nS DUP a eae ee oe 525 What Makes a Man a Criminal................ 526 x . INDEX TO VOLUME 91 Page Pa: Let ang 8: Be Your Meat Substitute........... 531 Flushing Sidewalks Without Disturbing Cars..... 710 How You Light Your Cigar in Italy............ 537 A: Self-Filling Pipe... .... . + <¢.ebenes Spee 717 The More ve ou Pay for Your Clothes, the More Iron Signs Give C Good Advice to Tourists....... They Suffer on the Clothes Line ............ 569 Showing House Numbers on Street Signs at Corners 725 And These Are Not Leather?..........4.+--4-- 571 Leather from the Sea.) ... os oan oa 3 726 Where Violin and Tennis Strings Come From.... 581 Why Anthracite Coal Lands Differ in Price...... 731 A Convenient Device for Keeping Your Razor This Kerosene Lam Has a Horizontal Wick..... 751 PRIRGRG SOLGAN 5 5B ocov ee 5 Bk sero b A elk Mac ae 584 Woodman, “pers hat. Trees? 6.03 vs ccactestbeeae 755 A New Zinc Product Which Is a Substitute for Tin- . A Device for Keeping Bananas Clean ........... 804 REN S O aiak cians Rk Gish Gis RM ceed eo eee 585 The War Price on Monke rr cSarr rit eo 804 To Keep Out Burglars Leave Your Key in the Door 591 A Badge Which Tells the the Story of Your Life..... 807 The Over-All Has Entered the Fashion Sheets. Fath The Largést. Ball: of -T-wiht dc <2 cee cee 824 Is This the Secret of Curious Finger Prints?. 1. 594 The Most Expensive Coat i in All the World...... 834 The Ivory Pie-Crust Trimmers of New England.. 595 How the “Ship of the Desert’’ Is Anchored When Pack Your Water-Proof in Your Bag.... ....... 596 the Caravan Rests. sog.y Bae The Mechanical Cigarette-Filler................ 646 Is This the Secret of the Earth’s , Magnetism. Tinea 843 His Drum Is Made of Human Skin and His pn mice for. Face Powder .3..0. inasied . ise 854 pet of a Thighhone «.°.:: ..s0Ndssetipiueleto beaten 647 A New Method of Lenco to Play the Violin... 860 Bho? Favorite Pocket-Knife of the Jackies........ 647 Protecting Your Shoes from Mud.............. Ee t the Indoor Air....... 664 A ‘Palace: of Corn...) 05 4s ¢ ca 3% 3/0 cco 874 F iltering the Snores Out of Sleep. ...........-.. 665 Wealth in Scrap’ Piles... i390 1.45 e20 eee 883 A Space-Saving Display Fixture................ 668 Wearing Spikes on Your Feet to Prevent Slipping How to Store Bicur to Prevent It from nang. 672 on Lee os eck inca 5. 0a te 0k dle ee De Efficiency as Applied to an Ink-Bottle Holder.... 678 | The “Complex Dinner’ Container for Long Trips. 900 ~ Fuel from Waste phe see RE ade oe ee 679 Pull Out a Cigarette and a Lighted Match with A Fountain Ink-Eradicator......... 020s eee 679 One Motion: « 5300.05 c0cke Gata ne ee oa eee You Can’t Spill Ink When Pouring from This Bottle 681 We Boycott the Chinese but Not His Hair....... Lucky and Unlucky Tel OCR CES Open a Stubborn. Knife-Blade, Throw. It from Holding Crowds at Store Windies tous eek 698 WOR eis Soa ws AD cha de 907 Dolls That Proclaim the Fashions............... 693 Ppa ee Lamp Posts Mark the Arrowhead Trail 908 A Novel Tobacco Fong Bib ek aide tein A ola niece 700 ~—s— Filtering Out the Harsh Tones from a Phonograph 911 : s instead, of Horsess. «6. ie:. «0 00:s sion pas ek 702 We Use Eighteen Times as Much Light as Did ad and Pencil Reraches Sd:ise Ae ha A 703 Our Great-Grandfathers) .. .3.25.. Josue eee 914 nN SBNTIODEL 4.0) 6,145 Hinis B corp syese 245 eae er Sere 704 Matches? Take One at a Time, Please. ....... 914 A Time-Saving Measuring Board............... 707. Sharpening Your Pencil Without Soiling Your _ Transforming the Bow Leg... 2... 05... ce eee ees 710 Fingers’. 6265 0% cie'e's Fa bY cine Fo pe ee 918 Rear Admiral Fiske, Naval Strategist ae Photo by Marceau z ee URTELERE DERG TEDERETEGEREREUATET A SY OURTCOTECOERUOOLTOANER OO OOHECURAPARUAEIAUOERAROUEOOLIOGUUAUOIIDHOOUENOADESOTIORTONOOGATINGUOOIOVSED “Permit me to express my admiration for the POPULAR SCIENCE MONTHLY in its present form. You are doing a splendid thing in making science really popular. The whole structure of modern civilization is built on physical science and its application to the mechanic arts; and the more successfully and widely we can utilize physical science, the higher a civilization we shall have. Your maga- zine is making a generous and powerful contribution to this end.” O,.. Froke The First Successful Fliers of Man and Nature About seven million years ago the first bird began to fly. Flight was merely gliding, and clumsy gliding at that, which developed from the about-to-be birds instinctively spreading their limbs when falling from trees or jumping up in exuberance of spirits. Notice how closely the lines and movements of the first living flier resemble those of the pioneer motor-driven flier behind it Popular Science Monthly 239 Fourth Avenue, New York City July, 1917 $1.50 Annually >» Ds came later than fishes and i) reptiles i in the evolution of life. But ~— what manner of creature was it that linked fish with bird? What was the first ‘that ever flew? Fossil re- ins and imprints have so far only | scant information -how the feathered de- ants of the fish or the rep- gradually came into posses- of ee: apa of flight. nc | this i is due, at least in the extreme remoteness hatever nee were before. The _ change was so radical that it re- quired millions of years by Na- 7 ture’s slow methods. _ Fortunately a single natural F ‘document has come down through Pi e ages which goes far toward explaining » mechanics that made the elongated mming fish or crawling reptile fit for aining, propelling and balancing it- self in the air, and this document, as it ‘happens, also establishes a most curious _and interesting parallel between Nature’s experiments in flying and those funda- etal experiments by Professor Langley the Smithsonian Institution in Washing- to which the inauguration of the air- flac era in flight is due, more than to any other one cause. The document referred to is a true document; for it was found printed by natural forces on the rocks of the Solinghofen quarry in Germany. Here, ‘in a formation not less than seven million years old, one of the ancestors of the This is Nature’s first attempt at creating a flyer A Bird with Four Wings When Nature decided to evolve a bird out of a reptile she _ molded a four-winged flyer curiously like the first flying machine | By Maurice Krosby modern bird, a strange feathered reptile, had been imprisoned, caught unawares per- haps in one of the every-day upheavals of that formative age when mountain ranges, continents and oceans were still in the making. Its skeleton, its outlines and its feathers are here preserved, stamped in un- mistakabledistinctnessin stone, which is now hard but which must have been plastic as clay when the fluttering creature was seized in deadly embrace. More than twice as old as any of the prehistoric monsters reconstructed from their bones in our museums of natural history, the fossil im- print of the Tetrapteryx, as this creature has been named (mean- ing “‘four-winger’’), represents an indisputable and descriptive rec- ord of perhaps the earliest feath- ered flyer. The Tetrapteryx record was discovered fifty-five years ago, but science has only re- cently undertaken to interpret it mechani- cally. William C. Beebe, while curator of birds at the New York Zoological Park, demonstrated that several species of modern birds, and especially the white-winged dove, show very marked traces of just such wings on the legs, called pelvic wings, as the Tet- rapteryx record reveals. On the very young dove, at the time when its body is still bare but for the sprouting flight feathers of wings and tail, twelve flight feathers and six -coverts begin to grow from the outer and upper edge of the leg, extending in two rows from the knee almost to the base of the tail. While the growth of these tell-tale feathers is soon arrested ang is covered up 4 Popular Science Monthly in the surrounding plumage, so that the original, four-winged bird. The latter grown bird shows only traces, the fact came from a race whose fore and hind that the young of the species pass rapidly through the same evolution that is repre- sented’ in the succession of innumerable generations of their ancestry, almost clinches the conclusion that birds are descended from a type equipped with wings on all four limbs, as the Tetrapteryx, and that Nature has learned gradually to replace four small and imperfect wings, weakly mus- cled, by two larger and stronger wings under perfect control. Frederic A. Lucas, Director of the American Museum of Natural History, called attention last year in the American Museum Journal to the great force of the evidence which has thus been collected to prove how Nature learned to ac- complish flight, the in- terest centering in birds, on account of their con- siderable weight, rather than in bats and insects. The ancestor-bird, faithfully re- produced from the record, and the ancestor-airplane are presented in illustration herewith, side by side. The dimensions of the bird have been relatively exaggerated to fa- cilitate the comparison, and the re- semblance in structure is striking. Langley’s ‘‘aerodrome”’ repeatedly flew over the Potomac in 1895, sustaining its own weight in the air for more than one minute at a time by the action of its two pairs of planes or wings and two rotary propellers, of five tosix feetdiameter, driven from a diminutive steam engine developing one to one and one-half horsepower. The necessity for placing the power equipment and the _ propellers amidships called for an elongated body for the machine as a whole, so that the weight might be evenly supported by planes at the rear as. well as in front. This con- structive difficulty has been over- come in modern airplanes, but it was decisive for Langley’s machine,’ with- gliding machine. its small power, in the same degree and almost for the same reasons as for the a PW As the wings in- creased in power the rear wing decreased in size. Gradually the tail shortened and the feath- ers lengthened The fan-shaped tail of the bird of to-day is a kind of a rudder quer oad er atmosphere. limbs were spaced well apart, whose legs were relatively heavy and whose arm mus- cles were weak. Its struc- ture had to be modified by hereditary influences before it would balance at all in the air, hung from the arm sockets alone, as birds do. Mean- while Nature did practically as Langley did. She adopted the compromise solution of upholding the rear weight by large feathery extensions from the legs and tail, and it may be noticed that the fantastic feather tail of the Tet- rapteryx was built up around a. tail-like appendage and was not all feathers under muscular con- trol like that of the modern bird. Nature evidently found it impos- sible to change the bony structure in less than millions of years, working from the basis of a reptile with - only growth and heredity as the tools at command, but she could make feathers grow in the place of horny scales, which are made of almost the same material, by a comparatively briet evolution. To transform Langley’ ¥ aid! chine into the modern airplane was a task much simplified by the advent of the compact and powerful gasoline engine, small . enough to be moved forward in line with the support from planes arranged on the biplane or mono- plane principle and strong enough to pull the machine safely, in most cases, through dis- turbing. eddies . of. the This decided change in the machine took the place of all the transformations in bone dimen- sions, balance and muscle strength by which the Tetrap- teryx became a bird after start- ing out in the world with an ana- tomical construction very much like an animated parachute or But the mechanical flyer is still an infant compared with Nature's eon-old product. Naturally, it is radically different from the all the characters of one style are cast. “machine. By sliding it off and sliding on ‘characters, the typewriter is converted plate faces the front. At _ knock the writing paper tual impression of _ principle as in other This Typewriter Prints in Every Type and Language HE multiplex. typewriter, shown on the right, can type in all the languages and in hundreds of different styles of type. usual machine. Instead of having fifty different type blocks all mounted on sep-. arate steel bars, it uses one plate on which This plate is removably attached to the another plate having a different set of instantly. Two different plates, in fact, can be carried in the machine at one time. These plates are curved and can be adjusted into rae |b Four Exceptional Groups. Blanket Groups For $5.50 For $5.50 pair, white © pair, white blanket, with ~~ blanket with a cot) ; a ae tors FINELY pink :-and ders, sili X cee ,) blue bor- bindirig, \S So ders, silk ct gta pa nit: binding; eilin on -. mixed wool co a a “oo (ae ) and cotton warp, : ots Be tnohes, ; y filling on For $6.50 , A cotton same quality) Mes warp; 70 x 78 x 84 inches.” 82 inches. For $12 pair, art wool _ For $6.50 same quality, 76 x 84 ah inches. : & ee = bound, For $12 pair, ge wool laid blanket, silk bound, Third Gallery, New Building. Mo x 84 inches. Third Gallery, New Building. The advertising manager can send his copy to the printer looking just as he wants it to look in type a slot in the circular type-carrier after the carrier has been withdrawn from the machine. The type-carrier fits into the center of the machine. When a key is pressed, an automatic spring mechanism turns the carrier until the corre- sponding characteron the the same time, a hammer at the back is released to against the ribbon and the character. The ac- the character is thus made on the same ene eed typewriters. Popular Science Monthly 5 my A typewriter which prints any kind of type. Samples of its work appear on the left guists, to physicians and to all who have to use unusual charac- ters, this typewriter is invaluable to the advertising man. An ad- vertising manager of a large de- partment store, for instance, can send his advertisement to the newspapers all written in the cor- rect style and size of type. - This Railroad Crossing Cleans Itself and Eliminates Jolts HEREVER a road crosses railway tracks, this light weight steel cross- ing belongs. It will fit any standard-gage track, it can be put down or taken up by one workman in thirty minutes, or in case of repair work it can be adjusted to a skeleton track in ten minutes with sufficient security to allow teams, automo- biles and other heavy traffic to pass safely. Its surface is such that mud, snow, gravel, sleet or ice cannot geta purchase, yet its knobs prevent “ " Besides being of This crossing provides a level space between horses from slipping. _ especial value to lin- the tracks and a sloping surface to the road It eliMinates jolting. How Our Fighters Will Be Fed Nothing is left to guesswork. Menus are planned by chemists and physicians tee ate ae be Beans ew ye #3 reir 1) Bice Above: The daily Army ration of the garrison or permanent camp. Other articles in prescribed quantities of equal food value may be substituted if desired Potatoes It costs the Government only about twenty-eight cents a day per man to provide such wholesome- looking meals . as this on _ the left for the men of our Navy hotos © ; Press Illus. Serv. NCLE SAM has written generous | | menus for his fighting men on land and on sea and if the regulations which he has prescribed are followed his soldiers and sailors need never go hungry. He provides approximately twenty-eight cents a day to buy food for each one of his soldiers and a like allowance is made for his sailors. To the housekeeper who has to contend with war-time prices of food- stuffs, this sum seems entirely inadequate, but it must be remembered that Uncle Sam buys his supplies in ton lots and not by. the pound. There is no guesswork in either the army or the navy when it comes to deter- mining just how much food a man shall be given. All this has been figured out and the person charged with the responsibility of supplying the food merely follows certain tables. The fixed allowance or portion of food furnished a soldier or sailor each day is called a ration. It consists of specified components or substitutive articles. There may be an over-issue of any ration com- ponent, provided there is an under-issue or equal value of other components; but the total cost of a man’s rations at the end of a month must not exceed the average of the daily allowances for that period. . In garrison or permanent camp, a sol- dier’s allowance of food consists of the following components and quantities, or specified quantities of substitutes: Beef, 20 oz.; flour, 18 oz.; baking powder, .08 oz.; beans, 2.4 0z.; potatoes, 20 0z.; prunes, 1.28 oz.; coffee, 1.12 0z.; sugar, 3.2 0z.; evaporated milk, .5 oz.; vinegar, .16 gill; salt, .64 oz.; black pepper, .04 02z.; cin- namon, .O14 oz.; lard, .64 oz.; butter, .5 0z.; syrup, .32 gill; and flavoring extract, .014 oz. A number of substitutive articles are pro- vided for each of the ration components. For instance, instead of the 20 ounces of beef, a like quantity of mutton may be supplied or 12 ounces of bacon, 16 of canned meat, 14 of dried fish or other meat sub- stitutes. Instead of the bean component, 1.16 ounces of either rice or hominy may be supplied. . Prescribed quantities of dried apples or peaches or of jam and preserves may be substituted’ for the prunes. The reserve ration is less varied. A Photographic Trick—Try It on the Night of the Fourth HE young man in the accompanying illustration, pictured as looking so calmly and critically at us from behind one of the rings of Saturn or some other astronomical wonder, is really standing out in his own back yard, in Hornell, New York, and posing for his pho- tograph while whirling a sparkler, such as children delight in for the safe and sane Fourth of July cele- bration. A four by five camera was used with a poly- chrome plate. The photograph was taken by the light of the sparkler, and the dark spot over the right shoulder is the hand which held and whirled it. A Suitcase Laboratory for the Use of the Laundryman “THE Mellon Institute of Industrial I Research has been studying the laun- dry business scientifically. help the laundrymen guard against bad The result has been laundrv materials. The suitcase labor- atory which is used by laundrymen for testing the materi- als they use and the hardness of water Popular Science Monthly Posing for a photograph by the light of a whirling sparkler which he holds which valuable 7 the suitcase laboratory illustrated, with information is quickly obtained as to the purity of chemicals. This ‘‘pocket edi- tion” laboratory en- ables the laundryman to test all his materials ashe buysthem. Thus he is able to assure himself that everything used in his establish- ment is of a sort that will not damage or harm the goods en- trusted to him. In other words, he sub- mits all his purchases to a chemical analysis, without going to the expense of hiring a chemist to do the same thing for him. When closed, the lab- oratory resembles a suitcase. It becomes a laboratory by raising the handle side and lowering the side which forms the lid. The lowered side forms a table. It wants to A Hint to Motorists—Keep Your Radiator Clean O assure the efficient operation and long life of your automobile, it is essential that the radiator be kept clean. Every radiator has been designed for the purpose of dissipating some of the heat from the engine to prevent it from over- heating. The radiator can only accomplish this when the radiator cells are cleared of mud so that the comparatively cool air can circulate through it. Yet many are the cars which are allowed to clog up with mud and dirt until it al- most takes a hammer to knock it out. A good antidote is a powerful stream of water from a _ hose; or where this may not be convenient, a stiff brush or a broom will assist in solving the cleaning problem. Care in this respect will be repaid in good measure. The Flag Equipment of an American Battleship At right: The dragon flag of China and the white ele- phant of Siam Photos © Press Illus. Serv. At left: Centerpiece. of the flag of Salvador, difficult and expensive to make. At right: Centerpiece of the flag of Costa Rica, which requires | more than two weeks to make *ttPrairpaggys Below:Meas- uring and cutting the flags. This is laborious The complete flag equipment of an American battleship. : Each flag is carefully rolled and packed away in a waterproof bag to await future use About 250 flags are carried. Consists of 250 Flags of Various Kinds Costing $2,500 Hand sewers putting in centerpieces of foreign flags. In the background is the Mexican flag Below: Experienced women flag makers at work in the Navy Yard of New York City Photos ©) Press Illus. Serv. Above: How the stars are cut out. A machine does the work accurately and _ expeditiously Measuring and basting up flags on the floor. The method is laborious but it is the only one possible. The President’s flag is pictured in the bagkground 90 uayze} puUIy 2y} ore soimjoid a1doss00s03$ ajnt yessues e& sy ‘suesuI Joy3o Aue Aq a]qQeUTe}GQoUN UOTJeUTIOJUI YUM pes jersues 9y}3 Ajddns 03 ajqe st ay ‘Ar10z1I103 s,Auoua ue ydesSojoyd 0} aqe st eiowed e 4M poddinba JozeAe 9y} osnesag = “yJOM BurJazIOUUODI Ut ouedire ay} JO onjeA ay} poystqej}so sey Jem sty} ‘sBuTYy} JoyJO. Suoury ‘ouefdsre ue wos poydesBojoyd ‘eyruoTeg Jo Mata aMo-s,pnq YW “AIO “sn sse1q GO) on Greece 1eS on MN vo = wS ae irp A — tees 8 An New York Firemen Have Strenuous Training It looks easy, but would you care to try it? The only safe way to strike a life net is with feet and hands extended. This method has to be mastered by the probationary firemen Photos © Press Illus. Serv. Above: Climbing by means of a scaling ladder, and sliding down a rope, using a safety brake appli- ance. At left: The correct position to. assume when jumping into a life net Holding the net in the right way. Note the posi- tion of the hands. They are held neck high and the palms are turned toward the men to be in the best q position to resist the pull 11 Tests Which Scientists Use to Show Why We Can The eye is a kind of pho-: tographic camera. You don’t always want a bright light when you photograph, and neither does the eye when it sees. A camera has a dia- phragm which can be opened more or less to regulate the amount of light admitted; the eye has an iris which does the same automatically. But the eye can be fooled. In the picture the observer is look- ing through a lens at an object. When the object is moved farther away and the lens removed the iris opens to see better, and yet the intensity of the light has not changed and the widen- ing of the iris is unnecessary Photos by Jacques Boyer At left: An interesting test to prove to the human brain that the muscles can lift a greater load than seems possible. The load is increased very gradually The ‘“olfactometer” which de- termines the density of vapor at which the first perception of smell is possible. By its use we learn that there are many odors which we do not perceive 12 Not Always Believe Our Own Eyes and Ears Another trick played on the eye is shown in the illustra- tion at the left. A man looks through a lens at an object placed a short distance from it. The object is then moved farther away and the lens is removed. The brain realizes that the distance has been increased and here again the iris of the eye widens, even though the intensity of light was not altered Your sensitiveness to tempera- ture may be tested by placing your hands in two jars of water of different temperature. If the hands are crossed as in the picture above, it will be almost impossible to tell by the sense of feeling which hand is in the hot water and which in cold Acuteness of hearing is determined by varying the volume of sound let into the ear through an opening in a tube. For some people the full volume of sound may be audible through a tiny section of the opening while others get it only through the fully opened tube Photos by Jacaues Boyer _ 13 The Oldest Man-made Things in the World The oldest canvas painting in the world, executed about 3,500 years ago, found in Upper Egypt by Robert de Rustafjaell. The paint work has fortunately been preserved in all its freshness The oldest known sculp- ture represents a seated man clasping an oval- shaped vase. It is prob- ably 7,000 years old and bears witness to primi- tive man’s conception of beauty and manly grace . The finger imprint in the circle preserves to us the oldest evidence of man, estimated at 250,000 years Seen sO At left above is the earliest known painting of a Christian subject on canvas—the Saints Raphael, Michael and Gabriel. At right above are two baby shirts, the oldest known shirts 14 Improving on Man’s “Natural Finish” Tattooing is~ per- formed by punctur- ing the skin and in- troducing under it colored fluids to produce an indelible stain in a pattern Above: An elabo- rate example ofEng- lish tattooing—an eagle pursuing birds Japanese tattooing executed by Hori Chyo, a celebrated exponent of the art At right: Coat of Arms and motto tattooed on the arm of an English officer Goddess of the Night, tattooed by Sutherland Mac- Donald on the back of an Englishman. This seems. too fine a specimen to be covered up Picking the Best in Brain and Brawn Photos © Int. Film Serv. An officer explaining the significance of a battleship’s hoist flags and how they are raised into position Instructors teaching a class of young blue- jackets how to tie and splice ropes. On the board are various ex- amples of knots and splices, some. of which are extremely difficult to master A recruit undergo- ing the eye test. . First one eye is ex- amined and then the other. The sailor is operating a board containing letters of all sizes A detachment of bluejackets, members of an artillery division, going through a field drill on board a man-of-war. Sham battles are carried on in deadly earnest 16 and Training —Them for the Navy Photos © Int. Film Serv. Taking the chest measurement of a recruit. He is a fine specimen, with a chest expansion ef four inches. At right: The recruit picks out skeins of yarn that harmonize in color, to determine whether or not he is color blind A bluejacket squad prac- ticing overhead firing with the ordinary service rifle. Their targets are a fleet of imaginary enemy airplanes The wireless telegraph room and equipment of a modern battleship. The operator performs a service which is second in importance to none Making Motor-Car Bodies to Order There are styles in automobile bodies just as there are in mi- lady’s gowns. Here the pattern plotters are shown at work Above: Setting up the body after the various parts have been cut to order. The next opera- tion is to glue the parts securely together Wives of million- aires have car bodies built to order, with inte- rior linings that can be changed whenever desired to match a gown Putting the fin- ishing touches on a limousine body. None but an expert is trusted with this important task Photos Universal Film Co. Fitting the aluminum overcoat on the skele- ton body of white ash. The fit must be made absolutely perfect to with- stand the vibration A body, with its aluminum over- Special workmen attaching the coat, turned upside down for trimming and upholstery a part of the fitting operation to a modern high-priced car 18 Killing the Dry Frog in the Opera Singer’s. Throat Ph otos © Press Illus. Serv. Contrary to your first impression the figures in the first picture are not fortune- tellers but opera singers playing cards in an inhalation room. They are breathing the prepared air which is said to be beneficial to the throat. From right to left are Pasquale Amato and A. de Segurola. In oval: Taking the nasal douche. The singers are A. de Segurola and Pasquale Amato 19 . The European Trenches Are Not the Only Gas masks a new development? Hardly. They have been used for years in American industries. At the left a girl is shown putting caps on bottles of disinfectants Photos © Kadel and Herbert Foreign cotton has to be disinfected to kill the boll weevil. Here it is treated with hydrocyanic gas, pumped at a pressure of 1,000 pounds a square inch. A whiff of the gas is fatal Handling barrels of chloride of lime which gives off an irritating dust pow- der and chlorine gas, the destructive gas used in trench warfare. The men are well protected by their masks Photos © Kadel and Herbert " Places Where Gas Masks Are Necessary A gas mask worn by the photographer enables him to take a picture of the man who is shown at left below repairing _a leak in an ammonia tank. Dur- ing the time the photograph was taken choking fumes of ammonia were escap- ing in great volume from the tank, which is situated in a cold storage plant Repairing the ammonia tank, a task made safer through the use of the gas mask. The cylinder below the mask contains chemi- cals which absorb all of the poisonous fumes and allow only pure air to reach the lungs A chemist experimenting with a dangerous combination of chemicals which give off poi- sonous fumes. With the gas mask pro- tecting his nostrils, he is able to approach close enough to his work to watch it intently How the Stay-at-Homes Can Provide the Sinews America turns to ‘the soil in earnest. Even women are responding to the call for active service. Mrs. Ruth Litt, the wealthy suffragist, has turned over her 135-acre farm for cul- tivation, the work to be done entirely by women. The photograph below shows Mrs. Litt, Mrs. Grace Homer, Mrs. George Baxter, Jr., and Mrs. Charles Gould at work Photos © Int. Film Serv. Three hundred acres of land in East Potomac Park, Washington, were given over entirely to the Boy Scouts Brigades by the Government to be cultivated as a vegetable garden 22 of War for America and Our European Allies Photos © Int. Film Serv. Picture continued from opposite page. Citizens of Nyack,’ New York, leave their rifles at home temporarily and go forth to wage war against the soil with farmer’s imple- ments. .The men are shown preparing the ground for garden products A Chicago girl do- ing her farm bit to back up the na- tion’s fighters. With six other girls she was transferred from her employer’s office to his farm The Rockland County Patriotic Society on their way to charge a ; ten-acre plot and convert it into a vegetable garden. They believe that the spade is as valuable as the rifle 24 Popular Science Monthly The Poison Gases That Kill Men in Trench Warfare E do not know defi- nitely the composition of the gases used in trench fighting. From the appear- ance, odor and effects on the men it is believed that a mixture of chlorine and bromine is employed with the possible addition of sul- phur fumes or formaldehyde gas. Germany produces chlorine and bromine in large quantities. These gases at- tack the eyes, the lining of the mouth, throat and nose. One part of bromine or chlorine in one thousand parts of air produces almost instant death. The gases Getting ready for a ‘“‘hold-up”’ picture. Making “‘Night Scenes’’ for the Motion Pictures HE Limited is held up! Light from a switchman’s lamp or from the high- ‘ waymen’s bull’s-eye illuminates the harrow- ing scene. Or so it appears on the screen at the motion picture theater. Asa matter of fact the light is supplied by a semi- circle of flaming arcs such as are used in the ordinary studio for “‘close-up’”’ photographs. The only necessary feature which the studio cannot supply is ' the darkness. In order to get the realistic impres- sion which marks the success of a picture, a night scene such as the one described must be taken in the genuine blackness of night. The accompanying illustration shows the director of such a motion picture lining up his characters and adjusting the lights preliminary to taking the picture. The arcs are fed from the dynamo of the car. The light is very brilliant and is exceed- ingly hard on the eyes since it has to be flashed directly into the faces of the actors. For this reason such night scenes are not as popular with the performers as with the spectators. The blackness of night is genuine but the lights aré brought from the studio mer Joe, our office boy, posing with the largest straw hat in the world first cause a violent cough, followed by spitting of blood. The Largest Straw Hat in the World Is Yours If It Fits N the display window of a large hat manufacturing company in New York city the hat in the photograph below was recently placed on view, bearing the pla- card, ‘‘The Largest Hat in the World. If you can wear it it is yours.’’ Immediately one of the editorial family of the POPULAR SCIENCE MONTHLY be- came interested. Perhaps he needed a new straw hat. He was too modest, however, to take the company at its word and step right in and claim the hat by right of head dimensions. Not so the editor’s mascot— the office boy. He was not absolutely sure that the hat would fit but he was unwilling to let it pass without a trial. Boldly he went inside and tried it on, finding to his surprise that it covered not only his head but his shoulders and a goodly portion of all the rest of him. Thus convinced against his will, he nevertheless, proved his ability to wear the hat long enough to pose for a photograph in it, or under it, though it required both hands for the task. - bw Fast Is Your Typist? This Inge- nious Machine Will Time Her NVENTORS have tried for years to put i a counter on the typewriter to estimate the speed of the typist, but the efforts have always been confined to a count of the words written. A recently patented device, called a cyclometer, counts every stroke which the typist makes ‘on the keyboard. It is fastened to the escapement wheel of the typewriter. ‘This wheel does not move tien the carriage is ‘shoved backward and forward. One firm employing fifty typists found that ‘its work was below nor- mal by cyclometer count ‘and later that it had some very rapid typists and; ‘some very slow ones. _The rate of pay had always been based on the number of years of service, and many of the slow ones were: being paid for the work done by the rapid operators. “This of course was quickly adjusted. The Grave-Digger Beetle—Nature’s Sanitary Policeman HEN an animal dies in a garden or in the woods and decomposition be- gins, carrion bugs come from far and near. A dead bird, a mouse or a harmless snake wantonly killed by some wanderer pro- ‘vides a banquet for hundreds of insects. Among these the “grave-diggers’’ are found, embracing forty-three species, twelve of Popular Science Monthly The timing device records not only the number of words written but the number of strokes made 25 which are found in Europe, the rest in America. You can identify these beetles by the two jagged yellowish-red or reddish trans- verse bands upon their black wing-covers. Their scientific name (Necrophorus) means no more than “‘buriers of the dead.” . As undertakers, the insects have legs especially adapted for digging. A grave-digger beetle has a most extraordinary sense of smell. He can detect the peculiar odor of de- composition a long dis- tance away and flies to the dead thing as _straight as an arrow. His remarkably keen nose is situated in his club-like feelers. As a rule several grave- diggers are found near a dead body. They crawl under it and scratch. the supporting earth away, so that the body soon lies in a hollow. Gradually the body is lowered until it sinks below the surface. Then it is covered with earth. The female lays her eggs around the interred form, thus insur- ing for the newly hatched larvae a plentiful food supply. It is interesting to note that these grave- diggers can produce a curious creaking noise, by rubbing the fifth abdominal ring, which has two longitudinal projecting bars, on the under edge of both wing-covers. This noise is only made when the bug is attacked; it has therefore been con- sidered an expedient to frighten away its enemies. Nature further fortifies the beetle with a general musk- like odor and by a _particu- larly strong smelling juice which it exudes like a skunk if touched. This odor serves as a protection from human beings, especially, as it is peculiarly unpleasant and penetrating. If the beetle is handled it requires several washings to remove the odor from the fingers. The grave-diggers are among the most useful of beetles. They have been so that it sinks into its grave. The beetles dig the earth away from under the dead body Then they cover it over designated Nature’s sanitary police.—Dr. E. BADE. ’ 26 How Scientists Capture Mosquitoes Alive for Experiment. and Study CCASIONALLY it Popular Science Monthly ’ When making a catch, the trap end of the tube is placed over the resting mosquito, which in attempting to escape selects the only way out, is necessary to do something else with a mosquito besides swat- ting it out of existence. In order to study the -best methods of annihi- lating it, scientists, health officials and en- tomologists find it neces- sary to classify the insect, dissect it and experiment with it. For these purposes it is nec- essary to collect the mos- quitoes without crushing them. Acollecting tube of any ‘ size may be used, but the one most approved is a glass or celluloid tube about five inches long and one inch in toward the light. This leads through the glass cone into the large col- lecting tube. The aver-. age time required for a catch is about three seconds. When the col- lection is made for lab- oratory use, not more than ten specimens should be taken in the tube at one time, lest the captives injure one another. A Japanese Inyents a Curling Iron ANJI TANAKA, a Japanese residing in Seattle, Washington, has invented a curling diameter. When in use one end of this tube is closed with a cork stopper and the other with a specially designed trap, the invention of Dr. T. H. D. Griffiths, of the Public Health Service, of New Orleans, La. The trap consists of a cork stopper to fit the tube. Into this a one-half inch central opening is bored to accom- modate a small somewhat taper- ing glass tube, the outer end of which is one-half inch in diam- eter, diminishing to three- eighths inch in diameter at the opposite, or inner end. Above is shown a collector using the mosquito trap to catch live specimens. At left is the tube, natural size iron, which is designed to make the hair-curling operation not only easier but more expeditiously performed. With it the hair may be curled and the iron taken out without the usual un- wrapping process. This is supposed to leave the curl in better form. By pressing a kind of button the curl- ing is done almost automatically. By another pressure the parts are unlocked so that they can be slipped out separately. Another advantage which Mr. Tanaka claims for his curling iron is that only one hand is required for the operation. This curling iron is in two parts so that it can be slipped. out. of: _ the curl in sep- arate sections Sliding nut to rotate worm gear " Attacking Mail-Car Robbers with Deadly Fumes T would be a sad gang of robbers who tried to break to the railway car invented by George W. Meyers, of the ‘United States Army. They would be greeted with clouds of poisonous gas fumes. _ Meyers’ robber- proof car works with extreme sim- aeeity. Two tanks, -in which fumes of cyanide of potas- sium are stored under pressure, are fitted inside of the car at~« each end. _ Theseareconnected with a perforated pipe which extends all around the door of the car, just in back of the outer framework. Should the train _be held up, the locomotive engineer would _ telephone the guards within the car, who would immediately open the valves of the tank. The fumes would stream out through the pipe perforations and into the robbers’ - faces. The door being gas-tight, the deadly gas could not penetrate into the car. j The overhead trolley system and the fastener keep the cow’s tail from annoying the milker ee The deadly fumes are turned on from their tanks through the perforated pipe ‘around the door Popular Science Monthly Q7 Making the Cow’s Tail Behave with a Trolley Restrainer OSUA AERNI and Joseph O. Venden, of Guler, Washington, have come to the rescue of the legion of tail- flogged milkers,with a device which makes the cow’s tail behave. Briefly, the de- vice consists of a clamp, which hoids the’ tail and an overhead trolley system which per- mits the holder to be moved from one cow to another. As the drawing shows, a rod is attached to the wire track in such a way that it can be readily moved and held in a rigid vertical position at the same time. - At its lower end it is joined to the tail fastener by a flexible cord. The inventors do not take the trouble to de- scribe their fastener, but it is evidently designed so that a ined spring. grasps the tail. Guinea Pigs Were Once Raised Like Chickens for Food HE cavy (guinea pig) is typically a pet animal, and has no other excuse for existence than the pleasure he gives those who appreciate his good qualities. . . . But it is to the undeniable edibility of the cavy that we owe the existence of the cheerful little squeaker of today. “‘The Incas of Peru long ago domesticated the wild ancestor of the modern animals —a small, tailless, unicolored member of the genus Cavix, the exact identity of which is a matter of some doubt. These creatures were allowed to run freely about the homes of their owners, whose object in breeding them undoubtedly was for their food value. “The time which must undoubtedly have elapsed since this domestication was first begun is evident from the entirely changed color of the present-day cavy.” (Pets, by Lee S. Crandall. Henry Holt & Co., New York.) ‘ “Silent Music”— A Hospital Recreation — A wireless system conveys the melodies to those who want to hear without disturbing those who don’t Suffrage reports by wireless. The contri- vance on the left is the receiving set with a few feet of ‘‘aerial’’ _ Below: The telephone sending station. By throwing a switch a voice transmitter is cut into the system to allow the operator to announce the record titles CHICAGO concern has come forward with a ‘“‘silent music” contrivance that is designed to furnish recreation to inmates of hospitals. With this system installed in a hospital, a continuous and noiseless program of music can be fur- nished. Each patient may decide for him- self or herself whether or not to listen, and if the decision is against such recrea- tion, the patient is not disturbed in any manner. Briefly stated, the mechanism consists of a phonograph attached to a telephone transmitter, which in turn is hooked up to an electrical wiring system that reaches each private room and each bed in the wards. At each wall outlet a watch-case telephone receiver is wired in. The patient desiring to hear the musical program simply lifts this receiver to his ear. The sending station equipment is located at the office or in any convenient room, and consists, as stated, of an ordinary phonograph, electrically driven, holding the turntable, which carries any disk record. Attached to this machine is a special music transmitter, consisting of a combination of a telephone transmitter with a vibrating diaphragm and needle. The needle, following the groove of the record, energizes the diaphragm of the transmitter, which in turn energizes the telephone attached thereto. Beside the transmitting apparatus is a control box, containing electrical resist- 28 ances, which energize the transmitting apparatus properly, and binding posts for all connections. By throwing a switch, a voice transmitter is cut into the system. This enables the operator to announce the names of the records about to be played, to give baseball scores, recitations, war news, and whatever other items may be of interest to his tele- phone clientele. Except when this voice transmitter is being used, there is no noise of any descrip- tion connected with the sending apparatus beyond a light scratching of the needle, for no tone arm or horn is used. When installing this system in hospitals in the course of erection, the wiring is made to connect the sending station equip- ment with outlet jacks at the bedsides. These outlets are all connected in multiple on a single pair of wires, carried along with the regular telephone or signal system. icko y, Dickory, Dock, the Mouse | Ran up the—Clock ERE are the creepy spiders, the - mechanical beetles, and the spring- »perated bugs which used to be the delight f the office boys and the terror of the fenographers? And surely the mouse has ds ae of its effectiveness as a scream- the action of a concealed magnet, so that the mouse appears to run up or down the wand in a mysterious way. . The wand is 1 square tube of light wood covered with The celluloid mouse has a “small piece of iron on the sottom which is attracted by “the magnet. When the wand ‘is turned up a small lead weight on an endless cord falls and draws along the magnet which, ‘in turn, takes the mouse with t. When the rod is tipped ‘mouse climbs up real- * WITH SILK overng of the space 4 is broken away to show the: interior mechanism, i —_—__ "These Wobotiying Ginabes Are Worn Like Spectacles “HE field of usefulness of the 4 binocular magnifier, shown in ‘the illustration on the right, in- ‘cludes the scientific laboratory, the “medical office or hospital, and the workrooms of botan- ists, metal workers, watch- : akers, etc. An elastic headband fastens it on so et both hands are free. The eye-pieces of vul- ite are fitted with cay in such a way runs up the all divergent angles. __ Asmallincandescentlamp | fitted with a reflector and condensing lens may be fast- ned over the top, current ing supplied from a bat- carried in the pocket. Popular Science M onthly WOODEN TUBE COVERED The celluloid mouse magnetic attraction Both eyes are used with this glass, so that the object exam- ined is seen in natural perspective 29 Why You Can’t Compare Ships According to Tonnage HE different uses of tonnage terms when speaking of ships are causes of confusion to the lay mind. For ex- ample, steamship companies in order to impress upon the traveling public the size, and conse- quent relative safety of their craft, will advertise the sail- ing of a certain steamer of twenty-thousand tons, mean- ing, of course, gross tons. The company’s agent, in en- tering her at the custom house, will take great precaution to certify that she is of only 7,340 tons, when paying tonnage taxes. He then is referring to her net tonnage, and in fact that stand- ard is used only when paying dues or taxes. Displacement tonnage is al- most exclusively applied to war- ships as they do not carry cargoes. Strange to say, the tonnage of a battleship varies almost hourly, as coal or other _ weighty objects are used or taken on board. The tonnage of war- ships is, however, fixed; they are referred to in terms of the fixed tonnage. A statement that a ten-thousand ton battleship sank a ten-thousand ton mer- chant ship does not mean that the ships were of equal size. The merchant ship would be much the larger owing to the different meanings of the term ‘‘ton,’’ as applied to the two typesof vessels. It isabsolutely impossible to give rules for the relations of these terms, as the conditions vary too greatly. Generally speaking, the gross ton- nage of a ship is from fifty to one hundred per cent greater than the net tonnage. Tons dis- placement are always in excess of tons gross; dead- weight tonnage is on an average from thirty to fifty per cent greater than gross tonnage.—Capt. C. A. McALLIsTER, Engineer-in- Chief, U.S. Coast Guard. : | j rod by Differentials for Motor Vehicles Comparisons which illustrate the merits of various types By Marius C. Krarup HE Bailey is the name: of a new differential gear for motor vehicles. It transmits power to both driving- wheels when these can rotate at the same speed, but only to one wheel when the other runs faster. The power is divided at the rate at which the wheels can utilize it for trac- tion if the wheels have the same speed but one is inclined to slip. Traction from one of the wheels is thus sacrificed on all curves, wheth- er the going is good or not, in order to con- centrate power and traction on one of the wheels when traction from the other is lost for lack of fric- tion with. the road surface from slippery mud or snow. The casing is rotated by a bevel gear or worm drive, as usual. To the casing are secured two heavy pawls, of which one holds the left and the other the right wheelshaft by engaging notched disks fixed upon the ends of the shafts. The pawls are pressed against ball-pivots by coil springs. Their seats shaped so as to make the engagement hold in either direction of movement, for backward as well as forward driving; but if one of the disks is forced around by the road contact of its wheel faster than the casing and the pawl are rotated by the power, this movement is permitted by means of a cam plate that lifts the pawl out of its seat. This action seems to be as follows: The pair of cam plates is mounted on a sleeve as a rigid unit that turns around with: the casing, and opposite to each pawl one of the plates has a semi- circular recess that limits sideways turning of the pawl on its ball pivot, while the other plate here has a straight-line contour passing obliquely under the active end of the pawl but coming to a point directly LT Mes ame - AXLE_SHAFT RING GEAR LEFT FLANGE’ 3 Ty a es BALL THRUST BEARING a ; WSJ A differential which concentrates power on one wheel when the other has lost traction on a bad road in the disks are- 30 before it This gives the lifting action. When both pawls drive, they stand at right angles transversely, balanced one against the other, but when one of the disks, actuated from the road, begins to push its pawl, the latter begins to turn a little on its pivot, allowing the disk the same small movement,and thereby the relatively im- movable cam plate gets a higher point of support under the pawl, rais- ing it and per- mitting the disk further unhindered rotation. A compari- son with other differentials illustrates the merits of each. In the ordinary balance gear differential of the type still used in a majority of motor vehicles the four small bevel pinions revolve on the plan of freely balancing the pres- sures on all teeth engaged. The engine power turns the casing which carries with it the two pivot pins on which two of the pinions are mounted. The two wheel- shaft pinions, each in mesh with both of the power-transmitting pinions, can con- form with the turning of the casing by revolving, taking the wheelshafts with them. If one wheelshaft resists as much as the other, one side of the actuating pinions is resisted as much as the other, and these pinions remain balanced and un- moved in relation to their pins. The teeth engaged become mere lugs gripping the wheelshaft pinions and forcing them to follow, by revolving. But, the moment one wheelshaft resists more than the other, from any cause whatsoever, the pressure on the teeth on one side of the actuating pinions becomes greater than that on the other side. These pinions are no longer DRIVE SHAFT DRIVE PINION SPRING PAWL RIGHT PICK-UP PLATE balanced. They begin to revolve on their pins, toward the low-pressure side. ‘ The high-pressure side of them no longer carries _ its wheelshaft pinion around unyieldingly. It lags till pressures are equalized, the _ wheelshaft with the higher resistance turn- _ ing more slowly and the other wheelshaft more rapidly in the same proportion. The _ total of power utilized remains unchanged, except that a portion of it is spent in over- ~ coming the friction of the revolving pinions. As friction adds tooth _ pressure on both sides, it -may be purposely increased Pin Pin bs _ Links and eccentrics ; Z 2 An eccentric can drive Links and 2° a link in and out but eccentrics - cannot be rotated by turning the link around to modify the action of the differential. _ For example, if the power delivered to the _ casing has a numerical value of 8 and the resistance of each shaft against rotation at a certain velocity is 4, no friction in the differential arises. But when road contact interferes and one of the shafts produces in- creased resistance at this velocity but only _ 4 at a velocity 3314 per cent higher, while _the other shaft produces 4 at a velocity 3314 per cent lower, _ such as may be the case wher ' a vehicle is made to turn on afairly sharpcurve, oneshaft _ is turned twice as fast as the _ other and a certain friction is produced. In the ordinary differential this friction is negligible; but suppose it is _ made to have a value of 2, then there is only a _ power of 6 available, and there is less than 4 for each . wheelshaft. The | vehicle speed is reduced or more © power must be i ice-box. Popular Science Monthly It is built strong enough to resist the stresses that arise in its operation The refrigerator-basket is the picnic party’s In it all perishable food is preserved 31 ‘turned on. Suppose, further, that one wheelshaft resists very little and does not © equalize tooth pressures until it is revolved eight times as fast as the other. Then the differential works four times as much as before and the value of the friction rises rapidly, perhaps from 2 to 8. The power is consumed. By arranging the friction on a less drastic scale, however, one can have a shaft which offers a rather small resistance under small differential action, yet equals the resistance of the other shaft as soon as its rotary velocity becomes only two or three times as high, after which no greater difference in shaft speed can be pro- duced. The power is then divided somewhat on this plan: 2 for the slow shaft, 1 for the small friction identified with its side of the dif- ferential action, 4 for the friction of the rapid shaft and 1 for driving it. If the wheel of the rapid shaft has no trac- tion, there is still a net power of 2 for driving. A Refrigerator Basket for the Picnic Outing LL the luxuries of home are now at the disposal of the vacationist starting off for a picnic at the beach or in the woods. The increasing vogue of automo- bile touring trips has also created a demand for portable creature comforts. A refriger- ator basket is a refrigerator in minia- ture, which keeps the butter hard, the meat fresh and the milk sweet. It consists of a rust-proof metal food container with a smaller ice compartment partitioned off at one end. Around this shell is a layer of insulating material to keep the cold air in and the warm _air out. Externally the carrier is a reed basket with convenient handles and straps to bind the lidsdown. Separate lids are provided for the two compartments. The Strength of Human Wings One hundred and twenty-two peaels can stand. on the wings of a big» biplane years of. the flying machine’s develop- if the men who lost their lives in the early _ment could come back to life and gaze upon: the picture which accompanies this. article, they would first gasp in astonish- ment: and then they would approve en- thusiastically: the construction which made it possible for: sixty: people to crowd upon one-half. of-a huge biplane’s wings without breaking. them: | For, Jet it never be for- gotten; that some of the early martyrs who dropped - to a’ terrible» death from great heights; went to their doom because the builders:of=their machines had no concep- tion ofthe structural ’strength required to . buffet: turbulent winds at high speed. _ Study. the picture well. Note that the wing, section: of a‘biplane here depicted is supported from a. Heavy wooden frame and not:-from.the’ floor... The wing section ‘is held} only. on: one side and extends freely from that-side into the air. Judging from their- size, ‘the wings are, those of any enormous flying yacht. Although the sup- porting surfaces of this yacht could evi- dently sustain the weight of some one hundred and twenty-six passengers, they have not, of course, that amount of lifting power. The crew of the vessel probably amounts to four. :Hence, the weight for one hundred and. twenty-two people is available for. the boat body, rudders, engines, propellers and supplies, something like over eight and one-half tons. More- over, the human freight here pictured clearly does notoverstrain the wings. The picture is an object lesson in reserve strength. The stoutest. storm-sails of an old-fashioned sailing ship were never sub- jected to such strains as those which must be endured by that fabric of linen, wires, and lattice-work of which the wings of a modern flying-machine are composed. A sail needs strength to resist mere tearing alone. A flying-machine’s wings must in addition be so rigid that they will keep its shape in the worst hurricane. Only the pilot of an airplane knows how his wings are strained when he drops at a steep angle from a height of five thousand feet in a swift downward glide for home. It must bend no more than if it were made of cast iron. To this stiffness". the. modern airplane owes > its superior stability. -Testing the wings of the great biplane by crowding upon it a maximum human load 32 - carline by pushing an Popular Science Monthly 33 F ‘Lost in New York? Consult an Electri- fied Street Directory HE man from Oshkosh or Paducah can easily find his way around New York city if he happens to stop at one of the thirteen hotels there which have in- stalled the electric directory. He can“find the location of —— any building, street, or electric button on the keyboard, for the location he is seeking will be il- luminated by a little six-volt incandes- cent lamp. The directory board is sixteen square feet in area and the map is di- vided into fifty-six sections for the city of greater New York. connected with the phonograph. The receiv- ing station may be located some distance from the actors and camera, so that as the people move about the stage their distances from the radio receiver will re- main relatively unchanged and their words will always be heard at about the same strength. — sree GREATER NEW YORK » RTT An oscillating: vac- uum tube will supply the necessary high fre- quency current, and the batteries used to run it may be made of very small size. A ground con- nection is secured through contacts placed on the soles of the actor’s shoes and arranged to touch a metal plate on the stage; the diminutive aerial re- quired may be con- The current for the board is furnished by storage batteries. Taking Records of Sounds by Wireless for Talking Motion Pictures HE problem of making talking motion pictures has been attacked by many inventors, but no more ingenious sugges- tion than that of Mr. William B. Vansize has been brought. out. According to Mr. Vansize’s plan, each actor is equipped with a tiny wireless telephone transmitter, and his speech is sent through the ether by “radio” to a receiving station which is desired location alafaalliteafetthk—-- a When the right button is pushed the flashes structed of a few thin wires projecting upward a foot. or two above the actor’s head, or may merely be a sheet of thin metal foil fastened across his shoulders under his coat. The micro- phone transmitter which his voice operates need not be visible, for it has long been known that the vibrations of one’s chest are amply strong enough to operate a tele- phone transmitter held over the lungs. The wireless waves sent out by each actor’s radio telephone transmitter pass over the space separating the stage from the receiving station, which may be several thousand feet away, and there affect a very sensitive wireless detector. This instrument converts the speech waves into telephone currents, which are carried back to the recording phono- graph by a wire telephone line. . The sound-recording in- strument may be either a magnetically controlled wax cylinder phonograph or a ““telegraphone,’’ which latter uses a thin steel wire instead of a soft cylinder or disk, and into view Nig = makes its sound records mag- netically. Whatever type of recorder is used, it is mechani- The wiring diagram of the apparatus which is worn by the actor. An oscillating vacuum tube supplies high-frequency current cally connected with the mov- ing picturé camera. The Newest Automobile Conveniences -° Truss shaped ‘Supporting plate \ Break in Spring A new shock absorber which A plate or truss which provides takes up shocks before they reach the car springs and the body of the car a temporary re- - pair for a broken spring. It sup- ports the break longitudinally The man who is pressed for time has his car fitted up with a disappearing desk and typewriter A spring cushion tire to eliminate blowouts. The inner tube is a series of heart- shaped springs Core on which Cushion travels Made of Swedish |steel springs A convenient luggage carrier strapped to the rear of the front seat. It is about three feet long Locking Device Roller Bearing An automatic lift which enables the autoist to “get out and get under” without lying on his back. The car is run on to the lift under its own power. The lift is both demountable and portable 34 Two facie one Sting up istic the other went ahead, moved this house seven miles across country in afew hours. By old methods of house moving the job would have taken weeks An attachment by which a Ford is converted into a six to twelve horse - power stationary engine A small transformer, wired as shown, gives steady-burning electric lights on a Ford car A spark-plug cleaner which makes it un- necessary to take the plug apart to scrape off the carbon Lifting a 1000-pound wheel to the hub of a motor-truck with a strong portable mm A a Pressed down with the foot a slot - block locks the gearshift crane lever, thus® foiling thieves g Measuring Motor-Truck Loads Automatically A dial registers the readings from all four wheels as the load is distributed would be entirely eliminated if all such once ately of motor trucks trucks were fitted with the novel load- - measuring device shown in the accompany- ing illustrations. The apparatus makes use of the relative motion between the axles and springs of a vehicle as loads are applied. The varying deflection of springs for loads of dif- ferent weights is allowed for by calibrating the dial scale on which the loads are read. The device differs from most others of its kind in that the weight carried on each wheel is recorded on the dial as the load is distributed, and not only that on the rear wheels. The proportions of weight over the truck body must be the same as when the device was calibrated or else the read- ing will not be a true one. This makes it possible for the load to be properly dis- tributed over each wheel. The readings are obtained through the use of four verti- cal racks, each carried rigidly on a strap round each axle near the ends, the rack re- volving a spur gear mounted on the frame and driving a longitudinal shaft inside the frame channel through a Detail. of the rack which revolves the spur-gear mounted on the frame LONGITUDINAL DIAL DRIVE SHAFT BEVEL. GEAR AXLE STRAP VERTICAL RACK VERTICAL ' AXLE STRAP RACK mer, 8S tt | ue a — pe ¢ ~ BEVEL GEAR ea Overloading is one of the greatest dangers which the motor-truck owner fears. It is a question of correct weight distribution bevel-gear unit. The revolution of the shaft is transmitted to the reading dial placed on the dashboard of the truck in sight of the driver by means of a flexible shaft. As the load is put on the truck, that portion supported by each wheel forces the spring carrying that wheel down and causes the spur gear on the frame to revolve about the rack nearest that spring, simultaneously turning the ‘corresponding longitudinal shaft and the flexible shaft registering the relative motion between the spring and the axle on the reading dial. The weights carried on the other three wheels are registered in a similar manner. The registering dial is a clever piece of mechanism which consists of a cylindri- cal casing with a central fixed stud carrying loosely four gears of like diameter VERTICAL RACK BEVEL GEAR | x AXLE STRAP Jrensue SHAFT ® LONGITUDINAL DIAL DRIVE SHAFT : ‘O i] ‘he : DIAL - FLEXIBLE SHAFT BEVEL GEAR AXLE STRAP VERTICAL RACK The readings are obtained through four vertical racks, each carried rigidly on a strap round each axle near the ends and éach revolving a spur gear driving a shaft through a bevel-gear unit 36 spacedalongitslengthon ,, telescoping journals. G Popular Science Monthly 37 fluid well with a screw-in Each journal carries a hub to which are attached curved radial arms or spiders of similar contour , but of varying sizes. At their outer ends each set of spiders carries a con- centric ring in the same plane and these together {L = piston by means of which the compression of the fluid may be varied for calibration purposes. Still another method employs a_ steel tape attached to the top of the axle near each wheel and carried over a roller al on the vehicle frame and Hollow cylindrical constitute the face of the registering dial. These rings are moved to the left or right of an assumed zero load line drawn from the center stud to the circumference of the casing by means of spur gears on the end of each’ flexible shaft which extends through the back of the casing. The spur gears are within the : casing and are arranged as Register for planets around the central 'eft front stud and in mesh with the corresponding gears carried on it. This gearing is so arranged that the movement of the rings clockwise in reference to the zero line | refers to the loads carried on the two right wheels of the truck, looking toward the front, and the counter clockwise turning of the alternate rings refers to the loads on the left wheels. Calibrations on each ring enable the load on the corresponding wheel to be read directly in multiples of 100 left rear Above: H _ pounds or fractions of tons as desired. With the dial mechanism remaining the same, the movement of the registering rings may be accom- plished in two other ways in one of which a piston attached to the vehicle frame works in a cylinder substituted in place of the vertical rack on the axle to force a fluid to a second cylin- der having a piston whose rod carries a rack turning the end of the flexible shaft leading to the measur- ing dial. The latter cylinder may be pro- vided with a small under the desk. Register for The load carried on each wheel is given on the dial. ow the revolution of the shaft is transmitted A sliding letter rack utilizes the waste space This is locked into place thence toa take-up wheel with a spring coiled around its axle and its outer end made fast to the frame. Not Even the Space Under This Desk Is Wasted ENRY J. WILLIAMS, of Brookline, Massa- chusetts, has patented a filing rack which utilizes the Register for space under the desk beyond HG tfront the reach of the knees. The i ala rack slides forward when be bedi the letters are being filed; then a push by the hand sends it back out of the way. The desk is thus as comfort- able as before, while expen- sive floor space otherwise wasted is made use of. The rack consists of a platform which is supported upon waxed strips for guides. The platform can always be reached by the foot and drawn forward when wanted. A light chain on the platform is attached to the rear of the desk so that the rack can- not be pushed too far forward and the letter files be spilled. Two bars are provided in front, which when brought together and locked, prevent the files from being removed. The most popular office desk of the pres- ent day is the flat-top style. Under it there is an unusual amount of space which could easily be utilized to advantage by the in- stallation of such a cabinet or rack as the one described. The material or books are kept free from duSt. Our Big Guns and How They Are Made It is the most powerful thing on earth, is a great gun, but its actual firing life is not as long as the life of a butterfly Illustrations by Kadel and Herbert T is not easy to understand what the power of a gun really is—its penetrat- ing and destructive power. What we call a 15-inch gun—which means one whose muzzle or hollow part is 15 inches in diam- eter—will hurl a shell right through a plate or wall of the hardest steel 12 inches thick seven miles from the muzzle. The power of the very largest land guns ever made— the German howitzers or 16.5-inch guns— is such that one of their missiles cracks open a steel and concrete fort as if it were a nut. “Built-up” and Wire-wound Guns and What They Are There are two classes of guns—naval guns and army or land guns. Because they ~ can be manipulated more easily than those of a ship, land guns are the heavier. From eight to ten miles is the greatest distance that a gunner can cover success- fully at sea. The largest naval gun is the 15-inch English gun on the famous super- dreadnought, and the largest land gun is the German howitzer. Of the two the naval gun fires a shell weighing over half a ton, while the other fires a projectile a ton in weight. But the new giant 16-inch guns of the United States defending the Panama Canal and New York at Sandy Hook shoot projectiles weighing 2,370 pounds, which is over a ton. These im- mense steel guns can sink a ship before it has really come into sight on the horizon, the location of the battleship having been determined by airplane or tower. How are these huge pieces made? The first step is the making of the pig iron from iron ore in large furnaces like towers, — called blast furnaces. Then the pig iron is melted with other steel in large steel furnaces called ‘‘open hearth,” until it is freed of its impurities and converted into steel.- The melted steel, thin as. water, is run from these furnaces into big iron molds where it is allowed to cool into large solid cylindrical or corrugated blocks. After cooling these are reheated and reduced in size by pounding them with big steam ham- mers and squéezing them in rolls until at last the steel is pressed into a long barrel- like mass, the embryo of a real gun. This long skeleton of the inside of a gun must be bored out from one end to the other on immense lathes, some over The man is leaning against his completed work—an immense steel gun—the most powerful product of his skill. The various hoops that go to make up such a weapon are easily picked out—large steel bands which are put on one after another as described in the article. It is impossible to determine whether this is a built-up or wire-wound gun. The breech is clearly shown 38 Stages in the Making of a Big Gun At the top, a glimpse of one of the big gun-heat- . ing furnaces. The huge steel’ ingots or blocks are heated before they are worked or forged to a smaller size, just as a ‘blacksmith forges down a tool. Big cranes handle these heavy steel: pieces by means of some of the mechanism shown and insert them into a furnace or draw them out with the utmost ease. These heating or soaking fur- naces, as they are called, are fired by gas, oil or -oal. Steel, to be worked or kneaded like bread, must be at a white heat *~ . tee 3 ” 40 Popular Science Monthly go feet long. Heavy as the mass is, a huge lathe turns it around as easily as a body turns a spool. After the inside has been rifled or scored to form an inside surface that gives the shell a twist before ‘it leaves the muzzle and causes it to fly straight, the lower or muzzle end of the gun is made larger. This may be accomplished in one of two ways. Either additional shorter steel tubes are placed over the main inner tube, or the main tube is wound with wire and finished with an outer tube. The wire-wound guns are usually the heavier and are used on board ship. Why the Wire-Wound Gun Is So Strong The gun bound with wire is really stronger than the one built of bands or rings of steel, one on another; for the wire reinforces the gun tube so that it will safely with- stand the tremendous strain which is constantly put on it when it is fired—said to be as much as seven- teen tons pressure on each square inch. This means a pressure on every little space inside the gun as big as a domino of over 38,000 pounds. No wonder that a gun Bt ORGK ‘« TUGEOF 16° The upper portion of a blast furnace in which pig iron is made—the first step in making steel. These men are dumping iron ore, coke and limestone into the large hopper. The materials are allowed to. fall at intervals into the inside of the furnace where the intense blasts of hot air cause them to melt, mix and fuse together until they are tapped out at the bottom eit This is a steel ingot. It is the large block of steel resulting from pouring the hot liquid steel into a large mold and allowing it to cool. After it is cold the ingot is taken, in the manner here shown, to the large forge shop for conversion into a big gun. This block weighs something over 111 tons ¢ the Furnaces with Iron Ore in ‘ON el © = 0 JTPSPE DOVUIN 4SE[A 94} Ul UOIT OFUT 9JO 94} BUTZI9AUOD Ut JOJeF [edrouLId dy} st YyoTYM oInzeIJ9duID} YBZIY & 03 AsETq 24} Je9dY S9AO}S OsOy, ‘“aoeUIN] & yons Suruuns Joy Aressaoau SABMIE S2A0JS 3914} 24} JO OM} oe ‘adBUINy 3seIq 94} Se ysty se Ajieou ‘syoelqo axI]-2UIOp OM} a4, “dIQISIA SI 49eRS Jo sovuIny yes Jo Weq “Surpusosep sjeny pue Jo 94} pue BZurpusose sase3 94} ‘sAouumyo JUBIS SAI] S1ouI ore Ady} JOR} UT = *sHOw}S STqQuiesoz pue ysiy ore soovuIny asoyJ, “9JO UOIT Y}IM JI Buy Jo Sursreyo ore usur 0M} sures 24} S19YM soOBUINY YseIq B Jo do} ay} Jo MaIA JoyjOUy eee +4 t eas wl H 41 A Great Modern Gun-Shop Where the Giant The immense machine shop of one of the largest American steel companies making big naval and army guns. The sides of this vast building are lined with machine after machine and lathe after lathe for cutting off and reducing to accurate size sections of steel for various purposes. Extremely accurate and skilled work is done here by experienced mechanics. 42 Tubes of Guns Are Machined by Lathes | ee es GEE "CS Sere agg | wey. ; i if fc fe. § tet i | tt i } In the near foreground of the , picture above can be seen the barrel of a big gun that is g bored or cut out hollow on its inside by a big lathe. Some of these lathes are very long. se rs section of the picture on page 42 one of the guns in a crude shape is beingscarried by a ig electric traveling crane to a large lathe where the first paring or cutting % to be done 43 4A Popular Science Monthly The red hot steel about to be plunged into the oil tank for what is known as its ‘‘heat treatment.” The tank extends down into the ground. The plunging of the hot steel into the oil suddenly cools it and hardens it and refines its grain or texture. After this it must be heated up again to temper it must be strong and that its life is short! In the case of a ‘‘built-up’”’ gun, as it is called when made of hoops or bands of steel, the outer tubes or rings are shrunk or sweated on—that is, they are heated so that they expand or swell a little, as all steel does when heated, and then while hot they are fitted over the inner part and allowed to cool and shrink, or contract. In so doing they fit very tightly on to the - main tube. In making a wire-wound gun, the wire is wound or coiled around and around until more than one hundred miles of it has been wrapped around the big cannon. A 12-inch gun requires 117 miles of wire weighing about thirteen and one- half tons. Although the strength of the wire is such that it gives great resisting force to pressures exerted sideways, it does not bestow strength lengthwise. Therefore an extra thickness of metal must be put on the muzzle of the gun where the vibra- tion caused by the shell leaving the gun is the greatest. The breech or back end of a gun is a very important part. Here the shell is inserted in a _ specially built chamber. After the shell is in place, the breech is closed by the shutting of a very complicated and strong door. It is fastened or fitted in- the gun by extremely strong screws so that the charge will not burst the gun open at the back when it is fired. Sometimes a shell explodes in the barrel of the gun. In a wire-wound gun the wire tends to prevent a grave disaster; it hinders the steel tubes from bursting into many pieces and flying in every direction. The solid gun is wholly built of tubes, while in the wire-wound gun there may be one or two tubes over which the wire is wound with the jacket tubes shrunk over the wire. A bush for the breech-ring is screwed into the rear end, which is also reinforced by a bréech-ring outside. Heat Treatment and What It Means | With all these precautions to make a big gun strong enough to withstand pres- sure, the result would not be successful except for the extreme care in making the steel and its “heat treatment.’’ Steel in its crude state, or when originally cooled from its molten or liquid condition, is one mass of crystals relatively large and in- timately knit together. But when these crystals are large the steel is not as strong as when they are small and fine. The object of heat treatment is to render all Forging a Great Gun = SSE eee — Fen a - mi, Mme: Maa Pa a in. niin iy san d } } a One of the tremendously powerful “mechanical blacksmiths” or hydraulic presses which work down to smaller sizes the white hot large steel blocks or ingots. Gradually they are thus converted into long cylindrical pieces, the embryo or starting point of the gun itself. These immense presses are worked by levers which cause the ram in the center to obey the will of the operator. Cranes and mechanical apparatus, as shown, can turn this red hot block over®and over at will Cooling the Steel Under Pressure ad UW ASN ' ‘ z a / We \ \\ \ \ WS MMMM ‘ PAY Steel, when it cools, contracts to such an extent that a hollow space is always left in the center of the upper part of a large body of metal. The extent of this cavity, or ‘“‘pipe,’” is greatly reduced under pressure so that this natural contraction is taken up or prevented and a solid block obtained. The picture represents what is known as ‘a fivid compression plant or press in which hot steel can be allowed to cool under a cconsta>tly increased pressure 46 Popular Science Monthly 47 Making the first cuttings from a large round forged steel block which is to become part of a big gun. The work is being done on a large lathe in the machine shop plant. ingot or block can be seen just at the edge of the picture. the crystals fine or to “refine the grain”’ as it is called. To do this the steel gun in one stage of its manufacture is heated until red hot throughout. In this condition it is suddenly cooled: by lifting it high in the air and lowering it with a big electric crane down into a big tank of oil. It is thus suddenly cooled and the crystals made very small. But the gun in this condition is so hard that it has to be tempered or annealed. This is done by heating up the steel again to a lower temperature and cooling it slowly. This operation greatly toughens and strengthens the steel. There is something wonderful and also mysterious about the flight of very heavy shells and the energy that makes them go. It is, of course, the charge of powder in the back end of the gun that does the work. An electric spark explodes the charge, which is usually a nitro-glycerine com- pound. If gunpowder increased in the requisite quantity, the gun itself might burst before the shell was driven out; modern smokeless powder burns more Another steel Powerful cutting tools are necessary gradually. You can light a cigar with it, so slowly does it burn. The principle of the phenomenon is that the explosive is, when ignited, at once changed to a gas which, confined in a tiny steel chamber, must find its way out. As it does, the shell is forced out by the only opening left. The life of a big gun is surprisingly short. The powerful explosive, such as cordite for example, creates an intense heat on the walls of the cannon. This gradually melts at each shot a little of the inner surface, constantly wearing away a thin layer of the steel. It is sometimes called the erosion of a gun. This erosion, or wearing away, is so persistent and gradual that the very big guns can be fired only a limited number of times. It is said the actual life—that is the sum total of the time consumed in the firing of the shots as long as a gun lasts—is really in some cases not more than a second or two. After that a new steel lining is put in. Many things have been tried to reduce erosion, for the cost of one large gun runs into many thousands of d6llars. 48 Two thin coatings of plaster of Paris are washed lightly over snugly fitting jerseys The cast comes off in sections and is then filled in on the inside with papier maché Making a Second ‘‘Self’’ for Dressmaking Purposes ITTING is the hardest and most tedious part of dressmaking. Manya yvoman could make her own clothes and save a good percentage of her pin-money if she were sure that the garments would have the proper ‘‘set.”” There are various kinds of dress forms on the market to meet this need. One of them, recently invented by Wayne T. Sachs, of Los Angeles, Cal., is cast on the lines of the living figure to be fitted. To make it, two jerseys are fitted snugly over the body. The outer one is made in two sections connected by strips of tape. After the jer- seys are ad- justed, a thin The little automobile is a single-passenger model, but it is capable of accommodating a trailer Popular Science Monthly wash of plaster of Paris is applied to the outside. When this is partially dried another coating is applied. After this second coating has dried a little, the tapes connecting the two portions of the jersey are untied, and the two parts, front and back, are taken off separately and allowed to dry thoroughly. The shape is then filled in on the inside with papier maché. It requires only about an hour to make the form, which is less than is often required by the modiste for one fitting of a fashion- able expensive garment. Casts of the arms may also be made and attached to the form, so that the figure is complete. The mold may be used on any lay-figure standard or it may be set on a table or stand of convenient height. The only objection to it is that it is not adjustable. If the stout woman makes up her mind to reduce and accomplishes her pur- pose she will have to order a new dress-mold in consequence. Similarly, the too-slender woman should not use her dress- mold after she has been through a building-up course of treatment, until she has had its lines altered. The Youngest Manufacturer of Automobiles LTHOUGH only twelve years old, Clarence Suttcliffe, of Aurora, Ill., has constructed a real automobile which makes record time for its size. His materials were obtained .mostly from scrap heaps. His one purchase was a one-quarter-horse- ° power gasoline engine. The machine is belt-driven and will make a speed of fourteen miles an hour. In the absence of a clutch, the young manufac- turer shuts off the engine by means of a foot- lever. When rounding cor- ners he presses down on the lever; this -shuts off the spark. Thecar iscalled “‘G-3.” - stocking can be laundered -on and the stockings are Fashions. It Irons Stockings HIS is the day of conspicuous and elaborate hosiery. The laundering of stockings and socks has had to keep up with the fashion. Formerly it was necessary only to smooth out the wrinkles, regardless of any ‘“‘shine” that might < Popular Science Monthly ~ 49 The Laundry canpe Pace with the An Alarming Alarm for the Burglar.. He Could Never Turn It Off N entirely new burglar alarm which prevents a burglar from opening your window stealthily at night has _ been patented by William Connoly, of New York. Once the window is.started upward, the noise of the alarm be imparted by the iron. In home laundries the queen of the washtubs often considered it un- necessary to iron the hosiery at all. Now, however, a fine in such a way that it will look exactly as it did when new. A _ stocking ironer has been invented which employs forms over which the wet stockings are drawn after they have been washed and rinsed. will upset the nerves of the burglar himself. The alarm is extremely simple. An automatically locking push-button fits into the window frame just above the lower win- dow. A flat-head bolt is screwed in back of this push-button and makes contact with the iron mounting in which it slides. The bolt and the button are normally pushed in their outer- most position by a spring The steam heat is turned — dried and ironed at the same time from the heat inside the forms. In this way the original shape and luster of the stocking is retained and any embroid- ered design is brought out in relief. - The ironer is intended principally for use in large laundries having steam power, although it can be adapted for the home laundry. The forms are of all shapes and sizes. They prevent shrinking of all-wool stockings, also. at the same time by steam heat wai: Sok ee , vw 6 ae... pnemmmemeniaell Raising the window pushes in the button, closing the alarm circuit inside the mounting. Should Mr. Burglar jimmy the window, the button is pushed in as the window is being raised. Immediately the head of the bolt passes a contact finger. The bell circuit is thus closed through the bolt and the finger. Thereupon the righteously indignant land- lord reaches for his gun. The iron finger prevents the button from being brought back. So if the burglar supposes he can turn off the alarm before anyone inside hears it, he will be horribly disillusioned. Only a person familiar with this alarm can turn it off. The flat head of the bolt contains a slight notch. By turning the button in a certain position, the notch will come opposite the finger, and the bolt-head can slide through. Simple though this is, the burglar would never think of doing it; neither would he have = time enough to do it if it should flash across his mind; for there is nothing faint- hearted about the alarm. Its evident intention is to arouse not only the mem- bers of the house- hold but the police- man on the beat and all the neighbors on the block or in the Vicinity. Steam inlet Fighting the Big Guns from Balloons The sausage balloon is provided with a wind bag which keeps the balloon nose to the breeze. Steadying cones are also fastened to the rope, kite-tail fashion HERE never was a time in the _ history of fighting when a general did not envy the birds. If he could only hover over his enemy and see for himself what was going on! Since he could not do that, he used such makeshifts as he could devise. But the first real spy- ing on the enemy came when the balloon was invented. Someone asked Benjamin Franklin what he thought of it. ‘‘It isa newly born child,”’ he replied. That was non-committal; also prophetic. At all events, the F rench revolutionists, daring adventurers in war as well as in politics, adopted the balloon at once as a superior substitute for the old watch tower. They held it captive by a rope, quite in the best Twentieth Century way, and used it very effectively in battles to drive home revolutionary truths. Their ‘“‘aerostiers’’ even dropped their messages on long streamers of Pape weighted with lead. When the dirigible and the.airplane came, it was popularly assumed that the observa- tion balloon was to become as extinct as the dodo. Indeed, in the early days of the present war, observation balloons were never mentioned in the despatches as were the dirigibles and the airplanes. But as the war developed, as weapons changed their character and became even medieval, as all Europe was converted into one huge fortress, as warfare changed into a con- tinuous siege, as guns of unprecedented size and power were brought into action, lo and behold, the old captive balloon came into its own again with a vengeance! It came back with other discarded and ancient weapons—with steel helmets, and with Why the observation balloon still plays a part in war despite the airplane and the dirigible By Carl Dienstbach hand grenades thrown from trenches. Battles of to-day are won by the most terrible of systematic artillery bombardments. The captive bal- loon, connected as it is with a bat- tery by a telephone wire running through the holding cable, renders it pos- sible to correct the range instantly, and therein lies its advantage over a constantly moving airplane. The balloon is at a disadvantage because of its distance from the enemy—a distance dictated by con- siderations of safety. But that disadvan- tage is compensated for by supplementary information gathered by ,the airplane. An active enemy rarely permits an. ob- servation balloon to stay aloft for even an hour. But as a rule the balloons are so far behind their own lines that they may stay up fora whole day. During the re- cent engagements around Arras, Sir Doug- las Haig reported that he had shot down every German balloon over a front of per- haps twenty-five miles. Such wholesale destruction of observation balloons is pos- ble only under exceptional circumstances. Ordinarily the ranges are too great. But artillery is not the only dread of the bal- loon. Small, wasp-like airplanes darting in and out with bewildering rapidity, throw firebrands on the thin bladder filled with gas, which explodes even more easily than ‘dynamite. Threatened either by bursting shells, or by these firebrands, the obser- vation officers in the baskets of the bal- loons, must jump for their lives. The peculiar sausage-like captive bal- loons which are now used by all armies, were invented in 1894 by two German army officers. In Germany they are known as “kite balloons.’”’ A kite balloon consists of an elongated gas bag with an arrangement by which the wind, caught in internal air compartments by check-valves, distends and stiffens the balloon against itself. A regulation kite bridle is used. The balloon is provided with a fin, consisting of an appended air bag, like a modern kite, and even with a regular wire-tail consisting of a rope having a series of steadying cones. 50 a ee om ° a — oe ee: See a, a i s ss cuibeeanes | | Photos © Int. Film Serv. In the oval: An officer in the basket of a sausage balloon. Telephone receivers are strapped to the officer’s head. The wires run down through the rope to the ground. By means of the telephone he communicates to the battery the effect of each shot. Upper right hand picture: The man who is sent aloft often in the observation balloon becomes a far more daring parachute artist than any man who ever risked his neck at acounty fair. The parachute was intended to serve as a safety device. In the | whole history of aerial navigation, it never saved a single life in a cross-country journey. War, alone, justifies its existence. The war parachute is of the ordinary type made familiar by the county fair as seen in the bottom picture. Half an hour after an officer has dropped to the ground to save his life, he is up again in a new balloon ——} — = A Housekeeping Made Easy A beater attach- ment on the ordi- nary potato masher which adds greatly to its usefulness ture for holding windows open for ventilation and pre- venting them from being opened fur- ther by intruders With one revolution of the crank a seed is removed from a cherry without losing any of the juice. The seed is dropped through an opening in the bottom of the tray into a separate dish from that which receives the pulp ‘A With these sealed water jars, butter, meats and other perishable food- stuffs can be kept fresh and sweet without ice Here the brush of the dish washer is in use. There is a soap compartment just above the bristles. The | hot water passes down through the soap to the brush and plate surface Kettle made in aluminum having a double bail with handle so ar- ranged that it is self-tilting. The contents may be poured out or liquids drained off of vege- tables without removing the lid The usual difficulty of directing the breeze from an ordinary electric fan in the larger sizes is easily obviated by the ball joint in the stand. The fan may be set and clamped at any angle 52 A dish washing device which has a small opening like a nozzle through which clear. hot water may be thrown on the dishes by means of a thumb-operat- ed valve. A brush at one end completes the clean- ing process expeditiously ” — er Ty Housekeeping Made Food is put into the dog-crate shown at the left, through a small door in front ee ee A crate for shipping dogs in safety and comfort with- out danger to the express- man and porters who must handle it on the journey, Riidalar oth with draw string through six brass rings makes a convenient bag for odds and ends A hat protector made like an envelope. It may be carried in the pocket or handbag as a “prepared- ness”? measure to be used in case of sudden rain ey aS, oo Qs NT te Sivwaae t A shelved wire mesh rack fOr. ¢co.-n.- veniently keeping the different vege- tables separate and where air can circu- late through them to prevent decay ‘Tightenin buckle : j Supporting frame A light detachable fan for a sewing machine flywheel 53 A neat appearing and sanitary dog kennel made from a barrel. Thereisa shaded resting place un- der the frame support A hanging or counter dis- play stand for grocers and fruiterers. It permits free air circulation on all sides A deodorizer of ornamen- tal design for hanging on a wall of the sick room or to counteract the musti- ness of a roomthat is to be kept cld8ed a long time This motion picture camera is smaller and lighter than the professional machine and re- quires no tripod. It is aimed from the shoulder through an open finder. The substitu- tion of a motor-drive for the hand crank makes it possible to follow the movements of an object. Current is supplied from batteries in the pocket \ \ YHY is the phonograph in every home, but not the motion picture? Chiefly, because celluloid films are highly inflammable, because rooms must be darkened, because screens must be set up, in a word because elaborate prepara- tions must be made. The making of motion pictures is hardly within the pos- sibilities of the average amateur. In pro- fessional motion picture photography, ex- tremely accurate mechanisms are employed at almost every step. Perfect results depend on the accuracy, judgment and experience of experts. p The expert camera man is not called upon to develop his film. Developing processes are often as unfamiliar to the photographer. as pho- tography is to the de- veloper. Fixing and drying the film is a separate branch of the process. -Print- ing of positive film from the negative vequires the at- tention of skilled mechanics who may be entirely ignorant of cam- era work or developing. Projection of the completed film is a mystery to almost the entire productive force; for some knowledge of electricity and arc-light- ing is necessary. The operator must be alert and cautious. He must Paper film 100-foot jEccentric Claw > | drive Electric mo 4000 revo! Mites per minut 54 reelcase ™. Take up reel Interior of the camera. magazine will accommodate 100 feet of film which is advanced by means of a single claw drive Home-Made Paper Motion Pictures A safe and sane method by which you can make the pictures and exhibit them to your friends By Max Fleischer be entirely familiar with his machine and its dependent devices. Thousands of feet of highly combustible film must be driven directly across the path of the blazing arc-lamp’s concentrated rays. The speed of the film itself is all that keeps it from being instantly consumed. Failure of the drop-shutter, as the film slows down, would result in a blaze. The operator must be specially trained. As a rule, theater pro- jection machines are quite safe—that is, safe in the hands of an experienced operator. In view of all the knowledge and ex- perience required to go from A to Z in the production and projection of motion pictures, considerable credit is due Mr. Hartwell W. Webb of New York, inventor of the home projector and camera, for his success in simplifying and reducing the cost of the process. In addition to making its operation safe, he has practically suc- ceeded in leveling the complete apparatus to the home basis of the phonograph. Mr. Webb has produced not only a motion picture camera which is almost as simple in operation as the kodak, but also a projector which requires little more knowledge to operate than the magic lantern. All fire danger has been eliminated by the perfection of a paper film. Incidentally, he has found the paper film to be far more durable and economical celluloid. His camera, which than the Feed and take i acy ™up sprocket End section of spring belt reduced, forms a threaded engagement iy ase Flexible A spring belt, reduced at one end to fit the opposite end of the belt, makes a threaded flexible engagement The feed weighs about fifteen pounds, is considerably - smaller than the professional machine and every part of the surface. is operated by a small electric motor. A cell of dry batteries carried in the operator’s pocket supplies the necessary current. The Popular Science Monthly 55 been perfected in which the negative is chemically converted to a positive with remarkable results. One solution removes the silver nitrate from the negative; another bleaches the shaded and dark portions leaving the film Developing the film in the form of a coil re- duces the quantity of solution required. About three quarts of solution will de- velop 500 feet of film Below: Method of sion. A frilled cellu- loid strip is used as a separator between the layers of coiled film blank. On exposure to light, the color values are reversed, the most delicate tones and gradua- tions being retained in the color rever- sion. By converting the negative into a posi- tive, it is evident that only one fin- ished positive film can be obtained from camera can be loaded in day- light. No tripod is nec- essary. The amateur py corvsated = photographer separating stip who has de- veloped his own films will require no ad- ditional knowledge for developing the paper motion-picture film. The film is wound around a wood core together with a celluloid strip frilled on the edges. The frill acts as a separator be- tween the layers of the film and at the same time allows the de- veloping solution free access to The film is rinsed, fixed and washed in the usual manner. It is dried on a collapsible wooden drum. An important feature of Mr. Webb’s process is the produc- tion of the positive film. The paper negative film is not trans- parent; therefore a positive film cannot be made by contact. Even if it were possible to do so, it would not prove practical for each negative. For quantity require- ments, a number of experiments have been made with the half tone or engraving proc- ess as a printing medium. In this process, the positive film is reproduced on a sensi- tized copper surface and etched with nitric acid to produce printing plates. In this manner an unlimited number of positive prints could be produced for circulation purposes, paper and ink being the only material required for the work. As the initial outlay for the half tone plates would be large, this method would prove practical only for quantities running into the At left: The screen on which the picture is thrown is in a shadow box Collapsible curtain Jdgren Translucent Cabinet cover Reflection trom mirror to screen Mirror Rays from lens to mirror a} Shutter | Electric lamps i J nh ae Light spot on film from ~ ring of lamps Lamp ring ie: Lens : ‘ -— oo Rays from Ly" Kore) ig film to lens na I 4 an @) the amateur, because motion picture film printing by contact is necessarily done by machinery and entails the additional ex- pense of another length of film. A much simpler method has At right: The projec- tion principle of the cabinet explained. The reflecting mirror is disposed at an angle of 45° under the lid oo : ead ae 56 Popular Science Monthly thousands.’ One hun- dred feet of film could then be sold for a little more than the cost of the paper; or rented for much less. Two types of pro- jectors have been made. One model is intended for use in schools and churches, while the other is suit- able for home use. .The operating principle of both types is the same; there is a difference only in the range of focus. The home model is built into a cab- This form of projector is intended for small as- semblages. It may be operated by hand or motor inet, resembling that of a phonograph. In fact, phonograph cabinets with slight interior alterations are at present being utilized to assemble the home projector. Paper film being opaque, it must be reflected, rather than projected on the screen. In carrying out this principle, the projection machine is placed in the lower part of the cabinet with its lens directed upwards towards the lid. Fixed directly over the projector is a brace containing a ring of nitrogen lamps and reflectors which are arranged to throw their concen- trated light on a spot over which the paper film passes. Since the nitrogen lamp is very cool, there is no danger of burning the film. ‘The picture is reflected upwards Reflectors : from film Electric lamps to lens Light rays to film 2 @/ er be je! Light rays Paper film to a mirror disposed at an angle of 45 de- grees and thence to the screen attached to the lid of the cabinet. A small motor drives the pro- jector mechanism, elec- tric current being sup- plied to the motor and the ring of lamps from . any convenient lamp socket. In addition to the animated pictorial rec- ord that can be pre- served of family and Pictures of absorbing in- terest can be made of friends and members of one’s own family friends and of in- teresting incidents of sentimental value, Mr. Webb proposes to estab- lish a_ circulating library which will furnish by mail, at nominal cost, films of current interest occurring the world over. Judg- ing from the popularity of the motion picture theatre, there is every reason to believe that the home picture cabinet will prove as popular as the music cabinet. It can be made to harmonize with the ‘surrounding furniture, and is as ornamental as the pho- nograph cabinet, with which it is identical in appearance except for the screen on which the pictures are projected. This screen ‘is collapsible when not in use. It is set in an ornamental frame which serves as a shadow box, so that the pictures may be shown in broad daylight as suc- cessfully as they can at night or in a darkened room. At left: In- terior of the protecting mechanism Circular arrange- ment of the lamps j : J . ‘A New Type of Caterpillar Motor-Truck. It Can’t Stick in the Mud HE novel commercial vehicle shown in the accompanying illustration differs Popular Science Monthly 57 The Convalescent Soldiers Are Ingenious Toy Makers HE war has indirectly been the cause of driving many erstwhile clerks and from other forms of cater- pillar tractors in that it has one caterpillar or track-lay- ing unit in the rear and two wheelsin front. It is substan- tially a three- wheeled vehi- cle with the track-layer as mechanics but now soldiers into the ranks of the toy makers. The invalid soldier finds not only employment for his en- forced idle hours but a certain amount of recreation as well in de- vising original the third wheel. It has The track-laying caterpillar motor-truck is a three-wheeled a much greater vehicle, with the track-layer as the third wheel speed than a, conventional track-laying tractor. Fifteen miles an hour is within its capabilities. It is especially intended for hauling trailers over rough country roads, but it can run over improved state highways by reason of the rubber tires on its front wheels. The front wheels are of steel with wide steel tires. The rubber tires are fitted in the center of the steel tire. When running over good roads the front wheels are supported toys. In order to make a really successful toy, one must needs have a more or less intimate~knowledge of child-nature. The men who made.,.the designs shown in the accompanying photographs must have had in mind a picture of some toddler leav- ing all the expensive toys that Santa Claus had left around the Christmas tree and going persistently back to mother’ s old dust-brush or broom. The articles pictured, the work of maimed or blind soldiers, were exhibited at the Lyons Fair. Black on the rubber tires, but when soft roads are encountered they sink into the ground. The wide steel tires then support the trac- tor and prevent it from being mired. If any of the trailers should stick in the mud, a rope around the winch on the and white paint and large shoe-buttons for eyes converted the long-handled brushes and brooms into in- dividualities, while clever carving in con- junction with paint and shoe-buttons and wooden wheels made stands for other types of brushes, which tm- track-laying unit is employed to extricate them. Although this truck is equipped with the caterpillar unit it would not be possible for it to negotiate shell craters and deep trenches as readily as its predecessor, the British tank. Hence it is not designed for war service. © Int. Film Serv. were converted The long-handled brushes and brooms into black and white paint and shoe buttons for eyes. They required some clever carving too mediately bccame "i fierce and wonderful i/ animals with accom- modating holes in their noses for strings. But the toys do not lose their utilitarian quality permanently. When they. are no longer needed as play- things they may be re- tugned to their hooks in the kitchen. individualities «by 58 _A small quantity of the - ‘solution is forced into the ‘tire. . When the wheel re- _volves, the fluid spreads in’ a. thin film over the pores of the inner lining A Solution Which Promises to Solve Some Tire Troubles SOLUTION which is injected into the inner tube of an automobile tire through the stem is said to keep the tire at normal inflation and to make it practically puncture proof. The solution lies in a fluid state at the bottom of the tire, occupy- ing only six per cent of inner space, except when the car is in motion, when centrifugal force carries it around the tire ina thin film, thereby sealing all porous places that cause slow leaks. The fifty or eighty-pound pres- sure forces the solution into every infinitesimal open- ing where air leaks out, and at once seals it. Popular Science Monthly According to chemists’ reports the solu- tion does not injure the inner tube in the least, but is, on the other hand, a preserva- tive of rubber. Under-inflation is the cause of the majority of tire troubles. With the new solution the proper air pressure is maintained at all times in the inner tube. On Land a Submarine Travels at Tortoise Speed O her great surprise, the U.S. Sub- marine H-3, of the Pacific division, woke up one day to find herself high and dry on the sands of Samoa Beach, California. It was not exactly the proper place for — a perfectly respectable subma- rine, and plans wereimmediately devised to launch her. The best launching place was Humbolt Bay, nearly a mile distant, where the land goes down rather ab- ruptly from the shore. So the subma- rine was jacked up and laid upon a wire cradle formed between two huge logs. The cradle and its burden, wheeled upon small logs as rollers, were then moved slowly forward by hauling on a block and tackle. This is the first authentic report of a bona-fide submarine taking an overland journey. As a land animal, however, the sub- marine is not very spry—she makes about one hundred and fifty feet in an hour. Under water she travels at from six to eight miles an hour. Hereafter she will prob- ably be more careful about keeping away from shore and out of the path of breakers and inrushing tides. When the U. S. Submarine H-3 became beached, she had to be jacked up on a massive log cradle and pulled on four sets of huge rollers to a suitable launching place nearly a mile distant Popular Science Monthly Typewriting in Code on a Specially Constructed Machine HE war has brought forth many devices for communication in code; and many different codes are used in the different departments, as well as among individuals. The invention of a typewriter which will print in code follows as a natural con- sequence; for time and speed cannot be sacrificed continually, even in the interest of secrecy and safety. The code typewriter is a complete type- writer, standard keyboard, with nothing in its appearance to indicate that it is not an ordinary typewriter. On this machine a stenographer may produce the cipher writing with the same speed as though he were writing in English. It is the inven- tion of Edward Hebern, of Oakland, Cal. All the characters of a standard keyboard may be represented, in the cipher of letters. In placing figures and other characters not letters into cipher the shift. key is not operated, but in order to translate them out of the cipher it is necessary to hold down the shift key in copying the cipher letters that représent figures and other characters. For the receiver of a cipher message to ascertain what letters represent other characters than letters, he simply copies the whole of the message. The parts repre- sented by figures remain in cipher. He then sets the shift key and recopies those portions; the result will be that the figures or other characters will be printed. An unlimited number of different codes may be used. A change of code is effected without changing the position of the letters on either the keyboard or type. The code is changed by means of a small aluminum de- vice called the ‘“‘code bar,” weighing about one ounce. It is simply withdrawn from a slideway and another bar, set in a different code, is in- serted. The code bar contains twenty -six graduated letter blocks. By unscrew- ing a thumbscrew and moving the let- ter blocks to a differ- A bunch of fire-crackers to scare away the malicious spirits of storms and submarines Fire-Crackers: A Chinese Protection Against Submarines HE Chinese are superstitious. They are constantly trying to slaughter the myriads of malicious spirits and sprites that are supposed to flutter everywhere, even under the bed or between the cracks of a floor. Fortunately, it is a comparatively simple matter to put a couple of thousand sprites out of the way in one fell swoop. All you need do is to explode a fire-cracker. The evil spirit and malicious sprite can’t stand noise. It irritates them to dis- traction. If loud enough it kills them. Consequently, when a Chinese crew makes ready to hoist anchor the first cere- mony is to unpack the fire-crackers and slaughter the evil spirits with a five- minute bombard- ment. Nowadays ent position a change is made. The code is changed by means of a small code bar having twenty-six letter blocks great quantities of firgworks are carried. 60 The new life-guard boat which can not capsize. The man lying down is looking through, the glass bottom to locate bodies A Life-Boat That Cannot Capsize or Sink NEW life-boat built along the lines of a big surf board, has proved so satisfactory that it has been officially adopted by the city of Long Beach, California. The boat, sixteen feet long, forty inches wide and four- teen inches deep, is non- capsizable and self-draining, and is the invention of A. M. Nelsen of Long Beach. It has many advantages over the skiffs now used by the municipal life-guard squad of that city. It can be put through the heaviest surf without waiting for a calm. It has air tanks on both sides, at the ends, and down the middle, and has a glass bottom through which bodies that may have sunk may be located. With one man paddling, and the other stretched at full length peer- ing through the glass bottom, a body can be located in twenty feet of water and brought to the surface by means of grappling hooks or by diving after it. The boat is propelled with double-bladed paddles by two guards. It can make a speed of six miles an hour, and will support twenty people. Air-tight compartment: Construction | of wood, metal |: covered F The buoyant air tanks are - at both sides, at the ends, and down the middle. Above: Launching the boat in a heavy surf wagon without Ae Cleaners down into handling Popular Science Monthly A New Machine Husks a: Bushel of Corn a Minute in the Field NEW type of corn husker which promises. to relieve the farmer of the tedious and disagreeable work of husking corn in the damp fields has just been completed by W. H. Tschantz, of Ohio. The apparatus is driven by a gas en- gine and not only husks the corn but deposits the clean ears in a wagon bin by means of an elevator forming a part of the device and binds up the husks and silks in bundles like wheat, eliminating all litter and loss. . t) The apparatus consists of a small four-wheeled wagon — on one end of which are mounted the gas engine and a suction blower, with the husker and binder at the other. In operation the wagon is drawn from shock to shock by horse or mule power. The un- husked corn is deposited on one side of the binder. The shock is first torn into small bundles and thrown on the feed board, which carries the bundles up to a series of hori- zontal rollers. Most of the husk is removed while passing through these rollers, and the ears are dropped on to a pair of rollers beneath the husking rolls. Here the silk is removed, after which the clean ear drops through a trough into the base of the elevator, which deposits them in a wagon or other waiting receptacle. Path of silk from bottom trough to binder f™ . ot \ ‘Sy ” Cleaners ed up elevators The bundles of corn are thrown on the feed board which carries them to a series of rollers which remove the husks Binder side’ 3 Popular Science Monthly 61 a pom gs French Official Photo Millions of shoes worn to all degrees of disrepair, waiting to be sorted, patched and. soaked in oil. Scraps of leather are passed through an ingenious cutter and converted into boot-laces The ‘*Shoe Hospital’’ of the Allies. Not an Inch of Leather Is Wasted N a recent issue of The New Republic, W. M. Meredith makes the following reference to the shoe-repair shops of the Allied Armies. “Entering another shop we find huge stacks of worn-out boots in every degree of disrepair. These are first sorted out like patients in a hospital, according to their various injuries. Those requiring new soles go in one direction, those which must have new toes or sides Not the Latest Style in Hats—Just a Hair-Drying Frame HE artist who made the “human interest’? drawing of the hair-drying frame illustrated below is evidently a bachelor who has spent all his days in an Eden where there were no Eves to go about periodically in low-necked kimonos and wildly flowing tresses during the process of drying and airing the hair after a shampoo. However, he has shown the frame clearly. It is made of wire netting, and buckles around the head with an are passed on in another. Here the boots are re- fitted completely, and finally go into a bath of hot oil where they are thoroughly soaked. If any British soldier of the three million-or so in France expresses a wish to have a certain pair of boots returned to him that fit him with com- fort, he is certain of getting that same pair back.” Think of that ‘Adjustabie and adjustable band. The hair is drawn up tight to the crown of the head after the last rinsing and a perfunctory drying. Then the frame is ad- justed and_ buckled around the head, and the hair is spread over it in all directions, so that the air can circulate through it thoroughly. To the professional hair- dresser, with an electric fan for the drying, such Wire netting frame in connection with our photograph above! The hair-drying frame is of wire net- ting with an adjustable head band a frame should prove invaluable. 62 Popular Science Monthly A Drawbridge Gate Which Will Stop Any Automobile A runaway car striking against this gate would be stopped by the cush- ioning of the huge gate- springs in the cylinder ESPITE even the massive iron gates that swing across a road when a drawbridge is opened, automobiles break through occa- sionally and plunge into the river below. Such accidents occur when the brakes jam. Here was an op- Gate separated but locked N Direction of impact still further absorbed as the spring is further compressed. Before the'car has gone a half dozen feet forward, all of its “push” will _have been completely destroyed without producing any undue strains on the gate. The method could be relied upon to stop anything short of a railroad train! The Wooden Hand Rammer — A Survival of the Fittest 1D apa the last five years the electric chain rammer | has disappeared from the tur- rets of modern warships. A — short circuit on one of the battleships almost led to. disastrous consequences. In other cases a tempora- ry breakdown spoiled the turret’s chances in record firing. Gradually the old hand rammer, which in principle has changed little since Nelson’s men rammed the round shot home in the muzzle loaders, has won back its supremacy. The turret of a Dread- nought is filled with other electrical de- vices, but the wooden rammer is the one bit of equip- Spring in all cylinders compressed Compression spring portunity for an in- ventor. It was seized by Jacob Harsen, a highway engineer of ‘New York, who has invented a cushion lock for gates. Four huge ‘“‘locomotive’’ springs are mounted inside of four cylin- ders at the ends of the swinging gates on each side. ‘The cylinder plungers, which work against these springs, form one piece with the gate coupling, which is locked by the gateman when the draw- bridge is about to be closed. When the automobile strikes the gate at high speed, the huge springs are slightly com- pressed ; then the gate “‘gives”’ away gradually. The energy , of the automobile’s impact is Gate locked in normal position, Detail of the cushioning spring. The cylin- der plungers which work against these springs form one piece with the gate coupling ment that has sur- ‘th vived from the days of wooden ships, so far as the turret is concerned. The electric chain rammer was. placed directly in the rear of and parallel to the bore of the turret gun Our Unsinkable'Torpedo-Proof, Cargo Fieet The boats will be patterned after the ordinary gy oil-tanker with its hull divided into a dozen or more tight compartments By Joseph Brinker UD) ihet's the i Yes, practically. Mae ets ee ae = That’s the kind of ships it is now proposed to build for Uncle gen Sr Sam’s fleet of freighters to thwart the | Zz Sone ee ks torpedoes of the German submarines. = bee at Of course no vessel afloat or to be launched in the near future will be unsinkable if a sufficient number of torpedoes are exploded against her sides. Even the latest battleship is not immune. But Uncle Sam’s new boats will have no unprotected portions of the hulls, and it will take at least two and perhaps three well-aimed torpedoes to sink one of them. The new type will be fully armed. It will be of steel construction and patterned after the present-day oil- tanker which is practically immune against “single torpedo attacks except in the way of the engine and boiler rooms. If struck there she is done for and settles by the stern, with no power to “oe ‘The new boats will have fuel-oil tanks extending clear around the ship from main deck to main deck, from the front of the boiler space to the rear of the engine room. If a torpedo strikes her there and blows a hole in her outer skin, the inside of the tank will act as a new hull to keep her afloat until the submarine rises to view her prey. Then because of her arma- ment, the ship has a chance to de- stroy the submarine. None of the oil tankers have been sunk so far in the war by one torpedo, unless hit in the engine or boiler space. Applying the Lesson Taught by the Oil-Tanker The bulk oil in the tankers is carried in a dozen or more separate tanks or compartments into which the hull of the tanker is divided by an oiltight longi- tudinal centerline bulkhead and many transverse bulkheads. This is why one = ¥ A billion dollars’ worth of shipbuilding means that the proposed ships will entail the production of steel enough to make two Woolworth Buildings, each 792 ft. high 64 Popular Science Monthly B EXPANSION SPACES T0,ALLOW OIL 10 EXPAND pasa oe SECTION THROUGH BOILERS OSA NPR ON By SECTION THROUGH t : TYPICAL TANKS y, ENGINE Fa | A ff— | @l) \¢ joners _|watcnes Fear O H 00000 a | | | —- ——. a 7 | re CARGO OIL pe Oo lo FUEL PUMP WATER OIL |] Now ] NOT | No} Nos | No4) No.s| no. {wax ROH WATER UNPROTECTED ENGINE AND++ SEVERAL OF THESE TANKS CAN BE PUNCTURED AND VESSEL =| {FORE BOILERS in STILL]FLOAT PEAK {\ fhm ——f Fiza BRIDGE B K > 2 [ae | SS T Ch BULK [CARGO NO.7 NO6 NO.5 | NO4 NO.3 No.2 | NO} |WATER SPELRERLURRLERARGERER HORT OREREEE! LULL TTT Tt nes m§£,: FUEL OIL.IN TANKS ONJ~SURPLUS FUEL OIL +1 : TECT-BOILERS AND [8 ENGINE IA 2 The typical oil-tank steamship shown in section at the top and the proposed freighter beneath it indicate the great similarity between the two types. The oil tanks are practically made over into cargo holds. The small transverse section of the boiler and engine room of the upper diagram shows its vulnerability to torpedo attack in that portion of the ship. The lower diagram shows how the vitals in a similar section of the proposed ship will be protected by means of fuel-oil tanks x... In the proposed freighter, the hull will be divided into a dozen or more small compartments and the engines and boilers will be protected by means of fuel-oil tanks extending clear around torpedo will not sink her. A torpedo ex- ploding against the hull of the ship and crushing one or two of these compartments does not sink the ship because of the re- latively small size of the few compartments punctured, compared with the remaining dozen or more that are left intact. The reason that one torpedo is not liable to break open more than two or three of these tanks is that a torpedo is in no sense an armor-pierc- ZZ ing shell of the tank acting as a new hull which passes through the _ sew warerune boat from one Popular Science. Monthly — ae Yl lb If the proposed freighter should be struck in a vital spot she would still keep afloat, the inside 65 and illustrated and described in the June issue of the POPULAR SCIENCE MONTHLY. They will be of steel because there is still some skepticism as to the practicability of the 3000- or 5000-ton wood vessel, because such a ship has never been built before. Questions have arisen as to the racking stresses and strains which would be set up in a ship by the use of un- seasoned wood and as to our ability to raise a suf- ficient army of shipbuild- ers to carry on the work. All of these arguments SLLLLSSLSPLPLPLLPLL.. NEW WATERLINE WATER TIGHT CENTER LINE BULKHEAD side to the other or ex- plodes inside, blowing everything apart. On striking a vessel’s side it explodes and does its work by the rapid expansion and con- cussion of the gases of its charge. The majority of the new boats will be of steel and not of wood as first planned, and the facts that wood OLD wiiicaie! The old type of oil tank sinks ships would at the stern if struck in the probably engine or boiler compartments have shorter —its only vulnerable spots fea eh aw steel ones and be at a disadvantage in com- peting with the steel ships of other nations after the war, seem to have killed the -wooden fleet proposition. Besides, there is no longer a shortage of steel. | WATERTIGH | a LONGITUDINAL Wf CENTERLINE } j= BULKHEAD oN AY ~~ DOUBLE BOTTOM \ FOR FUEL OIL WATERTIGHT TRAVERSE BULKHEAD Hie a? 7 Per i eee es _ =a fren a Ze TANK * be : \ AY WATERTIGHT DOUBLE BOTTOM was ~BOILER e€ space into learly shown the ship. In the broken-away portion of the drawing the bulkheads dividing compartments to reduce the crushing effects of the torpedo’s explosion are very 66 Popular Science Monthly A German Medal to Com- memorate the Torpedoing » of the Lusitania HERE came into the office of POPULAR SCIENCE MONTHLY re- cently a bronze medal in a leather case. It was one of the two medals struck off by the German Government in commem- oration of the act that, more than any other, inflamed the American people against Prussian- ism, the torpedoing of the Lusitania. To - further celebrate the event the school children of Germany were granted a half holiday and the commander of the sub- marine was decorated by the Kaiser. One medal (not shown here) depicts, Neptune seated on a submarine shaking his fist at a sink- ingship. On the opposite side is a_ bas-relief of von Tirpitz. The second medal, which is reproduced here, shows, on one side, the Lusitania sinking, and. on the other the figure of Death selling tickets at the office of the. Cunard Line. The three German words above the sinking ship stand for ‘‘No Contraband On Board.” Examine the illustration and you will see that a cannon and an airplane occupy the deck. Although the Lusitania carried rifle cartridges on her fateful trip, it has been indisputably proved that she carried no weapons of defense or offense. Needless to say, the cannon and airplane are pure inventions. Translated, the legend beneath the ship reads: “The steamer Lusitania sunk by a German submarine May 5, 1915.’ Note that the date is given as the fifth of May in- stead of the seventh. Is - the error a deliberate one? At the top of’ the lower illustration ap- pear the werds, Full-size illustrations of one of the German medals which commemo- rate the sinking of the Lusitania The tea-making machine brews the tea, pours it into a cup and rings an electric bell é; “Business Above Everything.” One person is shown reading a newspaper, evidently the advertisement inserted by “Count von _ Bernstorff, “warning Americans and 3 other neutrals to keep off vessels flying the British flag. Note the man in the rear with the menac- ing finger upraised; also the care-free attitude of the two men in front of him. Beneath the win- dow, in which Death is selling tickets, appear the words, ‘Ticket Office.” In all, 1,198 passengers and crew lost their lives on the Lusitania. In this number are included 124 Americans and 94 children. -An Automatic Tea- Making Machine “TOR-R-R-R! _ ting-a- ling! Wake up! Your teais ready. Br-r-r-r! Time to get up!” This is practically what the automatic tea-making machine does every morning. It brews a cup of good tea, and then it calls its master. It was invented by a young Englishman, George Weddle, of New York, and was designed especially to call him and serve him with his morning bracer. The machine consists of an electric stove, kettle, alarm clock, electric bell, battery and tea cup on a tray eighteen by ten. inches. With these it brews the cup of tea, pours it into the cup and rings a bell until the master wakes up and takes his tea. Should coffee be preferred, there is an attachment to be screwed into the kettle that will act as per- colator. There is also an attach- ment for boiling eggs, so that an automatic break- fast, cooked and served at your bed- side, seems quite possible. The ma- chine may be easily taken apart and put into a small hand bag or traveling case. co >> * - California’s Conception of a “Tank” It was designed for aid in recruiting FS eins somewhat after the famous British tanks pic- tured and described in the May issue of PoPpuULAR SCIENCE MonTuHiy, the California-made tank shown herewith is like its famous prototype in only one par- ticular, that of a track-laying pro- pelling means. There the similarity ceases, for it has not the large upswept track-laying framework in front that has made possible the almost incredible hill-climbing feats of the British tank. Instead it has two track-laying members of the kind used on farm tractors and a small guiding wheel in front. Formidable as it looks in armor A company of infantry using the track-laying tank and with the guns sticking out of its in sham battle on the outskirts of San Francisco turret, a heavy rain would render it use- feet of length in contact with the ground less in actual service. The small wheel allof the time. in front would bury itself in soft ground Obviously, then, the truck illustrated on a shell crater, which its foreign rival would be a failure in the land of shell could negotiate with ease. The large bear- craters between the trenches in warfare as ing area of the caterpillar shoes makes it carried on to-day. However, it served a possible for the British tank to traverse useful end in acquainting our California soft, muddy ground. The pressure issaid infantry with its adaptability as a war to be less than three instrument and in arousing the martial pounds to the square spirit. Theregular army used the tank for inch with the cater- recruiting purposes. It is here pillars thirty inches shown in a sham battle in wide and with rough country in the about fifteen vicinity of San or twenty '. Francisco. Because of the small wheel in front, the tank could not travel in a land of shell graters and muddy ground. It is, therefore, not in the fighting class, however formidable it may appear 67 Popular Science Monthly Importing Japanese Mos- quitoes for Bird Food HE delicate vocal organs of song birds respond magically to special care be- stowed upon the diet. For this reason birds that are cultivated in captivity are fed specially prepared foods de- signed to furnish maximum nourishment with minimum labor of the digestive organs. A food which has been found especially valuable to bird-breeders has for its prin- cipal ingredients Japanese mosquitoes and ants’ eggs. It is prepared by George Jenkins, of New York city, an expert on the care and feeding of birds. The na- Portion of a motion picture taken through periscopes at the bottom of the sea in the crystal-clear West Indian waters Seeing the Wonders of the Ocean Through an Inverted Periscope S is well known, the periscope enables the submarine, while submerged, to see above the surface of the water. Why not invert the periscope, attach it to the side of ocean liners, and thus enable the passengers to study marine growths and fishes? Provided there was sufficient light beneath the water, the inverted periscope might even be used to search for sunken treasure! This is exactly the use to which it is put in the latest underwater motion picture film of the Williamson Brothers, ‘‘The Sub- marine Eye.”’ It will be recalled that the thrilling underwater scenes in ‘“Twenty Thousand Leagues Under the Sea,” were photographed by the Williamsons. In “The # Submarine Eye,” the new under-sea thriller, the invert- ed periscope, as shown in the illustration above, is used to lo- cate a safe containing treasure. In the crystal-clear waters of the West Indies - the audience is shown the marvels of Nature at the bottom of the sea where the light from above is reflected from the dazzlingly white sand. Finally, after a series of harrowing adventures many fathoms under water, the safe is located _ by the inverted periscope. tionality of the mosquitoes is not supposed to make a dif- ference in the taste or digest- ibility of the food. The reason the insects are imported from Japan is that the Japan- ese have a method of catching them in large quantities which as yet Americans have not discovered. In the photograph below, Mr. Jenkins is shown inspecting a shipment of twenty- eight pounds of mosquitoes. The food is intended for soft-billed birds that do not feed on .seeds. Among these are the thrushes, mocking birds, nightingales, tan- agers and many others. In the oval photo- graph an American thrush is shown feeding her nestling with the prepared food. She takes the food on her bill and thrusts it far down the youngster’s throat. | Twenty-eight pounds of Japanese mosquitoes to be used as an ingredient in the bird-food Popular Science Monthly 69 Shall Personal Vanity Prove a _ Handicap to the Government? ECAUSE Dame Fashion, in one. of her capricious moods, has de- creed that platinum jewelry is the fashionable thing to wear, that metal has steadily advanced until to-day it is worth five times as much as gold. As a result all chemical laboratories and institutions throughout the coun- try are greatly handicapped by its scarcity. For producing sulphuric acid, which is an absolute necessity in the production of high explosives, platinum is essential. To relieve the present condition the American Chemical So- ciety suggests that the loyal public refrain from purchasing platinum in the form of jewelry and discourage the use of the metal for ornamental pur- poses. This would be in line with economy, also. Case sewn to pocket *~ The Many-Sided Bathing Cap. Change It to a Suit-Bag When You Travel Home HE convertible bathing-cap of a New i York: merchant has many virtues. Inflated, it serves as a waterwing or a football. Deflated, it becomes a wrapper in which to carry, your bathing suit. . he cap is /f made from strips of waterproof material sewed together to a foot- ball’s shape. It can be folded in half lengthwise by pushing one end down into the hollow of the other end. When this is done it will gasteyer conform to the shape of the ae i. bathing suit. NNE -head and it will be ready for = use as a cap. Straps are at- tached to the side for securing the cap under the chin. A circular bladder can be placed inside this same piece of goods and inflated to change it into a ball for playing on the beach. With a bladder of different shape placed inside it, it can be used as a water- _ wingwithstraps to fasten it around the body. WATER PROOF MATERIAL This cap when opened out forms a bag for the When inflated it is a rubber ball TUBE ‘STRAP This safety chain can be used for securing a wallet toa man’s pocket or to a lady’s handbag The steel chain is wound up on a spring- revolved drum when the wallet is pocketed At Last!—The Safety Chain for Frustrating the Pickpocket ROM sad experience, many a man has learned that placing his wallet in even an inside pocket will not prevent it from being stolen. But if the wallet is attached to the safety chain invented by Law- rence R. Delaney, of Gage, Okla- homa, a pick- pocket could not remove it with- out taking the coat along, too! A fine steel chain connects the wallet with the coat pocket. When you pocket your wallet, this chain is wound up ona spring-revolved drum in a very thin casing which is sewed to the bottom of the pocket. The chain, which has its free end secured to your pocketbook, is about a foot long, so that you can draw it out conveniently. When you return the wallet to your pocket the chain winds up automati- cally. Should a pickpocket attempt to rob you, the tug on the chaih would betray him. OF FLAP BAG Fifty Million Shots to Win a Line of Trenches Nearly nine million pounds of artillery projectiles were hurled at the Germans in a single engagement French Official Photos. Thousands upon thousands of cases of shells are unloaded at the artillery depots of the various armies, after which they are transported in smaller lots to distributing stations Germans were turning out 250,000 shells a day, the British were producing 2,500 in high explosives and 13,000 in shrapnel. Before the war, Germany held an average stock of 3,000 shells for each gun, while France had 700. When the war began, France estimated a daily expendi- ture of 13,500 shells, but before [ the early days of the war, when the sives and firearms worth a half-billion. It is needless to state that the last year has been the most productive of all, not only in the United States and Canada, but in European countries as well. Figures of shell production run into unthinkable billions. For this the tremendous capacity of the guns used is largely responsible. a year had elapsed, she was firing 100,000 a day. According to an official re- port of the French Army Headquarters, the French artillery north of Arras fired 300,000 shots within 24 hours, the total weight of which would be 8,901,000 pounds. During the great French of- fensive of September, 1915, in the Champagne, the French fired at the rate of 900,000 shots an hour—a total of 50,- 000,000 shots in three days on a twenty-five-mile front. The cost of ammunition, considered in the light of its wastefulness, is appalling. A year ago, Canada had con- tributed $350,000,000 worth of shells. The United States had exported ammunition, explo- The shells are housed in rough portable shacks arranged in rows along narrow-gage tracks which lead to the fighting front ~ Cutting Forty Soldiers’ Uniforms At One Time ITH the aid of an electric cutting machine one tailor can cut forty soldiers’ uniforms at one time, and in one ay do the work of one hundred men work- ing with shears. Were it not for the many labor-saving machines in the tailoring business our soldiers might be obliged to wait long for their uniforms. oe At the present time there le are many big tailoring estab- lishments filling rush orders for suits for the Government. They are working twenty-four hours a day, with two shifts of workmen, in order to turn out the work on Popular Science Monthly ‘ 71 It resembles the crude weapons used in the early days of gunpowder and is operated from the shoulder. It has a barrel in the form of a tube about five inches in diameter, at the, base of which an incandescent electric light is located. It is fitted with a stock and there is a trigger which con- nects with a switch that flashes on and off the cur- rent. Current is supplied to the signal gun by means of a cable that enters the stock. On the top of the barrel are sights for aiming the gun. Signals are flash- ed by the dot and dash system, short flashes in- dicating dots and longer ones, dashes. time. The suits are made accord- ing to standard measurements and there is no chance to deviate from the regular sizes. Flashing Signals from Electric- ' Light Guns NOVEL signal gun has been devised by the United States Navy to trans- mit visual signals between ships in a fleet of war vessels that are running without lights, and yet not betray their presence to the enemy. Signals flashed by it are visible only to the ship at which it has been aimed or one in line with it. A tailor operating the electric cloth cutter which cuts out the pattern of forty uniforms at one time Visual signaling between ships at night is usually done by means of lights hung from the masthead, but their operation betrays the presence of the fleet to enemy ships that may benear by. The flashes from the signal gun are only visible to the ship at which the device is aimed or one that may be in line with it either closer or further away from the ship from which the signals are sent. Even though no lights may be showing, one ship knows the approximate location of every other ship when they are in fleet formation and the signal gun may be aimed in the direction of any one of them. When the signal gun is used it is not necessary to “‘call’’ a vessel before sending a message. Knowing that the flashes are not visible to any other ship in the fleet, the men on watch on the bridge of the vessel. at which the gun is aimed are in readiness to record the message as soon as they per- ceive the flashes. The very fact that they see them proves that the signal light is directed at them and that their ship is the one for which the message is intended. The light located within the barrel of the gun is one of great power and its flashes can be © N. G. Mose “Shooting” signals with the signal gun. The flashes are visible only to the ship at which the device is aimed seen for a number of miles at sea, even in cloud¥ weather. 7% ‘ Utilizing Your Player Piano as a Vacuum Cleaner HERE is no better vacuum cleaning pump than the air pump of your player piano. ff s So thought Max ae \ Rothfeld, of Phil- . adelphia, who has patented the dust- filtering at- tachment which will change your piano into a vacuum clean- er. You need only to discon- nect the air pipe leading from the piano bellows, from the air motor. Insert the at- tachment in this, have somebody work the pedals, and proceed with your parlor cleaning. The inventor also suggests that should the air-mechanism of your piano become clogged it can easily’ be cleaned with his device. The device is nothing more than a flexible hose having a wire filter mounted’ across a small dust chamber near its end. Vacuum nipple Conserving the Wheat Supply with Alfalfa SHORT time ago alfalfa, the clover-like plant which grows so abundantly in the West, was considered fit only for feed- ing cattle. Thanks to the re- | searches of the industrial chemist, it is now destined to become one of the most important articles of human food. The present prob- lem of the world’s shortage of wheat—that well-balanced and so essential food—may even be solved with the aid of this form of ‘‘cow fodder.’ Elizabeth C..Sprague, head of the department of Home Econom- ics at the University of Kansas, has found out how a most whole- some flour can be made from the Wacker bar Air motor Flexible hose A dust-filtering chamber fits in the end of a long flexi- ble hose leading from the piano bellows. created by the piano pump draws the dust into the filter Popular Science Monthly ground-up leaves of the hay of alfalfa. By replacing the all-too-scarce wheat flour with a considerable percentage of this alfalfa, a bread can be made which is far more nutri- tious than that made from plain wheat. The high percentage of both body-building and ’ bone-building ele- ments in the alfalfa makes this new bread a practically complete article of food. The bene- fits of its use will ’ therefore be two- - fold :thepresent supply of wheat can be “stretched”’ to feed a far greater num- ber of people, and a more ideal war food can be gained. The suction Making Bad Whiskey out of Good Jam and Potatoes OME German prisoners in the Holds- worthy Internment Camp, in Australia, rigged up astill of kerosene cans, bottles, tin tubes and other receptacles and made whis- key out of jam and potatoes! It was effi- cient enough to meet the demands of the drinkers. Perhaps it was too efficient, for the intoxicated Germans themselves gave the secret‘away. This odd collection of cans and bottles formed an illicit still which was built and secretly operated by German prisoners ‘Transforming a Roadster into a Truck A device which makes it possible for a one- passenger automobile to haul three trailers i ei i Frame of trailer i : 8 positien ti shaped prick The pleasure { “supports... Elbow, At left: The car can be a + various parts changed into Side view 4 Front-view of the wagon- - ; like a one-ton truck and back again into a_ pas- senger car in five minutes wee we i pari in keene position ‘c ing bar to Coes trailer, showing the relation of the small wheel to the body parts Trailer wheels ™ Solid trailer axle SHE conver- sion of a roadster automobile into a one-ton truck and back again into a pas- senger car in five minutes has: been made possible by the use of a patented fifth- wheel device to be set on the rear deck __ of the car to support the front end of a wagon-like trailer. Both trailer and fifth- wheel are now being made as a unit by a New England manufacturer to enable the owner of any roadster to change his car into a work vehicle and back again as often as desired. The fifth-wheel device is mounted on the framework of the car with but six bolts after the rear deck or luggage carrier has been lifted off. The device consists of two wheels of the same size which rub together, one above the other, through lubricating grease. One wheel is mounted on a rock- ing shaft and frame attached to the car, and the other bolted to the underside of the front end of the trailer. To connect the trailer with the car, its front end is simply lowered down on to the wheel on the car. Conversely, it may At right: The fifth wheel device mounted on the framework of _the_ car be removed by simply lifting it up by hand, if empty, or by a jack de- viceif loaded. The fifth- wheel device, which can be lifted easily by one man, is then taken off and the rear deck replaced. The car is then ready to take the owner’s family out for a pleasure trip. The trailer may be fitted with any type of body, according to the class of goods to be carried and principally differs from the ordinary wagon in that it has rubber-tired wheels mounted on roller bearings. These enable the car and trailer to travel at speeds of twenty miles per hour or more and elim- inate the trouble caused by the over- heating of the plain iron bearings such as are. used on slow-speed horse wagons. The jack device for lifting the front end of the trailer consists of a_triangular- shaped framework made of pipe sections. It is pivoted ‘to the underside of the trailer and has a telescoping bar attached to the trailer axle to keep the framework upright when in use. This eliminates the wooden horse formerly used and permits the trailer to be moved from place to place for loading and unloadifig. Do It With Tools and Machines Y&-COTTER PIN CHSHAFT @) CLIP CHANNEL COMPRESSION SPRING A cotter pin extractor that not only draws the pins but straightens the shanks so that they may be used again without any special operation to permit their reinsertion in the opening of the bolt or shaft from which they were taken. The clip for drawing the cotter is worked by a pair of arms between the closing handles A convenient oil and grease cup in which the grease is retained for an emergency. The object of this cup is to prevent the over- heating of the bear- ing should the oil passages become clogged or the at- tendant fail to start the oil cup feed or neglect to fill the oil cup promptly With this electrically driven screw-extractor a broken screw may be removed as quickly as a new one without waste of time. It is made similar to the portable electric drill e A triangle that can be used alone for drawing any kind of an angle or series of parallel lines di- rectly and easily A handle like a saw grip to receive the shank of an ordi- nary file of any size A light inclosed electric hoist that may . be operated from a distance and fall = % ; used in a manner ce 6 ass similar to the hoist- SS : ing unit on travel- WORK TO BE HELD IN PLACE » ing jib or wall cranes. ‘The addi- FULLY EXPANDED, ES . PRLY tion of an operator’s * rie cab adapts this A vise for use between milling hoist for high speed An expansion bolt shown machine centers which saves intercommunication in detail in Fig. 1 and fully much of the time of the usual set-up expanded in hole in Fig. 2 74 A hook made of strong wire with a snap having a tem- pered steel tongue at one end is very handy for holding a paint bucket or fruit pail on a ladder rung The usual method of cutting the larger sizes of pipe on a lathe is improved upon by the use of the hand power threader illustrated above. It may be taken to the job A portable electric. ally driven valve- grinder which gives the familiar oscilla- ting motion. | eS Se ee Sane Sone bone beer Zee vale By changing the form of the interior bore of this anchor for a screw the max- imum expansion is given where the greatest frictional contact occurs, which increases the holding capacity An ordinary electric ceiling fan is kept running in this vestibule and when the outer door is opened the air is driven outward so swiftly that very few flies, if any, will be able to effect an entrance 75 A measuring gage using a fluid against a flexible diaphragm to obtain readings in ten thousandths of. an inch or closer to determine the thickness of stock speeds of the elec- tric grinder are far greater than those 8 attained by the The hand mgthod Fighting in the Air The new machines that have been evolved and the way they fight four miles above the ground By Waldemar Kaempffert (The following article is based upon facts which have been kindly supplied by Major W. L. B. Rees of the British Commission. Major Rees was sent to this country as a member of the British Commission to give to our army officers the benefit of the British experiences on the battlefield with flying machines. He is an officer of the Royal Flying Corps who has seen active service in the air and who, single-handed, brought down ten German flyers.—Editor) ‘HE General Staff of every European army knew five years ago that the airplane would prove a potent factor in war. Germans, English, French, Ital- ians, all had tried to evolve a system of air- scouting in their annual maneuvers. The Italian campaign against the Turks in Tripoli and the Balkan wars had proved clearly enough that a man in the air could see more than could a man on horseback. And yet all the European generals entered this war without even a dim realiza- tion of the terrible demands that would be made of aircraft; of their utter dependence on a handful of dauntless men ready to vault into the air and brave not only the unseen whirlpools and maélstroms of a turbulent atmosphere, but bursting shells hurled from the ground and the machine- gun fire of an adroit enemy air-fighter; of the inadequacy of the airplane as it was . built before that fateful month of August, 1914, when all Europe was plunged into carnage; and of the frightful wastage of machines and lives. Even the Germans were unprepared. New Types Had to Be Evolved for the Exigencies of Battle Every army had machines—the French and Germans hundreds of them. But no one knew that airplanes would have to be built for very special military purposes; that the same machine could not be effect- ively used for scouting and fighting; that the acrobatic performances of Pégoud and his imitators in ‘“‘looping-the-loop’’ and diving tail-first would be elevated to the dignity of military tactics with which every fighting airman would have to be familiar. In two years the whole art of airplane con- struction has been almost miraculously improved, and the art of flying, too. Be- fore the war, some effort was made to adapt the machine to the man; now the man must adapt himself to the machine. Where are the elaborate, automatic stabiliz- ing devices with which all governments ‘carried by various machines, 76 experimented before the war? Where are the machines advocated for their inherent stability? The machine of 1917 is only out- wardly identical with the machine of 1913. About six types of machines have been developed as the result of war experience: 1. There is the fighter—a 150-mile-an- hour, single seater, which is armed with a machine gun; which has limited fuel- carrying capacity, and which serves to find, fight and destroy the enemy. 2. There is the two-seated fighter. It car- ries a fixed machine-gun at the front and a machine gun on an “‘all-around”’ mounting for the observer in the rear It is not so fast as the single-seated fighter. It also finds and fights the enemy; but it also escorts patrols into the enemy country and protects machines engaged in fire-control. It has more fuel-carrying capacity than the single-seat fighter, because it must stay up longer. 3. The reconnaissance machine is armed like the two-seated fighter; but it is not so fast and does not climb so rapidly. For short distances over the line it is amply able to protect itself. If it goes far, however, it must be protected by two-seated and even single-seated fighters. It is equipped with a built-in stereoscopic camera. The pictures taken are studied by staff officers to note changes in enemy positions and to discover concealments. 4. The fire-control machine directs the batteries by means of wireless. A recon- naissance machine when fitted with wireless apparatus may be used for fire-control. 5. The bomb-dropper resembles the two- seated fighter, although bombs can be Bomb- carriers, being weight-carriers, are large. 6. Night-flyers resemble either the recon- naissance machines or two-seated fighters. All Europe Was Aéronautically Unprepared —Even the Germans ' It was a very heterogenous collection of machines that took the air at the outbreak — oe Lom, Captain Georges Guy- nemer, pic- tured below, is probably the most skilful air-fighter on the French side. Although he joined the aviation corps a mere boy, he has been rapid- ly promoted. He hasarecord of thirty-seven German ma- chines to his credit. In the picture he is holding the battered, twisted rem- nant of a ma- chine gun taken from a German battle plane that he brought down Carrying the War into the Air x AY 20,000 FEET SQUADRONS OF FIGHTERS -— CIRCLE AROUND EACH OTHER 4 he ee cl fe GERMAN : ‘\ r i ww AT 10,000 FEET <2 LARGER TWO SEATED SCOUT _ MACHINES TAKE PHOTOGRAPHS = ee ay a 7 AT 6,000 FEET BFIRE CONTROL MACHINES WIRELESS. "BACK THE HITS AND MISSES HOW TWO FIGHTERS ATTACK A SINGLE ENEMY, CUT OFF FROM HIS SQUADRON x 2 J4 BRITISH a ae \ — te cies “aad f / The opposing squadrons watch and watch each other. Woe betide the man in a squad- ron who lags behind for a second, who man- ipulates his control a little too carelessly, who is not quite en rapport with his team- mate in the machine beside him! Two enemies swoop down upon him. He is cut off from his fellows. He must fight for his life. Up and down, in and out he maneuvers, shooting when he can. But his enemies out- number him. He has not a chance. There is a squirting of bullets. His machine drops— a sickening sight—three miles to earth 77 Cia p t:a in Boelcke, pic- tured below, was by far the best air fighter _ that Germany produced. He was killed at the Somme in a collision with a member of his own air- squadron. Boelcke was such an im- portant per- sonal factor that, although he had_ been sent home to rest by the Emperor, he was recalled when the Ger- mans found that they were losing in the air alarmingly at the Somme © Central News Photo Popular Science Monthly © Press Illus. Serv. Two extremes in airplane ce ads big bomb-carrier and the fast single-seated fighter. See key diagram below CIRCULAR TRACK — SHIFTING CANNO DIRECTIONAL. RUDDER HEAVY a aS ta ef 8 REAR FINS do "ii ‘ROW OF RELEASING / HOOKS FOR BOMBS AILERONS FUEL TANKS a sf ELEVATORS AUXILIARY REINFORC- ; ING STRUTS TO HELP FERESSlEe SUPPORT AILERONS LOWER PLAI SUPPORT WEIGHT BOMBS CABIN (OPEN ON TOP) wn CELLULOID WINDOW: 2-INCH CANNON WITH LONG RECOIL REINFORCEMENT ON TO OF AILERONS ONLY ON UPPER WI PNEUMATIC BUEFERS RADIATOR DIRECTIONAL RUDDE LSO WITHOUT FIN POR INSTANT MANEUVERING HIGH POWER ROTATING MOTUR} VERY LARGE ELEVATOR WITHOUT FINS FOR IN. PROPELLER STANT MANEUVERING LANDING GEAR IN DU- MORMING TRIANGLE AND DISPENSING WITH GREAT WEIGHT SOME WIRES of the war—monoplanes with tractor pro- pellers, biplanes with both tractor and pusher propellers, machines with and with- out streamline bodies, fast racers, and slow, cross-country flyers. One would suppose that the military brains of Europe would have foreseen that some effort would be made to beat off a prying airscout. That it was foreseen, the rather crude anti- aircraft artillery evolved before the war proves; but.no one could foresee how combats at a height of ten and twenty thousand feet would be fought, or how a machine should be designed for effective fighting. Maneuvers in time of peace may teach much, but blank cartridges can never teach as much as cold lead. First of all, it was discovered that for bombing raids, for reconnaissance and for fighting, different types of machines must be employed. Your bomb-carrier. cannot be much faster than ninety miles an hour —slow as speeds go nowadays. Such craft must be protected by fast fighting’*machines during a long over-land flight to some hostile railway junction which is to be wiped off the map. Your scout and artil- lery-fire control machine must stay aloft for hours; it must carry much fuel; there- fore, while it may be faster than a bomb- carrier, it cannot be designed for high speed. Slow machines must be protected from attack on overland journeys by fast fighters. And so the fighting machine was evolved —a marvelously swift machine, making as much as 130 miles an hour and as quick as a dragon-fly in darting and twisting about. Reconnaissance, artillery-control maz- chines, fighters—all are armed with ma- chine guns. But only the fighters, single and double seated, are built specifically for combat. The others fight only when they must—in some situation of dire necessity. How a Difficult Problem Was Solved There was no fighting in the air during the Tripolitan and Balkan campaigns; but in this war there was air fighting almost from the beginning. At first rifles and pistols were used. They proved worthless. A machine-gun alone could be used effec- tively, something that would squirt death like water from a hose. But the use of a machine carrying only one man. _ ply because they machine-gun implied the building of an airplane able to mount and fire it. _ it was soon found that the pusher type of Now airplane, which carries its propeller in the _ rear, is not so fast as the tractor, which carries its propeller in the front. It was also found that for fighting, at least, quick-maneuvering ability is highly essen- tial, which implies a small, high-powered Here was a very difficult technical problem to be solved: The fighting machine had to be a tractor for speed; the propeller in front necessarily interfered with the proper manipulation of the machine-gun; the officer in the pilot’s seat had not only to keep his machine on an even keel but also to fight his gun. Had the military strategists of Europe been told before the war that these were the conditions that _would have to be fulfilled, they would have dismissed them as absurdities at once. But by the middle of 1916, the requisites were so clearly recognized that they were met, and that with astonishing ingenuity. The Fast Fighting Machine Appears Popular Science Monthly 79 fifty horsepower and even more; and they - were strengthened so that they might withstand the enormous stresses set up in flight by engines so powerful. Curiously enough, the problem of firing through the propeller had been solved before the war by some imaginative in- ventor with more vision than is given to academically trained generals, and curi- ously enough it was solved in both France and Germany simultaneously. The solution was this: The gun was rigidly mounted in front of the pilot, and it was mechanically connected with the engine. A propeller revolves at about 1,200 revolutions, a minute; a machine-gun fires at the rate of 600 shots a minute. Let the engine fire the gun at just that fraction of a second when no propeller blade intervenes—that is the solution. Because the gun is rigidly mounted, the air fighter must turn the entire machine toward his German enemy to fire it. The enemy does the same; for the German Fokker, an adaptation of the French Morane-Saulnier, is similarly designed and equipped with a fixed machine-gun. ‘By the end When of 1915 it had these fighters been discov- first ap- ered that of. peared on the all the flying. side of the machines Allies they used by the Allies, the, fast racing monoplane of Morane- Saulnier in France and drove every- thing before them. It was impossible for the slower Germans to cope with the speedy them. Then biplane aa the Fokker racers made © Central News Bhote Service ; See key diagram below appeare d. by the two Fast fighting machines have engines of 150 horsepower and The ma: more, and are strengthened to withstand enormous stresses Z firms of Sop- chines of the with and Bristol TOP PLANE CUT OUT TO LIBERALLY PERFORATED LIGHT STRUTS REIN- Allies were PERMIT UPPER VIEW in England were best adapted for a PIN air fighting, sim- WITH WATER JACKET had speed and dragon-fly ma- br: neuvering abil- =Z ity. They were . given more speed by equip- ping them with engines of one hundred and ¥, p ~~ E AND VENTILATED HOUS= INGS FOR MOTOR STATIONARY MOTOR FORCED BY HEAVY WIR- ? ING TO THEIR CENTER madestill faster; the fighters be- came more skil- ful, more daring; fighting tactics were evolved. As a result, the Allies have not only caught up with each Ger- man improve- ment but have P surpassed it. 80 Popular Science Monthly Itis rarely that German machines—fighters or scouts—appear over the French and British lines; but the machines of the Allies are always over the German lines. That meant much at Arras. When these fast fighters first made their appearance there were some single-handed combats. A German and British charioteer of the air would wheel about, jockeying for a position in which, for a few fleeting seconds, either might pour in a hundred bullets at his enemy. It was a favorite maneuver of the German flyer to rise very high, to plunge down on an adversary, and to fire as he came. But Boelcke and Im- melmann were about the only flyers on the German side who were either skilful or daring enough to engage in frequent single- handed combats. As a rule, the Germans attacked a single British or French machine - in twos and threes. The procedure may be attributed in part to the different tempera- ments of Germans and British and in part to military policy. Like Flocks of Birds the Squadrons Maneuver The result has been that fighting in the air is now undertaken, as a rule, only by ‘squadrons. Six machines, sometimes more, constitute an aerial tactical unit. Their pilot-officers live together, sleep together, eat together. They know one another better than if they were brothers. Every mental and emotional - characteristic is bared. So it happens that in the air, when the six machines are flying side by side in twos, the men know instinctively what they are to do. Have you not seen flocks of birds on the wing, circling about with a unanimity of understanding that makes it seem as if they were obeying a command? It is so with the air fighters of a squadron. They move as one, like a flock of birds, with never a word of instruction. An engagement between opposing squad- rons in the air is not like a battle at sea— a fight between fleets. Around and around each other the planes whirr, each team following the leaders with clock-like pre- cision and automaticity. The opposing squadrons watch and watch each other. Woe betide the man who lags behind for a second, who manipulates his controls a little too carelessly; who is not quite en rapport with the team-mate in the machine beside him! Two machines of the enemy swoop down. He is cut off from his fellows, like a bird from its flock. He maneuver two machines. must fight now for his life. Up and down, in and out, he maneuvers with his foes. He shoots when he can—when a hostile ma- chine is directly in front of him. But his enemies outnumber him. He cannot out- One, at least, must sooner or later swing around into a favorable position. Then there is a squirt- ing of bullets. The machine drops, a mass of flame, three miles to the earth—a sicken- ing sight even to those who have been steeled to the horrors of the most horrible of wars. A charred, twisted mass of metal and wood is picked up. Within it is a. scorched, torn uniform containing an un- recognizable, mutilated mass, all that re- mains of a brave man who was not quite quick enough, or whose mechanism failed him for a fatal fraction of a second. How the Airplanes Carry War Into the Atmosphere Whenever that terrible artillery prepara- tion takes place of which we read in the newspapers (the deadly hail of,tons and tons of metal that precedes an attack with the bayonet) the fighting squadrons are high in the air—twenty thousand feet above the ground. Below them, at perhaps ten thou- sand feet, are the two-seated fighters and reconnaissance machines each patrolling a section of the enemy’s line, taking hundreds of photographs. And below, at six thou- and feet, are the machines that control the artillery fire—machines that watch each shot as it falls and that wireless back the signal “‘too short’’ or “*‘too long.” Without the reconnaissance officers the scouts and the fire-controllers could not perform their task; they would be attacked and annihilated by fast airplanes mounting machine-guns. To be sure, they are armed themselves so that they can keep up a running fight. But on the daring, fighting squadrons far, far above the battle line, on them depends the fate of an army; on them depends the possibility of gathering the facts that the heavy artillery in the rear must have to fire at a mark ten miles distant. To the all-seeing eye in the air, nothing is concealed. It is that eye which has made it utterly impossible for either side to execute a flanking movement that would envelop a whole army and compel a sur- render, that eye which has made it necessary for armies to burrow in the ground and face each other in a nerve-racking, soul- trying struggle. Popular Science Monthly 81 A garden in which aa ree but weeds can find a place. where weeding means cultivation of weeds. A Garden in Which Weeds Are Not Only Tolerated but Cultivated OR every evil under the sun there is a remedy or there is none,’’ says the jingling rhymster, and leaves it to the scientist to find out whether there is or not. To find the remedy for weeds, the bugbear of every farmer and lover of growing things, a garden was planted at the Agricultural Experiment Station of the University of _Minnesota and 175 different varieties of the pests were given honorable lodg- ment in the perfectly good soil. They grew. They thrived. They bore abun- dant seed. They were classified and a collec- tion of weed -seeds was produced and listed. Then repel- lents and ex- terminators -If he becomes hum-drum, It is the one spot in all the world, perhaps, Later on, various exterminators will be tried on them Taking Motion Pictures on the Road in a Queer Vehicle HE motion picture director is a creature of weird fancies. If he were otherwise he would not be a motion picture director. He lies awake nights worrying about ways for, doing something different. if his ideas smack of the commonplace, his directorship is soon ended. The quest for novelty partly explains the freakish caravan on’ rubber tires which the accom- panying photograph shows. The pur- pose of the queer equipage is serious. It is seeking the right landscape for a_back- ground for a special com- edy, and is transporting the camera were tried out on them. Film comedy has its queer moments, such as traveling in freak equipages and make-up in search of suitable landscape and troop to the spot. Chasing Submarines with Motor-Boats ~ By Prescott Lecky HEN England found the submarine was a menace that threatened to destroy her paramount position asa maritime power and a maritime nation she cast about her for a means of combating the underwater terror. One of her purchas- ing agents visited the New York office of Henry R.Sutphen, an official of a boat-build- ing company and a submarine company. “Why don’t you try motor-boats ?”’ sug- gested Mr. Sutphen, and proceeded to out- line the sort of craft he had in mind. The conversation resulted in a provisional order for fifty boats, given subject to the approval of the British Admiralty. Not only was this order confirmed, but a short time afterwards it was increased to five hundred and fifty. The boat called for was to be 80 ft. long, 1214 ft. beam, 4) ft. draft and of 32 tons displacement. Two standard motors of 220 horsepower were to drive her at a speed of fourteen knots for 850 nautical miles or nineteen knots for a distance of 700 nautical miles: ‘The fuel capacity was to be 2100 gallons, and the gasoline was to be con- sumed at the rate of one pint per horse- power perhour. She was to carry a crew of ten men, including gunners to operate the 3-inch rifle mounted forward. Applying Automobile Manufacturing Methods Naturally it would have been impossible to construct so many boats of such a large After the boats are assembled in the sheds they are launched directly into the St. Lawrence River = 82 Boats for the purpose are built up in sections produced in immense quantities, like the parts of the low- priced, easily assembled automobile size in so short a time by the usual methods. The methods of the automobile factory — were adapted to the shipyard. First, “the: master boat’’ was built and every part that . went into its construction was carefully measured and recorded on templates or wooden patterns. The templates were then sent to the shops and five hundred duplicate pieces ordered. Every one of these pieces was lettered and numbered on its arrival at the plant. Three machine shops were kept busy turning out the motors. Most of the woodwork was done in Bayonne, N. J. More than eight and a half million feet of finished lumber, sawed and dressed to the required sizes, was turned out by this shop. When arrangements had been made — the material, new yards on the St. Lawrence River in Canada were about completed. The plant consisted merely of half a dozen huge assembling sheds, and it was here that most of the ships were made. As the keels arrived they were put in their places along the floor, and the delivery of the various ribs, beams and parts was so timed that no storage space was necessary. Every effort:was made to simplify operations and to avoid handling and carting the material more than once. For instance, as soon as the engine, anchors and chains arrived they were distributed immediately, an anchor being apa in front of each keel. Popular Science Monthly 83 All told about fifty separate operations were necessary in putting these parts together; for each task there was a separate gang of workmen who did nothing else. It was not advisable to build a permanent plant of this size equipped with cables and roof pulleys. Hence progres- sive assembling in the automo- bile sense could not be applied. Automobile- assembling practice was re- versed. The boats remained stationary while the men moved along. Otherwise there was no essential diff- _ four chasers being carried on one liner. Since the war began, the production has increased from three boats a year to three a day. Five hundred and fifty submarine chasers, eighty feet in length, were com- pleted in less than five hundred and fifty days from the time the con- tract was signed. Perhaps the most surprised wit- ness of this accom- plishment was the British Admiralty itself. And Eng- land, as every- one knows, is the greatest maritime na- tion of the world. An idea of the tremen- dous amount of detail that aio erence. So rap- idly were the boats com- pleted by this method that the sheds were soon crowded, and extra keels were laid outside. Some of the boats were launched directly from the shed while others were placed on railroad trucks and carried to the ways. Every vessel was thoroughly tested by British Naval inspectors before it was accepted. The. boats were shipped to England on the decks of ocean steamers, Some of the chasers were launched from the shed but others were made inshore and had to be brought to the ways by rail had to be looked after in this under- taking may be gained from the following brief list of figures: 550 gas stoves, 2,200 fire extinguishers, 2,200 sailing lights, 550 life boats, 550 searchlights, 25,000 incandes- cent lamps, 974,504 bolts and nuts, 3,850 oil lamps, 13,200 canvas covers, 22,000 storage batteries, 109,450 ft. of brass pipe, 611,000 ft.of manila rope, 33,200 running yards of deck canvas, 16,500 port lights, 1,650 sinks When the sheds in which the boats were assembled were filled, additional keels were set ‘up outside. Here some of the boats are shown in an advanced stage, almost rgady for launching “84 Popular Science Monthly Some of the finished boats ready for inspection. Picture continued on next page Each boat was thoroughly tested in the St. Lawrence River before being accepted. Arranged as in the photograph the five hundred and fifty boats and wash basins, 11,550 ventilator cowls, 1,650 toilets, 325,000 ft. of wire rope of various kinds and 450,000 pounds of paint, varnish and putty. Will Every Coast Dweller Own a Motor-Boat? In the assembling operation alone more than 3,000 men were employed, and about 9,000 others were scattered in the various workshops fabricating the material before it was sent to the main plant. This is the first time that the principles of standardiza- tion, division of labor, and progressive age citizen as is the popular-priced car. The movement toward standardization began in 1905, when Mr. Sutphen’s com- pany built 120 twenty-one-foot mine-yawls for the United States War Department. The same company two years later built 33 thirty-foot mine layers on standard lines, and during the next six years turned out 110 thirty-six foot power life boats for the United States life-saving service. Probably the largest motor-boats ever built according to uniform design were two 98-foot yachts, made in 1910. Others who have made experiments along the same line assembling have ever been applied with any thoroughness to shipbuild- ing. There is no reason, however, as this success- ful experi- ment proves, why motor- boats cannot be turned out cheaply enough to make them areacompany that turned out a number of thirty- footers, and another that has been building twenty - foot steel motor- boats in fairly large quanti- ties on stan- dard pat- terns. It should not be imagin- ed that these as available to the aver- a separate gang of men. About fifty operations were involved, each requiring Here’is' the ‘ribbing gang” submarine chasers built Popular Science Monthly 85 covered eight miles. End to end they would form a chain nearly twenty-five miles long for England were motor-boats in the ordinary sense. They were really yachts. The interior design from bow to stern was as follows: Chain locker, lavatory for crew, forecastle for eight men, am- munition room, large fuel tanks, engine room, gal- ley, mess room, office state room for two and additional tank capacity in the ex- treme rear. On deck there was a platform forward for a three-inch gun. Behind this was the chart house, and further back still the bridge where the steering apparatus and engine telegraph were located. One feature of this boat is an arrange- ment by which the steering lines are laid along the side of the deck from the wheel, making them easily accessible forrepairs. Channel and the North Sea, and while their sea-keeping qualities are excellent, never- theless they do not carry enough food and fuel to last more than ten days. On the other hand, however, a boat of this size painted gray is invisible at a distance of more than three miles, so that it is often possible to catch the submersible unawares. The boats are intended for offensive opera- tions almost entirely, though of course they would make good convoys near the coast. The British have discovered that fighting the submarines is a question first of all of endurance. A larger chaser would be more comfortable, of course, but by no means so dangerous to the submarine. A Board Which Will Help You Learn to Swim SWIMMING board invented by William H. Roberts, of Newburyport, Massachusetts, is a help in learning how to swim. The device is nothing more than two warp-proof boards of pine which are fastened together at a very large angle. The swimmer straddles these at the narrow junction of the boards. Lying with his body flat upon the front board and resting more or less upon the saddle board, he is buoyed up in the natural position for swimming. He learns the leg strokes first and then the arm strokes, and he rests back upon the boards whenever he becomes tired. By keeping his legs going slightly, the board is kept from overturning. The buoyancy of the boards helps him to ride the waves and contrib- utes to his enjoy- ment. Since there is no danger to fear, confidence is soon gained and the swimming strokes are mastered in short order. The The chasers were designed for service in the English The buoyancy of the boards prevents you from sinking below shoulder level swimming board is used purely for sport, also. , 86 ene Science Monthly the operator then presses another button to return the money to the caller, just as in other pay-telephone systems. ~This accessory has a credit fea- ture, however, which is unusual. In case the tenant is out of change, the operator releases a brass check of the size of a nickel from the coin box. The tenant uses this, and when the manager comes around to collect the coins deposited, the tenant redeems these from him. Be Thou Wary of the Bubbling Cup telephone. Changing the Apartment Telephone into a Pay-When-You-Call System NEW telephone device deserves a Carnegie medal for furthering the cause of universal peace between tenants and apartment house managers. It enables the manager to collect at the time of the calling, and protects him and the tenant as well from being over- charged. The coin-collecting device works entirely independently of the regu- lar telephone system. Thus, the tenant calls the operator’s switchboard in the apartment house lobby and is connected with central just as_ usual. But before the operator ac- tually connects the tenant with central, she connects the coin- collecting box in the tenant’s apart- ment with a recording box on her switchboard prefacing the action with a request for “Five cents, please.” The recording box signals her the instant the nickel is placed in the collecting box. If central obtains the person called, the opera- tor then connects him with the tenant, and by pressing a button, deposits the nickel in the coin box. If the person called cannot be found, The tenant depos- its a coin in a slot just as in a public This is carried to the coin box when the con- nection is made GERMS HELD UP BY JET OF DRINKING CUP The principle in accordance with which the ball is held up in the of water is the same as that of the germs held in the bubbling fountain PROFESSOR in a_ western university has discovered that small organisms lodge in a great many kinds of bubbling-cup drink- ing fountains, and for a curious reason based on an ancient physical principle. Twenty-five years ago writers of textbooks on physics had not the wealth of material to draw from that is now available. In carrying out one of their few experiments a rubber-tube-and- spout arrangement was prepared in such a way that it could be attached to an ordinary water faucet and a small jet of water was projected directly upward. In this jet a small ball-would be placed— and, curiously enough, would remain in the air, almost stationary, held up by the jet. The jet seemed to clutch the ball and hang onto it instead of throwing it away. The stream would divide under the ball, come up equally on all sides and hold it in place. The . sphere might oscillate up and down slightly, but otherwise it appeared to be settled per- manently in place. The western ee professor men- \ tioned has dis- | covered that. ba- cilli may oscillate up and down in ' some kinds of bubbling cups all day long, day after day—in the same way and for the same reason that the sphere did:in oes the old-time jet. aS jet Popular Science Monthly 87 Ez \3 FREIGHT xe BROWNS RESIDENCE PORCH 34'X8' BUILT FREIGHT CAR KITCHEN ped 34'4° x8 BUILT ON ROOH, 8x8 DINING ROOM fate a 344°K 344 FREIGHT FREIGHT CAR CAR, 344 34-4 xe x8 ILT IN FRONT a | FRONT PORCH 50°x8 ONE LARGE OUTSIDE WINDOW FOR EACH ROOM Plan and finished appearance of the box-car hotel. There are eight guest rooms and the land- lord’s apartment, besides hotel kitchen and storeroom. The two-story effect is only simulated Owens Valley, California, Has a _ Freight-Car Hotel WENYO is a railroad junction point in Owens Valley, California, east of the Sierra Nevada Mountains. Mining and agricultural development have made it important. But it had no hotel. George Brown built one with the best material that he could find. He couldn’t get steel for a frame or onyx for a foyer, but he could get box cars. So he built his hotel of box cars. Standard box cars are thirty-four feet fourinches long, eight feet wide and eight high. Three of these, unwheeled and with proper foundation, were placed in the form of a hollow square, inner corners connecting, with the open space facing the tracks. In this open- ing a front was built, | with double doors and large windows. The center is a din- ing-room thirty-four feet four inches square, well floored, and lighted by many windows in a superstructure which gives the appearance of a second story. Across the front is a fifty-foot porch eight feet wide and across the rear another. Behind that is a fourth car, constituting the residence of the landlord and his family. Each of the side cars is divided into three comfortable bedrooms, and at the rear, on either side, another guest room is built in, Adjustable supporting trame e ( Ata a - \ Spring clarm i © A float on the rising water lifts a lever which operates the alarm mechanism making eight guest roomsinall. The rear car in the building is the kitchen. The entire building is metal-roofed, plaster-board finished and paneled through- out the interior. Every room has a large window. Turn on the Water in Your Bath. It Can’t Overflow. This Alarm Wiil Warn You in Time ILLIAM J. ABERLE, of St. Paul, Minnesota, has devised an alarm which tells you when your bathtub has been filled to whatever depth you de- sire. Instead of having to watch the rising water, you simply ad- just the alarm and let it do the rest. A light hollow float is suspended in the water by a verti- cal iron rod. The rising water raises the float nearer and nearer to a horizontal lever con- nected with a bell. When the rod rises high enough its upper end touches the bell trigger. A spring is immediate- ly released by the trigger, a clapper is brought into action and the bell rings. By adjusting the height of the bell mechanism, the height to which the water must rise to sound the alarm can be regulated as desired, . A Ten-Ton Motor-Truck on Eight Wheels It combines the greatest possible carrying capacity with the high speed and easy riding of lighter trucks The eight-wheel truck is mounted on two sets of four wheels each, with tires of the pneumatic type. accompanying illustrations is mount- ed on two trucks, patterned after the old-fashioned four-wheeled railway coach truck, having eight supporting wheels in all. Each wheel helps to drive the: vehicle, which is thus always able to secure traction, since it is extremely unlikely that all eight wheels would be mired at once. Because of the large number of support- ing wheels, the tires may be of the pneu- matic type, even for as large a vehicle as a ten-tonner. The use of such tires instead of the solid-rubber type, which must now be fitted on the conventional ten-ton vehicle, would cushion the driving mechan- ism to such a great extent that the vehicle could be run with safety at greatly in- creased speeds. This is in line with the most advanced trend in vehicular trans- portation, which is to carry as large unit loads as possible at the greatest speed compatible with safety. Large loads on one vehicle take the place of smaller loads on a larger number. of vehicles of less capacity. This substitution means less traffic congestion, which is one of the greatest problems the police forces of our é he novel motor vehicle shown in the This arrangement provides an easy-riding vehicle of great stability and carrying capacity most important cities have to contend with. Aside from the advantages of carrying large loads at fast rates of speeds on pneumatic tires and of being able to secure the necessary driving traction at all times, even on bad roads, the eight-wheel ar- rangement also provides an extremely easy-riding vehicle of great stability and one of extremely short turning radius, since in the case of the vehicle shown, all the wheels are mounted so as to turn for steering. . ; In detail, the vehicle is mounted on two -sets of four wheels, each set carried on a 88 suitable cross-frame member. Each cross member has two arms on each end. Each end is made into the shape of a yoke to carry a wheel on a vertical spindle. This spindle simply serves to support the wheel so that it carries its share of the vehicle load and so that it can be turned in steering. The power for revolving the wheels is secured from a conventional gasoline motor placed off the center line of the vehicle to the right at the front. The motor shaft extends aft of the crankcase in the usual manner and transmits its power to a four- speed gearbox located between the front and rear sets of wheels by means of a short driveshaft. The power is in turn trans- mitted through the gearbox by means of a silent chain drive to two shafts, one extend- ing forward from the front of the gearbox and the other aft from the rear side. Each of these shafts carries two worm gears, these meshing withlargeworm Sa: i. ape ano AXLE eH CROSS Popular Science Monthly PNEUMATIC TIRES The STEERING RODS JN 89 the center. The separate lever serves to turn the vertical turn-bolt as the driver turns his hand-wheel to steer. Additional rods attached to one end of the two-armed bar lead to the front set of wheels, and other rods attached to the opposite end lead to each op- UNIVERSAL JOINTS posite pair of # Co) the rear wheels. AA | Thus as the i turn-bolt is re- wheels and dif- wy) ferentials $$ ———— WORM GEARS. volved, causing the two-armed ipal mea i Se. a _ i -—— "! if x Ny mounted on or a sl wi mS SS bar to revolve supplementary | GEARSET/ ors about its pivot, ‘axles which , || li it makes the simply drive @—“—)[- wae Le front truck each pair of op- ~ SPINDLE ARMS — EXTENDED MOTOR SHAFT “ae merase Centre Wheels turn in posite wheels, but do not sup- port any of the wheel load. Each of the supplementary driving axles is divided into two parts on each side, these parts being joined by means of universal joints so as to permit relative motion between any of the wheels of each truck, as when passing over road obstruc- tions, without binding any of the driving members. The motor must be placed rather high so as to clear'the front axle of the front truck. The top of the motor extends up into the driver’s cab and is covered by aremovable metal hood. The driver sits on one side of the motor and the helper on the other. This construction permits the driver’sseat to be placed well forward, which in turn allows a longer body on the same length of chassis than would be the case in the usual construction with the motor under a hood out in front. All of the wheels are arranged to turn for steer- ing, this being accomplished through one steering wheel and column by attaching the steering crank by means of a rod to a vertical turn-bolt carrying three arms. One of these arms is a separate lever, while the other two really comprise one bar pivoted at Diagram showing the driving and steering arrangement of the eight-wheel truck. All wheels turn for steering The outer wheel presses against the edge of the path to insure a straight line. A trough is dug at the same time one direction and the rear wheels, con- trolled from the opposite end, in the re- verse direction, thus giving a very short turning radius. To Make Your Lawn Attractive You Must Edge It Evenly N improvement on the ordinary lawn edger has been invented by Christian L. Schneider, of Davenport, Ia. It not only edges the lawn neatly but cuts a trough at the same time at a regulated depth. The edger consists of a J-shaped knife carried on an arm which ad- justs it to any height. One of the wheels of the edger runs on the path surrounding the lawn, with its outer flange pressed against the asphalt so as to insure a straight line. The other wheel is ar- ranged so that it will keep parallel with the wheel on the path, whatever irregularities may occur in the lawn over which it travels. This makes it easy to push and insures a straight edge. ADJUSTABLE KNIFE 90 An Adjustable Rake for the ‘“‘Land Patriots’’ LL contributions to the cause of agri- cultural preparedness will be gratefully re- ceived! Especially when they are as good as the adjustable garden rake that is shown in the accompanying illustra- tions. Instead of hav- ing to use a number of different sized rakes to fit between rows of diff- erent kindsof vegetables, you can adjust this one rake to suit all purposes. All the teeth of the rake, excepting the central ‘one, are riveted to two rectangular side-frames pivoted to an iron socket on the end of the rake handle. When weeding, Above: The side teeth adjusted to a narrow row. At right: The rake opened out or when loosening the ground between rows of potatoes, for instance, the side bars are swung around until they aline. thus opened to its fullest width, is then locked in this position by the wing nuts When cultivating onions, on the other hand, the angle between : the side bars can be reduced to adjust the rake to the smaller shown. width. When the sprouts are young, this rake can be used for cultivating both sides of the row at one time. Thecentral tooth may be unscrewed and taken out making it possible for the rake to operate on both sides of the small shoots. Popular Science Monthly When the central tooth is re- moved the rake will straddle the small shoots. Then both sidés of the row can be worked at one time The rake, wire Supporting Frame The cheese-cloth strainer extends back into the barrel like a long, hollow tube Eliminating the Noise from Railroad Traveling NE railroad at least has solved the noise problem. Much to the delight of the passengers, the “Bur- lington Route” has rooted out the grinding of wheels, the creaking of axles, and the other noises usually attendant upon traveling. They have accomplished this by installing a sound-. proof flooring in their new steel cars. A layer of hair felt one inch thick, a layer of spec- ially prepared paper, and a half-inch air space separate the steel floor of the car from the steel sub-floor nearer the ground. The sounds coming from the wheels are practically all ab- sorbed by the insulating layers. Especially in traversing the loosely packed felt, the sound vibrations are readily lost in the loosely connected fibers, so that they will never reach the ears of the travelers. Combining a Strainer with the Bung of a Barrel BARREL attachment which serves as a bung and a strainer in one has been devised by William R. Brison, of Tompkinsville, New York. Screw the at- tachment into the barrel and contents can be drawn through an exceptionally fine | strainer, without re- tarding. the flow. The attachment consists of a’ hollow steel head that sup- ports the cheese-cloth covered wire frame- work of the strainer. a 4 Popular Science Monthly Counting the Moisture Drops in a Fog EASUREMENTS of fog have hitherto been crude. But an example of more re- fined measurements of fog has - recently been afforded by experts of the United States Bureau of Standards. The measurements were made in the most notorious- ly foggy region of the world—the Grand Banks of Newfoundland. The tiny drops that constitute a fog are smaller than raindrops. They are formed by the conden- sation of the gaseous water in the air, known as water vapor. Each drop condenses about a ‘‘nucleus’’ —consisting of some substance other than water. The air always contains an immense number of these nuclei, ready to form centers of condensa-, tion, when the conditions of temperature and moisture are right for this process. A method of counting these invisible nuclei was devised by John Aitken. It consists in causing a drop to form around each nucleus in a sample of air, and then counting the drops through a microscope. _ Another process, devised by Carl Barus, makes it possible to determine the size of the drops. When a light is viewed through a cloud or fog it is seen to be surrounded by a colored ring, called a “corona.” You have seen such rings around the moon and around street lamps at. night. -The angular di- ameter, or aperture, of these rings depends up- on the size of the ‘drops. Small drops produce big rings, and vice versa. The apparatus of Ba- rus was installed in the pilot-house of the Seneca, and the number of nuclei present in a given volume of air was measured three times a day, whether. the weather was foggy or otherwise. A sample of air was drawn through a pipe, projecting from the port bow. It was admitted to a “‘fog chamber,” saturated with water vapor, suddenly expanded, to con- dense water on the nuclei, . billion Martha’s combination umbrella and rain-cape. dog can crawl under cover Instrument for measuring the tiny drops of fog. Sixty drops equal one-seventh of a glass of water forming an artificial fog. The corona around a source of light, viewed through this fog, was measured, and the size of the drops was determined from the known amount of moisture in the chamber. | A Twelve-Year-Old Girl’s Combina- tion Umbrella and Rain-Cape LITTLE girl, Miss Martha Bachman, who lives in Chattanooga, Tenn., has evidently suffered the discomfort of ~ wet stockings caused by the flapping of her just-so-long rain-cape against her legs on her way to school, as so many other little girls have done in days gone by. But Martha hasan idea for eliminating such discomfort from future rainy days. Her idea is to attach a cape of oil-cloth or rubberized material to the rim of the umbrella with snap-fasteners, but- toning it down the front in ordinary rain-cape fash- ion. An isinglass window at about the level of the eyes would prevent the wearers of such an umbrella-cape from bumping into each other on the street, like pilotless ships. In this way books could be protected from the rain also and the hand holdipg the umbrella. Even the Can the Railway Train Be Made Noiseleaa? “Yes,” say the inventors, ‘“‘by improving the wheels.” “No,” say the engineers, ‘‘unless you perfect the road-beds” By Marius C. Krarup FLEXIBLE PAD The Maginn wheel is built up in sections secured together by bolts or rivets for flexibility Se idea of producing a noiseless rail wheel, and even making it distinct- ly: flexible to reduce the wear and tear of the roll- ing stock has seemed a good one to some in- ventive minds, and they have proceeded to patent their con- ceptions. These are all char- acterized by a noise-deadening ~ and more or less elastic sub- stance which isinserted between the flanged rim and the hub portion of the wheel; by some provision to prevent the rim from slipping round on the inserted material, and by guide plates on the sides to hold the hub and rim in aline- ment. The details can be followed without difficulty in the accompanying illustrations but are subordinate in interest to..the question whether the whole plan is practicable. It is next to impossible to make the ‘‘built-up”’ wheel as cheap or as strong as the one- piece construction. It is almost hope- _less to try to introduce a wheel which is after all only a little less noisy than those in use, unless it pays for itself from the start through savings in other directions. If the wheel is frankly intended to be flexible, as the Maginn wheel among those illustrated, it is well to remember that flexibility makes a constant demand on the power of the locomotive. In the Kinsman wheel the main object of inserting a non- metallic substance is to insulate the wheel and the car from the rail elec- trically, this being a requirement in some forms of electric railway service, and this represents a new angle of the subject having little to do with the other efforts. The Lindblad wheel, on the other hand, is a cushioned and anti- noise wheel with special wiring to pre- vent it from becoming non-conductive. The most radical and effi- cient method for securing comparatively noiseless op- eration as well as saving of road-bed and rolling stock, according to modern traffic engineers, comprises thor- ough grading, draining and ballasting of the road-bed, smooth hard rails of ample dimensions, manganese steel rails at crossings, frogs and improved design of switches, accurately con- isutatio’ Centric wheels and car springs with well damped and governed -rebound. l M At left above, the Lindblad wheel; These would reduce noise at right above, the Kinsman wheel and improve the service. The Madden sound-deadening wheel also has a flexible pad which fits like a lining around its rim 92 is an advantage The head and body of the suit are of cast metal riveted. The arms and legs, however, are of can- vas reénforced by coils of strong metal tubing. Flexibility is thus given them while. their ability to protect the limbs from being crushed by the enormous pressure of the wa- ter is not impaired The heavily laden divers are lowered by single steel cables which enclose the telephone wires through which the orders are trans- mitted. Oxygen apparatus is at- tached to each suit. In this enough oxy- gen is stored to last for eight hours. The weight of the. suit Salvaging in Armor S a diver goes down, the water pressure in- creases at the enormous rate of over three tons a square foot for every one hundred feet. This water pressure is overcome by supply- ing the diver’s lungs with air of an equal pressure. Evidently, the air pressure has to be increased the farther down the diver goes; but if at any time this pressure becomes either more or less than the water outside, the diver will be injured or even killed. This danger is entirely done away with by the armored diving suit invented by B. F. Levitt, of Toledo, Ohio. His suit entirely separates and protects the diver from the water. Manganese 93 94 Popular Science Monthly bronze, which is as strong as steel but not so likely to rust, has enabled the inventor to descend to one hundred and twenty feet below the depth attained in the former world’s record of three hundred and sixty- one feet. The great strength of this bronze “was found capable of withstanding a crushing pressure of some eleven tons per square foot. In marked contrast to the ex- perience of the three divers who made the former world’s record—one died shortly after—Levitt experienced no _ hardships whatever. The air was supplied from an oxygen apparatus attached directly to the back of the diving suit. The body and the head-piece of Levitt’s suit are of cast metal and are riveted together. The legs and arms, however, are of canvas so that they can be bent while the diver is working. These are prevented from collapsing under the water pressure by closely wound coils of strong bronze tubing. The water-tight joints at the shoulders, ankles and wrists run in ball-bearings so the pressure cannot cause them to jam. Obviously, the suit must be very heavy. This fact is by no means a drawback, how- ever, since every bit of the armor’s weight is required to make the suit sink down straight. After the suit has been assembled on the diver, he is lowered into the water by a steel cable unwinding from a derrick on the salvaging boat. This cable also serves the purpose of hauling the diver up after- wards. Small telephone wires form the core of the cable and connect the telephone apparatus strapped to the diver’s head with similar apparatus on the salvaging barge. Powerful electric lights and carriers for the loads are lowered with the diving corps. This method will be used in an attempt to salvage the Pewabic, which went down in Lake Huron nearly fifty years ago. Dummy Guns and Turrets Train England’s Gunners for the Sea HEN England trains her gunners for the sea, she sends them to Whale Island in Portsmouth Harbor. Here the entire island is given over to steel sheds which are built like gun turrets on a battle- ship. The great guns projecting from these sheds are dummies, though they are exact counterparts of those on a battleship. The prospective officers and men are made to go through the exercise of range-finding, loading, aiming and “‘firing’’ these guns as rigidly as if they were in a real battle at sea. The heavy steel projectiles are hauled from the magazine by hydraulic and electric cranes just as in an actual ship. A real breech mechanism locks the projectile and its powder charge in the gun while an intricate swivel mounting of steel swings the gun into the firing position. The great guns projecting from these sheds are dummies, though they are the exact counterparts of those on a battleship and can be loaded, aimed and “fired” by the recruits in training fe 5 4 a recent inven- tion of William Wilson, of New- z ark, New Jersey. ; L 7 r There is nothing éxceptional about the straw. The top of the hat, however, can be turned inside out. The folded water- proof covering ‘that is thus ex- posed can be drawn over the entire upper sur- face of the hat. Ordinarily the | Popular Science Monthly The Straw Hat for Storms. Top Turns Inside Out STRAW hat which can be taken out _ in the fiercest storm with uppunity is The 95 Arthur Picard, a resident of New York city. It is in three sections—a handle, a sliding support for the pad, and the pad itself which may be of bristles or of ab- sorbent material. The sliding support has side jaws which When it rains, the top of the hat is swung around and the elastic covering carried underneath the lid is drawn down over the entire hat waterproof cover is concealed beneath a cloth lining under the top. An elastic band keeps the lining drawn up tight. A Toothbrush for the Sick—It Has a Removable Pad ‘HE toothbrush of an ‘should be destroyed after a That is the practice in the more carefully conducted hospi- Ordinarily this would necessi- single use. tals. The pad may be made of bristles or of absorbent ma- » terial. Itis ex- | pelled from the groove and im- ._j mediately destroyed invalid clamp the pad securely in place when the ring. shown on the tapered portion of the handle is pushed up as far as it will go on the pi acdc holder. To re- lease the pad, the ring is slipped down on the handle, and the tongue in the groove of the pad-support is pushed up. This expels the pad from the groove. Protective Za) material if _ folded on # underside Lid turns on pivot pee Dad ene The Private Hairbrush—The Bristles Can Be Locked Up PPARENTLY only one man of inventive genius in all the United States has been able to remain unaffected by the zip-boom-bang of guns and war news and to ap- ply his talent to the cry- ing needs of everyday and home. He has invented a device for locking up his hairbrush to protect it from the other boarders in the house! It isin the form of a cover tacked to the back of the brush and with overlapping sides which fasten with lock and key. of brushes if the patient’s teeth are to be. properly cared for. tate having on hand a goodly supply Position of covering wlecoas brush isi in N Use .. With the type of brush shown in the illustration, however, only the pad, or bristles, need be destroyed. The handle may be sterilized and used as long as it lasts. The brush is the invention of Alphonse ina a Lock Flexible brush covering The cover is tacked to the back of the brush. ‘The sides fold over and are fastened, with lock and key 96 Popular Science M onthly The coat is fastened together in sections so that it pulls apart readily when caught A Safety Coat for Workmen. It Pulls Apart in Sections WO million machineshop workers in the United States read safety bulletins each week and operate machinery equipped with every kind of safety appliance which money will buy. Yet not a week goes by but several careless workmen are _ in- jured and one or two killed outright be- cause of their own reck- lessness. One of the most common forms of acci- dents is the catching of loose and exposed gar- ments in revolving shafts, pulleys and other moving machinery. Only recently a man wearing a ragged. sleeve while turning a bolt on a machine. in an Omaha shop was stripped to his waist. By a miracle his life was saved. Had he worn the safety garment illustrated on this page If the low-sunken propeller-hits a rock it swings up on its tilting “attachment and-clears the ob- struction in safety he would have lost part of the coat only. Herbert P. Andrews, of Portland, Oregon, the inventor, has designed the coat in sec- tions in such a way that any unusual pull on any particular section will detach it bodily from the rest of the garment.: The coat is not sewed ‘together at: the seams, but is fastened, one section to the other, by snap fasteners. Thus any section may be detached without tearing the rest of the garment or endangering. the life of the wearer. If the workman is fortunate enough to see the machinery catch his coat, he can pull himself away instantly, losing only one section of the coat.. The snap hooks and fasteners do not detract from the general appearance of the coat; and it meets all the demands for ordinary wear. Motor Attachment Which Prevents Injury to Rowboat Screw ITH the marketing by a Western con- cern of a tilting motor attachment, the motor-driven rowboat comes into its own. In the past when beaching the boats or when passing through shallow water, the propellers of rowboats using motor power were endangered. In a boat of such light draft as the rowboat, the propellers have to be held below the bottom of the boat to afford it sufficient ‘“‘push.”’ This, of course, is unsafe; for in beaching the boat, or in passing a rock or a snag in shallow water, the propellers are likely to be snapped off or bent out of alinement. The tilting motor attachment prevents such an accident. The entire propelling ap- paratus is mounted on the flexible tilting attach- ment, so that if anything strikes against the back of the propeller the ap- paratus automatically tilts up and the pro- peller clears the obstruc- tion without injury. @e* ss i. - . ; Stopping at a farmhouse to Popular Science Monthly 97 It Stormed; So the Funeral Was Conducted by Telephone ROM Wisconsin comes the report of a funeral by telephone. A Methodist minister, of Oakfield, died and his bishop was to deliver the funeral sermon. But a severe storm came on and the bishop, who was on his way, saw no chance of getting to the village, since traffic was stopped on the short branch line leading to the place. telephone his predicament to the waiting family, he decided to conduct the service over the telephone, one of the members of the family re- peating his words to the mourners. : The Last Word in Fountain Pen Efficiency—An Eraser Attachment F you should make a mistake while writing, the fault is yours, not your pen’s. However, your pen may be made to correct the mistake very neatly. Daniel R. Markley, of Lancaster, Pa., has devised a plan for attaching an eraser composed of threads of spun glass to the top of the barrel of any ordinary fountain pen. The spun-glass threads are encased in a cup which is held in another cup which screws on to the bar- rel of the pen and is covered by a cap resembling the one which covers the pen. The inner walls of the cup holding the bristles, or threads, converge at the outer end so that the bristles are held in a compact little bunch, as shown in the illus- tration. As the bristles at the end are worn away the remaining lengths may be fed through auto- matically by screwing the cup further up. The addition of the eraser does not alter the ap- pearanceof the fountain pen in any other way than by slightly increasing its length. BRISTLE FEED THREAD Css tis Bristles of spun glass are fast- ened in a cup threaded on the barrel of the pen for an eraser Compressed air pumped into the cylinder rapidly vibrates the cutting bar as would a short-stroke reciprocating engine Removing Iron Rivets with a Pneu- matic Hammer HOUGH the pneumatic hammer has long been used in structural steel work to shape the heads on red-hot rivets, the old hammer-and-bar methods are still used in removing the rivets. A pneumatic hammer has been invented, however, which removes fifty times as many rivets in a given time. In the time that one hammer 1j stroke can be given by a man, the pneumatic hammer gives several hundred. The long cutting bar is attached to a piston in a long cylinder. Air is pumped to the cylinder under pressure of. one hundred. pounds. per square inch, and it im- - mediately vibrates the bar violently... When the crew. press. the hammer against a rivet, the pounding. knocks the rivet’s head off al- most instantly. This method. of cutting is not only easier for. the men, but it saves. seventy- five per cent on, the cost of the hand method. More- over, it can be used in ordi- narily imaccessible places. Giving Convicts a Real Chance How the Prison Farms of Florida have superseded the inhuman leasing-out system By Ewing Galloway siaigeeett~ | we 6 A gang of convicts at Bradford Farms grading a lot for an electric powerhouse, ice plant and steam laundry. FEW years ago Florida’s penal sys- a tem was one of the cruelest, the most brutal that ever existed in the United States. All able-bodied male con- victs were leased to private concerns to work in lumber and turpentine camps, and thousands of them were overworked, under- fed, and housed in cages unfit for wild beasts. Often those who failed in the slightest degree to please guards or over- seers were beaten unmercifully. Magazines and newspapers revealed the truth about the lumber and turpentine camps, and as a result of their exposures the State Government established a prison that might serve as a model for agricultural states or principalities throughout the civilized world. One of the two locomotives belonging to the prison is seen in the background Bradford Farms. In November of that year crews of convicts began clearing and draining this tract of wilderness and laying the foundations of some of the buildings. To-day they have three thousand acres in a high state of cultivation, a prison town of thirty-five buildings, all- the implements, livestock and poultry they can use to ad- vantage, and a steam railroad of their own construction running to all important sections of the plantation. Offenders. serving time at Bradford. Farms are not made to feel that they are despised outcasts upon whom the State is. wreaking vengeance. They are treated as misguided persons to be corrected morally and trained for lives of usefulness. They are given In 1913, aft- er thirty-three years of leasing out all convicts capable of earning money for private con- cerns, the State authori- ties bought 17,000 acres of pine forest and swamps in Bradford County and started the de- velopment of wholesome food, housed in clean, airy buildings, en- couraged to improve their personal hab- its, and em- ‘ployed at healthful and instructive labor. The field la- borers work. only nine hours ° a day, which. is about two what is now known as The wards are as light, clean and airy as the State could make them. The men rise at 4:30 and retire at 7:30 98 hours less than the time spent Popular Science Monthly 99 The stables and shops of the model prison farm. The land shown in the photograph was a wilderness of pine forests and disease-breeding swamps before the convicts improved it each day in labor by: the average free farm hand in the South. They take three hours, exclusive of the time spent en route to and from the stockade, for rest and dinner in the middle of the day. They grow cotton, corn, sorghum cane, potatoes and all kinds of vegetables, and raise cattle, hogs and chickens. Last year their Irish potato patch was 550 acres, and an even larger area was given to sweet potatoes. The methods of crop cultivation and livestock raising that have been adopted are the best known to the State Department of Agriculture. The Commissioner of Agri- culture, William A. McRae, sees to it that all the work is done in the best possible manner. The result is that practically all persons released: from Bradford Farms are highly skilled farm workers. The more intelligent ones are well trained in farm management also. At the present time the prison popula- tion at Bradford Farms is approximately 650. About 250 are leased to counties to work on public roads. There are 736 working for private corpo- rations. But the lease law of to-day is not like the old one. It places the working of leased convicts under rigid State inspection, and gives the Commissioner of Agriculture the right to cancel contracts whenever lessees fail to treat prisoners humanely. Only negroes of low-grade intelligence are leased, and the contracts are limited to two years. There is a rapidly in- creasing sentiment in favor of abolishing the lease sys- tem and sending all the This gives an idea of the work the convicts accomplished in converting the three thousand forest acres into tillable land State’s convicts to Bradford Farms during imprisonment, ’ 100 a The inflow of compressed air is controlled by a foot-treadle so that the hands are free to move the block to and fro under the pipe mouth With the Warm Weather Come Im- provements in Ice-Cream Making HE ice-cream manufacturer encounters the same difficulty in removing blocks or forms of cream from their molds as does the average cook or housewife with her frozen desserts. A recent device, patented by L. M. Hendler, of Baltimore, Md., for overcoming this difficulty, is a contri- vance for forcing warmed air througha pipe to the bottom of the mold todislodge the bricks of cream. This is more par- ticularly for the convenience of dealers who handle large oblong blocks of cream which must afterward be cut up into the smaller bricks. The valve which controls the compressed air in- flow is conveniently op- erated by a foot-lever. << —s, The transmission band with cork inserts, encircling a diagrammatic drawing show- ing the band in use on the automobile Popular Science Monthly Why Not Dress Alike and Save Money During War Time? HY not a civilian uniform as a measure of economy in clothing? suggests a Canton, Ohio, man. It could be worn by everyone, man, woman and child, and thus eliminate foolish dressing, the dude, and the spending of hundreds of thousands of dollars on needless finery. It would certainly bring home to the civilian population their part in the war, and the ladies would need to apologize no longer for appearing twice in the same dress. As the ‘ result of investigation carried on by the Ohio man, a standardized suit of wool of excellent quality could be sold for less than twenty dollars. A New Type of Transmission Employs Cork Inserts HE new type of transmission band shown in the accompanying illustra- tion is designed to overcome the objection to the planetary form of transmission, such as used on the Ford car. It has cork in- serts like buttons. These extend out beyond the band proper for a very slight distance and come into direct contact with the revolving drums as the speed is changed. On account of the high coefficient of friction of cork and’ steel, the braking effect commences at once, whereas the plane surface fabric band usually fitted slips as it becomes worn and glossy and does not grip except when an excessive amount of pressure is exerted on the transmission pedal. Then it grips suddenly, : causing a jarring in the operation. The cork buttons also act as springs; for as the pressure increases they are compressed, thus allowing the band itself to come into contact with the drum. “Tiiis makes an easily operated trans- mission which acts positively without slipping, even after long service, and one in which the bands havea _ longer life due to this practical elimination: of the slipping. Popular Science Monthly This Actually Happens Oftener Than You Would Think T may be a mere matter of supersti- tion which causes so many hundreds of sol- diers to wear small Bibles and Testaments over their hearts. But the Pocket Testament League of England re- 101 The Door to This Siberian Home Is ao on the Roof UCH of Siberia is a vast wilderness which still remains to be explored. In the winter season, when the streams cease to flow, disappearing be- neath the ice and snow, the animals hibernate in their dens and the ports that it is very generally done, and oc- casionally we hear of incidents which confirm the report of the League. Superstition says that the heart so protected will never be pierced by a bullet. Certainly the soldier who wore the little volume shown in the accompanying pho- tograph must be a firm believer in its efficacy. He was struck by two machine bullets. One of them remained in the Testament, though prac- tically destroying it. The other passed through it and penetrated his ribs, but without causing seri- ous injury. Superstition also says natives repair to their huts to sleep away, so far as possible, the in- finite silence that broods over the land. The illustration shows the interior of a Siberian home. The odd-looking ladder in the foreground leads to the door of the hut, which is situated in the roof. The ladder is hewn from a big log and the hole rungs in it have all been cut by hand. It is necessary to enter a Siberian home through the roof during the sever- est winter mcnths, be- cause the snow, driven by the gales of the North, forms great drifts which not only effectu- that if the Testament be -the gift of a mother or sweetheart it is doubly valuable as a talisman. © Press Illus. Serv. Notice the face on the right-hand page. Two bullets pierced the little pocket Testament without doing the wearer any serious harm The Siberian native enters his home by a ladder leading from a door in the roof ally cover up all side entrances but often con- ceal the whereabouts of the hut itself. Have You Put the Cat Out for the Night? Then Don’t Says Lee S. Crandall, in Pets (Henry Holt & Co., New York): ‘The practice of turning the cat out of doors at night is as cruel as it is unnecessary. No animal is fonder of warmth and comfort, and the pet’s happiness certainly is not increased by a night spent outside in cold and dampness. “‘If as much energy were exhausted in keep- ing the cat indoors as too often is expended in putting her out, how great would be the boon to human nerves and unfortunate wild things! All felines are vormally nocturnal, and it is at night, if ever, that a curb on their activities is needed.” ‘ The Problem of the Automobile Top It may be made self-effacing and self-adjusting HALF UP, POSITION pepe ncweseerscese* UP POSITION, CABLE DRAWN THROUGH HOLLOW WINDSHIELD POST Seiten — a <#CABLE , = I Die, Bie LACS Oj = hat mi ly ke | | mutt | ill ii i | Se seem raphy s —— - The metal of a discarded factory tank pro- vides an excellent housing for the automobile covering in the shape of an inverted U. A framework was made of wood and placed on the ground. To this the sides and ends of the tank were attached. The metal which was carefully removed from the end and side, was used for making the doors, which were hung on ordinary hinges riv- eted to the metal of the tank. A flashing was attached above the door to keep the rain from beating in back of the doors. A window could easily be placed in the oppo- site end to furnish additional light if de- sired.—CHARLES CLAUDE WAGNER. A Cheap and Effective Method of Bracing a Roof ie many instances the partitions of frame buildings do not allow the rafters to be effectively braced from them, so that Bracing a roof to provide a space in the center not obstructed with timber supports trussing is resorted to. spoils any room directly under the roof. Popular Science Monthly than trussing, is cheaper, and provides a stronger brace. Also, it does not interfere with the space under the roof. The trussing consists of two 1 by 12-in. boards the exact length of the distance be- tween the front and rear plates. As many 1 by 3-in. pieces are used as there are rafters. These should be the length of the distance between the bottom edge of the outside rafters and the top edge of the ' plates at a point half way down the rafter. Nail these on the boards as shown, after having laid out the location of the rafters on their surfaces. Be sure that the ends of the bracing pieces are all in line. Then adjust each board under its side of rafters in an inclined position so that the ends of the braces catch under each rafter, — supporting the ends on the front and rear plates of the building, and elsewhere on any partitions there may be in the en- closure. The upper edges of the boards are further braced with 1 by 3-in. strips nailed. to the top edges and to the side plates. This keeps the top edges from bulging or moving. It is now only necessary to sight each rafter, slightly moving the braces until the rafter is properly lined and then , | to secure it with nails—HENRY SIMON. Small Closet in Door-Frame Stile ! for Milk Bottle te HE question of where the milkman shall put the milk bottles in the mornings in order to prevent them from being stolen, upset by dogs or cats, or from smearing the porch or steps has been answered in many ways; but the neatest and best device for the purpose which I have yet seen is a little closet cut out just above the floor in the kitchen, between the inner and outer wall of a cement bungalow. The space between the walls is a little wider than the diameter of the ordinary quart bottle of milk, and a length of the side wall was cut out sufficient to accommo-. date about four bottles. An inner door is provided so that the bottles may be placed in the little closet and the door shut from the inside. An outer milkman may unlatch it, take at out the empty bottles, set in the — fresh supply and close the door again leaving no trace of the This, however, . milk visible. This outer door overlaps the opening, somewhat, so that no draft is ad- The method illustrated is more effective. mitted through cracks.—JAMEs A. CARTER. _ door is also provided so that the \ ' and at the same time the most exacting of athletic events, requiring _ strength, speed, and skill. A left-footed _ jumper should grasp the pole with the _ ordinary left-hand grasp and the right hand _ reverse grasp, hands 30 in. apart. For the usual vaulter the right hand grasps _ the pole according to the following instruc- _ tions: When the bar is placed 9 ft. high, _ the right hand is at 9 ft. on the pole; for _ each foot that the bar is raised the right Bp Sand is lowered 4 in. Carry the pole on the right side with the point directly _ forward and raised a little. Run squarely _ to the front, avoiding a twist. : The take-off or jumping spot should be _ directly under the right hand when the _ pole is planted ready for the spring and _ the striding marks placed accurately at about 40 and 80 ft. from the stands. _ These marks must be placed so as to help _ produce accurate running, as described in the high jump. During the run, look at . a pole vault is the most spectacular these marks. Start to run at about 100 ft.’ Taking the Jump Plant the pole lightly by thrusting the _ end into the hole just before the left foot strikes the take-off. At the same time _ throw the arms forward up and slide the left hand up close to the right. The arms at this point should be almost straight, the _ hands above the left foot or a few inches _ in front of that spot. Any other spot for the take-off will strain the chest or back muscles, and if the arms are too straight or _ too much bent you cannot rise well. The left foot should be placed upon the take- _ off a couple of inches to the right of a line _ drawn directly back of the point of the pole. The hole for planting the point of the pole should be 6 in. toward the runway from a point just under the bar. In the rise, swing the body forward at arm’s length to the right of the pole, facing directly forward. When half-way up to the bar flex the thighs and legs so that they are above the head and the bar. Now ~ Winning an Athlete’s Laurels IV.—Pole vault and potato races By Albert B. Wegener A technical instructor and director of athletics of twenty-seven years’ experience straighten out, turn to the left, pull up and push up strongly with the arms. This brings the hips above the bar and facing it in an arched position with thighs flexed. Now push over the bar and release the grasp, with the left hand first, allowing the pole to drop back. Alight facing the bar or with an additional turn to the left. Training Hints For several weeks before attempting to vault, practice the following developing exercises: On the horizontal bar, chin several times; then do the same and circle backward over the bar. Circle forward over bar. Hang and raise feet to the bar. Free backward circle. Pull up and shoot over a cross-bar placed 2 ft. in front of and as high as the bar. Practice walking on the hands. Do the hand balance against the wall, then bend and straighten the arms. Practice the rope vault. Prac- tice sprinting and jogging. When starting to use the pole do not try to vault over a cross-bar for a few weeks, or until the movement is_ thoroughly learned. Preliminary practice with the pole should be, planting the pole and using the grasp at about 8 ft. high. Plant the pole and swing forward. Plant, swing, and rise. Plant, swing, rise, and pull up, etc. Introduce the bar only when able to do about 8 ft. without it. Do not vault more than ten times a day. Give much attention to massage. If sore and stiff, rest and massage. Other Styles of Vaulting For those who have not the time to devote to learning the exacting shift-hand style, and especially for boys, the no-shift style is recommended. In this the hands are held about 2 ft. apart and neither of them is moved from that position until after the rise, swing, pull up, and shoot over are made. It is impossible to go high with this, but it is much easier and safer than the other style. The Vault for Distance is an event seldom, if evgr, now used in 141 142. meets, but it would be more appropriate for boys than the vault for height. The action is much like the above styles except that there is no necessity for getting so much of a “‘lift.” Vaulting Rules The height of the bar at starting and at each successive elevation is determined by the field judges. Each competitor is allowed three jumps at each height, and the competitor who fails at the third attempt is disqualified. SIOprw- rar wen (S05 ons). Las 6-3 HOLE FOR POINT OF POLE . ' ' ’ ‘ i] ‘ ] ' t) ‘ r] |@ LEFT Foor eo" if 7 TAKE OFF ' ‘ FLOOR PLAN FOR A RIGHT HANDED VAULTER Popular Science Monthly “‘balks’’ are always counted as a trial jump. Any competitor is allowed to dig a hol not more than 1 ft. in diameter at the take- © off, in which to plant his pole. A competitor must not, in the moment that he makes a jump, or after leaving the ground, place his lower hand above the upper one or move the upper hand higher up on the pole. ween Ze 8 SJ le Sans Plant the pole lightly by thrusting the end into the hole just before the left foot strikes the take- off and at the same time throw the arms forward with the left.close up to the right exactly as above A competitor may commence at any height above the minimum height. He must, however, jump at every following height until he has forfeited his right to compete further. The vault is made over a bar resting on pegs. As soon as a competitor has left the ground for the purpose of making a jump, the jump is counted as a trial. A line is drawn 15 ft. in front of the bar and parallel therewith, to be known as the balk line, and stepping over such a line, or such line extended, in any attempt is counted as a “balk.’’ Two successive Poles may have a binding, but must not: — have any further support for the hands. If the uprights are moved at all they must not be changed more than 2 ft. in any direction, and not more than one hole may be made by a competitor. The take- © off ground about the jump must be level. - The uprights should be at least 12 ft. apart. vad All measurements are made perpendicu- larly from the ground to the upper side’ of the bar where it is lowest. In the pole vault, if in making a trial the competitor’s pole is broken, it is not counted. as a ‘trial. FP ae Oe ee eT, ee The rules governing the running broad mp also govern the pole vault for distance, except that when the man leaves the ground 1 an attempt, it is counted a trial. _ If the uprights are moved, the field wale should make a_ re-measurement, 4 use if there is any inequality in the ground at all, changing the uprights may make a difference varying from 1 in. to 4 jn., and a competitor should not be allowed _ to obtain an advantage in that way. Indoor Athletic Events Indoor athletic events are quite as ‘popular as outdoor events, and have _ the advantage in large cities of being more easily promoted in gymnasiums, large halls, and armories, and of not being subject to the weather. With certain modifications most of the outdoor events ‘can be conducted indoors. _ Among the most popular indoor running events are the sprints. These are run either on the main floor or on an elevated track. If run on the main floor the distance is limited by the length of the room. Nothing below 25 yd. is considered satis- factory for “‘straightaway’’ running. When a circular track is used any distance may be run; but contestants cannot, in _ most places, start side by side on the same _ mark, on account of the narrowness of the track. For that reason the contestants _ must run either singly or two may start so as to finish directly on opposite sides of the track, thus allowing the judges to sight across and determine the winner. The _ most popular arrangement is to have four runners start and finish from separate marks a quarter distance around the _ track, each runner being timed by a set of watches. This is as close to a real sprint as can be run on a narrow gymnasium _ track. None of these methods is without objection for narrow track sprinting, and _ for that reason are never used in important _ meets. In such meets the sprints are _ limited to the straightaway on the main floor and nothing less than a half mile is scheduled on the narrow track. But the other methods may be used with profit in closed meets and where absolute condi- tions are not demanded. For straightaway sprinting on the main floor there is no difference from outdoor sprints, but for narrow track sprinting the start and “taking the curve’’ must receive special notice. Toe-blocks cannot be used on such a track. Thus the runner is al- iM = Popular Science Monthly 143 lowed to brace his rear foot against the foot of another person at the start. In running around the banked curve a sprinter will make the best time by running up high on the outer edge and inclining the weight well in toward the rail. In track events of a half mile or more the contestants start together at or near the same mark, except of course in handicap races. Such races on a narrow track are not always satisfactory because it is almost impossible to pass a runner in the lead without fouling. The only way that this difficulty can be lessened is to insist that the ‘runner up’? must take the outside and the runner ahead keep the inside of the track on the ‘‘straightaway”’ part, and allow no passing on the curve. Indoor hurdling has been found to be very satisfactory. It should never be at- tempted on the narrow elevated track usually constructed in gymnasiums. In- door hurdling, whenever it is scheduled, is always run as a straightaway on the main floor like the sprints. It is seldom possible to have more than two hurdles at the regular distances. It is, of course, possible to place the hurdles about 6 yd. apart and use a single stride between hurdles, thus using more hurdles. Relay Races in the Gymnasium Indoor relays, like all other sprints, are never run side by side like outdoor relays, unless run in an exceptionally large room with at least a 220-yd. track wide enough for that purpose. Relay races may be run on the regular gymnasium track, but only two teams can run at a time, and these must start from opposite sides of the track. Such races are popular and should be scheduled in all indoor meets. They are usually made short—one or two laps for each man—because the winning team must run repeatedly. Uprights should be erected on each side of the track opposite the center across which the judges sight on the finish. All runners should line-up on the inside of the track so as not to interfere with the other team as they pass. The starter should stand at the end of the gymnasium rather than near one of the teams. One judge should be stationed on each side of the track at the finish line. Rules about passing are the same as in other narrow track races, but because fouls are almost unavoidable it has been found better to allow no passing. Such races are 144 popular as a feature of regular gymnasium class work in which there. are many on each team. Novelty relays are not used in serious meets but are popular as diversions at @p rors je 4 oe / al # Berl bess J, the drawing. Raney Oe esa, The hole is par- Gy RSH eee tially filled with 8 sc corse wet earth, here gen Pa marked B, leav- ing room for more concrete. The upper con- crete block should be about 50 percent larger than the lower block to offset any difference in the hardness of the ground. There is practically no strain exerted against the ground between the two con- crete blocks.—RoBERT W. PHELPs. The part of the hole be- tween blocks filled in with dirt Waterproofing Blue Prints and Drawings for Rough Handling HEN blue prints are handled to a great extent or when it is necessary to use them outdoors, as in construction work, they often become spotted by water or soiled; which makes the prints difficult to read. Waterproofing them protects them from the water, and makes it possible to wash them off when they become soiled. The waterproofing can be accomplished by dipping the prints in melted paraffin wax and hanging them by the corner to drain. Another method, not so clumsy, is to immerse heavy blotting paper in the wax and when cold lay the print between two of the sheets and pass a hot iron over them. These processes are applicable to all kinds of papers.—THOMAS Ww, BENSON. 146 A Coating Which Gives the Appearance of Stone to Wood O make imitation stone for outdoor furniture, sun-dials, flower pots, etc., the following can be used: 10 parts lime 12 parts rosin I part linseed oil Dissolve ingredients thoroughly and ap- ply the mixture while hot to thé wood as a coating. The result will be an attrac- tive stone-like appearance that will last indefinitely —L. E. FETTER. A Special Ladder for Use in Boiler Shops HE type of ladder illustrated is especially made for use in boiler and car shops where it is necessary to climb up to,moderate heights for doing work. Being of the A-type it can be used like a painter’s ladder and a plank can be put between two of them to form a trestle which will ac- commodate more than one workman. This method of construction makes the best pos- sible ladder—strong, safe and economical. It is built of short pieces of 114-in. pipe, each about 2114 in. long, which may be picked up about any shop where con- siderable pipe is used, such short pieces being useless for general work. r | PIPE 5 ne oe meaeegs| An A-shaped ladder made of short lengths of gas pipe and fittings for a boiler shop The pipes forming the rungs are I in. in diameter. In the making of the ladders illustrated, sixteen 114 in. by 1 in., brass tees and eight 3%-in. bolts, one for each rung, Popular Science Monthly were used in each ladder. The parts were hinged at the top and _ pointed irons were fitted in the lower ends as shown. A chain is used between the parts to keep them from spreading. While this ladder is very heavy, yet for the usage to which it will be subjected the construction is most desirable and at the same time inexpensive.—JOsEPH K. Lone. Three Plates and Three Color Screens Used in New Color Photography ib a recent patent on color photography there is brought out a process whereby three sensitive plates are placed together in such a way that the color screens in in them produce the desired effect on the plate. OPAQUE BACK SCREEN AP ED RA : Y To obtain CARRIER GLASS: N these results it RED-SENSITIVE COATING BLUE RAY is necessary to have all plates that are used in sets, sensi- RED COLOR-SCREEN GREEN-SENSITIVE COAT! CARRIER tized at the same time, so that they will age the same and have the YELLOW COLOR-SCREEN BLUE-SENSITIVE COATING CARRIER GLASS Bie ng WAM MA AAMT MAAN RR CAAA AVA Arrangement of plates in pack to record natural colors same emulsion. The ordinary dry plate is sensitive to the blue rays. In making up the sets green- sensitive plates must be used, which are sensitized with a chemical dye. A batch of these plates is divided into two parts, the first portion being coated on the back with opaque substance and allowed to dry, after which they are treated for rendering them red-sensitive. In the meantime, the second portion of the plates, which are already green-sensitive, are superficially coated with a temporary green. Then they are assembled to form a plate pack, and if desired, a blue-sensitive is combined with them. By securing these together they make a unit which may be exposed in any desired manner. After exposure the plates are separated, developed and fixed. The chemical dye which gives a plate sensitiveness for a given color may be termed a color-sensitized agent and the plate a dye-sensitized plate. The green- sensitizing agent is preferably included in the original emulsion. The illustration shows the sensitive plates and their arrange- ment in a pack to record the natural colors as the rays fall, upon them successively from the camera-lens, Applying Insulation to Splices Made in Electric Wires comply with the rules of the American Institute of Electrical Engineers, it is necessary to apply a rubber coating over a soldered joint in a wire. One of the best methods of doing this is to lay on the rubber over the splice before it begins to cool from the soldering operation. The thickness of the coating depends on the amount of voltage carried in the line. Cover the rubber insulation immediately with friction tape, drawing it tight, while putting on a sufficient number of layers to stand the wear. To make a neat covering, cut the friction tape into narrow strips, less than )% in. wide, and a smoother joint will be the result after the wrapping. If this is done neatly and drawn tight enough there will be a noticeable bulge in the joint. This can be easily wrapped with a cord—silk if the case calls for it—then given a coat of shellac. If the proper color cord or silk is selected a joint that cannot be easily detected results. A Simple and Easily Made Electric Battery Motor SIMPLE and easily made motor that will run at high speed with two or three cells of dry battery, or on an alternat- ing current with a transformer, is shown in the illustration. While this motor can be made in any size that will appeal to the experimenter, only one dimensioned draw- ing is given. Procure two hexagon-head bolts, A, 2% in. long and \% in. in diameter under the head, also some thin hard fiber tubing 14 in. inside diameter to slip over the bolts. Cut two pieces B, each 2 in. long, and fit on heads or washers, C, about % in. in diameter, leaving 14 in. of the tubing projecting at the threaded end. This forms the spools for the magnets. Amateur - Electrician y And Wireless Operator Wind the spools with No. 22 or No. 24 magnet wire in the usual manner having the inside as well as the outside ends come out at the back end of the magnet. The soft iron standard D is about 3 in. high, 14 in. wide and % in. thick and bent L-shaped at the lower end to form a foot by which it is screwed to the base. In the standard are drilled three holes. Two of. these are of the same size to allow the ends of the bolts or magnet core to enter and project on the outside for the nuts, which. hold the back ends of the coils in position. The third hole is located centrally between Universal motor that will run on a battery current or reduced alternating current the other two to accommodate the shaft. The same number of holes and in the same position must be drilled in the brass yoke for supporting the front ends of the magnets and the front bearing. This brass yoke may be a flat strip about )% in. wide and of a length to cover the front ends of the coils. When the bolts are put through the magnets the protruding ends of the fiber tube will butt up against the back standard and all parts will be held securely in place. The armature poles F consist of soft iron buttons about % in. in diameter and \% - in. thick, connected by a strip of brass % in. wide, having a hub,in the center for 147 148 fastening it to the shaft. The balance wheel may be made to suit the fancy of the builder. Before assembling the parts, a commuta- tor must be made and slipped on the shaft back of the standard or between the up- right and end support. As it is necessary to have a break in the current for a short ae Vz BRASS TUBE ia Mena Tal fe aed | a TO STANDARD TO BINDING _BOTH INSIDE ENDS POST TO OPPOSITE SOLDERED BINDING POST AND BRUSH The parts and their assembly for the construction of the universal motor period a part of the commutator must be insulated from the shaft. This is ac- complished by making a base G cut from a hard fiber rod which is drilled to slip in the shaft. A brass tube having an inside diameter to fit on the fiber rod is filed as shown at H, and when assembled it appears as shown in the illustration on page 147. The brush-holder for making contact on the commutator is constructed as shown at J. The base is made of hard rubber, or fiber 1) in. long and 4 in. thick. One end is rounded and drilled to slip over the core or lower bolt between the standard D and the magnet end C. The thin brass spring makes contact with the metal strips on the commutator as it revolves. Both inside and outside ends of each coil are brought down through the base in rubber tubes. The inside ends of coils are soldered together. One outside end is connected with the iron standard D, and the other outside end witha binding post. The remaining binding post is connected with the spring on the brush-holder.—W. E. Day. Popular Science Monthly Rebuilding Worn-Out Dry Battery Cells HE most difficult part of rebuilding dry cells in quantity is the removal of the contents, which consists of peroxide of manganese and carbon powder tightly compressed and covered with pitch. Strike the pitch a sharp blow with a hammer to break it; then dig it out with a pointed tool like that of a screwdriver. Save the pitch and sand in separate receptacles. The compressed oxide and carbon are also difficult to remove. About the only quick method is to use a twist drill % in. in diameter, placed in the chuck of a lathe. By pressing the zinc-cylinder of the cell on the drill and boring several holes in the compressed material to within 4% in. of the bottom, you will break it up so that all of the compound can be readily removed. Save the borings and the crumbled mass. If a small portion is left at the bottom it may be easily removed with the aid of a screwdriver. The material removed is spread out to dry and any lumps found -are crushed. The exposure of this material in a thin layer not only permits the moisture to evaporate, but brings about a certain amount of reoxidation of the spent manganese dioxide. As soon as the ma- terial has become dry it must be heated to a moderate temperature—about 400 deg. F. will answer, but not to a bright red, as this will drive off some of the oxygen, every bit of which is needed in the renewed cell to act as a depolarizer. During the heating, which may be readily done in a stout iron pan, it must be well stirred. This process will eliminate a very large part of the exciting salts used in the original cell. The heated material must then be spread out and exposed to the air to cool. When cold it is ready to be mixed with the. exciting salts and repacked in the original zinc-cylinders. Almost all the cylinders may be used again after being soaked with hot water for about 1 hour or more. The soaking will loosen the original paper lining and it can be easily removed with a pointed tool inserted between the cylinder and the lining. Finally clean out the interior with a stiff brush and wet sand, or with a wire brush. When the cylinders are aired they are ready for re-filling. Some of the cylinders will be used up and unfit for use again. These may be dissolved in hydro- chloric acid to form a strong solution of chloride of zinc, which is required to make up the exciting mixture. In preparing _ chloride of zinc, the scrap-zinc should be _ placed in a large stoneware crock and 3 or 4 |b. of commercial hydrochloric acid poured over it. This must be done out- doors, because the hydrogen gas that is given off is harmful to breathe, and also inflammable. A great heat is generated and the liquid may boil up and make it run over the top of the crock. A small quantity of cold water may be poured in to lessen the chemical action without detriment to the resulting product, which should be left until quite cold before using. It is very important that this solution should contain no free hydrochloric acid, because its introduction into the made-up cell would cause chemical action, and the cell would soon be destroyed. Any trace of free acid is readily dispersed by adding a small quantity of chloride of ammonium in powder form and stirring the liquid until effusing ceases. By this method a small quantity of chloride of ammonium may be introduced without harm. As soon as the solution of chloride of zinc is ready it may be strained through a piece of damp muslin to free it from dirt, paper chips and other matter, and then filtered through a tuft of cotton pressed in the neck of a glass funnel. This will free the solution of any fine iron-deposit or lead that may have been in the zinc, thus aiding the efficiency of the re-made cell. This solution should test 32 deg. Baume. Sal ammoniac, or chloride of ammonium in the crystal form, is then dissolved in the chloride of zinc. Filtered or distilled water is then added and the mixture stirred well and tested to register 32 deg. Baume. The solution is then ready for use. The carbon-rods and the brass binding- posts and screws must be cleaned and the zinc-cylinder lined with a double thickness of blotting-paper, or blotting-board, cut so as to leave a margin of about 14 in. at the top where it is turned over on the outside. Cut some circular pieces of cardboard, or heavy blotting-board, so that they will fit tightly into the interior of the blotting paper. Press three or four of these down into the bottom of the blotting-paper lining inside of the zinc-cylinder. It i is then ready for filling. Just before putting in the mixture pour in some of the chloride solu- tion so as to wet the paper all over, drain it and place the zinc upside-down to drain off the excess liquid. This takes about Popular Science Monthly 149 20 minutes, for the paper must not be over wet. Then place upon a smooth board about 14 lb. of the carbon and manganese powder that has been treated. Add about 3 oz. of the chloride of zinc and chloride of ammonium solution and mix well so that it will hold together when gripped in the hand. It must not be very wet or it will not give the proper amperage. The right consistency is very important. Pour some of the carbon mixture into the paper-lined zinc-cylinder and ram it down hard; insert one of the carbon rods, adjust it centrally, then pack some of the mixture around it and ram it down tight with a suitable strip of wood, hammering it in with a wood mallet. The carbon rod must be tapped down occasionally to prevent it from lifting. The tighter the mixture is packed the greater will be the amperage when finished. Cut off the outside edges of the biotting paper and fold the top of it inwards toward the carbon-rod, press it down and see that none of the carbon mixture makes contact between the zinc and the carbon-rod. This is essential as the connection would short circuit the cell. Place all the binding screws in position, test the cell with a suitable battery ammeter and see that the screws of the carbons are tightly fitted. It should give a current of 15 to 22 amperes. Dry the sand and pack some of it over the top; then melt the tar and pour it on the sand to completely fill the cell to the top. These made-over cells will give an excellent working current for a comeiterable length of time. : Method of Insulating ERIE “Pies” in Transformers N most text-books on the construction of transformers, it is customary to advise the insulating of the ‘‘pies’” or sections in the secondary winding by means of long strips of empire cloth, wound over and over through the center holes of the sections. This requires a good deal of work on the part of the constructor. While overhauling a transformer, the writer tried out a somewhat novel method. The core was insulated in the usual manner, with a number of layers of empire cloth, but the “‘pies,”’ instead of being wound with strips of empire cloth, simply had round disks of empire cloth, of double thickness, between each pair of sections. This gave fully as good insulation, and made access to the different sections easier. 150 Steadying the Voltage of a Dynamo Driven by Gasoline Engine HIS problem has been solved in various ways. We are all familiar with the storage-battery system, and being ac- quainted with this system, realize its ex- pense. If a gas or gasoline engine is to be used to drive a dynamo, some G provision must ._— be made to Z steady the speed of the dynamo. Cast iron fly-wheel see ek: pulley Bronze bushing Pe | LAXMI SQN ti OF 2" Wrought iron pipe sf shaft A spiral spring in flywheel hub on an armature shaft to prevent flickering of lights HA \\ Every time the engine ex- plodes, there is a momentary increase in the speed of the dynamo, causing a fluctuation of voltage, and a flicker of the lamps. Special engines with extra heavy fly-wheels have been built for this purpose, which give fair results, provided that the armature of the dynamo has a large moment of inertia. Ifa flywheel is put on the dynamo, the voltage fluctuation is lessened, but this induces belt slipping, and hence. loss of power. Specially built electric lighting engines are expensive, and for small plants of from one-half to two or three kilowatts give but little satisfaction. The writer has obtained satisfactory re- sults in a one-kilowatt plant by using the spring flywheel arrangement shown in the diagram. The belt from the engine drives the pulley on the flywheel which is fastened to the pipe. The pipe in turn twists the end of the helical spring. The other end of the spring is fastened to the flywheel. In this way the impulses from the engine are spread over a longer interval, and the tendency is for the dynamo to run at a constant speed. The whole spring is packed in grease, so that there is but little loss of power from friction. Belt slipping is avoided by the freedom of motion of the pulley and pipe. The momentum of the dynamo flywheel tends to keep the speed of the dynamo constant while the engine 4g Popular Science Monthly is slowing down on the compression stroke, and likewise while the engine is on the power stroke, the spring operating © as an elastic medium between the driving pulley and the flywheel. he spring must be made of steel of exceptionally good quality, on account of the rough usage to which it will be exposed. I used a No. 10-gage spring steel wire. This wire was made up into the form of a coil spring and then tempered. A spring was tried which was made of spring steel which had been tempered before it was made into the spring. This spring lasted but a few hours, after which time it was distorted beyond usefulness. The results with the spring were com- pared with those without the spring, by first running the machine with the pipe clamped fast to the flywheel spindle, and then running the machine with the spring free to operate. In the first case there was a variation of between three and four volts upon each explosion of the engine; in the second case this variation was reduced to less than one volt, the plant operating at 110 volts. The power losses arising from this arrangement were negligible. Increasing the Voltage of a Dry Battery FTEN a battery of dry cells will fall in voltage or become reduced in pressure because some of the cells have polarized, consequently the current is not sufficient to operate the ig- nition of an en- gine or to per- form its duty. Such an occur- rence is likely to prove very an- noying. In emergency cases the voltage can be increased temporarily by taking a good cell from the set, cutting it in half and then making the connections as shown. Slip the container out of its casing to make the cut and connections, then put the two parts back so that the cell will have the same appear- ance as before. This reduces the ampere hours, but it bridges over the difficulty. CARDBOARD INSULATOR CARDBOARD INSULATOR WR} WITH HOLE CUT IN CENTER A good cell cut in half to produce more voltage a ee My Ee a got Peers Keyless Lamp Socket for Switching Electric Currents _* THE well known key socket for electric lamps requires at least thirty separate and distinct pieces, the assembling of which is an important item in estimating the cost _ of production. A new socket has been devised which may be. made of less than half the usual number of parts. Instead of having a key the bulb itself serves to switch the current on and off. Pushing the bulb inward about a quarter of an inch causes a spring finger to snap in- to contact to connect one side of the circuit, while the central contact point of the lamp is caused to engage with the terminal of the other side of the circuit, thus turning on the current without a push button or switch lever. In order to cut off the light, the lamp is * drawn back so as to sever the connections, the act of push- ing in or draw- ing out the bulb being far less injurious to the threaded end of thesocket, or to the fixtures, than the turn- ing operation of the key. ’ The drawing shows the socket made of two parts, the lower end, which is threaded to receive the lamp, being adapted to slide within the upper portion that is attached to the fixture. An upwardly-projecting spring finger, the lower end of which is attached to the inside of the lower shell, has its V- shaped upper end normally resting within a recess formed through the insulating material, so that when the bulb is pushed upward the V-shaped end is caused to snap over and engage with one terminal, while a spring finger on the opposite side of the insulating block contacts with the central terminal of the bulb. It will be observed that by this arrange- ment both terminals are out of the circuit when the electricity is cut off. By loosen- ing the two screws which hold the shells together the entire working parts may be withdrawn, together with the insulating block, affording a convenient and readily accessible means for attaching or repairing the wires.—J. S. ZERBE. A part tarn of the socket switches the current on or off Popular Science Monthly 151 Curious Circuit for Audion On a Wireless Set T has often been said that it is not possible to use an audion bulb in con- nection with a simple double slide tuner. But experiment has proved that a hook-up may be tuned very closely Diagram showing an audion bulb in con- . nection with a simple double slide tuner al and accurately, the strength of signals from all stations being much greater than when the same audion is used with a receiving transformer. On a single-wire aerial 50 ft. high and 150 ft. long, the time signals from - Arlington were received. over 500 miles . under all weather conditions. As will be recognized by those familiar with vacuum bulb circuits, the arrangement shown is very different from the normal arrange- ments on the usual wireless set. Conversion of Kilometers to Nau- tical and Statute Miles IRELESS telegraph transmission dis- tances are often stated in kilometers, nautical miles or statute miles. To convert the number of kilometers to nautical miles, multiply by fifty-four and point off two decimal places. To convert from kilometers to statute miles, multiply by sixty-two and point off two places. If the distance is given in statute (or land) miles and you want it expressed in kilometers, multiply. the number of miles by 161 and point off two decimal places. An Experimental Wireless Aerial Made of Zither Strings HILE experimenting with several dif- ferent types of novel aerials I found that by connecting together all the strings of a zither and substituting it for the aerial with an inductive coupler, fixed condenser, silicon detector and a pair of 2000-ohm telephones, I could hear a number of local stations very clearly —Hs DrosBeE. 152 : The Effect of Electricity and Music on the Human Organism HE effect of music upon the human organism, whether calming, exciting or otherwise, can be reproduced in a re- markable manner by means of electric currents. Dr. M. Dupont is responsible for much of the successful research in this direction and has obtained results that are not only interesting but of probable educational and medicinal value. Music consists of sound vibrations at certain regu- lar intervals. For a high note the vibrations are very rapid, while for a low note they are slower. To produce musical effects by electricity the alternating current is em- ployed, made up of periods, the frequency of which corresponds with the number of vibrations of the sound; that is to say, with the pitch. Upon passing the alternat- ing current through the body in the form of a mild shock an effect is produced similar to the physical thrill of appreciation for a musical performance.—H. J. GRay. _ To Prevent the Ears from Perspiring When Using Telephones O doubt the wireless operator has often had the annoying experience of per- spiring ears. This inconvenience can be easily overcome in the following manner: Take a small piece of paper slightly larger than the receiver and place it between the receiver and the ear. I have found this to stop all perspiration without im- pairing the hearing.—W. T. DERR. A Rain Alarm Made of a Broken Electric Globe OW often the rain pours into a window at night and we know nothing of it until we awake and find the floor and carpet damaged! This can be avoided by installing a simple rain alarm which will ring an The electric lamp biitacet 3 on a wood base and the connections with the binding posts electric bell. To construct such an alarm proceed as follows: Remove the upper part of a carbon filament lamp by winding Popular Science Monthly a piece of cotton string around-the lamp — just above where the platinum wires come through the stem. Saturate the string — with kerosene, applying a lighted match, and, while the glass is hot, dip it into water. Bell Wiring diagram showing the alarm gage ‘in- stalled in a battery circuit for ringing bell Screw the lamp into a porcelain receptacle mounted on a board. Make connections with a bell and two dry cells, as shown. Then place the lamp outside the window and fill almost to the platinum tips with dilute sulphuric acid. When a few drops of rain fall into the lamp, the solution, which is a good conductor, will cover the platinum tips and form a circuit, and thus ring the bell. The switch should be put near the bed where it can be turned on and off conveniently.— WM. WARTHEN. Mounting Tinfoil on Glass Con- denser Plates GOOD shellac for fastening the foil to the glass in transmitting condensers “may be made by dissolving as much pow- dered rosin as possible in 1 oz. of turpentine and thinning the mixture by the addition of % oz. of alcohol. Only a very small amount of rosin will be needed. About three drops of shellac should be put in the center of the surface of the glass and rubbed around well. Place the foil on the glass and roll it fast with a photo- graphic print roller. The foil must be placed on at once as the mixture dries quickly. When this varnish is used the plates may either be stacked or made into an open rack condenser. If plain turpen- tine is used the foil will not stick so well and consequently the plates must always. be stacked.—SAMUEL W. HurFrF. ‘How Germany’s Secret Service Wireless Stations Are Being Weeded Out "T°HAT there are secret service wireless stations of Germany in and about our large cities and important harbors, there is - not the slightest doubt. At the time the _ merchant submarine ‘‘Bremen” was to arrive from Germany, it will be remem- bered, German agents prepared moorings for her at New London, Connecticut. Neither the Government wireless stations nor our commercial stations received any communications from this submarine. Evi- dently, secret stations, whose messages we - could not hear, must have kept in touch with her. These stations, we can rest assured, have not dismantled, but are working now. They await only the opportunity to report the sailing of a Europe-bound ship to a sub- marine waiting offshore. Unquestionably, such a menace must be weeded out. Our Government has not been idle. According _ to reliable information, it has already - located several of these stations. The _ problem is not an easy one, and is one entirely of wireless engineering. William Dubilier, one of our most prominent experts, believes that the Ger- mans manage to keep their antennas con- cealed by stringing them inside high non- metallic structures; as, for instance, a hollow wooden flagpole. Though but one wire could be strung inside a flag- pole, what would be lost in antenna efficiency could be partly compensated for by the increased power of the station. Of course, these spies would not be compelled to use an aerial at all. Popular Science Monthly They 153 could use’a close circuit system having two grounds. But this is not likely. The other method is more efficient and lends itself to better selectivity. From the antenna concealed in the flag- pole, the spies could run the aerial lead directly through the roof and into the ‘garret of the building, without exposing it. These instruments, we can take it for granted, are the best that German money can buy. The operators obtain their unusual selectivity probably by the use of a double heterodyne or ultra-ultra system. That is, they superimpose a number of oscillation circuits one upon the other between the exciting transformer and the aerial and ground connections. The various ways in which each of these many circuits can be tuned are almost unlimited. The waves such a system would send out could be efficiently received only by a receiving system of similarly complex configuration. The usual station which has not these superimposed circuits could not receive the signals distinctly. These facts give some idea of the task our wireless engineers are up against. First, they must obtain a circuit which will receive these secret signals—a most-difficult task which would involve the finding of the exact number of the superimposed circuits and the exact configurations! Second, they must locate the stations with some sort of direction-finder using this type of circuit. The methods used with these finders would then be similar to that explained in a previous article on the direction-finder, on page 232 of the February 1917 issue of the POPULAR SCIENCE MONTHLY. The Germans conceal their aerial in the hollow of the flag pole. Their complex waves can be ‘received only by submarines and other stations fitted out lik@ themselves 154 Electric Experimenting Table Made from an Old Commode N old commode such as is very often discarded or sold for little or nothing can be very easily and cheaply transformed into a high class electrical experimenting workbench in the following manner. First procure a nice smooth board and nail it firmly to the two uprights 4, which are found on nearly all old commodes. This forms the switchboard 8B, upon which all switches, rheostats, meters, etc., can be conveniently mounted. In the accompanying drawing, a very convenient arrangement is shown. The dry cells, storage battery, or transformer is placed in the little cupboard C, at the bottom of the stand, from whence the two wires lead to the switchboard and are there connected as the user may see fit. All the wires are run behind the two uprights 4, so as to make all the wiring invisible, which adds much in neatness. The terminals for connecting motors and other experimental apparatus are placed upon the little back board D. Old battery binding posts may be used for this purpose. fe) I fe) fe) I fe) C © Cc VR re a ne A board placed on the towel hanger sup- ports of a commode for an instrument board Each terminal is operated by a switch on the board so that it is not necessary to disconnect a wire in order to shut off the Popular Science Monthly current. It is also very convenient to have one of the terminals connected in series with a rheostat E, so that the quantity of — yr 4 +f : OF 4 2 -Sp F® eee All instruments and tools may be kept in the drawers while the top is used for a table current can be regulated. A ground con- nection F might also prove handy for various experiments. A call bell G and small electric light H can also be mounted on the board. For _ anyone possessing a wireless telegraph set, this stand. is doubly convenient, as the 2. aerial switch can be placed on the board — and the instruments mounted directly on the top of the stand, if desired. Innumer- able other connections and uses will readily present themselves, depending on the apparatus possessed. Tools and instruments can be kept in | the drawers I and thus be always handy ~ A small hand vise © can be fastened on the stand if needed. .. The principal advantage of it all is that > everything is conveniently contained in and out of the way. one unit.—J. EDwArD WHITE. Panels Made Out of Rubber Storage - Cells for Radio Apparatus r making panel facings for loose couplers or cabinet sets cut up an old hard rubber storage-battery case and use it for the switch-panel facing. When drilling be care- ful not to apply too much pressure. A plane may be used on this material if great care is taken; but it is very brittle and will break easily. It may be polished with sandpaper. aa ea Sipe? s Commercial System of Wireless Telephony ALTHOUGH it is not generally realized, ‘& Japan has been one of the most iligent countries in making wireless tele- se have developed is unusual in simplicity _ and compactness. It contains no very ei ntricate circuits, nor does it use a delicate air-sealed spark-gap, as in other telephone systems. The few adjustments that are _ necessary can be made by almost anybody, and the spark-gap will work while exposed _ to the air, without deterioration. These _ facts have made the system so practical _ that Japan has already established wireless communication between her important islands by means of it. _ The spark-gap electrodes are made of oxide of iron, brass, aluminum, and similar _ materials which are practically indestruc- _ tible. The electrode surfaces are small and are placed nearly _ touching each other, so that the spark- _ producing potential _ canbecomparatively _ low. Thus, the volt- age of the exciting _ generator is slightly ; more than one hun- dred, though as _ much as five hun- _ dred volts have often _ been used. As soon _ asa potential is pro- duced across the - gap, an oscillating ™ €ircuit that is coupled to the gap _ becomes simultane- _ ously charged. Once _ aspark jumps across _ the gap, the natural - tendency of both the _ inductance and the _ capacity of the oscil- _ lating circuit is to send a current from one _ to the other. The result is that each is rapidly charged and discharged, the current crossing the gap at a rate of about 120,000 times a second, producing one spark with every surging. The surgings in the primary circuit are then induced in the aerial and microphone circuit which is coupled to it. The result is that the aerial radiates its wireless waves, which are modulated by A complete Japanese T-Y-K_ installation Popular Science M onthly 155 talking into the microphone transmitter. But all this depends upon the formation of a first spark which will release the charge of the oscillating circuit. The resistance 2 Aerial Protective resistance AAAAAAAA VVVYVVVV | 5 k = _she ‘gap ret ae & Secondary Generator i Bs ai Microphone Bhullbracce transmitter Choke coil i Ground = Diagram of connections: The transmitting system uses an air- exposed spark gap. A crystal detector system is used for receiving between the two electrodes—caused by the insulating layers of air and of the oxide formed on the electrodes—ordinarily pre- vents this. So an equilibrator is used for temporarily raising the potential in the spark-gap circuit. The equilibrator con- sists of a strong electromagnet which, just as soon as a current begins to build up in it, attracts the armature of a circuit-breaker. The circuit-breaker is sharply opened, and the inductance discharges at high potential, supplying the necessary potential across the spark-gap. Since the equilibrator wore auto- matically, only the simple adjustments of the oscillating circuits require attention. The waves the system sends out, being of relatively low frequency, can be received by the ordinary crystal detector. Using it, a maximum range of thirty to forty miles has been obtained. A Crystal Detector Holder for Wireless Apparatus SIMPLE clip to hold the mineral con- sists of a straight piece of brass sheet- ing with a U-shaped piece of spring brass soldered on at one end. Another and better device for holding the mineral is a reflector from an old tubular flashlight of the larger size. Clean off the enamel and polish up the brass. Fit a piece of wood into the socket and drill a hole in it for a ma- chine screw which passes through into the base of the detector. A large brass washer will be required under the head of the machine screw. Drill and tap out three holes through the side of the cup for the set screws which clamp the mineral. The cup will hold odd-shaped minerals of various sizes and can be turned pround at will. 156 A Trussed Aerial Spreader for Long Wires LIGHT and strong spreader is very desirable when the aerial reaches over 200 ft. in length. While bamboo answers the purpose for spreaders shorter than 6 ft., it does not do for longer ones. = A light frame trussed so that it will be strong enough to hold a large aerial A truss-built spreader fills the conditions admirably. | Select two straight-grained pieces of spruce 9g ft. 3 in. long, by 1 in. square and two braces 6 in. long by 1 in. square. The pieces are assembled as shown in Fig. 1. The detail showing how the braces are fastened to the spreader- piece on the side where the aerial wires are attached is seen in Fig. 2. The other ends of the braces are fastened with wood screws. The rope-bridle is fastened 18 in. from each end, to equalize the strain, as shown in Fig. 3. The arrows denote the line of strain. A spreader built with these dimensions is sufficiently large for an aerial 300 ft. in length.—E. R. THomas. Position of Wireless Waves Passing | Over Land HEN radio waves travel along the surface of the sea, or of any other good conductor, their fronts stand up nearly vertically. When they pass across stretches of poorly-conducting earth, how- ever, the tops tend to gain and the whole wave-front tips forward in the direction of motion. Resulting currents in the surface of the earth cause resistance losses, and the waves rapidly become weaker. This is why it is more difficult to send wireless signals over ground than over salt water. Popular Science Monthly Cloudy Days Best. for Wireless Wave Signals EASUREMENTS made at the Uni- — versity of North Dakota showed — that on the night following a cloudy day — signals were received much more clearly than on nights following days of bright sunlight. It appeared that the cloudiness was most effective when it covered the territory lying between the sending sige _ receiving stations. Improving the Tone of a Test ues" Used on Wireless Detector HE tone of a buzzer used in finding a sensitive spot on the crystal detector can be made high-pitched by inserting a piece of paper, folded four times, between the contact spring and the bar next to the magnet. Also insert a folded piece between the cone of the first coil and the bar. ~ Simple Construction of a Rotary-Gap. Disk N the accompanying illustration is shown a new type of rotary-gap disk which will _ give unusually good results. It is very easy to construct. First procure a piece of y-in. sheet fiber and cut out a disk 9 in. in diameter. With a 4-in. radius draw a circle on this and divide it off into 8 equal FRG AB ANTIANN NY Holes in a fiber disk to allow the spark to jump between the electrodes as it turns parts. Drill holes on these marks slightly larger than the gap-electrodes and drill a hole in the center for the shaft. Mount the disk on a motor in the usual way with a set- screw or clamp, and mount a stationary gap as shown at 4. Every time a hole is passed, the gap is permitted to spark. More holes can be added if desired, depending on the speed of the motor. HE average experimenter’s ‘‘break key”’ consists of a number of springs, _™ contacts, etc., which are attached to : iaie regular transmitting key in a clumsy manner. To send clearly a code with key contacts 14 in. apart is next to impossible. _ With the relay-key described herein it is ible to use the lightest kind of a Morse . for sending, since all the clumsy con- ‘tacts of the breaks -_ magnetic key. Fur- _ ther, no heavy cur- _ rent is handled by the _ small key and thereby arcing and sticking are eliminated. A key as described __ has been in use in my ? amateur station for _ some time and has _ never given any trou- ble in holding the _ detector-adjustment, = even with the most sensitive minerals, such as galena and cerusite. The completed in- ' strument is shown in the illustration. Four spring-contacts are employed, besides the alternating current break. The pair at the right disconnect the detector from the receiver when depressed. One of the contacts at the left shorts the | = oa 7 e Construction of a Magnetic Break Key With it the lightest kind of a Morse key may be used for sending By T. Lambert to the ground through the last mentioned contacts on the key. Some stray current may find its way into the receiver but will not damage either telephones or detector because they are amply protected by the other contacts. There is absolutely no danger of shock as all receiving apparatus is on the grounded side of the oscillation-trans- former. The magnet cores are shown at C. A good grade of soft iron should be used, as it is less liable to hold residual magnet- ism. The cores are threaded to fit the end pieces snugly. The windings can be made directly on the cores after a layer of tape is placed, but it is preferable for ease in winding to turn out two bobbins on a lathe, as shown at D, and wind on them. Use number 20 D. C. C. wire and wind on eight or ten layers, placing a heavy sheet of paper between the layers. On the final layer glue a thin piece of ebonite to give it a finished appearance. The brass crosspiece which holds the screw for adjustment of the tension of the spring E (page 159) is shown at F. The piece G is of hard rubber and sup- telephones while the ports the stationary other one grounds the entire receiver while sending. It will be seen from diagram B that the receiving- tuner’s primary is placed in series in the ground-lead of the oscillation-trans- former. When sending, the high voltage currents from the transmitter pass directly across Four contact springs besides the A. C. break are employed in this magnetic break key primary contact as well as the yoke H for regulating the play of the key. It is attached to the top of the magnets with two machine-screws. The armature support is cut from %-in. brass. The contact and crosspiece holes are best located after it has been set up on its pivot J. This is also of brass, cut to the 157 158 dimensions shown. The easiest way to construct the pivot is to place the arma- ture in the position it will occupy when completed, and then drill a 1/16-in. hole through both pieces and insert a piece of steel rod of that size. The armature itself is shown at K. This is of soft gt fe I amt fie ae ea IE | i ea as O Or ea imcccoe Ox ef ; ; Cate O- i : - 7 a \ "3 Hg pie ran | i ' | j ' Kos po I ye : O re: +H i TPR m O © ii! A—Detail of the break key base giving di- mensions for the locations of the parts iron and can be attached to the armature with one machine-screw. For supporting the contact-springs a hard rubber crosspiece, L, is employed This is attached to the armature by a machine-screw. Holes are drilled in it to receive the machine-screws holding the phosphor-bronze springs, M, in place. A brass yoke is attached to the hard rubber crosspiece G, and holds the setscrew for adjusting the play of the armature. In the large end is drilled a hole of such size as to permit a 14/20 setscrew to pass with- out touching. Four smaller holes in the corners are used for attaching to the rubber piece. A brass strip is bent to the shapes shown at N and supports the contact-screws. These are ordinary 8/32 brass screws. The loop at the upper end of these supports provides an automatic lock nut to prevent the screws from turning when once set. For the contact-pieces 5/16 in. brass rods with dimes soldered on the ends are used. These are shown at O. If one is willing to go to the expense he can have silver plugs made by a jeweler, but in actual practise it will be found that dimes, Popular Science Monthly when filed smooth on the faces, will carry | all the current employed in most stations. The shorter contact has a threaded stud which screws into the armature. The other — one is made adjustable by means of a. — setscrew in the hard rubber crosspiece. A good way to get the dimes together in the — same plane is to set the brass shanks in their proper places and clamp the two dimes between them and then solder. they are in perfect alinement and meet exactly when the key is in use. The various parts are assembled on a> wooden base of the dimensions shown at A. Heavy binding-posts are mounted as shown On: separating the pieces it will be found that — in the drawing of the completed instrument _ and the connections from the moving springs brought down to them by flexible cord. The magnet-leads are brought to the - posts in the rear and the main break- contacts to the side posts. The dotted lines are the locations of the magnets and pivot. _ For setscrews, fillister head brass machine-screws, about 8/32 size may be — used. The connection with the other apparatus is shown in B. The detector in this illustra- tion is shown at D and should be placed as close to the key as possible, since long leads have induced in them currents that are liable to throw the crystal out of adjustment and make the break-in useless. A battery of about ten volts should be used KNAAAANA VVVVVVVY B—tThe receiving tuner’s primary is placed in series in the oscillation-transformer on the magnets. Less would be sufficient but would not give the snappy action so much desired. ws | ‘yo Popular Science Monthly = contacts should be gone over ently with very fine sandpaper, as a or contact is liable to cut down the of the receiver to no small extent. he left contact-screws are adjusted to ouch the springs when the key is depressed while the right hand pair are to make 159 Loading Coil in Series with the Secondary HEN a low resistance detector is used, it is a good plan to tune the secondary circuit by using a comparative- ly small inductance coil and a large con- % Detail of the parts that enter into the = construction of the magnetic break key contact when the armature has come back, - and to break the contact when it has been _ drawn to the magnets. A little experience will make it possible to get an adjustment where there is no a paperking at the contacts and no noise in telephones. __ I doubt if anyone, after using a key such _ as described, will ever willingly go back to _ the old clumsy aerial switch. ae ee An Emergency Form for Winding . Motor Fields _~ QFECENTLY my rotary spark-gap, 110- volt A. C. motor burned out one of f jits fields. As I was ina hurry to use it I tried a quick method of rewinding the coil _by driving a series of nails into a wood _face-plate on a small lathe and winding _ the wire on them. After winding the coil _I bent the nails together so that the coil _ could be slipped off—Epwarp McCvure. = L TY x16] - O | =e TT L O —_ — iy - — vs | (i “ et? 110 ef) Ae 7 & | 7 ab Zé 4 KZ % O -a | coc om | al ane es ge Feel He = FA : 4 rd ri 4 ? O : a Bee: epic i. @ ye if ; | soem by heat 34 Nites nae rf me of #1), OYE ILI 3 d . | M J bee aga of Se ON coor Een | j Soy ae “OD jo} OO ht Ron oe é BET Set -E FE Hi neg Ea ae Pe jee ee Y GLI PLS > ak a : Bios Tas o dim | S4tsits oO O|t ae 2a a H L | 4 denser, for then the current flow is a maxi- iat . T O | mum and the voltage is quite low. For ie high resistance detectors the reverse is K true. Increased efficiency with such de- tectors as the audion can frequently be secured by inserting a loading coil in series with the secondary, and correspondingly reducing the capacity of the tuning con- denser. This applies the highest possible voltage to the grid. — Effect of the Moon and Season on Wireless in the Tropics HILE stationed in the tropics for several years as a wireless operator, I observed that in the periods of a full moon, or thereabouts, the atmospheric interferences are slight and the ether seems to carry the wireless waves with less ab- sorption than when the moon is in its quarter periods, or thereabouts. With a full moon, and using the same receiving set, I could receive from stations that were ~ about 200 miles farther away than those which could be heard when the moon was in its first or last quarter. Also, during the winter months from about the first of December to April, there seemed to be bet- ter atmospheric conditions.#J. M. COHEN. 160 Magnetic Brake for a Wireless Rotary Gap HE radio experimenter who uses a rotary spark gap in connection with his sending apparatus is usually troubled with interference in his receiving set caused Eliminating the interference of inductive noises from the motor of a rotary gap by the inductive noises from the motor of the rotary gap, which if well balanced takes some time to come to a full stop. In the drawing, A represents the blade of a single pole, double throw, switch. The figures B and C are the two jaws of the switch. The figure D represents a rheostat by means of which the length of time nec- essary for the motor to come to a full stop may be regulated. At E and F are the fields and armature of a series-wound motor. The action is as follows: To start the motor, throw the blade A to contact C. When through sending, throw blade to con- tact B, which causes the current from the line to flow to one field through the rheostat D, and results in stopping the motor in two. to three seconds. After the motor has stopped, disengage the switch blade from jaw B, otherwise a waste of current will result—PAavuL J. HOFFMAN. Adjusting the Detector of a Receiving Set HEN the crystal or other detector of a wireless telegraph receiver is ad- justed by the use of an ordinary buzzer set up near the instruments, it is often noted that the point of contact which gave loudest response to the buzzer is not that which is most sensitive for receiving signals from long distances. The most sensitive spots sometimes do not give loud sounds when the local buzzer is operated. This has been noted by many experi- menters who have electrolytic and crystal detectors in use side by side; generally the crystal will give the loudest signal when the Popular Science Monthly buzzer is worked, but the electrolytic 1 prove better for receiving from stations far away. This is because the character of test impulses produced by the ordinz y buzzer is quite different from the radio fre- quency-currents set up in the receiving — aerial by the distant station. In a patent (No. 1,176,925) issued durian $ 1916 to G. W. Pickard, there is shown a — method of avoiding this difficulty. As in- — dicated in the drawing here reproduced, a buzzer having armature A, contact B and magnet C is connected in series with bat- — tery D and test key E. Across the vibrat- — ing contact is shunted a high-frequency - oscillating circuit comprising the condenser — F and the inductance G. This last named ~ element is coupled variably to the sec- ondary H of the receiving oscillation-— transformer, which has the usual tuning detector, blocking condenser, © telephones and potentiometer arranged as’ condenser, shown. The shunt oscillation circuit F, G, is adjusted to produce feebly damped groups of radio frequency-current corre-— sponding to the wavelength most used at the receiver. When the buzzer is put into operation by pressing the key E, there are generated — in the transformer secondary radio fre-— quency-currents corresponding to those re- — ceived in actual radio telegraphic practice. The groups produce tone signals, of the buzzer interruption-frequency, in the tele- phones. The loudness of these signals de- pends upon the coupling between the coil A f Diagram of connections for buzzer exciter which permits accurate setting of the crystal Nh Pe ee rae G and the secondary, and upon the true © sensitiveness of the detector. By selecting the point of crystal which gives loudest responses to such excitation, when the buz- zer coupling is set to produce an intensity corresponding to that of the station which it is desired to receive, the operator may have entire confidence that his detector is properly prepared to do the best work. SON ROD Citi TAINS OTS Se yay lg ag lata aa amie aa an he setae inn > a wee “— il i ile = 2 me Ass “=. Why Edison Succeeded You can’t get on in the world unless you read —read the books which will make you more valuable to those for whom you work. You don’t have to gotocollege. Edison never went to college. But he has probably the finest library of technical books in this country. If you want helpful, practical books on electricity, mechanics, mechanical engineering, wireless, airplanes, sheet metal work, repairing, write to the Popular Science Monthly’s Readers’ Service Bureau. Tell us in what subjects you are interested 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, write to | Popular Science Monthly’s Readers’ Service Bureau 239 Fourth Avenue, New York ci The air pilot lets the bomb sink until it is just below what he gages the depth of the submarine to be. When the airplane passes over the submarine, dragging the bomb on its wire, the air- man gives the bomb a sharp pull upward. It strikes the hull of the submarine and explodes & — rr rr rr rr 162 Popular Science Monthly — 239 Fourth Avenue, New York City August, 1917 $1.50 Annually A new method JN the airplane the elusive submarine has a deadly enemy. Flying high above the surface of the ocean, an air- Py lane can see a submarine which has dived to avoid surface boats. The airplane’s methods of attack have : ot been so un- erring as the gun fire from the boats. But _ now. comes Thomas E. Like, the son of ‘ the distinguished inventor of the Lake-type _ submarine, with a new method of airplane _ attack which looks as though the clearing _ of waters infested by submarines will be : BD orapliched with far more ease in the _ future than it has been in the past. Instead of using high airplanes to drop tiric-bofabs on the sub- _ marines, Lake has de- vised a slower speed airplane for dragging contact bombs against it. His airplane, which uses a_ distributed wind- lifting - area, is capable of high speed when scouting for sub- marines. But when it _ sights one, this airplane can slow up and can carefully go through its manuevers without losing buoyancy. The sient -day naval airplane cannot do that; so that this marks the first advantage in the Lake method of attack. The next, and even more important ad- vantage of the Lake attack is the manner of bombing... The submarine has little chance of escaping it. The slow-going air- _ plane nears the submarine broadside on. A heavy contact bomb is quickly lowered to the proper depth in the water by a spring-controlled mechanism. This mechanism is an entirely new device which received its inception with the de- velopment of this plan of attack. It is very sensitive, for at the slightest reduction in me) CON Details of the sp: which keeps the c CHAIN-DRIVE FROM ENGINE TO WIND, UP CABLE FRICTION BRAKE the bomb to sink to the proper depth : Drag-Bombing Submarines from Airplanes of airplane attack the tension of the spring, the bomb re- sponds by sinking. It will continue to sink until the added upward thrust on the cable, caused by the water’s pushing against the slanting wire which has just sunk beneath the sea, makes up the tension which has been lost from the spring. Therefore it is highly important to properly tighten this spring. In practice, this would be done by means of a turnbuckle which has been rigorously calibrated by factory tests. The air pilot lets the bemb sink until it is just below what he gages the subma- rine’s depth to be. The bomb thus drags along while the airplane approaches its prey nearer and nearer. Soon the airplane pass- es over the submarine. The wire dragging be- hind hits before long against the submarine hull. The bomb con- tinues on and swings’ toward the hull, the airplane drags it the short distance upward, and the bomb strikes the submarine. The percussion explodes the mine, and blows up the submarine without its having the least chance to endanger the airplane. Even should the bomb miss the submarine, it could be exploded from the airplane. The operator simply releases ‘the brake for an instant, then presses down hard on the brake lever. The jerk will fire the emergency device within the bomb, and if the submarine is anywhere near it, the resulting explosion will disable the sub- marine, at the least. The ordinary method of dropping time-fused bombs on a subma- rine requires nothing short of extraordi- nary skill in aiming and timing the bomb so that its explosion will be effective. That method cannot be one-tenth as effective as this drag-bombing plan. 163 ‘WOODEN BRAKE BLOCKS | BRAKE DRUM : TACT BOMB ring-controlled brake able taut and enables Popular Science Monthly a Oe af Bed " - — is ee ee a © Brown and Dawson Three exposures of the Arctic sun made on the same plate. It travels along the very edge of the horizon, as if just peeping above it day and at sunriset. How the Sun Looks in the Arctic Circles in the Morning, at Noon and at Night ORTH of the Arctic Circle, during certain periods of the year, the sun barely peeps over the horizon. Some days you have to stand on your tip-toes, so to speak, to see it at all. At sunrise, midday, and sunset it appears just above the The sun is shown rising, at noon- “An Army Travels on Its Belly,’’ Said Napoleon—Also on Its Feet, Say Chiropodists F your feet trouble you, you are only about fifty per cent efficient as a fighting man. In the Fourteenth Regiment of the National Guard, in Brooklyn, N. Y., the men must submit themselves to a foot examination. The accompanying illustra- horizon, and re- mains in about the same _ posi- tion. It never climbs high into the heavens as it does in warm countries. It travels around the horizon. The _ illustra- tion shows three exposures of the Arctic sun made on the same plate. The pho- tograph was tak- en December 1, I9I5, at 11:45 A. M., I2 M. and tion shows a number of them undergoing treat- ment at the hands of the 1917 class of the _ School of Chirop- ody of New York. The young grad- uates volunteer- ed their services long before hos- tilities were de- clared. Regular estab- lished undergrad- uate and _ post- graduate medical schools pay but little attention to 12:15 P. M., re- spectively. Nine days after the photograph was taken the sun did not appear above the horizon at all, but re- mained below for five weeks, gradually appearing again in reverse order. Graduates of a school of chiropody applying themselves to the relief of the foot troubles of a Brooklyn regiment foot conditions unless they re- _ quire major sur- gical treatment. Consequently there is a particular need for chiropodists at the present time. Numbers of them will doubtless be engaged for the army. are laid with their con- _ flat strips of celluloid or 2 may ‘be bent lengthwise - swung around inde- Every Hair Where It Belongs _ The device consists of two vulcanized rubber which conform with the shape of the head. These are pivoted to- gether, edge to edge, in such a way that either strip may be pendently of the other. The strips fronting edges along the line where the part is to be made. One is held down to conform with the shape of the head and the other is swung around carrying the free hair with it. Thus the hair is parted. A Combined Ice-Box, Pantry and -Trunk for Automobiles COMBINATION refrigerator, pantry and trunk, which can be made to fit any automobile, has been invented by Ralph S. . Hopkins of Seattle. Hopkins has found this | = ! Popular Science Monthly 13 A Mechanical Hair-Parter. It Places = 7, i - at this hair-parting apparatus. E It accurately outlines a straight part _ onany portion of the scalp, separating the hair easily and quickly with- ~ out dependence upon a mirror. One strip holds the hair down on an imaginary line, while the other sweeps the free hair to one side, making a straight part 165 contrivance, made of iron for his five-passen- ger car, most valuable for automobile trips. The apparatus weighs sixty pounds and is placed on the running board. It takes up the entire space on one side between the front and rear fenders, without detracting noticeably from the car’s appearance. It is fastened in place with four bolts. It is as high as the top of the doors of the motor car. The whole ap- paratus is made of sheet iron, painted to match the car, with the exception of the refrigerator, which is of galvanized iron to prevent it from rusting. Hopkins uses his refrigerator, located at the lower right corner of the picture, for ice and perishables. The refrigerator is di- vided into two sections, the upper which holds the ice, and the lower which carries milk, butter and the like. In the lower compartment on the left side groceries are kept, while in the top section, which extends the whole length of the apparatus, are stored all other necessary articles for long trips, such as clothing, fishing tackle, guns, folding chairs and tables. There Are Five Hundred Indian Languages in the United States EFORE you write the Govern- ment or. the Smithsonian Insti- tution and request it to send you the Indian name for this or that thing, bear in mind that there is no one American Indian language. On the contrary, there are no less than one thousand languages in the two Americas and practically five hundred distinct Indian languages north of Mexico. Thus, it is impos- sible to give the Indian word for any English equivalent. If you do re- The owner of this auto- mobile can stop at any suitable spot, set histable - a and partake of a comfort- |] able meal. from the re- : frigerator on the running- board of the automobile CLOTHING AND BLANKETS _/CO ceive an answer to your in- quiry, the word given is IcETANK probably chosen from the Ati; language of the tribe which once inhabited the particular part of the country from which the#® request comes. Popular Science. Monthly A small Niagara which has been de- veloped indoors as a part of the hy- draulic laboratory It takes a power plant of 500 horse- power (see photo- graph at the right) to make the mini- ature Niagara also commercial forms and sizes of turbines under large energies of water may be studied. The whole ap- paratus is fitted with meas- uring devices so that precise measurements may be made at any point. One engineer who inspected the outfit said, “This is using a river and measuring its effects with a teaspoon,’’ so delicate are the tests applied. In the basement of the school there are eight hun- dred feet of canals supplied from the Charles River Basin. narrowings and junc- tions, so that the flow may be observed under all possible conditions. The outfit includes many pumpsand engines forthe work, aggregating about 500 horsepower, together with compression tanks and all the essentials for a mammoth indoor hy- draulic laboratory. The Largest Indoor Waterfall in the World HIS waterfall is not out of doors, nor is it used for the development of power, but it represents the flowing of one hundred tons of water each minute and en- ergy of more than three hundred_horse- power. It is part of the laboratory equipment at the Massachusetts Institute of Tech- nology, and illustrates how this school teaches by means of commercial quantities under ordinary condi- tions. The water here shown has been lifted to an elevated canal, which the students call ‘‘the big brook,’’ forty feet above the base of the pump, and returns through a great pen- stock ten feet in diame- ter to the outflow canal. The conduct of water under such pressure and city. It Fastens Cord Tighter Than You © Can Tie It PACKAGE tie designed to fasten cord without tying the ends, has been invented by Warren L. Bald, of New York The inventor claims that his tie will fasten a cord tighter than any knot ever devised and will hold the cord more securely than a number of knots. A spring wire takes the place of the ACORDS usual knot. Only two operations are J necessary to tie the cord. The cord is Instead of tying the ends of the cord you simply fasten them in the wire loops. The wire takes the place of the usual knot hooked around the wire loops, and, when a strain is put on these loops, the cord is pulled tighter, the spreading of the wire acting as a lever. The device not only saves the fingers of the person who wraps a large number of packages daily, but with the cord properly se- cured in the wire loops it is impossible for the packages to fall apart. These have turns and . - . “Foiling the Pickpocket and Protect- ing Your Watch VERY simple device to prevent your watch from falling out of your pocket has been invented by ee Anton Nord of New York ecity.. It consists of a case 2 Beeumped from sheet metal _ and lined with soft fabric. $ The case, which is fast- ened securely to the _ pocket, has a notch at the top, which is $ rounded to admit the stem of the watch. _ The stem of the watch _ is pushed down inside of two prongs which Ef _ project slightly above _ the case. _ These prongs require _, some effort to separate them, so that the watch can not fall out or be - easily pulled out by a _ pickpocket, without the owner being immediate- ly aware of it. Spi nae a The watch is held securely in a case which is fastened inside the pocket Testing a Car’s Power to Pull Itself Out When Stuck ETTING stuck in mud, soft sand or snow—the particular circumstances depending on the season of the year—is one of the vicissitudes to be guarded against in Popular Science Monthly Test designed to demonstrate the power of an automobile to pull itself out of mud, soft sand or snow by means of power from its engine and ropes wound around hub drums 167 southern California when motoring off the main highways in the mountains or deserts, as it is sometimes necessary to do there as well as in other sections of the country. To demonstrate the possibilities of an invention to be used when the car is mired, a Los Angeles automobile dealer carried out the test shown in the illus- tration below. The rear end of a car weighing 2,250 pounds and equip- ped with a 24-horse- power engine was lift- ed high above the floor by means of ropes at- tached to the floor beams above and passed around hub drums fixed to the rear wheels. In actual practice the ropes will be led forward to heavy stakes or other ob- jects strong enough to resist the pull. Take Good Care of the Eggs This Year—You Will Need Them HE United States Agriculture has called attention to the fact that carelessness in handling ‘eggs causes an annual loss of over thirteen Department of millions of them. The loss is due to small cracks in the shells. Once an egg Shell is cracked even so slightly that the eye cannot detect it, the delicate, protective, gelatinous coating which Na- ture provides as a lining for it becomes exposed to the attack of germs and mold forms, lessening the keeping quality of the egg. Five per cent of all cold storage eggs, the specialists find, spoil because of these small, scarcely perceptible cracks. Just a little more care in handling the eggs on the farm and in their transit to market and to the con- sumer will greatly lessen this important wastage. Handling a Submarine The success of an attack and the very lives of the crew depend almost entirely upon their ability to act as one man Wheels tontrolling diving rudders VERY submarine has its commander —generally a captain—who acts as the very brains of the ship. No one else can give orders; for so interconnected are all the machines, that the conflicting commands from more than one officer would almost surely result in an accident. Hence every one reports directly to the captain through the second officer in com- mand, who, by the way, is also responsible for the correct operation of everything aon its 'y Hatch Eye-piece =~ On vision : end of |. periscope’ Photos © Press Illus. Serv. Above: The U. S. S. “*K-1.’’ Compressed air has just forced out the water from her huge ballast tanks so that she _ rides awash on the surface f Diving depth At left: Interior of the ‘‘K-1.’’ During an attack, the com- mander stands at the periscope and directs the men at the wheels of the controls Battery of compressed-air buoyancy controls of balance tanks. from the ballast tanks to the torpedoes. In making the attack, the captain mans the periscope in the main operating room, just beneath the conning tower. The lenses and prisms in the periscope tube transmit the images from the sighting-piece above the water down to the periscope eye-piece. When the vessel dives, the decks are first cleared. Then the hatches are sealed down and the oil engines are stopped, in 168 . - under water because the oil engines con- 4 quick succession. Storage batteries are turned on to drive the electric propelling motors. Electric machinery must be used sume precious air and exhaust poisonous gases. Popular Science Monthly 169 A Tell-Tale Light System—First Assist- ant to the Motorcycle Cop T would profit the French General Staff as much to have one of its members an agent of the German Intelligence Bureau as . On the next word from the captain, it would profit water from a motorist, outside is al- bent on speed- lowed to fill ing, to display _ the huge bal- — this tell-tale _ Jast tanks in electric signal _ the central on the front hull. Other of his ma- ballast tanks chine. at the ends The device - of the boat Senha Oe consists of a are partially fg series of col- filled to hold 4 ored lights, _ the ship on five in num- an even keel. ber, arranged This trim- perpendic- ming of the Storage battery current is suf- ularly in a submarine, of ficient to run the system and metal case, - course, can be deli- cately controlled by the buoyancy gages and controls in the operating room. The weight of all this water causes the submarine to sink, but not com- pletely. The hori- zontal rudders at the stern of the ship are used to give the final touches to the dive. The com- mander directs the man at the wheel how far down he ATING ARM wishes to go. By [tMANEN 14 AAT A AMBER watching the depth 40 MILES eee 0101 gages in front of him, the wheelman can so tip the diving rudders that the proper depth can be found immediately and held exactly. It takes but a minute or two to dive. In torpedoing a ship, the entire vessel must be turned to aim the torpedo tubes, which lie parallel with the central axis of the sub- marine, in the bow. The command is given to fire. The gunners in the forward com- partment receive the order through speak- ing tubes or telephones. The torpedo is dis- charged from its tube by compressed air. WHITE LIGHT7 GREEN LIGHT 217025 MILES 16 10 20 MILES. IRE FOR PERMAN- EN og CONNECTIO: BLUE 45 MILES. Details of the mechanism by which the passengers and traffic policemen can be kept informed as to the speed of the car and mecha- nism essen- tially similar to that of a speedo- meter. When the auto- mobile to which this signal is affixed moves at a rate of less than ten miles ‘an hour, no light shows. From ten to fifteen miles an hour is indicated by an amber lamp. At fifteen the next higher lamp in. the tier—a blue one— flashes . on. At twenty comesa green light, at twenty-five a clear white light, and at thirty miles an hour or more a red signal shows. Never more than one lamp is lit at any given time, except in the case of a car which has exceeded thirty-five miles an hour. At this point the red light short-circuits, and stays burning even though the car slackens speed or stops. Ifacar, therefore, shows a red light and a green light at the same time, it means that the car has been going at a rate higher than thirty-five miles an hour, and is traveling at about twenty. also to operate a tonneau ex- tension of the colored lights LIGHT MILES LIGHT Bayonet Practice for Our Recruits Above: Marines practicing with the bayonet, which is the most effective wea- pon in this war, ex- cept the machine gun At left: Marines dressed for bayonet practice. They wear masks, chest and neck protectors, and padded gloves Ml Photo Central News Two methods of attacking an opponent are shown at left above. The figure is of stuffed straw, held rigidly in position by an iron rod. At right above isa dummy likeness of von Tirpitz. It The British manual of bayonet tactics has been adopted served as a target at Plattsburg. 170 Li Why the Hindenburg Line Seemed So Impregnable Ss Cc Waa nanws French Official Photos . SEAT Rs se The victorious British have unearthed the se- cret of the strength of the Hindenburg line. It lay in concealed forts of solid cement hidden in the most ingenious ways. In the top picture one is seen built so as to seem part of a ruin One fort discovered by the British was built under an old barn. It was covered over with grass and was ertered by means of the ladder and pulley arrangement shown above. It was used as a station for a machine gun During the holiday season Paris shops contain an elaborate assortment of beautiful figures made of fat and sugar. Here a workman is shown pouring a fat and sugar mixture into a mold. There are a number of skillful artists in Paris who do nothing else in times of peace, but make these figures A windmill palace made of chocolate and butter, a combination which is as effective for sculptural purposes as clay. Locomotives, steamships, air- planes, and about every type of building have been represented in chocolate and butter. They often contain equally edible figures of men and animals 172 Above: Making wax flowers is now a full-fledged industry but flowers made from confectioners’ sugar are equally artistic and true to Nature Above: An artist smoothing out the imperfections in a number of sugar statuettes that have just been cast. When polished and varnished the sugar figures can not be told from marble figures. In special designs the sugar must be extremely fine grained to permit of delicate carvings Fat mixed with tallow is run through a grinder to soften it. When in a plastic form it can be kneaded like dough. To prevent it from becoming rancid, citric acid is added to the mixture before molding An automobile made of nuts and sugar—a good example of the confec- tioner’s art. At the pres- ent time Paris bakers and confectioners are making their choicest sweets in the shape of fortresses, cannons, and armored automobiles The Vanishing Chitune? Sweeps iss Paris On account of the modern construc- tion of chimneys in, larger cities the day of the chimney sweep is about over. But occasionally one encounters him even in Paris. Here one is seen preparing to clean a baker’s oven Below: The little chimmey sweep was formerly a familiar sight, and his shrill call “O-o0, O-o! Voici le ramon- eur!’’ (Here is the chimney sweep) was one of the accus- tomed early morn- ing noises of the city With his tight-fit- ting cap pulled down over his head and his soot bag fastened at his side the little gamin begins his work at about three or four o’clock in the morn- ing so that he will have finished and disappeared from sight by .the time folks are astir. An older man, called the “‘patron,”’ accompanies the gamin, making his contracts and over- seeing his work. Where the chimney © is too small for the boy to enter, his “porcupine” brush is lowered into it. Its stiff outstanding bristles scrub the walls mechanically When the sweeping is over the soot is brushed into a bag and carted away. The gamin requires only about ten min- utes to clean out the largest and dirt- iest of chimneys. His patron receives the remuneration, which grows less and less with the progress of time VILL ASLACKER 1 © Amer, Press Assoc. Above: The message that meets the man who comes to Plattsburg, where an offi- cers’ training camp is situ- ated. The let- ters are of white- washed brick against a back- ground of grass “Don’t be a rube. See the world and learn a trade” is the message carried to country and city lad alike by the energetic bluejacket in flat hat and spring-bottom Ba OC U8¢6 T 9 Photos © Int. Fiim Serv. They sing on ship and they sing on land WLIST.UUL THA HOMOR-MO VV tf At left: James White, first class fireman of the Virginia, aids recruiting by go- ing through his strong-man stunts in Bos- ton. Two lines of men are try- ing to break his hand grasp here Drawing an automobile through the street with his teeth, White proves that he is the champion strong man of the Navy. He likes nothing better than de- monstrating his prowess before prospective navy recruits One way of making a question so effective —when there’s recruiting to be done— it can not be ignored. “I am one half. of good fellowship and exciting times 175 Will you be the other?’”’ reads the placard 7 rr 8 ati Bott tet et ae AW, ae 3 1 Agasns — es ~~ suutauene Remnant ide Bee ARES BRR AER be wemait paene at \ fet SA << Working on a deck mat. These mats are at every door of a battleship, Heavy wire is used for the base. One-inch Manila rope is twisted and woven in and out. When finished the mat has an elaborate rope edge Photos © Int. Film Serv. ————— SOON CHT SA Every battleship has several collision mats, Starting the work on a collision mat by to be used in emergencies. The mats are sewing the first layer of hemp on the canvas, usually thirty feet by nineteen feet. They When the mat is complete it is covered with are made of heaviest canvas and hemp a thick layer of hemp and no canvas is visible 176 as the Seamstress with Nesdle and Thread The strings which sup- port a hammock are called clews when ar- ranged in the approv- ed fashion. The sailors shown above can each make fifty-five clews a day. This work requires little skill and it is one of the first jobs taught to the recruits. The best and strongest of rope is essential. Hammocks serve as beds aboard ship Old pieces of rope are used to form the in- side of the bumper, as shown at the left. One man can make eleven bumpers a day. Atrightis shown the completed bumper. This is the work of a skilled expert Photos © Int. Film Serv. The man in the oval is putting the finishing touches on an extra- size bumper and_ pad- ding it out. All ships are provided with bumpers, which are hung alongside to pro- tect the hull against scratches and cuts and to breakthe force of the jar should the vessel comein contact with an- other vessel or with the sides of the pier or dock In the wave of patriotic fervor which is sweeping over the entire United States, the daily manufacture of flags and patri- otic emblems of every description has run up into many millions Above is shown a motor-driven cut- ting machine in operation on ma- terial for the blue fields of the flags. These blue fields are cut in bulk, many hun- dreds of them at a single cutting. It is difficult to esti- mate the number of yards of bunting that have been cut up into flags since the United States announced her in- tention of joining the contestants in the great war In spite of the fact that electrical ma- chinery of every available type is used, the produc- tion scarcely keeps pace with the de- mand, At © left is shown the form used in cutting out Stars of all sizes Photos © Brown and Dawson As soon as the stars have been cut out they are pinned or pasted on the- blue fields and then passed on to the operators of the electrically . driven sewing machines. These seamstresses turn out an in- credible amount of work in a day At left: Thestars being cut in a punch press. At each op- eration the _ steel die cuts through forty-eight folds of the white bunting, making forty-eight stars—enough for one complete flag— at one time. There are dies of all sizes of stars and eagles Task of Meeting the Demand for “Old Glory” The stripes are cut alternately, first red and then white, at a surprising rate of speed.. Then another battery of workers sew the red and white stripes together. Big flags and little flags, of silk, felt or bunting, all are cut in the same way 179 The sewing on the very fine flags is done by hand, but it must be made especially strong, so that the flags wilf be able to with- stand the flapping of the wind, whichis no respecter of fine materials or deli- cate needlework In center: For spe- cial designs, stencils are made by means of a perforating machine. A black powder is applied over these stencils to mark the design on the cloth. Then artists bring the de- sign into relief with oil paint and brush The machines used for the stitching are threaded with great spools of cot- ton containing twenty-four thou- sand yards each. This is fed in with lightning swiftness and the sewing is done with never a “drop” stitch Waterspout—the Sailor’s Dread for Centuries eo] } SEED A « 8 pment Prere pueue puouwr pLexe puene pmeu puone pumowuse pueease p™meOre pumend puerxs pumene 0 ry bye ue pmewe preue paces paoes pmews puene pmere puete pucre pmo te » > s pweous pueee puere paene pee ue omm- L@re s ° Yr] ; F 4 f ie qi | 4 g a ‘| # ‘ 2 4 é ia! f i 4 || : , iy 2a a ‘ , ; , a 4 5 4 4 r a i Waterspouts have always been the dread of sailing-ship captains. In the Mediterranean, " where the waterspout shown above was photographed on a January afternoon, the ocean q is oftentimes lashed into foam by a series of the most violent spouts. As the photograph 4 shows, the waterspout appears as a conical mass of cloud with concave sides rising from , the water surface to meet an inverted cone of cloud. The phenomenon started as a whirl- wind over the sea during the prevalence of a humid atmosphere. The rise of heated air Z is accompanied by inrushing wind, which literally churns up the water into waves, and , the water and foam are sucked upwards. Fish and frogs have been carried inland by waterspouts. From this fact the expression “Raining bullfrogs” probably originated 7 ‘ J So cir preNe pAGAS Be N SREGEr 4 Ce ERE LG 8 GRRE 8 x eos A puene puons Soe eee — 180 In one of the large theaters of New York, where animals are used in the show, it has been found necessary to build sub- terranean cages in which the air is kept cooled by air blown by electric fans over huge cakes of ice in front of the cages The elephant prefers an internal shower bath. The simplest way to cool him off is to squirt cold water down his throat through a good-sized fire hose. He will hold his mouth wide open for the purpose and squeal with de- light from the effects of it Photos © Amer. Press Assoc. Polar bears suffer even more than their brown brothers from the summer heat. The keepers of the Bronx Park ‘‘Zoo,”’ in New York city, spray the ani- mals daily.. The bears will pose like statues on a ledge of rock while the hose is played on them. The cubs are given ice water to drink through nursing bottles Soldiers’ Art Exhibit at Leblanc’s Museum, Paris , % ; -. q ; ] The period of convalescence of the wounded soldiers is enlivened by much penknife i and construction of toys, which are usually models of devices usedin the war. Here isa Ger- man soldier’s conception of an aerial bomb thrower é—. —_— an goa ~~ a eR: ie French Official Photos The photograph above is a model machine gun mounted on a platform intended to resemble the deck of a boat At left: A statuette of a German prisoner, made by a Frenchman. He is supposed to be securely tied to the stake At right: A figure throwing hand- grenades. He is equipped with all the necessities for hand-to-hand fighting 182 President Wilson’s Message Reaches the Germans mat tic Heathen, vorkaan.s we migueay siebuagen but tr Regitang in Wien Mede des Brafidenten Wilfon gehatten am,2. April 1917 im Kongres yn Wajhingten, ricg cin ney, weil wir offeahaelidy war weed wir ferme anderen Rete gu vericivigen.” We wire SHaren over Radteif yazufigen, ‘Raffen in ver Hand uns ciner unver- eqenftellen maffen, tines Regicrang , em te: MenfHliGieit unr res fen ba: unv nen gieltoe ame ri ct i mids co new cinmal fagen, “oruri@en Bolfee. unt wi : “Inige Dieverbernclluny Ma | ‘gu oenferer Sciren { ig dem eeutithen Bell. ; : i ‘Qed vod ane unferem "Saft im ifm baben * RMonate Sneurds Die deutfthe Regiccung hat ce viche gewagt, cent dewtfdjen Bolle oem volitamviges Qeit ter Rede wnictes Bratioenten Wilfow ‘en unmbgliq 46: vom 2. April 1947 mituutciien. Wir renfea, raf oas veutfdye Bolt, reffem Felten unter rrefea mewen Rriege AG ind Ungedeure | Reigerm wernen, cia unbeftreitharcs Recht bat, yu erfagres, maram die frievlichbrare umd teat deutftdew Self jo yugetaee Republif j ter Reretnig ten Staaten vow ‘Amerita in ten Mriegsyuftand gegen vie ceutide Regkerumg cingetreten HM Deswegen haben rele vie off ; = Sam # tdetcen ubserfegt Wit cer gutigrn Bribie vee cerbanreten Blieaer | Fs ie le uid Dene pratithen Relfe sufounmen aclafienen pee fix ten Conn rer Urflacing dochit widtiges Jiriten “abcn babe, Die Merattion per New YDort Werks. aicurtigen Sergelvts heats penta rwar cia: pemi fe b conten, tetiwitriin, Dae neve Berfabeom aber lie pede 4 ‘ Patten Be te Ht wie ° » | Afagar, the Soacsfey, thee Vatiay tty Bestimoe~ tne” “ pop-gun sham- battle between two wounded soldiers enlivens a dull hour in a British hospital. The toy cannons operate on the same principle as the pop-gun. One of the soldiers has suffered the loss of an eye; the other, a leg Wounded British soldiers listening to a musical comedy performance through an electro- phone service con- tributed by public- spirited people of London to the hos- pitals of that city. Even the baby ele- phant mascot seems to be enjoying the performance 184 Photos © Although the spongy wood of the silk-cotton tree, found principally in Jamaica, West Indies, is too light to be of commercial value, the natives make canoes out of it and fill pillows and cushions with its long silky threads. Brown and Dawson Its root-formations make the tree earthquake - proof ‘| 4 i if 4 1 dh 1H Bamboo belongs to the grass family, although its tall stalks resemble saplings. As material for rafts, fishing poles and even for houses it has been in use since the world was young. Orientals consider the young shoots, which resemble asparagus, a nutritious fcod 185 The banyan tree, on account of its habit of putting forth numberless trunks to support its branches, thus crowding out all other trees, is regarded as a robber and murderer. But it yields rubber equal to Para—and once, centuries ago, it sheltered a Buddha The Automobilist’s Mechanical Cost Keeper It tells the mileage of the car, the life of each tire, and the gasoline and oil consumption 4 : , . of the automobile owner who desires to keep a complete record of his car operation is an instrument on which can be read at will the car r NHE latest device for the convenience the fuel tank or oil into the engine crank- case. | As shown in the accompanying illustra- tions, the thirteen odometers, nested within a casing on the oppo- speed, the trip mile- age, the total mile- age, the mileage of each of the four tires in use, the two spare tires usually carried, the gasoline and oil consumption and warnings at 500 and 1,000 miles of run- _ning to indicate that — adjustments, greas- ings, etc., are neces- sary. These thirteen records can be read as desired. The device is no larger than the ordi- nary speedometer and is mounted on the dashboard in the =m Multometer ft site ends of parallel shafts, are covered by a_ ring-dial, around the circum-~ ference of which are divisions for each of the thirteen records. In the dial face is a slot in back of which the various odom- eters are moved ac- cording to the record desired. Those odometers to the right of the nest, as shown, are slid over to the left on their shafts by means of turning screws on the face of the in- strument so that the ‘ The device con- sists of thirteen “i separate odome- <4 ters, operated in i sequence by a series of spring- pawls in a casing surrounded by a ring dial having thirteen parti- tions for records Turn screws H-w the mileage of tire No. 4 is recorded on the instrument conventional manner. It is driven by means of one flexible cable to the front wheel or to the engine propeller shaft, as desired, and consists of thirteen separate odometers, operated in sequence by a series of spring-pawls. All of the readings are obtained from the mechanical operation of the odometers and of the driving means, with the exception of the gasoline and oil records, which are manually operated and must be set each time gasoline is put into Meccas eT *v~--.. This Odometer slid to Dial __sJeft_to register ge with slots in face Turning screws slide the odometers from right to left on their shafts figures register properly behind the slots in the dial, the latter being turned in the same operation. When a new vehicle is purchased and the device attached, all odometers are set at zero. The speed in miles per hour, the trip and total mileage are registered in the usual manner; one odometer serves to give the same reading on each of the four tires fitted. If tire No. I was removed at 1,000 miles, the face of the dial would be 186 rned until this reading showed through the slots. Then by turning the knob shown _ on thecasing, this odometer would be thrown out of engage- : and the _ odometer for the new tire, No. 5, engaged. If this tire ran’ 1,000 miles before re- 2 moval, the < odometer for tires 2, 3, and 4 would ‘each reg- ister 2,000 miles at that time. As tire No. 6 was ‘put on in place of No. 5, these tmileages would be automatically added to until the tires were taken off, at which time the respective odometers would tegister accurately the mileage covered. __. The miles per gallon of gasoline or miles _ per quart of lubricating oil are obtained by pencil and paper calculation. a i ia vay RO na aiianalie: Inflate Your Tires to Full Pressure, Even in Hottest Weather OOK out! Don’t inflate that tire to full pressure on a hot day like _ this,” is the costliest warning ever hurled at motorists. Instead of saving tires and money it has cost automobile - owners millions of dollars. True, a tire does expand in hot weather, but so slightly as to be negligi- ble in its effect. It never expands to. the danger point. Furthermore, in- ternal heat does not result from the tem- perature of the outside air, but from the con- stant bending of the tire as it travels along. Con- sequently, when you run your tires under-inflated in’ hot weather to combat air expansion, you cause in- creased bending of your tires, and thus create more heat—which is just the condition to avoid. The , Popular Science Monthly The wall§ of the circular garage are eight feet eight inches high and are reinforced with wire mesh 187 A Circular Garage for the Farm, Built from Silo Forms ILO forms previously used on a Mis- souri farm were employed to build the novel circular concrete garage shown in the accompany- ing illustration. It cost about one hundred and fif- ty dollars and is sixteen feet in diameter, with sufficient space on each side of the car for work bench and vise. It is entirely of concrete except for the two-part wood doors and window sash. The walls are four inches thick, reinforced with wire netting. The floor and the roof are also of concrete, the latter with a three inch slope to the foot. Use Your Natural Arm If You Would Be a Good Craftsman 3 Bopras brachiometer (don’t be frightened at the name) is an instrument which has been devised by Professor H. Franklin Jones, of the University of South Dakota, todetermine whether an individual i is naturally right or left handed. Ev ery person is born with a major anda minor arm, and Professor Jones, through study. of this fact, has discovered things about the man who is jack of all trades and master of none. To determine ‘‘hand- edness’’ he measures the bones of the arm with his brachiometer. If you were born with a left major but adopted the right, the fact will be shown by measurement of the re- laxed forearm circumfer- ence, contracted forearm, relaxed biceps and con- tracted biceps. To become thing to guard against is under-inflation. The measuring .device for de- termining whether a person is right or left handed naturally master of your trade you must use your major arm. Roadtown—The Commuters’ Utopia Vitalizing the country with arteries ‘of energy and life from the city By Max Fleischer devoted half a life-time to housing problems, has conceived Roadtown, which, if carried out, should give us all the advantages of the country with none of its disadvantages. The Roadtown plan of housing may be compared with the modern skyscraper hotel or office building. The vast number of tenants occupying these buildings, closely alined for economic dis- tribution of light, heat, power, vertical transportation, etc., by means which are self-contained within the structure, make it possible to rent an elegantly appointed room or modern office at a very moderate figure. But is it necessary to go up into the clouds against gravity to minimize the operating cost? To see Roadtown through the eyes of the inventor, imagine a hotel skyscraper miles in height, as many miles as you dare imagine. Try five hundred miles at least. Have it fully equipped with every conceiv- able modern convenience, complete in every detail. Now, carefully lay this build- ing on its side until it reaches far across the country. This is Roadtown—a continuous unbroken line of Mi EDGAR CHAMBLESS, who has One may live a hundred miles from his office in the city and commute; for distance along Roadtown should be calcu- lated by time rather than by miles, since it is planned to have, in addition to local service, express trains traveling at terrific speed (over 200 miles per hour is not an impossibility with the Boyes Monorail), and as silently as the skyscraper elevator in its vertical plunge. Rows of screened windows under the porches of the houses will ventilate the subway. | Referring to the illustration, it will be noted that each house will have two private front gardens, one on either side. There will be no rears to these houses— nothing erected to obstruct light and venti- lation. Each house will be twenty-one feet wide by twenty feet deep and contain seven good-sized rooms. The walls, floors and ceilings will be of cement and sound- proof. subways and to the continuous roof, which will be a roadway for pedestrians, skaters and light, rubber-tired vehicles. illuminated at night with electric lights. ‘A covered promenade in the center of the roof Stairways will give access to the It will be two-story rein- forced con- crete residences reaching hun- dreds of miles out into the open country. What were the elevators in the skyscraper are now the Road- town subways running in a trench under the building. The lighting, heating and dis- tribution prob- lems for these residences on the farm now solve them- In such a building it seems celves for you. Food kept cold in. Food in containers kept hot) during transit in this this compartment compartment. Cover Q Double wall containing hot water, “Hot water Double ew = inlet containin Chilled water chilled water inlet Trip key The automatic carriers which deliver meals already pre- pared from the community kitchen to the consumer’s home heating-plants, will pro- tect the pedes- trians from rain. In the winter, it willbe steam-heated, enclosed with glass _ panels. The promenade will thus becon- verted ‘into a continuous sun parlor. At in- tervals, towers will be erected which will be used as_ social and shopping centersand con- tain schools, public service stations, libraries, theaters, telephone centrals, etc. possible to live in the country—with The distance between these towers will be every city convenience. 188 determined principally by the operative { Popular Science Monthly eae EE eo. nw sear _ : sot oP oh Cbs) aes RS om Ek. Sind Se, erstcassiioa Imagine a skyscraper hotel. miles in height—say five hundred miles—and fully equipped with every modern convenience. Now lay this skyscraper carefully on its side on the ground, so that its elevators will be subways running in a trench under the building which will extend, ina straight line or in serpentine coils, miles out into the open country. efficiency of the public utilities contained therein. ; _ Being operated on the plan of an im- mense hotel, individual kitchens will not be necessary—the Roadtown kitchen near- est you will take your telephone order, and by means of automatic carriers running on a horizontal track, deliver your favorite - dish right into your dining-room. These carriers will be arranged to preserve the heat in the food during transit, one section of the carrier remaining chilled for cold dishes. The meal finished, the carriers will be returned to the community dish- washer. The carriers will run along a single track and will be automatically switched to its proper recipient by a trip-key, similar This is Roadtown in action to the type-distributing feature of the Linotype machine. Evidently, to make doubly certain that our new ‘“‘city farmer’? will have every advantage of civilization, the inventor of Roadtown proposes to instal a number of utilities some of which are at present avail- able only to the rich. For a better idea of this intention, it may be well to describe briefly those at present under consideration. The temperature of each room will be automatically regulated to suit its particu- lar occupant, by the use of the thermostat attached to the steam radiators. In very hot weather the refrigerating plants will pump cooled water through the radiators. Running distilled water, cooled to a health- 190 ful temperature, will be used for drinking. Heavy doors and windows will be moved automatically by compressed air. Gas dis- infecting pipes will lead to each residence. Vacuum cleaners will be installed. Bell announcers will signal a few moments in advance the arrival of a train ; to the nearest station, allowing sufficient time for the resident to be on the platform. This signal device can be made inoperative at will. The dictograph will en- tertain, lecture, sing or play for you when you do not care to go out. By simply tele- phoning central the name of your favorite selection, the entertainment will be wired to your room or to the room of a convalescent patient. To the practical-minded man the Roadtown propo- sition may now begin to assume the thinness of a fantastic dream, too good to be true. But, is it? The society recently or- ganized to further the in- terest in Roadtown is re- ceiving the cooperation of architects, engineers, builders and scientists. Among them are level-headed thinkers who are not readily bowled over by a fas- cinating but impractical venture, such men, for instance, as Mr. Boyes, inventor of the monorail, M. K. Turner, inventor of the dictograph, and Thomas A. Edison, electrical wizard, who has donated his cement-pouring patents to the Roadtown Society. Estimates, costs and statistics are being rapidly compiled, and in view of the ex- treme economy of build- ing in a continuous line, utilizing one mold for hun- dreds of buildings, of pur- chasing building material in wholesale quantities, and the economy of close alinement, it has been es- timated that one of these seven-rooms and _ bath Roadtown residences could be rented for twenty- one dollars per month. neck, It is The spur strikes the horse’s rein within easy reach Flexible strip The self-opening device is glued to the neck of the bottle. rolls over to form 4 thumb-loop Popular Science Monthly A New Spur Is Carried on the Reins— Not on the Heel iz you dig a horse in the ribs with nicely sharpened spurs, heruns. You naturally assume that if you dig him in the back in like manner, the result will be the same. Herein lies the reason for the rein spurs invented by B. E. Jordan, of Hugo, Okla. The spur consists of a circular piece of steel which is at- tached to metal plates that hold it in position on the rein. The sharp points on the edge of the disk complete the spur. If -it is sufficiently sharp the driver need only drop it gently on the horse’s neck and, as the inventor says, “he will be goaded into activity.”” The prin- cipal advantage which the rein-spur has over the heel- spur is recognized when the rider has occasion to dismount and walk awhile. attached to the << sqeeeeCT TOOT TTT A Bottle Opener Which Will Not Break the Cork N opening a bottle with the ordinary corkscrew, it often happens that the cork | is broken and difficulty is found in removing it without dropping crumbs of cork into the contents of the bottle, or of pushing the broken cork itself down into the bottle. In the illustration below a device is shown which eliminates all the bother con- nected with the opening of the bottle. It is in the form of a loop glued to the top and around the sides of the neck of the bot- tle, by means of which stopper, seals and labels may be removed. Advertising surface of flap It Protect Yourself Against Highwaymen with an Electrified Cane TTACKED by a Flash light prowler, springing at Spparatus. Ng you in the dark, how would Becats =| has solved the problem by one cell connects an electric cane which would paralyze the muscles of the assailant in a_ twinkling. | The cane is loaded with a | high tension shocking coil = = andelectric batteries. These | shocking coil =~ you defend yourself? One young American believes he with flash light both cells withcoil add weight to the cane so that you can wield it with effect, and—what is still more important—prevent your assailant from pinning the cane down so you can- not useit. Press a button— and you electrify the cane cong peice and give him a shock which cane with its Causes him to drop the cane shocking coil immediately. The electric coil is merely an unusually powerful medical coil of an elongated type. It fits into the hollow of the lower end of the cane with the two dry cells that are con- nected with it. The “busi- ness” end of the shocking coil is led to the metal plating which covers the entire lower half of the cane. While the shock from the cane will never kill a man, it will sur- prise him enough to _ throw him off his guard and upset his plans. The cane is further equipped with a flash- light set inits knob. One cell is used to operate -it. The upper end of the cane, carrying the electric bulb and this cell, .can be de- tached and used as an ordinary portable flashlight. Such efficiency in a cane makes it a good companion on a trip through the woods ‘or in the summer camp. Although it was originally intended for protection against human prowlers it is equally successful against four-footed _ ones, even the largest of them. Popular Science M onthly 191 The lower end of the cane is metal-plated so as to be electri- fied by the high tension coil inside The folding crib in use in the automobile. When no longer needed it folds up into compact form A Folding Crib in the Automobile and Summer Camp HAT shall be done with the baby when the family decides to go automobil- ing? The question is answered by a new crib which can be carried in the car and which can fold into a very small space and in such a shape that it can be disposed of readily when not needed. The crib is very com- pact. It can be carried edgewise on the back of the rear seat against the back wall of the automo- bile top, and it does not protrude or interfere in any way with the occupants of the tonneau. Or it can stand on end by the robe rail without inconvenience. In use the crib occupies the space between seats, and gives the baby considerably more free- dom of action and comfort than if he were held continually on the lap of an adult. In camp, the crib is set up as at home. The Time Fuse and How It Works The number of feet, yards or miles which the projectile is to travel can be accurately gaged by simply turning the time ring TIME PELLET SCREW_ PLUG at FOR By Reginald Trautschold, M.E. TIME PELLET STIRRUP_ SPRING FOR TIME PELLET TIME FUSE NEEDLE FUSE a TONATOR SETSCREW BS gee wig 3 FUSE NEEDLE FLASH HOLE POWDER SHAFT_ POWDER CHANNEL POWDER STICK BOTTOM RING. The time fuse forms the tip of the nose of the projectile. It is in five parts: the body proper, its cap, and the top, bottom and POWDER CHANNEL time rings. Fitted POWDER TRAIN between the cap and the body is a ' time pellet held in place by a. stiff stirrup with bent- over ears and con- taining a detonator of highly explosive . material. Under the time pellet is the fuse needle POWDER STICK” (. FELT GASKET POWDER STICK ROWDER MAGAZINE OU have read in the war dispatches that the “troops advanced under-a curtain of fire.’ What does that mean? Simply that a barrage of bursting shells, hurled over the advancing men into the enemy’s lines, forms a protective screen. In order that this curtain of fire may be a real protection, however, and not a terrible menace, it is absolutely essential that the men who fire the guns should have precise control of the point at which the shrapnel or high-explosive shells are to break. It is easy enough to imagine the demoralization within the advancing lines if the men had to fear bombardment from the rear as well as the enemy’s fire. That danger has been practically elimi- nated by the perfection of the time fuse. By simply adjusting the time ring of the fuse the gunner can predetermine the exact point—be it feet or miles from the muzzle of the gun—at which the projectile is to do its deadly work. Shrapnel, and the even uglier high-explosive shells, may be exploded if desired within a hundred yards from the muzzle of the gun, notwithstand- ing the fact that the projectiles start on their mission of destruction at the rate of BASE PLUG PERCUSSION PELLET - SCREW *PLUG POWDER POCKET BODY TOP RING Peacoat FERRU POWDER cmanee POWDER TRAIN BOTTOM RING DETONATOR SPRING FOWDER CHANNEL TIME RING BODY ety ergs Been ANISM HOLDER STIRRUP SPRING FOR PERCUSSION : PELLET F PER- CUSSION HOLDER © SCREW_PLUG FOR BASE PERCUSSION PELLET TTONATOR FOR PERCUSSION FUSE about 1,350 miles per hour. On the other hand, they may be sent whirling through space for miles. It all depends upon the adjustment of the apple little time ring of the fuse. The time fuse is an ingenious little mechanism which forms the tip of the nose of the projectile. It contains a time pellet and a detonator of highly explosive ma- terial. On leaving the muzzle of the gun, the projectile, traveling at a speed of close to 2,000 feet per second, is literally shot away from the time pellet, the bent-over ears of the stirrup which held it in place are straightened out and the fuse needle is driven forcibly into the detonator. The resulting flash passes through the flash hole in the body and ignites the mealed powder in the powder shaft of the top ring. This ignites the train of powder contained in the circumscribing powder train. From the powder channel in the top ring a similar powder train in the lower ring is ignited: through a connecting hollow black powder stick. From the second powder channel, the flash is transmitted to the powder magazine in the base of the time fuse, 192 CO Popular Science Monthly 193 through connecting sticks of black powder °* cap . ‘ ‘ 2 ¢i,8 in the fuse body. The magazine connects ..- nied E34 onl with the powder pocket at the center of erg N20) Pe ase the base, from which the flash is trans- #3 ——@ ove, eS ~~ mitted to the powder tube in a shrapnel + ate _ or to the corresponding “‘gaine” in “Sree the high-explosive shell, which, oeeyee its in turn, delivers to the main explosive charge of the projectile. The passage of the initial flash from the detonator to the powder pocket in the base of the time fuse is varied in length by adjustment of the time ring, and the length of the powder train which has to be consumed before reaching the top of the powder tube or “gaine’’ controls the instant at which a shrap- nel will ‘break’ or a_ high-explosive shell will be shattered. The adjustment of the time ring simply shortens the passage by establishing short cuts between the powder channels or increasing the distance between points of communication. Should, by any mischance, the time fuse element fail to work, the projectile will then break on coming in contact with a rigid’ object, through the action of the auxiliary detonating element of the device. In the base of the mechanism is a second detonator which is held in place both by a stirrup similar to the one which holds the time pellet behind the cap and the body of the fuse and also by a coiled spring between the holder of the detonator fuse needle and the percussion pellet. On the projec- tile striking a firm Shrapnel with its rain of balls, and high-explosive shells with their burst of jagged shell fragments the flash produced from the contact of the time detonator and the fuse needle must pass. Destructive as is the time fuse when fitted to a projectile which leaves a gun, it is comparatively harmless under ordinary conditions, on account of the rigidity of the stirrup holding the time pellet and of the springs holding the percussion pellet. Filling Up Your Automobile Tank Without Spilling the Gasoline 4, VERY autoist will appreciate this funnel, invented by Walter W. Er- rington of Texas. It is an ordinary funnel soldered to a plug which fits snugly in the tank opening. The air valve, through which the air in the tank escapes when the gasoline is poured in is attached to this plug, the valve stem and spring serving as the funnel handle. When the gasoline reaches the mouth of the spout, you simply release your pressure on the spring to let it close the valve. Immediately the flow of “‘gas’’ into the tank is stopped because of the air pressure. So you fill up the funnel and then reopen the air valve. All this can. be done in about twenty seconds. object, the percus- sion pellet with its detonator is thrown violently forward against the de- tonator fuse needle and the resulting flash is transmitted immediately to the powder tube or to the ‘“‘gaine,’’ as the case may be,—thus avoiding the circum- scribing powder With this funnel the autoist can fill the tank of his automobile with gasoline in less than half a minute trains through which And Still the Inventors Continue to Provide Us > Se i This ideal sight-seeing automobile is surrounded by glass, even at the top. City skyscrapers and country mountains can be seen with ease by every passenger This bracket serves the double purpose of holding the license plate and locking the crank handle Two detachable strap-carriers which hold the luggage on the automobile running board Popular Science Monthly A dividend-paying ad- Dirt and grease splashed vertising attachment. It under your mud-guard can be very easily re- Gripping- and compres- also prevents dust and moved by detaching this sing-tongs for making bat- mud from splashing into lining and washing it tery-plate handling easy the faces of passers-by : 194 with Automobile Improvements and Accessories An auxiliary spark chamber which in- tensifies a weak ig- nition by firing the cylinder spark on static electricity VARELOLVARMES CALEEREALGLL pho ALATA AGUA CARAS A veritable tion-hook.”’ afford traction “trac- The stubs will sink to solid ground and in the deepest mud The hot water from the engine can be very effect- ively cooled by this radi- ator made of water-coils Above: The steering wheel is pivoted at the upper section. You can swing it down and enter (a =e | ESAN DIEGO B | / A fully equipped tool cab- inet built in the door near the driver’s seat is always ready for an emergency This overgrown automobile on car wheels is the salvation of short-line rail- roads. 195 Gasoline will here do the work of steam at a fraction of the expense ; ) The Misunderstood Shark Under-sea photography is adding to our scant knowledge of these wolves of the deep A shark weighing 800 pounds and more than twelve feet long, caught by Mrs. Otto Jaeger at Palm Beach. It was caught with a rod and reel but had to be shot with a heavy caliber rifle for the attacks off New Jersey. Sailors will tell you that sharks will eat anything; ILL a shark attack a man? ‘‘Yes,” \ \/ say the landlubbers, some of whom saw sharks deliberately attack and kill bathers along the New Jersey coast last -year. ‘No,’ indignantly retort the sea captains, fishermen and_ shark-wise scientists. The truth is that only a few facts about sharks are well established, apart from the question of whether they do or do not kill human beings. For instance, there are so many different kinds of sharks that it would take this page, set in fine type, to list them. When it reaches a length of three feet the dog fish becomes a shark to most people. Yet the white or man- eating shark attains a length of forty feet. There are sand sharks, nurse sharks, blue sharks and others too numerous to mention. But the fact that the white shark has the designation “man-eating shark’”’ is evidence enough that he is an eater of human flesh. His triangular teeth, his armor-like skin and his lightning speed under water make him a wolf of the deep. His home is in tropical waters, but he is an occasional visitor to the waters of Long Island—and without any invitation, _too. The white shark has been blamed that they are shy and cow- ardly; that they are inactive in the daytime and feed mostly at night; that the hungrier they are the more ferocious they become, attack- ing and killing other sharks, and that they are the swiftest swimmers of the deep. There seems to be some misunderstand- ing concerning the way in which sharks attack their victims. Some claim that they turn over as they attack, so as to bite more readily with their receding under- jaw. Others claim that they attack head- on, swimming to their victim in a straight line. According to J. E. Williamson, whose work in photographing the shark under water for the motion-picture plays ‘““Twenty Thousand Leagues under the Sea” and “The Submarine Eye” has been notably successful, the ‘‘head-on’’ description of attack is the correct one. “I can prove by my pictures that a shark does not turn over to bite,” states Mr. Williamson. “If a shark wants to pick up anything from the bottom of the sea he goes right down to it as a cat pounces on a bone and picks it up. A shark does not turn over to bite any more than any other fish does.” In photographing sharks with his sub- marine camera, Mr. Williamson used a steer as bait. The carcass floated on the surface of the water some ten feet from the camera. It did not take long for the 196 Popular Science Monthly sharks to locate it. They approached cautiously at first and then attacked it, striking it with the force of a ram and tearing off huge pieces of flesh. Attached to the body of each shark, as the pictures show, were the usual pilot fish, clinging with the aid of sucker fins. As soon asa shark is dead the pilot fish attack it, eating their way through the dead body. One shark, Mr. Williamson observed, struck a projecting beam and was dazed mo- mentarily. The instant the other sharks saw this they fell upon the unfortunate one and literally tore it to shreds. Ordinarily, sharks are easily caught with bait and hook, and frequently they become enmeshed in fishing nets. But no one has ever devised a scheme whereby they 197 can be caught and killed in large numbers. One ingenious method is here illustrated. On each side of a small patroling vessel are mounted a number of rotary reels each of which carries an insulated electric cable. To the free end of each cable is secured a large fish hook carrying the bait in the form of a fish or piece of meat which is let down over the side of the ship almost to the water’s level. The reel drum has on one of its heads a number of contact pins which are con- nected with the insulated cable. As soon as the reel is turned slightly, one of these pins comes in contact with a stationary bracket connected with one pole of a dynamo supplying a current of 220 volts and five amperes, the other pole being con- One of the scenes photographed un- der-sea by the Wil- liamson Brothers for their thrilling film production, ‘“‘The Submarine Eye.” In this pic- ture Mr. William- son proves that a shark does not turn on its back to at- tack an enemy as is commonly supposed Sharks are easily caught with bait and hook. Here is shown the type of giant hooks used the bottom of the picture. by sucker fins and feeds on the body eventually Notice the small pilot fish underneath the shark at It clings to the shark 198 Popular Science Monthly a ae ee _ ge INSULATED CABLE a el al mm, From dynamo > to ships hull , A A vessel carrying a new device for killing sharks by electricity. The detail of the device by means of which the bait is charged is shown in the lower right-hand corner of the picture nected with the metallic hull of the vessel and the water. When a shark seizes the bait, he pulls on the cable, and the reel is rotated. The electric current then shoots from the dynamo through the cable, the hook, the shark’s body, the water, and the ship’s hull back to the dynamo. The electric shock contracts the shark’s jaws around the hook like the jaws of a vise, so that escape is impossible. He is electrocuted almost instantly. Co-operative Kitchens to Solve the ‘High Cost’? Problems HAT the cost of the primary necessities of life has increased to a point that causes hardship, privation and under- nutrition among the unemployed or in large families striving to exist on a small income, is no doubt pitifully true. In the majority of cases, however, it is expensive tastes and pampered appetites which suffer most. Ignorance of how to spend money in order to get fullest food value and of how to pre- pare the food to the best advantage is also a contributory cause of hardship. The food actually required for the body’s needs costs very little. Enough pork and beans, bread and butter, milk and coffee, with the fuel to cook it, to amply nourish an adult for an entire day would cost only about twelve cents, according to expert dietitians. Numerous other in- expensive and healthful foods there are to add variety; but the problem is to govern the quantity and kinds of food by the needs of the individuals to be served and to prepare it appetizingly. The solution seems to lie in the co- operative kitchen, in which Science writes the menus, consulting not the personal appetites of the patrons but their specific needs. The highest cost of meals for an entire day in such a kitchen should be not more than thirty cents for each in- dividual, including the diagnosis. Popular Science Monthly Teaching the Proper Care of Forests by Object Lesson Models HE right and the wrong way to cut timber is shown by realistic models which the Forest Service has had prepared for exhibition purposes throughout the country. Three models are included in the series. The first shows a stand of one acre of virgin timber, an actual scene in one of the national forests that has been repro- duced on a small scale with great accuracy both as to proportion and coloring. The second of the series shows the same stand after a timber sale conducted in accordance with the regulations, of the Forest Service. The matured trees have been felled and cut into lengths which have been arranged in systematic piles to facili- tate their removal from the forest. All of the brush and small limbs, which, if left on the ground would constitute a fire hazard, have been arranged in compact piles in readiness to be burned under the watchful eyes of foresters. The third of the series shows an example of the wrong way to cut timber. Logs of various lengths are seen scattered about, no attempt having been made to arrange them in piles. Some of the trees felled have not been cut into lengths; many have been cut down without regard to size or maturity. All of the cut timber and the trunks of the standing trees are charted and the condition of the ground indicates that the forest has been burnt over, the inference being that careless methods on the part of those engaged in cutting out the timber have resulted in the spreading of a forest fire which might otherwise have been checked. The Forest Service has two sets of these models. One, which shows a stand of Western yellow . pine, is utilized for the western section of the country; the other, depicting a typical forest scene in the southern Appa- lachian region, for the eastern section. The three mod- els are exhibited in connection with lectures on forest preservation. 1 RRROOE CREE RIRBES SP rn = oe BEFOR™ wegen Ne One of a series of models used by the United States to Forest Service to show how timber should be cut 199 The helmet keeps the wearer alive by draw- ing its supply of fresh air from next to the floor A New Helmet for Use in Smoke or Gas-Filled Chambers HIS is not a gas mask such as is used in European trenches. It is a new helmet which the British Government has installed on five hundred battleships to be used below the decks when entering gas or smoke-filled compartments. It is also being introduced in America, in city fire departments. When used in smoke or gas-filled rooms this new helmet draws its supply of fresh air from next to the floor, taking advantage of the well known natural law that heat, smoke, fumes, etc., rise, leaving a cer- tain amount of ox- ygen close to the floor. The trailing hose of the new helmet seeks that cushion of fresh air next to the floor. The helmet weighs only four pounds. One size is adjustable fit a man, Woman or child. America’s Biggest Flying Machine Glenn Curtiss builds a giant airplane for the Navy By Carl Dientsbach N no craft are the drawbacks of small intoa true “whaleback”’ to become at least | size so manifest as in aircraft. Flying really seaworthy. In its new extreme size in a disturbed atmosphere is never less and shape it promises to supersede that severe than navigating an angry ocean. homely compromise, the “seaplane,” a - moderately enlarged airplane mounted on high stilts on a catamaran ‘‘surfboat.”’ Not infrequently, these stilted floats were broken off by the waves through which they cut better than small aoe flying boats. The smooth, shapely hull of the new flying yacht which Glenn Curtiss has built for our Navy, is one piece with the extremely strongly built planes like the auxil- The alti- tude, the’ indescrib- able emptinessof the air, and the offdrift caused by the wind make it difficult to follow a set course. Yet an airplanemust be humored in gusts even more than the trickiest sailboat. War demands, in addition, the most a oe intricate observations; shells must be dodged, exact aim with bombs and machine guns taken, and rapid maneuvers carried out in aerial combat. Increase the size of the airplane and at one stroke seemingly insur- mountable difficulties are overcome. Exacting duties may be divided among a more numerous crew. Strong celluloid windows protect the men from storm and cold; no ham- pering clothing or goggles are re- quired; there is space to move about; numerous instruments and conveniences can be provided and handled at ease. Airmen have to thank the ocean for all these bless- ings. No mere cockle shell of an airplane can ride the waves as a naval airplane must. The old || oe oe “flying boat” had eventually not |: “i — re only to be vastly enlarged, but also The smooth, shapely hull of the new Curtis flying completely decked over and turned yacht is in one piece with extremely strong planes 200 Popular Science Monthly iary floats on the wing tips, and promises to defy the ocean successfully. The difficulty of making any large air- plane relatively strong enough, although partly overcome because the unobstructed sea is an ideal starting and landing sur- face, still lingers in a certain relative de- ficiency in carrying capacity. On the other hand, there is a most welcome im- provement in equipment and comfort which permits, among other things, a liberal utilization of electric lights. Heavy loads, however, cannot be carried without materially cutting down the radius of action—loads such as heavy gins and ammunition. With motors of 400 aggre- gate horsepower, a span of 92 feet and a total weight of 7,000- 8,000 pounds, this machine is expected to make from 55 to 85 miles an hour. So low a minimum speed is not objectionable on water. With only two men aboard, fuel for five hours might be carried. All rudders and con- trols are worked by elec- tricity, and controlled most of the time, gyroscopically. Teaching | Children Natural History with Animal Pictures Made of Sand HE approved method of teaching very young children is to disguise the instruction under the cloak of amusement. An interesting development in the carrying out of this idea is found in the sand pic- tures of Walter A. Ward, of New York city. Cardboards covered with colored pictures of animals are given to the children to- gether with bottles containing the vari- ously colored sand. The children paint the body of the animals with glue, and then carefully cover the colored portions of the animal bodies with the appropriate colors of sand. In this interesting way, while the chil- dren seem to be merely amusing themselves they are gaining very definite instruction as to the names, coloring and physical characteristics of the different animals. Stories in connection with their habits and the countries where they may be found naturally accompany the pictures and en- large the scope of the work. The rudi- ments of drawing and painting, as well as of Natural History, are indirectly taught in this way. ° ee - ~ ‘7 r j Above: The larvae of the Automeris Io, the moth shown at. the left. Its brilliant stripes and branching spines are its protection Photos © Brown and awson Sometimes an Object Is Beautiful Because It Is So Ugly VERYBODY is familiar with the ex- treme ugliness of the bulldog’s face that makes the animal positively attractive; and everyone who has studied the moths is familiar with the marvelous hideousness —or beauty—of the larva of the Automeris io. The Jo is found from Canada to Florida and westward and southward to Texas and Mexico. In the larval stage it feeds on the leaves of almost any tree or shrub. For ages the enthusiastic lepidopterist has regarded it as a beautiful creature. The dainty green body with lateral stripes of pink and creamy white covered with clusters of branching spines forms an object to be admired—and respected too. It should be handled with care or painful consequences may result. Yet it is a curious fact that in spite of all the pains that Nature has taken to protect this beautiful creature from birds and other large enemies, she has left it open to at- tack from the tiny ichneumon wasp which drives its sting between the spines and there places a parasital egg. In this way multitudes of the larvag are destroyed. 202 How Would You Like to Hold a Chinese Printer’s Job? HINESE characters do not express sounds although the pitch of the voice is significant. Their letters are ideo- graphs, or writings of ideas or things. Hence the Chinese have no alphabet, strictly speaking. For this reason the Chinese must employ an astounding number of characters. It takes about ten thousand characters to print a book in the Chinese language; yet some- times an entire thought “or a whole sentence is represented by one char- acter! The word “black”’ is one character, and so is ‘‘mother,”’ ‘“‘dead,”’ : “ves,” “yellow,” and a great many other words. With such a conglomera- tion, is it any wonder that the American printer won- ders how it is possible to print anything in Chinese? The illustration shows a frame containing one complete font (a font is an assortment of type of one size and style) of seven thousand Chinese characters. It required a month’s time to arrange the type in place. The frame is sixteen feet long and five feet high. pms nor the heavy it can be torn This hood can safely be used through the thickest woods since neither the strong wire netting Popular Science Monthly A Wire Hood for Protection Against Bees or Mosquitoes LL too often, the best fishing and out- ing grounds are to be found where the mosquitoes and the wood pests are thickest. F. L. Rhodes, a fisherman of Michigan, at least found this the rule in his State. Notwithstand- ing the regular hoods of cloth mosquito-netting which he would use, the insects would final- ly get at him; the netting would catch in the bushes. He decided to devise a mosquito-proof hood which would overcome the difficulty. Unlike cloth-net hoods, Rhodes’ protector is made of fine brass wire which will not tear. A piece of non-breakable transparent mica enables the wearer to see, while a slide-covered mouth open- ing is provided toaccommo- date a pipe. To the ends of the wire netting two pieces of durable cloth are attached, the top cloth being used to secure the netting to the hat by means of a string. The bottom cloth of this hood is meant to be tucked under the coat. Such a hood is also useful when robbing bee-hives. cloth beneath by the bushes A frame of Chinese type containing one complete font of approximately seven thousand characters. The frame is sixteen feet long and five feet high. It took a month to distribute the type ; | A Street Cleaner Built Like a Carpet Sweeper Cleaning two hundred thousand square yards of pavement 2 aes motor-driven vacuum street clean- er shown in the accompanying illus- ~ tration is built on exactly the same principle as that of the ordinary household carpet sweeper. It differs from others of a similar type in that every par- — ticle of the dust and dirt picked up is retained in the vehicle storage bin. This is ac- complished by passing the air sucked up with the dust through a water seal. The passage of the dust- laden air through the seal filters it so that when expelled from the apparatus - itis clean and pure just like the outer air after a rain storm. The vehicle is entirely self-contained. It sweeps the street, picks up the dust and dirt, deposits it automatically in its storage bin and can finally run to the point of dis- posal or have its load of sweepings trans- ferred to other vehicles to conserve its own time for the cleaning operation. While the sweeping and picking up ot, he load is entirely automatic, the method em- ployed is very simple. The apparatus con- sists of a conventional motor truck chassis on which are mounted a two-part storage bin, a blower driven by a separate gasoline engine and a header or funnel-shaped pas- sageway by means of which the dirt is sucked up off the ground and transferred to the blower from whence it is forced in the two-part bin. The blower and its direct-connected gas engine are mounted transversely of. the frame directly behind the driver’s seat un- Cleaned-out air to atmosphere The street-cleaner motor truck consists of a two-part bin, a blower, and a funnel shaped passageway through which dirt is sucked in. At left is shown a section of the brush and its nozzle in eight hours der a light metal cover. At the bottom the funnel-shaped header spreads out into a long suction box in close contact with the ground and supported on chains for raising or lowering as required. Air and dirt on the street are sucked through this header into the center of the blower as the latter is revolved. It is thrown out at the peri- phery of the blower into a rectangular pipe leading to the top of the storage bin. The latter is divided into two parts by a_ horizontal partition. As the air enters the top portion it swirls around and deposits the greater portion of the dirt on the bottom of the upper com- partment. The air is then drawn out and carried down into a small bottomless pan with its lower edges below the surface of several inches of water in the lower compart- ment. The partly-cleaned air has to pass down through the water and up on the out- side of the pan before it is led to a pipe open to the atmosphere directly aft of the driver’s seat on the side opposite the blower. The air is thus washed and freed of its dust before it is allowed to escape. The dirt collected is taken out. through doors in each compartment at the rear. This type of cleaner prevents the scat- tering of dust through the air and is cheaper and quicker than the old hand method or the broom and flushing method. It will clean two hundred thousand square yards of pavement in eight hours. Another advantage is that it does not make the streets slippery as does the water flushing. Almost cleanaiv out of top bin Rear door for, Dirty airto wate rseal ~ Dust andair in 203 Above: Grass growing on the wall paper of a New York city apart- ment. At right: How the salad is grown on a rug on the housetop Growing Mustard and Water Cress on Blankets ROFESSOR JASPER JEGGLES, an English botanist, advocates some quick methods of salad raising. ‘‘Mustard and cress,’ he says, ‘“‘can be grown anywhere. All that is required is an old blanket hung over a line and well soaked with water. Sprinkle the mustard Popular § cience M onthly seeds over it. In the steam-heated rooms his crops grew in double quick time. But the janitor stopped him. . “In England one big firm has manu- factured umbrellas of a soft, absorbent ma- terial, so that seeds may be planted on them. Thus people walking along in the rain with their umbrellas covered with short, edible grass, present a refreshing appearance as of moving fields of living green, or floating emerald isles.’’ The professor says this—not the editor of POPULAR SCIENCE Montaty. Is he jesting or is he merely practical? Professor Jeggles is on his way to the Fiji Islands to study the flora and fauna there. He did not leave his address. Children May Write On These Walls With- out Fear of Punish- ment HY would children rather write on im- maculate walls than on writ- ing paper? Because, first, their mothers caution them not to do it, and,- second, because the walls are whiter and the writing looks better on them than it does on paper. But the time has come when the mother need fear for the white nursery walls no longer. They can, in- - deed, be changed from a source of irrita- tion to educational purposes by means of a finish which makes them washable. In other words, all pencil, seed on one half of the blanket and the cress on the other and in two weeks time you will have a crop ready for the table.” In addition to grow- ing salads on his blan- kets and flannels, Pro- fessor Jeggles is report- ed to have engaged in near-mortal combat with the janitor of the apartment house in which he lived. The professor was given to planting seeds on his wallpaper. He damp- ened the walls until the paper was pulpy and then sprinkled the With a finish that makes them wash- able, the walls of the nursery may be used like ordinary blackboards crayon and pen marks may be washed away. Consequently, the wall surface is as good a place for drawing pictures or working examples as the ordi- dinary blackboard. Although the finish is intended primarily for the walls of the . nursery, it may be used in the kitchen, living room, or other part of the house where chil- dren are wont to try out their artistic ability on the walls. The fin- ish may be in any one of a number of differ- ent shades. ; a a 2 ee ae aoe oe ‘Lincoln, a graduate of the Minne- somewhat similar to milling ma- ' from them in that it does its work will do work equivalent Popular Science Monthly Plowing and Pulverizing the Soil in One Operation ROTARY tiller which prepares ‘a seed bed without the usual harrowing, disking and rolling opera- tions has been invented by Guy E. sota Agricultural College. It is chines used in Europe, but it differs on a furrow turned with an ordinary sulky plow, while most of gm: TER EK ses ; : t ‘ 7 ot i aia “ ie ere Seon 3 rs & q : i the foreign machines work on the soil just as it lies in the field. ~The tiller attachment con-. sists of a steel rotor tooth set to the right of the share and mold-board. The rotor is geared at the top to the shaft of a small gasoline motor which whirls it at the rate of five hundred revolu- tions a minute. Thus the teeth of the rotor shred and tear the weeds, grass, roots, The rotary tiller plows and pulverizes the soil, weeds and roots in one operation, eliminating har- rowing, disking and rolling The steel rotor tooth which is set to the right of the share and mold- board. It is geared to the shaft of a gasoline motor fertilizer and soil into a finely pulverized mass, mak- ing a mellow seed bed for the sowing of any crop. For use with the tractor the tiller attachment.can be run by the tractor power. The modern farmer has come to realize that the fertility of the soil depends upon the distribution of a goodly amount of humus (rotted vegetable matter) through- out the entire seed bed. Formerly this humus, as surface litter, was raked up and burned. Today it is returned to the soil to help feed the coming crop. When it is cut up, pulverized and distributed by a milling machine it produces a scientifically perfect seed bed. There is undoubtedly a large place for the rotary tiller in the agri- cultural industry if it COTTON SOAKED IN DISINFECTANT to that of harrows and disks at a cost not much in excess of that in- curred by horse-drawn implements. The prin- cipal drawback to till- ing and milling ma- chines has been the expense involved in their operation and breakages when encountering stones and other obstructions. The tiller described The handle of the brush folds over the bristles and keeps it germ-proof with disinfectant will only have to deal with stones which pass over the mold-board—an important fact in its favor. On the other hand, there would seem to be a waste of power in raising the furrow of soil several inches in the air in order to mill it. Some tillers work on the soil without raising it at all. A Water-Tight Holder and Sterilizer for the Toothbrush HE toothbrush il- lustrated is made with a folding handle, somewhat like that of a familiar type of pocket comb. But the _ tooth- brush handle does more than fold over the bristles of the brush. It forms a receptacle for a disinfectant which will keep the brush perfectly sterilized and an- tiseptically clean until it is ready for use again. When the brush is clamped in its hollow handle it may be carried in the pocket, if mecessary, in perfect safety, without danger of soiling or dampening the pocket. 206 A Two-Million-Dollar Hospital Ship for Our Navy LANS for a hospital ship for the United States Navy have been completed by the naval constructors and officials of the Bureau .of Medicine and Surgery, and work on the new ship, which will be a medel of its kind, will soon begin at the Philadelphia Navy Yard. Congress has allowed $2,350,000 for its construction. Although the exact dimensions of the ship have not been determined, it is known that she is to use oil as fuel and that a special gyroscopic engine will be installed, to reduce pitch and roll to a minimum. The ship will be equipped with the best surgical instruments and paraphernalia known to medical science. The several hospital departments. will consist of an operating room, the out-patient depart- ment, dental operating room and labora- tory, X-ray room, chemical and biological laboratory, several wards for the treat- ment of acute and venereal diseases, and a contagious disease compartment. There will be the usual wards and special accessory rooms for linen, wash rooms, pantries and kitchens. The main opera- ting room will be located amidships, ex- tending the height of two decks and pro- vided with every lighting facility. Special rooms for the examination of eye, ear, nose, throat and kindred ailments will be provided in the out-patient department, where patients may receive the most ex- pert care. One of the important features of the pro- posed ship is the contagious disease com- partment. This will be so designed as to be completely separated from the remainder of the ship and the latest methods of dis- infection will be employed. WARRANT OFFICERS, Popular Science Monthly Lo, the Soya Bean! A Substitute for Meat, Fish and Fats ITH all due respect to Western civil- ization and progress, we must never- theless yield the palm to China for the production of the soya bean, a vegetable - so full of promising possibilities that agri- cultural experimental stations all over the ‘United States are concentrating attention upon it. Milk from soya beans is no longer an experiment but has become a marketable commodity. It is sold in cans as a powder or in liquid form. As a substitute for meat and fish the experimenters say all that is required is the co-operation of good cooks to devise sufficient variety in preparation of the beans. The oil is considered of especial value. It may be used as a substi- tute for linseed oil or may be hardened into an edible fat suitable for cooking or even for table use. The pulp, or what is left over after the oil has been extracted, is con- ceded to be a valuable cattle food. The only difficulty encountered thus far in the experiments with the soya bean has been in finding a suitable solvent to dis- solve out any oil that may be left in the meal before the left-over portion is con- signed to the cattle. Naphtha has been found to be good, but unless care is taken to remove all trace of it from the meal the new fodder loses its value as a cattle food, for the cattle refuse it on account of the smell. Another chemical which has been found to answer the purpose is try-chlor- ethylene. It is not offensive in odor nor poisonous. Yet a dangerous reaction has at times occurred when it has been used as a solvent. MEDICAL OFFICERS' MESS \ROOM PATIENTS AND CONTAGIOUS, MESS AND RECREATION ROOM AUTOPSY ROOM ms |W WOME MEDICAL CORPS” GALLEY, N ~ RECREATION ROOM” NURSES =. PIT ee ry er fll ENT) NES ; a Ae * | mee 33 : ton oon =a To far : g " ‘s Wh ir = Z ‘Dien! sas A, ol BS f° ated we Tiddddddtidtdddddd hdd dda dd add te How the space of the proposed two million-dollar hospital ship for the Navy will be apportioned. The best surgical instruments and equipment known to medical sicence, as well as the latest d 3 J The Mysterious Ice Mines of the United States HERE are several caves in the United States where Nature seems to have become confused as to the seasons. During the late spring and summer ice forms and a freezing temperature prevails, but as winter comes on the interior of the caves becomes milder, the ice gradually melts and a kind of subdued summer sets in under- ground. One of these peculiar caves is to be found at Coudersport, Pa., and one at Decorah, Iowa. The superstitious among the resi- dents of those localities give the caves a wide berth and look with suspicion upon any one daring enough to attempt to in- vestigate them. Edwin S. Balch, of Philadelphia, who has made a study of the subterranedn ice mines, as they are called, states that according to the theory evolved by investigators the - formation of the caverns is such that the cold air of winter does not penetrate and settle in them until late in the spring at the time when the water from spring thaws is seeping through the walls and roof. This water meeting the cold air freezes and stays frozen all summer until, as the fall season approaches, the warm summer air at last finds its way into the cave and melts the ice. ° When the snow is flying above and ice- skating is the amusement of the moment the summer air is at work in the cave and still water bathing might be indulged in by the residents of the community if the environment were right and if they dared. By the time this summer air begins to lose its heat it is spring again above ground. ] OPERATING Popular Science Monthly ; We tetiata 207 Poison Ivy: How to Kill It and Cure a Case of Inflammation HE cheapest and most effective method of eliminating poison ivy, according to experts of the Department of Agriculture, is the simple one of rooting up the plants and destroying them. If the poison ivy is in large fields it may be necessary to plow and cultivate the land. Ivy on large trees, stone walls and buildings can be killed by arsenate of soda, at the rate of two pounds to ten gallons of water. Two or three applications are sufficient. The fall of the year is the safest time to handle poison ivy, because at that time the sap and pollen are out of the plant. With the exercise of due care, the use of overalls and gauntleted gloves will enable most individuals to deal with the plant without danger. A further protection is to grease the hands with lard and after the plants have been handled to wash off the hands with strongly alkaline soap. Minute amounts of a nonvolatile oil in poison ivy is what makes it cause extensive inflammation. Alcohol or a solution of sugar of lead will remove this oil; it is insoluble in water. In cases of poisoning, one of the most effective methods is to cleanse the inflamed surface repeatedly with alcohol, or with a saturated solution of sugar of lead in alcohol, using a fresh bit of lint or absorbent cotton each time to prevent the spread of the irritant. Covering the inflamed parts with lint or absorbent cotton kept constantly moist with limewater or with a saturated solution of bicarbonate of soda will afford relief. It is a curious fact that many people are so constituted as to be able to handle poison ivy without being at all affected by it. APPREMTICES \ CONVALESCENTS L — | methods of disinfection and communication control will be employed on board the ship. The main operating room will be located amidships and will extend the height of two decks 208 How the Government Seals Unofficial Wireless Stations MATEUR and commercial sta- tions alike have been ordered closed. The Government cannot af- ford to take any chances of military in- formation leaking through to the enemy. All aerials have been dismantled, and the in- struments stored away. In the very powerful wireless stations, the further precaution has been taken of sealing the apparatus electrically. The manner of seal- ing such a station is well illustrated in the accompanying photo- graph of New York Popular Science Monthly High-tension wireless transformer A heavy wire short-circuits the high-po- tential sending transformer. If an at- tempt should be made to operate the station, the transformer would burn up lines are spaced by virtue of an evenly notched rack which allows the tablet to be moved away from the elbow rest by the distance of one notch. . An improvement on this tablet has been developed by ArthurE. Tremaine, of Boston. By. using a straight edge and a brass wire placed three-quarters of an inch above it across the paper, the sightless writer is able to keep the size of his letters uniform. Moreover, by eliminat- ing the elbow-pivot principle, each line will be straight and not curved in the are of a circle. Ink as well as pencil can be used since neither the beveled straight-edge nor the city’s most powerful commercial plant. The transformer shown in the foreground was used to convert the low-potential alternating current, that is ordinarily used for light and power pur- poses, into a current of millions of volts in pressure, such as would be required for sending wireless signals. The Government’s agents have simply wrapped a heavy copper wire around the trans-’° former terminals, and have se- cured the wire ends with sealing wax. on which is stamped the great seal of the United States of America. It is impossible to remove this wire without break- ing» the seal—and taking the consequences in imprisonment. Teaching the Blind How to Write on Straight Lines HE December issue of the POPULAR 4 ScrIENCE MONTHLY contained an article on an instrument invented to aid the blind in writing. This was the writing tablet invented by the French scientist Dr. Emile Ja« al, His tablet consists of a fixed elbow rest in which the writing arm swings across the paper. The line of writing is thus made comparatively straight, while~ the wire quite touches the paper surface. The straight-edge can be lowered line by line down the paper and evenly spaced by means of notches at the side. In this way a perfectly neat appearance is given to the written page. As the blind man writes, his letters are kept uniform in size by the straight-edge below the pencil-point and the wire above it A Torpedo-Proof Ship With Six Hulls It is to solve the food problem by scooping up the cut off America from her Allies, pre- venting our giving them military assistance and our supplying them with food. With his radically new inventions, a one great aim of Germaiy is to fish from the sea caused by the water’s friction. At bow and stern, she could rig herself out with strong steel gratings, and thus defy the biggest enemy torpedo afloat. It was not Ane after perfecting his sub- Nels A. Ly- marine-proof beck, of New ocean freight- York, a sea- er that Ly- man of many beck further years’ experi- developed ence, hopes to this scheme thwart Ger- into his solu- many in both tion of the of these aims. food problem. Lybeck’s Therearesuf- invention of ficient fish a multiple- scattered in hull ship util- the ocean to izes a sailing continuously principle never before used on any ocean- going ship. Six hulls twelve feet wide, and com- pletely sup- ply the Allies with food many times over. Wit- ness his truly separated by twelve feet of distance, sup- port the rectangular decks of the ‘ship. The hulls are slightly tunnel-shaped at the bottom, and when they speed over the sea, the water is packed in these tunnels,—they rise upward and slide through the water. This novel construction has still another . virtue. The largest waves cannot roll this ship. The row of hulls makes the ship act just like a huge flat-bottom scow, longer and wider than the breadth of the largest wave. The boat virtually rides on the tops of the waves, rolling but slightly even in the most violent seas. _ But what has this to do with submarines, you ask? Just this: With a rectangular, non-rolling ship it is possible to protect | it from submarines by means of torpedo- proof shields. Where V-bow boats would violently pitch when speeding on the high seas, and thereby strain their nets until they snapped off from their supports, this ship would carry a continuous, submerged steel wall on each side which would have to resist only the slight traveling strains The scoop on the speeding torpedo-proof ship is a hun- dred feet deep and one hundred and thirty feet wide twentieth century method: Three searchlights are used on his mul- tiple-hull ship at night to send their power- ful rays ten miles ahead of the boat. As the ship draws on, the ray of light becomes ever narrower, so that the fish crowd densely together as they swim eagerly towards it. Then the huge wire scoop, a hundred feet deep and a hundred and thirty feet wide, which can be readily suspended from the front of the Lybeck type of boat, is dropped in the water. The ribs of this scoop are made like whalebones, so that water and debris can easily seep through and the fish can slide up, but never down and out of it! When the teeming crowd of fish reaches the darkened scoop, this onrushing trap quickly swallows it up. Once near the end of the scoop, an endless-belt conveyor car- ries the fish to the assorting deck. Here a hundred men distribute them into cross conveyors which carry each fish into its respective refrigerator. 209 : ‘Do It With Tools Ud se Above: height. A winch for lifting heavy objects to a considerable It is permanently fastened to the floor under the driver’s seat and is geared to run by the truck’s power In circle above: his work without endangering his hands. With this nail-puller the operator can do It has a wide base so that it will not crush through under pressure Rubber hose —. Rubber hose securely ¥ held by threads Expanding sleeves forced into hose Threaded coupling ring binds outer ( Casings together Gasket” ' Flange forced down 7 keeping watertight’ 4 A metal coupling for con- necting the ends of a hose in a perfectly steam-tight joint, avoiding all leaks and Machinery At right: A “gun” for driving nails in hard- to-reach places. It is a steel rod with a brass tube shank, having’ a larger tube enclosing a light coil-spring for a hand-grip. The ten- sion of the spring is sufficient to hold the nail in the chuck end ready to be driven when it is set in place A motor-operated collar ironer with a revolving head which irons, rolls and polishes collars of different shapes without making them rough 210 A guide for use in putting hinges on doors. and frames so that the holding pins can be inserted easily Do It With Tools and Machinery Below: A neat little attach- ment for the ordinary straight-back saw blade. It is used as a _carpenter’s square for laying out work A breathing ap- paratus for use in gas- filled chambers or when working with chemicals In circle: A cotter-puller which works like a pair of scissors, holding the pin securely after pulling it A gummed paper-tape holder for feeding, moisten- A tool cabinet which is so compact and at the same time so com- ing and cutting without modious that it will appeal to any mechanic. There are spaces touching it with the hands - provided for every kind of tool that ordinary shop work calls for when fastening packages 211 The “Recruit”—Our Only Land Battleship It is New York’s recruiting center for en- listment in America’s first line of defense The battleship in Union Square, New York city, on Memorial Day HEN Rear Admiral Bradley A. Fiske published his great article on “If Battleships Ran on Land,” in the PopuLar ScrENCE Monruty for November, 1915, showing, as it’ did, the tremendous energy of a battleship on land and the destruction it would work while crashing down Broadway, New 1s city, he little dreamed that a real battleship would be anchored close to the subway in Union Square in the year 1917. Need- less to say, the land man-o’-war that now overlooks Broadway is the antithesis of the land monster conceived by Rear Ad- miral Fiske. Although it looks formidable enough, it is simply the headquarters for Naval re- cruiting in the New York city district of America’s first line of defense.- It has been aptly christened the U.S. .S. Recruit. It is a fully-rigged battleship. On the starboard side of the Two hundred American Junior Naval and Marine Scouts on the Recruit : while from the port side flies the emblem ot the Marine Corps, the “Soldiers of the Sea.”’ At the present time the ship houses thirty-nine bluejacket guards from the Newport Training Station—young fellows who have seen from two to six months’ service. Their duties on board the Recruit will not hinder their It was sev- ship flies the flag of the Navy, The Recruit'1n process of construction. eral days before she resembled a superdreadnought 212 it is a recruiting center. Popular Science Monthly progress in naval affairs, for the Recruit will be as much of a training ship as On the other hand, citizens may visit the ship and ac- quaint themselves with the makeup and - organization of a modern sea-fighter. Under Acting Captain C. F. Pierce, life aboard the Recruit is one of ordinary naval routine. The land sailors arise at six o’clock, ; ig saps.” ime Bene sc Me mt R88 213 scrub the decks, wash their clothes, attend instruction classes, and then-stand guard and answer questions for the remainder of the day. There is a night as well as a day- guard. From sundown to eleven o'clock - all lights of the ship are turned on, including a series of searchlight projectors. Within the ship are spacious waiting rooms for recruits and applicants, physical examination rooms both fore and - aft, doctors’ quarters, officers’ quarters, shower baths, a big air washer and ventilating de- vice. which changes the temperature ten times every sixty minutes, and numerous other accommodations for officers and men. The superstructure of the vessel con- sists of a forward cabin, main bridge, flying bridge, conning tower, two masts fifty feet above the quarterdeck, and a single smokestack eighteen feet above the cabin top. Six wooden guns, repre- senting fourteen-inch naval guns, extend seventeen and a half feet beyond the turrets and make up the main battery. The second- ary battery consists of ten wooden five-inch guns and two models of one-pound breech- loading rifles. The Recruit measures two hundred feet from stem to stern, witha forty-foot beam ae fais A in "stripping room sland oe “yy The equipment is that of the up-to-the-minute dreadnought with accommodations on board for day and night life of officers and men. Searchlight projectors illuminate or ship at night 214 Scraping a Bat—Why Is It Done? O, Just Because ASEBALL players are as superstitious as Zulus. In no way is this more lucidly illustrated than in the care: which some of them lavish upon an ordinary baseball bat. Manu- facturers oil. and: shellac: their bats to make them sleek and fresh, and the superstitious baseball player proceeds to use glass, bone, sand- paper and ‘what. not to removethefinish. Why? O,.. “just because” —to give a woman’s reason. He may have a notion that the bat will last longer without it. But the truth is that the shellac really acts as a preservative to the wood. Some baseball players imagine that it is impos- sible to make a strong hit with a new bat, because the bat is so sleek that the balls glance off it. Others be- lieve that scraping a bat fills up the crevices and cracks and thus lengthens the life of the bat. The ac- companying photograph shows Cueto, a Cuban who plays an outfield position for the Cincinnati Reds, combing his bat with a calf bone. A baseball player may change his bat occasionally for a lighter or heavier one, and when he does so the Cueto, of the Cincinnati Reds, combs his bat daily with a calf bone Popular Science Monthly An Improvised Street Railway Smoking Car NCREASED traffic and car shortage on a street railway property in the East during the past winter months made . some of the operative heads do quick \ scheming in order to cope with the situation. As a result, some of the open summer cars were equipped for ‘‘shop service’ in winter. The company took ordinary fourteen- bench open cars and placed electric heaters under the seats, except the two end seats and the two seats corre- sponding, just inside the bulkheads. The heaters have _sheet-iron guards on each side to prevent contact with the passengers” shoes or clothing. Tests showed that such a battery of heaters pro- vided a comfortable tem- perature. In order to retain the heat thus generated in the car, the sides were equipped with transparent, non-in- flammable windows. These flexible win- dows in the curtains provided ample light for reading. To encourage passengers to ride on the cars they were run on express schedules and termed ‘‘Express Smoking Car.” principal sporting goods stores in the country are at once apprised of the fact. One big store, for instance, has on hand the exact weight and style of bat used by every big league player in the United States. When a player breaks his bat all he need do is to send a telegram such as this: “Express me a bat, quick. Tom Jones,” and he-will get a duplicate of the bat he broke. Most bats are made of second-growth Northern ash, dried in the sun. This wood is becoming scarce. An open summer car equipped with curtains, heaters and windows, for a “smoker.” It ran on an express schedule All the specialized knowledge and information of the editorial staff of the Popular Science Monthly is at your disposal. Write to the editor if you think he can help you. at hill on which the house stands. He Finds a Coal Mine in His Cellar Coal may sell at eighteen dollars a ton but this for- tunate lawyer can have all he wants at thirty cents The vein of bituminous coal found in the cellar measures five feet in width At right above: It’s only a step from the coal mine to the hot-water heater HE purchasers of property in the residence section of Norton, Va., will hereafter be inclined to ex- amine the cellars of their prospective homes very carefully in the hope of locating some such bonanza as did H. M. Bandy recently. Mr. Bandy was excavating in the cellar of his newly-purchased house in order to install a hot-water heating plant. Almost on the spot where the furnace was located, an old negro workman discovered the “bloom,”’ which is a black carboniferous earth found always on the edge of a stratum of coal. ‘Boss, youse got plenty of coal back up in the hill,’ the old negro said. “These am the outcroppings.” By the time the cellar had been excavated to the desired width, enough coal had been taken out to supply the family for the entire winter. Then Mr. Bandy started to drive a “heading’”’ back up into the The heading, which leads from the furnace out under the garden, is ten feet wide. Mr. Bandy has installed a small track of wooden rails on which a hand car can be pushed back and forth for loading and unloading. As the vein of coal is on a grade, even this work has been simplified for him; for when loaded, the car slides down the track to the dumping place almost unaided, and The home of Mr. Bandy, under which the vein of “coal was discovered when emptied it is a child’s task to push it back to the loading place again. This down-hill grade also provides natural drain- age for the mine, keeping it free from the water which seeps into it from the garden immediately above. At present the mine is yielding from ten to twelve: tons of-coal a day, with only one miner employed. Dynamite is used in minimum amounts to loosen up the strata and lessen the work of the miner without disturbing the inmates of the house or the rapidly developing plants in the garden. The town of Norton is in the center of a big bituminous coal region. According to the local recorder, ‘‘Dig a post hole and up comes coal. Lay a waterpipe, and some coal has to be removed from the right of way.” Mr. Bandy’s private coal supply costs him about thirty cents a ton. _ 215 216 Instead of climbing the flag pole to repair it, one man lowers it to the roof where it can be painted with less danger his THe 4ULLWire cablesto || Lerra lower rigging Flag Pole Repairing Minus the Usual Steeple-Jack PECIALIZED pole painters and_ steeple- jacks may soon find them- selves unnecessary adjuncts to the business world, if the ingenious flag raising and lowering device shown in the accompanying illustration becomes popular. It can be used on all flat roofs. Instead of the men climbing the pole, the pole is brought down to the men by means of a system of gears, which can be operated by one man. These gears are mounted on a short hollow post which is fastened to the building. They operate a drum which is divided into two portions. Upon these portions, the pole tackles wind up. The drum which winds up the cable going to the top sheaves is larger than the other, so that this cable will wind up faster and keep its tension the same as the lower cables, as the pole swings up on its hinging pin. When fully raised, two stirrups hold the flag pole securely against the shorter anchoring post. | | || Wire cablesto Pele top rigging iDrums| with hand gear Popular Science Monthly The Tender Chloroforming, Antiseptic Bayonet—It Wounds and Heals Ho can we make the soldier fight harder? Can we do it by giving him new implements of torture, new weapons to increase bloodshed? ‘‘No,’’ is the answer _ of Alexander Foster Humphrey, of Pitts- burgh, Pa., inventor of the gentle narcotic hunting bullet and the polite antiseptic, anaesthetic military bullet. “Relieve the conscience of the soldier,” advises Mr. Humphrey, ‘‘and he will fight the harder. Let him know that while he must cause a wound, he is also giving means to relieve and heal that wound and he will fight like a tiger.” All of which whether true or not serves as an introduction to Mr. Humphrey’s most recent and most astonishing invention, the antiseptic, pain-deadening bayonet—a bay- onet that carries in its blade a capsule con- taining a mixture of antiseptics, anaesthetics and gelatin. When the bayonet is plunged into a soldier the heat of the body will melt the capsule and release its healing contents, the anaesthetic deadening the wounded man’s pain, the antiseptic preventing in- fection, and the gelatin stopping the flow of blood. Wewonderifa Belgian soldier would relish the stabbing of a German so tenderly. The bayonet which heals the wounds it makes. A groove in the end of the blade holds an antiseptic, anaesthetic capsule Popular Science Monthly A New French War Word Which Means ‘Fooling the Enemy’’ INCE the war started the PoPULAR ScrENCE MonruHLY has published pho- tographs of big British and French field pieces covered with shrubbery, railway trains “‘painted out”’ S17: A Motor-Fan That Works Without Electricity ; t LL the benefits of the electric fan may now be had in places where elec- tricity is not available by using a fan driven by a motor operated by alcohol, gas, or kerosene. The mo- of the landscape, and all kinds of de- vices to hide the guns, trains, and the roads from the eyes of enemy aircraft. Until recently there was no one word in any lan- guage to explain this war trick: - Some- times a whole para- graph was required -to explain this mili- tary practice. Here- after one word, a French word, will save all this needless writing and reading. tor isereally an adaptation of the air engine. The al- cohol lamp or other source of heat is placed at one ( end of the cylinder. This causes the air in the cylin- der to ex- Piston stem Inner tube 4 4 Outer tube Camouflage is the new word, and it means “fooling the enemy.’ Example: —A dead horse lay between the British and German lines on a bit of rising ground. During the night the dead horse was re- moved and an imitation, with a man inside, was substituted. The men who constructed and painted the fake horse practiced camou- flage. They are known as camoufleurs. The motor of the fan is operated by kerosene, alcohol or gas. shown a diagram of the equipment At right is Gasoline tank Kerosene lamp pand and to Gas hose attachment exert pres- sure on a sliding piston at the other Gas burner end. ‘This acts in such a manner as to push on the crankshaft. A second piston, called the transfer pis- ton, at the proper time forces the hot air from the burner end to the cool end of the cylinder, where it cools and contracts. The atmospheric pressure then pushes back the sliding piston, which pulls the crankshaft. Thus power is exerted on both the upward and downward strokes. The same air is used over and over again, obviating the need for an exhaust and preventing odors. The small fuel tank, placed in the lower portion of the stand, holds enough fuel to last for a twenty- French Official Photo Camoufleurs, members of an important camouflage detach- ment, are here shown hanging mats of leaves on a frame- work of tall poles, to prevent the enemy from seeing the road four-hour run; it drives the fan at 500 to 700 revo- lutiong per minute. WH WSS Why They Were Rejected LLU ny “iby, aa ee, : << WE Photos ©) Press Illus. Serv. Stand up straight, lift the right -leg and say “Uncle”? three times. Ah! ha! he’ has flat feet; hammer and over- riding toes, corns, bunions and ingrowing nails. He couldn’t march far. Otherwise he is admirably fitted for military service. Admire the Junoesque arm if you must The color test or does black belong: above or below the Mason and Dixon Line? It is a hard test, this color gamble. You are given five minutes to pick black from white and if you fail the first time you are only given two other chances. A color-blind person can’t shoot straight \ N N aN MMA AAAS SSSASSSSSSSSISS Vy >>» > dry N : ral Hold that pose, Oscar, while we count the molar stalactites and stalagmites in your Mammoth Cave. By Jove, old top, you have six ivories missing. Sorry, but that dis- qualifies you. Yells Oscar, “Isn’t “it enough to kill the Germans. or do I have to eat ’em too?” Bad teeth mean rheu- matism and poor health “You listen well,” says the doctor,. musingly, “but I can tell from the way your internal gears” mesh that you would travel in ‘low’ when leading a charge. Breathe naturally now, and, I’ll see. whether your heart has a little movement of its own ornot.”” The recruit is murmuring the prayer, “Oh death, where is thy sting-a-ling?”’ Uddddddddddddddddddddddddddddddidddddddddddssdubddddiddddédlddddidddidddddddaéa 918 Why They Were Rejected pplpitOliDlcleeclll etary Ca; ca g > ‘ Ka Ks C & sda Has he a little Prussia in his dome? Let the doctor decide this, and also pass upon his hearing. The Marine Corps demands that a ] VE recruit have good hearing, otherwise how j > would he know to obey an order to retreat Ze At right above: Taking his measure. If the heigh Wty, t limit is five feet four and the recruit but five feet three it is possible (so they say) to make up the extra inch between the waist line and shoulder. Seven-foot soldiers aren’t nice to look at; four-footers can’t march fast enough Malet “el elle ae Photos © Press Illus. Serv. AANA NAAN Underweight? Go home, fill up on olive oil and milk and go to bed. Overweight? Pick out a forty-storied building and walk to the top ten times a day. Fat men can’t stand the pace; skinny ones haven’t the endurance RRA Close one eye and see if you can pick out a German at twenty feet. Very good. Now close the other and see if you can read those letters. Fine, you will make a sharpshooter after peace comes and firearms are taboo 919 220 A Dinner Served in Gondolas on a River of Champagne Popular Science Monthly the skirmishing first line, seeking to destroy the German machine-guns. A machine-gun destroyer it is in very was con- structed ‘with a canal about a foot wide running round it. The ends of the canal were ex- tended into the kitchen where a water wheel lifted the liquid from the lower end of the canal to the higher end. The gondolas were loaded with meats and viands at this end and sent on their journey. Fighting German Machine-Guns with the French ‘‘37”’ “HE great work of the French ‘75’ in counterbalancing the mass of Ger- man artillery in the present war has justly made it famous. But in that work it has had a smaller ally, not so well known though de- serving of most honorable x mention. This , ae is the French : “37, a small quick-firing cannon which advances with © Int.Film Serv. The gondolas loaded with dainties float from the kitchen to the guests and back again, on a flowing river of ‘‘stage’’ champagne This French portable, quick-firing cannon advances with the skirmish line to destroy the enemy’s machine-guns HE dinner being served in the accom- truth. Germany relies on machine-guns panying photograph is Solaire teed the and artillery to hold a battle line. Machine- wettest on guns and record. It light artil- literally lery, then, floated on retarded the champagne advances of (the stage the French variety). As —until they one might answered suppose |the cannon with novelty is cannon in the product the famous of the com- “"75 ena bined imagi- the distin- nations of a guished motion-pic- va - turedirector A more and his tech- beautiful nical assis- weapon tant. The than the scene repre- “37” for fill- sents a ban- ing the rigid quet ina require- recent Fox ments of a produc- ~ skirmishing tion. cannon is A table not to be found any- where. It ably meets the first requisite of portability; the gun and mounting can be quickly taken apart and carried over the most shell- torn ground by the six or eight members of its crew.. It is accurate—a French officer says there exists no other gun more ac- curate! It will hit the muzzle of a machine gun at a distance of a mile. And its speed of fire is remarkable... A well trained crew, can fire thirty-five high-explosive shells, of nearly one and a half inches diameter, every minute, while they are crouched upon the ground to conceal themselves from the enemy ! Military ex- pediency pre- vents the pub- lic from know- ing ‘the details ofthismachine, but when the story of this ° war is told, the “37” willnot be found wanting. Popular Science Monthly Filling Nine Thousand Cans of Beans an Hour RMIES may fight with bullets, but they live on beans. The Civil War was fought on a diet of our dried army beans; this war is waged with canned beans. In the photograph below is shown a modern bean- canning factory working at the height of produc- tion. To meet ‘the ex- traordinary demand for beans, labor-and time- saving machinery is used. exclusively. Al- though located in New Jersey the machine il- lustrated fills up the cans ‘with Boston baked beans and snaps on the covers in practically the same opera- tion. The empty cans are fed to the machine in an endless stream, the cans being held in place by a metal frame. The machine fills the cans at the rate of nine thousand an hour but it can work faster, if needed. The largest mouth in the world— a model for a dentists’ exhibition 221 The Largest Human Mouths in the World R. GREENBAUM, an enterprising -young dentist in Cincinnati, eager to help Uncle Sam in demonstrating to the —. volunteer the necessity of getting > __ his mouth in good shape before enlisting for the front, de- vised what are probably the largest _ scientifically-cor- rect models of the human mouth in the world. Each model (and there is an extended series of them) is two feet. deep by eighteen inches wide and eight inches tall. The mod- els are hollow and fash- ioned of plaster-of-Paris, held together by gauze. Ten models of the adult mouth, three of the child’s and four panels emphasiz- ing certain phases of disease of the teeth and of decay, comprise the set. The models show the pulpy substance containing blood vessels, nerves, as well as the harder root and bony portions. Europe Is Starving for Gasoline RANCE, one of our largest automobileand truck buyers, has prohibit- ed theimportation of foreign motor vehicles, except for government account sim- ply because of the difficulty of obtaining gasoline. Gas- oline is now selling in France at about a dollar a gallon. Each automobile owner is allotted a small amount per week. — India and Holland have likewise prohibited the importation of motor vehicles for the same reason. Denmark’s gasoline situation was so acute that it stopped the driving of passenger cars through the steets. It is said that taxicabs in Berlin have been running The bean-filling machine with its funnel is in the foreground. To the left are the solderers which seal nine thousand cans an hour on alcohol for two years now. 222 A Ten-Thousand-Dollar Map of Warring Europe N the lobby of one of Chicago’s large office buildings is a huge relief map of the European countries where the war rages, exhibited to Popular Science Monthly scaled and little pegs driven down for measuring the mountains. A clay map was then made on this frame and a cast taken, from which the plaster of Paris map (the one on display) was made. The next task was to shave the map and gradu- ate it, after the public which the and lectured various parts upon by a were indi- former war cated and correspon- colored. At dent. The thesame time main map is 10 x 20 feet, but owing to its convex construction _ it contains an area of 300 square feet. It is a seg- ment of ago- |e foot globe. It |“ i was made by l= | William Rob- ————— See ee the wiring system for the incandes- cent lights was installed. The scale of the map is. one inch to every 7.8 miles. It shows. the topographi- cal detail of ertson, with theassistance of ten men. It took them nine months to make it. Including labor and materials, the cost of the map is estimated to be $10,000. A special feature of the map is a system of small incandescent lamps which are flashed in connection with a large signboard made up of two hundred small transparent illuminated signs, each bearing the name of an important point on the map. When the lecturer mentions an important point in the war territory a light flashes at that point on the map and simultaneously the name is flashed. on. the large sign which is located at the left side of the map. This makes it possible for the spectator to follow the lecturer more closely and in- telligently. The method used in ¥ constructing the map is interesting. A work- ing model. was first made. From this the frame was laid out, the map scaled and the countries outlined. The vertical parts were next The map is a segment of a 90-foot globe, with heights and depressions clearly represented. Every battlefield is shown A simple bell-action attracts the arma- ture and re-tightens the helical driving- spring whenever the watch runs down every battle- field. An Electric Self-Winding Clock for the Automobile EAK-CURRENT electricity is in- terestingly applied in the self-wind- ing mechanism of a clock which has been specially designed for the dashboard of the automobile. A simple electromagnet is made to drive the clock, and but three or four batteries are required. In construction, this clock dif- fers little from any other. The gears, however, are mounted to withstand the jolts of traveling. And instead of the or- dinary hair-spring a straight helical spring furnishes the motive power. The armature of the elec- tromagnet works - much like that of a bell; it tightens up the driving-spring every. time it is attracted to the magnet. The spring loosens up whilerunning the clock, the armature swinging slowly back. It Always Turns Right-Side Up A boat which will carry twenty-five persons and will not “‘spill’’ even f° type of life boat is the fact that almost no provision is made to protect the passengers from anything ex- cept actual drowning. Even here the pro- tection is not complete, for in the heavy storms that sooften cause the mother ship to be wrecked the little life -boat is tossed about unmercifully, and its occupants sometimes swept overboard. é Mr. A. D. Newcomb, of Hampton, Va., has just perfected a life boat of entirely new design which is expected to meet this difficulty as well as several others. The Newcomb boat is completely closed, with manholes in the top by which to enter, and is water-tight. It might be supposed that it would necessarily be air-tight as well, thus depriving the passengers of oxygen, but ventilation is provided for bya particularly ingenious contrivance which admits air only. This de- vice isa sort of valve fitted with a rubber ball. The air passes around the ball, but water causes it to float and thereby closes the opening. Another ingenious fea- 4 7 4 hoe chief objection to the ordinary if turned upside down iota ~ ei In a test made by the Department of Com- merce the boat was rolled over. It righted itself without inconvenience to passengers in the excitement of launching. Sometimes they have to be cut loose. And in case the mother ship sinkssuddenly, the “>. life boats tied on deck sink \ with her. N In this new boat all the —\_ cables are attached to semi- ween, §=circular bolts which work on pivots. By pulling a lever one end of the bolt ture is a water-tight oar lock. Oars are not fur- nished with some types of life boats, since it is foolish to attempt to row to shore: Nevertheless they are fre- quently valuable in guid- ing the boat to persons in the water. This oar lock is made as follows: A canvas sleeve is fastened tight around the oar at the point where it fits in the lock. The border of this sleeve contains a wire, and this in turn fits into a groove on an oval iron collar surrounding the opening, or port hole, through which the oar protrudes. When the sleeve is adjusted and the wire drawn tight no water can enter, yet the boat can be rowed with ease. Perhaps the most useful device of all, however, is an arrangement for freeing the boat from davits and cradle by levers in the boat itself. Often, under the present method, the ropes are hopelessly tangled There is an each side of the turtle back. The boat weighs 2600 pounds is released and the cables drop free. The boat is twenty- six feet long, six feet four inches wide, and three feet four inches deep. The superstruc- ture or turtle back is one foot eleven inches in height’ above the hull. There is a metal bulkhead at each end, each bulkhead having a 16 by 16 inch open- ing to be closed by a metal plate on rubber gaskets. There are seven thwarts, seventeen inches high from the skin, or inside bottom of the boat. The oar locks fit into the three port- holes on each side. The three hatches or manholes on top of the superstructure are twenty-four inches in diameter, and are provided with rubber gaskets, each fastened with brass turn buckles and a safety lock. The steamboat Inspection Service of the Department of Commerce, after testing the boat thoroughly recommended its adoption. 293 ° offset on deck on 224 The Latest Device for Easy Entrance to Automobile Doors Popular Science Monthly 4,000 lbs, meat 1,400 lbs. of sugar 1,200 lbs. beans 1,500 loaves of bread 50 bags of potatoes 100 lbs. of tea 300 gals. of milk 500 Ibs. of butter HE last word in easy-entrance auto- mobile doors permits direct entrance to both the front and reaz seats of a close-coupled four-passenger roadster. The special feature of the design is the fact that one-half of the front seat opens with the door. When closed, the division in the seat appears as a fold in the upholstery. The door may be opened from either the front or year seat. It is provided with a safety lock to pre- | ‘vent its opening of its own accord while the car is in motion. It is hinged on two heavy concealed hinges at the front’ and runs ina track ee so that it cannot spring out of position. The Largest Traveling Kitchen in the World HE ordinary dining-car, compact as a watch in its arrangement, can feed thirty persons at one sitting. The commis- sary car illustrated, which One half of the front seat opens with the door, making easy entrance to front and rear , 400 lbs. of coffee 600 lbs. of oatmeal In the movement of a battalion, two com- missary cars are used, the military special being run in two sections. The big dining- car is placed in the center.of the train in order that it may be readily accessible to the waiters, who enter it from both front and rear. As soon as the first twa coaches have been supplied, two more squads © of waiters arrive untilall are served. Within fifteen | minutes after the dinner bell has been sounded the men are all busy with their meal. Along the wide kitchen counter are spread the If it is breakfast age various portions of food. time and the morning menu calls for oat- meal, meats, potatoes, bread and butter, jam and coffee, the food is served about as follows:—Two men take the big trays of meats and potatoes, another the bread, coffee, and so on, until all the food has been carried away on the trays. is the type used by Canada in transporting her troops, can feed 1,200 men at one sitting, and the food can be served in fifteen minutes. The Canadian commis- sary car is the largest travel- ing kitchen in the world. It is eighty feet long, has a full- size hotel range, steam- cooking apparatus, and sixty-foot refrigerator space and store room capacity for tons of provisions. Eight cooks work in it without interfering with each other. A battalion of 1,200 men en route from Camp Borden, 2 pis Ontario, to Halifax, Nova Scotia, consumes: The kitchen of the Canadian commissary car. : eight cooks. Food for 1,200:men can be served in fifteen minutes It accommodates Old Before She Was Launched There are styles in airships as well as in derby hats. The D.N. 1, our new navy schoolship-dirigible, is mew and yet so old tures of some TWO years ago, the United States Navy contracted for a -small - dirigible to serve as a schoolship. Now that the craft has been finished, now that it can be judged in the light of the European war, it must be wholeheartedly condemned as well-nigh - Thedesigners of the D. N.1_were not daringly original. They simply copied an \] Austrian airship, the {’ ds Koerting, destroyed short- ly before the war in a collision with an airplane. A few fea- 1 fo res / W utterly use- - less British airships (des- ignated by Greek letters Alpha, Beta, etc.) were in- corporated. “‘In-. the © Int. Film Serv. so that it may carry an apprentice crew of seven. Three or four apprentices would have been a more reasonable number. The whole idea of the D. N. 1 is funda- mentally wrong. There may be some justi- fication in degrading an old diri- gible, which has seen active service, to the level of a schoolship, but there seems no_ excuse-~for - designing an en- tirely new dirigible which is so -slow that the experience to be gained in it-is not even remotely ° similar to that re- quired of the =. men in full- sized fast military orna- val airships. An air- plane has what is called dynamic lift; that -rs,-tt Koerting, the car was elon- gated fore — The D.N. 1, the navy schoolship-dirigible, is 175 feet long. It has a 140-HP engine to drive it at a speed of 25 miles an hour. Although new it is hopelessly antiquated rises by vir- tue of its own fast motion. and aft to receive front and rear suspension ropes. Thus the strain on the tender gas envelope was lessened. Inthe D. N.1 that system of suspension is copied. The Koerting had two motors so that it was safeguarded to a certain extent against breakdowns; but the D. N. 1 must make the best of a single motor; The two pro- pellers of the D. N. 1 are driven by bevel gearing, the arrangement being such that they can be swiveled. Hence, the craft can be pushed up or down by its propellers while it is making very little headway—a decided advantage in landing and starting. The D. N. 1 can be tethered by the nose of the gas envelope to a tall mast so as to ride out storms—a good idea because the ropes distribute the strain evenly over the envelope. The Koerting was never regarded in Europe as a model to be followed. The D. N. lis worse than the Koerting. Its fuel capacity is sufficient only for two hours A dirigible, too, has dynamic lift when it is fast. A slow dirigible has little or no dyna- mic lift. The whole science of piloting a dirigible is founded on the proper utilization of dynamic lift—a fact which we have learned in this country although the ex- tensive German literature on the subject has harped on it constantly. In a dirigible of twenty-five miles an hour (the speed of the D. N. 1) little more can be learned than in an ordinary spherical balloon. The faster the dirigible, the safer will it prove to be for an apprentice. Its dynamic lift makes it easy to overcome mistakes in managing gas and _ ballast. Moreover, a fast dirigible is not easily forced to land; and an enforced landing is the worst danger because no dirigible can come down :anywhere in safety like a spherical balloon. Even the English 4/pha, Beta, and Gamma ships have been discarded in favor of the ‘“‘ Blimps.’’-—small dirigibles whose cars are wingless airplane bodies. 225 226 Turn It at Any Angle. It’s Always Read7 to Shoot EVERAL attempts have been made to mount machine guns on automobiles and motor boats. The principal problem to be confronted is that of vibration. In every case the inventors have devised several forms of Popular Science Monthly vised, but it is so high that the starting platform has to be reached in an elevator. A steel car takes the place of the old pine board. From three to ten persons may be swung through space in the same car. The car is suspended not from a rope but from metal rods, preferably of steel. The tower which supports the swing is composed of mountings which would lessen to a considerable degree vio- lent shocks. Needless to say, they have been hard put to ‘it/to devise a mounting that would stand up under the ex- cessive vi- bration of a traveling A machine-gun mounted on a ball and socket base fastened | steel pillars; so is the ele- _ vator build- ing, as well as the ele- vator itself, The swing chair or car is held in po- - sition on the starting platform by a locking de- vice. When the car is ready to be released, a lever is oper- automobile. permanently to the floor of an automobile. It can be fired at ated which The ac- any angle to straight up without changing or altering lets the car com panying fall. The in- illustration shows a new mounting for a machine gun which enables the gun to be fired in any direction without changing the base. A ball and socket joint gives the greatest possible latitude of range, and the gun.can be fired at any angle to straight up. -The flanged base and about one foot of the supporting column are attached. per- manently to the automobile floor. The stand can be lifted off this ventor does not tell us whether or not the car will return to the starting platform every time it is released. Neither does he explain how the car is brought back to the starting platform.’ Perhaps he figures that with a minimum of resistance it will return to the platform and thus be caught and held by the locking device without further trouble, base and put on another car, or by driving its pointed end into the earth it can ‘be used for land firing. A Giant Swing for the Summer Resort NSPIRED by the swing ’neath the old apple tree, Frederick E. Happel, of Ballston, Virginia, has devised a giant swing for parks and recreation centers to thrill even the person who has grown tired of turning figure eights, riding down the roller coaster, and chuting the chutes. Not only is Mr. Ballston’s swing by far the largest ever de- The giant swing isan overgrown edition of the old apple tree swing... It is made of steel ME ers, champion Two and a Half Miles a Minute That’s the speed at which a pitched ball travels Providence, R. I., who is known te all over the world as an efficiency engineer and who has specialized in motion study, knows M:* FRANK B. GILBRETH, of With White in the box, Mullaney catch- ing, and Snodgrass at second, it required 4.407 seconds to pitch the ball (including the ‘‘wind-up’’) and to return it from the batter to probably more about cham- pions than any other living man—cham- pion golf play- fencers, cham- pion baseball players, cham- pion handker- chief folders, champion sur- geons and champion typewriters: In his effort to dis- cover the fun- second for a put-out. The actual time that elapsed from. the mo- ment that the ball left the hand of the pitcher to the moment when it dropped into the glove of the second baseman was 1.697 seconds. The actual time consumed from pitcher to damental laws of human mo- tion, he studies every sport and every handi- craft. But he studies with the camera— the motion-pic- ture camera— not with theeye. _ Since it is necessary to know the time occupied in carrying out a2 given motion, sometimes to the thousandth of a second, and since camera cranks are never turned uniformly, Mr. Gilbreth has invented a special clock which is photographed with the scene. It is a very peculiar clock; for it has only one hand which makes six revolutions every second. That clock ap- pears on every film and the position of its hand enables Mr. Gilbreth to determine the speed of a motion down to the one-mil- lionth of an hour. Behind the catcher, a background is hung, ruled off into one foot squares. Every movement of the pitcher, catcher, batter, ball and bat is photo- graphed against that background. Thus by referring to that background in the film the direction and extent of every mo- tion can be accurately determined. miles a minute. recorded. The clock and the background used in connection with motion pictures of a baseball’s flight. breth’s tests, Fromme pitched a ball which, including the’ wind-up, required only .99 seconds until the batter hit it. The time consumed from the moment that it left the hand of the pitcher until it reached the bat was 0.288 secorids. The ball therefore traveled 210.07 feet a second, or 2 2-5 Even speeds of 2.8 miles have been In that case the batter occupied 0.042 seconds swinging and striking the ball; which means that he began his swing when the ball was 9.24 feet in front of him catcher was 0.351 second —a rate of somewhat more than two miles a minute. The catcher re-. covered to launch the ball at second base in 0.317 sec- onds. It required only 0.796 seconds to throw the ball from catcher to second base —a distance of 129 feet. The record for a 100-yard dash is only 9 3-5 seconds. No wonder bases are difficult to steal. Mr. Gilbreth’s films are interesting in showing how long it takes a player to make up his mind what to do next. A baseball player must make quick decisions. A delay of a tenth of a second may be fatal. Strange things are revealed by Mr. Gil- breth’s camera. So swiftly does the ball travel that it is struck by the bat before the pitcher’s foot has risen to its full height from the ground. Some pictures show the ball in the catcher’s glove before the batter even began to strike. A baseball nine is a model of teamwork. And yet, even the New York baseball nine knows less about itself than does Mr. Gilbreth. In one of Mr. Gil- 227 228 Popular Science Monthly . A gigantic pencil which when fully extended was seventy-five feet long. Eight of its “‘points” could not only write but talk. But it’s a stingy pencil despite its length; it hasn’t any eraser Here Is a Pencil with Nine Good Points T a masquerade ball recently given in Oakland, California, by the advertis- ing men of that city, there appeared eight girls standing in single file and - wearing cone-shaped hats which resembled the points of pencils. They were enveloped in a clumsy, bag-like device which had a big point at the front end. A signal being given, these girls stepped forward one by one. To the amazement of the on-lookers, they presented a gigantic pencil, seventy-five feet long and thirty inches in diameter. For once a _ pencil became longer with use. The Latest Enemy of Lost Motion—the Portable Elevated Saw N all manufacturing plants using steel rods, considerable time and labor were formerly required to carry the heavy rods from their racks to the sawing machine and back again when short pieces were to be cut off. But thanks to a new portable elevator de- signed especially for carrying the electric saw, there is_practi- cally no loss at all. When it is necessary to cut off short pieces of different diameters and shapes from the stock rods, the elevator is simply hauled over to the racks. By means of asystem of reducing gears such as are used The saw is simply raised or lowered to the racks containing the different sizes of stock. It takes the place of six men on all hand derricks, the elevator platformon which the electric saw is mounted can be easily raised up to the level of any rack. A rod on this rack has then to be moved a.foot or two to feed it into the saw. Ina few minutes the biggest rod is severed by the hack saw as it mechanically receives its rocking motion from the motor. In order to cut other pieces of a different size, the platform is merely lowered in its guides to the level of the racks which con- tain the stocks of the proper diameters. It would ordinarily require six men to carry the heavy rods across the room, but by this means one operator can do it alone and in half the time. Deadening Noise by Past- ing Tar Paper on a Concrete Floor Y pasting heavy tar’ paper to the con- crete floor of a factory the thundering noise of passing trucks can be eliminated. The floor is first given a coating of gray ce- ment paint and, when that is dry, a second coating is then applied. At the same time one side of a five-ply tar paper is painted and when both paper and floor are wet the paper is laid wet side down on the floor and rolled until all air- pockets disappear. This gives a tar-paper flooring which acting as a muffler, deadens all noise from trucks or heavy vehicles. 4 3 4 government for use in raising England’s- Putting Alcohol to Work on the Farm The stuff that destroys brawn and brain prom- ~~ ises-to be the inexhaustible fuel of the future ROMISING to be on. land. what our great fleet of new steel ships will be to _ England on the seas, the Ford farm tractor shown in the accompanying illustra- cendency of machinery over manual labor. Besides the light weight and cheapness of the Ford tractor, its main characteristic is its ability to burn alcohol and kerosene tion has been presented to the British with the same ease as gasoline. The supply Auxiliary alcohol tank Worm gear Driving axle i Dn Soe == housing. ee 4 Cd 4 Z 4% a The tractor which is run by alcohol. automobile, except that it is larger and heavier. crops during the coming season, even before a single one has been sold in this country. Shortly after America’s entrance into the war, Mr. Ford cabled the complete specifi- cations to the British government and offered to build the parts for a thousand such tractors in a new plant in Cork, Ireland. Although this raised a storm of _ protest on the part of British agricultural machinery makers who were afraid that America would obtain a firm foothold in the British market, the plan is proceeding rapidly. It is expected that the simplicity and cheapness of the Ford Agrimotor will make it possible for this year’s crop in England to be harvested more expedi- tiously-than ever before, because of the as- ‘ discover. The motor is exactly similar to that used on the Ford Kerosene can also be used .as fuel of alcohol is as limitless and inexhaustible as the air and water, while the supply of gasoline and kerosene is growing smaller and smaller every year with no natural process of replacement that scientists can Thus it may be that the havoc which alcohol has wrought in the past may be offset by the good it will accomplish when utilized as a fuel not only for farm tractors but for all forms of vehicles with internal-combustion engines. When that day dawns breweries will still be making alcohol but not for drink, and there will be motor carsin numbers beyond present belief. The motor used on the tractor is exactly similar to that used on the present Ford passenger automobile, except that it is considerably larger and heavier. 299 : Death-Traps on German Liners The harrowing task of investigating an interned German liner with the possibility of setting off a bomb or plunging into a pitfall at every turn fi . of tomless chasm, and that, if you value your od life, you must not touch a thing—wood, met- al, or cloth—without first investigating it. How would you like to explore such a ship with only a flashlight to guide you through the abysmal blackness, and with no means of communicating with friends on the top deck once you start on your perilous journey? This was the task assigned to a certain engineer in New York shortly after the Government seized the interned German ships in this country. It was a task fraught with the greatest danger, requiring an extraordinary degree of caution © and patience, and calling for a rare display of courage. But so fearless was this young engineer and so successful was he in his undertaking that thirty-six hours after the ship in ques- tion reached the Navy Yard, the main boilers were generating steam. Among the interesting. Holes drilled ready to knock out piece the intrepid in- vestigator were the location of missing parts of Cylinder walls were ruined by drilling holes and knocking out the portion within the holes A corner flange on one of the circulat- ing pumps and another on a steam chest were broken off with a sledge hammer Cylinder wall ship, five hundred and s forty-five feet long, seven- ty feet wide and over fifty feet deep—as black and forbidding as a Siberian copper mine, with not a ray of light from the up- permost deckhouse to the cav- erns of the lowest holds, in the damp and slimy bilges, or in. the rooms filled with engines, pumps, dynamos, pipes and valves without number. Think of exploring it, single- handed, with the warning fresh 3 in your ears that it is full of pit- q Bent piston falls, bombs and death-traps; rod To K of a great ‘deserted . VU J Jack screw that every door you touch will set off an explosive which will blow you into eternity; that every ladder you step on will send you sprawling down a bot- The steel wedge was driven in the cylinder head to break the piston and the stuffing box at one stroke. The engine was cranked over to cause the damage _ 230 On one of the main en- gines a jackscrew was placed in the low pressure slide-valve chamber and a portion of the cover was broken out as shown above finding of steel wedges fitted into steam- ports, so that any attempt to turn , over the engine would have ruined it; the discovery of ob- structions in pipes, smokestacks What would have happened had the damper-chain been pulled. Over one hundred pounds of iron and coal would have fallen on the " unsuspecting person How the German trap on the Friedrich der Grosse was dis- covered by means ofa flashlight and a bit ofingenuity. The light was lowered down the ventilator and its rays played on the iron and coal which had been placed on the damper to fall on the head of the person careless enough to pull the damper chain as shown in the picture above Joke No. 1. A device which was thought to be a death-dealing trap. The string enabled the occupant of the stateroom to open the ventilator without un- locking the door. What a relief! Popular Science Monthly ec 231 the main engines, carefully hidden away in the coal bunkers; the discovery of boltsand — nuts which led to a minute examination of the cylinders and steam-chests, where it was disclosed that parts had been removed and other parts carefully substituted to conceal the omission; the location, in other places, of studs and bolts partly sawed through, with the saw slot filled up; the Blueprints of the. important details of the ship were concealed. They were tacked to the underside of bureau drawers and boxes. In cleaning out the drawers they were discovered and ventilators—lumps of coal and bars of iron placed on top of the closed damper-valve in a ventilator, requiring only a pull on the damper-chain to precipitate the entire load down on the head of the person foolish enough to pull it, and other traps too numerous to. mention here. Down in the engine room and into the boilers, went the man with the flashlight, crawling in through one small manhole and in and out of the slimy tubes and shell, where one misstep would have meant serious injury. The long disused Brass tube caps on Rope end containing nothing ved placed in boiler Joke No. 2. When the rear man- hole plate of a boiler was re- moved a fake ‘‘bomb’”’ was dis- covered in the position shown. Thereafter every boiler was mi- nutely searched for a real one ’ 232 ae Popular Science Monthly Small bolts holding together the lagging of steam connec- tions were sawed half through and then replaced. Had the steam chests been under pressure the bolts would have broken and an explosion would have taken place Holes drilled in ; cover of pump and filled eine tar, black dirt, ete: y bolts sawed half way. through Holes were drilled in the cylinder-heads of pumps, filled with dirt and then painted over, with the anticipated hope of giving someone an unexpected bath had the pumps been started before the holes were discovered Section of flange Othes flange drilled around and drilled ready , broken out with to break out, sledge hammer. Broken flanges on main steam elbows. The sec- -tions were first drilled fire-room came next, rate hand every nook receiving the ” closest scrutiny. Then pipeic came a trip through the engine furnaces, the combus- Valve stern tion chambers beyond, the grimy uptakes and the long and tortuous connections of the great smokestacks and up around and then broken out with sledge hammers At left: The main throttle valves had been removed and destroyed, leaving x Main stem pipe from boiler their sooty ladders to what should have been the sky, but what proved to be heavy wooden covers fastened across the stacks, all carefully concealed from view. onlytheempty valvebodies This task done, the engine room was reinspected, locate the pipes and valves. Next in turn were the enormous bunkers, tanks, water-tight doors and bulkheads, reaching from one end of the ship to the other, from the highest deck down to the bottom - most chamber of the hold. What would have hap- pened had the flashlight gone out? Would the man have fourd his way out again? to Coal wise Powder Twenty-four bombs were found in the coal bunkers. Is it any wonder the coal was screened four times? The bombs were simply tin-boxes wrapped with twine. After they were dipped in tar and rolled in coal dust they were placed with the _ coal. Each bomb was found to contain a high explosive Popular Science Monthly Getting Your Change by Machine From the Cashier a busy stores and restaurants of the pay- at-the-desk variety, a new device for handing change back to the customers is proving popular. 233 William J. Ryan, of Sapulpa, Oklahoma, has made good use of this bit of fish psychology in devising his fishing ap- paratus. He suspends an electric light and a fish hook near each other under the water. The fish are attracted to the light like moths toa flame. You simply hand in the check and the .money through the cashier’s window. When she has made the change she de- posits it in the open- ing of a cylinder, as shown in the illus- tration. By giving a slight upward push on the bottom of the cylinder you cause the two halves of the false bottom of the cylinder to open out, and the coin drops down into your palm. Or you can obtain your change in the usual way, Near the light they see the bait, investi- gate, and then re- pent when they find themselves on land. Within a wooden box large enough to hold the entire ‘ap- paratus the inventor places two batteries. Wires run from these batteries to a lamp which is suspended in the water. Rub- ber tubing around the wire keeps out the water, and so does a glass jar about the lamp. The depth of the light and the hook in by sliding it off the opening of the cylin- Above: The coin- der into your hand. Of course the device dropping device in operation. At right: will not work with The device in detail bills or soda checks. A Fishing Light to Lure the Fish to the Bait E have the word of the fishermen for it that fish are not unlike other creatures of the earth in regard to curiosity. They are as interested in what goes on below sea level in their subterranean home as we are in what takes place above it. The fish hook with its bait floats just in front of the light. The depths are adjusted by cork floats the water is ad- justed by cork floats. Need- less to say, the brighter the light the more — curious ‘and careless are the fish, all of which delights the fisherman. Guide bar limits swing \{ Slot Inner stationary cylinder Outer cylinder cam: | It Costs a Fortune to Keep French Army Officers in Cars OY riding seems to be a regular sport of French army officers. According to charges of reckless extravagance made against the touring-car section of the French army, the officers think that the cars they use are their own private prop- erty. Indeed, competition is rampant, each officer wanting the best machine and the most expensive assortment of acces- Ht Ht) 1 sories, sdys the report. The cost of twenty-six cars for the general head- quarters staff cost one hundred and seventy thousand dollars. Three thousand dollars is the annual upkeep per car. The only remedy, as France now sees it, is to refuse to allow any officer, no matter what his rank, to have a personal car. : Addressing Newspapers by the Thousands The lightning-quick method by which the news reaches the subscriber before it grows “‘stale’’ Reels of aluminum Rewinding plate spool addressing plates Rewind ding, * ribbon mS FPR TY, Printed paper ar, strip 4 Rewindin paper spool LIPARETTAD Platen oper- ating cam Printing platen tinuously. The string of aluminum plates is run at rapid speed under a wheel anvil. A stamping plate underneath. presses the paper mailing-strip and the inking ribbon against the embossed plates round the wheel anvil, thus printing one address as each plate rushes by. The result is that thirty thousand names can be printed on the paper strip in one hour. A motor-driven typewriter is used to emboss the names and addresses on- the aluminum plates. When a key is pressed, two lever arms are operated instead of the one on an ordinary typewriter. The motor at the same time presses the corresponding letter plunger and die through the plate, embossing the letter upon it. After several 3 tN , A motor-driven 2% ae typewriter em- bosses the subscri- Le bers’ names and cal. (aR al addresses on Ls aluminum plates PIP? boomy Reels of the alumi- num plates are run through the press, printing as many as thirty thousand names an hour’ ion ,lever = pie. Typewriter spacing rack embossing impress- Aluminum plate , mouthpiece of the whis- tle project beyond the handle end of the club, but they are concealed from view by acap held in position by a spring catch. If the police- man wishes to blow the whistle in an emergen- cy, he presses a push button and the cap flies back, exposing the whist]Je to view. Q48 Applying the Idea of the Needle Bath in Shell-Making HE steel utilized in the manufacture. of explosive shells must be carefully tempered. If the steel is too brittle or too ductile the destructiveness of the pro- jectile is affected. Steel of the correct temper, however, does not lend itself readily to | heavy. machine _ opera- tions. For this reason, steel shells, after the in- sides have been removed from the blanks and most of the surplus material cut from the outside, are subjected to what is called “heat treatment.” The first step in heat treatment is to bring the > shells to a comparatively high temperature. Then they are quenched, usu- ally in oil, and once more heated to bring the ma- terial to the proper condition. Although projectiles of all artillery ammunition must be heat treated, the cleverness of the French and the ingenuity of the Yankee has given manu- facturers a substitute for the oil bath which is an interesting and unusual adaptation of the familiar bath spray. The accompanying illustration could with very. little imagination be taken as a model of the original needle bath. ° The shell bath is a cylindrical, double- walled receptacle, not unlike one ashcan placed within another. The space between the concentric walls forms a reservoir for a supply of water under pressure. The inner wall is perforated, and there is also a central perforated pipe passing through the top of the needle-bath, where it connects with a piece of ordinary rubber hose. The shell to be cooled is placed in the main chamber, the perforated pipe in- serted in the nose of the shell and the water sprayed on the inside and outside of the heated case. The shell is taken for this bath from a heating furnace where it has been kept at a temperature of 1800 degrees Fahren- PERFORATED PIPE a The shell is placed in the main cham- ber, the perforated pipe is inserted in the nose of the shell and the water is sprayed from inside and outside Popular Science Monthly heit for some thirty minutes, and it remains in the bath until cooled thoroughly. Plunging the hot shell immediately into a tank of cold water after taking it from the furnace would be treatment too heroic and would without doubt do a great deal 'more harm than good; but the gentle cool- ing effect of the shower bath has proved highly efficacious. A spray of cold water seems to be as beneficial to the temper of a shell as itis conceded to be to the temper of many a fractious youngster.— REGINALD TRAUTSCHOLD, M. E. RUBBER HOSE A Fortune from Old Razor Blades CALIFORNIA man is making a little fortune out of old safety- razor blades. It seems almost unbelievable but it is not more strange than the stories we hear of fortunes made by rag- pickers and dealers in old tin cans. This man pat- ented a suitable blade- holder, which he sells with supplies of old blades to tailors, mil- liners, show-card writers, and photographers. The holder is made from one piece of steel bent in half with its two sides pressing close together. One corner of the blade sticks out from the holder. It will cut one hundred ordinary sheets of paper or a dozen pieces of cloth at a single stroke. By means of a safety holder, the blades can be used for cutting cloth, paper or cardboard 20) shee eal Popular Science Monthly When the Star-Spangled Banner Is Played Wave Your Cane Flag HE question of what to do with your cane when the orchestra strikes up the Star-Spangled Banner has been solved by Charles T. Fernandez, of Roxbury, Massachusetts. If 249 fifteen and one-half packages. In 1916 we exported 718,000 pounds—say 11,129,000 packages. We shall soon see that this is a mere bagatelle. The total amount of chicle imported, manufactured and con- sumed in the United States in 1916 was 7,031,000 pounds, equivalent to 28,- 124,000 pounds of you have one of his new canes you raise it above your head, turn a knob until an American flag con- cealedin theinterior comes out through the slot, and then wave the flag as long as the music lasts. In a word, his de- vice is nothing more than a flag wound round a roller inside the cane. The knob or head of the cane chewing gum. This represents a per cap- ita consumption in the United States of about three and a half pounds, or fifty-five packages per annum. Every man and woman, old and young, boy and girl and infant in arms represented a consumption of fifty-five packages of gum last year! Great is the power is connected with the roller so that the flag may be wound or unwound at will, appearing and disappearing through a slot. - When the flag is inserted the flag-stick fits into the cane, and the flag into the slot. Fifty-Five Packages of Chewing Gum for Everybody! T the Kansas City meeting of the American Chemical Society, Dr. Fred- eric Dannerth, of the Re- search Department of the Rubber Trade Laboratory, present- ed in detail the meth- ods for determining the content and val- ue of block chicle, of which chewing gum is made. These are of interest only to chemists, but the statistics that Dr. Dannerth gave are enough to drive us silent from sheer jaw. weariness at the mere thought of them! One pound of chicle makes four pounds of chewing gum and one pound of gum produces over Turn the knob and the flag will come out through a slot from the interior of the cane A portable nail sorter which will arrange nails and tacks according to their size of the American jaw! No wonder we are a race of orators.— ELtitwoop HENDRICK. A Portable Nail Distributor Saves the Carpenter’s Hands and His Time ~~ to the traveling carpenter, in the form of a portable nail distributor has been invented by Robert B. Holland, of North Yakima, Washington. With it the carpenter or other workman can separate small nails from large ones by simply dropping them into a hopper. The various parts of the device are easily collapsed into a com- pact package of a convenient size for carrying. To distribute the nails according to their several sizes, the nails are first placed in the hop- per and fed down- ward to the chute by jarring the casing. The nails strike the partitions and are deflected out through the openings in the bottom into the guideways. Here they collect, according to their size, and the operator grasps them by the thumb and forefinger. : | Conquering Your Cramps Under Water Some valuable first-aid advice from the champion long distance swimmer of the world Below: Henry Elionsky swam from Battery Park, New York, to Coney Island, with hands, feet and legs shackled. Time 5 hours, 20 minutes. His sister, with hands and legs free, ac- companied him. Here they are. diving from the Battery pier Tt atee © Certeo] Neovws Breaking the arm cramp by sheer strength. The lungs are first filled with air to prevent panic; then the arm is forced out straight HE “Old Man of the Sea,’ who figures in fiction so mysteriously and with such dire consequences, might well be named ‘“‘Cramps’’ for everyday application, as far as swim- mers are concerned. To many swim- mers, otherwise absolutely fearless in the water, the suspicion of a cramp is a nerve-wrecker. But, according to Henry Elionsky, holder of the world’s long distance swimming champion- ship, that is because they do not em- ploy the scientific method of breathing when in the water. The rule which Elionsky gives to his pupils at the Brighton Beach Baths near New York is: “‘When in the water breathe through the mouth only and gulp the air, as you would if you were frightened or very. much amazed on land.’ The air thus in- haled is driven into the lungs in about five times the quantity rate breathed through the nose. A cramp is merely a contraction of the muscles caused by the penetration of the cold. Obviously, it could not of itself cause drowning. Its worst effect is to cause a panic which throws the swimmer off his guard, causing him to let the air out of his lungs and thus allow the air passages to become filled with water. The safeguard against such a panic is absolute confi- dence in the floating power of the | . body and a demonstrable knowledge Forcing a cramped leg straight. The body will of the proper way to quickly fill float as long as the lungs are kept filled with air 250 Popular Science Monthly the lungs to utmost capacity with air. The moment a cramp is felt, the swim- mer should turn on his back and begin to gulp the air, making no effort to keep himself from 251 pairs, the wheels of each set being coupled together and driven by two giant steam cylinders. Under full steam, the locomo- tive can exert an eighty-three ton pull on the cars behind sinking. As he sinks he slowly exhales under water, through the mouth, with the lips puck- ered as for whistling. If it is a stomach cramp the knees will be drawn up against the abdomen, but the swimmer should force them out, push- ing on them it—which means that it can easily haul a freight train two miles long and twenty- three thousand tons in weight over an _ ordi- narily good road-bed at an average rate of about fourteen miles an hour and possibly with both hands and us- ing all his strength until they are fully extended. This will no doubt cause great pain for a few seconds, but as soon as the legs are straightened out the cramp will vanish, and the body, buoyed up by the air in the lungs, will shoot up to the surface. There, still inhaling in great gulps and ex- haling through puckered lips, the swimmer may float until he re- gains his strength or is picked In case of cramp in the leg or arm the same system of breathing is followed and _ the affected part is straight- ened out by sheer strength. The Very Biggest Loco- motive in the World HE greatest steam loco- motive in the world has been. put into service by the Baldwin Locomotive Works. It is so gigantic that its boiler had to be made flexible at three different joints so that the loco- motive could turn around a curve! It is over one hundred feet long and weighs some four hundred and twenty tons. Twenty-four driving wheels, each standing as high as ~ an average-size man, afford it traction. The driving wheels are distributed along the length of the locomotive in sets of four The flashlight bulb is clipped to the end of the handle of the safety razor and throws the rays across its path more. Bad roads will re- When the cramp is in the stomach, turn on your back, tard it only gulp the air to fill the lungs and push the knees down slightly. Shave Under a Flashlight Attached Directly to Your Razor “L,IRST AID” in affording yourself a quick shave is given by a new razor attachment patented by Katherine E. Allport of Chicago. It is a com- bination of a flashlight and a razor which will illuminate a man’s face far better than the regular wall light. A wall light which is di- rected upon one half of the face cannot intensely il- luminate the other. But by having the light attached directly to the razor, the light follows the blade and ‘the strong rays are thrown just where they are needed. The chance of cutting yourself is thereby reduced considerably, and a perfectly clean shave is assured. The small flashlight bulb is clipped with its socket on to the handle end of the razor. The conducting wires from the sock- et lead to small dry cells which occupy the bottom half of the razor_box especially built for this attachment. From one to three dry cells can be employed, depending upon how much light you con- sider necessary for the operation. : Q52 Popular Science Monthly thousand dollars to carry out her father’s wishes. The model is com- plete in every detail, even to small whale boats which hang from’ the. davits. It measures fifty-nine feet from the figurehead to the stern, and it is eighty-nine feet from flying jibboom to spanker boom. The cost of the model alone was twenty- five thousand dollars. The Curious Ways of Egypt’s. Holy Beetle HE holy beetle of the Nile is found carved in stone every- where in Egypt—a relic of a time — when crocodiles, bugs, and beetles were objects of worship. As the scarab is a dung beetle it is naturally found in the vicinity of herds and particularly in pastures where no- madic herdsmen watch their flocks. The scarab is not satisfied with merely eating manure on the spot, as are most dung beetles. It fashions perfectly rounded balls out © Brown and Dawson . A life-size model of the whaling ship, Lagoda, which was built in the room in which it is exhibited The Largest Model of a Ship Ever Constructed Under a Roof ie the days when the American merchant marine was the pride of the entire shipping world, New Bedford, Massa- chusetts, was the port of many a prize- winning cutter. It was also the headquarters for the whaling industry. One of the early sea captains who made a fortune out of whale oil: was Jonathan Bourne, whose fa- vorite ship was the Lagoda. When Jonathan Bourne died he or- dered a model of the Lagoda—the largest model of its kind in the world—placed in a museum known as the Jonathan Bourne Whaling Museum. His daughter, Emily of manure and rolls them often con- siderable distances and buries them in the sand. These dung balls serve the scarab and its brood as food. It makes several balls for itself, and others similar in appearance for the brood. All are buried in the sand. When making a ball for the young the beetle is exceedingly careful in the selection of food. It rejects all un- digested vegetable particles. The ball is fashioned into pear-shape after having been placed in the ex- cavation made to re- ceive it. A single egg is laid in a small receptacle in the elongated part of the pear. The larva, slip- ping from the egg, eats out the interior of the greater part of the ball, leaving a hollowed-out portion inside of the hard outer crust. Within thisshell thechrysalis stage is then passed. Howland Bourne, contributed fifty The scarab rolling a ball of manure many times its own size to a suitable hiding place —Dr. E. BADE. Popular Science Monthly 253 With an Axe and Two Springboards He Studying the Effects of Calf-Foods by Chops His Way Up a Giant Tree Means of Photographic Records ROM the logging camps in the vast N keeping records of experiments to de- timber district of Vancouver have termine the effects of various foods and come some remarkable accounts of dar- combinations of foods as substi- ing and agility. The story that is going tutes for whole milk in the rearing the rounds of the camps just now is the of calves the Agricultural Ex- tree-climbing feat performed by a power- periment Station of Purdue ful lumberman, Andrew Busby. A University, Lafayette, cable had to be attached to a tall Ind., uses photographs tree at a point one hundred and instead of tabulated twenty feet from the ground. figures to furnish an With pole-climbing spurs and index in regard to the belt this would have been a condition and develop- simple task, but no such equip- ment of the calves. ment was available. How was The photographs are made at it done? intervals of thirty days during With an axe and two spring- the first six months. The illus- boards Busby began to climb tration shows the equipment the tree. Using the first used in securing the pictures. board as a platform he The background is divided. into chopped a notch five feet six-inch squares to designate the above him, slipped the height and length of the calf. second board into the In order to secure contrasts in notch, climbed up, and, the photographs of calves of pulling the first board different breeds, a black or a after him, continued the white background is used ac- operation a _ score of cording to the color of the calf. times. Within an hour The camera is placed on a he stood on the last stationary support and is situ- springboard, at the top ated at a uniform height and of the tree, and affixed distance from the background the rope, his companions for each exposure. No special yelling their admiration attention is given to the calf in the meantime. Standing more than a_ on the day it is to be photographed, so that hundred feet above the ground on a little the picture may represent its ordinary ie, With an axe and two springboards Busby climbed to the top of a 120- foot tree cutting grooves into which to insert his board at five-foot intervals platform a few inches wide he was ap-. condition. When all preparations have parently as calm been completed as he was when ——e = s for the picture on the solid. “Scena — the calf is led up ground. to the platform Needless to say, Busby is an expert chopper, in front of the , chart. When it . reaches the cen- SPR B4 90.2 seen skilled in the use of the spring- board and is pos- _ sessed of the fear- lessness natural to the woodsman. His claim to the title of champion tree-climber has not yet been dis- puted nor is it likely to be, ac- cording to his fellow workmen. 26S 2 8.6 ss phe x % “ae ej ee) a ed The calf is photographed against a squared background at regular intervals to obtain records of its growth ter of the plat- form a helper on ‘the other end waves a cloth or coat in front of it, just enough to cause the calf to pause and con- sider whether it is wiser to go for- ward or back. During that second the cam- era clicks. : 254 Populie Séionéa Moreida switch, the director can hear the orchestra and the soloists as well as if he were one of the audience. When a certain motion picture is scheduled on the screen, the director connects up _ the speedometer near him with the motion picture projector in the gallery. This meter is similar to those used on automobiles, except that it indicates feet of film per second instead of miles per hour. Hence, the director instantly can find out when the operator fails to run his picture at the proper speed. The opera- tor can then expect to hear from the ~ Mr. Harold Edel, Managing Director PROJECTION ae director—who of the Strand Thea- ter, New York city, attending to busi- ness in his office and following the progress of the show at the same time. At right is shown the details of the electrical devices by means of which the director can keep in touch with the stage and audience Directing a Motion Picture Show From the Manager’s Office the audience and the stage while GENERATOR [ VOLt — feo | TRANSMITTER IN FOOTLIGHTS © SPEED INDICATOR merely speaks into the telephone trans- mitter mounted in the same box as the detectaphone re- ceiver. By means of this same trans- mitter the director can get in touch with any part of his theater when giving his orders to “‘ginger up” the show. The Evaporation. of Water Drives This Remarkable Clock German watchmaker, is run by ether HE problem of keeping in touch with A CLOCK designed by M. Bernardi, a attending to the affairs of his own and water. The driving wheel private office, has been solved in a very Twentieth Century way by Mr. Harold Edel, managing director of the Strand Theater, New York City.. He sits in his office physically; he sits with the crowd electrically. Adetectagraph leads from the footlights of the stage to aloud-speaking receiver mounted in a box on the manager’s desk. This transmitter is like the concealed tele- phone instrument by means of which detec- tives listen to the con- versations of criminals. The waterworks of the clock depend upon the evaporation of the water By the throwing of a and the expansion of the ether vapor ball rises. consists of three glass tubes having light glass balls fused to.their ends. Some ether vapor is contained in each tube system. The water is contained in a_ reservoir, through which the balls pass when turning. An outside covering of cloth on the balls carries up a film of water when the balls turn out of the reser- voir. When water begins to evaporate the tempera- ture lowers. This lowers the pressure within the upper balls. The ether vapor in the lower balls rises upward as each cooled 4 j Popular Science Monthly A Puncture-Proof, Bullet-Proof, Blow- out-Proof, Skid-Proof Tire ROM Washington there comes the photograph which is reproduced here- with, showing a Seattle citizen’s ideas on keeping pneumatic tires out of harm’s way and yet getting a little more service from them than could be obtained if they were locked up in a dark room in an atmosphere of nitro- gen. To accomplish his pur- pose the inventor uses 100 to 150 pounds (estimated) of a “special grade steel” foreach ¥ tire, which might seem ex- § cessive to the ordinary § ™ mind, but, having done so, he has the satisfaction of \ | announcing that the tire by \ this heroic means is rendered non-skid, puncture-proof, bullet-proof—‘‘of great bene- fit to the warring countries’’— stone-bruise and blowout-proof and is endowed with four ordi- nary rubber-tire lifetimes. In- cidentally, in case that anybody should venture to place a wagon- wheel steel tire in bold competi- tion with his invention, he assures you that it will wear out three such, this referring perhaps mainly to a special type of his pro- tector which he has taken the extra trouble of devising for ‘‘un-inflated’’ rubber tires. y > aw Encased in this armor a tire should have a chance to die of old age 255 The question arises: Given leeway to use 100 pounds of extra material, could a tire- maker produce anything better than this protected tire? The inventor apparently challenges them, one and all. He bravely uses thirty-six steel spacers draped around the tire six inches apart, and on this for- midable base he strings about thirty feet of heavy coil springs and forty feet of lighter grade, whereas one lock, three clamps and twelve rods with threaded joints serve to hold the armor so formed tightly against the heaving breast of the poor tire, ordinarily so much abused. Springs are springs, he reasons, and keep the natural resilience of the tire unimpaired, even if expected to work crosswise. Careful inspection of his photograph reveals, however, that steel rope is used instead of the lighter coil spring along the least visible portion of the cir- cumference, but this is ap- parently an emergency arrange- ment for publicity purposes only. How Monterey Turned a Whale into One of the City’s Sights © Int. Film Serv. The spinal column of the whale mounted for exhibition at There are fourteen ribs Monterey consists of forty-six sections. ONTEREY, California, has solved the question of what to do with a stray whale that is washed up on shore. After disposing of the flesh and oil to a refinery, the bones may be mounted on shore and kept as a permanent natural history exhibit. That is what the city officials did with a whale which was washed ashore there. It was welcomed with open arms and the bones were saved as an educational feature for the benefit of the school children of the city and for interested adults. Since there was no _ build- ing available large enough to accommodate it, it was set up in an open lot and fenced in. What’s On the Moon? Look through the telescope with us and see the great mountains, the vast dead craters and arid wastes of slag By Scriven Bolton, F, R. A. S. Illustrations specially prepared for Popular Science Monthly by the author UCH is the power of our largest tele- scopes that a creature as large as an elephant might be detected on the moon. Hence we are more familiar with the lunar surface than with Central Africa. Since there is no appreciable air on the moon, our view is always clear and un- obstructed. Why has the moon no atmosphere? Simply because the force of gravity is so small. The weight of an object on any planet -depends upon the mass of that planet. On .Jupiter, the largest of all planets, you would have difficulty in lifting your arm from your side. On the Sun you would probably. need a steam crane to help you move about. On Mars you could jump over a small house. Small planets, including the earth, are gradually losing their atmosphere. The smaller they are the more rapid is that rate of loss. since the moon is very small, it lost its atmosphere long ago. Thus is to be ex- plained the fact that the earth is still wrapped in air although the moon, child of the earth though it is, is airless. Because of this entire absence of air astronomers consider it improbable that there is any lunar life. Perhaps there.may be rem- nants of vegetation within certain low- lying craters and in the deepest valleys and chasms where a few shreds of atmos- phere may still pervade. But nothing of the kind has as yet been detected, and as we gaze in bewilderment into every crack and crevice of the surface we rightly conclude that the moon is a truly barren world. On Top of a Lunar Mountain Although we cannot fully realize existence on the moon, it is nevertheless the inevitable experience of the astronomer when tele- scopically raking the lunar surface with what might be justifiably termed an eye of the earth to identify himself to such an extent with the scrutinized scene that he ofttimes unconsciously thinks himself a lunar inhabitant. It really requires but little imagination to suppose oneself actually planted among the lunar craters and And __. mountaifs, viewing in awe the wonderful landscape. Now let us endeavor to realize, by the help of the accompanying illustrations, that we have taken our stand upon one of the mountain peaks such as we see in these pictures, and by commanding an extended view of the surroundings we duly note the strange lunar conditions produced upon the landscape. Dawn Is as Harsh as Midday The lunar day is thirteen times longer than ours. Dawn, in an earthly sense, is unknown, for there is no atmosphere to reflect the solar beams while the sun is yet below the horizon. The terribly harsh solar beams suddenly appear on the black horizon, dazzlingly illuminating the moun- tain crests, while the valleys are still in utter darkness. Because there is no atmosphere, blending of the night into day at sunrise is unknown, and all the gorgeous tints which attend a terrestrial sunrise are on the moon quité absent. . On earth we are accustomed to see the sun’s light softened by an air screen. The fierce splendor of our luminary on the moon, however, is rendered more obvious by the blackness of the sky, owing to the absence of air. Even in broad sun- shine the sky is as dark as our darkest star- light nights, with the stars and planets shining more brightly than it is possible to see them here. The appendages to the sun, such as the Zodiacal Light, the Corona, and the red protuberances, appear in glorious perfection. What a magnificent object is the earth, thirteen times larger than the moon appears to us, and practically stationary in the heavens! It exhibits phases precisely as does our moon, the interval between each full “earth” being about twenty-nine days. The sublime and periodical spectacles of a total solar eclipse and an eclipse of the “earth” are attended by circumstances far more imposing than their earthly counter- parts. The spectator sees the earth-globe rotating on its axis, the continents, oceans, and polar snow caps being well displayed. Portions of the surface appear inter- 256 62 en ef 62 <2 C2 62 2 62 Vv . | | | | | How the “Full Earth” Looks from the Moon The long lunar night, which comprises thirteen of our nights, is substantially relieved by the reflected light of our globe, which at full “‘earth’’ radiates thirteen times more light than the moon does tous. The landscape depicted here is characteristic of many regicns on the moon, showing the surface strewn with volcanic craters varying in size from a few hundred feet to many miles in diameter, some possessing a central cone. The moon swarms with these objects > ; TT An isolated mountain at the north terminus of the Apennines. Popular Science Monthly Rising 15,000 feet goes the plain it is but one of scores of similar solitary peaks, the sublime grandeur of which cannot be overestimated. Even at midday the sky is darker than on our darkest starlight nights, with the stars and planets shining brighter than it would be possible to see them from our earth mittently obscured by slowly-moving white vapor in the terrestrial envelope, lying usually in long streaks roughly parallel to the equator. The Terrible Desolation of the Moon And now assuming that we have planted ourselves upon a more elevated portion of the moon, our attention, which has been directed to the sky, is now concentrated upon the surrounding landscape. We be- hold everywhere a scene representing the wildest desolation. The shadows assume total blackness and appear quite im- penetrable to one’s vision; for absence of an atmosphere means no diffusion of light. In stepping behind a bowlder or any other part which does not receive the direct rays of the sun, one becomes invisible. Volcanic cones, ranging in diameter from a few hundred feet to many miles, literally crowd the surface as far as the eye can reach. At a distance of forty miles or so the summits of a gigantic mountain range are seen peering above the horizon, and as clearly defined as the adjacent neighborhood. It is difficult if not nearly impossible to pass correct judgment on the distance of the various features owing to the lack of aerial perspective. The region close by is seen to be composed chiefly of hills of volcanic debris, rocks, bottomless pits, yawning crevasses and piles of slag—doubtless scene of inconceivable commotion in ages antedating mortal history, but now a world devoid of sound or disturbance, and minus evidence of organic life. Indeed we realize that we are in touch with a world which is typical of a dream of lifelessness, an apparition denoting not death, but a world upon which life has never appeared. No atmospheric elements have been at work to tarnish the pristine hues of many parts Popular Science Monthly ti Z wis Mlsasdbediliip alii Wee The Valley of the Alps. wide at its broadest part. This flat-bottomed valley is over 70 miles long and is about 6 miles It is bordered by majestic and precipitous mountains, the peaks of which attain an altitude of 9,000 feet above the valley. as shown in the foreground, indicate piles of slag. Rugged hills in the immediate vicinity, A scene of dreary desolation, even with the noon sun shedding its overpowering light, although at some very remote epoch one of incon- ceivable commotion. which bear every evidence of having passed through a fiery ordeal. The entire surface is one of dreadful contrast; the dazzling brightness of the landscape compared with the hard black shadows; the black sky, even at noon, with the sun shedding a ghastly overpowering light; these condi- tions, together with no trace of life, form a scene of dreary desolation, but nevertheless one of sublime grandeur. The Deathly Silence of the Moon Although the sun pours his heat upon the surface throughout the long lunar day, which comprises over three hundred of our days, yet the rocks remain too cold to touch with safety. . Everywhere there reigns the silence of death. Occasional landslides, cracking of the surface and shrinkage commotions, dislocation of piled up volcanic debris, all occur without an attendant sound. Because there is no air The entire region appears to have passed through the fiery furnace we cannot hear. Ten thousand volleys might be fired instantaneously, with a resultant vibration of the ground, but the prevailing silence would remain unbroken. It is indeed a world possessing conditions just the reverse of ourown. Imagine there to be no water, no air, nothing to sustain life for a single instant! We see a world of mystery and destruc- tion, riddled as is its surface with volcanic formations representing primeval forces, but maintaining their original charac- teristics and freshness owing to the absence of disintegrating elements. Nevertheless, it teaches one grand lesson in that it “exalts our estimation of this peopled globe of ours,’ writes Carpenter, ‘by showing us that all planetary worlds have not been deemed worthy to become the habitation of intelligent beings.’” So we mentally ‘come back to earth,’’ perfectly content to have taken only an optical flight to the moon, ; Any venturesome flies seeking to enter when the door is opened will be blown away by a blast of air from the fan Keeping Out Flies When You Open the Door DOOR-OPERATED fan which drives away venturesome flies has been brought out by Joel J. Hurt, of South Omaha, Neb. The bracket holding the fan is attached to the door jamb at the top of the door. The gear of the fan en- gages the driving gearing mounted on another shaft. This driving-gear shaft car- ries a small pulley on its lower end. A flexible cable wound upon this pulley is attached to the door. When the door is opened the unwinding of the ca- ble operates the fan. The gearing is made high so that the fan is whirled rapidly. An automatic clutch disconnects the fan from the pul- ley when the door is fully opened. Mo- mentum keeps the fan rapidly turning until the door is closed. A_ strong spring, which was wound up with the — Popular Science Monthly If Your Parrot is Thirsty, Give Him a Drink HERE is a curious superstition ex- istent among parrot-keepers,” says L. S. Crandall, in Pets (Henry Holt & Co., New York), “to the effect that these birds not only require no water but are better off without it. The foundation for this absurd belief is not hard to find. When parrots, particularly young birds, are being brought from the tropics, they are custo- marily fed on boiled corn or bread and milk. What moisture they require is ob- tained from the food. If such birds are suddenly given access to unlimited water, the effect on the digestive organs is danger- - ous, and may result in the death of the bird. On the other hand, if the parrot be given a drink daily, and then the water be re- moved for a short period, the bird will gradually become accustomed to it. Once this is accomplished, there is nothing to fear from clean water.’ An Accommodating Church—It Goes Wherever It Is Wanted N India and in some places of the New ‘World, particularly in the British West Indies, many religious festivals are held along the roadside and in the open fields during the month of February, which is the month of weddings and special feastings. On such occasions the participants in the ceremonies do not go to church. The church comes to them. Ornate struc- tures of papier maché are used for the purpose, and these traveling temples are drawn through the streets and country roads by religious devo- tees, who will stop when called upon and hold a service or deliver prayers for a small sum. Such temples take a conspicuous part opening of the door, causes the door to close automatically. India. Carrying the temple through the streets of During the month of February it is in great demand for wedding celebrations in all parades and religious celebra- tions, Popular Science Monthly One Horsepower Will Run All the Watches in the World N astute French mathematician has found that in certain watches the motions exceed two hundred million a year in little equal jumps. In the same time the outside of the average balance travels seven thousand five hundred miles. Yet despite this astonishing distance traveled by the ordinary watch the amount of power con- sumed is trifling. One horsepower is sufficient to run two hundred and seventy million watches. This is probably all the watches that are in existence. But if there should be more there would be enough power left in the one horsepower to run an additional thousand watches or so. A The Latest Conceit in Timepieces Buttonhole Watch ie spite of the fact that there is no article of jewelry more useful than the watch, it seems hard to stow it away in a suit of clothes. It has been tucked away in vest pockets and belts, attached either to an ornate chain or an inconspicuous ribbon, and has adorned the wrists of all classes. But the very latest and most con- spicuous location yet chosen for it is in the buttonhole of a coat lapel. The buttonhole watch is nec- essarily tiny, and fits into a gun metal case which re- sembles a large-sized collar button in shape. When worn merely for the con- venience of the owner the watch is_ usually turned upside down so that the time may be seen at a downward glance, without even lifting the lapel of the coat. It is said that the diminutive size of the watch does not interfere with the accuracy of the works. The principal ob- jection to wearing one of them just now is that the buttonhole is needed for flag emblems and liberty bond buttons. The buttonhole watch fits into a case resembling a large-sized collar button A self-contained motor-truck equipped with standard electric street car trolley pole and a storage battery Making a Trolley-Car of the Motor-Truck HY can’t motor-trucks and other commercial vehicles obtain their power from overhead trolley wires? So they can, if reports from Bradford, England, are true. In Bradford a motor-truck with a trolley pole attached to its cab takes power from overhead street car wires. The truck runs along on the street-car tracks, contact with: the rails being made by means of a cast- iron block to the steering gear. This block also steers the vehicle. When the truck reaches the end of the street-car tracks, the rail con- tactor is lifted, the trolley pole pulled down, and the stor- age battery 1s brought into action. The truck then con- tinues on its way asa self-contained vehi- cle. The motors are of twenty horsepower. The battery is arranged so that it can be charged with street car current when the truck is run- ning. On one charge of the battery the truck can run for about ten miles. 7 262 Device to Remove Automobile Bodies | Without Scratching Them ‘WO men can remove a highly-polished automobile body from its chassis without giving its surface a scratch, by means of the device shown in the accom- panying illustration. This new device is attached to an over- head trolley. It con- sists of two sets of compass-like arms pivoted to the ends of a common cross- member at the top. The arms of each set may be spread out to reach the front and rear ends of the body in exactly the same manner as a compass is opened by At left is a diagram of the lifting device Set screw # \ set oes Adjustable support means of a rack and quadrant device. Each of the arms is made with a telescop- ing bottom for adjustment to the various types of bodies. Loose collars with two projecting arms are slipped over the bottom of each arm to reach underneath the side of the body and support it at unpolished points. The looseness of the collars enables them to be turned in any direc- tion or moved up or down to obtain the proper point of support. In operation, the framework carry- ing the lifting device is moved along its trolley so that the compass arms are on each side of the body to be lifted off the chassis. The arms are then spread out and the lifting collars adjusted and inserted under the body; after which the entire device is raised vertically by means of a chain block,’ until the body clears the projecting Lifting an automobile body off its chassis by means of compass arms on a trolley Popular Science Monthly levers. It is then moved horizontally to its point of deposit. The reverse of this operation puts the body back on the chassis. : Sometimes the body must be lifted clear _off the chassis frame for a height of two or three inches before the projecting arms on the lifting collars can be placed on some unpolished part. This may be accom- plished by means of a two- part bar with beveled ends, which bar is held together at the center by means of a collar or sleeve. By removing the floor- boards of the car body, the beveled ends of the bar may be inserted between the bottom of the body sill end the frame. An Automatic Revolver No Bigger . Than Your Watch UTOMATIC revolvers are made about as big as a standard watch. Little as these revolvers are, they never- theless contain an automatic reloading mechanism as complete as that of any of their bigger brothers. They are “‘seven- shooters.’’ Six cartridges are held in the magazines in the handle, and one in the firing chamber. The pressing of the trigger sends the firing-pin against a tiny percussion ‘cap. The bullets are one-tenth inch in diameter and weigh 1/100 ounce. In a half inch of space across the breech, this revolver contains a complete automatic reloading mechanism Popular Science Monthly A Small Sand Spreader Is Useful . All the Year Round HE small two-wheeled bin device shown below is particularly adapted for spreading sand over small areas such as icy cross walks in the winter or over oily streets, or for scattering fertilizer in the summer. The sand is spread uniformly with no bare spots or large piles, hence this is preferable to the hand method. The device is alsoapplicable to the spread- ing of ashes over country walks. The apparatus con- sists of a funnel-shaped bin mounted on an axle with two wheels and provided with front and rear handles so that it may be pushed along from either end. A vertical rectangular open- ing is provided at the bot- tom of the bin with a slide- door through which the sand or other material to be spread drops upon a circu- lar horizontal plate held ina vertical shaft on a frame attached to the axle. The circular plate is directly beneath the bin opening and is provided with curved radiating fins. The plate is revolved at a speed varying with that at which the cart is pushed by means of. a set of bevel gears and a chain driven off a large sprocket on one of the wheels. The sand dropping on the plate is thrown off by centrifugal force when the plate auto- matically revolves as the cart is pushed along. In this way the sand or fertilizer, or whatever may be the contents of the bin, is distributed evenly whether the cart is Peushed slowly or rapidly: The funnel-shaped bin with its circular plate underneath, spreads the sand automatically A child can drive this ingenious vehicle with one hand. The diagram at the right explains the principle involved 263 The Newest Child’s ‘‘Pushmobile.”’ It Is Built on a Novel Principle CHILD’S hand-propelled pushmobile has been invented by Charles R. van Horn of Aberdeen, Wash. The lower end of the operating lever is coupled by two connecting rods with the gearing that drives the rear wheels and propels the vehicle. The connecting rods are attached to the lever at different points; they also engage the first gear wheel at different portions. Hence, any dead center is eliminated. Whatever its position, the lever will immedi- ately start the vehicle when any pres- sure is eeeree on it. Steering wheel ~~ Propelling lever Double lever to eliminate dead center / Steering wheel Drive sprocket A child can drive this machine with one hand. The steering is controlled by a rotatable handwheel mounted on the pro- pelling lever. Two flexible cords connect this steering-wheel with opposite portions of a cross member attached to the mounting of the front wheel. The propelling lever is not tilted from side to side like a tongue but always moves in a straight forward-and- back direction lengthwise of the platform of the pushmobile. In fact, this steering wheel is operated likethatof an automobile, so that the child in learning to drive the toy. push- mobile is really trained to govern a big car. For coasting, the gearing can be shifted out of operative connection with the propelling lever, the coasting device being regulated by the child’s foot. As an exerciser, this form of vehicle leaves nothing to be desired. Practically every muscle of the child’s body is brought into action—notwithstanding the fact that the operation is smooth and easy. Naturally, the faster one wishes to go the more effort must-be expended. ke tai i Washing the gold-containing gravel through a sifter which serves at other times as a hat ‘Panning for Gold in Central and South America HE “‘battel’’ used by the prospector for gold in Central and South America in tropical placer mining is a better gold- saver than the Alaskan gold pan. Shaped like a platter, with a Popular Science Monthly Everybody Is Acquainted with the Squash Bug Sou of us know all the bad things about the squash bug—that it is proverbially ill-favored and_ ill-smelling and an enemy to the squash vines. We have heard the entomologist speak about Anasa tristis with elaborate description of the bug that hibernates in the adult stage, wakes up in the early spring and lays its eggs on the young leaves of the squash and the pumpkin. We think of it as we think of a pest. From the human point of view it is a pest, but it improves on ac- quaintance. It is true to its family char- acteristics; it is really a bug; it isa member of the family Heteroptera, and is somewhat of a beauty (we mean the “‘lady-bug’’). In the accompanying photograph the protruding part of the sheath is the tongue or sucking beak. The squash bug’s eyes are large and beautiful, and really wonder- ful when seen under a microscope. The antennae or feelers, the two branched prongs between the eyes and the tongue, are marvelous organisms of sense. It would be difficult to enumerate all their duties, not because the list is long, but because we do not wholly know what those duties are. They surely enable the bug to recognize its surroundings; what depressed center coming to a point in the middle, the gold collects in the point of this broad shallow cylinder. The pan is filled from a pool with gold-containing quartz gravel and is rocked in the ortho- dox manner. As the pan rests on the bot- tom the contents are tipped and swirled about until the dirt loosens and only the pure gravel and hard substances remain. Of these, only that which is bright yel- low is valuable. When the miner is not sifting gold with it he uses his battel as a hat.— GRACE S. MATHEWS. Som: Portrait of a squash lady-bug. else they do is be- yond our under- standing. But the most beautiful of all its anatomy is the curi- ously mottled sheath ‘that covers the head and the thorax. These dots bear a high magnification, and the better one knows them the more does he admire them. It is indeed a marvelous object. It is astonishing that there should be so much beauty, so much elaborate structure where they seem misplaced so.far as general | human apprecia- tion is concerned. —EpDWARD F, BIGELOw. The protuber- ances at the side of the body are the eyes Popular Science Monthly Giant Mushroom Anchors for Holding Buoys ~ ed USHROOM” anchors take their name They look like from their shape. mushrooms upside down. The mushroom anchor illustrated was made by a prominent cast-steel maker of this country for use by the United States Department of Commerce in lighthouse service for buoys. Those of this type weigh 5000 and 7000 pounds each and are made entirely of cast steel except the shackle pin. They are practically one piece. The buoys are attached to these. The anchor holds the buoy in the location desired. The test to which these ‘anchors are subjected be- fore acceptance by the Government is extreme- ly severe. Each anchor is dropped on a steel block from a height of twenty-five feet. Should a fracture of any kind appear as a result of this test the anchor is rejected. ~ Formerly these anchors were made of cast iron but the Government’s requirements now demand steel because of, the severe treatment to which they are subjected in rough weather. The Rate at Which Food Prices Have Advanced OW much has the cost of food ad- vanced? According to one of the leading statistical houses of America, cab- bage has gone up 850 per cent since last year; onions, Mushroom anchors are used in the lighthouse service to hold buoys in place. tain from 5000 to 7000 pounds of steel each 265 The Compressed-Air Orchestra: Human Lungs Give Place to Tanks F the inventors have their way, musicians will no longer need to blow their souls into their instruments. The inflated . eye-ball, the puffed cheek, and all the laugh-inducing mannerisms of the men who play the wood and brass instruments will become as history. The flute will chirp, the saxophone grunt, the bass horn growl, without a musician’s mouth at a single instru- ment. Human lungs will not be need- ed; compressed air furnished by a mo- tor and a pump will take their place. The air, after being stored in a tank, as shown at the right of the illustra- tion below is led through a pipe to the music stand and thence through an air tube to the mouth of the instrument. The musician takes his accustomed place in front of his instrument, with his foot on the air- control pedal at the bottom of the stand. He plays with his hands and one foot. The air- control pedal works like the accelerator of an automobile engine; it enables the musician to accurately regulate the supply of air at all times. The inventor does not make any pro- vision for tone shadings. Although he can regulate the supply of air he can not give delicate gradations of expression. Conse- quently, music from instruments played by compressed air will be more or less mechan- ical. Moreover some brass and wood instruments must be played by living men, because the notes are formed by the lips. But for certain well-defined purposes and in places where the audiences are not over-critical They con- i;FOO per cent; pota- toes, 280 per cent; eggs, 77 percent; beef, 20 per cent; pork, 70 per cent; butter, the compress- ed-air orches- tra, will prob- ably prove as popular as the mechanic- ally operated piano. In this way one musician can operate rtan ea Automatic. shut off 30 per cent; dic contra wheat and Mec ———————————— flour, 46 per cent; beans, The brass and wind instruments in the orchestra are played by go per cent. compressed air instead of lung power and operated by one man severalin- struments. Five ‘Tools in One Here is a combined spade, knite, pick- axe, hammer and trench weapon TOOL which permits of a wide A variety of uses has been invented by Dr. F. P. Archer, of Wilkes-Barre, Pa., and could with advantage take its place _ beside the other necessary equipment of the fighting man. A modern army must not only be equipped, each man individually, with practically every necessity for fighting and for health and comfort that space will permit, but it must be equipped with tools to dig itself into the ground when necessary. The tool invented by Dr. Archer may be used as a spade, a knife, a pick-axe, a hammer and a weapon for hand-to-hand fighting or trench raiding. The blade of the spade is carried in a pocket across the breast, as shown. Carried in this position it is a shield protecting more than twenty- five per cent of the vital anatomy of the wearer while facing an enemy bayonet charge. On the other hand, it is made of chrome nickel steel so tempered that it will resist a service Here the combination tool-weapon-shield is a peaceful-looking hammer-headed spade rifle bullet at two hundred yards and will be ample protection from a forty-five caliber revolver bullet at close range. The entire outfit, including the pocket, weighs only four and one half pounds. The spade shield is the heaviest part of the equipment. The spade blade. can be attached to the handle of the tool , without screws or bolts or sma Tl parts. shield. place. At left the tool is tucked away in its pocket where it serves asa In the center the handle is in use with the hammer head in At right is shown how the i spade is adjusted without screws _ < : = or bolts’ by sliding it on the rod — 266 Popular Science Monthly Coaxing Music from a Pile of Rocks MR. FROST, of Mar- blehead, Mass., was en- gaged in clearing his land of some huge, flat rocks, when he accidentally struck one with his hammer. It emitted a clear musical note. He struck another in the same way. The tone given out was equally clear and sweet but different in pitch. Trials with other stones of different shapes and _ sizes convinced him that it was possible to arrange the stones so as to get the notes of the scale. After various experiments he piled the stones as shown in the accompanying photo- graph, securing thus a primi- tive instrument that any cave-man might have envied. Household Bookless Bookkeeping on the Poker-Chip Principle NEW system of bookless bookkeeping, designed especially for the housewife, happily coincides with the demand for careful record keeping in order to cut down expenditures to a wartime basis. This new system substitutes for old fashioned juggling with figures the simplicity and vividness of account-keeping with poker chips. With the new method, books are entirely eliminated. The equipment con- sists of a box containing twenty- eight compartments to show ex- The “piano” made of a heap of stones jarranged so that the tones of the natural scale are produced by hammer-blows each item by counting the amounts in the different compartments. If the article is charged, the right amount is placed in the proper compartment, and a corresponding amount in the ‘“Charged”’ compartment. Thus there is a correct tab on the amount owed as well as on the expenditures. After the housewife has determined by a two or three months’ trial about what her normal expenses are for the various items of expenditure, she may change to the budget system. Slips totaling the proper amount are placed in the various compartments, and, as expenditures are made, the amount is removed. The slips remaining show at all times the sum left in each ‘‘appropriation,” penditures for groceries, meats, milk, butter, eggs, and other items of house- hold expense, and seven additional com- partments to hold slips representing various denominations from ten dollars down. When a purchase is made, slips indicating the amount are placed in the appropriate compartment. At the end of the month,. the housewife can determine the amount spent for so that economy or The bookless bookkeeping outfit for the housewife who dislikes keeping accounts freedom in spending may be observed. If the slips in any com- partment run short, others may be “bor- rowed” from a com- partment with a sur- plus, a ‘“‘due’’ check being put in to show the indebtedness. The amounts remain- ing at the end of the month indicate the sur- plus, and the due checks shortages. Thus all figuring is eliminated. 7 Smoke inlet valve Device for forcing smoke through tube Smoke outlet valve The dummy smokes a real cigarette in a realistic manner. Smoke is drawn in through one tube and is forced out through another The Dumb Turk. He Smokes Cigar- ettes and Doesn’t Know It DUMMY who smokes cigarettes as realistically as a living human being is now used to advertise the fragrant aromas of different grades of tobacco. The idea is not to show the public how well a cigarette burns or how well the dummy smokes it, but to enable smokers to smell the smoke as it is automatically puffed out by the ap- paratus concealed within the dummy. The moment cigarette smoke is drawn into the mouth it loses its odor. With the dummy none of the frag- rance is lost. There are two tubes within the dummy. One leads to the cigarette in the dum- my’s mouth and _ thence to a bulb. A second tube extends from the bulb to the mouth. The smoke is drawn in through the first tube and through a valve into the bulb. When the bulb is pressed the smoke is forced into the second tube and led to the mouth, where it is expelled. A small mo- tor operates the bulb. It is regulated so that the dummy can smoke fast or slow as the exhibitor desires. Rubber bulb The annular rubber pad com- pressed between the base of the tire and the steel felloe band locks the tire in place Popular Science Monthly An Easily Adjusted Tire. It Locks Itself on the Wheel A NEW type of tire just brought out by an Akron manufacturer is designed to eliminate the trouble experienced in mount- ing either a demountable or pressed-on solid tire on the wheel of a motor-truck. It employs the compression of an annular rubber pad between the steel base of the tire and the steel felloe band on the wheel to lock the tire on the wheel. The annular ring-or pad of rubber is about one inch thick and is the same width as the tire proper. This rubber pad is inserted between the steel base of the tire and the steel felloe band on the wheel. The pad is retained by two steel rings, one on either side, bolts extending clear through the pad from one » ring to the other.. Twelve of these bolts are employed, each with a nut on the outside of the wheel. As these bolts are screwed down by means of a socket wrench, the width of the rubber pad is decreased while its thick- ness is increased. This swelling of the pad exerts pressure on both the base of the tire and on the steel felloe band, serving to lock them together and make them revolve as a unit. The tire is removed in a few seconds time by merely loosening up the twelve bolts and permit- ting the pad to assume its natural thick- ness. Then the tire is simply slid off the wheel. Aside from the characteristic of easy at- tachment and removal, the pad also serves as a cushion to the tire itself, tending to reduce the road vibration transmitted to the wheel, axle and driving mechanism. Other claimed advantages for the pad are that it permits greater truck speed without harmful effect, greater tire mileage and abil- ity to wear the tires down nearer the base, all because of the greater resilience of the wheel as a whole due to the increased amount of rubber between the axle and the point-of con- tact with the ground. In application, tires of the next larger size or two. inches greater in diameter are employed. In this way wheels of the same size as those on which the ordinary tires are pressed may be used. The pad also prevents the sur- faces from rusting together. Popular Science Monthly 269 Closing Up a Wound Without Using The ‘‘Pretty Maids’’ of a Chinese a Surgeon’s Needle Window Garden NEW method of drawing together “ ARY, Mary, quite contrary, how the parts of a wound so as to does your garden grow?” “With tinkle bells and conchal shells and pretty maids all in a row.” So goes the English nursery rhyme, but it remained for the Chinese to make a practical application of the idea. The two photographs below show how the pretty maids are made to grow in the minia- ture flower gardens of China. But any little American girl may do the same thing with the head and arms of an old discarded doll. First an ordinary flower pot is filled with soil. Into the center of this is thrust a stick about ten or twelve inches long. To this other sticks are tied (ar- give Nature a chance to knit them permanently’ together again, eliminates the sur- geon’s needle, together with the pain of the sewing-up process. In this new method a lacing plaster is used, a strip on each side of the wound. After the wound has been cleaned and dressed, ‘the plaster is ap- ‘plied, one strip on each side of the cut, with the edges of the plaster about one- quarter of an inch from the edges of the wound. Loops of thread, like a scalloped edging, are pro- vided in the plaster to receive the lacing, which ranged as shown at left - is stiffened and used with- in the illustration) in out a needle. The ends et ae ce ae ies order to give breadth to 5 awn. to- . of these scallops are ¢ether and held in place until healed the lady’s skirt when she woven into the material is dressed in her verdant so that they will not pull out. When the costume. The head of the doll should be thread has been looped through opposite fitted securely on these sticks, and the arms scallops in the sections of the plaster, the should be fastened with twine or wire. loops are drawn up, thus gently Plant in the soil a few seeds closing up the gap in the torn of dwarf nasturtium, morning flesh. The wound is left glory or any small creeper exposed to the air through and keep them well the threads, so that it watered. As the plants may be drained and ex- grow up, train the shoots amined occasionally with- on the framework of the out disturbing the ar- doll and pinch them off rangement of the plaster. as soon as they reach the If a dressing of gauze is neck in order to cause a used, it may be changed thicker growth at the when desired without re- sides. Soon the entire moving the plaster. The frame will be covered, threads are clipped and and the lady will be removed, leaving the wound gorgeously attired. But exposed for the treatment. in order to keep her Afterwards the plaster is looking her very best laced again with fresh continually, it will be thread. One application necessary to keep the of the plaster strips is = =p vines closely cropped. usually sufficient for the — Gandia aitabe ots Ornamentation is pro- entire period of healing. their verdant costumes vided by the blossoms. 7 Mollycoddling the Microbe Some of the deadliest germs are very deli- : cate and require plenty of milk and eggs ares of cultivating deadly germs, the typhoid bacillus, for instance, ]|@ with as much ee care and attention to diet and environment as would be given toa delicate orchid or even to a beautiful baby! That is what is being done at the American Museum of Natural History in New York city. Up in one of the tower rooms there is a regular nursery for germs. They live in tubes, rows on rows of them, in neatly ar- ranged and classified wooden racks. Each tube contains a jelly, and on top of this jelly is a wrinkled mass of whitish, yel- lowish or brownish scum. In this scum are the babies—or plants, as the Museum bacteriologist classifies them. The jelly is made up of meat, peptone, and the extract from agar, a Japanese sea- weed. Some of the germs, however, are ee TURE ui $ ROTE RIA SHOWING THEIR AGTION ON MILK MEAT AND SUGAR SOLUTION Needless to say, the germ-filled tubes are han- dled with extreme.caution by the examiners fastidious and require egg; others must have blood; still others need milk and special kinds of salts. The food preferences of each particular germ are as carefully studied and compounded as are the special dishes in the diet kitchen of a hospi- ~ tal. Some of the. bacteria will live for weeks without special attention, while others must be transferred toa fresh tube of food jelly every three days. To transfer them, the bacteri- ologist in charge simply touches the scum in the tube with a platinum needle. The bacteria adhere to the needle but readily drop off into the fresh jelly. The fact that 400,000,- ooo of the typhoid bacilli could be packed into a grain of granulated sugar will give some idea of the size of the microbes. OF BACTERIA STREAK : @ SHOWING COLOR AND APPEARgYCE OF GHOWTH OF ‘VARIOUS SPECIES Photo American Museum Natural History Olen Raa In the yellowish, whitish or brownish scum which is to be found in each of the tubes there are millions of infinitesimal microbes feasting and flourishing on the food jelly of their choice 270 : : . 4 : ' shelf is fastened to the windows with perfect safety, _ provided city ordinances al- Popular Science Monthly Put Your Flowers Outdoors on This Adjustable Window Shelf TH a new adjustable window-shelf invented by ‘Earle H. Bartlett, of Kansas City, Missouri, flower pots can be placed outside the ow it. - The shelf permits the window sash to be raised or lowered. Besides, it can be attached to ledges or stools of various sizes, a bracket support ip compensating for different i% widths and maintaining the shelf in the proper horizontal position. The window ledge by screws and a metal strip so that the window-sash can be raised without striking it. To support the front por- tion of the shelf there is a brace or bracket with a wing-bolt = LUA Four-cylinder jump spark wheel. Sketch M dp H sation ar if the motor shows a gear- HT coil should _ back-fire driven type. Magneto i if sae the end will slip L ylinder “make and é This. latter type soi oenm fob Fars Pe off the “handle; is undoubtedly eats "4 STA but never close the most practi- the thumb cal for use in an open boat or where the bilge water may be splashed on the flywheel; for either type K or L will slip more or less if the flywheel gets wet. All of these magnetos are equipped with a governor to prevent them from being driven too rapidly when the flywheel is revolving at excessive speed. High tension magnetos are always geared to the engine. Practically all gasoline motors, especially marine engines, can be readily started whether or not the operator is familiar with his special type of engine, if the fol- THREE-TERMINAL COIL MAKE AND BREAK Three wiring diagrams for a four-cylinder marine en- gine, one for the jump spark, with single and quad- ruple coils and the make and break type connections FOUR-TERMINAL COIL FOUR-TERMINAL COIL ap WIRING DIAGRAM “WITH MAGNETO around the han- dle, as.a broken. arm or shoulder may result. Rock the balance-wheel back and forth and give it a quick pull over center the way you wish the motor to go. The rocking operation draws the gasoline charge into the cylinder and if the proper charge is taken in, the motor will start. It is also good practice to prime the motor through the priming cock before attempting to start it, and a little oil mixed with the gasoline used for priming will be of great assistance. After the motor is under way, advance. FIVE-TERMINAL COIL SEPARATE COILS MAKE eo Bo | i : SEPARATE THREE- TERMINAL COIL SINGLE COIL op Wiring diagrams for connecting up a single cylinder as well as a double cylinder marine engine with batteries, spark coil and timer, also magneto and timer using. single and double coils Popular Science Monthly Ew. While there are many steering de- vices on the market these three shown are the most popular the timer until the motor speeds up, and then proceed to adjust the needle valve on the carbu- retor until the best results are obtained. A slight movement of the needle valve will make a great difference in the mixture being fed into the compression chamber. For that reason it is advisable to go slow and try the different points. Too lean a mixture will cause a back fire while too rich a mix- ture will cause the motor to slow down. motor, be careful that the mixture is not too rich. In the case of too rich a mixture close the needle valve until a blue flame is shown through the relief cock. motor backs fire on all carburetor adjust- ments the gasoline pipe or needle valve is clogged and does not allow the proper flow of gasoline. Never use a wrench or screwdriver on a motor unless you know exactly why If you get a back kick or a sprained wrist from your motor, it is your own fault. you are doing it. Mag. i Ty bial A | J Ld Single plank, with ordinary calk seam SG RET eS EE Single plank, hollow and round style of seam rd a Psi sentra a mere oat a pen B | F v Single plank,with lap seam _ Single plank,narrow slats strung on a wire fam ram i j Fy C ks 6 SARS &! Single plank, ribband carvel —_ Double plank construction construction ————_— I Ty abd 1 Dd | U H Single plank roughly put on Lap strake plank and covered with canvas construction Edge nailed construction J K Plank put on improperly, not hollowed to fit flat, on frame The planking of the hull covers the ribs and frame of the boat and it may be applied in ‘several ways Plank proper! hollawed an rounded to fit \curve of frame} When starting the be opened. If the Never try to MUTT Ul SIU) The three methods of connecting up a magneto for being driven from the fly- wheel of the engine a small amount fed from each, always bearing in mind that too much _lubrica- tion is almost as bad as too little, as it causes carbon to form in the cylinder. The fuel supply should now be turned on, both at the tank and at the carburetor. The needle valve on the carburetor should be opened slightly and the .carburetor primed, as_ before mentioned, to make sure of a good sup- ply of fuel. As soon as the engine starts, all oil cups should In case a four-cycle engine fails to start at once, turn the crank over under varying conditions of fuel and air sup- ply, after making sure that the igni- tion system is operating and that the fuel is flowing into the carburetor. start a motor with the spark advanced. The spark should be retarded before the engine crank is turned over. For throttling or slowing down, the expert uses the throt- tle; the amateur leaves his throttle open and retards the spark and thereby makes the motor back fire, thump and overheat. Oil and grease cups should be filled and The torpedo type of stern is a very popular style and is adapted for shallow waters 280 Taking Snap Shot Action Pictures at Night with a Flashlight Pistol O take flashlight photographs the usual Popular Science Monthly shops and offices of the railroad to facilitate the collection, and a baling machine has been installed by the company, which bales 1,500 tons of old papers annually. This procedure for the photographer is first to set up his camera and tripod, open the lens with one hand, and then fire the flash powder with the other. Because of all this prepara- tion, it has been im- possible for the photographer to take instantaneous or snap shot photo- graphs by flashlight. Now, with the aid of a novel flashlight pistol invented by a waste paper is sold for fifteen dollars per ton, so that about $22,500 is realized by the company in this way. In New York city, a social workers club is pay- ing one cent to the children of the poor, for every pound of old paper they bring to the club head- quarters. il IEEE An Elastic Cord California man, the By holding the tripod is dispensed with. The operation of the pistol is purely mechanical. The fact that the force of the powder explosion operates a lever which in turn manipulates the camera shutter, relieves the photographer of all responsi- bility. From the diagram it will be seen that the force of the explosion raises a steel lid which operates the control wire to the shutter. Hence the shutter is opened and closed at exactly the instant the flash is at its brightest. There is no possibility of an over or under-exposure. However the device permits the use of the various grada- tions of shutter timing. A spring-operated spark-wheel sets off the powder charge. right hand and the flash pistol in the left an instantaneous flashlight photo- graph is made. The Collection of Old Newspapers Has Become a Thriving COVER FORCED UP BY POWDER CHARGE camera in the POW FLASH LIGHT POWDER PAN for the Sash Curtain Papa THIS END x _extremely > I<—SHUTTER simple and in- i 4 expensive device for ~ holding sash cur- tains employs an elastic cord which is drawn through the curtain in the usual way, the ends being clamped down at the sides of the window as shown in the illustration. The elasticity of the cord makes it adjustable to any window. When it is necessary to remove the curtain for laundering or to wash the window, one end is unclamped and the curtain is slipped off the cord; then the cord is looped up out of the way on the other clamp. The cord is always taut and there is no possibility of sagging. SPARK PRO- DUCING ALLOY Business N account of the shortage of paper, old newspapers and other waste paper have risen to an im- portant place in the commercial world. Today the man who throws down his paper in the cars after he has finished reading it is regarded as somewhat of a spendthrift. On the Pennsylvania Railroad, for instance, waste papers are now carefully collected. Ten thousand bags have been distributed to stations, work- An elastic cord holds the curtain taut and is adjustable to any window 2 ‘Ss. Never-Slip Calks Used on Lawn-Mower Wheels HE wheels on a campus lawn-mower drawn by a horse became so smooth that it was impossible to cut long grass with it, because the wheels would slide. The trouble was overcome in a satis- factory manner by using the never-slip calks that are ap- plied to horseshoes. Twelve of the calks were put in the rim of each wheel. The- calks are small and will not tear up the turf, and they give plenty of tractive ef- fect for the ordinary cutter reel in long grass. Three Methods for Finding a Chosen Card OR this trick the chosen card must be worked to the top of the pack. If itis there already, well and good; but if not, it must be brought there by some means or other. This is generally an easy matter, even without sleight of hand, and can usually be effected under the pretense of looking through the pack. When the card is once at the top a false shuffle may be given, to throw the onlookers off the track. Then push the top card out sideways beyond the rest of the cards. Let the pack fall on the table. The resistance of the air will cause the top card to turn over and appear face upwards, all the other cards remaining face downwards. Another method is as follows: Get the chosen card to the top of the pack. Slightly moisten the first and second fingers of the right hand, and take hold of the pack with the fingers above, thumb below. Jerk the hand containing the pack smartly down- “ Horseshoe calks in rim of mower wheel FOR PRACTICAL WORKERS wards, at the same time relaxing the fingers, and it will be found that the entire pack falls to the floor, with the exception of the chosen card, which will stick to the moistened fingers. This will be the only card left and the card selected. The third method is very similar to the preceding. The chosen card is worked to the bottom of the pack. Mboisten the fingers slightly and take hold of the pack with the fingers below, thumb above. With the disengaged hand strike the pack - smartly and at the same moment slightly relax your hold on the pack. It will be found that the entire pack will fall to the floor with the exception of the bottom card which adheres to the fingers. Making a Push Cart Oil Sprinkler for Dusty Drives N mid-summer when the suburbanite is confronted with dusty driveways and walks, he will appreciate an acquaintance with the home-made oil sprinkler shown in An oil barrel swung between a pair of wheels and piped to make a sprinkler device the illustration. It consists of a steel frame mounted on wheels, that carries an ordinary oil barrel. Inserted in the bung of the barrel is a short piece of pipe 281 282 equipped with a shut-off. To this is attached the sprinkling pipe. This pipe should have perforations about. 114 ~in.- apart, of sufficient size to allow the oil to flow freely. The frame may be easily made by the average handy man, but where the materials are not available the local blacksmith will build it at a small cost.—J. C. GRINDELL. Tipping Truck for a Large Cylindrical Oil Tank ECAUSE the fau- Popular Science Monthly proofing can be done by applying a facing to the concrete surface before it begins to harden. A powder can be purchased for this purpose which is mixed with cement in various proportions up to 5 lb. to a bag of cement. This mixture is applied to the con- * crete surface and finished smooth with a plastering trowel—giving a fine, moisture proof wall or floor. End Mills Made of Broken and Worn Twisted Drills | RILLS which have cet of a kerosene oil barrel leaked more or less continually, the owner devised the tip- ping truck illustrated. The tank was fitted with wheels from a discarded farm spring wagon. Two cross-pieces were run under the tank, the ends being supported on cleats fastened to the spokes on each side of been discarded be- cause they have become too short through fre- quent grindings or broken off in use, still have considerable value as end mills when placed in a milling machine for cutting keyways, ete. They may be held in an ordinary three-jawed chuck, or a holder may be made up with a taper the tank. Two planks were laid and cleats nailed to their The oil tank stands in an upright position on the wheels at the rear of the track shank to fit the spindle of the machine, and a number of split upper surfaces to serve as a track for the wheels. Bumper pieces were placed at the right dis- tances on the ends of the tracks tostop the wheels from rolling far- ther than neces- sary to tip the tank horizon- bushings pro- vided, one for each size of drill to be used. A setscrew will securely clamp and hold the drill in position in the bushings. They should be ground square, for what is commonly tally. With this arrangement it is not necessary to have a faucet at all as a short piece of pipe is sufficient to guide the flowing oil into the retainer of a lamp or other receptacle. Waterproofing for Concrete Walls and Floors HE general impression is that concrete is water and moisture proof, but such is not the case for if the surface were flat or concave it can be made to absorb almost any amount of water that is put upon it. For certain uses, it is very important to have a waterproof concrete and the water- When it is required to fill a lamp or remove some of the oil the wheels are rolled forward tipping the tank called betta: ing, on the end : and the clear- ance for steel should be about four degrees. On account of the shortness of a broken twist drill, its body will be as rigid for the work as the end mill, and owing to the construction of the shank it will stand considerable rough usage. If fairly deep cuts are to be made, each land should have a little additional clearance stoned on it right up to the edge of the flute. Considerable money can be saved in this way and the results will be almost as good as those obtained by the more ex- pensive end mills——A. DANE. Popular Science’ Monthly 283 Race meets at stated periods stimulate the manufacture of small cars in various shapes’ and forms, but generally the construction of some favorite large car is copied in miniature Miniature Automobiles and Their Race Meets INIATURE but practical motor-cars are being built by~ youngsters in California in great numbers, and of widely differing designs, and the sight of them whizzing through the streets of Los Angeles is so common that they no longer attract special attention. The rapid development of junior car building in that section is largely due to the stimulating influence of frequent road races in California, planned especially for juniors. A racing association for boys has been formed in Los Angeles and a number of meets have been held, with cups and cash prizes awarded by motor enthusiasts. The little automobiles are largely home- made, with the exception of the engines and some of the more complicated parts. Asa rule the engine from some outworn motor- cycle is bought for a few dollars and adapted for use in a diminutive car. The steering wheel is usually secured. from an auto-wrecking establishment, and_ the wheels may be from bicycles, motorcycles or coasters; though one or two small machines make use of the pneumatic-tired wheels designed for airplane use. The chassis, body, transmission, steering device and gas tank are as a rule of home manufacture. It will be seen that to build a neat and efficient miniature car requires considerable ability as a woodworker, machinist and tinsmith. Of course the manual training received in the public schools is very helpful in developing mechanical skill. The photographs show.a number of home-made models and one factory-built junior car. Hanging Backing Cloth for Wall Paper N hanging cheesecloth or muslin for back- ing on which to hang wall paper, wrinkles will be prevented if you first wet the cloth with clear water and when dry size it with alum water, 1 lb. to the pail. 284 Simple Oscillograph to Record Current Alternations LTERNATING electric current de- rives its name from the fact that the current reverses the direction of its flow. It first flows in the wire in one direction and then dies out to zero and then flows in the opposite direction and dies out to zero or no current again. This constitutes what is The coil mounting and the coil, and the manner of mount- ing a tin can on a disk phonograph to carry the film known as a cycle. Alternating current of 60 cycles means that the above operation occurs sixty times every second. Alternat- ing current is graphically represented by what is known as a “‘sine curve’’ as shown. Just why this curve represents alternating current may be shown by a simple experi- ment as follows: Takea piece of paper and lay it flat on the table. With a pencil in one hand, draw a mark by vibrating it rapidly across one end of the paper, the pencil retracing its own mark back and forth. At the same time, with the other hand draw the paper from beneath the pencil point and in a direction perpendicular to the line you have been drawing. The result will be as illustrated on the follow- Popular Science Monthly light is reflected from a mirror which is being vibrated by the electric current. A Braun Tube oscillograph operates some- what differently, however, no mirror being used. The illustration shows a simply made oscillograph, and, while imperfect in its action, very interesting results may be had with it in studying alternating current and its rectification. A rectified alternating current is one in which the current pulsa- tions have been changed (by electric, mechanical or chemical means) so that the current flow is in one direction only, as in the familiar aluminum-cell electrolytic rectifier. The trouble in making an oscillograph is to get away from our old friend (or enemy) “in- ertia,’’ which an eminent scien- tist once described as ‘‘the pig- headedness of matter.’”’ Matter in motion seems to want to keep on moving and matter at rest wants to stay at rest and it requires force to either start or stop it. The earth keeps on revolving because it is a large heavy mass and does not seem to meet with much resistance. If you have ever tried to push an automobile out of a garage you will remember that it was comparatively easy to keep it moving after you had once got it started. This is exactly the trouble in making the little mirror and moving parts of the oscillograph. They must. be made very small and light to get the best results so ing page and represents a sine curve although imperfectly. Had you been able to vibrate the pen- cil regularly and draw the paper along at a regular rate of speed, the result would have been a perfect sine curve. The above is exactly what an oscillograph does, excepting that a photographic film is substituted for the paper and a spot of light for the pencil point. The spot of The coil and magnet mounted on a base, and the delicate mechanism of the moving parts for casting the light ray that when the electric pulsation starts, the little mirror (influenced by it) starts, and when the current stops the mirror will stop. This is not possible to realize in practice but it may be approximated. With alternating current of 60 cycles there are 120 current pulsations per second and Popular Science Monthly it keeps the little mirror very busy trying to follow them. As shown, the shaft of the moving part consists of a small brass pin sharpened at both ends and with bearings made by > small dents (not holes) in the two pieces of thin sheet brass. A small piece of iron wire is fastened at right angles to the brass 285 of ‘the ‘bearings on the shaft is made - adjustable so that the mirror will not swing too far. This dampening effect is quite desirable in making oscillograms of rectified current, so that the mirror will not swing beyond the zero point. With I10 volt A.C. a lamp or other resistance should be placed in series with the coil of wire. If An oscillogram and a simple way of making the curve by drawing a piece of paper under a moving pencil to illustrate the process by which the recording: oscillations are made by the machine pin with. a drop of glue or sealing wax. A mirror (somewhat larger than the head of a pin) is glued to the center of the iron wire. The mirror is best made from a microscope cover glass. This is a small square of very thin glass and may be dropped into.a test- tube of silvering solution for which there are various formulz. The test-tube should be of such. size that the glass will just fit intoit. This will support the glass upright in the tube so that it will be evenly silvered on both sides. The silver coating is after- wards removed from one side of the glass by touching it with the end of a tooth-pick a core is used, it should be made up of small iron wires. The size and amount of wire necessary on the spool or electromagnet is best found by experiment. The spool is fastened by rubber bands to the support, making. it easy to substitute various spools containing different sizes and lengths of wire. Very little current is required as the mirror is influenced by the electromagnet at considerable distance from it. The- mirror and moving part should be mounted a little nearer to one pole of the permanent magnet than the other, so that the spot of light is adjustable by moving the permanent indicated by a straight line in the first two, being photographed without a current in the coil moistened with nitric acid. After washing and drying, the mirror is broken into bits and a small piece selected as nearly round as possible. A piece of the silver chipped off the back of an old mirror might be used in place of a mirror. By means of the small screw, the tension magnet backwards or forwards as desired. As a source of light, sunlight is excellent for viewing the oscillograms directly. The sunlight is allowed to fall on the mirror and is then reflected on to a piece of white paper as a spot of light. When the mirror is being vibrated, the spot of reflected light 286 becomes a line, as in the experiment with’ the pencil and paper. By waving the paper screen back and forth rapidly in a direction perpendicular to the beam of light, the oscillograms may readily be seen. This effect is due to the persistence of vision. placed between the mirror and the paper screen tends to sharpen and brighten the image of the light spot. For photograph- ing the oscillograms, sunlight might be used by reflecting it through the keyhole on to the mirror in a dark room. On account of the movement of the sun, how- ever, the spot of light has an annoying way of moving off the mirror just as all adjust- ments for taking the photo have been made; therefore a small incandescent lamp is more satisfactory. The lamp used in this case was similar to those used for automobile headlights and was a 6-volt 16-candle power lamp with a small concentrated tungsten filament known as “focusing type,’ it being essential that the light should come from as small a point as possible. A storage-battery was used, which gave a somewhat higher voltage than that of the lamp. This gives a light of greater actinic power although not conducive to long life of the lamp. The lamp was enclosed in a light-tight box painted black on the inside and having a small hole through which a beam of light might fall direct from the filament on to the mirror. A photographic plate may be drawn by hand rapidly across the beam of reflected light and the image obtained thus, although the results would be imperfect owing to the difficulty of moving the plate rapidly, evenly and uniformly. The uneven oscillo- grams shown were taken on a plate moved by hand. A disk phonograph was hit upon as being a device which revolves smoothly and at a regular speed. A hole was punched in the exact center of a coffee can, and fitted over the little knob in place of a record. The can was covered with black paper to prevent reflections. spot of light on to the can, a piece of photo- graphic film was fastened around the can with rubber bands, a piece of cardboard between the mirror and film acting as a shutter. The phonograph was given a chance to get up speed and the shutter was opened and closed again when the phono- graph had gone around once. One revolu- tion is best gauged by fastening to the A small hand magnifying glass. After focusing the Popular Science Monthly revolving table a piece of wire or cardboard so that it will brush past a finger held near it, when the piece of film has just passed the beam of light. When the wire touches the - finger, it is a signal to open the shutter and the next touch is a signal to immediately. close it. : a Oscillograms are shown of an alternating current of 60 cycles before and after rectification. The zero line is photo- graphed by allowing the phonograph and film to revolve once while the spot of light is at rest. This may be done before or after making the oscillogram. The oscillo- gram shows the rectification caused by a one-cell aluminum rectifier consisting of a lead plate and the tip end of an aluminum wire dipping into a solution of sodium phosphate. A Home-Made Steam Volcano to — Explain Volcanic Activity ELIEVING that steam causes the ac- tivity of volcanoes, a Frenchman has used that agent inimitating Natureina most realistic way, as illustrated and described in La Nature. The whole experimental volcano is made ina shallow basin about 2 ft. square, in which a wet mixture of ys ia 7 Wid b: Gj Ww thy a Y D yy, a Po 2 ar ar a) ; — eae —| [Util Be = WA = ~ = =. = > A sectional view of miniature earth works showing what takes place in volcanic action sand and clay is placed so that the lower side represents the sea and the upper side the land. The basin is placed in an in- clined position, the higher part holding the land and the lower part the water. The metal basin provides a way to heat the bottom so that an even mean temperature is obtained on the surface. When the flame of a gas jet is applied, as shown, Popular Science Monthly it takes only about 10 minutes for the volcanic phenomena to begin to appear. In Nature layers of hard rock or similar obstruction may deflect the rising fumes, The miniature volcano in action as it ap- pears from the lake end of the box and this may be imitated by placing a sheet of slate in the sand, as the dark line shows, a short distance from the bottom of the basin. With this plate in the sand several vol- canoes may be produced in line with its upper edge. By this arrangement the vol- canic action will appear at some distance from the source of heat. This illustrates how linear groups of volcanoes are formed in Nature. By varying the positions and the number of plates the volcanic action may be concentrated near the top. A Solution for Reclaiming Over- Exposed Blue Prints HEN washing blue prints, if to drops of peroxide are added to each gallon of water a solution will be made that will produce even blue prints. The blue print is washed as usual in clear running water, after which it is placed in the peroxide solution and is finally washed m clear water to remove all traces of the salt. A blue print of correct exposure or one under exposed will not be affected by it, but in over ex- posure the chemical will restore it to the true color. Where old blue prints have be- come faded this solution will restore them. 287 A Double-Deck Revolving Clothes Hanger for a Yard HERE backyard space was at a premium, the double-deck clothes- line apparatus, shown in the illustration, was made to serve the purpose of drying as satisfactorily as the ordinary line that takes up so much room. The double-deck ar- rangement is built on a center upright made of 25 ft. of 2-in. galvanized pipe purchased from a local plumber. The arms consist of 10 sections of I-in. pipe about 6 ft. long, threaded on both ends to fit into caps and bands that slip over the center pipe. The bands are movable, being held in place by a shoulder. Wires are strung around from end to end of each extension and each arm is supported by a wire. Two of these are placed on the center post, one for the ground level and the other for the second floor porch. The height for each hanger is adjustable. The lower hanger can be made just as high as it is desired by the person using it. The top circle can be arranged to reach the rear window or porch. The main pole is embedded in 3 ft. of concrete, affording a rigid foundation. The apparatus covers a circular space of the back yard about 12 ft. Meet nile Nap Ss Two sets of clothes hangers on a single pole serving a two-apartment house in diameter and has more than 150 ft. of hanging spacé.—CHARLES M. STEWART. 288 . To Prevent a Colt from Becoming Tangled in a Halter Rope N the illustration a device is shown that will prevent a colt from becoming tangled in the tie-rope of the halter. The & z I El E a = e as —4 a EB’ c @ The weight keeps the tie-rope taut all the time and the spring cushions the jerks old method of a weight is used, but a spring is applied to cushion the jerk a colt will give when first tied with a halter. The weight consists of a piece of hardwood 4% in. long and 3% in. in diameter. A 2-in. hole is bored in one end of the wood 4 in. deep, and a 1-in. hole bored through the center of the remaining 1% in. of the wood. This makes a seat for the coil- spring A to B. The spring should be 8 in. long, of the open variety and made of wire about 3/16 in. in diameter. ‘The tie- rope is passed through the spring. and secured by a knot at the bottom of the block as shown. The hole in the manger should be about 114 in. in diameter to take the tie-rope loosely. This will effec- tually prevent the spring: from passing through.—J. O. McDOoNNELL. Effects of Oil and Grease on Rubber Tires T is pretty generally known that gasoline, grease, oil and other fatty substances are solvents of rubber. If garage floors are not kept clean and tires stand in a pool of oil,-the treads soften and the traction strains in service stretch the rubber in a wavy outline, eventually causing it to separate from the fabric body underneath. Popular Science Monthly Probably the most damage is experienced from grease, in the differential housing, working out into the brake drums and then on to the side walls of the tires. This may result from loose bearings, too much grease or from using grease not suitable for differential. Grease and oil may be very easily removed by using a rag saturated in gasoline. Gasoline, although a solvent, evaporates quickly, and, if applied in small quantities, will not cause any injury when used as a cleaning agent. Ordinary injuries to the rubber cover do not prevent successful repairs but not often can work be well done when materials have been affected by oil or grease. Invariably blistering during vulcanization results. An Irish Thrush Rings for His Food OR a token of remembrance of a trip abroad a lady promised a friend that she would bring back a bird of some kind. . An Irish thrush was selected. When caged the bird cultivated the habit of pounding the metal bottom of his inclosure with a small gong top, taking hold of the edge with his bill and manipulating it just as a THRUSH RINGS BELLS TO fie. ATTRACT ATTENTION WHEN FOOD CUP IS EMPTY SMALL GONG | USED FOR AMUSEMENT XERCI Calling for food by ringing a string of sleigh- - bells which have been hung from the cage top workman does a pick. When his mistress fails to keep his food cup filled he jingles a string of sleigh-bells that are fastened to the cage top. Popular Science Monthly Iceless Refrigerator Using Evaporation for Cooling : it is not always convenient or possible to have ice for refrigeration. When such is the case, as in a camp or isolated places, the evaporation method may be applied. Milk or butter will keep much better by this method than in. the regular ice-box or refrigerator. A very satisfactory iceless refrigerator may be easily constructed as shown in the illustration. The measure- ments given are not arbitrary, as any size suitable for needs may be used, the entire cooling process being the result of the evaporation of the water as it flows down the burlap curtain forming the sides of the cabinet. A suitable cabinet for ordinary purposes is about 18 in. wide, 36 in. long and 40 in. high. It consists of a skeleton framework _of corner posts 2 in. square with a base and top band made of a board 1 in. thick and 6 in. wide. The side to be used for the front is fitted with two doors built up just as frames and hinged to the corner posts, meeting at the center just like cupboard doors. All of these openings are filled with burlap set in so that the outside surfaces will be flush with the outside sur- faces of the corner posts. This may be done by building a light frame of quarter- round or light stock just to fit in the panel. Stretch the burlap over the panels and ush them into the panel opening from the inside of the box frame. When this part is complete it makes a burlap inclosure without top or bottom. The bottom or support is made of a frame the same size as the main box with corner posts about I0 in. long and the band the same as for the top and bottom of the box frame. Within this box frame build an inverted pyramid of galvanized sheet metal, allowing the edge to come up and over the edge of the side rail on the base; then extend it up about % in. In the center of the pyramid solder in a metal tube foradrain. The upper projection of metal will catch any overflow of water and lead it to the center drain pipes. The top consists of a galvanized pan or tray the same size as the box frame and about 4 in. high, with a ventilator pipe soldered in the center. This pan is placed on top of the box frame. Wicks 4 in. in width are hung over the edge so that they will come in contact with the burlap sides. These wicks will evenly and slowly siphon the water placed in the tray to the burlap 289 sides. A little experimenting’ will be required to get the size of the wicks right for the proper flow of water. These can be made of lamp-wick web or felt. The size may require altering according to the weather, as some days will be more humid than others. The refrigerator is made in three pieces, the center part having sides of burlap Before placing the box frame on the base, small blocks of wood or the ordinary furniture domes should be used. under each corner post so that a space will be provided for the proper draining of the water. Shelves may be placed inside to rest upon brackets fastened to the corner posts. The edges of these shelves should not touch the burlap in any place. As such a refrigerator depends on the evaporation of water in air currents the box should be placed where there is a slight draft to produce the right circulation. The- air passing up through the center tends to draw the damp air from the sides. 290 ment houses in large cities are often Popular Science Monthly An Open Shelter for the Yard or Flat Roof of a Building HE flat roofs of tenement and apart- used as breathing places by the tenants. Shelters can be built upon them at small cost as_ protection from sun and rain. Our illustration shows one of these shacks, which is the result of the cam- paign for the preven- tion of tuberculosis by the New York State Department of Health. In the construc- tion, 2 by 4-in. tim- bers are used for the frame, and sid- Sterilization Is the Essential Factor in Canning Vegetables HE great secret of canning or preserv- ing lies in complete sterilization. The air we breathe, the water we drink, all be 7S Re The flat rap space on Ai buildings in all cities provides an excellent place for the shelter fruits and vegetables, are teeming with mi- nute forms of life which we call bac- teria, or molds, or germs. These germs are practically the sole cause of decom- position or rotting. The exclusion of air from canned articles, which was formerly supposed to be so important, is unnec- essary provided the air is sterile or free from germs. ing boards for the back and sides. The front 7 of the shack should face slightly to the east of south and be left open, but it should be pro- vided with a 1 SY canvas curtain, tacked on a= SSeS i L] I PLAN LiL LL) CoC) im my <= Pu I =e PK = Loe 3° —— SECTION AA roller so that it | may be closed in stormy weather. The most economi- cal materialsare rough boards for the frame HET UL Tr ” a“ + 2X8 FRONT ELEVATION SECTION B-B The exclusion of air is neces- sary only be- cause in exclud- ing it we ex- clude the germ. In other words, air which has been | sterilized or freed from germs by heat or mechanical means can be passed continu- ously over canned articles without affect- ing them. Germs which cause decay may be divided and tar paper or something similar for roof- ing. The material list is as follows: 4 sills, 12 ft. long by 2 by 4 in. 5 floor joists, 12 ft. long by 2 by 4 in. 14 studs, 14 ft. long by 2 by 3 in. 5 plates, 12 ft. long by 2 by 3 in. 1 front plate, 12 ft. by 2 by 6 in. 1 rail for sliding sash, 12 ft. long by 2 by 8 in. 9 rafters, 14 ft. long by 2 by 4 in. 300 ft. of novelty siding. 250 ft. of shiplap roof boards. 4% roll of roofing material. 10 pieces of I-in. round for roofing. I canvas curtain on roll. 4 sliding sash; 1 casement sash and frame. Strips of sliding sash, hardware and paint. Plans for the construction of an open air shelter shack for a yard or open air sleeping quarters on a flat roof into three classes —yeasts, molds, and bacteria. Yeasts are easily killed, so they can be left out of consideration in canning vegetables. As a general rule, molds are likely to attack jellies and preserves. The spoiling of vege- tables is due primarily to bacteria. Bacteria are also much more resistant to heat than yeasts. They thrive in products like milk and in meats and vegetables rich in protein, such as peas, beans, etc. Keeping these products at boiling temperature for about 1 hour, upon two or three successive days will kill all bacteria, even the seed forms, which are difficult to destroy. Popular Science Monthly A Self-Acting Fountain for the Home Conservatory HE making of any contrivance which _ when started works automatically and continually on its own power, is always a satisfaction to those mechanically inclined, 291 shown by the arrows. The right pipe pas- ses through and down to within 1 in. of the bottom of the lower tank: All of these pipes are fastened to the bottom of the top tank before the two tanks are connected, after which the cover of the top tank is soldered at the joints. The center and the right pipe should project through the cover of the tank a dis- tance equal to the thickness of the basin-shell, and these two pipes should also be threaded on the inside, the center one to receive the nozzle of the basin, and the other the plug for starting the fountain. The action of the fountain is as follows: Fill the fish-basin with water, then screw off the upper part of the nozzle and allow the water to run into the top A garden fountain worked by pressure, derived from a weighted piston on water in a near-by cylinder (note dotted lines) — and I do not doubt that a fountain and fish pond which I made will be of interest to others. The basin or pond may be of any depth or diameter. The one shown was a large pan taken from the foot of a glass floral stand, which had a projecting neck in the center. This was removed to make room for the center pipe of the fountain. With the aid of my lathe I turned a piece . of brass tube about 11% in. in diameter to true its end, and with this, using sand and water as an abrasive and keeping the lathe in motion while holding the pan against the tube with some pressure, the neck was easily cut off leaving a hole in the center the diameter of the tube. Another’ hole was bored in the same way for the down pipe into the lower tank. The location of this hole was at one side of the center. It may be possible to obtain a basin where it can be bored ready for use. The stand for the fountain was built of two tanks made of zinc, the bottom one being set in a molded base. This tank is finished on the top with a flange all around and has a small faucet in the side near the bottom. The top tank, which is slightly less in depth than the lower one, is shown fitted to a 3%4-in. molded board and has three upright pipes fitted in the positions shown. The left pipe passes through the board and the center one is fastened to the bottom with an inlet at each side, as tank until it is filled to within % in. of the top. Replace the top part of the nozzle and remove the screw-plug: The water will rush down the pipe on the right side and compress the air in the lower tank, which forces the air up through the pipe into the upper tank, thus compressing and . AM t | | tn Mi ‘ it | — rod = ARAM Aly Tt 1 AIR PASSAGE AIR CHAMBER |E forcing the water up through the nozzle into the air. If the fountain is a very small one it need not be fitted with a screw-plug or a faucet. 292 In such case it is only necessary to fill the lower tank through the pipe having the screw-plug; then by turning the fountain up-side-down the water will run into the other tank. Place the fountain in its proper position and half fill the basin with water, which will rush down the pipe and set the fountain into action. It is not advisable to keep fish in the basin. A simple garden fountain is shown in the illustration. The pressure tank of this fountain consists of a vertical cylinder about 10 in. high and 6 in. in diameter with a piston heavily weighted. A pipe is connected with a fountain basin having a. center nozzle. To start this fountain re- move the piston and fill the cylinder with water. Replace the piston and the com- pressed water will force the fountain to act automatically.—JouNn Y. DUNLOP. ‘Unique Shelter of Palm Leaf Fans for Garden Entrance _N owner of a country place desiring to have something different from his neighbors made a garden entrance or shelter along the usual lines, but instead of cover- RAFTER &RIDGE BOARD sas ets i | jesse m ces i—s 3 ims = ms FY Details of the rafter framing and the man- ner of constructing a latticed ceiling frame MORTISS WW POG? ing it with shingles, prepared roofing or the like, palm leaf fans were nailed on as if they were shingles. These were placed in horizontal rows parallel with the rafters. To construct such a shelter the following materials are required: 2 posts, 11 ft. long and about 6 or 8 in. in diameter- 7 pes. of 12-ft. stock 2 by 4 in. in size. 35 ft. of sheathing. A quantity of palm leaf fans. The amount neces- sary depends on the size of the fans. The two posts are set about 3 ft. in the ground and tamped in solidly after the Popular Science Monthly upper ends have been cut sloping to fit the pitch of the roof. Two struts or joists are run through mortises cut in the posts 1 ft. 3 in. from their upper ends, or about 6 ft. 9 in. from the ground level. It is best to make this measure-- ment from the upper ends so that the proper measurement will be secured. The other joists are fast- ened on the same level with pieces across their upper edges for a temporary support until the rafters are in place. The sheathing is firmly fastened with nails. The rafters are cut on what is called the half pitch roof, because the height at the center is half the distance of the width. At the top a ridge board is set in between the rafter ends. This board is fastened in place as the rafters are nailed. The amount of sheathing given in the list is sufficient to allow a space between boards. This mode of construction can be used where a panel is to be set in on the underside of the joist. In case the panel is not used it is best to put on the sheathing without spaces, and with surfaces planed down to produce a finished effect. In the latter instance it will require more boards or about 45 sq. ft. The panel shown in the illustration is another feature of this shelter. It is made of thin material such as is used in the ordinary market basket, and is woven to- gether in basket fashion or like a chair bottom of the old hickory kind. It is then cut into a rectangle as shown and fastened to the upper surfaces of panel boards, when the whole is fastened in place on the under- side of the joist with finishing nails. After applying the palm fans in the same manner as shingles their upper courses on each side of the roof are finished with pre- pared roofing or ridge boards at the top. This gives a finished effect and covers up a large space that cannot be filled with the fans. The effect of the finished shelter is very artistic. = The finished shelter with its artistic roof of palm. leaf fans Leveling a Motion Picture Camera Tripod HE leveling of a motion picture camera tripod, especially if the panoramic head is used, is very essential. For this, Popular Science Monthly such cameras are generally equipped with two small spirit levels placed at right angles to one another. These are neither ac- curate nor easily read. At best the adjust- ment of two right angle levels on top of -three legs is a slow process. The civil engineers recognize this difficulty and make their surveying instruments adjustable to ‘the level positive by means of four screws instead of three. One of the camera men has attached to his tripod-head a very simple leveling device that anyone can adjust without loss of time. It consists of a brass tube rigidly attached to the under side of the tri- pod-head. The brass tube is about 1% in. in diameter and 8 in. long and has cut in its lower extremity some win- dow-like apertures through which the operator can observe the position of the plumb-bob hanging from the center of the upper end of the tube. The ease and rapidity of adjustment of ttm) the camera to level position Tube enclosing by observation of the plumb the plumb-bob is self-evident. — To those who care to put such a device on their cameras the following suggestions and illustration may be help- ful. The openings at the lower end of the tube should be large enough to permit the operator to see the plumb-bob easily and determine whether or not it is hanging in the center line or axis of the tube. The plumb-bob may be a straight piece of wire hanging freely from a ring support, which must be placed in the exact center of the upper end of the tube; but even if a small plumb-bob terminal is used for the sake of appearance, the support should be a wire so that it will not be likely to foul as would a string or chain if the apparatus should be inverted.—T. B. LamBerr. A Substitute for a Shoe Horn in an Emergency NCE when I had been in swimming I found myself without a shoe horn, but a friend showed me a little trick that supplied my need. Simply fold your hand- kerchief two or three times and lay it in the shoe at the heel, holding one end of it. As you press your heel down into the shoe 293 gradually draw on the end of the hand- kerchief, and when the heel is nearly all the way down draw out the improvised — horn. The shoe will slip on the foot easily.—A. A. KELLY. Preserving Surfaces from Which the Paint Has Worn Off HERE are sometimes places on the exterior of a house where the paint gets worn off and which cannot be re- touched without making a “‘botch job”’ of it owing to the difficulty of mixing the new paint to match the adjoining color which has faded. To preserve the wood in such spots until the house can be repainted, apply two coats of linseed oil with a rag. -This will improve the appearance also. Repairing a Worn Plunger in an Automobile Oil-Pump REQUENTLY the cause of an engine heating up rapidly can be traced to a faulty oil-pump. This trouble was en- countered in one of the cars in our garage and upon examination it was found that prone cap the oil-pump FORPLUNGER plunger was es badly worn. 3 This prevented ‘ ) it from deliver- TT ing the maximum amount of oil to the various q bearings. The drawings clearly illustrate the cause of the trouble. The constant rubbing of the hardened cam against the some- what softer pump-plunger caused the plunger to wear rapidly. This wear de- creased the stroke of the plunger. The repair was effected by providing a bronze cap to the plunger; first to bring the stroke of the pump back to its original dimensions and secondly to provide adjust- ment against wear. A shoulder was turned at the top part and a small thread cut on it. The cap was made from a cylindrical bar of bronze and was bored out and threaded on the inside. to fit the threaded portion on the plunger.—ApoLrH KLINE. Pg cx: Ga samen 9 it GUIDE FO PLUNGER Cap to lengthen worn oil-pump plunger 294 A Turned Down or Pistol Grip Handle for a Garden Rake HE straight handle on a rake makes it difficult to grasp when drawing it over the ground, especially where the heap of rubbish to be moved is large and long. To make a better hold for the hand I attached the turned down handle or grip 4 asshownin ~G the illustra- tion. A nano 8™P A curved grip attached to makes a the end of a rake handle broken handle on a garden tool as good as new. To apply the grip, cut a shoulder about 3 in. from the end so that the tenon will fit into a hole bored in the prepared grip. The grip is made of a block of hard, even- grained wood, cut to the shape shown. A long wood .screw passing through the grip and into the rake handle will make it rigid — FRANK L. MATTER. A Tool for Accurately Lining Shop Shafting N many shops where machines are belted from lines of shafting little attention is given to the alinement after the shafting has once been lined up unless the settling of the building, the weight of the pulleys and the tension of the belts make it so badly out of line that attention is called to it by the thumping and heating. Often shafting is so little out of line that it will show no sign of its condition although it will turn so hard that it will require much more power than it should to turn it. The usual test of throwing off all belts and trying the shaft by hand is not always reliable as the strain of the belts may change the alinement, and a section of shafting not perfectly straight may not show by that test, but may cause trouble when run at speed. The method described is a _ certain, practical and economical way of lining new shafting or of testing an old line of doubtful alinement. It can be applied in small spaces between belts and pulleys and will give dependable results of both the vertical and lateral alinement at one setting of the fingers. It is a great advantage to test a line of shafting while it is under the condi- tions of the tension imposed by its belts and pulleys, as a very tight belt midway Popular Science Monthly between two hangers may spring a section of the shafting. This will cause trouble which may not be detected by any test made with the belt off the pulley. The method is based upon the fact that when the center lines of two cylinders form a perfectly straight line in their relation to each other, two points, one upon the surface of each of the cylinders, will be exactly the same distance apart when the cylinders are turned. ; The fingers fastened as closely as prac- ticable to the ends of adjoining sections of shafting enlarge the diameters of the shafting and make possible the application of this principle with sufficient accuracy to prove whether the two sections of shaft in question are in perfect alinement. It is evident that the longer the fingers the greater will be the degree of accuracy possible to attain, though in many cases fingers which will permit the shaft to turn completely around will give sufficiently accurate results, as the shaft can be tested both above and below and on each side. The fingers may be made roughly, for it is immaterial whether they are perfectly square with the shaft or not, as their relation will be the same if each is firmly fastened upon the shafting. They may be held in place by a clamp or by a bolt as 7 wwe ee, H Seip cities ciatai- <= 3 SESS ahaa Ae SSSA se =e i. See J a) Wood arms attached to the ends .of both shafts to determine the accuracy of the lining indicated by the sketch. Care is necessary in measuring the distance between the fingers in their different positions, and in adjusting the shafting so the distance will be exactly the same in whatever position the measurement is taken. In lining a new shaft by this method several pairs of fingers may be used at once to save changing, in which case the middle section should be correctly lined and the rest of the shafting lined both ways from it—CHARLES A. KING. Popular Science Monthly through both for a king pin. - A Tractor Trailer Made from an Old Automobile _N old automobile having good mechan- . ical parts, but too out of date in appearance to be used as a pleasure car, may be utilized as a truck by attaching a trailer. The illustrations and description are for changing over and attaching a trailer to a 35 hp. automobile having a 4-cylinder engine with a three-speed for- 295 This is clearly shown in the detail drawing. An entire rear axle for an automobile with springs and tires was procured. All brake connections were removed and the number of spring leaves increased. These were refastened to the axle in their original position’ with longer spring clips. Four pieces each were made of A, B and C, of the dimensions given, from 3-in. steeh. These pieces made the spring suspension je 4" re , Stake body ESS eee | ee See E. Box body f King bolt 4 5X 10" X ‘: I fe Ae : Bre "s AD : ; F aa From 4 Side - sectional elevation q ¥é plate riveted to Koy Bent here chassis \2" wide i i i Vexeriron “iy, S = 4 Sheet ae Fs We oe at u metal = cover ‘ e | Beis ee - Longitudinal section of frame i Se Cast iron Detail of king pin and filler its bearing Details of the fifth wheel to attach to the rear part of a pleasure car frame, after the body has been removed, to make a trailer truck. Details are also given for its frame and body construction ward and a reverse. The wheel base of the one used was about 128 in. The original body on the automobile was of the touring type. To make use of as much of the body as possible it was-cut in two just back of the front seat and the rear part removed to make free use of the frame ' for the fifth wheel of the trailer. Two pieces of channel iron were then cut and riveted in the frame directly over the rear axle. These pieces support a _plate on which the bottom part of the fifth wheel rests, a hole being. drilled bracket A, the rear suspension brackets B and the spring shackles C. These pieces were cut from scrap at a structural shop and 34-in. holes were punched for rivets and 5%-in. holes drilled for the spring pins D. In fastening the pieces A and B to the frame it is much better to make a card- board or paper pattern and carefully center- punch and drill the holes. Securely bolt the pieces, using a cast iron filler as shown in the detail. The filler may be of any suitable piece of scrap iron that will fit into the channel. The projecting ends of 296 the bolt ends from the nuts was riveted over. Ordinary rivets can be used in place of the bolts, if they are put i: hot. The trailer frame was made of 3 by 1 13/16-in. channel iron with cross-pieces riveted in place, corner braces at each end and corner plates. The plate £ is 12 in. wide and %% in. thick, and as long as the trailer chassis is wide. riveted to the frame and cross-member F. The plate G is 12 in. wide, cut to shape from 3%-in. stock. Two circular plates H, 234 in. in diameter, were cut out and fastened in the center of each upper (G) and lower (£) plates. A 2-in. hole was then drilled through the center of both circular plates and the plates G and E for the king pin or bolt J, which was made of 1 31/32-in. stock with a 114 by 3-in. head, and a steel washer 3144 by \%-in. under the head. This bolt is 10 in. long ‘with a 4-in. length of threads. A spiral spring J was placed on the end of the bolt under the washer where it was secured under light tension with a nut, locknut and cotter. A groove was cut in each of the plates H for a grease retainer. Two holes were drilled in the plate G for two %-in. bolts to serve as bumpers for any side thrust that might be made. The floor of the trailer was placed on five pieces L cut from 2 by 8-in. oak. These were fastened with long bolts M, as shown. The opening left in the front part of the housing for the differential was covered with a plate bolted in place. The detail WN is for irons to hold the stakes, O is for the king bolt and P for the bracket connections. Inflation and Weight Governs the Resiliency of Tires ESILIENCY of the tires is primarily governed by the construction and quality, but is largely influenced by the inflation and weight carried. Naturally a 4-in. tire inflated to 70 lb. air pressure and carrying 800 lb. weight will ride easier than the same size tire with the same infla- tion, and carrying 700 Ib. weight. The heavier weight causes more deflection of the tires on the ground and increases the action of the side walls, thereby adding to the comfort of the ride. Increasing the deflection or flattening of tires, either by extra weight or reducing the air pressure, causes more of the vibration to be absorbed by the tires than by the springs of the car. It is securely | Popular Science Monthly A Cement Wash to Be Applied toa Damp Wall | GOOD cement wash for a damp wall may be made with 7 parts of soft, clear water, I pint of lime water and 2 oz. of table salt. Stir the cement enough to form a paint, adding any earth color desired, or use plain. Ls A Porch Swing Made from Your Favorite Rocking-Chair COMFORTABLE rocker can _ be converted into a swing without alter- ing or defacing the chair. The materials needed are two strips of wood about 14 by 1) in. and about 8 in. longer than the width of the chair seat; two sets of ham- mock chains; six stout screw-eyes and four — long, slim wood screws. The strips are fastened with screws to the under part of the seat frame. The chains are suspended from two screw-eyes set in a joist in the porch ceiling and are hooked into screw-eyes set near the ends of the two cross-pieces. Auxiliary frame under seat of a rocking- chair for fastening the ends of the chains When the swing season is over, these attachments may be easily removed and neither the chair nor the porch will be any the worse for the out-of-doors usage of - the chair.—T. H. LintHicum. © Sf GWM WU, Wp WE MG, LR SHIP has recently been devised which carries a veritable gale pent up, not in an oxskin, such as Homer’s Odysseus used to carry away the winds from the isle of A®olus, but in a cylindrical tank. This boat was designed primarily as a toy, a bicycle pump being used to fill the tank. With one pumping, 16-in. models have a cruising radius of about 100 yd. and run from % to 10 minutes, depending upon the rate of escapement of the air. In the course of experiments with air propulsion it was found that a simple jet of air, allowed to escape from a boat, is very ineffective. Placed in a semi-circular tunnel the jet be- DECK i MPRESSED~ i, Gig ill 4 Hy, yy V/y GL hae <5 ss Edward R. Smith bubble-way, Fig. 3, is soldered. With the air-pipe and nozzle, Fig. 4, in place, and with the tank tested airtight, the torpedo is ready for use. The speed depends en- tirely on the size of the jet aperture. This can best be regulated with a pair of pliers. Since speed is desired, it should be adjusted to exhaust the air supply in 20 to 30 seconds. How to Make a Submarine Chaser In the illustration, Fig. 5, there is shown one of the most interesting toys of today, the submarine chaser. Itisa V-bottom boat, all metal, war gray, with an automobile-type steering comes doubly effi- rd gear that really moves the rudder. cient. oe greater [J y It is 16 3 over all, saving of power is % YY with a 414-in. beam, made by leading the Yj fos is and runs from 5 to spent bubbles up in 2 Mil WGC OS s- 12 minutes at a fair an incline at the Lee pap speed. Any boy who stern to the surface, — =< e has a soldering set as shown in Fig. 1. Thus the lifting power of the bubbles NOZZLE Fig. 1. The compressed air is allowed to and tinsnips can build it at small expense. The hull with the is used in propelling escape in a semi-circular tunnel at the stern _the boat, or it might be said that the boat is continually coasting down a row of bubble rollers. Making an Air Torpedo Perhaps the most simple form of an air boat, as a toy or for experimental work, is the torpedo, in which an air chamber forms a greater part of the boat-body. This air chamber, as shown in Fig. 2, is a 2-in. cylinder with semi-spherical ends, into one of which a bicycle tire air-valve is fitted. To this end a stern piece, containing a extension of the stern-plate is cut from a single piece of sheet tin, Fig. 6. This metal is bent on the lines A, B, and C to form the keel and sides. With three angle strips to reinforce it, the bow is soldered together as in Fig. 7. The stern-plate is next fitted on. Now it is ready for the tank. This is made of two circular cans, in the larger of which an air- valve is placed before the two are joined, to form a cylinder 8 in. long and 2% in..in diameter. This is shown in Fig. 8. The ends of the tank are strengthened by a wire 297 FIG.A NOEZLE? ” u call wu WY) TURNED OVER AND SOLDERE AIR TANKS) FIG.2 R- EXHAUST TUBE WASHE " WIRE BRACE FIG9 ‘OPENING FOR 7 WOODEN: WEDGE V OF BUBBLE - TION INSIDE BOW B SEC Speeding a Torpedo with Air from a Bicycle Pump 298 7 Uy: % AG yy pS Popular Science Monthly brace and wood wedges, Fig. 9. Through a hole in the keel, Fig. 5, a 3/16-in. pipe is led from the top of the tank to a brass nozzle. The bubble-way, Fig. 10, is then fastened in place and the strips D, Fig..11, for the tank wires, are fixed to the bottom. At this point the tank may be wired or strapped in, Fig. 12, and the exhaust pipe soldered in the keel. If desired, a pre- liminary test may be made for adjusting the speed of the boat. If these trials are satisfactory, the steer- ing gear and rudder are put in. A hole £, Fig. 13, is punched through the bubble-way 299 the edges of which are turned up with a file. The hood or turtle deck, containing a hatchway to make the steering accessible, is roughly cut out. Beginning amidships, the hood is bent over the tank and soldered along the sides, Fig. 22, the tin being trimmed down to fit the hull. The steering wheel is made from a circle or wire soldered to three wire spokes which in turn are fastened to a tin sleeve, Fig. 23. This slips into the steering column. A gun deck may be added, Fig. 24, and a turned wood or metal gun mounted on it, Fig. 25. A metal clip, Fig. 26, is soldered TUBE FOR RUDDER POST at FIG2S fh ve TOP VIEW a STEERING WH WIRE ROD TIN SLE "i oa pamate eer ge {STEERING COLUMN te PATTERN FOR cun? METAL CLIP FOR FLAGSTAFF ~~ RUDDER | _ TILLER~_&y Ficlo * Ps -_~— 1" omen Ser an | ‘ ee 64 “i yp p ‘4 + i a ‘ He ' 44 HATCHWAY f WITH SLIDE “FIG22 Patterns for making the hull of a boat that represents a submarine chaser, the parts being designed so that a storage tank is placed in the fore part under a turtle deck for supplying the air pressure and hull to take the rudder post, Fig. 14, made of heavy wire. This post, to prevent leaking, works in a tube, Fig. 15. With the tube soldered in, the rudder, Fig. 16, may be fastened to its post. The steering column, Fig. 17, is made and soldered to the side of the air cylinder and connected with the rudder post by a wire rod, Fig. 18. The boat is now ready for the super- structure or casing. First the face plate, Fig. 19, with holes for the steering column, air-valve, and rudder-rod, is fitted in, Fig. 20; then the main and after decks, Fig. 21, to the afterdeck to take a flag. With a coat of enamel the chaser is complete. In general it is better to make cardboard patterns of the hull and superstructure parts before attempting to cut out the tin. It is well to see that the rod connecting the steering column and rudder also works freely before soldering it to the deck.. The several dimensions given are merely sug- gestive. The casing should be fitted to the hull; for your tank, steering gear or some minor detail may differ a bit from the specifications given in the illustrations. 300 Making a Durable Playhouse for the Children HIS is really a young contractor’s job, and the boy building it will have something to be proud of. When complete Popular Science Monthly The setting of the door is no difficult task as the hinges are gained in and the lock attached in the usual way. The win- dow sash may be put in like the ordinary kind or swung on hinges like a casement window. The lattice may be arranged as ecacee Feeeereeeeeeces | ; Sa wk aE WT | FLOOR PLATE ; JOIST SILL ps aye 200 i. “0 16°C, 10. PLAY ROOM ‘ie x cco} PORCH | Se 6 JOISTS Elevation and plan view of a children’s playhouse that is so simple in design that any intelligent boy with a talent for carpentry can as shown it makes an ideal playhouse for the children. The manner of construction is that employed for any house with the exception that it is not plastered or lined in any way, the studs and rafters being exposed. As window and outdoor frames, the door and window sash can be purchased, the actual building is not very difficult. The sills are built up of 2 by 6-in. material, as shown in the detail. The studdings are 7{t.4in.long. A plate is placed on top for the rafters. There will be required 12 pairs of rafters 71% ft. long. The location should be level and stone or brick piers should be built up a short distance for keeping the sills from the ground. The porch is a mere extension of the floor within. Both are built up in one piece. The floor plate is then run across 3% ft. from one end or the line of the house end. The roof extends over the same as’ the floor. The following is the list of materials needed: : 400 ft. of 2 by 4-in. studding and rafter material. 100 ft. of 4-in. flooring. 605 ft. of shiplap sheathing. 30 lineal feet of 8-in. and 30 lineal feet of 6-in. finish lumber. 160 lineal feet of 2-in. strips for the lattice on porch. 130 lineal feet of 2 by 6-in. dimension stock for joists and sills. 8 bunches of shingles. 2 double frames for side windows. I single frame for the end window. 1 door frame. 5 window sash. 3 door. hardware. begin his contractor’s career by building it for his sister shown or in any manner to suit the personal tastes of the builder.—W. E. FRuDDEN. a Durable Water Color Aluminum Paint O make a water color aluminum paint dissolve some gum shellac in borax water strong enough to dissolve the shellac, adding enough bronze powder to make the paint. Add a little aniline for color, if color is desired, or the plain bronze, using a very little glycerine to make the paint more flexible. This paint is bright, durable, and waterproof. | Mixing An Old Cake Tin Makes a Good Watering Pan for the Poultry Yard CHEAP and satisfactory watering pan for the poultry yard can be made of an ordinary funnel cake pan. Secure the pan to the ground by driving a stake through the funnel hole and into the earth. It is easily changed to any desirable spot, cannot be_ tipped over and will serve a dozen or more chicks at one time without _ danger of hurting them.—JENNIE McCoy. Holding stake driven through hole in pan |: Sheet Metal Working Simply Explained III.—One-piece pattern for making a twenty-sided steeple ornament By Arthur F. Payne Assistant Professor Manual Arts, Bradley Polytechnical Institute HE problem for the development of a pattern for a twenty-sided finial is very interesting. Glancing at the drawing of the finial it will appear difficult to lay out a one-piece pattern of tin in such a manner that when it is bent up it will take the shape shown in the finished drawing, but if the drawing is given close attention and study it will be readily seen that all of the twenty faces are of the same size and shape, and that each face is an equilateral triangle; that is, a triangle having three sides the same length. It is necessary to get first a true pattern of one of these faces. The No. 4 face is the only one that is lying flat on the paper, all the others are apparently re- To lay out a pattern for such a finial it is necessary to know first how large the finial is to be when finished. For conven- ience of this problem we will consider one 10 in. in diameter at the widest part. The steps taken in order are as follows: (1) Draw a circle 10 in. in diameter—see dotted circle in upper view. (2) Divide circle into five equal parts and connect these points with straight lines. (3) Pro- ject one of these lines down for the top line of the triangle 4 of the front view. (4) With a pair of compasses and a ruler draw the triangle 4 with all sides equal in length. This is the true pattern for one face. (5) Draw this pattern as No. 4 face in the “full pattern’? and then draw J \ \ ‘ \ 5 yoy i 4 98 Full Pattern y mar enews weeee =, , A pattern in one piece having twenty faces, each of the same size and shape, or an equilateral triangle, to make a twenty-sided finial to be shaped from sheet metal for a steeple ornament ceding from the surface of the paper. When a face is lying flat on the paper, as this one mentioned, it is called ‘‘lying in the plane” of the paper. All such faces are true patterns. the other faces exactly as shown in the full pattern. Cut the pattern out of tin and proceed to bend on the dotted lines. It will be necessary to bend the top and bottom row 301 302 of triangles at an angle of 120 deg. The center row of triangles should be bent at an angle of 72 deg. The bending may. be done by means of a ‘“‘brake,’’ or over a “hatchet stake’ with a mallet. The beginner, learning the trade, will be interested to know the scientific name for such a finial. In solid geometry it is one of a group of forms called “poly- hedrons,”’ meaning many sided _ solids. The word “‘poly’’ means many. A cube is a polyhedron that has six equal faces and its special name is a “hexahedron, “ A solid with eight faces is an. “octahedron.” This finial, the pattern of which is de- veloped, is called an “‘icosahedron,’’ because it has twenty faces. Folding Camp Fireplace Made of Angle Iron NY one who likes to go camping will be interested in these. stoves. The only. tools. needed to make them are a hacksaw, riveting hammer and a breast drill with a 3/16-in. bit. The sides are made of two pieces of angle iron 34 by 14 in. The ones used in making the fire- place illustrated were taken from an old bedstead. The legs are 34 by 3/16-in. flat iron and the bars across the top are from flat galvanized steel 1 by 3/16 in. This is used to hold the sheets of gal- vanized iron together. These sheets may be obtained at any tinsmith’s shop at a small price. One advantage of this style re | 2 le 30" x) ay © oS x i} “ 1“ 2X “ANGLE 1RON? -_— _- LEGS eds UP WHEN NOT IN USE The frame may be easily folded flat so that it can be put away in a narrow place of grid or fireplace is that it folds up com- pactly and is steady when set up, It also has the great advantage of being adjust- Popular Science Monthly able-as to width. The fireplace folds into’ a narrower but longer space than when open. I have found it extremely useful as a stand for an ordinary camp stove when used in a tent; for when it is opened to its full extent it just fits a small iron _ stove.—B. E. DoBREE. Garden Seat with Checkerboard in Its Top — : ARDEN seats of the ordinary bench type can be made to serve a twofold duty by placing in the center of their upper; surfaces a checkerboard design. In the. The checkerbousd on the garden seat outdoor makes checkers an inviting game wood top, squares may be cut out with a chisel or knife and alternate ones painted black. The checkermen can be kept in a small drawer placed under the seat. If a cement seat is made along these lines, black and white square tiles can be set in the cement to form the checkerboard design. In making the seat of cement, places must be provided for screws or ex- panding bolts which must be inserted on the underside at the center for holding the drawer slides—Epwarp R. SMITH. Constituency of Rubber for Side Walls of a Tire HE side walls of a tire must be flexible in order to properly distribute the strains, give resiliency, minimize heat, prevent sharp bending of the fabric,. break- ing and separation. Therefore, it is desir- able that the rubber on side walls of a tire be elastic and not too dense or firm; the kind of hard wear resisting rubber used on the tread is not suitable for covering the side walls. The difference in materials and adaptability for tires may be compared. with automobile and machinery parts—_ some materials are required to possess great strength and some are selected for other qualities, according to their tasks. a x ee a ro Popular Science Monthly Manufacturing Prussian Blue from American Products ‘HE shortage of many colors and dye- stuffs in the United States since the European war has caused a thorough investigation into the means available for the direct manufacture of Prussian blue, which has been and still is in great demand for the production of printers’ ink, dyeing, wall-paper printing, oil color and in compounding colors for many other uses where an intense blue is required. Prussian blue, or cyanide of iron, has hitherto been _ produced mainly from the potassium salts, such as the cyanide and ferro-cyanide, and known in trade as soluble Prussian blue represented by the symbols KFE2 (CN)6, while the insoluble blue is represented by FE7 (CN)18 and FE5 (CN)12. The great demand for this blue coupled with the increasing scarcity of it has caused the price to rise considerably. The production of this valuable color from the potassium salts is out of the question in the United States. This is because the supply of salts from the European market has ceased, and those obtainable are too costly. However, cyanide blue can be made at a very moderate cost from the following ma- terials to be procured in the United States: Sulphuric acid, 66 deg., nitric acid, 38 or 42 deg., proto-sulphate of iron (common copperas) and a product known as cyanide mixture, which consists of a combination of cyanide of sodium, and chloride of sodium, which will yield from 39.2 to 40 per cent of cyanogen. The sulphuric acid and nitric acid are of the commercial variety, not necessarily chemically pure. A number of wine barrels will be required of a capacity of 50 or 60 gal. each, which have been dried and thoroughly coated on the inside with very hot, hard paraffin. The barrels are for use in producing and holding a saturated solution of proto- sulphate of iron called the copperas solu- tion, which is made by impending about 100 Ib. of the iron salt in small sacks attached by nailing to a simple wood frame made so that the ends of the frame rest upon the top of the barrel. The sack or bag when suspended should occupy about two-thirds the depth of the interior. By this means.the sack hangs in the water and must not occupy more than three-quarters of the space within, because the constant dissolving of the iron salt will gradually fill the barrel. As the salt dissolves, a 303 quantity of dirt will be held in the sack while a completely saturated solution will occupy the lower portion of the barrel. The barrel should be provided with a wood stop cock well soaked in hot paraffin placed about 6 in. from the bottom. This will allow for the saturated solution to be drawn off clear and free from dirt. The sacks or bags must be kept full to the brim ; pULLILL i : 1Z A sack or bag to hold the iron salt is hung from a square frame in a barrel with the iron salt, which is readily accom- plished by the use of an iron pail. The cyanide solution must also be prepared for use by employing a clean sack in a barrel of water the same as for the iron salt. In this case about 157 lb. of the cyanide mixture will give 50 gal. of a saturated solution, approximately, much depending on the temperature. The concentrated solution of cyanide should register on the hydrometer 100 grains to the ounce of water. A Baume hydrometer will be required to test the iron solution, which should register 30 or ' 31 when ready for use. This will be equal to about 100 or I10 grains of iron salt to each ounce of water. Several large stone- ware crocks will be required of a capacity from 30 to 50 gal. in which the saturated solution of iron salt is oxidized under heat and acid. This is carried out in the follow- ing manner: Oxidizing the Iron Solution Place 30 gal. of the saturated solution into a 50-gal. crock and pour into it 6 pints of sulphuric acid, 66 deg. Stir the mixture well and heat it with steam, using a pressure 304 of 60 lb. to the square inch. This is done by inserting a 34-in. iron pipe in the solu- tion, allowing the end to go within 6 in. of the bottom. In the course of 10 minutes this will bring the solution to the boiling point, when the steam must be turned off and the pipe removed. | The.next operation is the adding of 8 or 9 pints of nitric acid, specific gravity, 1.38 or 1.42, known as 38 or 42. This must be added slowly to the hot mixture while. a second person keeps it stirred with a long t bKiKy Zw a, The mixture is well stirred while heat is applied by steam through an iron pipe strip of hardwood. During this operation dense red fumes of nitrous acid will be evolved and the mixture will boil vigorous- ly. As soon as this amount of acid -has been added, the solution must be allowed time for cooling, which will require from 14 to 16 hours, when it will be found that the quantity has increased from 30 to 35 gal. This is due to the condensing steam and the addition of the acids. Preparing the Cyanide Blue Place 30 gal. of the cold iron mixture into a tub or stoneware vessel that will hold 50 or 60 gal. and add 10 gal. of cold water. Draw off 8 gal. of the cyanide concentrated solution, add 2 gal. of water and pour it all into the iron solution while stirring the mixture vigorously. Avoid breathing the fumes that may be given off, because they consist of diluted cyanogen gas. Fill the vessel with cold water, cover it and allow it to stand for 24 hours. Upon the addition of the cyanide solution a dense and volu- minous precipitation of Prussian blue will Popular Science Monthly take place. As soon as the blue has become settled at the bottom, the clear liquid must be drawn off with a siphon made of plain iron pipe, care being taken not to permit the blue to be drawn off. This liquid, which still contains a fair proportion of a free salt of iron, may be placed in a suitable vessel for further precipitation. As soon as the liquid has been drawn off, the tub must be refilled with clear cold water, stirred well and allowed to stand for 12 hours, when the liquid may be drawn off as before and thrown away. About six such washings will be required to free the blue from the several soluble impurities. After drawing off the last washing water the precipitant is scooped up and poured into an unbleached muslin bag, which is suspended in a clean barrel in the same way as employed for the iron and cyanide solutions. The remaining blue is washed - out of the tub or crock, placed in the muslin bag and allowed to drain for 24 hours. At the end of this time the contents of the bag must be spread out upon muslin in suitable trays. These should be 3 ft. long, 2 ft. wide and 4 in. deep. When filled they are placed in a drying room like drawers in a file where steam may be applied for heating it to a high temperature. The room should be well ventilated so that a current of air coming in at the bottom will pass out at the top after circulating about the trays. This will evaporate the moisture left in the blue. As soon as it has dried thoroughly it may be ground to a powder in any suitable mill and it is then ready for the market. . If tubs are used in the process of pre- cipitating the blue they should be well dried and the hoops tightened before they are used and the interior coated well with amyl acetate collodion by flooding and draining, or a solution of rubber cement that has been thinned with benzine or benzole may be used. This coating will preserve the interior against the action of the chemicals. The tubs must be well water-soaked previous to use until all leaks have ceased. The stoneware vessels need no preparation. If it is desired to manufacture this blue on a large scale care must be taken to get rid of the fumes resulting from the addition of nitric acid to the hot iron solution, because of their poisonous properties. Proper ventilation and respirators will protect the workers against any danger in handling the mixture. Popular Science Monthly A Plumbing System for the Farm Residence HE important points. to be considered. _im the arrangement. of a. plumbing system are durability of material and construction, and simplicity. Avoid any yams ag of pipes, and arrange the water pipes so as to carry the water to the point of discharge in as nearly a straight line as possible. The use of lead pipes or lead lines and receptacles for drinking water should be avoided in small private systems. | The main pipe from the supply system should be about 114 in. and never less than I in. in diameter. It leads to the kitchen range and then branches.. One branch conveys water through the heater, through the hot water tank, and thence to the hot water fixtures. run parallel with the cold water pipe, but should not be so close to it that the temperature of either will be affected. The arrangement of water. pipes, hot water tank, etc., is. shown in aeons asaeneae The hot water pipes should: 305 of travel for the hot: water is upward, and this should be aided, im arranging the hot water pipes, as much as possible. : The sizes of the pipes generally used for supplying water to the various fixtures are given in the table below: All water pipes should have sufficient slant to drain them back into the tank or drainage system, and a drain pipe and'cock should be provided at the low point in the system, so that in extremely cold weather the system may be drained into the sewer or { FLOOR CEILING? s" I Ss) I eee 7 £ 7 ‘HYDRAULIC GAGE era's _)"" 28 Ba the illustration. The hot water pipes are shown in black. — All water pipes. should be put in with red lead in the threads of. the joints. and all fittings should be screwed up tight. The natural direction - Low HIGH SUPPLY BRANCHES ested Ee aloes ‘ INCHES INCHES mer ain higrgeiatialel ee. “oe Bid i vary. To water closet flush tank. . iy %ae—-¥A To water closet flush valve. . 1 —1%| %— 2 To water closet flush pipes. . | | tyes % iii To kitchen: sinks te Fe Se ci $3 5 To pantry sinks. .......... 4a— % Le % To:slop sinks............. 5 4a) % e— 4— 341 K—e- *. The arrangement of water pipes and hot water tanks for a plumbing system in which:a pressure tank is used to force water through the pipes drainage system to prevent freezing. This necessitates a stop-cock on the pressure- tank outlet to prevent draining the tank. Pipes should be kept from the outer walls to prevent freezing. Those located where they are in danger of freezing should be boxed. in. sawdust or some other non- conducting material. Since a plentiful supply of hot water is desirable and a large quantity, retains heat for some time, it is well to provide a fairly large hot-water tank. However, the size of boiler depends on the existing condi- tions, such as the water supply and, the size of the building. A safe rule istoallowa35,or 40-gal. boiler to a building having one bath- 306 room. Add 30 gal. additional capacity for extra bathroom. A water back having a heating surface of 100 sq. in. is sufficient for a 40-gal. boiler. ae Boilers should be galvanized inside and out, particu- - larly inside. Copper boilers are preferable VENTILATION if properly coated inside with block tin. Theseareclass- ed as light, SOIL PIPE 4"—+ t 2"° STORY = 4" : a LN ay = caesar. 4 Oe KITCHEN } STORY ; - BASEMENT H ; LAUNDRY ; TO. SEWER 1 aa 4" A drainage system of a residence to carry away the waste from the sinks and bath heavy and extra heavy, the latter being tested to 150 lb. water pressure. Ordinary steel or iron boilers are tested to 150 lb. water pressure and extra heavy ones to 250 lb. pressure. The latter should be used when the gage pressure is more than 40 lb. per square inch. Sewer Plumbing The sewer plumbing serves as a drain for the water plumbing. The drainage system Popular Science Monthly should be so constructed as to carry away completely everything emptied into it, and it should be constantly vented, frequently and thoroughly flushed, and have each of its openings into the house securely guarded. All drains, soil pipes, and waste pipe should be water-tight and air-tight. NAME OF PIPE DIAMETER Main and branch soil pipe............ 4 Main Waste pipe. «ie :icicuteseaines teewee 2 Branch waste pipes for kitchen sinks. . . 2 Bath or sink waste pipe.............. Basin waste pipe. . «4.40. .2s Gant 14—1\% Pantry sink waste pipe. .............. 1% Water closet tran. 055. 29. nds @ananee 34-4 Wash tubs. Traps for two tubs...... 1%—2 Waste pipes for three or four tubs. .... 2 Main vents and long branches........ 2 Branch vents for traps over 2in....... 2 Branch vents for traps less than 2 in... 14% The soil pipe, or house drainage main, begins at the sewer opening and passes up through the house as nearly vertical as possible and out through the roof for free ventilation. It should be at least 4 in. in diameter, of extra heavy cast iron, and all joints should be tightly calked with lead and oakum. All discharge from the wash basins, sinks, and toilets empties into the soil pipe, and connections should be tightly made. The sewer inside the basement wall should always be soil pipe; tile should never be used except outside of the wall. A soil-pipe trap should be provided at the house foundation as shown. Every fixture should have a trap to prevent foul air from coming back through the waste pipe. Vent pipes should be provided on all waste pipes to prevent siphonage and the con- sequent destroying of the traps. A good arrangement of sewer plumbing is shown in the illustration. Note the traps and vent pipes on each waste pipe. The smallest sizes of waste and vent pipes are given in the table above. All plumbing should be tested by filling with water or smoke to detect leaks. AN ANNOUNCEMENT Owing to the fact that the last chapter on Winning an Athlete’s Laurels covers all indoor events and does not contain any special features for this season of the year it will be concluded in a later issue, or one of the early winter month’s, at which time all outdoor events will be discontinued and the athlete will be interested principally in something tooccupy his leisure time indoors. a ee | / A Quick Action Electric Switch for Photographers’ Use N doing some work around my dark room I felt the need of an electric switch which would work more swift- ly and easily than those sold by sup- ply houses. The * illustration shows a single _* pole switch that S&S met my demands for something delicate and in- stantaneous in action and it was constructed quickly. The base A was made of well shellacked wood 4 in. long 2 in. wide and ft in. thick. The hinges B fasten the block C to the base block A. The block C is about 24% in. long and about 1% in. wide. A handle D is fastened with screws to the piece C. The two terminals E consist of brass screws and washers on pieces of bronze or copper. Across the face of the block C is a strip of bronze tacked in place with small brads. Closing the block C brings the strip of bronze in contact with the terminals E which com- pletes the circuit—VirciL R. THARP. A quick acting single pole single throw electric switch Making an Electric Searchlight for a Motor-Boat RELIABLE searchlight is a necessity for motor-boating at night, especially in crowded waters. The searchlight illus- trated is for use on small craft not equipped with a generator and is operated indepen- dently of the ignition batteries. For the light unit, purchase one of the hand lanterns that operate on one dry cell. Many types are on the market, but for this use it is necessary to select one with a large reflector. Procure a tin can into which iE Amateur - | Electrician Zs ‘And Wireless Operator the reflector of this lamp will snugly fit. To this can rivet a swivel arrangement, as shown. It is made from %-in. nickeled pipe fittings and it consists of a flange, tee-joint, two ells with flanges and three short lengths of pipe. The flange is riveted to the side of the can and a hole is punched in the can so that the wires which come up through the piping may pass through. The reflector and lamp are connected with the wires, a switch on the back of the can forms a handle to move the search- light, and the reflector is soldered into place. The flanges on the ells are screwed to the deck and a hole is bored under one to pass the wires through. The wires should be well taped to prevent abrasion and a short circuit. The battery for this light consists of two or three dry cells connected in parallel. The cells should be placed in a wood or pasteboard box, connected, then com- pletely covered with melted pitch or paraf- fin. This effectively prevents short circuits and prolongs the life of the cells by her- metically sealing them. The wiring be- SWITCH lt F_ LOOSE THREADS ALLOW TURN- Bish. ING OF LAMP An electric searchlight for a motor-boat wherein only dry cells of battery are used tween the batteries and light should be rubber-insulated. The light thrown is very powerful. If three batteries are used they will usually last a whole season. This is due to their parallel connection, which splits the load and lengthens the life. The light on a whole is neat and serviceable. A good 307 308 effect can be obtained by lacquering the container black and polishing the nickel parts——TuHomas W. BENSON. A Simple Arc Lamp Using a Thermostat Control HE novel part of this arc lamp is the application of the active part of a thermostat for its control. A piece of i O) i ve DIAGRAM One carbon-holder base is constructed of — two metals to produce thermostatic action asbestos board 1% in. thick makes a good base. To this is attached a ring-bolt for hanging the lamp. From copper tubing, 1% in. outside diameter, cut two lengths each 2 in. long. A hole is drilled through the wall of each tube and threaded for a 14-in. bolt. One of these tubes is soldered to a strip of copper and clamped into position on the base by means of the binding post. The other tube is mounted on a _ heat-controlled strip formed by riveting together a piece of brass and a piece of sheet iron. The rivets should be spaced % in. apart. Around this strip wind mica and then a single layer of No. 18-gage German silver wire. One end of this wire is led to the strip and the other to a binding-post. The carbons are slipped into the tubes and held there by screws. The two carbons are bent toward each other so that they touch. Care should be taken in mounting the com- pound strip so that the brass is next the asbestos base. The operation will be clearly understood from the illustration. As soon as the cur- rent is switched into the arc it heats the German silver and causes the compound strip to bend, thus striking the arc. If the strip bends too far and breaks the arc add more wire and experiment in this manner until the arc burns steadily. It would be advisable to protect the strip from the heat of the arc by a shield made of asbestos board.—THomas W. BENSON. short circuited winding, Popular Science Monthly How to Make Slow Acting or Sluggish Relays RACTICALLY all electrical circuits, and especially telephone and telegraph circuits, require relays. In _ telephone work especially, where several relays are used in one circuit, it is necessary that some of them shall be slow acting or sluggish. Such relays are used in circuits for a variety of purposes, the most important ones being: First, to prevent temporary disturbances in one part of a circuit from affecting some other part. Second, to secure a certain time interval between the operation of different parts. of.a circuit. A relay in itself is not generally slow operating or slow releasing but such features are determined by a combination of the design of the relay itself and of the circuit in which it is used. Relays may be made sluggish in a num- ber of ways. The first is to equip the. relay with either a heavy copper head at one end of the spool or a copper tube over the core the full length of the winding space. This is equivalent to a closed circuit winding having a single turn of very low resistance around the core. Similar re- sults could be accomplished with a regular although this would not be as effective as the copper head or tube. It has been found that the copper head is more effective with tubular type relays, while the tube over the core is more effective with the return gravity armature type. The use of either the copper head or tube results in any change in the field setting up an induced current in the short circuited winding in such a direction as to oppose the change in the field. Such an induced current will be of very low voltage as there is only one turn around the core,’ but of high amperage due to its low resistance. If the thickness of the copper head or sleeve is increased the resistance of this closed circuit will be correspondingly lower, and hence the induced current will be stronger for any given operating current. The operation of every relay depends upon a certain magnetizing force known as ampere turns and is the product of the number of turns in the winding and the current passing through it. If the winding and operating ampere turns. are so chosen that the relay receives just enough current to operate it, the field will not become strong enough to move the armature until the effect of the short circuited winding has Popular Science Monthly - been overcome and the field reaches its maximum strength. Such a relay will be slow in operating but may be made quick in releasing by choosing such a design that the releasing requirement will be high compared with the operating requirement. If the winding and operating require- ments.are so chosen that the final value of the magnetizing force which the relay receives is much greater than the releasing requirement, then the relay will be slow releasing, as the magnetizing force will not decrease enough to allow the release of the armature, when the circuit is opened, until the effect of the short circuited winding has been overcome. Sucha relay may be made quick in operating by choosing such a design that the releasing requirement will be low compared to the operating require- ment. In neither of the above cases is the rapidity of the movement of.the armature itself greatly lessened, the greater delay occurring between the time of closing or opening the circuit and the beginning of the armature movement. The: above con- struction is sometimes used for making a relay. that will not readily respond to alternating current. A second. method. is; to use an external inductance or a non-inductive: resistance which come under the classification of circuit design rather than the design of the relay itself, except where the non-inductive shunt is wound on the relay merely as a matter of convenience. Either of these means is used to cause the current through the winding to rise or fall more slowly than it would if no outside means was used to affect this time interval. The non-induc- tive shunt slows down the time of release but has practically no effect upon the time - ofoperation, while the external inductance. slows down the time of operation but has practically no effect on the time of release. Both effects may be accomplished by the use of the two in combination. As in the case of the first method the movement of the armature itself is not actually retarded. The action of such an arrangement is to increase the time between. the closing and opening of the circuit and the beginning of the armature movement. A third. method is, to make the moving parts of the relay heavy so that it will be slow in responding to changes in the magnetizing force. If the operating cur- rent is just great enough to. pull up the armature, the relay will be slow. in operat- 309 ‘ing.*: Fo make sucha relay slow in releas- ing, the restoring force, whether gravity: or a spring, must be as small /as- possible and still cause the armature to fall back. Contrary to methods 1 and 2, with’ this construction the actual movement of the armature is’ retarded. Such relays are used extensively on alternating current; as their heavy moving parts prevent the opening of the relay contacts during the reversals of the current. The circuit conditions in each’ case determine which of the above’ methods should be applied, although the first and second methods are the ones: most com- monly used. In some cases: two of these methods are used on the same relay to meet certain peculiar circuit con- ditions.—F, H. Timtotson: Reversing Rheostat for Controlling a Small, Motor T is often desired to reverse: the direction of rotation of direct current motors and at the same time adjust the speed to suit the new condition of operation. A service- able controller may be made as shown in the sketch. The sets of contacts A, B, and C, should be of brass or copper, and mount- ed on a slate slab 12 in. square. The re- sistance coils R should be fixed to the back of the slate board. These coils, made of LINE BRUSHES FIELD A reversing switch in connection with a rheostat for controlling a small: motor German silver, should. have sufficient re- sistance to give the proper: speed control without over-heating. Along the edge of the slate six binding posts .are arranged and connections: made, according to the diagram, on. the reverse side of the panel. The switch arm.D may be made from wood., The brass.spring contacts E and F are connected so that 310 they will establish a circuit between the line of contacts A and B. The arm contact which presses on C is connected with the handle swivel and in turn with one of the binding posts. It can be seen that when the handle is in the neutral position, no connection is made with the motor. Moving the handle to the right. or left causes the motor to ro- tate either one way or the other. accomplished through a reversal of the field connections. After a direction of ro- tation is established, the speed is varied by progressing the switch handle from notch to notch on contacts shown at A in the diagram.—K. M. COGGESHALL. An Ingenious Wiring System for Two Inductive Transformers ‘THE accompanying diagram shows a very good wiring system for the experimental set. Five different connec- - tions are possible for the two inductive Circuit | x lc A | B | . Transformer Fig. 1 Mees. ox vet os out |down| up | out] up Transformer Fig. 2 2 aie ir ekna down] out | out |down|down Fessenden interfer- ence preventer..| ‘“‘ |down]| up | “ up Selective tuning. ..] out | “ |down| up [down Long wavelengths| ‘ | up | up |down] up Tabulation switch positions for the various circuits shown in the diagram of the wiring couplers by using five single-pole, double- throw, knife-switches. The inductive couplers are shown in Fig. 1 and 2, A, the Fessenden interference preventer, having the two primaries connected in multiple and the secondaries in series; B, the selective tuning with the secondary of the first in- ductive coupler connected with the primary of the second; and C, a long wavelength ‘‘*hook-up”’ with both the primaries and the secondaries in series. A variable con- denser with short circuiting switch D may be placed in series with the second primary, and another with open circuiting switch E may be added to time the secondary. The This is — Popular Science Monthly connecting wires should be of No. 18 gage lamp-cord as short as possible. A throw of the switches will tell which of the two transformers is the better. It is a good plan to have two detectors as shown AERIAL FIG. DETECTORS TRANSF. a . °) oF ete & ya | H | a : ; a D rE ef VGs ‘ b Z V0.2 A TRANSF = ee! GROUND FIG 2 Very satisfactory wiring diagram of two in- ductive couplers for an experimental set > f BLOCKING COND. connected with the switch F for the sake of comparing the different minerals, and also in case one gets ‘‘knocked out’’ in the middle of a message.—HAarveEy N. BLIss. A Variable Condenser for a Radio Receiving Set HE average amateur, in constructing his own wireless receiving apparatus, encounters his greatest difficulty in mak- ing a good variable condenser. A simple tubular condenser is shown in the illus- tration. It is easily constructed. The base is preferably of oak, 14 in. long, 3 in. wide and ¥% in. thick. The ends which hold the large cylinder are each 2% in. square and in. thick. The brass pipes are 6 in. long and 114 in. in diameter for the If BRASS PIPE. 'LONG BRASS PIPE. G'LONG A tubular condenser, if properly constructed, will serve just as well as a plate condenser large one and 1 in. in diameter for the small one. A wire soldered to the stationary tube is connected with one binding post and a flexible cord which is soldered to the mov- able tube is connected with the other bind- ing post.—THomas LEE HopGEs. Popular Science Monthly A Drip-Pan Alarm for the Ice-Box Drain HE illustration shows a very neat and easily constructed drip-pan alarm which can be made by the home worker at a very slight expense. A small piece of glass tubing is run up through a cork float, on top of which is secured a light round copper washer. The cork with its guide hangs down into the pan from the under side of the base-piece of the re- frigerator as shown in the illustration. 311 An Amplifying Electrostatic Radio Receiver N THE development of radio telegraphy inventors have constantly striven to produce detectors or receivers which would be not only sensitive, but also rugged and easy to adjust and to keep in adjustment. Some of the instruments in common use meet these requirements, but in general the more sensitive of them are rather deli- cate in operation and seem likely to be rendered inoperative, or at least less m1 _fi fi sii Hh st Glass tube beet =e al SR. eee a \ 4— = ly © WesSs/ | 8 Y + ) rat Old dry battery Tx contact connections Door bell batteries nab SS eta \ ca G i ae To door bell eT | B _ It will be noticed at A that the perma- nent contact points or wires are so high that they in no way interfere with the sides of the pan when it is withdrawn to be emptied. The batteries of the door-bell circuit are utilized to operate the buzzer or bell of the pan-alarm, as at B. Asimple one-point switch is placed in the circuit for con- venience if the pan cannot be emptied at once, the contacts being so arranged that the alarm will sound continuously after the water is within 1 in. of the top of the pan.—F. W. BENTLEY. Treating Cardboard Tubes for Tuners on Wireless Apparatus A. GOOD way to make a cardboard tube non-shrinkable is to give it several coats of varnish before commencing the winding.—CHARLES WILDINGER. The cork float details and the manner of hanging it to the underside of a refrigerator to sound “a bell when the drip-pan is about full and there is danger of it overflowing sensitive, by receipt of loud signals or heavy strays. It has often been said that a wide departure from present principles would be necessary before an ideal receiver could be produced. A device shown in 1916, United States patent to R. A. Fessenden, number 1,179,906, is interesting in this connection. A diagrammatic view of this instrument shows that the apparatus consists essen- tially of a combined electrostatic telephone and amplifying carbon microphone. The antenna I is connected through the tuned transformer primary 2 to earth 3, and coupled to the primary is the secondary coil 4. A secondary loading coil 5 is in series with this last-named inductance, and both are shunted by the static receiver con- sisting of the thin movable diaphragm or plate 6 placed close to, but not touching, the fixed plate 7: Baie on Rt 312 The moving plate is pivoted on a vertical arm supported by two horizontal wires under tension, whose section is shown at 8, 9, and which are in turn held by the frame 10. The lower end of the vertical A combined electrostatic telephone and car- bon microphone that is sensitive and rugged arm carries an electrode which dips into the carbon granules of the differential microphone amplifier 11. This variable- resistance cell has two opposing contact surfaces 12 and 13, and is in circuit with the battery 14 and the divided primary winding of the telephone transformer 15, 16. The telephones 17 are connected to the secondary 18. In operation the supporting wires are stretched to the tightness which tunes them to vibrate at the group frequency of the desired incoming signals. Currents in- duced in the antenna by the arriving waves produce opposing charges upon the plates 7, 6 and cause an attraction. This moves the lever toward the contact 12 and away from 13, so changing the current in both branches of the primary of the telephone transformer. By suitably winding these two coils the effects upon the secondary are made to add, and the change of current resulting in the circuit containing the telephone causes it to respond. By this resultant action it becomes possible to secure responses to comparatively weak signals of the desired group frequency, while interference of other spark frequencies is largely reduced. The same apparatus may be used on the heterodyne principle, by adding a local source of sustained waves which will inter- act with the incoming signals to produce musical-toned beats. In this case the sen- sitiveness of the device is still further in- creased. The tension of the supporting wires is adjusted to the pitch of the beat-note. Popular Science Monthly Strong Wireless Signals in Winter Time SERIES of tests lasting over two years were completed some time ago, with the object. of finding out how much stronger radio signals between two selected stations would be in winter than in summer. The test signals were sent nearly every day during that time, and the amount of power sent and the intensity of signals received were carefully measured. It was found that the best time of year was from November to February, and that then the messages were about six times as loud as during the months from May to August. A Testing Set That Does Not — Use a Battery HE testing set illustrated, which does not use a battery or magneto in the circuit, is novel and interesting. The current used is set up by the action of the saliva on the zinc and copper plates. While — it is not recommended for constant use it can be worked in case of emergency. .'°’ The mouth piece is made of wood of fiber cut tapering at one end. It is aboiit 2 in. long, 44 in. wide and 14 in. thick. A piece of sheet zinc is cut 2 in. long and 4 in. wide, also a piece of sheet copper of the same dimensions. These metal strips are fastened to the edges of the insulator so that there is no contact between them. Solder a small screw-eye on the outer end of each piece of metal for terminals. The current for making the test is set up by the action of the saliva on the metal Connect a single head receiver in series as shown and place the block in the mouth. A distinct click may be heard when a clear circuit is made.—ALBERT FERTICK, Popular Science Monthly How the Radio Inspectors Trapped a Disorderly Amateur pet: before Secretary of the Navy Daniels issued his order for the dis- mantling of all unofficial wireless stations, the Government radio inspectors about New York found it necessary to track a disorderly amateur who continued to send An automobile was used to carry about a simple loop direction-finder out false ‘““S O S” signals. Their method of running down this amateur is of especial interest now that we are at war. The false distress signals were sent out every night or so. Luckily the wavelength was short and ships at sea did not hear them. But the Herald wireless station and the Brooklyn Navy Yard did. Recog- nizing the signals to be the work of an amateur, they immediately reported to the authorities, and Louis L. Krumm, chief radio inspector of the Department of Commerce, started on his track. He first acted upon a hint from the Herald operator who explained that he could hear the sig- nals more loudly on his own apparatus in Brooklyn than on the sensitive instruments in the Herald station in Manhattan. This at once confined the search to Brooklyn. To locate the transgressor ex- actly, a small directive-loop receiving set was “hitched up” in an automobile which was run about the Brooklyn streets. The wire loop was about four square feet in area, and could be turned about to face in any direction. The circuit of this loop was closed by the ordinary condenser and coupler secondary of an audion receiv- ing outfit (see illustration at right). Starting from a given point in Brooklyn, the inspectors found that when the plane of the loop was turned in a certain direction the “S O S” signals were heard most plainly. This meant that the amateur’s 313 station lay somewhere along that direction; for, as every amateur should know, when a wireless wave passes through a wire loop end-on, the electromagnetic lines of force will induce a certain current in one vertical wire of the loop, and a different electric current in the other vertical wire, the resultant current flowing around the loop being equal to the difference in these two induced currents. The reason why the two induced currents are different is shown in the diagram on the follow- ing page. At A the lines of force pass through the loop end-on, and the intensity of the lines of force cutting the vertical wire nearer the sending station S is less than that of the lines cutting the other vertical wire, causing a corresponding dif- ference in the two currents. Obviously, the resulting current flowing in the loop is a maximum and the signals are heard the loudest when the loop is pointing directly towards the sending station, as the loop at A is doing. At C, on the other hand, the two vertical wires are equally distant from the station S. The same current is induced in the two wires, since the same intensity of the lines of force are cutting them. The induced currents, on ‘‘bucking”’ each other, are simply neutralized and no resultant current will affect the audion detector coupled to the loop. Now that the radio inspectors knew one line of direction to the amateur’s f WIRE LOOP ROTAT ABLE 7eSPINDLE POINTER STATIONARY £2 ke SPINDLE =S}—A--SUPPORT. AUDION RE- {| ceiving A CABINET ROTATABLE eDInn SPINDLE SCALE With the regular audion equipment, a wire loop was used instead of an aerial ground station, they immediately proceeded at right angles to this line of direction; as from A to B indiagram. At B they de- termined a new line of direction to the culprit by again turning the loop around 314 to the point from which the signals were heard most clearly. Then 'they knew that the amateur must be located at the point where these two lines of direction inter- sected ! 5 After repeating their maneuvers many Position of loudest j receiving \> “ee Position of zero: receiving Diagram illustrating the principle em- ployed to locate the sending station times, continually getting nearer and nearer to the unsuspecting amateur, the inspectors found themselves within a block of his station. The rest- was easy. There was only one antenna on that block from which the signals could come. The arrest of the youngster followed. Needless to say he has been taught a lesson and is not likely to cause any further trouble. How to Make a Kick-Back Preventer for Wireless Apparatus N many instances where a wireless set is employed for sending purposes the fire underwriters require a kick-back preventer. OV MAINS SAFETY GAP =6 FUSE FUSE) ak | GROUND SIDE ‘The several instruments are con- nected as shown to make the kick-back preventer effective POWER TRANSF al This piece of apparatus is, in some cases, expensive to purchase; but it can be easily made, at little expense. . ; The essentials are a 16-C.P. carbon filament electric-light bulb, with a socket to fit it—a Mazda bulb will not do—two fuse- Popular Science: Monthly blocks and fuses, three binding-posts with holes in the center to admit pieces of copper wire, and a baseboard on which to fasten the apparatus. The binding-posts are used for a three-point safety-gap. The several instruments must be carefully con- nected as in the diagram, or the coil will not work. ¥ ‘This device is intended for 110 volts with grounded power line. To find the grounded side of the line take a 110-v. bulb, with wires attached, and connect one wire with the ground and the other with one of the mains. The bulb lights only when it ig connected with the other main—not with the grounded side. ey | In using this kick-back preventer, when the key is pressed the bulb will light up and the coil or transformer will operate. In case of a kick-back this device will send the excess current into the ground, and will save the coil and fuses from burning out. — Variable Primary Coil Using a — Switch Instead of a Slider i winding tuning coils for long wave- lengths, if the slider runs the. whole length of the tube it causes extra labor and expense. The following plan may be a ae a a Switch points used instead of slider contacts on a vertical primary coil used to prevent it from doing so. Scrape a few inches of the wire and use a rod of the length designated. At intervals equal to the length of the scraped wire take off taps and run leads to switch-points. The finished coil is manipulated in the same way as the primary of a Navy type inductive coupler.—GLENN DUNFEE. A Use for Discarded Cylindrical Food Boxes YLINDRICAL cardboard boxes, such as certain food products are packed in, make excellent forms upon which to wind tuning coils. By using two, one of which is slightly smaller than the other, a very satisfactory inductive coupler may be made.—Epwarp McCLure. Popular Science Monthly 315 CONDENSER pols oped TELEPHONE TRANS- MITTER TRANSFORMER America’s New Semi- Wireless System for Telephoning from Captive Balloons 4 Wiest will be still another addition to thelong list of America’s contribu- tions to the technique of modern warfare is a wired-wireless system for communi- cating from balloons. The gun-fire of artillery is directed, as everybody knows, battery commanders who ascend to high altitudes in anchored balloons. From here the commanders take their observa- tions and telephone their orders down to their batteries which may be concealed several miles away. To provide suitable telephone transmission lines, the Allies have been using the wire cables which anchor the balloons. They have built these cables up with an internal steel core which they insulate from the outer strands. But in providing two insulated conductors in this way, they were com- pelled to use a bulky, very expensive cable which was likely to be rendered, worse than useless if too roughly handled. For if once this cable should become injured and the two conductors become short-cir- cuited, the telephones could not work and the commander would be cut off from his men. The semi-wireless system which has just been brought out by William Dubi- lier and Robert Goll, two American engineers, does away with any need for the internal core. Their system, which is fully protected by patents, is expected to be officially adopted by our Govern- ment. For connecting paths between the balloon and the ground, the new system uses an ordinary solid steel cable as one path, and the air itself as the other. It therefore uses one transmission line, as in wire telephony, and it also uses the air as in wireless. Considering the diagram of con- nections it will be seen that the system has one secondary circuit consisting of the secondaries of the two telephone transformers, of the two telephone receivers and their shunt condensers, and of the two metal sheets which, with the air~ be- tween as their dielectric, form a balanc- ing capacity. This one secondary has two primaries: the telephone transmitter, batteries and the primary of the trans- former, in the basket, and the similar instruments down below at the gun battery. The three circuits are mutually tuned to provide a maximum of current in the secondary. When the commander talks into his transmitter, the corresponding primary current is modulated accordingly. The variations in the primary currents are induced into the secondary through the step-up transformer. Here the variations become very marked, due to the strength- ening effect afforded by the inductance of the transformers and the capacity of the air-condenser, which together natur- ally tend to cause the secondary current to oscillate. These variations are changed into sound waves by the telephone re- ceivers—and the gun captain thus re- ceives his orders. A Polarity-Changer for Reversing Lighting Battery Current OME audion detectors work better if the current from the lighting battery is reversed. Todo this quickly a polarity- changer is very handy. There are many kinds of polarity-changers, but the one here described is very compact and looks neat. To make it, mount five contact points on a fiber-base as shown in the drawing on the following page; space them about half their diameter apart. The positive side of the battery is connected with No. 1 and 5; the negative with No. 3, while No. 2 and 4 are connected with the fila- TRANSFORMER TRANS- 4 MITTER ty i CONDENSER i BATTERIES ike SS “TELEPHONE METAL SHEET BALANCING CAPACITY SS H,—, 316 ment and rheostat in the circuit. . The two brass contact-arms on the switch-handle are insulated from each: other: and: are of, the edgewise-contact type. They should be made of thin spring-brass and split at the end as shown, so: that:each blade will make perfect contact with two points at a time: The switch-arms are fastened: to: the handle. by laying them om the back of the insulating To filament and rheostat A polarity changer for reversing; a cur- rent taken from..a lighting battery circuit handle in their proper position, placing over them a fiber-washer and drawing it up tight against the blades by means of a nut screwed on to the bolt through the handle. Adjust the knob so the ends of the blades strike the contacts in the center. Then adjust the blades so that when one arm is in contact with No. 2 and 1, the other is in contact with No. 3 and 4; and when one connects. No. 2 and 3 the other connects 4 and 5. Care should be taken to see that all contacts are the'same height and alli equally spaced; for then it will be easy to get each arm to touch two contacts. A good holder for the handle is made of an old: binding post which has) a wide: base. Force the post into a hole in the base with the: base projecting, in order to keep it from going clear through. The shaft on the handle is then screwed: into this until the contacts are made certain by the pressure of the spring... Be sure that a good: contact is made, otherwise the instrument will be inefficient.— FRANK SAHLMAN, A Simple and Dependable Multiplication Method N interesting and simple method of multiplication is performed as follows: Suppose, for example, that it is desired to multiply 145 by 39. Write 39 in one column, 145 in a second. Divide’ 39 by 2, _ the required product. Popular Sevence Monthly neglecting the .remainder, .and multiply 145 by 2; write the first result i in the first column, the second result in the second. Continue the process of dividing the num- ber in the first column by 2 and multiplying the number in the second column by 2 (always neglecting the remainder if one occurs in the division) until the number in the first column is 1. Then strike out all of the numbers in the second column that are opposite even numbers: in» the first column and add the numbers remaining in the second column. The result will-be The work for this problem is shown: The method ees on. the: fact. that any number may. be expressed,as the eae _of powers. of 2 (including 2° = 1).. number 39, for instance; is. Bese sd 2° + 21+ 2? + 25, that is, ee The numbers. remaining in the sec column are I x 145, 2 x 145, 4 Xx 145, and 32 x 145,.so that their sum is. :, to. 39. x. 145.—Paut R. Riper, P Ph.D., In-. structor in Mathematics, Yale University.: An Insulation for Secondary: Terminals on Transformers HE insulation of secondary terminals on home-made. transformers. is. often very. poor, resulting in leakage and low- ered efficiency. The hard rubber shells from telephone re- ceivers. can be used in such cases. with excellent results.. The shells should be: mounted as. shown in the illustration. A long brass rod threaded on both Z@&@ ends is run com- pletely through the device and clamps it firmly in posi- tion. | Connections are easily made with both ends of this rod. Method of mounting the. shells for insulation Wireless Work in Wartime—I. The beginning of a series which will cover every present-day application of the principles of wireless By John L. Hogan, Jr. N military and naval warfare there are l many times when no man is of more importance than the radio operator. Upon his speed and accuracy, and on his knowledge of the principles of his appa- ratus, may depend the failure or success of great strategic moves. Radio amateurs and operators, as well as those who have an aptitude for this work and are now taking it up, are indeed fortunate in having the opportunity to serve the Nation so well in the present crisis. Radio operators are needed in the Sig- nal Corps of the Army and in several branches of the Naval service, including the new fleet of submarine chasers now being equipped. The call for men to take up these classes of military work willleave other positions open, particularly with the commercial radio or- ganizations, positions which probably can be effectively. filled by competent women. There is and will con- tinue to be a demand for skillful wireless op- erators, both experienced and newly trained. Tiit ae Lijit ! i Srxe- TOMO yp | Fundamental Knowledge The fundamental knowledge which all radio operators must possess relates to the use of the Continental or International Morse code. It is absolutely essential to be able to send well-formed Morse char- acters rapidly, and to have the ability to write clean ‘‘copy’’ when receiving signals from a distant station. Without this ability none can claim to be a radio oper- ator. And of only slightly less importance is the understanding of the basic principles of the apparatus used, together with the ability to adjust it quickly and accurately. This first article will take up the study of the code, pointing out not only the best and quickest way to learn it but also the elements which characterize good and bad sending. Just as many engineers fail to FIG. 1 Letter chart with dots and dashes plotted on cross section paper to show length of spaces appreciate what is going on inside their instruments, so many operators fail to realize that there are good reasons for a number of rules of sending which appear unimportant at first glance. Either atti- tude leads to results which must necessarily be poor when compared with what is attainable by a little careful study. It has been stated as a general rule that men and women who have a feeling for musical rhythm make the best teleg- raphers. It seems curious that the same quality of beating time enters so strongly into both music and teleg- raphy. A keen time- sense, or the ability to note and correct small variations in time in- tervals, is of extreme importance to the tele- graph operator. This is because the tele- graph signals are sent by turning electric currents on and off for definite times. The elements of the Continental code are dots, dashes and spaces. Spaces of various lengths are merely periods of idleness, when no current is turned on. They occur between letters and between words, as well as in separating the dots and dashes which combine to form each character. The dot is the short active element, and is formed by turning the current on for a brief time; the dash is a longer active element, made by allowing the current to flow about three times as long as for a dot. Various combi- nations of dots and dashes stand for the various letters of the alphabet, and words in any language are spelled out letter by letter. A =a ae ame ee TT Tit | N<&xXE —» — > 8 ee <5 <> ——————— —.e = <> BS. J 322 _ Popular Science Monthly Vol. 91 No. 3 239 Fourth oehee: New York City September, 1917 $1.50 Annually Why Not the Land Torpedo? Mount it on an automobile; open the throttle wide; and let the machine rush to the enemy’s trenches HE submarine torpedo is the most. destructive weapon of the sea. Then * why not a land torpedo? A cheap vehicle could be made to carry a high- explosive mine, a huge shrapnel, or a mis- sile which would be a combination of both. Where necessary, provide the vehicle with caterpillar wheels and with a wire-cutter, and dispatch it toward the enemy, over shell craters and through entanglements into the opposing trenches. There the arge could be exploded, and the men and operty within blasted into oblivion. {| The originator of this plan is Felix bah, of Philadelphia, whose idea as he as conceived it is illustrated in action. fhe ground of ‘“No-Man’s Land” being lat, ordinary gasoline automobiles of small ze are used. In them the charge is arried, consisting of about a thousand ounds of explosive, mounted on _ the crutch-like frames. The firing wires which lead" back to the electric igniting coils are seen in our picture projecting from the rear. The outposts are telephoning the dider to fire. The fatal button is pressed— then: ghastly destruction. ~And the enemy? Has he no defense? No doubt he will erect concrete barriers, and blast huge craters. however, would be a single means of over- coming the craters. The use of percussion caps, which would ignite the torpedo charge on striking the walls, would be one way of smashing through them. Let us not forget that once we can get the torpedoes there, the rest will be easy. If, nothing else can be used, time-fuses will set off the charge at the proper instant. The other military considerations - in- volved in the practical application of the project are much more simple. There will be no difficulty in constructing the light _ type of automobile that would be required. Caterpillar wheels, - In fact, the plan would provide the means of giving many an antiquated automobile which is about ready for the junk heap, its opportunity for making its last sacrifice. From the shipping point in Europe, the men of the ‘‘Land Torpedo Corps” could each ride an automobile directly up to the front, thus relieving the railroads of the burden. Here the torpedo charges could be mounted, tests could be made, and everything could be planned for a con- certed assault. To launch the torpedoes on this drive, competent officers would have to set and lock the steering gears. Throwing open a clutch from the rear of the machine, the automobile leaps ahead audaciously.. The vital parts being armored, the enemy will . be unable to damage it severely when. the machine is seen to be rushing towards them at some sixty miles an hour. Closely resembling this land torpedo is the torpedo car described on page 526 of the April issue of the Popular Science Monthly. It too is designed to take the place of artillery in preparing the way for infantry attack. A torpedo carrying several hundred pounds of high explosive is mount- ed onachassis. The propelling power may be either gas, steam, compressed air or a storage battery or electric motor. Its most important feature concerns the method by which it is guided and fired. This is done by means of cables and wires in the hands of the attacking party, which is a noteworthy advantage over the land torpedo described in this article. Furthermore, the torpedo ‘car, should it not reach the enemy because of rough ground, can be drawn back to the trench from which it was started by a simple pull on the control cable. The torpedo car - would cost about one thousand dollars, whereas the modern naval torpedo costs seven thousand dollars. 323 Popular Science Monthly Salvaging Motor Wrecks with a Special Equipment Car KA JE have long been familiar with the wrecking train of the railroad with its special crew of trained mechanics and its hoists and derricks for clearing away debris or setting cars back on the track again in case of wreck or collision. But it is only recently that the wreckers for the motor world have come into view. One of the best equipped cars of this kind is operated by Mr. Meehl in Port- chester, N. Y. The wrecking carwithitscrew is ready for instant service and answers calls within a radius of one hundred miles at any hour of the day or night. The car itself is a simple chas- sis. On the rear end is .a two-ton hoist and all sorts of rope pulleys and tackle, besides jacks and tools for emergency repairs. A two- wheeled truck is part of the equipment and is used when towing cars whose wheels are out of commission. Two powerful acetylene searchlights are used to light up any night work and two heavy jacks are carried on the running board which are used to jack up the rear ‘take the strain off the tires. The slits in these opaque glasses admit only a small percentage of direct light rays to the eye © Brown and Dawson The wrecking car answers calls within a radius of one hundred miles, night or day wheel when there is any hoisting to do and With this car it is possible to tow in a wrecked car, no matter how badly it may be broken up and it is possible to pull the car out of any kind of a hole. It has frequently had occasion to hoist cars out of streams or up an em- bankment twenty-five or thirty feet high. How the Eskimos Taught Us to Take the. Glare Out of Motion Pictures AVING suffered from the flickering and_ glare of motion pictures, Dr. F. C. A. Richardson, of New York City, developed a pair of opaque eye- glasses with narrow slits in them, through which he views the pictures. without the slightest discomfort. The Eskimos have used similar glasses for years in prevent- ing snow blindness. Whena person looks at a motion picture with the naked eye, he receives the intense rays through a comparatively large area of the eye. Less than one-half of these rays are necessary. The other half simply tax the eye. They add nothing to the clearness of the picture and pro- duce the intense glare. Potash from California Sea Kelp Subterranean reapers harvest the product The kelp is cut four feet below the surface and is carried on deck by belts. Here it is crushed and stored in tanks HE potash | problem has been successfully solved. Our supply of raw material for its manu- facture costs little and is practically inex- haustible. Near San Diego, California, un- dersea reapers are harvesting kelp, from which potash equal to about three times our annual importation from Germany previous to the war, is made by one concern; a second plant of about equal capacity has been established in the same vicinity, and a smaller plant installed by the Government is in operation. Just now, the manufacture of munitions requires all that can be pro- duced, but we can obtain all that is re- quired for ourselves and our allies. The reaper cuts the weed four feet below the water surface when empty and six feet when loaded, the depth having been The harvester waiting for the tide to come in before it . con- tinues its. un- dersea kelp-cut- ting operations made a Government regulation for conserv- ing the supply. Each of the three boats in the Hercules fleet takes about five hun- dred tons every working day, which means practically every day in California. The cut kelp is carried aboard the harvester on a continuous belt elevator to a mill, where it is crushed. The resultant sticky, gelatinous mass, deposited in the storage hopper, contains about eighty per cent water. This is pumped through a six-inch pipe. As soon as a capacity load is ready it is transferred by pumps to barges and thence into digestive tanks on the wharf, each of 50,000 gallons capacity. Subsequent processes deal with evaporation. 325 326 The seats are fast- ened to _ pivoted pipe uprights . At right: The truck carry- ing thirty-eight soldiers Lift Three Floor-Planks and this Motor- ‘Truck Carries Thirty-Eight Soldiers QUIPPED with a new type of body in which three of the floor planks may be raised to form seats, the novel motor-truck shown in the accompanying illustrations is capable of carrying thirty-eight soldiers sitting astride the three seats. By this method of seating, the soldiers are carried much more comfortably than would be the case were they obliged to stand on their feet on long overland journeys. It also permits every available inch of body floor area to be utilized and practically in- creases the seating capacity one hundred per cent over that of ~ the ordinary type of body. The three seats are car- ried on pivoted pipe up- rights which can be locked in a_ vertical position _when the seats are to be used. When -not em- ployed, they can be dropped in three min- utes in such a manner that the top boards of the seats are flush with the other boards of the floor and form a flat platform or stake body which can be used for the transportation of» freight, baggage or other supplies. As shown, the sides of The hook and bait carrier clamped to the rod near the reel Popular Science Monthly the body are slatted and are hinged along their lower edges so that they may be swung down to permit of easy access to the seats from both sides of the truck. The novel body was invented by P. Landes, of Chicago. Except for the body, the motor truck shown is of the conventional type, with no changes necessary for the body mounting. It is considered by experts who are giving their attention to the question of transportation of troops to be a solution of one phase of the problem. ‘The seats are so con- structed as to allow of / equal distribution of the - weight over the wheels. This gives necessary bal- “ance and increases the carry- ing capacity. Carrying Your Hook and Bait Where They Won’t Drag NE of the fisherman’s’ troubles, the snagging of the hook when walking through grass or brush, is eliminated. by. means of a protector which is attached to the pole near the reel. The hook with its bait is placed in the wooden carrier until the fisherman again reaches a place where there is space enough to cast his line with- out getting it entangled in the brush. The minnow or other bait is perfectly protected from mutilation, and catching the hook in the clothing is also avoided. The protector is light, and helps to balance the reel on the pole, which may !be either of steel or wood. The pro- tector is attached se- curely to the pole by a clamp which can be tightened by hand. So far as casting goes, the fisherman may probably be in- convenienced a trifle at first by the additional weight of the carrier, but he will soon become ac- customed to it. The carrier is large enough to accommodate a plentiful supply of bait and hooks © “of “all ‘sizes, even those used for deep-sea and salt-water fishing. bles other cameras in only one 3 ‘Taking Photographs with a Concealed oy Buttonhole Camera NE of the quaintest and J most ingenious detective cameras ever devised has been invented by A. A. Ciani, of East Orange, New Jersey. It resem- feature, the lens, but even .that feature is distinctive, so that it might be said Mr. Ciani’s camera is without a counterpart. It is designed to be worn concealed under the coat, in the manner shown in the illustration. The protruding lens can be placed in the top button- hole of the coat and photo- graphs taken without any- one knowing it, by pulling ‘a string hidden in the pocket. Look carefully at the illustration showing the interior of the camera and you will see the shutter, partly operated, in a sector shape. The shut- ter appears on either side of the lens, in the opening just below the stem. Over the brass centerpiece, but not visible in the photo- graph, are two rubber bands which come into contact with the sensitized plate. By operating a knob on the front side of the camera, the centerpiece is turned and with it the plate. Four photographs can be taken on a plate, as there are only four teeth on the centerpiece. Every time a picture is taken the plate is revolved one- quarter turn. The shutter is operated by Popular Science Monthly The detective camera is worn concealed under the coat. operated by pulling a cord which is led from it into the pocket 327 Inflating Huge ‘‘Pillows’’ as Targets for Airplane Practice _ N the days when balloons were more of a novelty than they are now, gas-bags were often made in the form of animals and human beings. The ‘‘pillows” ‘which are shown in the photograph below may be regarded as a relic of that time; but they are used for a far more practical. purpose than were the old man and animal- shaped balloons. Nowadays, the heaviest naval guns are the only weapons able to decide battles. If there were no airplanes, these guns, too, would be powerless; they could not direct their fire tellingly without aid from a watch- ful man in an airplane. Hence, the fortunes of modern battles rest not only with sixteen-inch guns but in the last analysis with airplanes. That explains the stern struggle which is being waged for supremacy of the air. The ‘pillows’ shown herewith are really balloons roughly shaped like rectangular wings. Fighting in the air requires so much skill in an entirely new sort of marksmanship that the practical British have hit upon the scheme of systematically training their air fighters in shooting from speedy airplanes at these odd-shaped balloons. The balloons are not inflated with gas, as they rest on the floor, but Friction bands for It is pulling the string con- cealed in the pocket. The coat can be but- toned over the camera without in- convenien- cing the wearer and without ex- citing the suspicion of with air from a big electric blower in the center of the room. Such a blower is found in every balloon factory for use in var- nishing; for only a dis- tended bag can be var- the one to be snapped. The balloons are inflated and floated at the end of ropes. British aviators fire down upon them with machine guns nished or in- spected. 328 This Airplane- amoben Takes 750 Exposures with One Loading HE greatest work of the airplane is to locate the enemy’s strongholds and batteries and then map them. The multiple airplane-camera which the Allies are using—an American invention, by the way—can® map ‘the German lines with truly marvelous pro- ficiency. Where, in the ‘first part of the war, artist- observers were used to make pencil sketches as accu- rately and as quick- ly as they could, now. cameras such as this one are em- ployed to take thousands of. pho- tographs at the rate of one a second, if necessary. One multiple airplane- camera alone is capable of seven hundred ‘and fifty: ex- posures with a single loading. The secret of ‘this great capacity lies in its use of ordinary motion picture film.: It is con- structed much like the ordinary film Shutter _ release Shutter timing control. camera, with the exception that the turning: of the film for a new exposure is accom- plished automatically by the action of a set of gears. The camera that takes 750 exposures with one loading Popular Science Monthly The Electric Stevedore. | It Saved $18,000 in Labor Costs in a Year ELOW is pictured an electric floor- truck that does the work of ten man- propelled trucks. The pull- ing effort of the single front power-wheel is such that a | railroad flat car weighing 33,900 pounds is hauled over sandy soil, carrying several interested observers. - The truck is the in- Cam vention of J. E. Haschke, . *ver_ of Los Angeles, the man at the wheel. The truck weighs but — 1500 pounds. The mo- tor is mounted on the yoke of a caster wheel, which permits the truck to. revolve. within its own wheel base; hence its peculiar usefulness upon congested floors. The wheels are rubber- tired. : A striking feature is em- braced in the two levels of the truck, one but twelve inches from the floor. Any level of platform desired or demanded by warehouse needs can be provided. The truck will carry a ton on its back and tow several tons more on trailers; or it will carry several tons of iron, for instance, at a time over good streets. Pivot The camera is placed on the airplane so that it will have an unobstructed view downward and slightly for- ward. One pull on the flexi- ble cable, connected with the operating lever of the gears, winds up the previously ex- posed film, sets the shutter, makes the new exposure, and registers its. number. A spring instantly brings the lever back into normal posi- tion. ready for the next pic- ture. This happens so swift- ly that it is possible to make a continuous record of a flight.. In bomb-dropping the camera is capable of tak- ing pictures of the bomb in the. air and at the very in- t stant of explosion. | It would take ten man-oper- ated hand trucks to do the work of this electric truck Popular Science Monthly 329 [een > Kl Above: The two hundred sound-proof rooms were finished in five days by using a quickly- applied, ready-to-put-up composition board At right: Putting up the sound-proof board material. Standard lengths were used and practically unskilled workmen employed Two Hundred Sound-Proof Rooms and How They Were Built in Record Time ITH only five working days in which to erect two hundred sound-proof rooms in the large Coliseum in Chicago, the management of the National Music Show was confronted with an extraordinary problem. The difficulty was made all the greater by the impossibility of getting a sufficient force of workmen on account of the unusual war demands. The problem was solved by the use of a composition board material which proved highly efficient in deadening sound. In fact, although the walls were very thin, as is shown in the photographs, no sound of the numerous musical instru- ments or of voices penetrated from one room to the next. The rooms also made a very handsome appearance. The auditorium built for concerts By removing the thumb suddenly from the trigger the disk is shot up into the air or out, as desired had much the appearance of a real audi- torium built to stay. The rapid construction work was made possible by the lightness of the material, and the fact that comparatively unskilled workers could put it in place. A Paper-Disk Flipper for the Youthful ‘‘Cut-Up,’ IRLS and boys alike derive endless amusement from a new device which throws a paper disk larger than a silver dollar from a hundred to a hundred and fifty feet into the air. The device is very simple in its opera- tion, but flips the disks to a surprising height. You simply hold it in your right hand, with the thumb on the trigger member in the position shown in the illustration, then remove the thumb suddenly, and up or out the disk shoots. In the Grottoes Under the Battlefields While the battle line sways back and forth over Verdun, in France, the military authorities live underground and carry on their business as usual At left: The composing room and press of “L’Echo de Paris.” Underground France must have its daily newspapers French Official Photos Wl types “hes Ss Class Lenina y WOT ST From this subterranean office all permits are issued for travel on the city streets In spite of their cellar quarters strict records of all affairs are kept by the city officials 330 -'The Trench Farms of the Philippines Notwithstanding the fact that rice grows best in valleys where the soil is rich and where it is kept flooded almost continuously until the grain matures, the Filipinos, who are as dependent upon rice as are the Japanese and Chinese, have succeeded in growing it upon mountainsides. There is of course a variety called ‘‘upland rice,” which requires less water than that grown in the valleys, but even this is grown in marshy soil, kept wet by a trench system which holds back the rain and the irrigating streams preventing the water from flowing down the mountain and holding it in grooves in which the rice is planted. Huge water buffaloes are used to drag the plows and harrows through the mud. Sometimes these animals are blindfolded and made to turn wheels which elevate the water from the streams to the trench-fields. After the rice sprouts are set out, the water must be let off from time to time to permit weeding and cultivation, but it never destroys the ledges AEA ANSE FLD -@ Brown and Dawson * Remote from Man the Eagle Builds—But Alas! Wh 0 ee 3 Oe Gr.” spe age : 7 ZY i : rs gS Ss A pair of young eagles, two months old, in captivity. They have just been cap- tured from a nest on @ distant mountain. Note. the wild look in their eyes. This is never entirely lost vi SG i” —v org 55 Gi 6° € 73600 5 *ZEFEZxWrrXxszwqwW 9° !™&" SSS pus Cg % Bi ti mers Cor oP Ss WLLL lddddddddllida lide — WOMAN SSS SMS MAA PES: ee : i ee all aE UZ AM needed dda WS Risking his life to reach a nest. In Santa Clara Valley, California, searching parties capture the birds and despoil their nests - SSG E M98 Bringing a young one to earth from its aerial roost. When two months old, eagles are ungainly creatures. They have not sufficient strength to use their wings and hence are helpless SSS At right: A searching party and mo- tion picture operator ‘réturning to earth after a successful hunt. In addition to the danger of breaking their necks the hunters face the risk of being attacked by the mother bird SSS AWWW FTFt | rpm 332 Bungalows on the Roof of a Post-Office The post-office occupies the ground floor, and the bungalows take up the space that would otherwise be the second floor. The nine bungalows rent for $25 a month each The bungalow residents have the advantage of being down- town and at the same time of living in an at- - mosphere far re- moved from that of an ordinary apartment house Above: The top of the post- office bungalow colony. The windows seen on the second floor as one looks at the building from the street are the windows of the bungalows 333 And the Inventors Never Cracked a Smile One of the fountain pens above was in- vented in 1847. The ink was contained in the bulb section and sent down to the point by pres- sure on the piston rod. Note the two- pointed pen and the pen with leather finger loops Patented ’way back in °57, for floating horses across streams. Four bladders, inflated with air, are strap- ped to the horse to buoy him up Even musical instru- ments have not proved Here we have a violin-horn, a two-stringed affair, and a gourd-like man- doline which resem- bles an Indian club 334 Rockers more than ordinarily The one at left above is a veritable rocking horse. The other has an additional rocker to prevent it from rocking . The chair below isa life - saving device’ made of zinc. When the ship sinks you float off into the water still seated and enjoying your paper and cigar To get those highboots of 761 | off, bootjacks were used. . The chair has a kind. of oarlock for ‘this purpose and the shoe has a> brass projection ' which slips back into a groove in the leather heel when not in use ‘France’s Tank Contribution to the War Photos ©) Underwood and Underwood 333 The tank all France is talking about. It is fitted with heavier guns than the British tanks, but it has not made any par- ticular name for itself in the fighting so far. The usual type of caterpillar drive is used Major Bossut and Lieut. Boucheron and the new tank. The photograph was taken just be- fore the tank brolze down inside the German lines. Rather than see it fall in enemy hands Major Bossut blew up the tank killing himself They Earn Their Living Simply by Seeing, The perfume smeller tests the most deli- cate aromas with his critical nose and places a value upon them. It is interesting work, provided the perfumes are good Contrary to expectation tobacco is sampled by +he sense of touch. If the leaf does not feel right to the sensitive finger-tips of the expert it is rejected / The coffee taster is a half brother i - in trade to the tea taster. He ‘ never drinks coffee; he tastes it. His beverage is made a sip at a time in a porcelain coffee pot on the French drip method 336 Hearing, Smelling, Tasting and Feeling ears oeaae eooeeeeee cecoeoscoesooem™ Oma OOO geneooeoooeses® : enoere 26E6 2900608 ccoeeeRESUUUSTTe eC 5b SHOSSOSSSOS WOSTS Be 66 & eeeer S6O68 OO FO Ce0ee Om <4" The motion-picture director holds his job on the strength of his eyes plus his imagina- tion. Every time he examines a film visually he imagines himself to be a hundred thou- sand picture fans all in one With ears trained to detect errors, some men are expert she sis ae oth listeners, Singers as well known as Caruso are some- 9 ia cam tm ooh STC het he I Me RR ee oe ese ce times obliged to abide by the verdict of a listening jury, ae 2 ae ae such as the one shown above we eet a eae tS ae ; SAR ce ey tt ag Tea tasters are employed by every first-class tea concern and by the customs officers of all the Governments. Some of the tea experts chew the leaf, some judge by smell and some sip the beverage Cats? Demons? No; Just Chunks of Wood The curio shop of Moses Ogden, of Angelica, New York, with some of the finished curios in view and a pile of promising ma- terial at the side of the house. In his tramps through the woods Mr. Ogden discovers all sorts of queer faces and figures peering out from brush and branches of trees Some of the curious images appear just as Mr. Ogden found them in the woods. Others suggestive Li The combination figure at the left is suggestive of a poultry yard. In the center is a snake on the lookout for eggs. Where the ordinary person sees only a knot of wood Mr, Ogden sees a queer-look- ing dog with an owl’s head, or a gnome true to story-book description, or. something else uncanny of the hapless creatures that Dante’saw in the Inferno have been shaped with the penknife, There are no particular names for these dignitaries and no special uses except as “‘ornaments 338 There Is Pleasure as Well as Profit in Skunks. Your Next Year’s Fur Coat May Come from a Farm Like This Photos © by Brown and Dawsop Above: Skunks make admirable pets when they are young. They are as playful and as harmless as kittens. Only the older ones need to be handled with care The striped skunk is the only one that makes money for the breeder. In return for good care and feeding its fur becomes ex- ceptionally thick and glossy The skunks are given as much freedom as possible in wire pens. They are great diggers, consequently they have to be watched continually and the pen walls constantly renewed 339 \\ Streamline \ \ ss Dingle wide 4 , Struts set angularly bes J Housing for because lower 7, Gnome motor wingis staqgered bck ce, : The latest Nieuport ‘‘Avion de Chasse,” or fighter, mounts three machine guns. Two on top of the plane fire over the propeller and one beneath the upper plane fires through the propeller. The perfect streamline body, the small wings and rudders and the big propeller with a hood in front enable the machine to travel at 120 miles an hour - Machine gun showing how violent slipst of Exhaust ‘manifold Machine gun firing over propelier, Magaz ines Machine gur uit “e- French Official Photos The new fast armored Farman fighting plane. Only one ma- chine-gun can be carried because of the armor’s weight. Another view of this machine appears * A o at the top of the next page. Ne tubp4e A Pk The armor over the cylinder le Vbaane une : heads of the engine is perforated os so that cooling drafts may enter, the strong slipstream from the propeller entering through the circular opening in front, passing through the radiator and finally emerging through these holes g ‘ - Lacing for = age covering ae The three machine guns of the ‘“‘Avion de Chasse” are aimed by pointing the whole machine straight at the enemy. They are fired simultaneously by the single pilot. Ordinary machine guns are used, evidenced by the useless rear handles and pistol grips BAN Armor Appears on the Airplane On this and the preceding page we present pictures of the newest French airplanes— an unarmored fast fighting Nieuport “Avion de Chasse,” a fast armored Farman biplane, and a heavy weight-carrying Caudron, all of which are in active service &: x oy; . : ay Armor perforated” to ventilate engine Aa . i 4 a Armor “PMachine on) . Exiiaust tube to conduc& gases away gfrom pilot... French Officiai Pnotos In the new armored Farman biplane the exhaust is carried far behind the pilot through a perforated tube. A certain amount of muffling is also thus attained. The machine gun is obviously cooled by forced draft produced by the violent slipstream of the front propeller. The armor leaves much of the really vital portions of the machinery necessarily exposed, such as part of the radiator; still it increases safety gp Machine gun Se SA : 7 es Tubular framing supporting pivotof gun Propeller % * : q Massive flaming ’ running to wheel- to support tail ok necessary inheavy machines Either one of the pilots of the two-motored Caudron may stand up in turn and fire the machine-gun, the man in front rearwards, and the man behind either ahead or abeam 341 Below: Sewing the sweat band on a finished hat. A machine does the sewing in one-half the time required by hand operators Photos @ Brown and Dawson rq The first process in making an army hat is shown above. The metal shaping cone is placed over the fur and revolv- ed at great speed At right: Making the crown and brim smooth by putting the hat through a series of grinding rollers cov- ered with fine emery The inspection ta- ble. After the hats are shrunk and dyed they are ex- amined before be- ing sent on to the forming room Below: The cone of fur as it is re- moved from the blowing machine, It is very soft and delicate requiring careful handling Above: The brim- ming machine which stretches the edge of the hat until it resembles a brim. Shellac gives the stiffening _ Processes Through Which It Passed in the Making Two stages in the molding of a hat are shown below. In the man’s left hand is a hat which has just come from the pressing mold. The hat in his right hand is the “before pressing’? model At left: Five ounces of raw fur are used for each hat. The scales weigh to within one six hun- dredth of an ounce. Most of the weigh- ing is done by automatically operated machinery Photos © Brown and Dawson Above: Cutting the brim of the hat toa uniform width. As the work is done by machine there is no chance for error Forming the hat i g the hat in The hats are dipped a steam-heated press. A steel die in the lower part of the mold gives the finished hat its size and desired shape in shellac, then passed upward through rollers which wring out the surplus liquid Wood Carving by Machinery—A Novice Can Do It sai AE a © Brown ahd Dawson Formerly when an elaborate carving had to be duplicat- ed many times, each _ duplication had to be worked out separately. To-day the dupli- cations are made five at a time The original carv- ing shown here was made in plaster of Paris. The repro- ductions in wood were made by a machine which con- sists of a battery of four rotating drills and a_ stationary rod which the ope- rator moves over the outline of the pattern. Every movement of the master rod is dupli- cated by the four repeating drills When a very large number of repro- ductions are to be made of a certain design, the original is generally made in wood. With this machine one novice can do the work of five skilled men | 344 . 1 New Fashions in Gas Masks ated, sy arp nonin a aR ON neue The mask which is in use at ; Impervious to smoke and flame, the present time by the English the mask is made of asbestos and the French. To the sol- Worn for gases which are and is worn by rescue squads in dier in the trenches the gas poisonous but which do fires and explosions. An entire mask is as important as his rifle not affect the eyes. The suit of asbestos accompanies it mouth and nose are pneu- matically sealed by a rubber-faced cushion Below: Afhelmet built especially for workers in tobacco plants. Heavy irritat- ing dust is thus prevent- ed from reach- ing the lungs Mask used by our submarine sailors when salt water reaches the electric stczage batteries and chlorine gas is generated in consequence Worn for protection against chlorine gas by workmen who are constantly exposed to the gas in chlorinating~ plants Like a dentist he removes all de- cayed matter from a_ cavity HE science of tree surgery is but twenty years old. Yet it has already become of inestimable value. It is - saving thousands of shade trees and fruit trees each year. All trees, and sweet- sapped trees especially, are liable to fungus disease. The fungus is a parasite by nature and sends Operating Upon Trees When trees get sick or are dam- aged they need the tree surgeon Photos © Brown and Dawson the weakened trunk would not be undul: strained under the action of the wind. This was a comparatively easy task, but real tree surgery is not simple. It is a diffi- cult and exacting art. Some trees require a combination of bolts and lock-nuts, rein- forcing rods-and cross-bolts with lock-nuts above the crotch. Others need a combinc- tion of bolts and criss-cross bolts with lock nuts, tortion rods and: chains, and still others call for iron straps, tortion rods, iron backbone and ribs in addition to chains and lag-hooks higher up. Another illustration shows large cement fillings built up in separate block sections to allow swaying of the tree. Ina very short time, the edges of the cut “heal” to the cement. That is, the soft living tissue solidifies upon the cement, making a tight joint which is waterproof. Often the bark at the sides of the patch gradually grows to- gether closing little, thread-like tentacles into the woody tissue. These travel from cell to cell, disintegrating the internal structure of the tree. The result is what we call vot." When fungus starts in a tree it never stops unless ar- rested by human skill. The tree surgeon alone can destroy the disease. The accom- panying illustra- tions show how useful tree sur- gery can be. In one of the itlus- trations is shown steel cables strung between over the cement. Young trees are not so difficult to doctor. One of their chief ene- mies is the bore worm. The tree surgeon, upon discovering a worm hole in the tree drills into it with a stiff wire, kills the worm and fills up the hole with tar. But tree sur- gery isnot merely a matter of filling cavities. Unless the work is scier- tifically accurate and mechanical- ly perfect, it fails. Since decay de- stroys the struc- tural strength of the tree, this strength must be the upper branches so that A sick tree on the way to health. filling reaches almost to the heart of the tree restored by me- The cement s chanical means. 346 Tree Surgeons at Work gree aoe Above: In filling a cavity the cement is laid in sections. This prevents + the cracking or breaking of the filler when the tree sways in the wind Above: Healing soon takes place and the cambium (new growth of bark) rolls gradually over the cement filler, sometimes com- pletely concealing the patch Left: A tree whose trunk split asunder. The doctor has inserted eyebolts and has drawn the branches together again by means of wire cables 348 Popular Science Monthly Change Your Coal Stove Into a Gas Range HEREVER kerosene oil is to be had, it is possible to convert your coal stove quickly into the decidedly more convenient gas range. A new attachment put on the market for this purpose is sufficiently simple for the least initiated to operate. A kerosene tank is screwed to the wall and the clamps on the burners are at- tached in the stove’s fire box. From then on you will forever be free of the bother of both the coal bucket and its col- The food barrows of London serving meals ready prepared and hot or cold to patrons of the community kitchen A Kitchen on Wheels—the School Children Serve the Meals N St. John’s Wood, London, the com- i munity service idea has been worked out to a nicety in relation to the kitchen and the serving of meals. Not only are housewives and others relieved of the duty of cooking the meals, but school children of the locality are pressed into service as cooks and waiters. Every day the food is sent out from the community kitchen in what are called food barrows. ‘These are wheeled through the streets and are stopped upon demand at the doors of prospective customers or old pa-; trons. The food is carried in big alum- inum pots and ves- sels which fit into a metal container filled with water which may be boiling hot or “ice-cold, ac- cording to whether the food is to be served hot or cold. Soup, coffee, and vege- tables of all kinds, meats and desserts are served in any desired amounts, in individual portions, or enough for an _ entire family repast. The kerosene passes drop by drop into the pipes over the flames league, the ash pan! The attachment is in reality a miniature gas plant. After fill- ing the tank with kerosene oil, the valve is opened until the oil begins to trickle from the burners. The valve is then closed and -the little oil previously placed in the iron pan under the -burners is lighted. The heat from the burning of this oil causes that in the pipes above it to evaporate. As soon as this happens, the gas issues from the burners and it is ignited also. The intensely hot flames then given out can be directed on to whatever parts of the stove they are needed. Having once started the evaporation of the pipe oil, the tank valve can- be again opened. What- ever oil thereafter flows from the tank will evap- orate in the red-hot pipes over the burners and be converted - into gas. One drop of oil will produce an immense amount of gas; obviously, then, the tank will be exhausted very slowly. The fact is that not more than two cents’ worth of oil need be used up in an hour, according to -the inventor, who also. emphatically de- clares that there is posi- tively no element of danger in. the device. ‘fA little child can man- age it,” he says. “she Popular Science Monthly Did You Hit the Target? This Target Answers £ \NE of the objections to rifle shooting XJ from the standpoint of the spectator is that you can’t see what is going on—the results of the shot, as you can when you watch shotgun shooters smash clay 349 does so, and again lighting the front lights. When the bullet passes through the card- board target in the holder, it continues on down the funnel, striking the steel plate and driving it and its arm into the air. The bullet then continues into a curved bullet- stopper of heavy steel Stopto break impact and comes to birds. To make the game more inter- — Dash pot or _- bullet Teh sion rest. esting to the spectator and to mark the = “"/*“**t ie Instant- target for the shooter without Air valve Greuther ly, by the the necessity for walking out bili :; A §=action of mse let deflected ze and retrieving the target or againt steel plate WOR. Getlector. | the arm hauling it in on its carrier, Back stopto 4 driven vi- _Frank C. Reed, of Springfield, “*” bullet > olently _ Ohio, has designed and put on upward by _the market what he terms the the bullet, “spot shot”’ target. He takes the front advantage of the fact lights are that if you ex- put out tinguish all front anda lighting on strong a paper and D - nae from ron t a —— b = At left: A circle of light shows Spree 5 Saat the bullet hole. Above: The 5 hind it, any details of the lighting device target hole. ' perforation will show _ plainly in _.silhouette. _ Inastrong iron box he puts front lights of suitable strength and arrangement to best light up the small cardboard indoor minia- ture rifle target, and protects these as usual by a steel plate. Behind the target, which slides into grooves formed in the box, is a funnel- shaped passage leading back from the target to a movable plate at the end of an arm that con- ; Washing for Gold in the Clayey Soil of the Guianas N working for gold in the Guianas, where sluices are impossible because the soil is clayey, the ground is worked with a ‘‘Long Tom,’ a puddling-box about eight feet long. The tom is filled with the gold- containing mass by a spade-man and a hoe- man. The larger stones collect against the perforated iron plate at the end of the box fitted with trols a circuit breakerfor‘h: . light circuit and for the normally ex- tinguished light behind the target. This arm also operates a dash-pot or air-jacket that slowly draws the arm and its plate down to place again, breaking the rifles through which the dirt- bearing water flows. The worker throws the stones high in the air, watching fora glitter of gold. To make sure, he catches them again and perhaps repeats the trick, which seems simple but really de- circuit for the backlight as it Before dropping it into the ‘‘Long Tom’ the washers toss the sand high in the air to catch the glitter of the gold mands the highest skill. 350 © Int. Film Serv. The latest fashion in helmets — the screen-like visor which protects the eyes. It can be raised and lowered A Screen Visor Is Added to the French Helmet of Steel REVERSION to primitive methods has been one of the remarkable fea- tures of this war. In our school days we learned that soldiers gave up the use of armor because they could fight better without it, and because it afforded no ade- quate. protection after firearms became available. Now we must change our minds all over again, for trench helmets of steel are considered absolutely indispensable and even chain armor is used. The French were perhaps the first of the warring nations to actually equip their men with bullet-proof headgear, and they are the first to attach a screen-like visor of steel to the helmet for the protection of the . eyes, as the photographs above show. The visor can be raised and lowered and when in the latter position it af- fords the eyes protection against shrap- nel and shell splinters. Judging by the size of the-perforations, the visor would hinder rather than assist the soldier. when he is required to take accurate aim in firing. Popular Science Monthly Creating a Vacuum to Induce Artificial Respiration A NEW type of resuscitating device which commands attention because of its novelty if for nothing else, has been in- vented by H. E. Acklen, of Memphis, Tenn. A rubber cup which creates a vacuum when operated after the fashion of a pump is the inventor’s method of methodically raising and lowering the patient’s diaphragm to induce breathing. Whether the rubber cup is strong enough to raise the chest and lower it, is the question upon which the practicability of the apparatus rests. At first thought it would seem as if the cup would have all it could do to raise the leather pad and the skin, to say nothing about the chest. But if there is a question regarding the raising capabili- ties of the device, there is no question but what it is suffi- ciently strong to depress the chest. The handle enables the operator to exert a considerable pressure on the in- strument. The vacuum device is secured against the chest by straps which are held to the floor under the operator’s feet, as the illustration shows. The up and down movement of the device may be regulated by the straps under the feet of the operator. They also hold the patient down. If the apparatus proves practicable it will _ doubtless be the quickest method yet devised for resuscitating the all-but-drowned. The pressure on the abdominal walls will force the water out of the stomach. Raising and lowering the chest with the rubber cup the deposit of U.washed Sponges Are Fifty Per Cent Dirt ANUFACTURERS who use_ large quantities of sponges have found that in buying them at a fixed rate per pound, they were paying too much for plain earth. They now require every carload of sponges to be analyzed. Samples are taken from each car and weighed. They are then put through a standard washing process and weighed again. Fifty per cent impurities _have been found in many cases. Using Live Steam or Vapor to Save Gasoline “HE device shown below is designed to reduce the consumption of gasoline by introducing live steam or vapor into the intake manifold of an automobile engine, especially on-those carburetors which are difficult to adjust properly. The apparatus consists of a small cylindrical chamber screwed into the exhaust manifold, which contains a rotary valve controlled by a cable from the driver’s seat. Hot exhaust gas is introduced into the chamber through a port in the rotary valve, where it meets a small amount of water drawn through a pipe tapped into the water-circulating sys- tem. Meeting the hot gas, the water is turned into steam and thence fed to the in- take manifold through another pipe where it mixes with the fuel from the carburetor to form a more economical mixture. The amount of wa- ter entering the rotary valve is con- trolled by a small needle valve at the top. Besides pro- ducing a more economical mixture, the presence of a small.amount of ‘water vapor in the cylinders tends to soften intake manifold carbon and Popular sates M —— sea water circulation pipe agg The evaporation-cooled refrigerator is the Cali- fornian’s answer to the desert’s blistering heat ThelImperial Valley Is Off the Ice-Man’s Route: Hence the Burlap Cooler OU can fry an egg on a rock in the Imperial Valley of California by letting the sun do the cooking, but a Rockefeller couldn’t afford the price of a tumbler of cracked ice. But this does not mean that the Californians have to do without food refrigerators and various cooling devices. J. G. Hill, of Mecca, near the Salton Sea, has contrived an evapora- tion-cooled re- frigerator » Bf exhaust a N which requires Moist air to /¥ 2 no ice. intake Pt has: 2 iD: 4 wooden frame- work, and in- cludes numer- ous shelves. Several layers of burlap cover it. A perfo- rated tin can at the top is connected with hose which sprinkles water over the entire burlap surface. retard addi- tional forma- tion. The principle of the gas-saver involves moist air heated from exhaust gases and introduced into the manifold The evapora- tion keeps the interior cool. 352 Surveyors climbing to the top of a precipi- tous cliff in Alaska to take observations Risking Lives for the Sake of Pre- cision in Government Surveys NE of the most difficult and exacting tasks of an extensive land ° survey made by the United States Coast and Geodetic Survey, is the selection of points from which observations may be taken. In heavily wooded country it is necessary to climb the tallest trees or to raise poles taller than the trees, from which the distant horizon can be seen and such observations made. as may be practicable. In mountainous country such as Alaska, the surveyors have to face death for the sake of precision, g climbing the highest peaks in order to obtain an unob- structed view of the hori- zon, Why risk one’s neck to make a simple survey? Because when great pre- cision ‘is desired it is im- possible” with “chain or tape to survey a region in which there are bays, rivers, mountains and other natural. obstruc- a base line. The cardboard cover keeps the school desks always presentable Popular Science Monthly tions. To overcome these difficulties the method called ‘‘triangulation”’ is employed. It rests upon the simple proposition taught in every school that if one side and the angles of a triangle are known the remain- ing sides can be computed. It is to obtain the first side of a triangle, or base line, that the surveyors climb the highest trees and mountains. So painstaking is their work that in a survey of one hundred miles the error is often less than five feet. - The accompanying photograph shows a Government surveying engineer climbing a steep cliff in Alaska, prior to establishing On his back he’ carries the necessary surveying instruments. - “On the top of the cliff stands a companion engineer who undoubtedly scaled the cliff without assistance. The feat is made safér‘for the second man because of the rope which has been lowered to-guide him in -his ascent of the nearly perpendicular. surface. > : If he is to measure a great distance from — the top of the cliff the only.instruments the engineer will use will be heliotropes (not helioscopes) by day and powerful lights by night. The heliotrope is a small mirror so arranged that it reflects the sunlight in a long line toward the observer. Keeping School Desks Presentable with Cardboard Covers JANITOR of a school in : Pasadena, Cal., has found a way to keep the desks in his classrooms looking bright and presentable without subjecting them to frequent planing and var- nishing. He slips over the desk tops a pressed-card- board cover, which he calls an envelope. The enve- lopes are made to conform with the general shape of the desk tops, and the outer edges are bent down and back and riveted, so ' that the cover will slip on over the desk top and will remain in position after it has been adjusted. There is ‘a groove in- dented at the top of the cover to receive pencils and pens, and a circular open- ing is provided through which the inkwell shows. Bea The More Fruit You Eat the Less Water You Need Drink OST fruits contain from 75 to 95 per cent water, and a balance of woody fiber, or cellulose,. fruit sugar and minerals. Thus the free use of fruit daily, insures a greater supply of water to the body. The cellulose of the fruit supplies bulk and a mechanical stimulation which pro- motes waste elimination. Acid fruits, such as oranges, lemons, limes, and most ber- ries, contain a certain chemical compound called ‘‘vitamines,”’ in a very stable form. These vitamines are believed to purify the blood and to prevent scurvy and various skin diseases. Do Your Telephoning While Riding On a Trolley-Car HAT an advantage to be able to telephone from a moving train! Sup- pose you want to warn your wife that you are bringing a friend home to dinner. How easy, if you could take down a receiver in the trolley-car and break the news to her while you are yet afar off. Or, maybe you are a detective and have spotted a long-sought crim- inal. A telephone would enable you to communicate with headquarters at once. At any rate, L. Zsitovs- zky of Philadelphia, has shown that this can be done by inventing an ap- paratus attachable to an ordinary trolley-car. In Popular Science Monthly 353 The lock fits over the porcelain terminal that extends from the magneto case A Lock Which Makes the Ford Car Thief Proof thieves are constantly steal- ing Fords. There are plenty to select from and they are easy to dispose of. The lock illustrated bids fair to ‘reduce to a marked extent the get-aways. It shuts off the ignition at its source. The design and location of the Ford magneto lends itself readily to the posi- tioning of thé device. The lower end of the cartridge fits over the porcelain ter- minal that extends from the magneto case, while the addition to the _ regular top of the lock extends feed wire above are two other parallel wires for the transmission of messages. Contact is effected by small trolleys similar to the large trolley. The two wheels are mounted on arms con- necting with a split collar, attached to the end of a metal pole on the top of the car. The wires pass down through the pole and enter the telephone instruments in the ordinary way. .They through a hole in the floor of the car which places the device conveniently under the coil box on the dash. By pressing the small lever down with the foot, the engine is shut off and the ignition system locked. A special serial key is re- quired to unlock and place the system in operation. When locked it is impossi- ble to make a new connec- tion with the magneto, since forcing the lock from are arranged below the feed wire as a means of protection. The train - telephone. telephone wire is arranged below the trolley feed wire its support will destroy the connections and render the magneto inactives The OLICE statistics show that .. The bottles contain inks of different-colors. Each pen acts as a guard for its bottle Using a Dozen Different Inks With- out Making a Mistake ECHANICAL draftsmen, architects and map makers often use as many as ten inks of different colors in making a complicated drawing. Sometimes it hap- pens that the engrossed artist thrusts his pen into the wrong bottle of ink and draws a blue instead of a red line. Then follows an effort to erase the wrong line, with consequent loss of time. Frank B. Gilbreth, the well-known effi- ciency engineer, overcomes this difficulty very simply and ef- fectively. He has devised a special stand, to hold both the ink bottles and their pens. As the accom- panying photograph shows, each pen is thrust vertically into a hole directly in front of its bottle. The pens thus con- - stitute a barrier in front of the bottles. When a green line is to be drawn, the draftsman picks up the proper pen and thus clears the way for the green-ink bot- tle; only that bot- tle and no other can be reached. It is impossible to thrust © the pen into the red-ink bottle, be- cause that is guarded by its pen. Recruits at the Newport Training Sta- tion in their life-preserver mattresses Popular Science Monthly Don’t Drench a Plant: Drop by Drop UCIEN !DANIEL, a French botanist, » has discovered that young hothouse plants and slips of vegetables, as well as flowers, thrive far better by a system of continuous watering than by drenching the soil at stated periods. The new method depends upon the law of capillary attrac- tion. Near each plant is placed a jar con- taining water, into which is dipped one end of a strip of linen or cotton, whose other end lies near the plant. With this uninterrupted supply of water, drop by drop, the plants thrived, greatly outdistan- cing other plants, which were submitted to an intermittent drenching. The Sailors and Marines Sleep On Their Life-Preservers | T MUST afford considerable consolation to the Navy recruit to realize that the mattress on which he sleeps so comfortabl at night will stand him in good stead in case of an accident to the ship. In fact the very buoyancy which makes it such a comfortable bed is also the quality which makes it possible for it to be converted at a moment’s notice into a life- preserver. The mattresses are stuffed with kapok, a light- er-than-cork material which is imported from the West Indies in bales similar to bales of cot- ton. It is made from the seeds and silk of a tree not unlike the cotton-wood tree, but instead of being in puffy balls, the kapok is in slender threads, which when compressed make a mass _ that is six times more buoyant than cork. Thin layers of the kapok are enclosed in strong ticking for the mattresses. Each mat- tress is provided with tapes long enough to tie around the body and over the shoulders, as shown in the illustration. It requires only a minute to adjust them. > Hurling Barbed Wire at the Enemy A projectile is used from which barbed wire is uncoiled after it is shot at the onrushing troops When the projectile explodes, the caps containing the barbed wire shoot out like bullets in all directions distributing the wire in great tangled masses AFTER a murderous ar- tillery fire has swept away ~™ the ordinary barbed wire entanglements in front of a trench, there is nothing to impede the onrush of troops except machine-gun and infantry fire, accom- panied, at certain times, by well-placed barrage fire from the rear. Under most conditions this re- sistance is sufficient to deplete the ranks of an in- vading force but the fact that the first, second and third line of trenches may be captured in a single charge is proof that gun fire alone cannot dissipate a body of troops. There have been numerous occasions in this war where troops of both sides have deliberately plunged through a heavy barrage fire to carry a line of trenches. Explosive ‘Jime tuse Four hollow caps con- tain the barbed wire coils Accordingly, Enid S. Wales, of Detroit, | Michigan, has invented a novel projectile which shoots barbed wire instead of bullets. 3 His idea is to first impede the progress of an onrushing body of troops by spreading coils of barbed wire in front of them and then to attack them with infantry and machine-gun fire. The in- ventor claims that his projectilewilldistribute masses of barbed wire over a large area, en- meshing a whole com- pany of troops. Briefly, the projec- tile consists of a stem which fits the barrel of a trench mortar; a central chamber con- taining the explosive charge, into which chamber the stem fits; and several hollow caps which carry the coils of barbed wire, the inner ends of which are secured to the body of the shell. When the projectile explodes, the caps containing the barbed wire shoot out like bullets, distributing the wire in tangled masses. A time fuse is pro- vided so that the distance can be gaged. Barbed wire a 979) Feats That an Automobile Can Perform and Ri «We >, ae wy Mla a) nett The automobile as an acrobat. This ‘“‘stunt” was pulled off when the heavily loaded truck slid back but didn’t dump. Once the front of the chassis was started up- ward, it turned around on its ball-bearing pivot Sa ete! bridges) In replacing a piston-ring; bridges of tin will enable you to pass the groove | The pivoted headlight is a welcome innova- tion in shooting trouble at night. The intense, direct rays will light up the rear, and the reflected rays the front of your automobile Qg Wo Bio" I WW 5 Z FY Ya Z Vlllllldldldl Talk about the mud the war-tanks go through! This truck wades hub-deep across a swamp in filling it up No more crawling under the car to raise it! This type of jack makes that unnecessary < 356 Four- ghested drive en- ables truck and trailer to get sufficient trac- tion even on plowed ground. Its use in carrying products di- rect from the farm is important in war A neat aa Saavenient valine and wrap- case to carry on your next automobile trip Q@ 9 gare OO a0 Four differently colored pie-like sections make your speedometer-dial easy to read WO p “a X The little flashlight has nothing on this method of lighting your engine. When the pivoted- searchlight principle is applied to your spot- light, it is easy to locate trouble This bumper will not only protect the car, but will cushion a blow as well. The two flat, Y-shaped springs per- mit a three-inch yield in case of a collision. Bent bumpers will be- come less common Bumper plate Steel bar Pivot plate Your automobile will not be scratched if the garage door is locked by this simple holder 847 “You Made Me What I Am Today” There are numbers of patents that have made money and lost more in the automobile game, not counting all the accessories for ruining a man’s pocketbook, such as spotlights, roller cur- tains, mud scrapers, dust suckers, tack pullers and perfume bottles. The Tillinghast patents covered single-tube tires, and Theodore Dodge made money before that tire blew out; Dunlop made money; the Grant patent for solid tires reaped a fortune and Harry F. Baker is riding in ease on Kardo patents for ball bear-| ings. But it is William Barber of Brooklyn who smiles at us above, over his valve cages used by valve-in- head cars and motor- cycles. Great auto- mobile companies pay him royalties Since all great men are linked with their enemies, George B. Selden ought not to object to our mention of him in the same breath with Henry Ford. Back in 1879, Selden quietly took out a basic patent on the modern automobile. The document dealt with a gas engine, using a clutch and transmission to drive the wheels of a vehicle, and it caused more battles than the Indians ever fought. The first great cases were won by Selden. Ford with the aid of Briscoe won the second batch. The patents were eventually declared invalid. Over eighty manufacturers paid a total of $2,000,000 in royalties under the Selden patents.” Look in any old magazine and see their names in advertisements You will look a long way through Who’s Who in America without finding these names, but it is an oversight that Leonard Huntress Dyer is not in there. Most of these lights of the automobile game were just crazy inventors —according to their neighbors— but Dyer is a well-known lawyer of Chicago and New York. The papers in his case—we ought to call them limousine papers be- cause they all led to closed car opulence—had to do with a series of gears which employed a direct drive in one line with the clutch engine and driving wheels. Fortunately Dyer knew some- thing about the courts. So he fought only a short distance down the ages and then sold the rights to an association of manufacturers of automobiles Oscar Hedstrom,. who is older now than when he posed for the picture at left, showing him with his first motorcycle, was a bicycle rider in the old days before gasoline did the work. He risked his neck before Glen Curtiss made his famous speed record in Florida. He wanted a way to pace a rider without wearing out the legs of two or three men; so he put a gas engine on the bicycle and patented the idea. He has never recovered since, because the royalties have been coming in a golden stream and because he came to be regarded as such a valuable motorcycle engineer that he was given a contract with one of the biggest of the manufacturers in the business “a bi, They Sing of the Automobile and Motor-Truck Mosler’ (bclow), ~went Seeing him sitting here fj : I at the right so peace- fully, you would not picture Ray Harroun in goggles°on a Van- derbilt racer; but that was -where. he got his start. There was nothing in the world so natural to a racing driver as something to smooth bumps and to act as a cushion when you hit a competitor going only a hundred miles’ an hour when you are doing a hun- dred and twenty. The idea came to him when he was fiddling with two little steel springs and watching them in- teracting on each other. It’s a bumper that lifted him from the realms of the cir- . cular track to an office desk at so many thou-~ sands per week that we blush to speak of it The story of L. H. Pecienan and his demount- | able rims (regular equipment—no extra” charge) would be meat for a short-story writer. The picture shows him looking over the wheel that rolled him through the patent office and the courts; but the check for three million dollars which was the first payment made the Perlman Rim Corporation is framed in another room. Perlman was first a printer and then a tinkerer with automobiles and tires, and he did hate to put on new ones! He put together a wedge and a screw and secured patents on the combination At left: You see this man’s work (Edward Hartford) on the back of every high priced car and even on the front. His papers—the same ones which put him on this page—are his because he applied the shock- absorber to the automobile and made even delicate débutantes will- ing to ride in broughams. He pro- ceeded with caution by first buying the Truffault patents which had to do with bicycles and then applying them to the automobile, and then taking out more patents. But even then he had to fight his way through the courts to establish his claims. You see by the picture that he can afford a nice watch chain 359 into partnership with an inventor from Man- istee, Michigan, before he had much use for the initials A. R., which he now always — uses. The patent (the Can- field patent) concerned a spark plug with an air-gap between. the insulation and the in- sulating shell.. The fortunate inventor died happy leaving his part- ner with a duty anda fortune looming before him as his particular Nirvana. And how Mosler did fight! The case dragged for years, as is our happy Ameri- can custom, but Mos- ler won. Have you wondered who all those limousine owners in New York city are— those men who go to work at three in the afternoon and quit at three-thirty? They are A. R. Mosler, his sons, uncles, nephews and other relatives 360 Scrub Your Walls as Well as Your Floors by Machinery ITH the mechanical floor-scrubber already added to the long list of newly-contrived devices for insuring ab- solute cleanliness and saving the back and disposition of Popular Science Monthly The Gasoline Automobile in the Role of Railroad Locomotive OR long trunk lines, the steam locomo- tive has proven itself to be the most economical type of tractor. For short lines, and for factory yards or railroad terminals, however, the modern house- keeper, it is only natural that the next addition should be the mechanical wall- rubber. Let it not be imagined, how- ever, that the wall- rubber is for use only in the home. Un- like the floor-scrub- ber, it can be used wherever there is need of polishing. Adapted for clean- ing sunken panels, bands, spots, slabs and walls of marble, granite and tile, it can be used in the home, in the office building, in the cem- etery and in the sub- way with equal facility and good results. The machine is portable. It is driven by an electric motor which receives its power from an electric-light socket. The jointed arm to which the polisher is attached has a vertical reach of six and one half feet from the floor anda horizontal reach of eight feet. Two spiral springs counteract the weight of the arm, so that the operator has only to guide the polisher over the surface to be cleaned. A compensating shaft attached to the polisher keeps it pressed against irregular surfaces. Water. is forced through the polisher by a small pump operated by the de motor. A reservoir in the cabinet part of the machine holds the water. It is sup- plied to the brush in a con- stant stream, which may be regulated so that only a small amount, enough to merely moisten the brush, or. a copious flood for rinsing large areas at a time, may be ob- tained. No effort on the part steam propulsion is about the most ex- pensive. Whether the locomotive is standing idle*or not, steam must be kept up, and coal must be used continuously. The gasoline loco- motive which has now entered the field is doing all that the steam locomotive does,’ without the former’s waste when inactive. This gasoline lo¢o- motive is virtually the ordinary auto- The wall-rubbing machine is portable and is operated from any electric-light socket mobile mounted ona locomotive frame. The six cylinders of the huge gasoline en- - gine furnish one hundred and sixty horse- power. Connecting the engine shaft with the wheel driving-cranks on either side of the locomotive are a rigid gear transmission and an automobile friction clutch of ap- propriate dimensions. The side-bars ‘con- necting the wheels with the cranks are exactly similar to those on the regular steam locomotive. When the gasoline, which is stored on the top of the hood, is fed into the engine under full load conditions, the locomotive can ni seven modern freight cars filled to their fifty-ton capacity at a speed of six milesan of the operator is required except to guide the rubber. This locomotive, hauling seven cars, is driven by a six-cyl- inder gasoline engine giving one hundred and sixty horsepower shells of small caliber the cap in the cartridge-case‘of our which ignites the charge in the ‘breech of the gun. What a Match Is to Your Cigar So is a primer to its giant shell of the hub and hold- _ ing the anvil in place is a tight-fitting plug with several flash holes. Completing the primer is the closing-in disk over which the edges of the primer body are rivet- ed. Within the conical cavity in the Pete: Ores anvil base is a small ia shell soft brass ball which plays an important and interesting part. A highly explosive and ignitable substance is contained in the primer cap and held in place by a | tin-foil disk. This explosive sub- a 1 stanceisreadily prosecTILE set off by shock and is driven against the anvil block by the hammer of the gun on firing. The flash created passes through the anvil by way of small flash holes leading through the anvil nose to the cavity in which the soft brass ball is loosely confined, then through the flash holes in the plug, destroying the paper disk ie cemented to CARTRIECY ~—s the _top of the plug to prevent the powder in the magazine of the primer from working down through the flash holes. On the under side of the closing-in disk is another disk of paper to prevent the escape of the magazine powder charge through its flash slits. The flash transmitted through the anvil and plug from the explosion of the primer cap ignites the powder in the magazine, which, in turn, ignites the pro- pelling charge in the OWADAYS N every one knows what a shell looks like, and some of us can even differentiate between a high-explosive shell anda shrapnel. We are quite familiar with and read constantly of the destructiveness of the large 15- inch and 16-inch shells. There is nothing novel tousinthe general appearance of a shell such as shown here. We know that in the base of that shell is a little disk which corresponds with own shot-gun. This is the primer, . and while its existence is taken for granted, its mechanism and operation are less COPPER pre widely understood. fy Nd It is the primer cartridge case to drive the pro- jectile from the gun on its mission of destruction. Its function is similar to that of the cap in the base of a shot-gun cartridge, but the duties devolving upon the primer of an artillery shell are more complex. The primer has not only to fire the powder charge in the cartridge case, but also to prevent any of the propelling gases from escaping back into the The primer is composed of six parts—not including the explo- sives used—each one of which has a distinct and definite duty to perform. First, there is the primer body, which houses the operating mechanism and mediums ; and which screws into the base of | Beek 5 the cartridge case. In what may = eel ee be termed the primer ‘“‘hub,”’ there Bin te cartridge case proper. is the primer cap which corre- PRIMER The flame from the primer sponds with the cap of a shot-gun The primer ignites magazine breaks through cartridge. Next comes the anvil the charge in the this’second paper disk and escapes against which the explosive cap ee case to through the radiating flash-slits in . maar ve the projectile has to be driven to ignite the fom the gunon its the closing-in disk. charge. Capping thecentral hole deadly mission The explosion of the charge in 861 362 MAGAZINE POWDER FLASH SLIT CHARGE PLUG FLASH HOLE Popular Science Monthly Making Highways on . the Mud-Pie Principle OME enterprising f k in the Imperial Val desert, near Coachella, California, have discover- ed an easy and cacep ae ally inexpensive methc of securing public ‘high- ways without employing other labor than that necessary to flood the highway area with water. CLOSING DISK) TIN FOIL PRIMER CAP DISK How the primer works. the magazine creates gases, some of which attempt to escape by passing back through the flash holes in the plug, and this is where the soft metal ball previously mentioned comes into action. The gases impinge against this ball, and drive it into the base of the cavity where it acts as a cork, stop- ping up the passage and effectually pre- venting the gases from escaping through the base of the primer. This little ball there- fore forms an invaluable safeguard both to the gun and the gunner, at the same time insuring the efficiency of the primer. Such is the operation of the primer. It is an ingenious little mechanism without which the shell would be comparatively harmless and might be thrown about, dropped or ‘otherwise maltreated without danger of explosion. As for the primer itself, it would be no more dangerous, if it were not for the explosive cap in its base, than a shotgun cartridge with its cap removed. In fact, the primer of an artillery shell can be likened to an ordinary blank cartridge. Although primers -are completely as- sembled in the arsenals or factories in which they are manufactured, they are usually not inserted into the cartridge case until the projectile is being prepared for use— probably behind the lines on the battlefield. The transportation, therefore, of artillery ammunition can be undertaken with little liability of accident through explosion. The active agent controlling the destruc- tiveness of artillery shells, i. e., the primer, constitutes the one dangerous part of the shell, but separate from the cartridge case, the primer, even with its cap fitted, can do little damage. A blow on the charged primer cap is necessary to start things. ‘EXPLOSIVE Ry, es BODY CHARGE It is composed of six parts, each - of which has a very distinct and definite duty to perform In this simple way other- wise impassable desert paths are converted into excellent hard adobe, which makes as fine an subenolile road as asphalt. The highway in the accompanying illus- tration is invisible; it is two to three inches beneath the water. But when the water is drained off and the blistering hot sun bakes the wet ground into one long ribbon of a mud-pie, it does not loosen under the heaviest of traffic. Sluiceways are first constructed through the proposed highway and the irrigation waters from nearby ditches are then turned into them. After the water has soaked into the ground it is shut off; any remaining water is led into the fields-and used. again. The treatment costs nothing more than the labor necessary. to dig the sluiceways. The success of this method of quick road-construction depends upon the clayey character of the soil. When the water has been drained off, a hard, sun-baked adobe highway will result Lightning striking the steeple of the First Presbyterian church of Greensboro, North Carolina HE recent progress of knowledge concerning lightning has far out- stripped the ordinary reference books. Thanks to Benjamin Franklin and his famous kite, our great-grandfathers knew that lightning is an electrical discharge, and they were also familiar with the lightning-rod. These gentlemen, however, supposed that lightning commonly occurs in zigzags, with sharp angles, and not until photography was applied to the study of the phenomenon The Ben Franklins of Today They study lightning with the camera’ and at last they have told us what it is and by what it is caused the most important part—the earth termi- nal. The majority of the lightning con- ductors in America are consequently un- trustworthy. Unhappily these traveling impostors are by no means extinct, al- though increased knowledge is gradually driving them out of the field.’’ Besides, the construction of the rod itself has undergone improvement. Scientific progress in the study of lightning is due, to a great extent, to photography. Early investigators, such as Arago, Dove and especially O. N. Rood, had reached the conclusion that many lightning flashes are multiple, con- sisting of several successive discharges along an identical path, and had also formed a rough idea of the time intervals involved. Various forms of rotating disk were used in their (about thirty-five years ago) was this erroneous no- tion dissipated. Our immediate ancestors—in this country, at least—had like- wise learned to view the light- ning-rod with considerable sus- picion. Early in the nineteenth century thou- sands of defective rods were erected by ignorant or unscrupulous itinerant ‘“‘light- experiments. Far more accurate in- formation on this subject is now obtained by the use of a camera mounted ona vertical axis and swung in a wide arc, at a fixed rate, by means of clockwork. This method has been gradually evolv- ed from the crude process of merely holding the cam- era in one’s hands and giving it a side-to-side mo- ning-rod men,” whose names have become a by-word among us. These persons, to quote a recent authority, ‘‘used all kinds of fantastic and peculiar shaped terminal rods and con- ductors, the main object apparently being to make as great a show with as little material as possible. Their work is almost entirely confined to the upper portion of the conductor, to the absolute neglect of instantaneous. The flash seen to the left of the steeple was virtually That at the left of the chimney is a multiple flash, lasting for a fraction of a second tion—themethod followed by Trouvelot since the year 1888 and by Weber and Hoffert in 1889. The perfection of the moving camera is due, in part, to Larsen, in America, but especially to Dr. B. Walter, of Hamburg, whose achievements in. the photography of light- ning far surpass those of any other in- vestigator. Walter began by photographing, -with 863 { ; ; h A novel effect in photographing lightning by holding the camera in the hand and giving it a side-to-side motion the moving camera, artificial electrical sparks in the laboratory, and showed that such sparks begin with a brush discharge from each Popular Science Monthly The splendid photographs of Walter with a camera rotating at a known rate enable us to make an accurate time analysis of the details of the flash. How Long Does a Flash of Lightning Last? Such photographs show that some flashes are practically instantaneous, while others may last as long as half a second or more. When flashes of the latter class are photo- graphed by Walter’s method, the resulting picture shows several parallel streams of light, proving that a number of successive discharges occurred along the same path. These give to lightning its. flickering appearance. A photograph of this type taken by Larsen shows forty distinct discharges in a single flash, at average intervals of 0.0156 seconds, the total duration of the flash being 0.624 seconds. Photographs of this character also frequently show the pre- liminary partial discharges. of the electrodes, these partial dis- charges. gradually ionizing the air (i. e., making it a conduc- tor of electricity by breaking up its mole- Walter improved the moving camera by the addition of a stationary camera with which exposures are made at the same time, in order to show the actual di- cules into positive and negative ‘‘ions’’ or electrified parti- cles), between the electrodes, until finally the whole inter- val is bridged over by the spark. Some- thing similar appears to occur in a lightning flash. It is obvious that if a discharge of lightning has a sensible duration, the rotary movement of the camera will Growth of electric spark discharge, illus- trating the way in which the lightning flash builds up its path through the air rection of the flash from the observer. The same investiga- tor has more recently developed a stereoscopic process of photo- graphing lightning. Two stationary came- ras are set up side by side, several feet apart, and pointed in the same direction. When a flash is photographed, its position on the two plates is different with respect spread out the flash, as impressed on the plate, into a more or less broad ribbon. Most photographs of rib- bonlike streaks of lightning are, in fact, due to the accidental movement of the camera during exposure. When the camera is held in the hands, the occurrence of a flash com- monly causes the photographer to give an involuntary start, and this explains not only cases of ribbon lightning, but also various other peculiarities of ordinary lightning photographs. A certain amount of spreading in the flash is, however, due in some cases to ‘“‘halation.”’ Photographed simultaneously by two cameras about six and one half feet apart. By this method the actual distance of the lightning can be determined Popular Science Monthly to objects in the foreground, such as trees, buildings, etc., and, the distance of these objects from the cameras being known, the distance. of the flash can be determined. Lightning Sometimes 365 struck and comparing these quantities with those similarly obtained in the laboratory. From the strength of the magnetic field produced in the rock by the lightning, he estimated the maxi- Shifts to One Side ~ The ionized path of a multiple flash is not always station- ary, but is sometimes shifted a considerable distance by the wind. In the case of a photograph taken by Riimcker with a sta- . tionary camera, when the place where the lightning struck— and hence the dis- tance of the flash from the observer— wasaccurately known, the flash shifted laterally a distance of thirty-six feet during visibility. This phe- nomenon appears to -explain certain cases mum strength of cur- rent in the latter to amount, in some cases, to as much as 20,000 amperes. Humphreys, in this country, has recently examined a _ hollow copper lightning-rod, crushed by lightning (shown in the pho- tograph on page 368), and has esti- mated that the strength of current necessary to produce such an effect may have been as great as 90,000 amperes. Both estimates are very rough, since they depend upon as- sumptions that can- not be verified, but in which well-install- ed lightning-rods are ineffective. The in- itial discharge probably takes to the rod and is carried off harmlessly, but the dis- charges following keep to the ionized path as it is swept aside by the wind and strike a projecting corner of the building or a neighboring tree. Thus we have what ap- pear to be ‘“‘divided strokes;’’ but these are really successive strokes in different places at very small intervals of time. Several at- A brick stack cut in two by a stroke of lightning during a thunder storm they prove beyond a doubt that the currents in lightning flashes must be reckoned in thousands of amperes. Steinmetz estimated from the intensity of illumination due to a lightning stroke that the amount of energy involved was of the order of 10,000 kilowatt seconds, or 13,400 horsepower seconds. If we assume the duration of the flash to have have been .o1 seconds, this would represent a delivery of energy at the rate of 1,340,000 horsepower. tempts have been made to estimate the strength of cur- rent in a stroke of lightning. Pockels, in Ger- many, adopted the ingenious method of measuring the residual mag- netism in a mass of basalt rock near a But all this is little better than guess- work. What Causes Lightning? The origin of thunderstorm electricity, after having been the sub- ject of endless discussion for place where lightning had A good example of what is commonly designated as forked lightning, photographed with a hand camera generations, appears to have been satisfac- 366 torily explained about seven years ago by Dr. George Simpson, of the Indian Meteor- Popular Science Monthly cloud and earth, until ultimately the tension is relieved by an electrical discharge. - ological Service. The first stage in the pro- duction of a thunder- storm is a violent and turbulent uprush of air, resulting in rapid condensation of mois- ture in the form of the immense clouds that characterize such a storm. The drops of water constituting these clouds are re- peatedly broken up Lightning occurs in _ many forms and pre- sents many curious features, not all of which are fully un- derstood. Besides the ordinary linear flashes, we have the familiar phenomenon of “sheet lightning,’’ which is, as a rule, merely the reflection on the clouds of dis- tant linear lightning, by the air currents, and it has been proved by laboratory experi- ments that this process in- volves the separation of posi- tive from negative electricity. The drops become positively charged; i. e., they retain a greater number of positive than of negative ions. The latter are set free and carried aloft to the upper part of the cloud, giving it a strong nega- tive charge; while the positive ions are carried down with rain. If the process continues long enough, a strong potential gradient is set up between A house equipped with properly grounded lightning rods is practically safe from lightning TIN ROOF Kos : S > G. TILE PIPE How a woman was killed when a bolt struck the tin roof of an unprotected house _ but may sometimes be an actual difiuse dischate@e.jars, Walter Knoche, director of the meteorological service of Chile, has recently described a re- . markable form of sheet light- ning that occurs on a vast scale along the crest of the Andes during the warm season. The mountains seem to act as gigantic lightning-rods, giving rise to more or less continuous diffuse discharges between themselves and the clouds, with occasional outbursts sim- ulating the beams of a vast searchlight. These displays ATTACHMENT OF GUY WIRES WOODEN SUPPORT GUYED Lath ig ROO ORNAMENTAL IRON BRACE FASTENING wiTH STAPLES CONNECTION TO TIN ROOF SCREw EYE FASTENER MADE FROM SCREW KOOK Eee ‘PORCELAIN CLEAT 1) | cc b JOINT BETWEEN TWO CONDUCTORS The'modern method of fastening lightning radi to buildings. Insulators in clamps are no longer considered necessary except in localities where prejudice in their favor still remains disappears with a Popular Science Monthly 367 are visible far out at sea. Dr. Knoche once saw them from a distance of three hundred miles. Something akin to ‘Andes light- ning” has occasional- that the reputation of these devices has been fully rehabilitated in this country. The Weather Bureau has always strongly advocated their use, ly been reported from other mountainous regions of the world. “Ball’’ lightning takes the form of a fiery mass (not al- ways globular), which generally moves quite deliberately through the air or along the ground, and in many cases violent detonation. Many ingenious ex- planations of this strange phenomenon have been offered, but none of them is wholly satisfactory. An immense amount of statistical and de- scriptive information concerning ball light- ning .has been gath- ered in recent years; notably by Dr. Ignazio Galli, in Italy. ‘Do Lightning-Rods Help 2. Turning, now, to and Prof. J. Warren Smith, of that Bu- reau, has recently as- sembled some im- pressive statistics in their favor, compiled from the records of fire insurance com- panies. Damage by light- ning is comparative- ly rare in towns, where metal roofs, steel frames of build- ings, tall chimneys and other objects constitute an assem- blage of conductors capable of dissipat- ing the electrical charge of! passing clouds without ‘ dis- ruptive discharges between the clouds and the earth. On the other hand, light- ning is a thing to be reckoned with in the tural districts. It is estimated that the total property loss from this cause aver- ages $8,000,000 a the subject of light- A discharge of lightning of some duration, year in this country; ning-rods, it may be which is photographed as a broad ribbon of fire also that about 1,500 stated emphatically The correct location and distribution of lightning rods on various kinds of buildings persons are struck by lightning in the same _ period. Nine- tenths of these accidents occur in rural localities. At present, according to an estimate of the Bureau of Standards, not more than fifteen to twenty per cent of the buildings in the United States which are liable to damage by lightning are protected in any manner against it. Yet, to quote from the same authority, “such evidence as is available on the effectiveness of lightning-rods indicates that, taking rods as thes: come in the general run of installations, they reduce the fire hazard from lightning by eighty to ninety per cent in the case of houses, and by as much as ninety-nine per cent in the case of barns.”’ In Technologic Paper No 56 the whole question of protection against lightning is 368 Popular Science Monthly fully treated. *A few salient facts from.this Shooting Snapping Turtles with bulletin can be quoted appropriately here: an Ordinary Rifle _ A defective rod is not, as commonly ; stated, necessarily a menace to @ just before a snapping- turtle makes up his berth | preparatory to snooz- ing away a long win- ter, he makes a sort of itinerary of small lakes and ponds, apparently with the one purpose of stealing ducks and other water-fowl that live in game preserves. In this way, such ponds often become thickly tenanted with unwel- come inhabitants which are not easy to get rid of. The best plan is to keep a building. A poor rod is generally better than none. - Copper, aluminum and iron are all suit- able material for light- ning-rods. Iron must be galvanized. Contact between different metals should, in general, be avoided, to prevent the danger of electro- lytic corrosion. Con- tact between lead and copper is an exception. Insulators in clamps fastening lightning- _ rods to buildings are no longer used, except in localities where prej- udice in their favor still demands that means of a fence of coarse wire netting. If this precaution has not been observed and the - pond becomes infested, their use be continued. the quickest way to No system : of pro- A hollow copper lightning rod, crushed by a extermunate the si tection for oil tanks current estimated at twenty thousand amperes truders is to shoot has been devised which them with a good rifle. is accepted by oil companies as giving a Turtles are hard of hearing. You can degree of protection at all commensurate fire a rifle six times in their immediate with the cost. vicinity without scaring them away. But The loss of live stock in fields can be their keen sense of sight more than makes reduced by earthing wire [f- up for any deficiency in hear- fences by means of galvan- ing. They disappear in the ized iron pipe or posts at water the moment they dis- intervals of one hundred cover anything unusual. yards or so, and breaking up Snapping turtles appear to the electrical continuity of be very inquisitive. This the fence at intervals by in- weakness can be used to ad- serting sections of non-con- vantage. Choose a conven- ducting wood. Several ranchmen in the West and Northwest have adopted this method. It might be well to add in this connection and just at this time when powder. maga- zines and ammunition fac- tories are such an important factor in the world’s affairs, that the system of pro- main motionless for some time and watch your chance to fire the fatal shot. The foolish turtle will be sure to see something of interest and set out to investigate. He may swim a long distance, coming to the surface every few yards to inspect the object of his curiosity. When the turtles out by ient spot where you can re- - tection from paras by light- A half-inch groove he is sufficiently near, take ning for such places is at gouged in a monument careful aim and fire. If present far from satisfactory. y a bo g g your patience is as great as © 5 ees bf Life ag Pores, Aaslae: Ligne? by the curiosity of the turtles you will event- . S. Peters, Washington, 1915. For sale by the Superintendent ® of Documents, Washington, D.C. Price, 35 cents. ually rid the pond of them. there it is set going Popular Science Monthly - Target Practice with the Smaller Coast Defence Guns HEN practic- 369 The Biggest Red Cross Flag Ever—A New York Creation NE of the big ing with the smaller land defence guns, the United States army often uses a self-propelling target which is im- provised by the. handy men about the fort. The target is carried far out to sea by a launch; at a speed of from eight to ten miles an hour, and the guns begin their maltreat- ing of it in true American fashion! While these tar- gets are the simplest sort of craft, they afford about the best type of target known. Two pon- wa New York city department stores has set the pace in Red Cross flags. Across the Fifth Avenue side of the store is a flag seventy-five by one hundred feet; the hundreds of thou- sands who daily go up and down the street never fail to marvel at it. The flag was made in the store. It is ten feet larger than an American flag which formerly occupied the position it now holds. Note the con- gested traffic in the street. Fifth Avenue toons fourteen feet long and which stick only a few inches above the water, carry a marking flag. Usually, both pontoons are armored with quarter-inch boiler-plate, which is covered with gray target cloth. One of the pontoons carries the small * motor-boat engine. By means of its rudders, the craft can be made to ma- neuver straight ahead or in a circle. A _ buoy and cable are attached to the motor so that 4 it can be recovered from the bottom of the harbor should the pon- toon sink. ‘ The self-propelling target. Though the pontoons are This Red Cross flag that adorns a New York city department store measures 100x75 feet almost invisible, the gunners riddle them is rapidly becoming the most congested thoroughfare in the world despite its width. Traffic moves five blocks at a time and there are traffic police- men nearly every block for more than a hundred blocks of its length. The Complexities Involved in Making Shrapnel ERE the average layman able to grasp the staggering complex- ities of chemical and mechanical de- tails involved in the making of a shrapnel shell he would be amazed. For instance, one hundred and seventy gages are required to manufacture the combination time and percussion fuse for three quarter-inch shrapnel. The powder used must have the correct burning time or the explosion will occur too soon or too late. It is im- possible to obtain two powders with the same burning time, hence the burning time has to be determined on each lot of powder. This formerly required one and one-half hours; now it takes five minutes. Likewise, the time consumed in blending powders has been reduced from sixteen hours to fifteen minutes. O you ‘remember the old ‘Star’ > bicycle? If not, ask your father. He will tell you that it had a little wheel in front, and behind a very large wheel over which you sat. The little wheel in front was supposed to prevent you from taking ‘‘headers.”’ Show your father the accompanying il- lustrations of A. F. d’Harlingue’s air- propelled unicycle and he will say at once: “Why the man has simply put an air- propeller and an engine on a big old Star!”’ But the difference between the old “Star’’ and this curiously ingenious and yet most impractical invention is this: The old ‘Star’? was a simple, operative invention; the air-propelled unicycle is much too complicated to operate success- fully. The PopuLAR SCIENCE MONTHLY has not pictured every one of the businesslike gears and elaborate controls which are supposed to adapt this machine for high- speed travel and racing. It’s unnecessary to do so. But it has emphasized the two fanciful and fundamental features, namely, the unicycle design intended to result in a vehicle running normally on one wheel only and, secondly, the use of an air-screw for propulsion. The fascination of com- bining these features may have arisen from the recognized difficulty in applying engine power in a unicycle by ordinary mechanical means, so that the use of an air-screw came to appear as the happy solution of a problem. Compare this construction with a motor- cycle and especially with a pace-making machine having the driver’s seat at the extreme rear. With the motorcycle, the practical speed is limited only by the driver’s ability to endure the jolts or his willingness to take chances. The wastage in the transmission of the engine is small. The resistance in the wheel spindle-bearings is evidently insignificant compared with that to be looked for in the corresponding bearings of the unicycle, which are those of the three roller disks shown in the engine- carrying frame, subject to constant side pressure from a bevel-pinion drive. The loss of engine power in the transmission of the unicycle is enormous. ‘There are con- stantly in mesh a large number of elements. At turns, there are, in addition, two hand- operated worm-gears for turning the T- shaft of the air-screw upon its vertical pivot-pin (against a considerable resistance when the screw is going), and this further operates a train of three spur-gears to make the front wheel participate in the turn and—when it is on the ground—help in directing or stopping the big wheel. The loss of efficiency due to the many transmission gears is small, however, com- pared with that of the air-screw, which cannot be more than three and one-half feet in diameter so each blade is less than twenty inches long. An air-screw of these dimensions, at the present stage of knowl- edge, has about one-fifth of the efficiency and one-tenth of the capacity-of a screw, ~ with fortysinch blades and can scarcely absorb more than fifteen or utilize more than two-horsepowers at the utmost ve- locity that can be imparted to it through gears. On hills, the machine would be reduced to very low speed with high fuel consumption. An air-screw éven. so small as three and one-half feet in diameter would be dan- gerous to bystanders and wayfarers; a larger and more efficient one would be entirely out of the question on the road. Ordinarily the front wheel, which some- what spoils the unicycle idea, is supposed to hover in the air when the machine is running, the driver sitting on a sliding seat, balancing his weight against that of the front structure by pushing the seat to the balancing position. The claim is made that by shifting his seat he can make the air-screw inoperative, but nothing is shown to substantiate this assertion. To the front wheel a brake mechanism is secured, to be operated with a long rod, and the inventor believes that this brake 370 Here’s the Air-Propelled Unicycle 4 Some mechanical misgivings about a fantastic invention : can be operated with safety even on a curve, because the little wheel is then turned into the curve by its geared con- nection with the air-screw. The safe and sane brake system of the motor-bicycle shines by comparison. The only worth-while advantage of a unicycle over a bicycle is that it can be steered by simply leaning to one side, but this solitary advantage, exemplified in a boy’s play-hoop and largely utilized in the old ordinary and ‘‘Star’’ bicycles, is de- liberately abandoned in d’Harlingue’s con- ‘struction. By rods (one of which is shown) _and the worm-gears before mentioned, the air-screw is supposed to be swung to the side in order to turn the big wheel. All the complications arising from this mis- understanding of the case are accepted. “What are the supposed dimensions of this unicycle? They are indicated by the distance from the seat to foot-rest, which must be about three feet to fit an average man. That gives the diameter of the big wheel as nine to ten feet and that of the air-screw three and one-half feet,.as men- Chassis i oo ll Transmission housing 4 , AS Wy, UW . VY Popular Science Monthly 371 tioned before. The chain-drive is about six feet long. The aluminum shield in front of the driver is bent and hammered from a sheet-at least six by four feet. Though in this class of vehicles relative proportions are vital, the engine and its dimensions, as shown, must not be taken seriously. By estimating bore and stroke on scale with the rest, they would indicate sixty to eighty horsepower at 1500 revolu- tions per minute, but then the engine is also shown as watercooled, yet with no provisions for disposing of a radiator or other bothersome detail. A jolly sport machine might be produced on the basis of d’Harlingue’s general idea by radical simplification of his design, including the omission of front wheel and all gears and placing a little high-speed one-cylinder engine directly behind the air- screw. The shaft could be tilted upward a little and the diameter of the big wheel reduced to five or six feet. Braking could be done by drags at the rear under foot or hand control. But an engine starter would be found indispensable. Pneumatic tire Inner rim Win WM) Wy YY Shield Steering wheel for. } { | airy screw (NM Alt ! | RY — / « = OD A SS jf “AIS, em re Ti | Brake band Sean Steering and control wheel not used in Shock absorber high speeds jeg ra AN fs ————a Balance rod 4 Seger — Brake mechanism Al, Foot rest is Roller channel Roller If a unicycle could be driven with a smaller resistance and at greater speed than a bicycle, if _ it could be built more economically or compactly or could be operated more safely or enjoyably, and if small air-screws could be made to apply a thrust against the atmosphere without a vast loss of power as compared with the mechanical rotation of a driving wheel, the combination might lead to desirable results. Alas! Each of them is inferior, and their combination multiplies their degree of inferiority compared with the motor-bicycle with mechanical transmission A scientiric cooker for meats, poultry, vege- tables, fruits and cereals. Above is a_ sectional view of it. It has three bot- toms designed to prevent the utensil from coming into di- rect contact SSSSSSS SSS SSS SSE SEE SU Housekeeping Made Easy Mai re Le PMID MATT LOTTE Tea TOM lle OOM MUO ULE il tbe i A unique cover for the humidor which is a com- bination affair on the order of a smoker’s kit. It holds pipes and matches and serves as an ash with the flames and to ‘concen- trate and con- into the top serve the heat of the humidor Coring apples and cutting them into quarters in one operation. You simply press on the handle and give it one quick turn Switc HANDLE'FOR DRAIN PIPE The newest and od- dest design in racks for books,magazines and newspapers The electric light stand for the li- brary also serves asa book rack The kitchen table and_ dish-washer. The washer is oper- ated by electricity A machine for sanding floors evenly A skillet with a removable handle and does away with the back-breaking an outlet for steam can be used labor involved in sanding by hands either for baking, frying or boiling book table pro- vided with a lamp which may be ad- justed from forty- eight to sixty inches in height. The table itself is twenty-four inches high and twelve inches square. Both table and lamp standard are of mahogany. About six books can be accommo- dated between the two side braces on the top of the table, and as many more on the shelf A modern laundry in a Long Island home. The electric washer with ringer and the ironer have 30... an = oats 20 Refrigeratoy Db Li Bi dil changed the usual wash day into wash hour You can fold this gas range out of the way so as to use the space below it fora table. Itis so made that it may be con- nected with flexible or fixed tubing. If flexible tubing is used the range may be disconnected and tucked away in a closet. Taking it out again and set- ting it up for use when needed is but the work of a mo- ment. All parts are light in weight Two photographs mounted on a pivot fit, back to back, in this frame. The view on each side is six by eight inches. The stand and frame are attract- ively finished in burnished gold A | a A simple and inexpensive book rest which can be adjusted in three positions for use. Two of the positions are shown here. The ledge of the device holds the pages of the opened book flat 373 Food For The Taking. The dogfish, the sable, the goosefish, the huge whale, the giant kelp—all are ‘ By A. M. valuable sea foods that we throw away. Eat them and reduce the cost of living Jungmann NE of the reasons why we suffer from the high cost of living is because we refuse to eat much of the food which we have. ° Millions of dollars’ worth of wholesome, fine- flavored fish are thrown away each year. And as for. the marine vegetables which can be had for the taking all along our shores—the majority of our people do not know that they exist. Take the case of the goosefish, a food which pound for pound equals ‘beef steak in protein (flesh- building material). Only seventy-five per cent of a pound of sirloin is edible; ninety per cent of the goosefish is edible. Hence, the goosefish equals the steak in available protein content. Yet we go on blithely throwing away ten million pounds a year of this valuable food fish. The absurd part of this startling extravagance is that we reject the Tread The Greedy Goosefish Is Good to Eat The goosefish averages about three feet in length. It is not unusual, however, to find larger fish, The broad body and large head surmounted by a tuft which acts as a lure for its prey, the enormous mouth with its double row of strong teeth all tend to make its appearance repulsive. It eats any living creature it can overcome. Fishes, lobsters, squids, crabs—even water- fowl, such as ducks and geese, are all on the goosefish’s _ bill-of-fare. To eat “like a horse’ is a common expression, but to eat like a goosefish would better express the idea of a huge appetite, because the weight of a single meal of a goosefish will be half as much as the weight of the fish itself profitable. Figures gathered just be- fore the war show that they annually sold over five million seven hundred thousand pounds of this fish. The Mystery of the Tile Fish Another fish which has never attained the popu- larity it deserves is the tilefish. It is the center of one of the most baffling marine mysteries. ing about this fish had ever been recorded until 1879, when. a_ schooner fishing off Nantucket caught several thousand pounds of this large and beautiful fish. The cap- tain of the schooner was sufficiently interested to send one of the fish to the United States Fish Com- mission where ‘it was found to be new. Efforts were made at once to establish a fishery, but before anything defi- nite could be done goosefish simply be- cause we do not ad- mire its looks. It is so exten- sively used in Ger- many, where it ap- pears under the name of See-Teufel (sea-devil), that the catch on the North Sea does not supply: the demand. Before the war large quan- the tilefish were all mysteriously killed in March, 1882. The first news of the tragedy was brought in by a skipper who said he had sailed for fifteen miles through a mass of dead and dying fish which were floating on the surface of the water. The disas- ter was investigated tities of this fish were imported into Germany from Great Britain. The Scotch and English fishermen found the goosefish very It is a sort of isinglass. transparent and shiny. Kanten Is Made in Japan from Seaweeds It is thoroughly white, semi- It is extensively used for food in the form of jellies, candies, pastries and for anything which is prepared with gelatine. It is much superior to the common animal isinglass. production of ‘‘kanten’’ are not available, but in 1902 three million pounds were made with a valu- ation of sevén hundred and fifty thousand dollars 374 Late statistics of the by the United States Fish Commission and it was estimated that the dead fish covered an area one hundred andseventy Noth- — a? ee bottom of the sea, but as it tropical fam- probably had CPS ee ee en om ey Po t The _ tilefish, like the cod, miles long and twenty-five miles wide. The number of fish to meet this untimely end - was one billion, five hundred million. _ This phenomenon was so amazing that the Bureau of Fisheries decided to inquire into the matter and the result of the find- ings indicated Popular Science Monthly 375 it is known as the grayfish it is beginning to be accepted. The grayfish is a fine looking fish, very trim and sporty with its clipper-build and smooth shining skin. It is wonderfully quick in its movements, which is necessary for a creature that the fish died of chill. dwells at the comes of a ily it cannot withstand the cold as can the cod. with its pirat- ical propensi- ties. It weighs when grown from five to fifteen pounds, the average for adults being seven pounds. The hide looks scale- less, but is in reality cov- were no longer protected by its warmth and found themselves in chilly water, which proved too much for them. . A few years after the disappearance of the tilefish the Gulf Stream was found to be gradually approaching the coast. In 1892, the warm water of the Gulf Stream flowed over the bottom of the: New Eng- land coast and in the summer of that year the Fisheries schooner, Grampus, caught a few tilefish. But for ten '. There was ered with fine, evidence that sharp parti- the Gulf cles very Stream had rough to the receded; as touch. The it moved off — skin is used shore, the The Imitation Sturgeon of the South for polishing tilefish lying GN cehectd Exc gregia In te drechomeee i eaten by che metal, ivory at the bottom negroes, who are very fond of it and wooden articles, as it is much like emery cloth. The liver produces an oil which finds a ready market in the arts. The utilization of these fe eraduty makes it possible for the canner to supply the fish to the consumer at an unusually low price. The wholesome grayfish has been eaten and-enjoyed by the people living on the shores of the Mediterranean since some long distant period lost years not a single fish had been found on the old grounds, although painstaking search had been made all during that time. “What’s in a Name?” The Dogfish Becomes the Grayfish in the shadows of an- tiquity. Doubtless many an American so- journing in Europe has smacked his lips over a dish of savory grayfish and has wondered why we have no native fishes quite so delectable. The Wastefulness of As an example of “What’s in a name?” take the dogfish. As long as this excellent food fish was called by that unattractive name the public would have none of it. Now that to the Our Newest Deep-Sea Food Fish The tilefish should prove to be very profitable heries, because if the fresh fish are caught in such quantities that their sale in the fresh state would not pay they can be Salted and smoked like finnan haddie, which, when smoked, they resemble in flavor. fish are ever smoked extensively a profitable by-product would be found in the sounds, or swimming bladders, as they are valuable for the production of gelatin or isinglass California On the Pacific coast the people are just as wasteful and extrava- gant as they are on the Atlantic, when it comes to refusing fine flavored If these 376 Popular Science Monthly See The Japanese Eat Kelp; the Californians Make Potash from It Kelp is gathered in Japan from July to October. The seaweed is taken into open boats. by hooks attached to long handles. It is dried and cured on the beach. When cured, the plants are trimmed and packed. Plants of the same size are ‘packed together, making neat, uniform bundles cause there has been no market for them. — ' The pecliaely firm flesh of the sable fish enables it to stand shipping very well. It may be frozen and successfully shipped throughout the coun- try, even as far east as New York. The famous cod has a fresh water cousin known as the burbot. It is found in the lakes and larger streams of all the countries in the world. In this country it abounds from the Ohio and Missouri Rivers all the way to the Arctic regions. The meat is very like cod. As the fish is plentiful and its price low it should become a general favorite. However, « none of our people may become fish. There they throw away large quan- as fond of it as a certain Italian countess tities of sable fish, which until recently re- of the sixteenth century w o spent all her joiced in the name black cod—why, is a_ income on burbot. mystery, since it is not even related to the cod family. Why Not Whale Steak with Currant Jelly? The Department of Dietetics of the The sea produces meat which may be University of Washington states that the sable fish is ‘“‘excellent from an economic as- pect, as there is substituted for beef. That is to say, all the crea- tures which swim “in the sea’ are*not fish. Whales and little waste, being The Burbot Belongs to the Cod Family porpoises are almost fr ee fr om The burbot lurks in holes at the bottom of the waters mammals just like bone and requiring all during the day. At night it steals forth and preys cattle and sheep. ‘ ; upon other fishes, crawfish, insects and fish eggs. < A very little time for It has a stomach’ which is’ very elastic, enabling it Their flesh is really : : S: to consume large quantities of food at a time ut ; i cooking. It is sult- it pays for this appetite when it begins to grow meat. Whale able for the hum- old, for -then it loses its slim, graceful lines and steak was served becomes heavy, flabby of flesh and blest home on ac- je “potbellied” this summer in western hotels and count of its price and for the millionaire’s table on account of its fineness of texture and delicious flavor.” The adult fish weighs about fifteen pounds, although much larger ones are frequently taken. met with a favorable reception. A juicy piece of sperm whale steak with currant jelly makes a fine meal. The whale steak is very like beef in texture al- though darker red in They are found in Seaweed Is Also the Basis of Isinglass abundance in the coast from San Fran- cisco to Alaska. Halibut fishermen have ‘‘fishy”’ taste. A bundle of “Slender Kanten,” or seaweed isinglass. deep waters off the It is only available from December to February beef color. The flavor is much the same as It has no slightest trace of The United States Govern- been catching these fish for years, but ment tests show that it contains about they have always thrown them away be- four per cent more protein than does beef. Popular Science Monthiy — ST7 In Seattle, Washington, and Portland, Oregon, whale meat has been selling in the market places for ten cents a pound. It was first put on the market in May and it has been selling steadily ever since. Whale meat has been used in Denmark to feed the soldiers. Eating the Vegetables of the Sea With your whale steak you might have a dish of dulse or kelp if you only knew how pal- atable these marine vegetables are. And you might top off your dinner with a pudding made from seaweed isinglass. — In Ireland, dulse is a much favored vegetable, as is laver, which is called ‘“‘sloke.’”’ Both these vegetables grow plentifully under the water along all our Atlantic coast. Our seaweed resources are equal, if not superior, to the Japanese or those of any other country. Yet, while Japan prepares seaweeds each year which exceed $2,000,000 in value, the total value of the marine vegetables pre- pared in this country is $35,000. A Pirate of the Deep Like the bluefish, cod and haddock, the grayfish subsists on a purely animal diet. It feeds on fish, crabs, shrimp and lobsters. The grayfish,-like the goosefish, enjoys a healthy ap-’ ‘| petite. Indeed, it is so raven- ous that it does not hesitate to rob fishermen’s nets and trawl lines. It has splendid teeth of a knife-like sharpness and jaakes a general nuisance of Japanese women sorting kelp. is used extensively, throughout Japan and China, for food itself by cutting to pieces fishermen’s gear in its piratical efforts to get the go meal it always craves. Neither the trawl fishermen nor their brothers of the nets are spared by these unscrupulous sea thieves. Most fishes produce innumerable eggs, but the grayfish is an exception, Six or eight grayfish are born of the mother fish, not helpless as young creatures usually are, but full of fight and spoiling for a scrap. They are thoroughly well equipped to care for themselves from the moment of birth, and they enter into the battle which is the everyday program of marine life with the odds in their favor. Because of this early start and because it is not generally used for food the propor- tion of grayfish to attain maturity is much in excess of that of other fishes The horned pout, or catfish, another valuable article of food much despised because of its looks and its whiskers When prepared, this article The industry in the United States is practically confined to Massachusetts, and but a single species is used—lIrish moss. It is true that in Mon- terey and Santa Barbara Counties in California, Chi- nese fishermen dry certain marine algae for food, but the value of thisamounts only to about eight hun- dred dollars a year. .2 Kelp is an enormous seaplant which abounds along the Pa- cific coast. A full grown plant will have a stem three hundred feet in length which bears at. the top an air bulb. From this bulb grow fifty or more giant leaves, each one of which will attain a length of thirty or forty feet. This plentiful vege- table is entirely ignored by us, but the Japanese prize it highly. They make what is known as “kombu”’ from kelp. Because it fades in the curing process, much of it is dyed green, just as French peas are dyed to give them their pleasing color. dyed ‘‘kombu”’ is used as a vegetable and is cooked with soups and meats. It is even made into a sort of con- fection by sugaring small strips of it. “Kombu” appeals to the Occidental taste when crisp sticks of it are broken in small pieces and served as a cereal. This shredded, 378 HE combination of a pole, two Popular Science Monthly The Broomstick Periscope—How De- tectives in Kansas City Used It hand mirrors, a monkey- wrench, a torn curtain and a bureau looking glass solved a mystery case in Kansas City, Missouri, detectives baffled the for a long time. detectives wanted to discover what was go- ing on in a certain which The figures it was decided to cut the skirts off at seven, eight and nine inches from the ground, making up the deficiency in the width. The little matter of the cost of the high shoes did not disturb the manufacturers. Music Hath Charms Even in the Desert HE British Tom- - my must have his fun; otherwise he wouldn’t make a good room. fighter. When the Tom- _. By tying a hand mir- ‘mies on the western front ror to each end of a are given a few days’ visit short broomstick and by to ‘‘Blighty.’ (the soldier’s holding the device out- side the window with a monkey wrench, the nity first to name for England), they are welcomed with open arms by committees who do nothing else but make the visit at home a continuous round of pleasure and diversion. They detectives are taken to theaters, ath- were able letic events and pink teas to see inside until, as one Tommy said, - the room. recently: ‘‘Trench life is a Fortunately Opéting i dull affair compared to what they found curtain they put you through in opportu- Wencl} = =- Blighty.” Even the Tommies sta- Sed as . REE pganiers tioned on the blistering sands of Sahara must have their entertainment. In the photograph below is shown a company of soldiers transporting a piano across the Sahara sand for use at an out- post. The piano is being moved on a sand sledge, which is the same.as a snow sled except that the runners are wider. tear a hole The periscope device which rivals any of in the cur- the tools used by Sherlock Holmes. The tain. detectives arranged first to tear a hole in the curtain and adjust the mirrors Why Are Skirts So Short? To Help the Poor Shoe Dealers ARLY in the season manufacturers of women’s dresses decided -that the short, narrow skirt must be discarded. Not for puritan- ical reasons, but because the manufacturers of materials were losing money. ‘‘Make them long and full,’’ was the verdict. ‘‘No!” retorted the shoe manufacturers. ‘Do you want to put us out of business? Make them as full as you like, but short— and shorter!’’ The argument waxed hot and revealed the fact that every inch added to _ |. the length of women’s dresses means a loss of $10,000,000 a year to the shoe business. In the face of such appalling Transporting a piano across the Sahara to a British outpost. A sand sledge with wide runners takes the place of a van Popular Science M onthly Desert Sand-Shoes for the British Troops in Palestine HE, British troops in the Sinai desert, in Palestine, have found a way to make their feet as sand-worthy as the camel’s. By weaving a stiff network of heavy wire and attaching it to their shoes, they are able to travel over the finest desert sand without sinking ankle - deep in it. They have adopted the principle of the snowshoe. It is said to be physically impossi- ble for a man to walk over desert sand for more than two days with or- dinary shoes. At the end of that time the toes and heels become pain- fully inflamed and the skin comes off. No doubt the troops suffered untold agony be- fore they devised the sand-shoes. Loading Coal-Baskets Automatically From a Motor-Truck ANY residences,: particularly those in the suburbs of cities, are built far back from the sidewalk so as to leave a neat lawn. Coal ‘cannot be shot into the cellars of such houses directly from a vehicle. It must be carried in in baskets. That necessity brought forth the new motor coal-truck illustrated below. The vehicle has a table at the rear carat emaciiaaine eemae - we The snow-shoe principle applied to sand- shoes for traveling over the blistering desert The inside of the truck body tapers down to an angle at the rear so that the coal will run out easily. When the baskets are filled the pulleys lift them up shoulder high 379 on which are carried four large baskets, -each holding two hundred pounds of coal. The table is lowered by gravity so that the baskets are level with four spouts in the rear of the truck body. Gates in these spouts are opened and the baskets filled in one operation. After this the table and baskets are lifted up to the height of a man’s shoulder by means of ropes and pulleys operated from the driver’s seat by an-~ hy- draulic hoist driven, from the truck en- gine. The men place the baskets on their backs with- out any lifting, carry them to the residence cellar and return with the empty baskets, after which the op- eration is repeated. The rear of the body is tapered to an angle of seventy-five degrees sothat the coal will run out without difficulty. The entire operation of filling the baskets and lifting them shoulder high takes seven seconds. Five tons of coal are disposed of over a sixty-foot carry, in less than twenty minutes. With this novel: body the truck is able to deliver coal at the rate of thirty-two cents a ton for labor, whereas by the former horse methods it cost fifty-two cents. Five Billions to United States Is Like Three Cents to a Man With a Dollar HO shall say how many ten- figure loans a nation can make before she will be bankrupt? England, with an estimated wealth of eighty-five billions, hasmade three great loans, aggregating ten billions, the last one being the largest single loan ever floated. Germany has made five loans since the beginning of the war, yet her wealth probably does not exceed eight billions. Con- sidering these figures, a five- billion-dollar loan in the United States, having an estimated national wealth of two hundred and twenty bil- lions seems small. The Mother of thie Su biases As a complete floating naval base, the submarine mother-ship is indis- pensable in our submarine program because of our two long coast lines S everyone knows,—and as Germany A long ago learned to her sorrow,—the Strait of Dover has been planted and re-planted with British mines until it would be sheer suicide for a.German submarine to attempt to pass through. In order to attack England’s shipping, German submarines have therefore been compelled to travel all around the British Isles. In making this tedious detour, a great tax is laid upon the submarine’s com- paratively delicate machinery. And since this journey must be made under the water most of the way, an even greater strain falls upon the crew. If the submarine and its crew ever get back, both will be in dire > need of repairs. Here is where the mother-ship justifies her name. On returning to its assigned harbor and. signaling by wireless to its parent-ship, the submarine is immediately taken in between the ship’s steel hulls and is finally sheltered in the tubular compart- ment amidships. The compartment is water-sealed and huge pumps on the mother-ship are started forcing the water out—thus converting the compartment, in effect, into a. wonderful floating drydock. The submarine’s crew are received by the mother-ship and are accommodated in extra cabins especially laid aside for them. Here they can sleep on real beds and take their well-earned rest. Meanwhile, the lathes and forges are busy fashioning new parts and the duplicate submarine members carried by the mother- ship are mounted in place of those worn out or damaged. The duplicate mechan- isms are stored mostly on the decks. The heavy lathes, on the other hand, are mostly below; not exactly below deck, however, but more correctly, in between the two walls of steel which together make up each of the twin hulls. Occupying the re- maining space between these steel walls are ballast and fuel oil tanks, torpedo and other stores. In here also, and in the hull at the front of the tubular docking compartment—which at this section looks like the hull of any ordinary ship, are the marine oil engines for driving: the ship. The cast-steel propellers with which these connect project backward, one from each of the twin hulls. In a few days’ time, the submarine is completely overhauled, and her food and fuel supplies ‘are replenished. Those of her original crew who are unable to stand the strain of the next journey are relieved by trained men on the mother-ship. When the new submarine crew have taken their _ places, the docking compartment is flooded, the ballast tanks trim the ship further, and the submarine takes to the sea again with renewed strength. When we consider that one ship can mother a flotilla of six sub- marines, scheduling four on active duty, one in reserve and one in repair, the stra-. tegic importance of this type of vessel in the present war is evident. Without put- ting back for new supplies, and without touching her own supplies, she can re- juvenate a complete flotilla four times! After a submarine has been on active duty a number of months, she is likely to develop a weakened hull, a fault which cannot be detected by ordinary methods. Here again the mother-ship is of prime importance. She is specially equipped to convert her tubular compartment into a testing dock. Her powerful pumps will force the water into the testing dock until the conditions are simulated that exist at the dizzy depth of two hundred feet below the water’s surface—a submarine rarely dives down more than fifty! The testing crew within the submarine are in constant communication by telephone with the men at the pumps. If any weakness has developed, leaks will soon be noticeable, and the water pressure can be relieved before further damage results. These leaks, and whatever other faults are found, are. noted and subsequently repaired. The last, but not the least important function. of the parent-ship, is that of a salvage boat.~ If a submarine sinks within reach of divers, a mother-ship will be able to save her, provided she can be suffi- — ciently protected from the enemy by friendly warships or by her own quick-firing guns. Mother-ships have a cruising radius of four thousand miles and they can speed towards the place of disaster at the rate of ten knots. Expert divers are ready to wrap a cable around the sunken submarine, and powerful cranes are made ready to haul it up. 380 What the “Mother” of a Submarine Flotilla Looks Like T DECK RAILWAY POR HAND UNG REPAIR STORES 49s/ fan WN ! BED-PLATES FOR ENGINES, WHICH ARE DRIVEN BY THE SAME OICFUELAS THE SUBMARINES, SIM- PLIFYING STORAGE AND CAN ALSO, TOGETHER With “AUYIL ARY ENGINES, BEUSED FOR TRAINING PROS: PECTIVE. OFFICERS AND CREWS OF SUBMARINES. AUXILL ARY MACHINERY INCLUDES DYNAMOS FOR RE- CHARGING THE BATTERIES AND THREE COMPRESSORS LING THE AIR RESERVOIRS OF SUBMARINES Manet Sic RES Re a The mother-ship of a submarine flotilla must discharge manifold duties. She is responsible for the supplying and the repairing of six submarines, keeping them in prime condition for active service. In her central testing dock, she must periodically subject each submarine to tremendous pressures so that disasters from weakened hulls are averted. In brief, she must act as a mobile naval base—a base which can furthermore salvage any sunken submarine within reach of her divers $81 vs a aE rT = P ‘ ‘ A. ; Sores. (MF fortinoes ff yvonsirs onze cae. ee er . & s 382 The Star Spangled Banner in Brick —A Feat of Chicago Masons OMETHING out of the ordinary in the way of flags was constructed by a Popular Science Monthly bers of an Italian scouting party about to. partake of their midday meal. Their faces and hands grease to protect them against the burning rays of the sun, which are doubly strong are besmeared with black ~ Chicago when re- company flected from recently. the snow. It is a flag They _ pre- of burnt- fer to use clay — brick vaseline, that neith- rere but that is er time nor ash laa too expen- elements NE en sive. The. can destroy or mar. So far as we know, it is the only flag of its kind in the world. — It is fully thirty-two i eek SF . ie but it in- jures their eyes so that have to be WO Fe: inches high “Old Glory” reproduced in burnt-clay brick. Even the stars are Needless to by forty- of brick. They were chiseled out and finished in white enamel say, the eight inches black wide. The red stripes consist of red, grease and the sun glasses make the Ital- vitrified brick, the white stripes of matt- glazed brick, and the blue stripes of dark blue-enameled brick. The stars are of brick, too. Forty-eight of them were cut from white enameled brick with chisels and were laid in the blue background with blue cement mortar. The masons who are responsible for the flag first thought of pasting stars cut out from oilcloth on the brick to represent the forty-eight States. Finally they decided not to fake the flag, and hit upon the idea of cutting the stars out of’ individual bricks. Needless to say, this was a big task, but the result was well worth the labor and means expended. Italian Soldiers Paint Their Faces —But Not for Beauty HE Italians holding down trenches in the Alps have two enemies to deal with, the Austrians and the snow. Of the two the Italians prefer to en- counter the Austrians. As it is, they have to face both and get along as best they can. In order to do this they supply themselves with gunpowder and rifles for the Austrians and black _ians excellent targets against a background of white snow. However, the Alpine Italian troops do not always use grease and sun glasses. | When there is hot fighting to be done in the Alps, they don snow-white suits and even paint their rifles white. In such a uniform they are practically invisible. snow not: only burns. the faces! of troops. sun glasses - grease and glasses for the sun. The photograph shows four mem- from burning the faces Black grease and sun glasses prevent the sun and injuring the eyes of the Italian troops fighting in the Alps Cleaning the Air Fed to Automobile Engine Cylinders -voys almost hidden in F interest to every automobilist, and to the Government whose army trucks run in con- clouds of dust, is the car- bureter air-cleaner shown _ in the illustration below. The device is distin- guished by its simplicity; for it has no moving parts. By extracting the dirt and grit from thee air sucked through the car- bureter into the engine cylinders, excessive wear on pistons and_ piston rings is avoided, as well as scoring of the cylinders, pitting of the valves and cutting out of bearings. The cleaner operates on the principle of The air is sucked near the top and down through the two centrifugal action. curved square - sectioned tubes. The circular path of the air down through the tubes throws the heavier particles of dust to the out- side so that when air and dirt are sucked through the ends of the tubes, the dirt drops down on to a cone- shaped shield in the bottom while the air passes up and out through the center of the top to the engine cylinders. The dirt slides down off the cone into a pocket beneath, which is cleaned out as re- quired when the engine is stopped. Another point in favor of such a cleaner is that it Air ine reduces the carbon forma- tion. The dried out lubricant remaining in the cylinder _after each explosion attracts the particles of dirt usually sucked in with the fuel air, forming points on which carbon readily collects. Popular Science Monthly In circle: Smoking the rifle sight for use when firing in the sunlight. Above: In - rs TT. Bo et = © 4 b \ a Se rect Dirty air Air drawn to carbureter Dirt fallsto ottom Clean eee The principle of centrifugal action explains the working of the carbureter air-cleaner Using the rifle strap as a sling-grip Some Rifle-Firing ‘‘Kinks’’ That Are Taught the West Pointers HE average recruit who starts in at West Point knows as much about the fine points of rifle firing as a long- shoreman about flying. First he masters the elementary steps— the manual of arms and the cor- firing positions. Then he must learn a thousand facts not mentioned in the ‘Drill Regula- tions.” for instance, is the smoking of the Among the rifle kinks, glass rifle sights for work in the sun. By simply holding the sights over the flame of a match—or better, over an alcohol flame—a_ light layer of lampblack is spread over the sight which enables the soldier to fire even when he is directly facing the sun. And when his back is to- wards the sun, the reflected glare is eliminated so that he can work without danger to his eyes. Another kink is the doub- ling up of the ordinary rifle- strap in order to use it to ob- tain asling-grip. By making the sling short enough, it is possible for the left hand to obtain a vise-like grip on the rifle. This helps consider- ably in steadying it. 384 Turning a Page of This Biggest Bible Is Like Opening a Trap-Door Popular Science Monthly ten times that of the ordinary pleasure car. At the present time the spring occupies a position above the roof of the factory. MAN- Here it at- uscript tracts about Bible meas- as much at- uring five feet two inches by three feet ten -inches has been prepared for a Bible cru- sade by the Oxford Uni- versity Press. When open, the book meas- ures seven feet ten inches. It is so big tention as it did when a score of workmen were busy constructing it. When asked for what pur- pose the spring was -being made, a workman facetiously ‘remarked, “For a car. to carry the man who wore the and bulky é that nis ap A Bible big enough for a family of giants. Twelve cial steel thousand persons have. been engaged in preparing it framework is necessary to keep it in shape. Turning one page is like pulling up a trap door, only the page is much lighter than a door. On the other hand, the cover of the Bible, which appears very distinctly in the ac- companying photograph, is heavy. It weighs as much as twenty good-sized books. Twelve thousand persons have been en- gaged in preparing the Bible. Perhaps a hundred thousand will have helped before it is completed. A Spring Big Enough for an Auto- mobile Two Blocks Long N automobile spring forty-five feet long is used by a Seattle factory as an advertising sign. It is built of the same materials as an ordinary spring, and the workmanship is as accurate as in a sprig of the usual size. If put to actual use the spring shown would fitanau- tomobile more than two hun- dred feet long seven-league boots.”’ Leave the Gathering of Mushrooms to an Expert Who Knows Them CCORDING to specialists in the United States Department of Agri- culture, there is no simple and infallible test for distinguishing between edible and poisonous mushrooms. The only safe mush- rooms to eat are those that have been gathered by a collector who knows his business. The most common edible densest i is the Agaricus campestris. Its cap is fleshy and hemispherical at first but later becomes expanded and nearly flat. It is smooth and light brown or white in color. The gills are white at first, later pink, and finally a blackish-brown. The stem is stout, smooth and furnished with a ring. It is readily recognized; but before the gills turn color it might be confused with the € Amanita, a poisonous variety. The gills of the Amanita remain white. The safe rule is to gather and would sup- port a weight A spring big enough to support the combined weight of ten pleasure cars is used as an advertising sign by a Seattle factory only those with — colored gills. Popular Science Monthly _ Clang!. The first aerial fire-fighting company in the’ world. The equipment consists mainly of chemical extinguishers. Clang! The Fire-Chief Is Coming in His Airplane HE fire department chiefs of every city of this country have their eyes on Chief Louis Almgren, of the San Diego, California, fire department. Chief Almgren has discarded the horse and buggy and the automobile and now races through the air in an airplane when chasing fires. When a fire box is pulled in an outlying section, the chief jumps into his flying machine and is at the scene of the blaze before the horse-drawn equipment gets around the first corner or the fire boat is going full steam ahead. His is the first aerial fire-fighting company in the world. In test flights made with the new air- plane, which is a one-hundred horsepower machine of the hydro- plane type, trips that ordinarily took the fire boats from twenty to thirty minutes to make were made by airplane in from two to five minutes, counting the necessary time in getting the engine started. The device for sup- porting the arch and removing callous spots Extinguishing bombs are suggested for forest fires You Will Never Be Efficient While Your Feet Hurt You CCORDING to some of our best physi- cians many of our bodily ills are di- rectly attributable to improperly-cared-for feet. This does not refer particularly to fashionable footgear, but rather to fallen arches, which are more common than is ‘ realized, and to the painful callous ‘spots which prevent comfort in shoes of almost any make. An adjustable device for sup- porting the arch of the foot and for removing such callouses on the sole is shown in the accompanying photograph. It consists of a num- ber of supports which can be placed in any desired position and adjusted as needed from time to time. To remove callouses, rubber inserts in a pocket are placed un- der and around the affected spot. There are no metal parts, the material used being soft flexible leather and rubber. The cure is not an overnight one, but the relief is said to be immediate. Those of us interested in science, engineering, invention, form a kind of guild. We should help one another. willing to answer questions. The editor of The POPULAR SCIENCE MONTHLY is J } 7 ig ba en The bomb is six feet six inches long. The diam- _ eter of the head is six inches The Ideal Aerial Bomb It explodes six feet above the ground regard- less of the height from which it is dropped N aerial bomb which explodes about six feet above the ground, re- gardless of the height from which it is dropped, has been tested out by the Ord- nance Department and probably will be manu- factured in large num- bers. It is the inven- tion of Lester P. Bar- low, a former coal passer in the United States Navy who later joined Villa’s forces in Mexico and was at the head of railroad shops where the rebel chief had his artillery ammu- nition made. While there he conceived the idea and partially perfected the device. The novel feature of the bomb is that it explodes before it hits the ground, whether it is dropped from a height of two thousand feet or twenty thousand feet. The difficulty with bombs used in the past is that they have been fired by contact with the ground, burying them- selves in the earth before exploding. Thus ninety per cent of the force of a bomb dropped on ordinary ground is ex- pended against earth, instead of scattering its fragments over a wide area above ground. Inventors have been aware of this- deficiency of the tear- shaped bomb for a_ long time. The idea upper- most in their minds has been to develop a bomb that would explode head high and whose bursting fragments would cover a wide circle before reach- ing the ground. So far as is known no foreign coun- try has such a bomb in its possession. The bomb which comes closest to realizing the maximum of efficiency, as the Ordnance Department interprets that term, is this bomb devised. by Mr. Barlow. The above-ground ex- plosion is made possible by a rod that protrudes from the point of the bomb after it has been dropped from the aircraft carrying it. This The detonating rod sets off the detonator as soon as its point touchesthe earth is about six and one-half feet long. As soon as its point touches the earth it sets into operation a detonator containing about two hundred grains of fulminate of mercury which immediately sets off the explosive. ‘ | Ng The fin-like device at the top of each bomb is a stabil- izer which keeps it true to its course during its flight 586 The bomb weighs about one hundred pounds. It contains about forty pounds of trinitrotoluol and the steel casing and other metal parts of the bomb, which are blown in- to fragments by the explo- sion, have a total weight of about sixty pounds. The bombs can be manufac- tured at a cost of about apparatus cal position. - Having Popular Science Monthly | fifty dollars each exclusive of labor cost. The bomb is about six feet six inches long and the diameter of the war head is about six inches. At its upper end there is a stabilizer which keeps it true to its course. The bomb is carried suspended in a horizon- tal position beneath the aircraft. When released, the end containing the explosive, being the 387 submarines. For this kind of work the nose of the bomb is made to operate if it strikes a hard substance and not to operate if it hits water. In the tail of the device is a timing mechanism that can be set to let it go to any depth below -the surface of the water’ before it explodes. Should it hit any solid object on or below the top of heaviest, drops first, bringing the into a verti- assumed this position, the action of the air operates a valve which re- leases a tele- scoped tube to which the stabilizer is attached. This extends the device to a full length of about ten. and one-half the water it will explode instantly, but if it con- tinues going down through the water, when it reaches the depth for which it is: “Bets. 1t will explode automatical- ly at that depth just as if it were on land. In this way it be- comes the most threat- ening men- ace to the feet. At the same time, the detonat- ing rod is re-- leased from its position in the center of the bomb until it protrudes a distance of about six feet six inches below the war head, ready to set off the detonator as soon as its point touches the earth. The manner in which the detonator operates and other features of the bomb are of great military value and are being kept a secret. It is known, however, that up until the time the bomb is dropped from the air- craft carrying it, the detonator is held in such a position that it is impossible to discharge it, so that no matter how much explosive is in the war head there is no danger. Only after the bomb starts on its way toward the earth does the detonator become operative. To demonstrate its safety features the bomb was riddled with rifle bullets during a test in England. It failed to explode. According to Representative Tilson of Connecticut, the Government is now de- veloping a bomb of this type to drop on Young girls as dental hygienists examining the teeth of several boys and girls in the Vanderbilt Clinic, New York city submarine yet devised. The Dental Hygienist Takes Her Place Beside the Dentist OMEN have assisted dentists for many years, but not until recently did it become necessary for a girl to attend a three months’ course of training and then pass an examination before she could take her place beside the dentist and help him with his work. The accompanying illustra- tion shows the graduating class of the Vanderbilt Clinic, in New York city, ex- amining and cleaning the teeth of several youthful patients. These girls study and do practical work in the laboratory for three months. After that they take an examination; if they pass it they are given the title of “‘dental hygienist.’’ A great deal of minor work is entrusted to them, such as treating gums, cleaning the teeth and administering gas. None but high school or college graduates are accepted for training. 388 Subduing the Cow’s Tail with a Simple Wire-Clip Device IGHT after night Popular Science Monthly Each pocket of the pool table is provided with a V-hinge baseplate at the top. Electric contacts are held on the ends of both of the halves of Arthur J. Thomp- son, of Argyle, Mich., was flogged by . cows’ tails. He milked two cows, which stood side by side. When milking the out- side cow he got but one tail in his face, but when he milked the inside cow he got the combined © swishes of both tails. Needless to say, this an- gered him. So thoroughly tail-flogged was he that he decided then and there to subdue the cow’s tail. Taking a piece of wire and a pair of pliers he worked for two hours on his subduer. His first model completed he tried - it-on the cow ‘‘and gota these baseplates. The contacts lead to dry bat- teries and an electromag- net in the spinning de- vice. Thus, when you succeed in starting a ball towards any pocket, the weight of the ball as it passes over the baseplate forces the hinge arms to- gether and closes the circuit. Instantly, the armature of the electro- magnet is sharply pulled down. By means of the ratchet-and-pawl ar- rangement at the end of this armature, the hand on the spinning device is set whirling around in front of the score dial. The number at which the _ crack on the head,” as he tells us in a letter. But he did not stop. He worked another two hours, improved his model, tried it on the cow for the second time and lo! it kept the tail where it The cow’s tail clip end of the U-shaped loop hand stops is the num- ber of points which your pocket scores. ‘While the number thus scored will depend solely on your luck, skill is always required to start the hand going. is fastened in the - belonged. Several months later the Government issued him a patent. His device is a simple U-shaped wire loop loosely fastened round the right leg of the cow, with the exterior side bent and twisted so as to form a clip to hold the tail. When placed in the clip end of the loop, the cow’s tail can not be moved, nor can. the Magnet in keeping the scor armature Pe c " without individual calculations. Ratchet Batteries cow kick with that foot. Combining Luck with Skill in a New Game of Pocket Billiards O win in the game of pocket billiards . devised by William Heffley, of Penn- sylvania, you will have to be lucky as well as skillful. His invention adds to the age- old game an electric spinning device which is operated by the ball entering into its pocket. The spinning device is likely to score you almost anything, so that a closely matched game can be made not only a matter of skill, but one which is in- tensely exciting. Heffley’s device can be attached to any pool table without altering its construction. Cue ball i pis The weight of a ball traveling towards any one of the pockets closes an electric circuit The device also aids — Popular Science Monthly Seventy thousand tons of ice, valued at $100,000, which, owing to the difficulty of handling, had to be left to-melt in the sun after fire had destroyed the buildings in which it was stored In an Encounter Between Fire and Ice, the Fire Won BOLT of lightning during a heavy rainstorm near Warnertown, Pa., re- cently, struck one of two huge icehouses. The resulting fire soon spread to the other icehouse, and in a short time even the inside partitions in the buildings were half burned out, surrounded with ice though ‘they were. “All that remained after the fire were two huge mountains of ice which, owing to insurance laws and other difficul- ties, were left to melt in the sun. Who Would Fear Bullets in an Armor Like This? HE United States is equipping I every soldier with an exact du- plicate of the British type helmet made of shrapnel-proof but not rifle-proof steel. This helmet weighs only two pounds, two ounces, and is considered by the “Government to be superior to the French and German hel- mets. In the opinion of the United States Government, the various types of helmets rank in the order of British, German, and French. Fhe German hel- met covers more of the head and is a better protection in that re- spect, but the Gernian shape helmet cannot be made of the high grade material of the British helmet. The French type helmet is inferior to the other two both in shape and in resistance to shrapnel bul- lets. The German helmet weighs considerably more than the British, which is a The steel helmets, body armor and necklets with which soldiers will be equipped for special work disadvantage considering all the other weight the soldier is required to carry. The minimum thickness of high grade steel which would resist rifle bullets is .15 of an inch. This is four times as thick as the present helmet steel, which is considered too thick for practical purposes. In addition to helmet protection, when especially difficult and hazardous operations over No Man’s Land are contemplated, the soldiers will be equipped with body armor. This body armor consists of slightly curved ~ steel plates sewed in a canvas sack, ex- tending down to the knees and protecting the soldier frém bursting shrapnel, but not from rifle or machine-gun bullets. This body armor, which weighs only sixteen pounds, three ounces, is strapped over the shoulders and around the body. Gas masks will of course be furnished for special operations, and eventually a limited quan- tity of necklets will be provided which are made up of twenty- four layers of Japanese silk which surround an inner lining of Japanese silk waste, the whole being encased in a canvas cover. This necklet protects the upper chest, the back of the head, and the sides of the face. Neither the necklet-nor the body armor will be furnished every soldier, but will be kept in store and supplied for espe- cially difficult work only. Heavier body armor, which would be proof against rifle bullets as well as shrapnel, has been tried by all the belligerent nations but so far has not been generally adopted because it ‘weighs fifty-five pounds. Popular Science Monthly College of Pennsylvania, who is a specialist in agri- culture. Between lectures the student has the benefit of an additional correspond- ence course on the same subject. But the most appreciated part of this undertaking in the neces- sarily monotonous lives of the prisoners is the practical demonstration of the course, as shown in the roof garden. Robust radishes, crisp lettuce, the bountiful bean and other vegetables in common usage are planted and flourish under the sci- entific cultivation and lend Under an agricultural expert the prisoners of a Philadelphia interest and variety to the prison bill-of-fare. penitentiary are planting vegetables on the prison roof A Penitentiary Roof Garden—An Example of Scientific Farming HE very flourishing roof garden shown above is not over the top floor of any gilded hotel, or millionaires’ club. It-sur- mounts a very different kind of hostelry— the Eastern Penitentiary, in Philadelphia. There the convicts are cultivating what might be called, according to the times, a “‘war garden”’; but as far as the men them- selves are concerned, the open air occupation and the pride in their fine crops afford the prison- ers such real satisfac- tion, akin to pleasure, that the place seems in itself a peace garden. The men are not chosen and sent to this work. Of his own volition any of these future scientific farmers may make application for en- rollment in the class of agriculture which is taught in the peni- tentiary. Having been enrolled, the member of the class attends three lec- tures a week given at the prison by a pro- fessor of the State Making newspaper Cushee rolls the strips, ties each one securely and boils them in paraffin Newspaper. Torches to Take the Place of Candles if you want to do your bit toward making the world safe for democracy and don’t know how to do it, you might take up the work started by Mrs. Edward Cushee, of New York city. She is making torches for our troops who will soon hold a sec- tor of trenches in France. The torches are to take the place of candles, and they are made of old newspapers and par- affin. To make one torch she takes six strips of news- paper, two columns wide, and rolls them up, tying them _ securely with cord. After boil- ing each roll of paper in paraffin for twenty light. It will burn for forty-five minutes and give off a better light than the ordi- nary candle. In this “bit” of patriotic endeavor the boys and girls can also lend a hand —the boys to collect the old papers, and the girls to cut the paper into strips and roll them. candles. Mrs. minutes it is ready to: , — Paying 150 Per Cent _ FNTENT upon an increase in the egg and 4d poultry production in Texas, the de- partment of poultry husbandry in the State _ Agricultural and Mechan- ical College _has_ prepared a photograph _ which visual- izes for the E farmers, and the city man- Popular Science Monthly 391 French lines. They were notably success- ful, and attracted world-wide attention. Since that time numbers of trench-diggers have been employed on the battlefield, until now they are to be seen everywhere.. In an eight-hour day one digger can excavate trenches sufficient to hold an army of seven thousand men. It would take the seven thousand troops two days to dig the same length of trenches. Of q as well, the course, the dig- 4 wonde rful ger makes bet- 3 earning possi- —— ter progress bilities of the where the earth _ hen as an in- is free from _ dustrial ma- ae large stonesand chine. From seventy pounds of poultry food a good hen will produce obstructions. =f about one hundred and fifty eggs in the course of a year | Considered The accom- industrially, says the department, the hen is a very efficient machine. From seventy pounds of feed costing about three cents per pound, a good hen will produce in the course of a year from 150 to 160 eggs, which are worth just now about three or _ four cents each. An Army Burrows Itself in the Ground by Machinery ECHANICAL trench-diggers are not ; new, either in this country or in _ Europe. About two years ago the first machines to reach Europe were put to work excavating trenches behind the panying photograph shows a digger of the kind generally used. Steel buckets at- ° tached to an endless chain dig the dirt and carry it up a side-chute where the dirt is dumped. The matting of leaves and bran- ches which covers the machine is put there to deceive enemy airmen. Checking Insect Ravages with Armies of Enemy Insects NE hundred million dollars are lost to the United States every year due to the ravages of insects in crops. Half these insects were imported. Though insecticides are useful, they are not effective under all con- ditions. The most satisfac- tory results have been ob- tained by introducing other insects which feed upon the undesirable foreign pests. The threatened destruc- tion of California’s orange groves was arrested by the importation from Australia of a certain species of lady- bird. The tiny workers were shipped in tin boxes, placed on ice. Once released in the atmosphere of southern Cali- fornia, they set about their appointed duty with such avidity and multiplied so rapidly that the pests were . A modern trench-digging machine excavating a trench on ee The machine top is decorated with camouflage French soil. virtually wiped out in a very short time. 392 | ! Popular Science Monthly Testing the hearing of a soldier with the aid of a machine which regulates the length of sound waves Buy Good Meat and Chop It Yourself eee series of investiga- tions of ten samples each of Hamburger steak, made by the Department of Agriculture, revealed the fact that six samples of the first and five of the second series yielded counts of more than ten million microbes per gram. A great many differ- ent kinds of bacteria were found and the conclusion was reached that a large amount of Hamburger steak sold in the marketis unfit for food. The Department ad- vises that the housewife buy good cuts and chop it herself. Deafened by Shell Fire, but Cured Anchoring the Fisherman to the by a New Sound Machine Fishing Pier | HEN the big guns fire, not only are FTER several fishermen had been men before it killed, but hundreds of pulled off the Redondo Beach pier, those behind it lose their hearing, due to the near Los Angeles, California, by large fish, terrific noise of the explosion. The roar of _ the city built a new pier with special pro- a barrage fire is like a million boiler visions for keeping fishermen anchored to it factories plus a hundred thousand pneu- so that ‘‘the biggest fish that ever was matic riveters. Little caught”’ will no longer wonder is it that the ears can not with- stand the noise. In Europe are thou- sands of shell-deafen- ed soldiers. In the accompanying .photo- graph a soldier is shown facing an ap- paratus for graduat- ing and applying the sound waves. With the aid of this ma- chine the nurse is able to know just how deaf her patient is and to what sounds he re- sponds most quickly. It is.a slow and pains- taking method of treatment, but it has resulted in a number of cured cases. In fact, the deaf- ness resulting from be able to get away with bait, hook and line as has so often: happened in the past. The pier is con- structed of reinforced concrete. Around-its - for the fishermen, and a concrete rim on the foot rest enables the men to hook their boot heels over. it while fishing. Fish weighing as much as two hundred and ninety pounds have been caught from this pier even before it was made safe for the fishermen. The big fish haven't called that way lately. But when they do they will find the the battle noises is, in A fishing pier with a seat and the majority of cases, a foot rest to prevent the men only temporary. | from being pulled overboard fishermen anchored to their posts, ready to pull them on land. outer edge is a seat. ~ ness. So Ralph secured an old 4 4 F b | Paddle Your Own Canoe—But Do It Mechanically ENICE, in California, gets its name from its resemblance to Venice in Italy. Its streets are canals, and everybody travels about in boats. Ralph Johnson, a thirteéen-year-old resident of the town, had a “‘cranky”’ little canoe that he built at home in his base- ment workshop. The craft is but ten feet in length, but wielding a paddle is slow, back-breaking, laborious busi- bicycle rear hub and con- verted it into a neat four- bladed paddle-wheel. The wheel was then mounted on wooden forks, and securely bolted over the rear deck of the canoe. Three bicycle chains were stretched be- tween the sprocket of the Popular Science Monthly 393 ~¥P—Fye for peri- A scope attach paddle-wheel and a bicycle- = singe x } ment crank hanger mounted in the. A bloody finish with the revolver machine- aK Magazine guns. At right: Detail of the attachment holder cockpit athwart the gunwales. The pedal was removed from the crank-hanger and a handle substituted. The tiny crait was also fitted with a rudder, which, by wire controls, is operated from left to right by the forward or backward movement of a lever convenient to the lad’s left hand. Instead of bending over a paddle, Ralph now cruises about, turning the crank in the cockpit of his boat as easily as he would operate a hand organ. With his left hand he steers with the rudder. Instead of laboring along at four miles an_ hour, he now travels at the rate of eight miles an hour with less effort. Loaded \— magazines Close-up Fighting with the Revolver Machine-Gun N Englishman, Charles J. Cooke, has invented a new magazine attachment for the auto- matic revolver. The attachment is simply a holder which enables a number of stored maga- zines to be fed into the revolver as fast as they are needed. Stch an ‘‘auto- -matic’’ as the Colt .45 is pushed into the saddle on the upper end of the holder. When the eight shots have been fired, the usual ejecting spring is pressed; the empty maga- zine drops from the gun down into the slot in the ‘holder, and is ejected. In- stantly, one of the full magazines held in readiness in the bottom of the holder is pushed up into place. When this magazine is ex- hausted, the two others can be fed into the hollow end of the revolver. A bayonet is placed on the lowef end for hand-to-hand fighting. The length of such an at- Ralph propels his boat by turning a crank in the cockpit. With his left hand he keeps the boat on its course tachment would be slightly over twelve inches. 394 A Heel Which Will Wear Evenly All Around INE hundred and ninety-nine persons out of a thousand wear down the heels of their shoes at the sides. The result—weak ankles and a crooked and slothful step. It took a real genius to think of the clever method of correcting this which is illustrated in the accompanying photograph. The rotating heel! All you need do when your heel becomes side-worn is to turn it around and let the heeft wear down on the side opposite! But don’t wait until it is very lopsided. A short but heavy bolt, screwing through thread- ed plates into the heel Popular Science Monthly Va a bs ’ No wonder, then, that a new type of car — has been designed to meet the requirements of transportation and weather eonditions, which promises to eliminate much of the loss now incurred. This new type of car is a combination refrigerator and ventilator. In construction it is the same as any ordinary refrigerator car, except that in it a_live-air space is provided at the sides, ends, floor and ceiling. By means of this live-air space a wall of refrigerated air completely surrounds the interior of the car. The ice box is located in the center of the car directly under the roof, instead of in the ends of the car, which makes it possible to carry twenty per cent more and into the shoe, holds the heel firmly on. If your heel becomes too much worn on one side, just turn it around and wear it down on the other to keep an even surface freight. It has three open- ings into the car, one at each end and one in the center. At Last! A Refrigerator Car That Really Works ERE it not for refrigerator cars, we could not tickle our palates with out-of-season delicacies and would have to satisfy ourselves with the fruit and vege- tables that grow in our own particular sec- tions of the country, leaving California fruits for the Californians and Florida products for the southerners. And yet the producers and wholesalers claim that re- frigerator cars are not at all what they ought to be. The warm air enters the ice chamber through a netting at the end of the chamber. been cooled by passing over the ice it passes downward through the opening in the center of the ice chamber into the car. Entering the cen- ter opening, the cold air falls to the floor and is spread out over the car towards each end. The warm air rises and enters the ice box through a netting at the end, where it is cooled and again passes through the opening in the center of the ice box into the car chamber. The cold air is also drawn into the live-air space through the opening in the sides and ends of the car by the rising warm air which passes through this space to the ice box, where it is again cooled and discharged through the middle opening of the ice box. This has a drying effect and gives the proper refrigeration. . After it has As it gradually loses its cold it rises to the top again How the U-Boats Get Through the Nets They are equipped with remarkable motor-driven circular knives and with steel flanges that spread out like doors us from Europe we learn that Germany has equipped some of her U- boats with ingenious devices - to enable them to cut their way through submarine nets. One boat with a double _ flange of thin sheet steel pro- truding from both sides of the bow is said to have been destroyed by shell fire and _the device itself, practically intact, is said to be in the hands of the British Ad- miralty. A second boat, equipped with heavy motor- driven circular knives at- ae reports that reach Rotary circular knives on flexible shaft tached to steel hawsers, tor- | > ee : Flexible shaft Gear core of flexible peek. shaft pedoed a merchantman, and the captain, while in a small boat, made a drawing of the device for the Admiralty. The accompanying illustration gives a clear idea of these net-cutters. The double flangg of thin sheet steel which protrudes from both sides of the bow of the subma- rine is, operated by electrically-controlled gears. The flanges spread on either side of the bow to a distance of eighteen feet, or The net-cutting device consists of heavy circular knives attached to steel haws:rs extending from bow to stern thirty-six feet in all, whenever the nose of the vessel touches an obstruction. Their action is said to be automatic, although an operator within the boat can extend or withdraw the device at any time, by moving two heavy metal arms. : The U-boat equipped with the circular knives is obviously far bet- both sides Plan, view of. bow showing tlanges extended on ter able to cut its way through a net than the boat just described. It does not bother about a de- vice at the bow, figuring, no doubt, that the sharp nose of the vessel and its rounded hull are sufficient to get through a net or stop ‘the boat before it becomes entangled. . However, it does not permit its con- ning tower to go unpro- tected. Several strands of stout steel hawsers contain- ing motor-driven | knives, a foot in diameter and placed about a foot apart, are stretched from the bow through the conning tower to the stern. Striking a End view of double flange The double flanges of steel protruding from both sides of the bow are operated by electrically-controlled gears 395 net, the knives would re- volve on a flexible shaft. The Most Powerful Locomotive in the World It- weighs 260 tons; it is 76 feet long, and it takes cur- rent from a trolley .wire no bigger than a lead pencil By William H. Easton The power of this loco- motive is equal to that of one hundred trolley cars, or 14,000 horses, or 56,000 of the strong- est men. It consumes enough current to light over 200,000 25-watt electric lamps; and many a town of 25,000 inhabitants has an elec- tric plant of smaller capacity. This is be- cause high voltage is used in distributing the strong electric current A glance at the illustra- tion shows apparently eight driving wheels on each side, but there are actually only six. The wheels on each end are gears which are driven by the motors and which in turn drive the driving wheels throu the connecting rods. By this arrangement, the motors can be lo- cated up inthe caband - not down on the axles as in a trolley car HOUGH hardly more impressive in appearance than an ordinary bag- gage car, the electric locomotive illustrated has the distinction of being by far the most powerful thing on wheels. Exerting its maximum effort, it can develop 7,000 horsepower, which is fifty per cent more than its closest rival, also an electric, can do. It is not necessary for the entire main line of railroad to become congested be- fore trouble is experienced, for, since a passage is no wider than its narrowest point, one congested section sets the limit to the capacity of the whole. Such a section exists between Altoona and Johnstown, Pa., where the freight traffic is unusually heavy, amounting to 300,000 tons a day. Trains over this di- vision must push up steep grades, pass around the famous Horseshoe Curve, and run through a long tunnel. Though the railroad is not particularly embarrassed at present, it is taking no chances, and some time in the future its new huge elec- tric locomotive, with many more like it, up heavy stresses. It Rides Easier Than a Steam Locomotive Each gear wheel carries a set of coiled springs. The reason for these springs is as follows: engine starts, the piston does not move with a sud- den blow, because there is a cushion of steam behind it which is compressed and eases the shock. But a motor, in endeavoring to start a heavy train through a solid gear train, strikes its gears sharply and thus sets By the use of these springs, a cush- ion is introduced between motor and driving wheels will be handlimg the traffic through this “neck of the-bottle,”’ as such a section is graphically called. Trains so long that three of the largest steam locomotives can barely move them will be rushed up the grades by two electric locomotives at twenty miles an hour. In this way the capacity of the division will be more than doubled and all danger of congestion here will be removed for many years to come. One peculiarity of the electric locomo- tive is that its speed of twenty miles an hour cannot be exceeded whether running on electric power or coasting down hill. In the latter case the motors act as generators and return current to the line, and since power is required to generate current, a most effective braking action results which prevents runaways. At the same time the coasting speed can be regulated by the controllers, just as is the speed under power. Air brakes are therefore not need- — ed while coasting and are simply held for ~ emergency use: and for bringing the train - to a full stop. hen a steam 396 Popular Science Monthly _ The Candle Still Flour- ¢ ishes Even in This Electric Age i OWADAYS we think of light in terms of electricity or gas lamps, but it will surprise some to learn that the average daily expenditure for can- dies in this country alone this year will be about sixty-seven thousand dol- lars. On this scale the val- uation of the 1917 produc- tion of candlesin the United States will total a round twenty million dollars. A Patriotic Float Made of Raisins to Represent a ‘*Tank’’ RESNO, which is the center of the California raisin industry, each year in May holds.a “Raisin Day” celebration, an important feature of which is a parade. This year it was given over to a patriotic display and many remarkable floats moved in the procession. The float which won first prize as an industrial display was entered by one of the express companies. It was made up as a “‘tank,”’ twenty feet long, fourteen feet wide and thirteen feet high. The float was built up solid with raisins. Out‘of the float projected the muzzles of fifteen dummy cannon. On top was a miniature refrigera- tor.car. The float was drawn by four bay horses and This crane, attached to an idle dirt wagon and operated by a crank, will pick up and empty the largest garbage cans Converting the Dirt Wagon Into an Efficient Garbage Collector ILLIAM M. WALSH, a highway commissioner at Grand Rapids, Michigan, holds the. patents on a novel scheme which enables him to convert any of the city’s idle dirt wagons into a more- than-ordinarily efficient garbage collector. His idea involves the use of a small crane by means of which the driver can lift the largest garbage cans into his wagon with little effort. The movable crane is secured against the driver’s seat and carries two tongs for grappling the garbage can. By turning a crank while standing on the ground, the two tong cables are wound. upon a drum, and the can is slowly lifted. On reaching the top of driven by : ‘*t¥Fn cle E and fifty pounds the crane, the driver fastens his crank upon another shaft which operates the ofraisins cable con- were re- necting quired for with the the body bottom of alone. The the garbage bottom of can. Turn- the float was ing this covered shaft tilts with huckle- the can up- berry greens The float was built up solid with raisins—just raisins. The - ward pee s bottom was covered with huckleberry greens and poppics bagel Marae and poppies. empties it. All the specialized knowledge and information of the editorial staff of the Popular Science Monthly is at your disposal. Write to the editor if you think he can help you. Do It with Tools and Machinery ieldidaicijutaeCEe, Wty Ly “a bbs dddg LUMI a hdd dddidddddidddcdddididibedusubddicduseibsissididien uses A radius gage 5 for measuring the concave and convex surfaces of tools and dies. Instead of having small.leaves it has eight small blades — Lae A brick and concrete drill A lock washer which over- An attachment for re- made of a steel tube or comes the loosening of grinding thread - cutting segment of pipe. It is cut nuts by vibration. It is dies of button type or lap- off at an angle, as shown made in hexagon shape ping out holes in punches MM / didi ME cddiddccccc. , ; oe gee SASS SSS SS y 4 A new joist lifter. The fisnifle® is Daniel Boone up to date. When the fire raised until the dog engages the tooth will not start use the automobile pump 398 SSS \) 4 ¥ Ls a Mase A hammer with removable faces of any desired size or shape, of steel, copper or other soft metal to_ suit different work 2 Abc A tackle for unloading automobiles. Sr eel — . So SSSuass | : Do It with Tools and Machinery The same ham- mérvat -Teft with a steel face for ordinary work requiring heavy pounding. Other faces may be substituted cdi Se The ropes are adjusted so as to lift vertically on each of the four wheels. The main member is a scantling suspended lengthwise of the automobile ae es i lt tie A boiler ther- mostat for indi- cating heat in chemical vats. A rod _ extending the length of the outer shell supports the bimetallic strip Above: A new valve grinder designed for engines equip- ped with valve caps A quick-action chuck with which a rotative tool can be re- moved and an- other inserted while the ma- chine spindle is revolving Above: A nut lock which prevents a nut from backing off from a bolt In center: A new machine used in post- cffices for tying envelopes into packages. 399 It ties from twenty-five to thirty bundles a minute with a non-slip knot 400 Rock-a-Bye Baby—In Your Self- Operated Cradle HELDON D. Vanderburgh, of Hastings-on- Hudson, New York, has a baby. . The baby wouldn’t go to sleep, and it was a thirty-eight-pound baby, too. The mother and father tried both crib and go-cart, but the baby wouldn’t stay in them. It was: im- possible for the mother to rock it to sleep. She was too busy. What was. to be done? Invent a new cradle, of course. Mr. Vanderburgh . decided upon a cra- dle hammock. He fastened the netting to end pieces to keep the cradle in shape and then suspended it from a shaft by means of two side arms. With. the shaft journaled to vertical standards he had a safe and sane cradle which could be opened, basket- fashion, to receive bedding and baby and then closed down securely. satisfied with rocking the cradle back and forth. Then the idea struck him that a clock-spring motor could do the same thing. Accordingly, he mounted a motor on a It operates a rod which in turn rotates a crank arm attached to the shaft. This imparts a steady but very gentle rocking motion. to The ticking of the clock also helps in lulling the child to sleep. standard. the cradle. wound up the mech- anism will rock for two hours without further attention; at the end of which! NX time the nap. will - probably be over and both baby and moth- er in good humor. Popular Science Monthly The automatic cradle, made of hammock net, is rocked by the aid of a clock-spring motor which imparts to it a gentle, steady swing At first he was motor power. When This rotating buffing wheel will press back the cuticle and polish your nails for you Even the Animals in the Zon Feel the Effects of the War HE war has laid a heavy hand upon the animals in the London Zoo. The places of those that have died have not been filled and many not-so- rare specimens have been killed off to save the cost of feeding and caring for them. Beef, fresh eggs, bananas, potatoes - and wheat have been eliminated :from the food list and the ani- mals have to sub- sist on substitutes. Chinese pickled eggs - are used instead of fresh eggs, and bread for the monkeys is made from flour re- jected by the Board of Trade. Occasion- ally fish is doled out, but it is only such as has been pro- nounced unfit for hu- man consumption. And Now It’s the Electric Manicurist : to Keep Your Nails in Order OHN W. RUGGABER, of Racine, Wis- consin, thinks the electrical manicuring machine he has just invented will soon be taking its place in every home. It is a small buffing wheel rotated by After softening up the cuticle in warm water, you simply push it back by pressing it against the edge of the rotating cushion. cious use of nail paste (please don’t use too much, we don’t like nails too highly pol- ished), Then, after a judi- | the center of the buffing wheel will shine up your nails as well as any mani- curist could do it, and doubtless in much less time and at much less cost. Popular Sctenee~ Monthly —~ ye 2 ies 401 A Scientific Laboratory Two Miles in the Air 2. th he pe, closing of _the little meteoro- ‘sity “once Pmtuinitained at the top of El ti, Peru, and the destruction by Alpine stounas: (perhaps aided by an earthquake) “ef Jamssen’s famous solar observatory at the summit of Mont Blanc, the loftiest scientific establishment in the world is probably the observatory on Monte Rosa, the second highest summit of the Alps, 14,960 feet above sea-level. The Monte Rosa observatory is also known as the Regina Margherita Cabin. It is really an outpost of a much larger establishment, situated at a lower altitude on the same mountain (at the Col d’Olen), and both institutions are called officially the Angelo Mosso Scientific Laboratories. They are maintained by international co- operation, each cooperating country being entitled to keep one investigator at the laboratories for every 5,000 francs con- tributed to the joint fund. To reach the Col d’Olen entails a ride of several hours on horseback or muleback; while the ascent to the observatory is a mountaineering feat. The higher station is habitable for only about two months in the year—from July to September. Every summer a temporary” telephone line—the highest in the world—is laid to the summit. Its construction and main- tenance require great skill and courage. Many of the poles are set up:in the shifting ice and snow of the glaciers. The tiie ss on Monte Tees. the second ae = summit of the rae is the loftiest scientific establishment in the world, being nearly 15,000 feet above sea level Khaki Has Been Used for Uniforms Since 1848 HAT is the origin of khaki? To whom are we indebted for it? It was first adopted in British India, in 1848, by Sir Harry Burnett Lumsden, who had been asked to equip a corps of guides to collect intelligence and to conduct an English force on the northwestern frontier of India. The cloth used was a‘ light cotton drill, as suited the climate of Hin- dustan, and took its name from a native term, ‘‘khaki,’’ which means in the Urdu language, ‘‘dusty,’” being derived from “khak”’ or dust. Thus the term applied to the color of the cloth rather than to the material. Though the dictionary tells us it is pronounced kaykee by the natives, the English have given it to us as kharkee, and this is the correct pronunciation. Having been approved, the use of the cloth spread from the guides to others in the Indian army, and it was worn in the Sepoy Mutiny of 1857 by the English troops. In the Boer War, 1899—1902, khaki was adopted in the British service for an active service uniform, and so worn by all English and colonial troops in Africa. But as cotton was not warm enough for the African highlanders, uniforms of the same kind were made of serge, and the term khaki thus included woolen as well as cotton fabrics. Because it was well fitted for the climate of Cuba and the Philippines, the United States chose khaki for the soldiers’ uniforms during the Spanish- American War. All Around ‘A Battleship: Corps. AN DLUB- S BER—Is this the largest ship in the Navy? MA J 0°8 Evans— Yes, the Arizona and her sister ship, the Penn- sylvania, are the largest. in commission. She is six hundred feet long, with a ninety- seven-foot beam, draws thirty feet, and displaces thirty-one thousand four hundred tons. Her speed is twenty-one knots, or twenty-four miles an hour, and her final cost thirteen million, six hundred and ninety-five thousand dollars. LANDLUBBER—And she has the biggest guns? Major Evans—Yes, each of her twelve fourteen-inch or turret guns weighs sixty- four tons, and is fifty-two feet long. The shell weighs fourteen hundred pounds and the powder charge three hundred and eighty pounds. It costs a little more than five hundred dollars to fire each gun, and to make it possible to fire that gun cost the government eight hundred and fifteen dollars for each pound of her broadside. The turrets are placed on the ship’s center- line, with the three guns of each after turret arranged on a line above those of each forward turret. Here we have the heaviest broadside and greatest radius of fire possible. When all three guns in a turret are fired together in a salvo the two outer guns are fired simultaneously and the fraction of a second before the center gun. If all three were fired simultaneously the terrific blast would derange the flight of the shells. LANDLUBBER — How are the turrets moved? Major Evans—Turning engines or mo+ tors move them on rollers lying in a circular path. T.R. Timby invented the revolving Major Frank E. Evans, who takes you around the battleship A Landlubber’s Questions — Answered by Major Frank E. Evans, U. S. Marine Corps And so you would like to see a battleship? Let us in- troduce you to Major Frank E. Evans of the U. S. Marine He will take you all around the ship and, short of actually firing the big guns, will show you everything. Don’t be afraid to ask questions. The Major is used to landlubbers turret in 1841 and Ericsson paid him five ie pti dollars royalty on each turret he ult. LANDLUBBER—How thick is the armor on this ship? Major Evans—It varies from nine to eighteen inches on the triple turrets. The barbette armor is thirteen inches thick. An armor belt protecting the engines and magazines covers nearly three-quarters the length by a belt thirteen and one-half inches thick, seventeen inches from top to bottom and running half below load water line and half above. On the conning tower thé sixteen-inch armored sides and the five to eight-inch armor protecting the broadside guns brings the weight of armor up to one- fourth the ship’s entire weight. LANDLUBBER— Why isn’t this deck anadé of steel too? Major Evans—It is. There is steel be- neath the teak covering of three and one- half inches on which you. are standing. Without the wooden covering a steel deck | would be unbearable in the tropics. We use teak now in place of yellow pine. It costs more but does not spread and that does away with constant calking of seams. One deck below is the protective deck of from two to five inches of nickel steel armor. 2 2 LANDLUBBER— And the decks below? Are they built in the same way? On ea we ‘ipaile, lad ‘Go time to do his own ‘sewing and mending 402 On Board a United States Super-Dreadnought Above: A two- gun turret. The five-pointed star plugs in the guns are called tom- pions. They keep out the spray In circle: Bring- ing fourteen- inch shells on beard the New York. Each shell weighs fourteen hundred pounds Above: Signaling on the bridge of the North Dakota. The semaphore is making the letter “U.’’ Signalmen are Wwig-wagging and hauling down flags At left: The military or fire-control mast is made of steel tubing so that one successful shot can not carry it away. Notice the searchlight platform 404 Major Evans—They have heavy lino- leum coverings. When we go below you'll notice. two curious things: rough paint on the bulkheads and magazines and gaily striped bands on piping wherever _ we go. LANDLUBBER—What’s the reason? Major Evans—The rough paint is broken cork mixed in a sticky paint. The cork prevents the steel from “‘sweat- ing’”’ and helps keep Popular Science Monthly officers. A flagship would have ten or twelve more officers. Each ship has its captain, executive, gunnery, navigating, engineer, first lieutenant, medical, pay and marine officers. Most of these have one or more assistants. The size of the crew is based on the number needed to fight, navi- gate, keep the ship at full speed through a protracted battle, feed the crew, attend the wounded, fight fires, make repairs and keep the fire control the magazines and ammunition pas- sages at a more nor- mal temperature. The piping has the colored bands so that the leads of the piping can be fol- lowed to expedite repairs. Steam has a black and white band, salt-water green and black; fresh water is lead and black; and ven- tilation piping has yellow and black. LANDLUBBER— What are those plugs in the ends of the guns with the five-pointed stars in the center? and communications going. . LANDLUBBER— When a ship goes into battle does she carry her boats to take off the crew in case she is sunk? Major Evans— When. a ship leaves port -for impending battle she is stripped of most of her boats. The ones left on deck and lashed with canvas to keep down splinters... All wooden. gear except the mess tables and benches are re- moved, and they go . overboard before the Major Evans Tompions. They keep spray from dashing into the muzzles and rusting the bores. LANDLUBBER—What other guns does she carry? Major Evans—Twenty five-inch guns on the broadsides for defense against tor- pedo attacks at night; four semi-automatic three-inch anti-aircraft or ‘‘sky’’ guns mounted on special platforms; four six- pounder saluting guns amidships and three- inch field pieces for landing purposes. There are only three kinds of guns in the Navy: the turret guns running from eight to fourteen inches; the intermediates running from four to seven inches; and the smalier or secondary guns running from three inches down to automatics that fire rifle ammunition. LANDLUBBER—How many officers and men would be on board in a battle? Major Evans—lIn round numbers, one thousand, of whom about forty would be The sailor’s private wardrobe is a canvas bag which is cleaned and inspected every few days fighting begins. All inflammable or splinter- producing equipment is either stored ashore or throwr overboard except the mattresses of the sick bay. Stanchions and davits are stowed, and the life lines on deck are removed. In battle practice all these articles are either marked ‘‘store’’ or ‘“‘overboard.” LANDLUBBER—But what becomes of the crew with so few boats available? Major Evans—If the ship sinks they trust to life preservers, wreckage and rescue by other ships. Otherwise it’s Davy Jones’ locker. LANDLUBBER—Where does the crew live? Major Evans—On the two decks below. The compartment in which a man slings his hammock is his home. Here he keeps his sea bag, ditty-box, and rifle. He eats there and is stationed at the compartment’s gun. When not at mess the tables and benches are slung up above. The Government sup- plies an excellent ration, and the officers pay for all their food and. other supplies. ’ aa a a < board are stowed on . : em) electrician. Popular Science. Monthly The turrets are rotated by turning engines or motors which move them on rollers lying in a circular path. The revolving turret was invented in 1841 Some ships have electrical galleys in which the cooking, dishwashing, paring of pota- toes and practically all work is done by electricity. The chief cook is an expert On the Arizona they find oil- burning galleys more economical. LANDLUBBER—What advantages has the oil-fuel ships over the.coal-burning? Major Evans—tThe space formerly re- quired for coal bunkers is now available for greater crew space. The oil-burners: are more flexible of control in increasing or reducing speed and are practically smoke- Jess. The crew is free from the bugbear of coaling ship. This ship carries twenty- three hundred tons of oil fuel. LANDLUBBER—You mentioned the ma- rines. What do they do? Major Evans—Originally marines were employed aboard men-of-war to put down mutinies. Today their duties are almost identical with those of the bluejacket’s. For all landing parties the marines, being trained soldiers as well, “hit the beach”’ first. In battle they’ man the torpedo defense guns, help supply ammunition to the turret guns and do other duties. Those not with the fleet either guard our Navy yards or are held in battalions or regiments for expeditionary service. Each battleship has a captain and lieutenant of marines and accommodates about seventy-five marines. LANDLUBBER—I hope you don’t mind my asking why the trousers of a sailor flare out so at the bottom. Major EvAns—That’s a sensible query. With the “‘bell’”’ or “‘spring’’ bottom he can easily roll his trousers above his knees when washing decks. The three narrow white stripes on his collar are inherited from the stripes worn by the British blue- jacket in commemoration of Nelson’s three great sea victories. The black kerchief is supposed to have been first worn as mourning at Nelson’s death. LANDLUBBER—Where is the captain stationed in battle? Major Evans—The conning tower is his battle station. A complete steering and communication system is contained in its 16-inch walls, and armored tubes also con- nect it with the protective deck to prevent these systems from being crippled in action. LANDLUBBER—What do you call this mast that looks like a waste basket upside down? Major Evans—The military or fire- control mast. It is made of steel tubing so that one successful shot cannot carry it away like the old solid mast.. It carries the fire control communications and. signals, and the wireless. © Brown and Dawson The tree cricket makes its music by rasping its wings one over the other about seventy times a minute The Incessant Night Song of the Snowy Tree Cricket ROM early sum- mer to the time of frost, we hear a cheery, insistent night song that everybody knows. But only ‘persistent and careful students become’ familiar with the insect that trills the song. From the grasses, trees and shrubs comes this incessant music, represented by Vernon L. Kel- logg in the letters: “T-r-r—t-e-e; t-r-r —r-e-e.”’ This is re- peated about seven- ty times a minute without pause or variation. Whenever a per- sistent student . of insects obtains one of these’ singing, or rather fiddling crea- Popular'S cience M onthly tures, everybody. exclaims in sur- prise, “‘Why, that is something I never saw before; I never knew there was such a thing in existence. Is it a new pest? Is it something to be dreaded ?”’ Instead of something to be dread- ed it is one of the nature lover’s de- lights. Such singing insects seem to fit harmoniously into a summer night, and when one’s temperament becomes attuned to the sounds there is no more charming, natural music in the world. The Japanese have the right point of view. They hold tea parties in the fields, and between their sips of tea and bits of conversa- tion they listen to the calls and songs of such insects. Every student of insects knows that the term “singing’’ is used figuratively. It might be more truly described as fiddling because it is made by rasping one wing over the other in a rapid movement. This is well shown in the accom- panying illustration. The dress of the natives of New Guinea consists principally of broad stripes of white paint and. necklaces of small. bones The Soldiers of New Guinea Do Not — Dress in Khaki HE natives of; New Guinea are still classed as savages, although many of them have comfortable homes, clustered into vil- lages. The dress of the males consists main- ly of necklaces made of human and pigs’ bones. The war- riors make them- selves fierce with broad dashes of white paint on their bronze bodies and on their clubs. The bracelets below the knees of the warrior on the right of the accompanying pho- tograph are strung with pigs’ bones, probably used as am- ulets, since the pig is much beloved. Popular Science Monthly Some of Our Lake Waters Are Noted for Their Chemical Wealth HERE are several lakes in the United States which contain so- dium carbonate, borax, potash and common table salt. The longer the war continues the more valuable these chemical bodies become. Perhaps the best known of these is Great Salt Lake, Utah’s ocean of salt. Others are Searles Lake, Owens Lake and Mono Lake, all in California. The origin of these lakes is doubtful. In some cases they are probably due to an arm of the ocean becoming land- locked. The most remarkable feature about them is the fact that they seem to be continuously. fed from subter- ranean sources, since they maintain a uniform amount of salt. California Has the Latest Thing in Tree-Trimming Ladders WEIRD-LOOKING tended it is thirty feet high. From this height the tree- trimmer is able to cut off branches that are ten feet higher by means of his tree-trimming snips. In the illustration he is shown on the fifth rung from the top, cutting off the un- sightly twigs. He could climb to the top rung of the lad- der without over- turning it. The ap- paratus is collapsible and when folded up it can be wheeled from tree to tree or from job to job. For transportation from one town to another the push-cart end of the device is fastened to an automobile or wagon, and the ladder is towed along with ease. There are few tree-tops, even in California, which it cannotreach. W.L.Geimer is the inventor. lapsible. tree-trimming ladder has made its appearance in Pasadena, California. When fully ex- The tree-trimming ladder .is col- It is thirty feet high Two freak faces executed by the world’s most original and diverting artist—Mother Nature Lo, the Poor Furniture Man—He Sees Faces in Walnut OTHER NATURE has tried her hand at making faces. She chose the wal- nut veneer of Indiana and this is the result—two faces which may be likened to anything from saints to devils. The fact that they are part of the walnut markings of the wood, fresh from the outdoor workshop, is what makes them unique. Of course an experi- enced painter could have made _ better looking faces than these on any kind of wood. But he couldn’t make them so you couldn’t wash or rub them off. The faces which Mother Nature has put into this walnut wood are there to stay, safe against even sandpaper and plane. Walnut veneer is gener- ally used as an orna- mental facing for inferior grades of wood. There are some people who could point with pride to faces in their dining tables, calling them lost Rubens cherubs. 408 Popular Science Monthly © Int, Film Serv. The force of the outrushing water turns the ten nozzles round A Fire-Hose with Ten Nozzles. - It’s to Be Used in Ships’ Holds IRE in the hold!” Since the first freighter sailed the seas, there never has been a warning more to be dreaded. A fierce fire cannot be smothered. There is nothing to be done but to take down the hose and face the music. In an effort to improve on the old and dangerous method of groping about in the dark and the smoke to, locate the seat of the fire, Fire Chief Heffer- nen, of New York, has been testing out a novel ‘system. He has been using a multiple nozzle which floods the hold in every direction. An entire cargo may thus be damaged, but after all, that is better than suffocating the firemen. . Not one, but ten ordinary nozzles ter- -minate at the end of a great hose. When they are lowered into the hatchway and the emergency engines pump away at full load, -ten great water streams rush equally out of each nozzle. In doing so, the nozzle mount- ing is turned around, so that no part of the hold is left untouched over a circular area a ‘hundred feet in diameter. About 16,000 gallons of water are pumped each minute. Cork floats keep the ring and platform afloat. right: Detail of the device At A Spring-Motor for the Human Jaw YOUNG girl was ad- mitted recently to a New York Hospital. She had a form of lockjaw. The surgeons removed the muscles of the lower jaw- bone and substituted a de- vice with a spring to be wound up just as one would wind up a clock. The de- vice was fastened to the jaw and extended over the head. The spring kept the jaw in constant motion. After about three weeks, the de- vice was removed. The muscles of the lower jaw had developed wonderfully. The girl was then put to chewing gum. The Story of a Life-Saving Platform —And How It Will Not Work! . INCE Germany began her submarine warfare, the number of applications for patents of life-saving apparatus has increased a dozenfold. Some of these have at least been reasonable, but most of them have been grotesque. Take, for instance, . a device invented by a citizen of Illinois. A man stands upon a wooden platform and straps to his shoulder a buoyant ring from which ee the platform is to be sus- pended when in the water. Unfortunately, however, ho instructions are given in the patent copy which would tell the man how he could jump away from the sinking ship. If a person is to stand upon _the platform, how is he to use his feet to jump? Even if a man could land in just the proper posi- tion in the water, this device, it seems to us, would be no better than the ordinary cork life-preservers. j\ Cork float. laf ‘Auxiliary float Py Wood atta rm Popular Science Monthly _A Waving Flag in Badge Form for Your Buttonhole NE of the novelties brought out by the war is a figure of Uncle Sam waving a small American flag above his top-hat. Owing to the construction of the badge, the flag actually moves, as in waving, at the slightest motion of the wearer. The badge consists of a _ metal figure of Uncle Sam, with the flag at the end of an up- raised arm, which isn’t an arm at all but a flexible spring fastened to the top of the shoulder of the figure, as the accompanying illustration shows. Each time the wearer of the flag moves, the spring 409 means of a chain from a scaffolding on wheels. The chain is attached to the ram at a point which will enable the operator to pick up the other end without much effort. That the ram is effective as a de- structive agent is manifest in the photograph. The side of the peasant’s cottage which lies in ruins was evidently of brick or masonry before the Germans de- cided to ram it to pieces. All that now remains of it is a few tottering beams support- ing a twisted and warped roof. The two wheels in front of the apparatus and the wire handles on the bottom pieces make the appar- atus a portable one. It jumps up and down and side- The flag is was probably moved from ways, giving the flag a waving orearh be place to place as the Ger- motion. By means of a stick pin on the back, the badge may be readily attached to the hat, coat, dress front, or even the neck-tie, wherever it is preferred. Demolishing French Cottages with a Battering Ram HE Germans have left behind them another tool of destruction during their so-called victorious retreat to the Hindenburg and Wotan lines. It is a battering ram such as Helen of Troy might have looked down upon from her father’s watchtower. But the Germans did not use it for destroying walls round fortified cities, as did the warring ancients. They used it for spring arm, as shown at the right mans retreated through a devastated and shell-torn country to the more for- midable positions in the rear. What Six Gallons of Good Gasoline Can Do EW persons have any conception of the immense amount of energy that is stored in the natural oil. products in everyday usage. Take, for instance, the gasoline that is used in automobiles day by day. The motorist will be interested to know that if the same amount of energy that is used up in “autoing” a hundred miles were employed to milk cows, some ten smashing in the sides of peas- ants’ cottages and reducing those structures to piles of debris. In the accom- panying photo- grapha French- man is illus- trating for civilization just how the ram was operated. thousand gal- lons of the milk could be obtained! Or, if the same energy were used in pattri- otic gardening, fully four acres of ground could be plowed. That amount of energy could also mix up eighteen hun- A heavy pole of sturdy wood is suspended by © Underwood and Underwood How the retreating Germans wrecked peasants’ cot- tages with an old-fashioned wooden battering ram dred cubic feet of the thickest cement. 410 Popular Science Monthly - Why Young Pheasants Re- quire Foster-Mothers N pheasant-raising the great- est difficulty is to secure “‘setters.”” Says L. S. Crandall in Pets, (Henry Holt & Co., New York), “If the female (pheasant) will incubate, she can not be excelled for rearing the young, but in most cases she refuses to perform this function. It is customary, therefore, to remove the eggs and place them under a domestic hen. For this purpose The kit preserves the shape of cigars, holds pipes up- right and provides a space for the storage of tobacco This Smoker’s Kit Is Approved by the Neat Housekeeper MOKING makes a contented man, it is said. On the other hand, smoking, if the pleasure be derived from pipes, is likely to make a very discon- tented housekeeper. For pipes have a careless way of spilling their ashy contents on tables if they are thoughtlessly placed on them. Joseph F. Jeckert, of Garfield, New Jersey, is therefore to be commended for his smoker’s kit. It not only keeps pipe ashes where they belong, but there are sini map orm for cigars, to- = bacco and matches in the same kit. The kit may be hung on a wall or placed on a table as it ap- pears in the photograph. The pipes are held in an upright posi- tion and if there are loose ashes they will fall out into the tray. Furthermore, the nicotin and other juices will run down the stems and into the bowls. A cor- rugated panel furnishes the up- right channels to hold the pipes. The pressure cylinder is suspended from a four- wheel carriage propelled by an endless chain a small bird should be chosen, preferably a Silkie, or a gentle little Bantam. A Novel Machine for Reclaiming Scrap Materials ERE is a machine which is interest- ing because of the many uses to whichitcan be put. It can be applied to general manufacturing and repair shop work where bent sheets and structural members have to be straightened or where it is desired to form new material to particular shapes. It is a press par- ticularly adapted to the straightening of bent railway truck-frames, center and side sills, side sheets, channels and truss rods. It is also used for the forming of new hopper sheets, as shown in the il- lustration, and the bending of guard rails and other work re- quired by way de- partments of rail- roads. The base of the press is a heavy flat steel casting, to which two up- rights are at- tached, whichsup- port a main cross- frame. Two channel sections placed back to back, constitute this cross- frame and serve as a track. Popular Science: Monthly Street-Cars Puil Each Other Up Hill in San Francisco N one of the residential sections of San Francisco is a hill so steep that an ordinary trolley car can not climb it. The chief engineer adopted a principle made familiar by many mountain rail- ways. A channel was cut between 411 This Device Won’t Let Your Hat Blow Off NEF hats have a way of blowing off their owners’ heads largely because no two heads are shaped exactly alike, and until the hat has been worn long enough to conform to its owner’s head it will not fit properly. A simple device the rails of each track from the base of the hill to the summit. In each channel was placed a heavy steel cable, which travels over a huge pulley at a point where the two Down hill has been invented to make any hat conform to the wearer’s head. It is an open-ended tube of cloth made of a single strip of material. The tube contains a strip of spring-steel, oneend of which is doubled back while the op- posite end extends beyond the cloth tube. When the device is in use this is inserted in the other end of the tube, thus closing the conformer in the hat. The metal strip has needle-like pro- tracks meet and become one at the summit. . : The car at the top of the hill and the car at the bottom each pick up the cable. © The car at the top of the hill is per- mitted to run under its own power down the slope, thus furnishing the energy necessary to pull the other car up the hill on the opposite track. Compressed air is used to retard the cars when necessary and to pre- vent a runaway should a_ cable break, which is not probable. The solving of this problem has placed at the dis- posal of homeseek-. ers a_ delightful section of the city for residences. Too steep for cars toclimb. The diagram shows how one car pulls the other up A simple device which may be attached to any hat to make it conform closely to the shape of the wearer’s head jections which are stuck through the cloth tube. These serve to keep the cloth attached to the metal strip and may be pushed through the hat crown to keep the device in place. The finishing touch is an elastic cord which is used to tie the ends of the tube together. By means of this cord the hat is made adjustable to fit the head even when the wearer has just received an inordinate amount of unexpected praise. Its elasticity will take care of any ordinary expan- sion, but it may be untied and loosened up on special oc- casions. A hat so equipped will be as stationary on the motorist’s head as the approved peaked cap and equally as defiant of the wind. 412 Making an Amusement Park Out of a Vacant Lot WO boys of South Andover, Mass., with some mechanical skill, recently found that a shaded lot can be converted into an amusement park at a cost of about fifty cents, the only purchases necessary being some Popular Science Monthly He Hitches His Fishing Line to a Five-Foot Kite ISHING for Corbina with kites to carry the fish lines into deep water is the innovation in angling recently in- augurated by Thomas McD. Potter, of the Los Angeles motorcycle club at Seal Beach. nails and a few packing boxes for the merry -go- round. With these and some oak saplings, which were cut down in At Seal Beach ' there is a fine Cor- bina ‘“‘hole” just2crer enough from the pier to be out of the reach of the best casters. nearby Boats, of woods, they course, could constructed a be used, but crude but they cost highly satis- more than _ factory -car- kites, are ousel which conducive of soon covered seasickness, the cost of and don’t of- { construction fer half the and brought sport that in clear kite fishing profits for the does. entire sum- The proprietors of the homemade merry-go-round charged Potter does mer. one cent a ride for children and adults and made money his fishing as The oak illustrated in saplings formed the arms of the supporting framework. They were eight in number and eight feet long. Eight being the magic number, accommodations were pro- vided for eight persons, regardless of weight, and eight minutes was the duration of the ride. The motive power was furnished by the promoters of the idea, who took turns pushing on a bar attached to the central support. According to the juvenile patrons of the improvised amusement park, the only thing lacking was the music, without which a merry-go-round loses much of its thrill. When a whistling quartette and a harmonica failed to meet the demand of the patrons, the promo- tors found that their savings for this first season would have to be invested in a phonograph or hand- organ in order to double the proceeds next year. the drawing below. Better sport cannot be imagined, while from the mechanical point of view the method is quite as satisfactory as it is original. The kite used is about five feet high, which is big enough to have sufficient ‘Vift’’? for almost any fish that chances to get on the hook. When the line is pulled in the fish is hoisted to the kite, where it re- mains until the kite e is taken in. og x bgate ring ‘Kite string a § ee ne When a fish gets on the hook the kite bobs up and down. A quick pull on the line raises the fish to the kite Measuring the Wear of Roads A means by which the right material for the right place is determined HERE are now approximately two million, three hundred thousand miles of public roads in the United States, not including the streets of our incor- porated towns and cities. The materials which are used in them differ, varying from concrete and macadam to cob- ble stones concrete blocks shown in the photographs. One of these blocks is pivoted on the ver- tical rod which passes through it in front, the weight of the block being utilized to keep the wire taut. By placing the vertical rod of each block so as to stand on its _fespective brass plug, and by then and dirt. The _ determining of the right material for the right placeisa problem the solution of which would save many millions of Rack re ad yeas Jength of aleel, Di rev Drill for borin of brass plug the road adjusting the length of the wire until the bubble- level holes on oe sides of shows the rod to be “‘plumb,’’ the fine wire will always stretch across the road in a certain line dollars. which will _The impor- notvary,how- tance of this. ever much consideration the road has led the may be worn Be ae Couinment with which the wear oa roads is STI hak accte blocks hold the fine wire which is stretched across the roed Having es- Rural Engi- tablished a neering to attempt to secure definite in- measuring line, the rest is easy. A steel formation on the wearing qualities of dif- ferent materials under different conditions of traffic. For this purpose, the office has adopted a method which is very accurate. A brass plug is permanently buried in each side of the road, three-quarters of an inch below the surface. Between these plugs a wire is stretched by means of the block is placed upon certain spots across the road and a caliper measures the vertical distance from it to the wire. This can be obtained very accurately because the cal- iper screws upward and when the top of it just touches the wire, an electric circuit is closed and a buzzer rings. Repeating this measurement reveals the amount of wear. A fine wire is stretched across the road. By noting the differences in distance between it and the road at intervals of time the rate of wear of the road is readily determined 413 The Hottest Heat The highest temperature ever reached by man is 9400° Fahrenheit By Raymond Francis Yates NTIL late years the greatest heat man | | possessed as an industrial agency was that of the ordinary fuel furnace in which temperatures approaching thirty-two hundred degrees Fahrenheit were possible. While these temper- chemistry. They resist most acids and rapid changes in temperature. The Wonderful Thermit Process The next step in realizing high tempera- tures by means of atures were indis- pensable and im- portant utilities of industry at the time, they are insignifi- cant today in com- parison with the heat employed in the commercial pro- duction of rubies, calcium carbide, car- borundum, graphite, and steel. ' The two. great allies of man today in the production of heat are, in order of rapid chemical ac- tion was discovered by Professor H. Goldschmidt, of Es- sen, Germany. This is called the ‘‘ther- mit’’ process, and it produces a tempera- tureas highas thirty- four hundred degrees © Fahrenheit. A furi- ous heat is produced by thermit because of the great chemical affinity existing be- tween oxygen and aluminum. If gran- their importance, chemistry and elec- tricity. A gas composed of mixed hydrogen and oxy- gen when ignited burns so furiously that it pro- duces a temperature of thirty-six hundred de- grees Fahrenheit. Util- izing the combustion of these two gases as a source of heat, a French- man, M. Verneuil, has commercially pro- duced rubies, by fusing alumina with a trace of chromium oxide as the coloring medium. So perfect is this imitation gem that it is chemically impossible to dis- tinguish it from the natural article. The oxy-hydrogen blow- pipe is also used for welding. hydrogen—” Workman welding a broken steel frame with heat from an oxy-acetylene blowpipe Granulated Carbon, ulated iron oxide and aluminum are mixed together and prop- erly ignited, the iren rapidly loses its oxygen to the aluminum accord- - ing to the following An oxy-hydro- simple equation: gen blowpipe used for weld- ing purposes Aluminum-tiron oxide= Aluminum oxide-++iron After the reaction has been completed, the iron will be found in a molten state just beyond its boiling point. The oxides of many other elements act in the same manner. This makes the thermit process a’ very valuable asset to the metallurgist and chemist. Not only has thermit proved itself an ally of the metallurgist, but of the engineer and mechanic The temperature of the flame. is just beyond the melting point of quartz, and as well. It has been found that if a small amount of titanium is placed in thermit, by its use, tubes, flasks and many different pieces of quartz chemical apparatus are constructed. Quartz vessels are invaluable in ae | Iron cylinder7 Professor Moissan made wonderful imitation. dia- monds with this apparatus 414 it forms an alloy with the molten iron which makes it invaluable for welding pur- poses. A few years ago, a fractured casting, no matter Popular Science Monthly how costly, had to be relegated to the junk heap. Today, it can be repaired easily and perfectly by the use of thermit with a trifling expenditure. In the photograph be- -lowwillbe seen the thermit processinopera- 4 fa tion at the Brooklyn Navy Yard. Greater even than the heat of thermit in the temperature scale is that attained with the flame formed by the combustion of the gases, oxygen and acetylene, in the pro- portion of 1.7 vol- umes of the former and I volume of the latter. In the apex of thecone of a flameso produced, a tempera- tureofsixty-threehun- ’ dred degrees Fahren- heit is realized. The hydrogen, which is freed from the acetylene, sur- rounds the flame and pre- vents a loss of heat and confinesit toasmall space. By a suitably constructed blowpipe, this little flame is used to great advantage even by a com- paratively unskilled workman for the quick repair of small, broken castings where Using the electric arc to weld together the parts of a large motor armature AlS the use of thermit would be impractical. To go further in the explanation § of methods for attaining high temperatures, we must introduce electricity— the greatest heat-creating power that science commands. What the Electric Arc Has Done For those who are not familiar with the theory of the elec- \ tric arc, a brief ex- planation of its op- eration will be given. If two car- bon rods, maintained at a sufficiently high difference in voltage, are made to touch and then quickly withdrawn, an arc will be formed. When therodsarebrought into contact, a spark is produced hot enough to _vaporize a small portion of carbon, which fills the gap with carbon vapor. ~\ The carbon vapor thus liberated reduces the electrical resistance of the gap from many thousand ohms to a few hundred. An electric furnace of the arc type pouring-out part of its three-ton charge of molten steel, which has reached a temperature of 3600° Fahrenheit through the affinity between oxygen and aluminum 416 The current then uses the path of vaporous carbon as a conducting medium and heats it to a great temperature. The greater the ‘current intensity used, the greater will ‘be the resulting heat produced. Making Diamonds at Home -The furnace with which Moissan; pioneer user of the electric arc, conducted startling ex- periments and. made many discoveries, is most simple... It con- sists principally of an Magnesium Tape arc drawn between two - ferric Oxide Jarge carbon electrodes and Granul- ‘and, supplied with a sean ‘very heavy current. The arc is enclosed in the cavity formed by two large limestone blocks. In this simple furnace Moissan produced a temperature of sixty-three hundred degrees Fahrenheit and, had it not been for the fact that carbon boils at this temperature, we can not predict how much further the temperature could have: been carried. With the aid of his electric furnace -Moissan made as many as one hundred and fifty valuable contributions to science. Among his more notable discoveries was the production of the carbides of nearly every metallic element and the artificial creation of the diamond which is crystallized carbon. The science of electrothermics has de- veloped many new industries and sub- stances, not only through the efforts of Professor Moissan, but many other inves- tigators as well. are used Graphite Crucible The essential elements which in preparing thermit for the laboratory Popular Science Monthly and offer such resistance that temperatures as high as sixty-three hundred > ‘dears Fahrenheit have been produced. -% - It was by means of the electric femme that Hall made aluminum a commercial article. Before his time it was a laboratory curiosity. Taylor produced carbon-disul- phide and Willson developed a means_ of producing calcium carbide on a commercial . scale. * -: an she? The highest temper- ature ever reached by man was produced - a few years ago by two English experimenters, Sir - Andrew Noble and Sir F. Abel.- This was done by an explosive called cordite, which. is a form of smokeless powder composed chiefly of guncotton, nitro- glycerine and mineral jelly. When this was exploded in a durable steel cylinder, a temperature of ninety-four hundred degrees Fahrenheit was produced. This was due to the suddenness of the reaction, and, although of momentary duration, it was an interest- ing scientific achievement nevertheless. With the aid of cordite, Sir William Crookes was able to make small diatnonds, Sodium Peroxide Doff Your Hat to the Goat Milk Saves Babies’ Lives HEMICAL studies made recently at the Agricultural Experiment Station at Geneva, N. Y., to ascertain the value of goats’ milk as a substitute for cows’ milk showed marked differences between the two kinds of Nor have all the industries founded made use of the arc in their furnaces. Many, such as Acheson’s for the production of carborundum and graphite, are of a differ- ent type. In Acheson’s_ fur- nace the sub- stances to be converted form milk but could reveal no reason why ‘‘Goats’ milk agrees bet- ter with babies than does cows’ milk,” the fact that it does so being unques- tioned. The Station main- tains a herd of goats in order that the inves- tigations may be carried out a part of an electrical circuit street-car rails. Using the intense heat of the electric arc in welding Note the head gear worn by the man under the best conditions. When folded up the cover is placed in- side the casing. At right: The rear seat full of luggage A Dust-Proof Cover to Keep the Automobile Luggage Clean HE luggage which you are carrying in the rear seat of your automobile need not be exposed to dust and rain if you use a cover recently designed by Arthur Paulson, of New York city. It is inexpen- sive and convenient. When stretched over the rear of the car, covering the entire rear seat and Popular Science Monthly 417 By means of a dozen fasteners the cover can be se- cured in position easily and quickly in position on the floor ard on the seat, the cover is made fast by attaching it to fasteners placed on the cover top, the doors of the automobile and the back of the front seat. In addition to keeping your luggage clean, the cover protects it from thieves. A Little ‘‘Safety First’’ Device for the Bill Folder NEW bill folder has been de- the floor space in front of it, as one of the accompanying illustrations shows, it will protect everything that you carry from the dust of the road. The cover consists of leather or rubberized canvas which has the shape of the rear portion of the car. Ordinarily, the cover is folded and is stored away in the cloth casing which surrounds the automobile top when it is folded away in the rear. One end of it is attached by fasteners to the edge of the casing. When it is to be used, one pull will suffice to bring it out from its posi- tion under the casing. After the luggage has been placed With the safety device the folder can not fall out or be stolen signed which will stick as close to you as your coat itself. It has a snug-fitting clamping de- vice which holds it flat and fastens it to the inside of the pocket so that it will not fall out when the wearer is stooping and will not re- spond to the magnetic fingers of the pickpocket. When the owner himself wishes to remove the bill folder from the pocket hesimply presses on the long outer bar of the clamp and releases the folder from the pressure. It then slips out easily and is as readily replaced. The device does not in- terfere with the comfort of the wearer when he is sit- ting down. Popular Science Monthly * te. s { as ae m= ¢€ * ri s sgnse* tee when pressed for time, and as a rule they take the time of five hundred laborers in five minutes. This means that instead of, long lines waiting at the windows, the strings of men are short and quick moving. Before each clock is an open window and above it is the sign indicat- ing the numerals checked there, from 1 to 250; from 250 to 500, etc., for the four clocks will take care of 1,000 records. The stevedore shows his brass check or Professional time-clock punchers operate the clocks for five calls out his number as he reaches the window. hundred longshoremen at the Bush Terminal, Brooklyn, N. Y. Experts Punch the Time Clock for Slow Stevedores VEN in this age of specialization it is not considered necessary to hire an expert to punch your time clock, that detail being left to the worker in the average industrial or commercial plant. The operation seems simple enough. Merely swing the indicator about the dial with its circle of numbers, stop at the right number and register your time by a swift pressure of the hand. But if a plant employs a large number of men it may be found economical to employ not one but four expert time clock punchers, operating as many instruments, and the saving of working minutes runs up into a total of days and months in a short period. At the huge Bush Termi- nal in Brooklyn, N. Y., five hundred longshoremen are employed every day on the average, magnificently mus- cled giants well fitted for the work of juggling pig iron and sacks of coffee, but with finger tips far from delicate and perhaps a bit slow. Therefore it is about as well as they can do to punch their own time at the rate of six or seven stevedores a minute. With four clocks, that would be twenty-eight a minute at their maximum speed. A Sanitary Dining Car. No Hospital Can Be Cleaner NEW dining car on one of the western railroads has some unique sanitary features. The kitchen is ventilated so thoroughly that dust and cinders cannot enter the car. A continuous flushing ar- rangement keeps the receptacle for milk and cream clean, and the fish is kept in a separate refrigerator. A fan outside the car at the rear drives out the odors. The car cost $30,000. It seats thirty-six passengers. This Shrewd Little Marketwoman Is Made of Figs DOLL with which young- sters can be amused on rainy days, and which lends itself to a curious effect in decoration may be made from dried figs and bits of cloth from the scrap-bag. The little marketwoman shown in the accompanying illustration is a good ex- ample of the results to be obtained, The stem of the fig makes a_ characteristic nose. The eyes are those of an old discarded bisque doll. The mouth is a mere incision in the fig skin and the neck is an- other smaller fig pressed The professional time- clock punchers can. handle two hundred men a minute Dried figs are responsible for the keen expression of this very ancient Katrina of the markets up into the head. The basket is also a fig with a worsted handle. - | a great shell cra- _ may be improvised into forts Although it explodes a giant shell it is harm- GRAZE PELLET PERCUSSION PELLET PERCUSSION SPRING ters which form such commodious quarters for the Tommies to stretch in after weeks of confinement in narrow trenches or which On occasion, are mostly formed by the explo- The Detonator Head less until it leaves the muzzle of a gun PERCUSSION NEEDLE _ PERCUSSION -DETONATOR contact with a solid body, the graze pellet with its de- tonator is thrown violently against the needle in the cap and exploded. The re- sulting flash passes through a central hole in the graze pellet and ignites the powder in the gaine tube and sion of high-explosive shells fitted with de- tonator heads, al- though similar craters may also be formed by detonated shrap- nel. The shattering The body of the detonator head carries within it a cylindrical block of material known as a graze pellet, while the cap of the head carries the percussion needle. An alternate detonating device is also provided in the body—one which becomes effective only after the graze pellet has been released by contact. This second detonating mechanism is provided simply to assure explosion and is probably seldom essential is transmitted through it to the explosive charge at the base of the shell. Protruding from the lower end of the graze pellet is a teat of fortifications, the demolition of supply depots and most of _ the damage caused by explosive shells is made possible through the agency of the small detonator fuse or head fitted to the nose of each projectile. This little device is simple in construc- tion and is of interest in that two distinctly different forces are required before it will _ become effective—a centrifugal force for - _ unlocking the mechanism and a detonating force for the explosion. On being fired from the gun, the projectile travels at a high rotary speed and the dedent spring is compressed, so that the _ dedents, acting as virtually one piece, drop down into the dedent spring cavity. The twirling of the shell throws the upper de- dent out of plumb as soon as it drops into the spring cavity. On the recoil of the spring the dedents lock into the larger hole. The twirling of the shell, due to the rifling of the gun, also causes the centrifugal bolt to fly away from the graze pellet once the upper dedent has dropped into the lower cavity, so that the graze pellet is held in position simply by the coiled spring between it and the cap. In the top of the graze pellet is fitted a detonator charged with a highly explosive material. On the arrest of the flight of the projectile, through which fits into a hole in a kind of transverse carriage known as the percussion pellet. This pellet carries at one end a holder containing at its center the percussion needle around which are a number of flash holes giving direct com- munication through the percussion pellet to the top of the gaine tube. Opposite the percussion needles carried in the body of the head is a second charged detonator. Behind the percussion pellet, or, rather, within the hole bored in its opposite end, is a spring, held in compression by the teat of the graze pellet. When the graze pellet is thrown forward by the contact of the projectile, this teat is withdrawn from the hole in the percussion pellet, releasing the percussion spring. This throws the per- cussion pellet forward forcibly, resulting in the contact of the percussion needle with the second detonator. The flash created is transmitted through the flash holes surrounding the needle and passes to the top of the gaine tube, thus doubly assuring ig- nition of the explosive charge in the shell. This second detonating arrangement can not operate until the graze pellet has been thrown forward into contact with the graze needle, and the graze pellet cannot travel forward until the centrifugal bolt has been thrown out of place, which, in 419 420 Popular Science. Monthly Growing Umbrella Handles to Sim- ulate Freaks of Nature turn, cannot happen until after the dedent spring has been compressed and the dedents dropped into the lower dedent cavity. Notwithstand- ing the fact that — oa the detonating jj a T is a mistake to state that all the umbrella handles, with their kinks and : GRAZE NEEDLE head is capable CENTRIFUGAL BOLT. f j h j UPPER DEDENT RATE Tansee 1 of causing the in- CENTRIFUGAL, BOLT cc eone twists and bends, are freaks of na- ture; they are, on the stant explosion of HOLE SCREW PLUG the projectile, it “LOWER DEDENT is in reality a DEDENT SPRING GRAZE PELLET PERCUSSION PELLET harmless piece of mechanism until it leaves the muz- zle of the gun. In fact, a pretty heavy blow of a sledge hammer could be given this detonating DEDENT HOLE SCREW PLUG contrary, the result of care- ful training on the part of some um- brella farmer. A moment’s thought and you will ad- head without any aire oom | Ai PE, mit that, in danger of explod- all your ram- ing the projectile. The graze pellet fits loosely into the fuse body and is held _—_ pes through : : in position by a small block of metal kn i In the illustr ation bolt which fits asa ae Mac te the eae can ae the woods, at the right is trudes over the shoulder of the graze pellet. Behind this you. never shown the various centrifugal bolt and holding it in place is the upper dedent. saw anything parts of the This is a simple rod with a ball end fitted into a cup-shaped _ like the han- mechanism and receptacle in the lower and larger dedent. Under the lower _ dles on dollar : 4 dedent is a coil spring simply stiff enough to hold the lower their relation to dedent up against the shoulder formed between the lower umbrellas ob- each other. and upper dedent holes, at the left of the illustration above tainable in the city. In France there is a plantation of several hundred acres devoted entirely to the rais- ing of umbrella handles, canes, and riding whips. The artful handle grower cuts the trees a little above the ground level and a number of saplings sprout from the roots. Then the buds of these sprouts are nipped off. By cutting the bark and training the shoots, almost any variety of design may be produced. After two or three years - the crop of umbrella han- dies and walking sticks is harvested and after the necessary treatment, the product is ready for the market. If you feel that the raising of beans and po- tatoes is too prosaic, try the — artistic cultiva- tion of original designs in um- brellas and canes. A New Vest Attachment to Hold the Trousers in Place NEW attachment for the vest holds the trousers in the proper position and prevents the vest. from “riding up.’”’ Four strong loops are sewed to the vest on the inside so as to be invisible; these then pass around the belt of the trousers and fasten with a clasp. When the vest is buttoned the trousers and vest are held in position so as to look neat; if desired the belt may be worn loose so as to allow ease of movement and prevent binding. The attachment is also useful to those whose work requires con- siderable bending and stooping and causes the shirt gradually to work up. The principal argument against this attachment is This belt holds the vest down that the vest would have to and the trousers up and keeps be worn summer and winter. the shirt where it belongs Popular Science Monthly A Tire Pressure-Gage No Bigger Than a Pencil gage fits in the automobilist’s pocket. It measures the tire pressures in five-pound increments and works on the plunger pump principle with a small piston forced out by the air pressure against a coil spring. The piston rod is graduated in pounds and has notches on one edge which keep the rod ex- tended to the highest pressure until it is snapped back by a push of the finger. Three Roadmaking Machines in One NEW grader that does the work of several ma- chines heretofore required for finishing up a road has been invented by Charles M. Ander- ‘son, of Denver, Colorado. The principal element of the invention is a vertical, ad- - justable frame having coulters which loosen and distribute the earth. Following the coulters comes an adjustable scraper, which levels the earth pul- verized by the coulters. Following the scraper is a roller which packs the ground 421 desired slope or arch, according to the adjustment of the coulters and scraper. The frame of the machine is provided F the same size as a pencil, this tire® with a universally movable wheeled axle at are This is 45]b, pressure its forward end, to which the front wheels ~ mounted. This construction of the frame makes it possible to operate the ma- chine in any desired direction and over rough and broken surfaces with- out danger of breaking or unduly oe straining the working parts of the ecg ga machine. Either tractor or horse reading until power may be used to run the ma- snapped chine. back into place j : Increasing England’s Crops by Electricity NE way England will help Metal to prevent German sub- Felt . i i ; i piston marines from starving her out is sete by increasing her home crop by vee electricity: Experiments have Air in Circular rubber nipple The pencil-like gage works on the plung- er pump principle . Plugto keep growth. tive valve five per cent. upon cereals and other field crops which been under way for determining how high frequency electric cur- rents will best stimulate crop Prot; V. aks Blackman, of South Kensing- ton, the eminent agriculturist who is in charge of the work, has already shown on a small scale how oat crops can be in- creased from fifty to eighty- This work is to be extended down, forming a level road surface of any will be planted over no less than fifty acres. A road-grader which does the work of several machines. It loosens the earth, distributes it, pulverizes it, and packs it, forming a level road surface of any desired slope or arch Solving the Car Shortage’ Prabien We have enough cars, if we use them properly re aca a The regular trading unit of the sugar industry is four ‘hundred bags, weighing 40,800 Ibs. Notice the waste of car space. HE lack of sufficient cars is as detri- mental to a railroad as a shortage of guns is to an army. The scarcity of cars which confronts America is thus one of those present-day problems which we must set ourselves to solve immediately. For upon an efficient transportation or service at home depend favorable condi- tions abroad. Our shortage of cars reached its climax in May, when so much material was tied up that it would have taken an extra six per cent of the country’s total equipment to move it. To add this amount of cars when Russia and the rest of Europe will tax our builders to the limit, would be as difficult as it would be unnecessary. There is a better way. Only about one-half or less of the car capacity of the country is utilized. room the interior of the */ Railing” a erator’s port er left boat before she goes , \ 7!'? duck \\ hand side, while over. Do all the ‘y_[Platform buoys marked with work before the boat Fig.20 red and black hori- is put in the water; for the chances are Cross timbers it will never be done venvas ip if left until after |S'"6a [blocks the boat is launched. limbers laid between platforms to carry boat during the winter Fig. 20-A See that no paint gets on the screens covering the intake to water cooling- pipes, or closets, to Canvas aml Turnbuckle a ridge Turn-buttons Three ways to protect the motorboat from the weather when it is not in service zontal bands should be given a wide berth under all conditions as they are generally used to locate a wreck or some other submerged obstruc- tion. Buoys marked with black and white perpendicular mark stanchion Fig. 17 Popular Science Monthly “NRollers Fig: 23 Where a boat-house is not used the boat must be removed from the water by means of a car, skids or rollers and the boat secured in its stationary out-of-season position by blocking ings are known as channel buoys and are situated in mid-channel. Steer close to these on either side. These markings mean the same on any style of buoy. The harbor or channel buoys are num- bered from seaward, each harbor or channel having its own system of. numbering, although the black or port buoys carry the odd numbers, as I, 3, 5, and 7, while the red or starboard buoys carry the even numbers as 2, 4, 6, and 8. Spar buoys are placed where the water is not greatly disturbed. They are the most frequently used as they . are visible at long distances. Nun and can buoys are built of steel and are used in the more disturbed waters; the nuns mark the starboard side of the channel, obstruction, or mid-channels, and the cans mark the port side, the colors indicating upon which side they are to be passed. Gas buoys, bell buoys and whistling buoys serve the same purpose and carry the same message, according to color and num- bering, with the additional advantage that the bell buoy gives warning of its location in a fog, and the gas buoy flashes its location at night. On the chart, red buoys will be colored red, with the number alongside, and black buoys will be shown in black and numbered. Danger buoys are colored with black and red horizontal stripes, while mid-channel buoys-will be marked black and white with perpendicular stripes. The operator will occasionally find buoys carrying a half num- ber such as 414; 514, etc., which merely shows that a new buoy was placed after the main string had been set. eee When running into shoal water the op- erator will usually notice a heavy ground swell; the water will take on a light green color. Rocky bottoms with little patches of sand between the boulders take on a reddish color from the. weeds or a deep Care should be taken to see that the shoring does not rest on any one plank in the hull, but on several planks immediately over a rib to prevent damage to the support from sudden jars Popular Science Monthly green from the rocks although the small white blotches of sand are usually the first to attract the attention. Of course, the preceding remarks apply to clear water and will not hold good where the water is con- tinually agitated and clouded by mud or refuse. Swirling water usually indicates a shoal or some submerged obstruction or may be the result of a divergence of current. - When ready to cast off from the mooring, haul in the slack on the dinghy’s painter to prevent the bight from dropping into the water and fouling the propeller. Test the engine to make sure that it is running and that the clutch 429 These lights are rigged as shown in Fig. 31. The white light shows over an arc of 180 degrees while the starboard and port lights, called side lights, show over an arc of 90 degrees. As will be noted from the draw- ing, the starboard or right-hand light when facing forward is green, while the port or left-hand light is red. Before completing this series of articles the writer wishes to call the attention of every motor-boat operator to the necessity of being courteous on the water as well as on the land. When. passing a boat load of timid women and children slow your boat down rather than cause the wave from your “ wake to fright- is working properly, and let go. Allow the boat to drop back from the mooring enough to allow you to clear it and then start ahead, taking care that you do not veer off so sharply that the stern of the boat will foul in passing the buoy or dock. en them or maybe capsize them. When you see another boat in trouble run over. to them and offer a tow;< of at any rate ascer- tain whether they would like to have you send help out to them. Re- member that it does not cost a cent to be kindly and you “The Rules of the Road” are published in booklet form by the Steam Boat Inspec- tion Service and give complete instructions as to. the proper equipment for motor-boats of various sizes. Four units, however, should be included. on every craft whether large or small; they are, a good heavy anchor and at least 150 feet of good heavy line to use with it; plenty of life preservers; a good substantial whistle or fog horn and the necessary lights to be used at night. Removing a motor-boat from: the water preparatory to beaching it so that it may be housed for the winter can never tell when you mey be glad to have the compliment returned. Take good care of your engine. AQ little extra care and attention when laying ft up for the winter or even when it is to be out of commission only a few weeks or days will prevent a variety of troubles later on. Investigate . pecular noises.. They invariably mean that something is out of gear. Ascertain the cause and remove the trouble before the engine is laid away. ibe Spar Fig 29 _ Buoys have been called the sign posts of the waterways and there is probably no definition which could state their purpose more clearly. The color designates the course of travel 430 A Tin-Pan Orchestra to Scare the Birds Away from the Garden SCARECROW is often nothing more than a-place where the birds may rest after enjoying a feast of delectable sprouts. : Therefore, the farmers of Imperial Valley, California, have discarded it as a means of keeping Popular Science Monthly the spears can be swung in any direction. A troop of horses dashing onward with the spears facing front would have a telling effect on the enemy—in theory. For, you see, to thrust these spears for- ward in the faces of the enemy would take the strength of a giant. By pulling down on the extension levers, the motion imparted to the operating racks are supposed to ro- tate the pin- pests out of sprouting vege- table gardens. They have found an ef- fective substi- tute which keeps not only birds, but dogs and cats away. The substitu- tion is an im- provised or- ioned arms, and thus open the tongs. But unfortunately, the pinioned arm construc- tion has been made just the inverse of the lever! This, together with the enormous friction which chestra com- posed of tin pans strung on wires, shown in the accompanying photo- graph. When the wind blows, the pans clatter together and the music set up causes the birds to move on to more har- monious quarters. Threads are attached from the wires to the branches of nearby trees, so that when there is no wind, the pans are rattled if the birds alight on the limbs. Dr. J. B. Keller, of Banning, California, is the originator of the garden orchestra. Thrusting Spears for Cavalry—Which Can- not Thrust NSPIRED, per- haps, by the ’ gallant use of spears by the knights of the Middle Ages, an in- ventorin Rock Island, Illinois, has taken out - patents on cavalry spears which are to be thrust into an enemy me- chanically. His weapon consists of a short, sharp- ‘pointed spear carried on an extension tong on either side of a horse. Each tong hinges on a saddle arm so that by moving..a lever, Tin pans strung on wires make a clatter in the wind and scare the birds away from the garden or orchard By operating the levers, this device is supposed to thrust its spears in any direction upon the enemy would develop by the mem- bers guiding the arms connected with the pinioned ones, would make it necessary for a half ton pull to thrust out the spears! Even if it were possible to thrust them, this weapon affords no protection from the opponents’ cold steel! The device could hardly be ex- pected to get further than the patent spec- ification drawings. However, it is a patriotic effort on the part of the inventor - and as such is deserving of consideration. The flights of imagination of the inventive genius of the day may result in many impractical devices, but ideas are being constantly advanced which only need rounding off and developing to make them useful. ae! oa a 4 Swinging lever Extension lever Popular Science Monthly Detecting the Undertow Before It Catches the Swimmer ESPITE the precautions taken by bathers and by beach resorts in pro- viding safety lines, life guards, rafts and boats, each summer season a number of swimmers are swept to their death by the treacherous undertow, which is a powerful ocean current which goes seaward from a shore on which heavy surf is breaking. Ofttimes an undertow is not-detected until one or more swimmers disappear from view. It may shift from one part of a coast to another, suddenly car- rying away bathers from a resort that is supposed to be free from such danger. With an apparatus invented by Martin M. Voorhees, of Oak Park, Illinois, it is not only possible to detect the presence of an undertow but to send out a signal to the bathers so that they may be warned in. time to return to shore. As the accompanying illustration shows, the inventor has designed a disk with a ball lever which indicates the strength of the undertow at all times. It is set in the water, preferably at a point where the water is dangerous for unskilled swimmers to venture into. With a strong undertow running, the disk, mounted on_ hinges, swings outward, pulling a cable which is attached toa signal post situated on the beach. _A pull on the cable accomplishes three things: It causes the dial on the post to register the force of the undertow: it rings 431 The garage as it looks when completed. Double swing doors admit the automobile At left: The frame- work of the cathedral- like garage. Sharp angles are eliminated A Little Garage Built with the Contour of a Cathedral HE Gothic lines which characterize the garage here shown were not the result of any religious fervor on the part of the builder. They simply conform to a pop- ular style of architecture now utilized in barn construction in southern Canada. The absence of sharp angles and ugly cornices forms a pleasing contrast to the familiar style of garage which resembles nothing so much as a huge packing-box deposited in the rear of the house. Double swing doors are used, admitting any automobile with the top up. With the possible exception of the curved side pieces an electric gong, and. it causes the in- candescent bulbs tolight. Persons hear- ing the gong ring or seeing the warning sign illumin- ated are thereby ees ss S ees a = f this style of garage is easier to build than the us- ual type. Be- cause of its sloping sides it does not of- fer as much resistance to: high winds as the ordinary warned garage, and ‘against re- for this rea- maining long- son is con- er in the wa- sidered safer. ter in that Ft has a¢ locality. When an undertow is running the device rings a bell and lights a warning sign telling swimmers of the danger windows. oe Science M onthly The pilot’s wheel which controls the direction of the primitive ferry boat The force of the current against the side of the boat carries it across stream Making the Missouri River Drive a Ferry Boat LTHOUGH Bellevue was the first settlement in Nebraska, it never constructed a bridge across the Missouri River. In 1810, the American Fur Com- pany had established a post at that place and it seemed as if the village would become a thriv- ing city. But, by a turn of fate, the place re- a. mained a small town, and no bridge was ever built between Omaha and Platts- mouth, a distance of about twenty-five miles. For some time a gasoline ferry boat was main- it is propelled by the current of the river at no expense. Two poles, eighty feet high, made of iron pipe, were erected, one on each side of the river. Between them is stretched a steel cable to receive a pulley. Ends of a rope are attached to the bottom of the pulley. The rope is fastened to each end of the ferry boat, then brought along the side of the boat and passed around the hub of a wheel, resembling the a wheel of a steamboat. When the wheel is turned it winds up the rope, so that the length from one end of the boat to the pulley is shorter than the length from the otherend. This naturally turns one end of the boat upstream. The force of the current, act- ing against the boat, pro- pels it across the river. To recross, the rope is shortened. Alas! The Price of This Kiss Was Instant Death HE top of a pole carrying nearly four- teen thousand volts of electric current is a precarious trysting place. The accom- panying photograph of two squirrels en- gaging in what proved to be their kiss of death shows just how dangerous it is to spoon adjacent to elec- tric light feed wires. The two squirrels had evidently made an engagement to meet at the top of the pole and look for the lady in the moon. Arrived there, as the latest fictionists say, they were in the act of giving the cus- tained at Bellevue, but it was not de- pendable and was abandoned years ago, leaving farmers with no means of crossing with their wagons and live stock. An old- fashioned mode of crossing the Missouri river by ferry was then revived. The old-new ferry is interesting because One squirrel was on the line and the other on the grounded brace when their noses touched tomary lover’s greet- ing, when the touch- ing of their noses caused a short circuit and the souls of both animals were wafted heavenward. It was indeed a kiss of death. From the nature of the burns it was established that one squir- rel was on the line, and the other was on the brace which is grounded. Maybe you have special needs. of the magazine. Write to the editor about anything within the scope He will be glad to help you. Popular Science Monthly An Improvement in the Clock Scheme of the Daylight Saving Plan HE plan to gain thirty hours of play in the sunshine each summer month by daylight saving, ought to appeal to every pleasure and health-seeking Ameri- can. It is almost equivalent to getting more pleasure for nothing. And _ then think of. the cartload of money that will be saved in this country by a hundred and ten million of inhabitants heating and lighting their homes for one hour less each evening. It is contemplated moving the hands of the clock one hour ahead in the spring, and turning the hands back again in the autumn. This would entail a minimum amount of confusion. People would start to work, eat their meals, and keep their engagements when the clock hands point to the customary hours. This scheme of moving the clock hands is a good one, but there is another plan which is slightly better. Why not move the clock dial backwards? The same ad- vantages would be obtained, and besides, at noon the hands would be at the top of the clock, at sunrise and sunset they would be at the bottom, as they always have been ever since the present style of clock has been used. This could be accomplished very simply by means of curved slots and screws, as shown in the illustrations. An- other way to accomplish the same purpose would be to use two separate, suitably marked dials.. This way of working out the day- light saving scheme would be really scien- tific. Moreover, in the case of striking clocks, it would make unnecessary, when the hour is to be set back in the autumn, the turning of their minute hands eleven times around. For the striking mechanism of these clocks cannot be set back by simply moving the hands. Clock makers assert that the interference with the mechanism caused by alter- ing the position of the hands im- pairs the accuracy of the timepiece. The hour hand should never be tampered with and the minute hand veryseldom. Countersink Instead of moving the hands ahead, the clock dial is moved back in the manner indicated a iif oe That part of the pole above the platform will have to be removed and straightened How a Cyclone Bent a Two-Hundred- Foot Flagpole ei Pgh zephyr which early this Spring developed into a cyclone of the first magnitude, took a hurried trip to Kansas City, Missouri, and left its card in the form of a bent flagpole in Swope Park. The pole is composed of two main sections which are divided into a number of smaller ones. In repairing it the upper main section which is fastened at the middle _ of the pole will be removed and lowered. It would have been less remarka- ble had the pole been blown down or actually snapped off. The bend simply indicates the freakishness of such storms and thequickness with which they change their direction. Countersunk screw PP Countersunk screw A New Treatment for Distemper in Dogs By Dr. George W. Little | Chief Surgeon of the American Society for the Prevention of Cruelty to Animals ) *: other disease of dogs is more prevalent and, with the exception of rabies, more fatal, than “distemper,” a disease peculiar to dogs and young horses. Its cause is a specific infection or poison finding its way into the system through the lungs and air passages. Young and growing animals medicines, vaccines and antitoxins, I have found only two medicines that have proved of exceptional value. These drugs are inula and echinacea. They are non-poison- ous and work together to raise the natural resisting power of the blood against invad- ~ ing bacteria and disease. Administered in are generally at- tacked. It runs a course as a catarrhal fever, affecting all of the mucous mem- branes of the body and is in many cases accompanied with certain nervous symptoms and erup- tions of the skin. Distemper is highly contagious and is communicated only by infection. The Scotch term for it is ‘the snifters,”’ which conveys graphically to the mind one important characteristic of the hypodermic injec- tions into the mus- cles every -twenty- four hours, inula and echinacea kill dis- temper, finally driv- ing it out of the — system. Five or six hypodermic injec- ° tions are usually nec- essary, alternating © first on one side and © then on the other side of the body. These must be made © by a veterinary who understands intra- — muscular injections. The improvement . in the patient after disease, namely, the snifting noise—half sneeze, half cough which demonstrates the effort on the part of the animal to rid himself of the mucus which accumulates in the air passages. In the treatment of dog distemper many things must be impressed upon the nurse and the owner as of the utmost importance. Strict attention should be paid to the diet. No meat whatsoever should be given. Boiled rice, the broth of meat with fat. re- moved, dog biscuit, milk and stale bread can be given. Vegetables such as peas, beans and ‘asparagus may be mixed with the rice or other food. Food not ‘eaten should be taken away immediately after- ward. Regarding the medicinal treatment of distemper, more specifics have been used aad recommended than in any other disease in the category of dog ills. After numer- ous experiments and the use of all available Injecting inula and echinacea to drive distemper out of two or three injec- tions is remarkable. The dog, seemingly in the last stages of distemper, revives and recovers his appetite and there is a corresponding decrease in the severity of all the symptoms of the disease. The recovery is so rapid that the dog does not become debilitated to any great extent. I have treated eighty cases of distemper, using inula and echinacea. The percentage of mortality in these cases is the only tangi- ble proof, aside from the rapid recovery of the animals, upon which the efficiency of the compound can be based. Of the eighty cases treated, sixty-eight have recovered. The mortality, therefore, is fifteen per cent of the total number. The usual death rate according to the best authorities is from sixty to seventy per cent. The dogs treated were in all stages of the disease. Some had very high temperatures with pneumonia, bronchitis, bronchial coughs and typhoid symptoms. the dog’s system 434. : : on) spark tothe point of A Safety Device Which Takes the **Kick’’ Out of a Ford ‘< WO Wisconsin inventors have recently ob- tained a patent on a device that effectually _ prevents back firing and kick- ing when cranking a Ford with the spark left ad- ~ vanced. an arrangement fast- _ ened to the commuta- It consists of tor which automati- cally retards the easiest starting when the crank is turned. As seen in the smaller photograph at the right, the spark is left advanced, lowering the de- vice so that it comes between the ratchets on the crank and those on the crank shaft. Before the crank can en- Wi gage the shaft, the arm of the device must be f pushed out of the ratchets on the crank, as shown in the large photograph. Pushing this arm out automatically retards the spark to what has been found to be the point where the motor starts easiest. After this the crank is free to start the motor. However, it is impossible to start the motor until the device has been pushed out as far as it will go and the spark re- tarded. Of course this is not necessary where the spark has been retarded before cranking. But in the majority of cases _ where injuries have been sustained while _ cranking the car. fore one was found ments. cranking a car, the spark has been advanced a considerable distance. It is impossible to advance the spark from the seat while anyone is The arrange- ment can be put on the car without remov- ing the timer or chang- ing or altering any parts. More than fifty dif- ferent models were ex- perimented with be- that met all require- With this de- vice iin operation, practically all danger is Popular Science Monthly At left: At right above: ratchets ee comme The safety device between the ratchets. The shaft pushed out of the to automatically retard the spark The Clam-Shell Makes Its Début as an Interior Decoration O make a picture like the farmer boy in the accompanying illustration, you need not be a gifted artist or even a good photographer. All that is needed to secure a perfectly artistic effect is a square of colored cardboard for mounting, a figure cut out of a magazine, fashion sheet or advertisement, and a bit of white cotton or black or brown wool such as is used for crocheting or knitting, and a clam shell. The lines of the face are made with pen and ink. The cut-out figure is first pasted on the mounting board; then the clam-shell head is adjusted and stuck on with mucilage. The placing of the hair affords scope for in- dividuality. The grass and sprigs of flowers are painted in. If you happen to be somewhat of an art- ist, you can paint in the whole figure, but. very good effects are obtained with the paper cut-outs. If the trousers are cut from sandpaper, they will afford a con- venient place on which to scratch matches. The placard can then eliminated from the ‘ The clam-shell cranking up. farmer boy with paper cut-out body and hair of cotton be hung on the wall near the matchbox. © Underwood and Underwood The engineer misunder- _ stood or forgot the sig- nal. This was the result faithfully eyeing each signal as it flies past, figuring on how the next signal is likely to be, watching the gages on the locomotive, and looking after all the other contrivances? Did you ever walk along a picket fence, trying to count the separate staves as they went by? In spite of your best efforts at concentrating, didn’t your mind presently wander? Didn’t the whole thing finally become a big muddle? Do you wonder, then, that the engineer, work- ing under the strain that he works under, sometimes misses his count of the signals as they go by, forgetting whether the last one read ‘“‘Danger’”’ or not? How to eliminate the human element in train operation is one of the really big propositions before the railroads today. Some years ago the New: York, New -Haven and Hartford Railway offered a prize of $10,000 for an automatic stop which would meet all the rigorous conditions imposed—something which would not be affected by sleet, snow and cold, which would not require expensive changes in standard equipment, and which would not fail oftener than once in 1): you ever ride in a locomotive cab, record made by the _ electro- pneumatic signals in the New York subway. It was also pointed out that special regard should be paid to traffic conditions on steam railways and to the fact that any automatic control system must be capable of application to high and low speed passenger trains as well 5 as to freight trains. A host of inventors have applied A a million times, which is about the Engineer Forget ~~ as the result of this prize offer. 4 © } ~ DISTANT SIGNAL The general design of block signals 436 A new automatic train stop which - promises to prevent disaster should signals be disregarded themselves to the problem. No less than fifteen hundred and. seventy- were offered to the railway company inventors all aim to establish an arrangement such that if. the engi- neer does forget or overlook a signal, his train will be brought to a stop automatically. four plans for automatic train stops — The The trouble occurs when an engi- neer runs by a home signal and — into the next block in which a train may already be standing, or a bridge washed out, or other trouble manifesting itself. He runs into the train, or off the embank-. ment into the river. The whole system was designed to prevent this wreck, yet it was powerless to do so because the engineer overlooked or didn’t mind the signal set at danger. If the signal’s mandates could be enforced, whether the engineer paid atten- tion to them or not, the much-to-be desired system would be attained. This brings us to the reason why inventors are endeavoring to produce automatic train stops. Present-day railroading is like the country would be were there plenty of laws but no police and courts to enforce them. There are many rules and regulations in train operation, and signals to point the way, but there is no means of enforcing — them. Nor will there be, unless the new train stops prove to be all that present-day inventors hope for them. All train stops operate on much the same principle. They all seek to set the brakes of an advancing train, should the signal read “‘Danger.’”’ Toset the brakes on any train it is only necessary to open a certain valve connected with the air system on the engine or underneath a car. The auto- matic stops, asa rule, all aim to get at this valve when the train is in danger and openit. The practical method of doing this is hard to work out, barrier which has prevented practi- and put into operation long ago. To stimulate inventors to devise and constitutes the cal train stops from being invented _ - Something is The distant signal Home Signa Track. Distant S ignal) Train Showing a train seeking : et the “home” ee. yond me’’ sig- En : knows . a Bibiacer sees that the Z distant signal is down _ and knows that’ the at the pera or full speed. A “home” sig- ~ nal is so called because it is nearest “home”; or in ee. block the train seeks to enter wrong. is down without the home being correspond- ingly clear. This shows matic train control is designed to stop the engineer safely at home signal in such a case _ the front of the engine. Popular Science Montily these much-needed contrivances, the Govern- ment has for several years maintained a corps of trained investigators who will go to almost any part of the country and test out free of charge any invention of the kind that gives promise of being worth while. Moreover they will make an authoritative report on its merits, if it proves worthy of attention. This corps has given much practical aid to inventors, and done much through suggestions to standardize and improve the inventions being put out. At present we are on the road to a practical train-stop. To illustrate the general train-stop situation specifically, we will show how one of the best train-stops operates. Let us take the type recently perfected by Jean F. Webb, Jr., of New York city. As the pictures on page 438 show, the apparatus is affixed to the buffer-beam at Other inventors attach their stop to the tender, or even beneath the cab. Some have attempted to locate most of the apparatus along the roadway and have it struck by a projection on the engine as the latter goes by. This, however, seems to be a wrong plan in most cases, since the great force of such a broad- side impact may result in breaking the appa- ratus to pieces. The ramp principle Mr. Webb uses is begin- ning to be recognized as the most satisfactory out of the number of alternatives. As the engine and train approach a block signal, the shoe part of the apparatus runs up a short piece of inclined rail, or T-iron, say thirty feet long. This piece of inclined rail is called a ‘“‘ramp.’’ As the shoe rides up over the ramp it opens the air valve on sl = “Po Railroad_No.\ 4 at; 2 \ 54 Rai No.4 lz ft Railroad 2 The complication of signals an engineer — y encounters in an ordinary railroad Vie yard which covers an area about two miles long and about one and ene- quarter mile wide. All tracks are single tracks; the parallel lines represent rails ip r Showing more compli- cated signals than the preceding. Engineer has whistled for side- track. Towerman ac- cordingly gave it to him, at the same time lowering the lower of the two arms at the home signal—which in- dicates that everything is ready for the train to proceed to side track — Still more complicated signals, showing what mixed up propositions an engineer encounters. He must read the sig- nals almost instantly and correctly or cause trouble for himself and train. Here signals mean main line is closed but sidetrack is open 438 the train in the manner explained in the Should the block ahead be clear, electric current comes off of the ramp illustration. at the same time that the latter is causing the air valve to open. This current works the electro- magnet shown, and sets a catch or bolt so that the shoe in descending auto- © matically closes the valve again, thus letting the train proceed unhindered. If the block ahead is not clear, there is no electric current at the ramp, the electromagnet therefore can not set the bolt, and the result is that the shoe and its plunger descend off the ramp _ without closing the valve in the process. The latter therefore remains open where it has been pushed, the brakes become set, and the train comes to a halt. How the electric cur- rent gets into the ramp to perform this setting of the bolt feat is too long a story to tell here. The current comes from a roadside battery which is a part of, or at least under the control of, the regular block-signaling system anditssignalarms. This establishes the needed co- operation between the signals and the auto- matic stop, and causes the stop to enforce the signal’s mandates, which is the end desired. Be- sides opening the air valve at least momen- tarily at every ramp, whether it is needed or not,. Mr. Webb’s appa- ratus sounds a whistle in the cab at the same time, confirming the other indi- cations. A governor also comes into action, pre- venting the engineer from going beyond a certain speed in a danger zone. Popular Science. Monthly New Answers to the Query, .‘‘Why Does a Cat Have a Tail?”’ a 74 —— ST Bolt. inoperative position The Webb device. When the engine should stop, the shoe rides up an inclined rail and actuates the brake mechanism 1 Operating 1 position Air brake shaft The shoe is here shown sliding downward and off the ramp, closing the air valve so the train can proceed in safety TS question having arisen, ‘‘Why does the cat have a tail ?”” the scientists seem willing to answer it with another question, ‘How would the cat look without a tail?’ No one can gain- say the fact that the tail is a valuable ornament. The cat without one is a sorry sight. But there are those who maintain that the tail serves the cat as a sort of gyroscope, balancing the body in leaping. This cannot be wholly true, for Manx cats get along very well without tails, and rabbits . have no use for them at all. Yet both the Manx cats and rabbits do a lot of leaping. After all it looks as if the tail is only an ornament, unless it is a kind of safety valve for expression in exciting times. Of course there are in- stances where the tail serves some purpose other than that of art. The monkey finds his useful as a sort of fifth leg; the horse uses his as a fly-swatter, as does the lion; the crocodile uses his for swimming, as do the seal and the turtle and other aquatic creatures; and the rattle- snake uses his for warn- ing enemies. According to W. D. Matthews, of _ the American Museum of Natural History, the tail was a necessary organ for the aquatic and am- phibious ancestors from which the higher animals are descended. When they took to terrestrial life and to walking on all fours, the tail became more or less superfluous. ~ BS ee _ are different if the airplane is beyond ye Pivot Sliding head Tension spring ae . The instant the aviatoristhrown out of his nor- . mal position, the - spring is released chute stick is ’ -straightened out automatically VERY ship car- ries its cork- jackets for pas- sengers. Is there no life-preserver which the crew of an aircraft can don in an emergency? The parachute at once suggests itself. Pre- arranged parachute Aine if leaps have often been , \ : made from airplanes. Conditions SY control, owing to the quickness with which disaster overtakes one in the air. There is no time to think. Then there is the difficulty of getting clear of an over- turned machine which itself drops like a stone. The critical point is the automatic unfolding of the parachute in the air through the initial drop itself, which demands that it must be just slightly unfolded below so as to be ready to catch the air. Kaja P. Togstad, in inventing a para- chute that would remain efficient in an accident, has evidently realized these difficulties and taken a step in the right direction. He would throw a parachute automatically into the correct opening position by mechanical means. As the picture shows, he supplies his parachute with a central stick like an umbrella’s. _ A Parachute Life-Preserver for Aeronauts It is ready for any emergency and acts automatically—says the inventor The stick doubles on itself in the middle, so that the whole contrivance can be carried on ‘the aviator’s back. A coiled spring automatically unfolds and straightens the stick the moment: the aviator leaves his normal position in the machine. The device would, however, seem feasi- ble only if the parachute was no larger than an umbrella. Although so small a parachute would somewhat retard the » fall, there would be ‘} scant comfort for the » bereaved family in _ knowing that the avia- tor was picked up after a fall of nine thousand feet with only a broken neck and not with every bone shattered as usual. The place of this. umbrella-like con- In most acci- dents, the avia- pect Fans Taat trivance might conceiv- here lies. the ably be taken by a value of this de- vice, when coup- led with an effi- cient parachute really efficient para- chute (of twenty-two feet minimum diame- _ ter) made of cloth and ropes so thin, yet strong, that it might be folded into a small enough bundle at the end of the stick which by the same mechanism, might be thrown instantly and automati- cally into the proper position to catch the air and open promptly. In use, the parachute device is fastened to a corset-like belt which the aviator dons when preparing to make his ascent. The swinging staff section is held down by means of lashings, which allow the wearer to walk about in the machine so long as the parachute is collapsed. After the aviator takes his place in the seat of the airplane he releases the lashings so that the staff will be free to operate but will be held back against the seat and prevented from action unless the aviator is thrown out or moves suddenly from his seat. 439 Standardizing the Die-Sinker An automatic machine which can produce fifteen dies in the time formerly required to make one By Herbert F. Sherwood \ , THEN you have four hundred drop forgers to keep busy and wish to turn out from 200,000 to 250,000 forgings in the course of every twenty-four hours, you begin to take thought as to how you can save in the necessary opera- tions. Do any pieces require three different manipulations when two will answer? Are there any machines, or can any be invented to reduce hand work? One of the necessary details of making drop forgings, of course, is that of producing the dies. The pattern’s the thing. It must be exactly right, cut to the one- thousandth part of an inch of the desired dimensions. In making rifles the dies must fit so closely together when the hammer comes — ‘down that the ‘‘flash’’— in other words, the excess metal which spreads out around the forging between the two dies, will be like paper for thin- ness. The thinner the flash, within reason, the greater the production from the trimming presses which later cut off the halo of metal. In a Bridgeport, Conn., plant a way has been worked out not only of standard- izing the process of making dies to serve as models, but of adapting the principle used in copying statues and making jewelers’ dies by ma- chinery, to the sinking of larger dies. In the making of a standardized article, such as a bayonet, however, and where consider- able numbers of large dies are required, it has been demonstrated that it is practicable and economical to plan out in advance the different operations required in the making of a given die and specify them on a card of directions accompanying the block of metal from which the die is to be made. MOVABLE. CRANE TRACK ‘The outline of the desired die is drawn . -upon the coppered surface of the block E SPRING PENCIL-LIKE = gn OL By means of this machine one die can be made in eight hours. One man can supervise three machines and the directions specify what cuts shall be made, and the exact depths which shall be given to them. The cutting tools that shall be used are also named. One work- man may not necessarily perform all of the work. Some of it may not require an expert’s attention. The model completed, it is put into a machine which carries also an uncut block. This machine is equipped with two arms connected so that they will work like a pantograph. At the end of one of these arms is a pencil-like stylus of metal whose point, pressed against the model, follows every indentation in and out. To the other arm is attached another stylus, also about the diameter and shape of a carefully sharpened pencil. This one, made of very hard steel, revolves so rap- idly and smoothly that its cutting.edges can- ate not -be seen. As the DRILL upper stylus moves up and down across the face of the model in parallel vertical lines five one-thousandths of an inch apart, the fast flying pencil-like stylus below follows suit across the uncut surface of the lower block. With the same undeviating evenness of speed that characterizes the movement of the earth around the sun, it engraves a reproduction of the model. Ordinarily, by the old methods it would require one man’s time for from thirty-six to forty hours to produce the die. By means of this machine, the same work can be done in eight hours, and one man can supervise three machines. In this way fifteen dies can be produced by him in the same length of time which was ~ formerly required for one. Owing to the more automatic character of the work, a less experienced man can be employed for this part of the operation at less cost. ~ US COMPLETED | ue MODEL Zs 440 An Easily Adjusted Ball-and-Socket Detector-Stand ~-DETECTOR-STAND capable of -es- pecially easy adjustment, on account of the ball-and-socket arrangement of the movable arm, is illustrated herewith. The _ ball was taken from a butt-hinge; a bind- The ball-and-socket joint makes an easily adjusted detector for wireless apparatus ing-post was re-threaded to fit the stud attached to the ball, as shown. The socket is made from spring brass, and holes slightly smaller than the ball are drilled very near the ends. A tension-screw is fitted to the socket, which is three-quarters of an inch long with a knurled nut for easy turning. The mineral holder is a U-shaped piece of quarter-inch brass rod flattened at the bottom. Near the end of one leg a hole is tapped with an 8/32 tap and an 8/32 thread is also tapped in the bottom of the clamp so that it may be fastened to the base. The base may be taken from an old spark- gap or cut out of fiber or hard rubber and drilled to suit. It should be about 2 in. by 4in. The arm is made of %-in. brass rod 3 in. long; threaded 8/32 at each end. A binding-post may be mounted on it to carry the ‘‘cat-whisker’’ wire or mandolin- string, or nuts may be used on the arm end for clamping the same as a binding post.—FRANcIS W. NUNENMACHER. Amateur 4) Electrician y And Wireless Operator A High Tension Audion Battery Made of Medicine Vials HEN using audion or similar tubes, a battery giving from 30 to 40 volts is necessary. Such a battery made up of small flashlight dry-cells is most convenient but costs as much or more than the tube itself. Dry-cells also have what is known as ‘‘shelf life.’”’ This means that they de- teriorate even when standing idle (on the shelf evidently). Ina year’s time, more or . less, they will have lost their strength and their voltage and current will be near zero. As the high tension current consumed by the audion tube is extremely small, a *bat- tery may be mad «1p of very small storage cells, when a direct or alternating lighting current is available for charging them. With alternating current, however, a suit- able rectifier must be used. The battery cells may consist of small medicine vials with strips of roughened lead for plates. Such a battery is shown in the illustration, mounted directly back of the panel holding the tube and voltage-regulating switch. The vials are conveniently mounted in a row between two wooden cleats so that they will not topple over. Small wires are led from the switchpoints and soldered to the tops of the lead strips. The lead strips Han TAAGTAUAAAID Cells of battery made up of small medicine bottles with strips of lead for the plates should not reach to the bottom of the vials. A drop or two of light oil on top of the electrolyte will tend to prevent acid fumes from arising and tarnishing parts of the apparatus. When charging with 110-volt 441 442 alternating current, an aluminum plate rectifier! must be used in series with the battery, together with a small lamp or other suitable resistance. The aluminum plate of the rectifier may consist of a small alumi- A type of rectifier used with the battery for charging it from an alternating current num wire with its point just dipping into the rectifier electrolyte. As the battery is small, the charging current must also be small. A gentle bubbling at the plates is _ sufficient. This battery does not hold its charge very long but it is a simple matter to charge it each time before use, as a double throw switch will change the current to the charging circuit or to the apparatus . quickly.—R. V. WILsoNn. Wireless Signals Transmitted by Telephone HE diagram shows how I enabled my friend who had no wireless outfit to listen in on my set. I installed a one-wire telephone line between our homes, which are about 400 ft. apart. Much to my surprise this in- creased the strength of the signals. TELEPHONE LINE sat “ t Wiring diagram of the telephone line show- ing its connection with the wireless set As an additional pleasure we were able to talk over the telephone while wireless mes- sages were coming in.—C. WILTSEE TUFTs. Popular Science Monthly An Effective Method for Recharging Dry Cells HAT I have found to be the most effective method for recharging dry cells consists in making over the construc- tion, of the cell and placing it into some container. Sucha container may easily be made from a hollow tile such as is used in building construction. These tiles are cut to the height of a dry cell by a hammer and chisel. The tile is then stood upright on’a flat board and enough concrete is ‘poured in to fill the bottom of the tile an inch deep. After the concrete has set, it is coated with a thin layer of melted / paraffin which is then allowed to cool. The bottom of the dry cell is thén knocked off and the ‘agi compounds, with the exception of the sealing compound, are then taken out. A number of holes are then punched in the cell, and it with its carbon is then immersed in an ‘‘active”’ solution poured into the tile. This solution is made of sal ammoniac and soft or rain water in the proportion of 4 oz. of sal ammoniac to I qt. of water. —TuHomAs W. BENSON. Running Bell-Wires Through Walls with an Umbrella-Rib Bodkin N umbrella rib may be made to do excellent service in running electric bell-wires. Such a rib is not a great deal larger than the diameter of the bell-wire, consequently it DRY CELL HOLLOW TILE ft 2 . s can be run tk 7 Umbrella rib through a small — way, |B : fall W hole. The wire “Il wt is stripped of its = i covering for a Aw aN i We Wa! short distance re 1 HY Loop — and threaded through the aes little loop near ; “ee Rp? the end of the ) Elgtic bell wis inetd rib. The wire is then pressed snugly into the trough of the rib, which can be moved around while searching for the opening without disturb- ing the wire. The ball on the end of the rib facilitates its easy passage through the opening.—JAMES M. KANE. Fighting the Big Guns with Wireless Thrilling adventures of the airmen while signaling the range to the artillery gunners By Captain A. P. Corcoran, Late of the British Army probably at one time or another tried to operate an instrument of your own. And to do so, you have probably repaired to the seclusion of your own room, well removed from outer disturbances. Even then you have probably found difficulty in getting signals. Perhaps a cat howled, or your sister put her inconsiderate head in at the door, and diverted your attention for a moment. You know how little it takes to upset the accuracy of an operator. And now, if you are to get an adequate idea of the task of the wireless man in this war you will have to try to put yourself for the moment in his place. You will have to imagine yourself not safely housed, but up six thousand feet in the air, with only a few pounds of wood and a few yards of canvas between you and a very certain death. You will have to imagine that all round you dozens of shrapnel shells are bursting, and that to right and left of you are enemy airplanes, hot on the trail of yourcar. Through the midst of this sea of T you are interested in wireless, you have The airman signals to the gunners the range necessary to make a hit, after seeing where a shell has dropped and exploded at or near the enemy’s lines. When a hitthas been made he glides away peril you are piloting your ship, with one eye on the dangers immediately threatening you; another on the ground for the information you are seeking; and still a little attention centered on the tiny wireless set, without which all your work would be in vain. You have heard the airplane pictur- esquely described as the “eyes of the army.” That is a very accurate descrip- tion of the part it plays. It is through the airplane that the artillery gets an effective range on the enemy batteries, or locates the enemy ammunition dumps, or a light field battery, or convoys, etc. It is through the wireless set attached to the airplane that the firing is directed. Without the wireless, the airplane would be of little use. There are various types of machines used in the war, but the two principal ones are the Hugh battleplane and the small Bristol biplane, the latter being used for scouting work alone. But no matter what the car, the wireless set is the same. It is the Wil- son set. 443 4b As you might imagine, the set is small and extremely light. It comprises just a 4-in. spark coil, a manipulating key, a small fixed oil condenser, contained in a steel box, and an aerial coil. This helix or aerial coil is not made of the usual copper tubing, bound on a wooden frame. It is made of several turns of soft flexible insulated wire wound round a piece of wood and kept se- curely in place by two cross-pieces of wood. The lay-out of the appa- ratus is not ‘necessarily uniform. Usually the airman shifts it to suit his own con- venience, but as a rule its positionis Popular Seience Monthly make, it is hard enough to breathe without wasting effort in trying to hear. Besides, even if the rush of air would permit you to collect your senses, there is still the propeller to be reckoned with. The noise of this close to the ear can be compared only with that of a forty-coach express train tearing at top speed through a tunnel. But suppose it were possible to perfect an instrument that could make itself heard against these handicaps, of what use would it be, when com- pleted? Under the circum- stances in which the airman fights, in- structions i ee Oil condenser | this: The condenser and coil are placed under the seat; the aerial coil is made fast to the framework near the operator. The key is on a small wooden shelf fixed, to the side of the seat, and sometimes it is placed on a partition in front of it. In the case of the small scouting ma- chines, the aerial is fixed on the top of the wings and runs round the edge, while the lead-in wire is brought in from the center. Then the earth or ground wire hangs over the side of the plane to the same length and capacity as the aerial. In these cars, of course, the pilot and operator are identical. Only one man goes up. In the big battleplanes, the aerial is in much the same position. It is fixed to the top.of the top plane. But the ground wire is arranged differently from that on the scout machines. Here it is attached to the bottom of the bottom plane. In other words, there is an upper and lower capacity, just as in the Lodge-Muirhead system. Now in these planes the operator is the observer. He sits in front of the pilot. But, in case he should be shot or in any way incapacitated, there is a manipulating key in the pilot’s pit joined in parallel to that in the observer’s chair, so that either man is in a position to operate. There is, of course, no receiving ap- paratus. So far it has not been found necessary. For if you are traveling at the rate of 120 or 130 miles an hour, which is the speed many of these planes are able to The operator’s set comprises a four-inch spark coil, a manipu- lating key, and a small fixed oil condenser, all in a steel box from the earth are of nousetohim. He is the one man in the war who fights as an individual. Once he has left the earth with general orders as to the object of his flight, he takes advice and instruction from noone. ‘The thoroughness of his work, the chances of his safety are matters left entirely to himself. They depend solely on individual initiative. Let me take you with him on a trip, typical of one he might make any morning that is clear enough to let him see what is happening on earth. Aerial coil~ baie 3. 8 unt tl...,Oil condenser The condenser: and coil are placed under the seat. and the key on a shelf near by The artillery has got the range roughly and set their sights accordingly. The air- man ascends, and is soon soaring over the enemy lines.. Now he is in sight of the target. He signals ‘‘G’’ back to the artillery. That means ‘““Go! Commence firing.” They fire. In a couple of seconds there ascends a streak of smoke. To his eye it is no bigger than the puff of a cigarette, but it Popular Science Monthly tells him that the shots from his artillery are not reaching the target. “T) 300, L~ 100,” he signals. That ‘means, ‘Lower the range 300 yards and _ come 100 yards to the left.” A few more seconds, and there is another ti cit of white smoke. Again it is short of JSML_Aerial coil ‘the target. WIL “U 100, R 50,” he signals; mean- ing, ‘‘Raise the range a_ hundred yards and shift it fifty to the right.” Again he waits, and this time he has his reward. Now _the puff comes from exactly the right spot. “H,” he signals back, repeating the letter ; several times. It means, “Hit.” The artillery have got the range. Sometimes they get it more casily than this. But often they take much longer. And the longer they take, of course, the more perilous for him. For meantime, naturally, he himself has become a target. Shells from the anti-aircraft guns have been exploding to right and left of him, but he manages to soar away from these. Then something worse looms up. The enemy airforce is preparing to meet him. They are leaving the ground. He knows they will soon be on him. Unless he hastily disappears from the scene there is soon in progress one of those great duels in the air—but that is another story. The aerial is made of copper tubing Down with the Old-Time School Bell! Supplant It With Wireless NE of the technical high schools in a large city has worked a new variation on that old-time institution—the public school bell. Time was when brassy- sounding bells used to adorn every school- house steeple in the land. In the larger cities these have retired in favor of a system of electric gongs, one in every room. This system is useful for calling classes during a day as well as for gathering the whole flock of pupils together at nine in the morning—this last being about the sole function the earlier steeple bells could perform. But this school in question goes a step farther than even the electric gongs, connected as the gongs are with networks of wires, annunciators, time-clocks and the like. It is done here by wireless. 4A5 The change came about through the fact that the school long ago became too big for the original building, even though it was large and well equipped. Since then . surplus classes have been held in such buildings in the neighborhood as could be secured. How to call and adjourn simul- taneously the successive classes throughout the day in all these buildings therefore became a problem. The principal sug- gested that it be done by wireless, and the school’s class in radio-telegraphy com- pleted the system, the essentials of which are shown in the diagram. The sending end of the system is unusual only in that a small rotary converter is used to convert direct current—the only supply available—to alternating, for the trans- former. Had alternating current been available this could have, of course, been hooked on at the same place as that of the converter, and the system would have worked as well. The receiving circuit uses a coherer made of metal filings in a small glass tube in the usual way. Interposed between the coherer and the bells, which do the calling of classes, is a pony relay of the kind often used on ordinary railroad telegraph circuits. The object in using a relay is that its high resistance takes less current than the bells would if connected directly to the coherer. When heavy currents go through a coherer they cause the filings to stick together permanently, or nearly so, rendering them hard or prac- Instruments in use by a technical high school for calling the classes by wireless tically impossible to decohere. The co- herer, as is evident from the diagram, is placed in close proximity to theclapper on one of the bells. Thus the clapper automatically decoheres the coherer, doing away with any special apparatus for that purpose. A one-kilowatt transformer sends out a wave sufficiently powerful to operate co- 446 herers and call bells of this type over a distance of several blocks, and of course over much longer ranges if the receiving apparatus be made carefully and adjusted with delicacy. Circuits of the simple type here used are likely to be very sensitive to Sending station Popular Science Monthly How to Make a Variable Condenser for Five Cents HIS condenser can be made at a cost of about five cents. First cut the plates out of cardboard, the thinner the better. Receiving station Transformer Aerial support Insulators ye Aerial wires a eS vat Primary ss ial Variable condenser Secondary Spark gap Ground ee Sending key. Alternating current emitted here (0) Rotary converter Prat WOvolt direct ¢ current supply static during summer months, passing thunder showers causing the bells to ring more or less continually, the frequency of the rings of course depending on the number, distance, and strength of the lightning discharges causing the static. But in such an event the system auto- matically becomes a storm detector, and that pleases youthful investigators all the more. Or, it affords an opportunity for experimenting with contrivances of one kind or another for doing away with the trouble caused by the static, and that in turn offers an alluring field for the exercise of ingenuity.—L. E. DARLING. A Binder for Water Colors and a Wood Filler ASEIN is a good binder for water colors, but as it contains alkali it is not safe to use with certain chemical pigments. In this case glue, or any adhesive that is neutral, may be used. Casein is easily dissolved in ammonia, caustic soda, potash or carbonate of soda, but a more economical alkali is quicklime, which does very well when the material is to be used in making a wood filler. Roughly speaking, one quart of quicklime is sufficient for four parts of casein. Simple Marconi Clapper on bel | coherer decoheres coherer as well : i _ |} asrings the bell Two cells of Es battery ie . Bell for calling deseo | lhwocen battery Ground connection The set-up of the apparatus and the connections as they were installed for calling the classes by wireless Then paste onto each sheet of cardboard a piece of tinfoil about 1/16 in. smaller all the way round, except at A on the rotary and B on the stationary plates, where the tin- foil should be continued out to the edge for a connection with lines. The tinfoil should be put on one side of the cardboard only, as the cardboard acts as the dielectric, as in Fig. 2. Washers can be used as_ separators. FIG.) STATIONARY, \ FOTARY ——% eae UATLUES STS UERR RL RE TRE TETI FIG2 The condenser plates are made of cardboard and tinfoil stuck together with shellac Five stationary and four rotary plates, six inches in diameter, using the so-called “shirt cardboard’? as the dielectric, will have a capacity of approximately .0005 microfarads.—RAYMOND RoorF. the increased demand for wireless | Toeverstor which has been created by the | : s A a ia e,. conditions arising from the declaration of war, the idea seems to prevail that a competent and useful telegrapher can be trained in a course extending over a few weeks of time. Nothing can be further from 3 the truth. The beginners, who are now radio operator is not only valueless the training of a radio telegraph taking up radio telegraphy for the first time, will have many months of study to carry through before they will be really competent. Until they have become thoroughly familiar with the code and LINE WIRE Wireless Work in Wartime.—Il. Learning the operating thoroughly and setting up a buzzer telegraph line By John L. Hogan, Jr. prepared it is unwise to place them in responsible positions. It is also unwise for the students to attempt to speed up their courses of training by extreme abridgment, in an attempt to learn ‘‘only the funda- mentals.’”” Thoroughness should be the watchword of every beginner; a little time spent in study of the important details will be more than repaid by the greater progress which will result as soon as the practical work is begun. This series of articles, which was begun in the August issue of the PorpUuLAR the basic principles © of radio telegraphy they will not be de- pendable; without dependability the but dangerous. It cannot be too strongly urged that A buzzer-set with must be complete and thorough and that it is utter folly to attempt to cover so exten- sive a subject so rapidly as to make its complete absorption an impossibility. The Study of Radio Operating Although the several branches of radio telegraphy involve a good deal of study, the work of learning it is probably one of the most interesting occupations that a person of scientific inclinations can find. There is a good future for well trained radio operators, both in wartime and in the days of peace. The number needed because of the present crisis is larger than normal, and more will be required from month to month. The trained operators who are now available will take care of the immediate needs, and those who are at present studying in the various telegraph and radio schools through- out the country will be utilized in the near future. The newest students will have their opportunities as soon as they secure their training, but until they are thoroughly Fig.5 its connections for sending messages from one room or place to another in learning to operate a key in wireless telegraphy SCIENCE MONTHLY, is designed to point out methods of study of radio- telegraphy which will result in. thor- ough training in .the shortest desir- able time. Only the most elemen- tary knowledge of electricity has been assumed, but even the skilled radio experimenter is likely to find some points discussed which are unfamiliar to him. The first article took up the commencement of the study of the Morse code, as a preliminary to telegraphy itself. The simplest subdivi- sions of the Morse alphabet, for aiding in memorizing the dot-and-dash symbols, were explained, and a description of key and buzzer practice was given. As soon as the student has learned to form the first three groups of letters correctly, as set forth last month, he should commence signaling practice with a companion who has progressed to about the same point in the study of telegraphy. TELEPHONE Setting Up a Buzzer Telegraph Line The first step in communication is to set up a buzzer telegraph line between two points which are so far apart that the telegraph itself is the only means of com- munication. If you put one end of the line in one room, and the other close by in 447 448 another part of tre nouse, there will always be the temptation to call from one “‘sta- tion’’ to the other and to make corrections in that way instead of depending strictly upon the Morse signals. Only by relying upon the line and Morse signals exclusively can the best practice be had. An excellent system _ of connections for a practice line is shown in Fig. 5. For each station there are needed a buzzer, dry cells, telegraph key, and telephones. Almost any sort of buzzer or telephones will do, though it is better to get a buzzer which gives a high musical tone and to use tele- phones of the usual. wireless type. The small buzzers which can be purchased from any electrical sup- ' Popular Science Monthly receivers in series between terminals I anae 3 of the buzzer. If the adjustments and wiring are correct the buzzer will operate whenever the key is pressed, and the tone of the buzzer will be reproduced loudly in the telephone receivers. If the tone is so loud that it becomes annoying, a resistance of several hundred ohms may be .connected across the telephones as shown in the left hand station of Fig. 5. If this resistance is variable, as it is in a potentiometer used with radio receivers, the loudness of the sound in the telephone may be made any- thing desired by adjusting the resistance so that any chosen portion of the line current will be shunted around the winding i in the “by-pass” circuit. ply store have fairly Assuming that high tones and are both stations have very good. There been set up and are special ‘‘wire- adjusted to operate less’’ test buzzers : fH] «properly, it is only made, which have HR gascseas cecteece ett} «necessary to con- three connection ve ti att A Wh Ht Toot nect the outer ter- ce Rie asneesedel Figs Te {iy [ minals of the two _ points and which on are designed to give avery high and clear tone of about the same sound as that produced by a modern radio-telegraph station. This is the best type to buy. The preferred tele- phones are of high resistance (about 2000 ohms total) and consist of two ‘‘watch- case’”’ earpieces mounted upon a headband which automatically holds them in place and so leaves both hands of the operator free for sending, writing out the message being received, or adjusting his apparatus. An advantage of buying both the buzzer and the telephone of the sorts used in regular wireless telegraph work is that both may be used later on when radio-telegraphy itself is taken up. Wiring the Two Stations The diagram, Fig. 5, shows how the two buzzer telegraph stations are to be con- nected. First the dry cells and the key are connected in series across the two ordinary terminals of the buzzer, marked 1 and 2 in: the figure.. Then the binding post I is con- nected to earth, and a wire is attached to the contact post near the buzzer armature, marked 3 in the figure. This wire is con- nected with one terminal of the telephones. To make sure that everything is in good shape at either station, the remaining terminal of the telephone may be con- nected with the ground, so placing the “In answering a call at the other station ac- knowledgment of the call is sent in return telephones by means of a line wire. This line wire may be of almost any kind since it carries very little current. Any copper wire may be strung from one station to the other; it need not be larger than No. 30, and does not require careful insulation unless the distance is large. When the two stations are set up completely, as in Fig. 5, pressure of either key should result in a corresponding clear signal tone in both telephones. If it does not work out in this — way, go over the circuits in detail and be sure that they are correctly connected and sufficiently well insulated. The earth or ground connection may be made by wrap- ping a bare wire around a scraped water or gas pipe, or a steam radiator. For con- venience the ground lines may be discarded and a second line run between posts 3 of the two buzzers. The diagram shows the variable shunting resistance at only the left-hand station; obviously the same plan may be used at both ends if the signals are too loud. The incoming signals are likely to be somewhat weaker than those made by the buzzer at the home station when sending, but if the line wire is of sufficient size and well enough © insulated this difference in intensity should cause no trouble. Under some particularly poor conditions it may be found necessary to shunt the telephones while sending and to use them directly in the circuit (or shunted by an extremely high resistance) while receiving. How the Call Signals Are Made In taking up code practice over such a _ telegraph line, the usual wireless methods of _ ealling and signing should be followed. _ Since every radio telegraph station has certain identifying call-letters assigned to it _ by the Government, the two practice _ stations should select call letters. Let us _ suppose that the left-hand station chooses the call signal KSW and the right-hand station KUR; these groups of letters will designate the corresponding station and that one only. Having arranged the line and apparatus so that every pressure of the sending key at either station may be heard as a correspond- ing short or long buzz or tone in the tele- phones at the other, the sending of messages may be begun. The time for the first trial having been set, both students should be at their instruments, and listening to the telephones. Let us assume that it has been arranged that KUR, the right-hand station of Fig. 5, shall signal first. The operator there will follow the International calling method and first send the “‘atten- tion” signal, dash-dot-dash-dot-dash, two or three times as shown in Fig.6. Thisisa general signal which precedes transmission of radio messages, and is merely to catch the attention of the receiving operator. Hav- ing signaled attention, the call letters of the station desired are now formed three times in succession: KSW KSW KSW, as is also shown in Fig. 6. This part of the call serves to notify the operator at KSW that he is wanted by some other station. The - next part of the call is the French word “de,” meaning from, which is immediately followed by the thrice repeated call letters of the sending station: KUR KUR KUR. At the close of this signature, which indicates the name of the station from which the call is sent out, the operator makes the finish signal, dot-dash-dot-dash- dot and then signals the letter ‘‘K.” These two characters used in this way mean: “I have finished sending and will listen immediately. Please reply.”’ Answering the Call Signal The operator at the other station, upon hearing this call, realizes that KUR desires to open communication with him. There- foré he sends an acknowledgment of the call Popular Science Monthly 449 signal and an invitation to transmit, in accordance with Fig. 7. This consists of the attention signal sent twice or three times, the signal letters of the calling station (KUR) sent three times, the word “de’’ (from), his own signal letters (KSW) three times, ‘‘K’”’ several times (meaning “go ahead’’), and the finish signal. The first operator, at KUR, then knows that the second station KSW is ready to receive the messages to be sent, and proceeds to transmit them. In the course of a message the sending operator occasionally makes a mistake; noting this, he at once stops tijt tii Fig? rare tii The usual wireless signaling should be taken up in code practice sending and signals a question mark dot- dot-dash-dash-dot-dot, then repeats the previous word correctly and continues with his message. If a receiving operator fails to receive the entire message correctly, in his following period of sending he requests a repetition of the words missed. This is usually done by sending the last word received correctly and following it by several question marks (dot-dot-dash-dash- dot-dot) and the next word correctly received. If the receiving operator gets correctly everything sent to him, he signals “R” (meaning ‘Received Correctly’’) sev- eral times at the beginning of his next period of transmission. Thus complete conversations are carried on and acknowl- edged or corrected. The detailed form of sending commercial messages is somewhat more complicated, but the simpler method just outlined will prove ample for practice work. The practice messages should at first be made up of words including only the letters of the first three groups of Fig. 2, in last month’s article. As soon as all of these letters are perfectly familiar and easily recognized when their Morse sounds are heard, the remainder of the alphabet may be memorized and worked into the code 450 and message practice, sending the words most used in army practice first, then others later as the operator becomes more pro- ficient. Careful Sending Is Essential In sending, strive always to make care- fully and accurately timed dots, dashes and spaces. Give particular attention to the length of spaces between letters and between words, as explained last month. The receiving operator will not be able to write down your letters correctly unless you form them correctly, and without careful sending many serious errors may result. In calling, for example, be sure not to run the call-signal letters together. Each time the call is sent, pause for a word-space before repeating it; otherwise instead of hearing three well separated groups of letters (KSW KSW KSW) the receiving operator will get a jumble of nine letters (KSW KSWKSW) and will not be able to tell whether your call is KWS, WSK or SKW. Similarly, keep the ‘‘de’’ well separated from the call letters themselves, and the “Attention” and “Finish” signals sharp and distinct. Beware especially of making the “Attention” signal sound like KA, or the “Finish” signal like AR, by introducing an extra dot space that should not be there at all. When copying messages sent from an- other station, even in the very beginning of practice, wait till a single letter is com- pleted and then write down that letter in script. Never write out the dots and dashes themselves; the letters-should be transmitted to you sufficiently slowly, and with enough space between each pair of them, for you to write out the letters them- selves. As you become more and more skilled you will find it possible to carry an - entire word or several words in your mind before writing them down. To do this, however, requires much practice and an excellent familiarity with the Morse code. The two-station practice method de- scribed in this article, according to which two students progress together, is far better than studying for Morse reading by the use of an automatic sending machine alone. The ideal method, however, combines the two. In the next article some further points to be considered in operating will be explained, together with an arrangement for combining several stations and an automatic sender on a practice buzzer telegraph line. Popular Science Monthly Relieving the Strains on an Aerial Fastened to a Tree HE amateur who has his aerials sus- pended between a house and a tree PULLEY / / — ASST i\ A tension spring in the holding rope of an aerial to relieve strains on the wires HEAVY SPRING ae. iy, t} “~~ CHECK ROPE! is often bothered by the breaking of the wires. This is usually caused by the tree swaying and pulling on the aerial. The sudden strain so exerted may be lessened by attach- ing a spring to the aerial rope as shown in the sketch. The spring stretches when the strain becomes greater than the wires will stand with safety. A check rope should be attached to the spring so that if the spring should accidently break the aerial will not fall—Paut L. KEATING. AA An Inexpensive and Quickly Made Detector ERE is a detector that can be built in half an hour. It is simple to make and easily adjusted. Upon a base 3% in. square, mount two spring connectors on top of small blocks at the sides of the base, as shown. The spring connectors may be taken from an old dry-cell._ A piece of cat-whisker wire—mandolin E string—is soldered to a small rod which i is inserted in the loop of one of the spring connectors. The end of the rod is threaded and provided A detector made of scrap material mounted on a wood base with wire connections beneath with a small insulating handle. The other spring connector holds a piece of No. 14 copper wire, to which is soldered the cup of an old dry-cell.—E. F. JASPErRs. ee Tee ee eee. aS wae ee a ee _ to be reasonably successful. 2 Popular Science Monthly _ Sustained Wave Telegraphy Between the United States and Germany EFORE 1913 there was no direct means ) of communication between Germany 4 and the United States, except by submarine cables. The Allies cut these cables im- mediately war was declared. Between that time and our own break with Germany, communication was established by two of A the most important pairs of wireless sta- tions ever known. And now that all active amateur and Cc FIG. 4 . Curve representing progressive values of the current generated by a radio alternator semi-professional work has been discon- tinued, this ought to be just the time for our friends to study the ‘‘workings’’ of these great stations. | The quenched singing spark systems, _ which were used for almost all radio work at the time these stations were erected, were first tried at Sayville, but proved entirely too feeble for the distance that had now to be covered, about 4000 miles. The sustained-wave system was therefore installed at Sayville, and it was found Exceedingly high frequency sustained alternating cur- rents were used in all four stations. For generating these, the stations at Eilvese (Germany) and Tuckerton (New Jersey) used the Goldschmidt ‘‘reflection’’ system, while those at Nauen (Germany) and Sayville (Long Island) used the Arco-Joly “multiplication’”’ system. The secret of the success of sustained- wave telegraphy lies in the fact that high frequency alternating currents—that is, the currents which go through many changes in direction in a second—are better radi- ators of energy from the sending sta- tion, while they also enable the receiving instruments to respond more strongly. As an alternating current generator re- _ volves, the strength of the electromotive force it produces varies as shown in Fig. 1. The strength of the electromotive force first increases until it reaches its maximum : 451 as shown by AB. It then decreases and finally becomes negative, reaching a maxi- mum negative value CD. It then reduces to zero again and becomes positive in value once more. By greatly increasing the speed of the generator or by increasing its number of poles it is possible to increase greatly the number of times the electro- motive changes in direction per second, and in this way, to increase greatly the radiation efficiency of a station. However, due to the fact that a machine cannot easily be made sufficiently strong in the one case and that the electrical efficiency may be too greatly reduced in the other case, this simple machine method was not used for these high power stations. The transformer methods of Goldschmidt or of Joly were therefore adopted, rather than the radio frequency dynamo of Fessenden and Alexanderson, used so extensively be- fore the war. The Goldschmidt system depends on the phenomenon called ‘‘reflection.’’ That is, the currents set up in the rotating part of the alternator (the rotor) can be ‘‘reflected’”’ back into the stationary part of an alterna- tor (the stator) so that the frequency of the original rotor current is increased to double the original. This can be made to take place by a suitable electrical connec- tion on the stator. Again, the induced current set up in this manner in the stator can be “reflected’’ back into the rotor. The frequency of this new current last set up will be increased to three times the original frequency. Finally, on reflecting FIG.2 Goldschmidt “‘reflection”’ alternator for quad- rupling the frequency of the original current this once more into the stator, the resulting current frequency will be once more in- creased, and to four times the fundamental. This is the current that was used in the antenna. 452 Alternating current is supplied by the generator G to the stator S of the Gold- schmidt alternator through the choke-coils A and the interrupting key K, as shown in Fig. 2. As the alternator is revolved by an auxiliary motor, the current set up in the rotor R is made very large by connecting the circuit DEF to the rotor so that the impedance, that is, the apparent resistance, to the current is made very small and the current made correspondingly ail FIG.3 One of the two frequency-doubling trans- formers of the Arco-Joly sending system large. The current is then reflected back into the stator as explained before, and the new current of double the original fre- quency is also provided with the tuned electrical path CL so that the impedance for it is also very small. Reflecting the current again into the rotor gives an- other current of three times the original frequency. This too is provided with a circuit of very small impedance, which allows the current to become comparatively large. The last reflection takes place from the rotor to the stator and it is this current that was used in the antenna. To accom- plish this, the antenna was connected to J and the ground was connected to J, as shown in the diagram; the loading coil B and the condenser C having been adjusted until the antenna was tuned to agree with the last reflected frequency. In this manner, currents which have the high frequency of 60,000—or 60,000 cycles of changes in direction per second—were readily obtained. The alternator was driven at a speed of nearly 10,000 revolu- tions per minute. The best results were found to be obtained on reflecting the cur- rents four successive times. ‘Theoretically, there is no limit to the number of times they may be reflected, but practically on reflect- ing them more than four times, the electrical and magnetic losses become excessive. Popular Science Monthly The Arco-Joly system uses a number of separate transformers so constructed that the frequency of the initial current is doubled every time it goes through a transformer. The construction of the separate transformers is as shown in Fig. 3. The transformer has two independent cores and an auxiliary circuit K, K’ supplying a direct current, which is sufficiently large nearly to saturate both of them magnetical- ly. The initial current is supplied to the primaries P and P’ of the transformers by the alternator G and the curve represent- ing its strength is an ordinary sine curve as shown by ABCD in Fig. 4. The capacity C and the inductance L are made of such values that the impedance of the circuit CLP’P is very small. .This causes the current in that circuit to become correspondingly large. On account of the manner in which the auxiliary winding K is connected, as the initial current passes through the stage shown by AB in Fig. 4, — the increased magnetization of core WN amounts to practically nothing. This is because the core is already saturated by the auxiliary direct current and also because the winding of P is such as to make it tend to add to the already saturated flux. In N’, however, due to the fact that winding K’ is in the reversed direction to that of K the current in P’ tends to decrease the total flux in the core N’. This can readily be done, and as the flux diminishes in ; strength, the change in flux induces an electromotive force in A B E ‘ F 6 H FIG.4 Curve showing how the first transformer ° makes the original current uni-directional the secondary winding S’. The result is the secondary current roughly represented by EF in Fig. 4. As the initial current reverses in direction, as shown by CD in the same illustration, it is evident that the phenomena in the core N. and WN’ are Popular Science Monthly _ reversed also, that is A the flux in core N is _ diminished and an electromotive force is induced in the secondary windings S, while _ the flux in core N’ remains practically the same and no E. M. F. is induced in the winding S’. Due now to the manner in which the secondaries are connected to- gether, the last induced E. M. F. produces a current through the secondary circuit in the same direction as that produced by the first E. M. F., giving the current represented by GH. As this is repeated over and over again, many times in a second, the second- ary current obtained goes through twice as many cycles as the initial current and - it is therefore of twice the frequency of the initial current. The new current is now led into an exactly similar transformer and its fre- quency is again doubled, giving a current which is now of a frequency four times that of the initial current. In the Arco- Joly system as used at Sayville, Long Island, the generator supplied a frequency of about 8,000 cycles per second, so that the frequency of the current supplied to the antenna was 32,000, which corresponded toa9,400 meter wavelength. The electrical and magnetic losses were kept down by making the cores of very thin iron sheets, which were insulated from each other, and by making the windings and connecting wires of separate strands, some 2,000 in number, two-hundredths of a millimeter in diameter, and each one insulated from the other. The power sent through the coils amounted to over a hundred horsepower, so that to keep them from burning up they were immersed in tanks of circulating oil. The generator itself was water cooled. Loading Coil in Series with the Secondary EN a low resistance detector is used, it is a good plan to tune the secondary circuit by using a comparatively small inductance coil and a large condenser, for then the current flow is at maximum and the voltage is quite low. For high resist- ance detectors the reverse is true. In- creased efficiency with such detectors as the audion can frequently be secured by inserting a loading coil in series with the secondary, and correspondingly reducing the capacity of the tuning condenser. This applies the highest possible voltage to the grid. 453 Double Set of Receivers to Amuse Visitors oe amateur who is continually having visitors will find two sets of binding posts for the telephones very handy. These can be best placed one pair at each TWO POINT SWITCH TO RECEIVER Two pairs of binding posts on each side of the receiving set for an extra telephone side of the receiving set. A two-point wood base switch, connected as shown in the illustration, will short-circuit either pair of telephones or leave both in cir- cuit—Harry N. BiIss. A High Voltage Lead-In Insulator Tube HE leading-in insulator described is cheap and effective, and will withstand the voltage of an ordinary 2 kw. trans- mitter. It is made from a hard rubber or composition telephone-receiver shell and two water-gage tubes. A 2 by 4-in. brass bolt is run through the cord-hole in the receiver-shell, after having soldered to its head some twenty strands of No. 20 or 22 copper wire, long enough to reach through the gage-glasses. The tubes are placed one over the other and V4" brass bolt SS =zzN Should cleare'toe’, ae nt sa | Two water glass gages carrying a high voltage lead-in wire run through a wall the wires run through; then the glasses are cast into the receiver-shell with sealing wax. A hole is drilled through the wall and the tubes slipped through and fastened with friction-tape. The water glass tubes are long enough to receive the rubber part of a telephone receiver on the inside for ap- pearance.—D. R. SIMMONS. 454 Making Your Window Tappers Tap Intermittently S a contrivance for attracting atten- tion to window displays, the electric window tapper has lost some of its former value, simply because Popular Science Monthly sing the attention of the passing crowds. In the drawing below the two contact wires B are shown mounted on the corner. screws of the clock frame. To do this it is first necessary to envelop the heads of the screws and a small part of their length with short bits of rubber tub- people have become so mene Set ee wer ing. The contact wires used to its buzzing sound =| Quy om reer comacr’B are twisted tight to this on the glass that they will — / sos rubber tubing, the latter not stop to look. The de- vice can be restored to its former usefulness, how- ever, by a very simple ex- pedient. Secure an or- dinary clock and around a spoke on one of its gear- wheels twist a piece of wire in such a way that GROUNDED 10, ates ee N THIS END OF rath CLOCK FRAME |). & LEAD FROM Hite paw thus insulating them from the screws. If the con- tact wires were not insu- lated in this way they would make direct con- nection through the clock 7) frame to the wire at- 4 tached to its bottom post and thus keep the tappers the loose ends project out- ward from the face of the wheel and form a pin A. This pin can be made to engage two or more contact wires at every revolution of the wheel. Thus an automatic circuit breaker is formed. This circuit-breaker, when introduced into the wiring of the window tapper in the manner shown in the illustration, will cause the tapper to buzz at intermittent, and to an observer going past the window, unexpected intervals. Two or more tappers, as the illustration shows, can be attached to the same circuit breaker, simply by mounting the corre- sponding number of contact wires in such position that the pin on the gearwheel can touch them in its revolving. The tappers, when placed in unexpected parts of the window, rarely fail to make a marked im- pression on a passer-by. As can be ob- served by studying the wiring, the pin on the gearwheel in revolving connects with first one of the contact wires, then the other. This causes the two tappers to buzz alternately, and for a short time only, in- stead of steadily, as is ordinarily the case. To a passer-by, the resulting sounds are as if a Hallowe’en ‘“‘tick-tack”” had suddenly gone off, and he stops to see what caused the commotion. By that time, however, the sound has ceased. But just as he is about to move on, the other tapper comes into action in some other quarter of the window with its own ‘“‘tick-tack’’—this due to the fact that the pin on the clock wheel has in the interval proceeded far enough to engage the other contact wire. Again the passer-by halts. In such manner the contrivance works all day long, focus- Wiring diagram to an old clock for making an intermittent current buzzing steadily—which is not desired. The only precaution necessary in erecting this apparatus is to see that the contact wires are insulated from the frame of the clock.—Lioyp E. Dar.ine. A Vibrating Ticker Interrupter Made Out of a Buzzer BUZZER, modified as shown in the illustration, may be used as a ‘‘ticker”’ - or “‘chopper’”’ for receiving undamped wire- less waves, or as an independent interrupter TO BE CONNECTED IN SERIES WITH PRIMARY OF COIL OR IN SECONDARY CIRCUIT OF RECEIVING SET *y ; ie CONTACTS wan \ LOOM \ If LONG CLOCK SPRING © “a wt Two vibrators or buzzers may be combined to give a multiplied vibration frequency SUB BASE for small spark-coils. The instrument can be constructed from one or two ordinary buzzers (depending on the frequency re- quired). When it is to be used as an inter- rupter it should be fitted with large contacts and a suitable condenser.—WERNER STAAF. Dust Proofing the Priming Cup on Automobile Engines S motorists well know, the presence of small particles of grit and dust in the cylinders of an automobile motor causes much trouble. Unfortunately most prim- ing cups are the source of this trouble. Theycollect dust which is washed into the cylinder when priming the motor. Here- with is shown a cup designed to prevent such trouble. It consists of a brass body A threaded on the end so that it can be screwed into the cylin- der. Just below the small tapped hole in the body is a conical seat for the needle- valve C, which is made of steel. The upper end of the needle-valve is riveted into the cap B, which is knurled on the outside so as to present a good gripping surface. The needle-valve is seated by screwing down on the knurled cap.—W. Burr BENNETT. CCA Hi qui W142 My Cn ee ih BROT TITTY Trent ty me \ WEE a Cap for the cup with needle-valve Proper Care of Inner Tubes to Prevent Chafing F tire users better understood the con- struction of inner tubes, and factors which contribute to their wearing out, it would be easy to secure more and better service. Spare tubes should not be carried in the cardboard boxes furnished from the dealers’ shelves. There is much danger of their being chafed. Tube bags can be secured for this purpose. If the car is equipped with smaller tires on the front wheels than on the rear wheels, an extra tube should be secured for each size. The cross-sections of inner tubes are made a little smaller than the normal air space inside of the cases. It is not advis- able to use a 4%-in. tube in a 4-in. case. This usually wrinkles and creases the rub- ber, with bad results. Do not use a 4-in. tube in a 4)%-in. case for any length of time. When this is done the rubber is stretched too much and the effect of heat and displacement of air in the tire quickly uses up the life of the tube. If put into usage for which it was not designed, the tube will not, as a usual thing, render efficient service. If it were practical to use one size of tube in another size of case, tire manufacturers could effect a big saving in equipment and furnish only a few sizes of tubes. Lubrication is most important to con- ' servation of the tube, but it is a matter that is given the least attention. Practically all tire manufacturers treat the inside of cases with a white solution to prevent tubes from sticking to the adhesive ‘‘fric- tion’ of the fabric. A good lubricant, however, should also be used. Some tire users neglect dusting soap- stone inside of the case when changing a tube. Others use the soapstone so sparingly that it does but little, if any good, or they may use so much that it does more harm than good. If a quantity of it be dumped into the case it will collect at one point, and during the hot weather will heat up to such extent as to burn the rubber of the tube, making it thin, brittle and lifeless. This results in a honeycombed appearance. Soapstone is the lubricant most used for tires and is satisfactory, but not lasting. Therefore, a fresh supply should be put in the tires at least two or three times during the season. Powdered mica has proven a more durable lubricant than soapstone, and quite as effective as graphite, and is much more pleasant to handle. It should be dusted on the fabric all around the case and on the inner tube to cover every par- ticle of the surface. 455 456 Bath Water Supply System for an Army Camp HEN the cold days of early winter set in the army boys on the Border began devising ways and means of heating water for the bath. In many camps differ- ent devices were to be seen, but - the one that ap- pealed to me most was a bar- ~=*\ rel used as a tank, with a coil of pipe connected ‘with it for a water heater. The barrel was placed on a table to make its lower See - end considerably Fe above the fur- ° ~~ OUTLET VALVE" & nace top. A pipe was led from the bottom of the barrel down to a tee joint, then horizon- tally to the end of the furnace, where another tee was used to make connections for the coil in the furnace fireplace. The opposite end of the pipe-coil was connected with the pipe system from the top end of a range boiler set on another small table to bring its lower end above the fireplace coil. The barrel supplied the water to the tank as it was drawn out through the faucet. The furnace in this case was the incinerator, which was kept burning at all times. Con- sequently there was hot water ready for shaving and washing, as long as the barrel was kept filled. This is a simple way of solving a hard problem and can be readily adapted for use in small camps.—GEORGE M. PETERSEN. The Right Meaning of the Term Reaming VERY machinist knows what it is to be asked to “‘ream’’ out a hole a little larger,—“‘little” varying from a few thousandths of an inch to % in. Asa matter of fact the lay public knows very little about reaming. The truth is this: Holes for reaming are drilled from .003 to 1/64 in. smaller than the final size. Thena reamer is used to bring the hole up to the exact size, round and true, which cannot be obtained with a drill alone. More than this amount cannot be taken out with any FROM eoitt0 BOILER ~ She. TO COIL FROM BARREL * A range boiler and a barrel with pipe connections for heating water from an incinerator fire to supply hot water for baths Popular Science Monthly ordinary reamer for metal. Not only is this true, but the construction of a reamer prohibits it from even starting in a hole any smaller, as the end is only 1/64 in. smaller than the final size. Reamers do not cut oversize. Thus, if a hole is reamed to 34 in. and a shaft is a tight in it, the opening cannot be enlarged a tri- fle, or. out a little so that the shaft is loose.”’ Stock reamersaremade in sizes varying “ by sixteenths. Any size between must be made to order. Expansion reamers are not made in sizes un- der 34 in. The reason for this construction is to allow the teeth to be sharpened and “‘set out” again to the original size. They are seldom found in small shops and do not enter into the case in the every day re- quest to “ream it out a little.” Remember a hole can be enlarged not more than 1/64 in. by a reamer and not even that much unless the hole happens to be that 1/64-in. under a standard size in sixteenths. A Handy Method of Sending Small Coin by Mail- SAFE and handy method of inclosing small coins in letters, if you do not happen to have the regular coin holder at hand, is to use a piece of corrugated cardboard, such as may be found in discarded wrappings, egg-boxes, etc. Simply cut a slit in one side of thecorrugated board, push the coin in and press it down flat. Be sure to -write on the outside of the cardboard, “Coin in here”’ or “Money in- side the card,’ so that the re- ceiver can readily find the coin between the sides —ALBERT B. WEGENER. Corrugated board Slitting a corrugated board to hold coin feeling, quite as much as economic reasons, impels the automobile owner to paint or refinish his own car. The time- saving, ready-mixed preparations—full di- rections on each package—now in the market, will aid him greatly. By purchas- ing advertised materials, put up by reliable manufacturers, he can, if he follows the directions carefully, look forward to a satisfactory termination of the work. A few coats of material carefully put on and allowed to dry out thoroughly will look better and give better wear than a dozen coatings carelessly applied. If the car is in such bad shape that all the old coatings must be removed down to the wood or metal, procure a can of paint remover, and use as directed. After all the old coatings are removed, wash the car with gasoline to remove all traces of the paint remover, then smooth the surface with No. o sandpaper, and clean out all rust spots, cracks and depressions with emery or sandpaper. Dust off and apply the priming-coat and proceed as in re- finishing. Presuming that the car is to be finished in black, which is the safest, and at the present time the most popular, purchase the following materials: ote enjoyment of that ‘‘did it myself” 1—1 lb. can of coach black-ground in Japan 1—1 lb. can of white lead I can of (black) color and varnish, mixed 1 tube of oil color for lettering and striping I quart of turpentine ¥ pint linseed oil ¥% pint Japan drier I quart rubbing varnish I quart finishing varnish ¥ lb. ground pumice stone I putty knife 1 felt rubbing pad, made from old felt hat I can patent crack filler VY Ib. whiting 4% doz. sheets No. 0 sandpaper for rough work doz. sheets No. 00 sandpaper for fine work 1—2¥-in. flat brush for color Painting the -Automobile = By James M. Kane 1—% or 4-in. flat brush for color 1—2%-in. flat, chisel shape, varnish brush 1—%* or \-in., chisel shape, varnish brush I or 2 camel’s hair stripers—fine I camel’s hair, or sable lettering brush, small The large brushes are for the board surfaces, and the small brushes for the edges, moldings, etc. The whiting and Japan drier will be necessary to make hard putty, but unless the depressions are deep, use the patent crack-filler exclusively. Add enough black color to the putty so that it will match the gray color of the priming coat. Putty is made of whiting, raw linseed oil and Japan. A good putty can be made of dry white lead mixed in equal quantities of coach Japan and rubbing varnish, which is reduced with turpentine if necessary. Whiting is designated in the list of materials, but if the last mentioned recipe is used a small quantity of dry white lead can be used instead of whiting. Tell your dealer what you want the materials for. He may be able to give you some valuable information regarding new preparations. Painting Room Select a clean, well lighted place in which to paint the car. A room that can be heated, if necessary, is best. Jack the car up on 4 strong boxes or trestles. Arrange them far enough away from the wheels to give you room to work on the inner sides of wheels. Do not remove the wheels as the bearings may drop out, and.they are hard to replace. Wash off all the mud you can with a hose. Scrape off all greasy mud and grease, with a scraper or putty knife. Take a stiff brush, dip it in gasoline, and loosen up what remains in the crevices and on the surface. Clean out the brush and give a final scrubbing with clean gasoline to re- move all traces of grease and greasy mud. 457 458 A sponge saturated with clean gasoline will be handy in the work. For your priming coat, mix the white lead with turpentine, adding a little oil and Japan drier. Add enough of the coach black to color it a dark gray. Apply this evenly to the surface, dusting it off first, just before painting. When this coat is thoroughly dry, fill up the cracks and depressions with the crack filler, or putty, allowing the filler to project a trifle above the surface, as this permits the filling to be cut down level with the painted surface. Now smooth the surface all over carefully with No. 00 sandpaper. Some painters use the crack-filler mentioned as another coat painted all over the surface. Then it is smoothed with sandpaper. This is easily accomplished because of its hard drying qualities. Black Color Coat Mix up some of the flat-black with turpen- tine, adding a little oil to act asa binder. Do not add any Japan drier. Apply a smooth, 7. even coat of <= Popular Science Monthly HORIZONTAL STROKE ew During the progress of the work you may notice that the surface is slightly unlevel here and there, but as coat after coat is applied and rubbed down, these places will gradually come up to the level, and when the finishing varnish is applied the surface will be smooth and glistening; that is, if the work has been done carefully and plenty of time given each coat to dry before resuming the work on it. Sandpapering - eas Sandpapering must not be attempted if the surface is not thoroughly dry. The loosened material should fly off like dust during the operation. If it clings to the sandpaper in spots and cakes, the surface has not dried out. Give it a day or more to dry out before going at it again. The same advice holds good for the rubbing down with the pumice. No dust will fly, as the pad must be kept wet, but the surface should be just as hard as for sand-. papering. Dur- START this, and let it dry. After this, lay on a coat of black color and rubbing varnish mixed. Use the ready mixed article, rather than your own mixture of black coach color, rubbing varnish and a little turpentine. When the color and varnish coat is dry, rub it down even with pumice stone and felt pad. Do not use sand- paper, as the succeeding rubbings are to be done with the pumice stone. Wet the felt pad, dip it in the for pumice and shake off the surplus powder; then go over the work with an even circular motion on the large spaces. Rub in straight lines along the edges of the doors, panels and on the mold- ing. When the surface is cut down evenly, wash off the pumice, dry, and apply a coat of clear rubbing varnish. Let this dry and then rub down with pumice stone as before. Wash the surface thoroughly and when dry, put on the striping and letters. A carmine, or dark red stripe looks well on a black sur- face. The object of all this rubbing down is to secure a perfectly even surface before applying coat of finishing varnish. Methods of holding brush striping as at ing the pumic- ing, wash off the surface with a wet sponge to remove the abraded ma- terial, as well as to see how the work is proceeding. Striping adds a distinctive ap- pearance to any car, but its applica- tion requires the skill, the accurate eye and steady hand of the expert. - Poor striping is an irritant to the eye. The proper and only stripe on a pleasure car is a thin, hair-line 4 or % in. away from the edges or moldings of doors and panets. This stripe should follow the lines of the doors and panels. Some- times-the curves of the mudguards, and those of the hood are also striped in the same way. All automobile wheels are not striped alike. Examine the striping on various wheels and follow the style that pleases you best. Actually, the stripe is a contour line—sectional or continuous. To stripe, take a clean, flat piece of glass or tin, place a small quantity of the tube ~ color upon it and thin to working consis- tency with a little turpentine. Then take the striper and draw it through the color to load it. Draw it toward you several times on the clean surface of the glass or tin, A j , so as to wipe off the excess color. In doing this you will notice just when there is enough color in the brush to make a stripe of even density. If the brush is too full, the stripe will thicken and spread at the edges. Take the brush between the thumb and forefinger, with the thumb uppermost. Now place the point of the brush on the exact spot where your stripe starts, and with the fingers resting lightly against some convenient parallel surface, draw the hand backward with a quick easy move- ment, to produce the stripe. The fingers act as a gage and a movable rest. .Don’t make the stripe in short, jerky sections, or it will look patchy. Make it in one, quick, uniform stroke. If there were no curves to be turned, the amateur striper might do a passable job with a fine sable, or camel’s hair brush and a straight edge, having a padded projection at each end of the straight edge to raise it off the surface of the car. But since the curves on an auto are numerous the striping had best be omitted, since faulty work will surely take all the shine off an otherwise well finished piece of painting. Lettering Put on the initial letters about 14 in. high, with the same tube color you have used in striping; or you can vary the color if you wish the letters to contrast more or less. The small-sized letters, like the )4-in. size, seem to be much preferred to those of greater height. Outlines of letters, or monograms may be transferred to the surface as follows: After having drawn or traced the letters, or monogram, on a clean sheet of paper, in the precise shape you wish them to appear on the door or panel, rub the reverse side of the sheet with a piece of chalk, dusting off the excess chalk. Place the paper on the REST FOR TYPE OF PURVE~ ESS LETTER Popular Science Monthly . 459 proper spot and holding it firmly, go over the lines of the letters, or monogram with a pencil point, or a pointed piece of wood. Upon removing the paper, the letters will be seen in white chalk lines wherever your pencil point has pressed upon the paper. Before transferring the letters, cut the paper to a convenient size so that it can be handled easily. Also draw two lines at right angles upon it for the purpose of centering on a chalk dot you have placed on the door, or panel. Be sure you have gone carefully over all the lines of the letters before removing the paper. By holding the paper firmly in position, you can turn up the edges and see whether you have missed a line or a letter. Do not bother about cleaning off any chalk-marks until the letters are dry. These marks can be easily sponged off before varnishing. If you cannot turn neat curves in letter- ing, do not attempt letters of the curved type. Rule the letters up as though you were forming them with a pen and ruler. If you happen to draw an incorrect line either in striping or lettering, wipe it out quickly with a lump of absorbent cotton slightly damped with turpentine. Dry with a clean piece of cotton, and be more painstaking in replacing the line or letter correctly. If the line be difficult to erase because of its being close to other lines, do not use the lump of cotton, for fear of blurring or smudging the correct lines. Take a piece of soft pine the length and thickness of a lead pencil. Whittle both its ends into pencil-like points, nicking them on their sides so as to raise a little of the wood. These nicks will prevent the cotton from slipping off. Wrap a clean piece of cotton around each end, forming each piece into a blunt, pencil-like point. Use one end of this eraser, dampened with turpentine for removing faulty lines or spots. Use the LETTERING CENTRE LINES ON TRANSRER PAPER ie ce a: Nad A straight edge with padded ends is used curveless letter for initials and erasers are made of nicked sticks and cotton covered ends for guiding the striping brush. Forms of a 460 other end dry for finishing the erasure. Use -a clean piece of cotton each time you have occasion to remove any paint. Varnish is not applied merely for the purpose of securing a highly polished surface, but also as a protection to the underlying coats of color. Have your paint shop clean before you start varnishing. Allow no open doors, or cracks to conduct a dust laden current of air against the ves sol Popular Science Monthly that has run or shows a tendency to gather. thickly at the edges of the panels, etc. Never miss any spot, however small. If you do, you will just naturally try to patch it, (after the rest of the surface has set) and botch the whole job. ; In varnishing the wheels, be careful to keep the varnish from running down the spokes and settling thickly between them where they enter the hub. After varnishing the rim, spin the freshly varnished surface. Let the heat of the shop and that of the varnish be the same, say about 70 degrees. Never have it cold. After having dusted off the car take the large var- nish brush (2% in.) and put the varnish on, but not too thick. Do not fill your brush so heavily that the var- nish will run down the handle while you are working. Just put enough paint on wheel easily, holding: the brush lightly against it to smooth out and join the laps: on the rim. Finish the hub in the same manner. j When the job looks right, surfaces evenly covered, no thick places at the edges, and all places. coated, put your brush away and leave the car alone. Stand the hood cover on its edge so that the dropping dust will not fall on it. Lay a board sup- ported on two tres- tles over the mud-. a wa y Rs the brush to go over the space easily, and never work all the varnish out of the brush before taking up a fresh brushful. Do not tickle the surface with short strokes; but brush easily from one side to the other, and then up and down. This is called cross-brushing, and gives uniform depth to the coat, which is just what you want to secure. For all surfaces that can- not be conveniently coated with the big brush, use the 34-in. brush. Varnish the moldings or raised portions around the panels the same way in which they run; that is, follow their lines along or around the surfaces they enclose. You can run across them with the big brush, but always finish with the small brush in the way described. Always finish one section first, if possible. Take a door or a panel and complete it before going on to the next one. Pick out the small areas first and by the time you tackle a big stretch you will have more . confidence to handle it. As you go along, take up any varnish Putting on the initials of the owner’s name in the center of the front automobile door guards for the same purpose, or use an adjustable shield. Allow plenty of time for the last coat of varnish to dry. Let it stand for two or three days at least. When thoroughly dry, wash it with clean, cold water, dry with a soft chamois and the car is ready for use. You may possibly have some trouble in mixing your priming coat. Better mix it a day or two before you begin work. This will give you a chance to try it on the sur- face, for drying and hardening qualities. Don’t get it thick. It may need a little more Japan to harden it or turpentine to thin it out, but it will not require any additional oil. Keep it in a tightly topped can, and it will be all right when needed. Good coach putty should dry hard, and stand sandpapering without scaling or softening. One authority suggests a putty composed of 3 parts whiting and raw lin- seed oil mixed with 1 part white lead. A little Japan should be added to harden it. This putty must be stiff and well worked up. Another prescription calls for a mix- . J ture of dry white-lead mixed with varnish, _ Japan being added as a hardener. The safest plan is to buy all the materials ready mixed—if possible. Clean the paint brushes in gasoline and the varnish brushes in clean turpentine. Wash out with warm water and soap, and they will be in good shape no matter how _ long they are laid away. Fastening Nails So They May Be Quickly Withdrawn EN nailing a box, such as a form for cement where it is necessary that the contents should not be marred or injured, put under each nail-head a small piece of lath or other bit of wood. When removing the nails split away the small piece of wood and enough of the nail head will be exposed for easy drawing.—LINDALL WILLIAMS. An Emergency Wire Stretcher for Repairing a Fence FTER turning the cows into a field I happened to find a broken place in the fence and I did not have the time to for a stretcher at the other end of the tha Finding a hickory stick in the wood pile I sawed off a piece about 3 ft. long for the handle. I could not take the time to prepare a fire for heating an iron so I flattened the end of a 14-in. bolt and drove it in one end of the stick, then beat the head to make it rough like teeth. Several inches from the end I fastened a short length of chain and a hook taken The hook was bent from a singletree. The bolt end of the homemade lever is placed on the post for stretching a fence wire so that the barbs on the wire could not slip through. en barbed wire becomes slack it can be tightened by catching it between the claws of a hammer and making a series of kinks. These kinks should not be too short to weaken the wire.—J. L. PINKSTON. Popular Science Monthly 461 A Bubbling Drinking Fountain with Icing Reservoir HE bubbling fountain shown in the illustration was made by a workman in a large institution at a cost of $8. 75 for the material, to replace an expensive one that had become use- less. The body is made square of heavy gal- vanized iron. There are two boxes of the size shown, the space be- tween them being filled with pow- dered asbes- tos. An or- dinary bub- bling cup A with its valve is con- nected with the upper part of the water reservoir B. The pipes, C and D, are the ordinary in. galvanized kind. The supply comes through the pipe D where it enters a 2-in. galvanized pipe B used for the reservoir. A key tap is placed in the line D for regulating the flow. A waste pipe F is attached, as shown, to keep the cup C free from water. The cover G can be lifted and enough ice put in to last from 5 to 7 days, according to the quantity of water used. A small drip between the boxes is shown at H, while the waste to the sewer isshownat J. The tank is elevated on four blocks for air to pass below it.— James E. NOBLE. A Hat Hook or Holder Made of a Lead Pencil F you can’t find ahook to hang your hat on and wish to furnish some amusement quickly take an ordinary pencil, find a smooth board surface, and place the pencil flatly against the surface, holding it length- wise. Briskly rub it up and down for a few times and it will immediately adhere without any danger of falling off. A hat can be hung on it providing the headgear is not too heavy. The “impromptu hook” will remain in this position until removed. —CLARENCE T. HUBBARD. Ice-water tank with bub- bling fountain attached 462 A Tie for a Shoe Lace That Will Stay Tied T is not always the large things that annoy us most as a persistent vexation. By this is meant that when some important thing annoys us, we immediately set about correcting the trouble, but a small thing— too trifling to - bother with— will worry us repeatedly and we give it no at- tention. A very good example of this petty an- noyance is shoe laces. Many times a day do we see people stop by the way- side and tie their shoe laces. Es- pecially is this true with new Two turns in shoe lace tie will hold it tightly laces. One extra turn of the lace about the first loop made will produce a secure fastening even if not drawn absolutely tight. The ordinary bow-knot used to fasten shoe laces is shown in Fig. 1. The string A is given one turn about the string B at C, before the loop of string A is passed through. By making two wraps as shown in Fig. 2, at D, before passing the loop in string A through, a fastening is made that will not slip or shake loose. It is so simple that it is strange that you have never found it out before, but it does the trick and holds tightly —Gro. S. Brown. Keeping the Strands of a Rope End from Unraveling HE three strands of the rope are separated as shown at 4, then the strand marked I is turned over between 2 and 3, then 2 is turned over on 1 and between the base of 1 and 3, as in B. The end of the strand 3. is then run through the loop of I as in C and drawn up tightly asin D. The strands are then cut off close to the knot.—Tupor JENKS. ends are tied into a knot Popular Science Monthly Saving Chemicals by Machine Development of Film HE amateur who undertakes to de- velop his own moving picture films finds many difficulties, which, to say the least, are discouraging. The films are long and unwieldy unless wound on drums or racks, nor can they be handled after being wet. If the drum system is used the space required for operation is prohibitively large for most amateurs. If the tank process is used there must be at least three tanks, one each for the developing, fixing and washing BELT PULLEY, “iy rNTh) = 1@ = lead FH SLOTS TO RECEIVEL BH BOLTS OF FILM BRACKETS rT] po cone fan ween 4 ABOUT 6’ . £2 DRIVE PULLEY COMPENSATING SORING = ‘iy, tees be The upright and its attachments for driving moving picture film through the chemicals solutions; and the space necessary for their installations, as well as the cost of the tanks themselves, puts it beyond the reach of the amateur at home. In addition to the space required for the tank system, about 35 gal. of developer will be necessary to fill a tank that will handle 200 ft. of film. At the present price of chemicals this would cost about $20, and as it deteriorates rapidly whether it is used or not the development is rather expensive for a single film. The experimental engineer for a moving picture concern in the west was forced by the limited size of his laboratory to install a developing, fixing, washing and drying apparatus for moving picture films, which ee Te es Fe fo RI re a is simple, efficient, inexpensive and small. _ A small commercial house could, in some _ cases, use the plan to advantage. The - outfit can be placed on the wall of the dark _ froom in an unused corner. Made in | ISS ie TS OE Pe, Seagal This method of development economizes in chemicals, as a very small quantity is required approximately the dimensions shown, which may be varied to suit the conditions, it will accommodate from 10 to 100 ft. of film and it will use less than 1 quart of developer per 100 ft. of film. The film to be developed is wound around the rollers as if it were a belt, with the emulsion side out. The upper bracket carrying one of the multiple rollers is adjustable for different lengths of film, so that the single idler will serve to compensate for the slight variation in the film length during developing and drying. When ad- justed properly the ends of the film are spliced together, thus making a continuous belt. The upper set of rollers consists of a flanged stick on a shaft equipped with a grooved pulley so arranged that it can be belted to a motor or, in the absence of a motor, to another wheel placed con- veniently and fixed in a way to enable the operator to run the apparatus by hand. The developing pan or tray is preferably an enameled baking pan which can be partially filled with either developer, water or hypo solution and raised underneath the bottom set of rollers so as to immerse the running film into the several liquids as desired. The film can be stopped and examined at any time and the solutions changed in a few moments, especially if the Popular Science Monthly 463 operator has a pan for each solution. After development, fixing and washing, the film may be quickly dried by running it over the rollers while the air from a fan is turned on it, provided the room is free from dust, which is essential for all the work. In setting the apparatus for any length of film it can be marked on a scale for future use, or by the_use of a tape line the device can be calibrated and marked so the rollers may be set at once and properly for any length of film. The entire apparatus should be painted with paraffin dissolved in gasoline to prevent the wood from wetting and swelling, and to prevent the absorption of fluids by the unprotected parts of the frame.—T. B. LAMBERT. A Driver to Turn Studs in Aluminum Castings ETAL workers who attempt to put studs into aluminum castings usually do the job with tools not intended for the work. A very handy tool may be made for this work, as shown in the illustration. It will be necessary to have a set of these tools, one for each size stud used. The stud is screwed into the tool as far as it is necessary; then the center piece is screwed down tight upon it to hold the stud in place. The stud may be driven tight intothe casting and the center piece loosened; then the tool may be turned off from the stud with perfect ease, leaving the stud set. The shank of the tool is made of hexagon stock and the center piece of 34-in. round ma- chine steel— THERON L. WINCHIP. A driver to turn studs in aluminum A Lasting Paint for Covering a Heated Surface GOOD black, heat-resisting paint for the front of a locomotive, or other place subject to heat, can be made in the following manner: Shave 6 pounds of brown soap and melt it in water, then add more water to make it up to 12 gal. Mixin 18 gal. of Japan oil, then stir in 80 lb. of the best graphite. This will make about 35 gal. of paint. Stir the mass well and apply while the object is not too hot. 464 Keeping Vise Jaws Open with a Coil Spring VERY mechanic knows what it is to. work with an old vise where the screw and nut are so badly worn that it becomes necessary to back the movable jaw farther than necessary when inserting the work. The trouble caused by this back lash can be eliminated by thespringshown in the illustra- £1.0.n..:.i Tae spring A is-in- serted between the two jaws and kept in place by two plugs B, which are driven into holes drilled in the jaws. It is evident that, as the handle is turned back- ward, the movable jaw will follow because of the spring pressure, thus eliminating all loss of motion. There is only one objection to this; that is, it fills up the space between the jaws. When necessary the spring may be easily removed.—W. Burr BENNETT. Spring in vise jaws to hold them apart Making Large Fly Traps for Packing Houses ETTING rid of flies in packing houses is one of the problems which has engaged the attention of the Bureau of Entomology in cooperation with the Bureau of Animal Industry of the Department of Agriculture. An extensive investigation of the various types of fly traps used at the establishments where Federal meat inspection is main- tained has been made. While there has been much varia- tion in the effective- ness of different types of traps, it has been found that the conical trap is most efficient: One type of mechanical trap has been found par- ticularly effective. This trap is 24 in. high, 18 in. in diameter with a cone 22 in. high, by 18 in. in diameter at the base. The frame is constructed of four hoops. Two of these hoops 18 in. in diameter are A cone within a cylin- der, both of screen wire Popular Science Monthly nailed together. They form the bottom’ of the frame and the other two the top. The top of the trap may be made of an. ordinary barrel end, with the bevel edge. trimmed off so that the head will fit closely in the hoops. A 10-in. square is cut out of the center of the top to form a door, the portions of the top being held together by I-in. strips placed around the opening Y in. from the edge, to form a jamb for the door. The door is a narrow frame covered with a screen well fitted to the trap. The top is then nailed to the upper hoops. The outer part of the trap is formed by fastening fine mesh galvanized screen wire to the outside of the hoops. Four light strips are tacked to the hoops on the outside of the trap to act as supports between top and bottom hoops, and the rT | . ft). rg < : 4 : 7 4 ; “8 ; 7 7 7 : a ~ 2 67@ 4 E ’ 8 Laying out a pattern, with an ordinary car- penter’s square, for cutting the cone wire mesh > y-7 I eEbES Pr PETES PTT) ends are allowed to project at the bottom to form legs. The cone is cut from the screen wire and may be either sewed with wire or soldered where the edges meet. The top of the cone is cut off to give an opening I in. in diameter. The cone is then inserted in the trap and tacked to the hoop around the base. The fly trap is now complete. In constructing the cone it is best to cut a pattern from a piece of heavy paper. An ordinary square is placed on the ma- - terial from which the pattern is cut. A distance equal to the height of the cone is laid off on one leg of the square and a distance equal to one-half the diameter of the base of the cone is laid on the other leg. A line is then drawn between the two points A—B. In order to figure the distance around the base of a cone of any given diameter, multiply the diameter by 3.1416, or 3 1/7. Cut out the pattern on the curved line from C to D and on the dotted lines from A to C and A to D. Popular Science Monthly Some Short Cuts to Hasten Work in Sign Painting © Qe prime factor in getting out sign work is speed. The expert who is not speedy is not in it. His work may not be perfect, but this is not so much con- sidered if he can hustle it out. There is great competition in this art, or business, and I have known of one of the finest and oldest established shops going under be- Fig. 1. A scale sketch of letters to be made one foot or more in height from original cause it could not attain the quick gait. Nor could it come down to doing such work as present day requirements demand. All this being true, it is surprising that so many will take the longest and most laborious way of doing certain kinds of sign work, that can be done in a far better way. Some think that the expert sign painter has merely to take a survey of the job before him and form in his mind’s eye the whole lay-out, without bothering with calculations or measurements. It is doubt- ful if any sign painter now living could do this. It is perfectly proper to train the eye for this work, for that will enable the work- man often to do certain work without taking time to measure or lay it off ac- curately. A large portion of sign work is done in this way. But he should not rely too much upon the eye alone. For certain large sign work, the ‘“‘scale sketch” is the thing. It enables one to get all the letters right as to form and space; otherwise there would be some trouble at the end of a line, a\e Fig. 2. Dividing lines in which an enlarged layout can be made by measurement say, where letters would either have to be cramped or extended. Perhaps the most convenient scale is that of 1 in. to 1 ft., giving eight eighths of 1 in., thus representing 1 ft. or 12 in. In Fig. 1 is shown a 1I2-in. letter in this scale. With this scale you get the 465 proper widths of both vertical and _hori- zontal strokes, and this will be found a great advantage when the lettering is from 2 to 5 ft. in height. The scale sketch is particularly useful when the sign work is high above the ground, and must be done from a scaffold or ladder; still more especially where the lettering takes a line so long that the swing stage must be moved once or more. Or when done from a ladder which must be moved several times. You simply take the sketch up with you, and set out the letters. Of course, the surface that is to be lettered must be measured and laid off in spaces the size the letters are to be when finished. Then it is simply a matter of reproducing the letters from the scale sketch to the wall. And with two or more copies, two or more painters can work on the letters, each with a certain part of the work to do. Or the workman may begin at the end, or in the middle, anywhere, sure that the work will be perfect. This laying out of a sign at an altitude may be done where possible by counting the rows of bricks, four to the foot, or if there are no bricks, the width of the sign can be had by measuring along the base << Fig. 3. Large elliptical curves may' be drawn by angular lines, then drawn in freehand of the building, this for making the scale sketch. The width may be laid off on the wall with the rule. The illustration Fig. 2 is not drawn to a scale, but is intended to show, by its dividing lines, how a man working from a ladder could set out and paint in the letters as he goes along, always measuring from the last upright on the sketch. Get the dimensions as previously suggested, from the ground, etc. The upright lines serve as a guide and the lettering is fancy, not standard. This is a very easy. and quick method of lettering, and gives a good appearing sign, too. Large sweeps or elliptical curves are dif- ficult to form from ladder or stage. An easy way to form such sweeps, as they are called by the workmen, is shown in Fig. 3. The sketch explains itself very clearly. 466 First draw the angular lines, and then with chalk or charcoal draw the sweep freehand. . The angular or straight lines serve as a guide. Another illustration (Fig. 4) is of the Fig. 4. A pair of wood dividers are used to make sweep after drawing the angular lines same method, but in this latter case the wooden dividers, which are very large and made for the sign painter’s work, will usually be found sufficient for making the circular sweep, and if the sweep is to be elliptical, as it most always is, it may be made freehand, with the compass lines as a guide. The compass would do only for small signs. In Fig. 4 the upright lines serve a useful purpose in dividing the sketch. Illustration Fig. 5 shows the use of flourish or ornament, sometimes a valuable addition to certain forms of lettering, and these may also be indicated on the scale sketch, getting the form true and just as Sez Fig. 5. An ornament added to a sign where it is necessary is laid out from a scale sketch it is to be when placed, enlarged, on the sign. The value of a beveled bristle fitch, used in connection with a beveled straight edge, is not appreciated as it should be for very large lettering work.—A. ASHMUND KELLEY. An Easy Method of Preparing Demar Varnish O prepare demar varnish, place from 4 to 10 lb. of the gum in 1 gal. of turpen- tine, and allow it to dissolve. Agitating it in a churn is the best method. You may also use a mixture of turpentine and benzol, or carbon tetrachloride and benzine, for cutting the gum, but just the pure turpen- tine is commonly used. The amount of gum used per gallon determines the body or weight of the product. Popular Science Monthly Rubber Plugs in Handsaw Handle to Prevent Its Falling © ’ HEN placed against awall a handsaw has a tendency to slide sideways and fall, often injuring the teeth. This is because the handle horns which touch the wall are smooth and polished, thus offering no frictional resist- ance. If these horns are pro- vided with soft rubber tips many a fall will be prevented. To accomplish this, drill a small yy or 3/32-in. hole about 3 in. deep in the side of the tip of each horn. Partly fill each hole with rubber cement or mucilage and insert a plug of soft rubber cut from an eraser. Set aside to dry. Have each plug project slightly, as shown. These rubber projections come in contact with the wall when the saw is leaned against it. This prevents the saw from falling down or sliding sideways. The same result may be obtained by winding an elastic band tightly around each horn.—Roy B. SNow. — Rubber plug Rubber plugs in handle to pre- vent saw from sliding away from a wall Using Ball of Soap to Recover Screw in Spigot N the type of spigot where the washer is secured by a screw the constant turning on and off frequently causes the washer to twist, carrying the screw with it. As a result the’ screw finally falls into the bottom of the spigot, from . \\ whence it is extremely \ difficult to re- move it. The usual method is to turn on the water and flow it out, but this is rather uncertain as well as inconvenient at times. I found by fastening a ball of soap on the end of a stick I could remove the screw easily by pushing the device down so that the screw would become imbedded in it. Nuts may be re- covered the same way.— JAMES M. KANE. all of soap ui Soap on stick end picking up screw ee EE eae N interesting fact about the develop- ing of a pattern for an elbow is that one piece can be used for any piece of pipe shown in the drawing, and many more combinations are possible. The method used in developing this pattern is exactly the same as in the “Trench Periscope’ and two-piece elbow pattern in the June, 1917, issue, also for the “Scale Scoop” in the July, 1917, issue. It is the method known as the “parallel line,’ which simply means that the pat- tern is developed by means of lines parallel Sheet Metal Working Simply Explained IV.—Development of patterns for three-piece elbow with adaptations By Arthur F. Payne Assistant Professor Manual Arts Bradley Polytechnic Institute the pipe. Third, step off the base line C-D equal in length to sixteen of the spaces marked off on the bottom view and number the points as in the drawing. This will give the length of the piece of tin required to make the pipe. The reason for number- ing two points one is that when the piece of tin is rolled up these points come together at the seam, making only one point. Project lines upward from these points on the base line as shown by the dotted lines in the drawing. Fourth, from the points on the bottom view B project lines upward . 7 3 Bottom view 5 + The parallel line method is used for developing this pattern for an elbow, which is used throughout sheet metal working for laying out many patterns of a similar nature in round work for turns to each other. All cylindrical pipe prob- lems are developed by this method. If you will compare the problems in the issues mentioned you will see that this is a fact. The first step in developing such patterns is always to draw the front view A, of the elbow to exactly the dimensions you need. Second, draw the bottom view # and divide it into 16 equal points. Number these points starting No. 1 on the seam of until they intersect the joint line (see dotted lines in the drawing). Fifth from the point where line No. 9 of the bottom view intersects the joint line E-F project a line at right angles until it crosses line No. 9 coming up from the base line C-D, make a cross where these number nine lines cross, as in the drawing. Do the same for line 10 and 8, 11 and 7 and so on around the bottom view. Sixth, you will now have a 467 468 series of crosses outlining the pattern for A. Connect these crosses into a freehand curve. Make the 3/16-in. allowance on each edge for lock seam and you have the complete pattern for A. Now comes the interesting part of this problem. The curve G- H is the pattern for every joint shown on the drawing; this is so because every one of these joints are the same angle. To get the pattern for J take the distance F-J on the front view and set it off as F-J on the pattern. In the same way take the distance E-K on the front view and set it off as G-K and H-K on the pattern. Then lay out the curve G-H as K-K, and the pattern for J will be as shown in the drawing. For the pipe Z on the front view, with the seam on top, we would use the pattern G-H-N-M. For the pipe O in the upper drawing, that part of the pattern for J marked K-J- F-G would give us one-half of the pattern for pipe O. For the pipes marked P we can use the same pattern curve but the top curve K- K would have to be drawn so that the low part J of the top curve would be opposite the low part G of the bottom curve. Similar adaptations would be necessary for the other pipes. Making Soldiers in Black and White on the Typewriter Y the use of a little ingenuity a sten- ographer, or any person who can operate a typewriter, may hammer out a whole regiment of soldiers on the type- writer, using the letters and punctuation marks found on all the standard machines. The accompanying sketch shows how lifelike the type- writer drawing is. The ‘“‘&”’ sign supplies the head, chest, and arms, a small ‘“‘o’”’ the body, a period the cap, a capital ‘‘W”’ the legs, a double an quotation mark (“‘) the feet, emp = =82iand the hyphen standing Soldier space. A colon provides two shaped from f buttons for the coat, and the type prints transverse line used in making fractions makes a remarkably lifelike gun. Best results are secured by making a whole row atatime. If the typewriter is equipped with a double color ribbon, very pleasing effects can be produced by printing the char- acters in different colors; for instance, the cap and trousers red and the others black. Popular Science Monthly A Cigar Cutter Attachment for a Pocket-Knife O make a handy and novel cigar cutter procure a bone or wood handle pocket-knife and with a round file make an arc of a circle cut in the handle about 34 in. from the hilt as shown at A. To trim the cigar open the blade of the knife and place the end of the cigar in the arc, shut the blade quickly, and the deed is done. The notch does not harm the knife in any way.—C. T. WANDRES. The cigar pen sy is put in the notch for cutting Clothes-Hangers Used for Handles on Barrel Covers ARRELS used as containers for storing apples, potatoes, and the like are usually kept closed with a detachable cover. To handle such covers conveniently it is necessary to have some kind of a hand The small double hook screw hanger makes an excellent handle for a barrel cover grasp. A clothes-hanger will answer the purpose nicely. The kind illustrated has two hooks with a screw point in the center. It is quickly applied.—H. DRoBE. A Knock-Down Canvas KNOCK-DOWN canvas boat, 10 ft. in length, weighing complete less than 20 lb., capable of carrying 300 Ib. and which may be made easily by any young man, is illustrated in the accompany- ing drawings. The entire frame is made of either spruce or birch, the latter preferred, the material being in strips 34 in. thick and 1% in. wide. The widest pieces are the seats and keel boards, all of which are 5 in. with a thickness of 34 in. The illustration does not show the canvas, as the manner of constructing the frame is the important thing to be considered. When made according to directions it will be found very rigid, even before the canvas is applied. The bulging shape of the keel and the midship section of the canoe have a wonderful stabilizing action on the craft when it is in motion. Two pieces of keel strips A are provided, each 6 ft. long from the center of one hole to the center of the other. To each end of the two parallel keel strips thus described is attached a keel extension strip B, each of which is 26 in. from hole to hole. Each hole in these strips is to be bored with a 3%-in. bit, and bolts 214 in. long should be used. Suitable washers should be used behind each bolt-head or nut and properly sunk into the surface of the wood so the head and nut will fit evenly. Eleven keel boards, each 6% in. long, are ranged along the two parallel keel strips, the keel strips being spread apart in the middle so they measure 6 in. from outside to out- side. The keel boards C are then laid on evenly and nailed to the keel strips, thereby providing a suitable runway for the occupants of the canoe. ‘ —~ —— ——— wom = a, he The side, or gunwale strips D, are 6 ft. long, each end being cut off square on a vertical line, but on an angled line in a horizontal direction. To each end is fitted a side extension bar E, by means of a hinge, the opposite end having a hole 24144 in. from the angled end. These extension bars are joined at their ends to the end of the keel extension. The three lapped ends are secured by a bolt. It is now necessary to join the keel portion with the gunwale frame. A span frame for each end of the canoe, and a pair of span frames provided with seats are placed midway between the end spans. The frame for the ends is made of a top cross-piece G, of material 34 in. thick and 2 in. wide, which indicates the dimensions of all the parts of the span frames. Each cross- piece of the two end frames is 22 in. long, each end having a cut-out portion 114 by 34 in. in which the side pieces D rest. A hole through the side piece and end of each cross-piece permits a pin to be driven in to hold the parts together until the canvas is applied. The fabric will prevent the pin from coming out. Two V-shaped pieces extend down from the ends of the cross-piece, the lower ends being held together by a short cross-piece. The ends of the V-pieces are cut so they span the keel strips, while the short cross- piece rests on the keel strips and thus serves as a support for the upper frame- work. The seats F are each 30) in. long, and at each end is a cross-strip or cleat, 469 470 34 by 34 in. in size, nailed thereto. The two lower depending strips, arranged in V-shape, are secured together at their lower ends by a cross-strip which rests on the keel strips, in the manner described in SJ 10 CROSS FRAME reference to the end frames. Pins or screws may be used to hold the seat frames to the body of the canoe, but small bolts are preferable for this purpose. The entire framework, together with the canvas and oars, can be knocked down and folded in a space 6 ft. long, 1 ft. wide and 6 in. thick, and can easily be shouldered and carried by a boy. The end extension pieces B, swing down and rest between the keel strips A. The hinges on the side bars D, provide a means for swinging the end pieces alongside the bars for packing purposes. The Cause and Prevention of Rim Cuts on Tires ROTECTION from rim cutting is not afforded by any particular type of tire but depends rather upon the design, quality and usage. No good tire of standard type will be cut by any standard rim, if properly used. On the other hand, any type of tire will be injured if subjected to abuse. Under-inflation, dented and irregular rims, excessive loads, tire fillers and stiff reliners are the common causes for cutting and breaking above beads. The flanges of a rim may be battered down and roughened as a result of a tire being used deflated for a considerabie distance. When another tire is applied it is sure to cut above the beads. Tires carrying heavier loads than those for which they are designed may break at the beads where they are engaged by the clinchers of the rim. If rims become PIN TO HOLD SIDE BAR Popular Science Monthly rusted from water working in around the beads when the tires are run soft, or through neglected cuts in the tires, or from neglect to put proper fittings on the valve stem, the rust should be removed with \ N | SIDE EXTENSION BAR. FOR END OF FRAME “KEEL EXTENSION FOR ENDS OF FRAME, Detail of the parts for making the frame. in the construction of the canvas canoe emery paper and the rims painted with a coat of aluminum, graphite and oil. It is not uncommon for tires to be applied to rims of wrong size through a mistake as to dimensions. Sometimes a 36 by 4%-in. tire is placed on a 36 by 4-in. rim. The diameter of this rim is ap- proximately 28 in. and the diameter of the beads of the tire approximately 27 in. for a quick detachable type, and approximately 26 in. for the regular clincher type, there- fore it becomes necessary to stretch and strain the beads considerably. Again, the 414-in. beads are not constructed to fit a 4-in. rim, and will not engage properly in the clinchers. Good results cannot be secured when the beads are strained and crowded in this manner. Trick of Passing Cigarette Smoke Under Handkerchief LACE an ordinary china saucer over an empty glass tumbler and cover the whole affair with a handkerchief. Place the bundle on a table. Light a cigarette and blow a few rings of smoke towards the hidden tumbler. Then make a few magical passes. Remove the handkerchief and saucer and the smoke will be found _in the glass. To effect this you rub a few drops of hydrochloric acid on the inside of the glass and some ammonia on the saucer. The two fumes combined produce a vapor resembling cigarette smoke. a FE ; - A, B, and C are tees while F is a An Outboard Motor Made of Pipe and Fittings 3 A. SERVICEABLE and satisfactory out- board motor for a rowboat can be con- structed from a second-hand motor-cycle engine and ordinary pipe and fittings. Either the one-cylinder or a ‘‘twin’’ motor can be used, the only difference being in the mounting, which can be worked out by an amateur mechanic. While the stern transoms of rowboats vary somewhat in size, the dimensions herein given will suffice for the average boat. Any increase or decrease in the length of the upright supporting the motor can be adjusted by varying the length of one of its sectional parts, as shown in the drawing. There are two essential parts to its con- struction; the motor and pro- peller frame and the supporting board. Sections made of 1-in. pipe. The parts D and E are the same size cross 144-in. coupling witha in. threaded opening in the side at G. Thetotaldistance from the flange H to the bottom of E should be sufficient to im- merse the pro- peller-blade at least 3 in. under water, and the distance from G to the center of E must be at least 6 inches. The propeller J should be not over Io in. in diameter and of shallow pitch, to allow for the usual high speed of motorcycle engines. This is connected with a tool steel shaft revolving in the proper bushings in E. The other end of the shaft carries a large sprocket wheel J. The rudder hanger K is made of %-in piping by means of two straight pieces and an elbow. Fit the lower end with a tee to receive the bottom rudder-peg. A cor- responding piece of 14-in. pipe is threaded into G. Thread a small hole in one side of E and Semi-circu- A lar strap Popular Science Monthly The parts in detail for making and attaching a motor- cycle engine to a rowboat for an outboard motor 471 fit with a thumbscrew, then bore a %-in. hole about 2 in. under the flange on A and through the side of the pipe. The mounting of the motor must neces- sarily be left to the builder, as each of the varied types and makes of motors must be mounted in its own way. The semi- circular strap shown in the drawing can, however, be adapted to several different standard makes. In any case be sure that the small sprocket M is lined up with J and that the crankshaft is long enough and pinned, to accommodate a starting handle. The rudder N can be cut out of heavy galvanized sheet iron and riveted to the rudder rod O. This rod extends up as far as the base of the motor and is connected with the tiller by an elbow. The tiller is swung off at an angle so thatit turns either way to clear the motor and frame. Connect the two sprockets with a light motorcycle chain and cover well with heavy grease. Thesupporting board can be made of a piece of heavy oak 18 in. long and 12 in. wide. Curve the top edge to con-. form with the curve on the edge transom. Have a black- smith make two heavy iron brack- ets P and Q and fit the short ends with thumbscrews as shown. Bolt one bracket to each end of the board, counter- sinking the bolt-heads on the underside. The smaller brackets, R and S should be sufficiently heavy to hold the motor and frame by means of a steel pin passing through the holes in the ends of the brackets and the hole in the pipe A. Bend a short piece of I-in. pipe so that the curve will equal the arc made by swinging the suspended motor frame back and forth on the pin. Then secure the pipe to the board by means of a wide flange so it will travel through E. The motor can be held at any point along T by the thumb- screw, according to the pitch of the transom.—L. B. RoBBINs. Bracket clamp Making and Using a Casting Rod I.—The kind of material, size and fittings for a casting rod By Stillman Taylor may be quickly fashioned from almost any pliable wood, but the construction of a nicely balanced and flexible casting rod requires careful work- manship. No special skill is required, and as only a few common tools are needed, any boy of average ingenuity will be able to make a first class one that even an expert can use with satisfaction and which will compare favorably with the better class rods sold in the stores. A rod of this kind is somewhat expensive to buy, but as labor and retail profit represent almost two- thirds of its actual cost, a really fine rod may be built by the amateur at a comparatively small cost. N ROUGH-AND-READY fishing pole Tools and Materials The tools required are: a 4 or 5-in. block plane, a 14-in. single-cut mill file, a thin fine-tooth saw, a steel cabinet scraper, a small oilstone to keep the plane iron sharp and a few sheets of No. 1 and o sandpaper. To obtain the proper taper to the rod, a calipering tool of some kind is essential, for this work cannot be done by eye or by measuring with an ordinary rule. As the hand-made split bamboo rod possesses the greatest strength and elas- ticity with the least weight, it is regarded as the standard. But this material is so difficult to work, that only the more expert amateurs can succeed in making a first class rod of split bamboo. Different woods are used in rod making, but expert anglers prefer Bethabara, Greenheart, Dagama and Lancewood. Bethabara makes a fine rod, but it is hard to work; Greenheart is a fine material, but good quality stock is difficult to secure; Dagama possesses the strength and elasticity of the above, has a straighter grain, is free from knots, and does not warp readily, hence is the best for the amateur. Dagama stock in the square is easy to obtain at moderate cost. Lancewood is softer, full of small knots, and costs about the same as Dagama. Specifications for a Casting Rod Length 5 ft., weight about 6% oz. Handgrasp—cork. Rod tapered as fol- lows: Butt Joint 24 in. long, tapering from 15/32-in. to 19/64 inch at ferrule; Tips 3 ft. long, tapering from 17/64 inch at ferrule to 7/64 in. at tip; sections can be made same length if desired but the longer tip type is much better in action and makes a stronger rod for the same weight. Ma- terial—Dagama in square. Butt 2 ft. long by 54 in. square. Tips 3 ft. long by 3 in. square. Mountings 1 Shouldered and belted ferrule, 17/64 im. with closed end center for each tip. 1 Reel-seat, with straight hood, 34-inch. 1 Butt cap, I-in. 1 Taper, small end 15/32-in. 2 aris angle casting tops, 3/32-in. tip. 4 Narrow casting guides, % in. (2 for each tip.) 3 oes: — washers, 144 in. diameter, %-in. thick. (1 for each Before commencing work, draw a dia- gram giving the actual taper the full length of the rod, as shown in Fig. 1, with the cross stations spaced at 6-in. Ina piece of sheet zinc or brass, cut or file a series of slots in one edge to correspond to the diameters on the diagram, making the slots perfectly square, as in Fig. 2. With this gage check up the work. Before making an attempt to plane the stick, run the plane along it to find out which way the grain runs. Select one end for the butt of the rod, and drill a couple of small holes, about 4%-in. from the ends, making the second hole at right angles to the first, as shown in Fig. 3. Drive a brad or small finishing nail in one end of the bench, and hook the stick over the head. This holds the stick firmly so that it will not slip about during the planing. Plane the stick on four sides, from end to . end, until it is 4%4-in. square. Set the plane very fine, with the breaker-iron close to the edge of the plane-iron, and ground as sharp as possible. Draw cross lines on the 472 1s to find the center, and mark off the th of the hand-grasp. While a shorter p is sometimes preferred and used on tournament rods, the best length is a -double-grasp measuring 12 in. overall, including the taper and butt cap. Plane e stick with the grain until it is evenly . in the square, planing from butt to aoint, and check often with gage until the ct dimensions are obtained. The work of rounding up the stick is accomplished by using a length of common Yin. flooring with a groove in one edge. Plane the groove to roughly correspond Popular Science Monthly 473 chased punched to any desired diameter, but it isa simple thing to punch them by taking a common brass. ferrule 15/32-in. in diameter, sharpening the edge with a file. Fold several thicknesses of cloth over the end to make a pad for the hand, and rotate the cutter, back and forth, pressing down at the same time, to force the cutter through the cork. Do not hammer the cutter, for this will make a ragged hole. Corks of 11%-in. diameter and 44-in. thick are best, but the 4%- or %-in. thick corks obtainable from any druggist may be used. Cut the butt off square above the holes, a = DOUBLE GRIP FERRULE GUIDE TIP ROD MOUNTINGS > a a CENTRE Plan for the taper, gage and way of holding the rough wood for planing it to shape, together with _ the manner of cutting the handles from ordinary corks and the fittings for the entire rod with the taper of the rod. Nail or clamp the board with groove uppermost on the bench, and lay the stick in the groove. Plane off the four corners to make the stick octagon in form, then. take off these corners to make it sixteen-sided. Work very carefully, setting the plane very close and use the gage often to obtain the desired taper. The stick will now be almost round, and for the final rounding, make a scraper by filing grooves of different sizes in one edge of the steel cabinet scraper, shown in Fig. 4. As the bottom of the groove does the scraping, make it sharp by using a fine-cut file and hold it at right angles to the steel. With this little tool the edges are reduced to shape and sandpapering will make the rod smooth and free from hollow places. ‘The hand-grasp is fashioned from solid cork-washers. These corks may be pur- brush on a 4-in. band of liquid glue, and force the cork down in place. Coat the upper face of this cork and another section of the butt with glue, and force the second cork down against the first. Proceed in this manner until the grasp is of the desired length, 434 in. being about right for the lower grasp. The reel-seat is now fitted over a soft wooden core. This core may be purchased for a few cents, bored to any desired diameter, or made from white-pine. Bore a 15/32-in. hole in a stick of pine, and plane down to fit. The butt end of the core should be cut off 14 in. shorter than the reel-seat, at each end. As the ordinary reel-seat is rather long, cut it down to 4-in., reverse the hood and place it at the bottom end of the seat nearest the hand. When the core is a snug fit, give the upper surface of the cork and the butt it covers a 474 coat of glue, and push the core down into place. Coat the core with glue and push the reel-seat down over it, forcing the metal edge well into the cork to make a water- proof joint. The upper grasp is now formed on the butt above the reel-seat in the same manner as the lower grasp. Make this 21 in. long. When all corks are glued in place, lay the rod aside for 24 hours to harden, before attempting to shape it. The cork may be turned in a lathe, or roughly shaped with a sharp knife—a sloyd knife is a handy tool for this work—and sandpapered to make it smooth. A swelled or oval grasp is the best, and the writer prefers to form a ring 4-in. from the reel- seat to make a rest for the forefinger when casting, thus doing away with the metal finger hook. This and many other points may be seen by referring to the cut shown in Fig. 5 To prevent the reel-seat and butt-cap from turning, a small hole is drilled in the hooded end of the reel-seat, and on the edge of the butt-cap, and a small brass pin is driven in. To avoid weakening the wood, drive the pin in a little way, and file off flush. The tip is planed and rounded in exactly the same manner as the butt-joint. The metal taper which finishes off the upper hand grasp, the ferrule, closed-end centers and casting tops, are first carefully fitted by filing down the wood. Use ferrule cement to hold it in place, first melting the cement and then smearing a little on the wood and in the tube. The final varnishing is done after the guides and whippings are in place, but a thin coat of varnish should be brushed on and allowed to become thoroughly dry before the rod is whipped. This makes the wood waterproof beneath the whippings. Any good outside spar varnish may be used, or extra light coach varnish. Two guides are needed on a rod up to 6 ft. in length, the first being affixed to the tip 7 in. from the closed-end center, and the second 15 in. from the first. No guide is required on the short butt-joint of a casting rod, as the line renders more smoothly without it. Smooth off the rough spots of the bases of the guides with a fine file, and affix roughly in place by a few turns of common thread around one half of the base. Common sewing silk in size ‘‘A’’ may be used, but 00 size is better for small rods, This size can Popular Science Monthly only be obtained from a dealer in rod- — making or fly-tying supplies. green or red and yellow are the favored color combinations. Guides and whippings are put on with the invisible knot, shown in Fig. 6. A good way to wind the rod is to hold the spool of silk in one hand and rotate the rod with the other, letting the strands of silk coil closely against each other. A loop of waxed silk is inserted as shown, and through it the end of the whipping is carried beneath its coils to make a strong and invisible finish. Whip- pings may be. wound on at any desired distance, but many narrow turns will make a neater appearance than wide bands of color. Red and green, red and black, with an octasional edging of yellow, always prove satisfactory. When all windings are on, coat with orange shellac dissolved in alcohol to make a medium thick varnish. Do not shellac the rod, and let the silk dry well before varnishing the rod. A camel’s hair brush about %-in. wide answers for this work. If varnishing is done outside, select a warm, sunny day, otherwise do the work in a warm room, free from dust. Warm the varnish by putting the can in a dish of hot water before using. It will now spread smoothly, and every bit of the wood should be touched. Hang up to dry by the tip, and allow at least three days before brushing on the second and final coat. If the rod is much used, it isa good plan to brush on a third coat later on in the season. An Emergency Burning Glass Made of Match Crystals ae ES the need for a burning glass arises where one is not obtainable —for instance, in the woods to light a fire without matches. Two watch crystals, fitted together and filled with clear warm water, will prove very effective. Smear the edges with thick mud to keep the water from running out.—E. D. Rigs. The Trick of Burning a Lump of Sugar ed a match to an ordinary lump of sugar such as you find in little cubes for table use, and it will not burn. But, strange to say, if you cover the cube of sugar with cigar ashes and then apply a lighted match it will begin to burn. Red and | N these stirring times it is important that boys of all ages and men of military age should at least know some of the funda- mentals of military tactics. There is nothing more fundamental than marching. Every group of boys or men who wish to march should send for the U. S. Infantry Regulations, price 35c, to the Superin- tendent of Documents, Government Print- ing Office, Washington, D. C. Unfortu- nately, this excellent guide is not illustrated and its detailed descriptions are hard for the novice to understand. Then, too, al- though the matter is ar- ranged logically it is not in the best order for teaching a — beginner. The writer at- tempts here to describe and illustrate these fundamentals in the simplest and most progressive manner. Forming a Line The first thing to do with a group of marchers is to get them formed in a line. The instructor, or officer, calls out, ‘‘Fall in.”” At this, the men line-up in two lines, called ‘“‘ranks,’”’ one rank 40 in. back of the other and with the tallest at the right of the lines. (The tallest man in the front line; the next is directly back of him; the third tallest takes his place at the left of the tallest in the front rank; number four is back of number three, etc.) Those at the extreme right of the lines are the “guides.” At the instructor’s call “Fall in” the guides take their places facing the instructor. They stand erect, with left hand on the hip, fingers pointed down- ward, eyes straight to the front. The next in line take their places at the left of the guides so that their right arms just touch the left elbows of the guides. With left hand on hip and heads turned to right (called “‘eyes right”) they aline with the guides. All of the others “‘fall in’? in the same The positions of ‘‘Atten- tion” and ‘‘Eyes Right’”’ in forming a Company line Military Marching for Beginners The fundamentals of military marching illustrated to show the correct positions of a soldier in line By Albert B. Wegner manner. As soon as each one feels the one at his left touch his elbow he himself drops his elbow and turns his head to the front. The position that each now has is called *“‘Attention”’ in which he stands erect, heels together, shoulders back and down, feet at 45 deg. angle. The instructor now calls, “Right dress.” At this all place the left hand on the hip and turn eyes to right, holding that position until the instructor goes to the right of the lines to see if they are straight. If anyone is out of alinement he calls to him ‘Mr. . forward”’ or ‘‘backward”’ as the case may require. If several are out of alinement the instructor calls attention to that part of the line as “backward at the center,” or “forward at the left.” After the instructor is sat- isied that the lines are straight he commands “Front,’’ at which all face to front, dropping their hands into position of “‘Attention.”’ Simple Movements While Standing in Line The next things to learn are a few simple movements while in line. Nearly all commands are given in two parts. The first is the “prepar- atory command,” that tells the soldier what todo. The second is the ‘command of execution,’’ when he must begin the movement. There is always a pronounced pause between these commands so as to give all time to understand and prepare for the movement. “‘Parade—Rest.” At the command “Rest” step backward 6 in. with the right foot, the body weight on the right leg, the left knee slightly bent. At the same time place the thumb of the left hand between , the thumb and forefinger of the right hand, all fingers extended downward. “Company—Attention.” At the com- 475 476 mand ‘‘attention” take the position already described for attention. ‘‘Rest.’’ At this command the soldier may speak or do any- thing he likes as long as he keeps one foot on the line. ‘‘At Ease.’’ This is like “Rest” except that there must be no _ talking. “Fall out.’’ At this all may get out of line and do as they please; but they must remain near-by. After any of the above commands the in- structor must always bring the company to “attention” before giving them any other The first command is preparation and the second execution. The first two figures are at “Parade Rest,” the third, ‘“Hand—Salute,”’ the fourth, ‘“‘ ~ Popular Science Monthly is stationary stepping (no advance is made) — and is done by lifting the feet only about — 2 in. at each step. If the command is — given while standing still, start steppi with the left foot. ‘Forward—March.’ Step forward with the left foot first, 30 in. at each step, arms swinging naturally. “Company—Halt.”’ At the command “Halt,” given as either foot strikes the ground, step forward with the other foot and then bring the rear foot up to “atten- tion.”’ Take steps “Half step—March.”’ Rifle—Salute”’ and the last three are of the “Right Face” and “Left Face,” each one making a quarter turn to right or left in two counts command. After the command ‘“‘fall out” he must give them “‘fall in” to get them at “attention.” “Hand—Salute.”’ Raise the right hand smartly to the hat brim above the right eye with the forearm at an angle of 45 deg. then lower it smartly. ‘‘Rifle—Salute.” This command is given only when soldiers have rifles. The left forearm is raised hori- zontally across the body, the palm of the hand downward. “Right—Face.” Each one executes a quarter turn to right in two counts. On count 1 turn to right on the right heel and the left toes. On count 2 bring the left foot to “attention” (see picture). ‘‘Left—Face’”’ is done conversely. “About—Face.” This is a half turn and is always done to the right. After the com- mand ‘‘Face’”’ is given, place the right foot about 6 in. back of the left with toe of the right shoe on the ground. Now turn on the left heel and right toe half way about. This will bring the ‘heels together at “attention.’’ ‘Mark time—March.” This of only 15 in. each. ‘‘Backward—March.” March backward, start with the left foot, I5 in. at each step. When ‘“Company—- Halt’’ is given while marching backward execute it conversely to the marching for- ward. ‘Right step—March.” Step side- ward to right, right foot first, keeping the body to the front. (‘Left step” con- versely). ‘‘Double time—March.” This is the command to run. “Quick time— March.” At this command resume the ordinary marching time. The command ‘Halt’ or “Mark time” must be given if it is desired to change from marching forward to either backward or side step or the reverse. To keep the company marching in step the instructor counts almost continuously, ‘One, two, three, four,’’ and when he sees anyone out of step he calls to him, “‘Get step.” Each one is responsible for keeping in line. For this he must constantly give attention to those at his right. If the officer sees any who are out of alinement he calls to them, a a “Guide me Change step—March.” T - quick change of step by bringing the right _ soldiers keep in line but * right,” or “‘left’” as he desires. This means a foot up to the left and then stepping for- _ ward again with the left (or conversely). It is similar to the move- _ ment known among chil- _ dren as ‘‘skipping,’’ but, of course, done only once and not continuously as in skipping. “‘Route step —March.” In this the need not keep in step. Talking is allowed. ‘At ease—March.” This is like “route step’’ except that talking is not allowed. “By the right flank— March.” At this com- mand each one turns to the right and marches at right angles to the previous direction. The command “March” must be given as the right foot strikes the ground. Each one then steps forward and ‘turns on the ball of the left foot, then steps in the new direction with the right foot (see diagram). The converse when done to left. ‘To the rear —March.’’ The command ‘March’ must be given as the right foot strikes the ground.. Each one then ‘steps for- ward with the left foot; then turns to right on the balls of both feet; then steps forward in the op- posite direction with the left foot. (This is never done to left.) & “Right oblique— March.” Each one 4 makes an eighth turn | 7 to right and marches BX in an oblique direc- tion, starting with the left foot. If the command ‘‘Halt”’ is given while marching obliquely each one halts and then turns in the former marching direction. If the command ‘“Forward— March” is given while marching obliquely, all turn and march in the former direction. Popular Science Monthly “Left Face” is a half turn on the left heel and right toe This position is “Right Dress” with face to the right and the elbows touching the next person in line so he can feel it 477 Company Movements These maneuvers may be done with few or many men in line, but the following ones must have at least two squads (16 men) and it would be better to have four squads. _ After the company ex- ecutes ‘‘Fall-in,’” “Right dress,’ and ‘“‘Front’’ the instructor commands “Count off.’’ At this, beginning with the tallest men at the right of both lines they count in rota- tion ‘“‘One, two, three, four.”” The first four front line men together with their rear line men constitute the first “squad” (8 men to a squad); the second eight are the second squad, etc. ‘“‘Squads_ right— March.” At this com- mand No. 1 of the front rank of each squad ex- ecutes “Right face’’ and then ‘Mark time.’’ The others of the front rank execute ‘‘Left oblique’? and place them- selves beside No. 1 on the new alinement. No. 4 of the rear rank steps directly forward 4 steps, No. 3 three steps, while No. 2 and 1 follow No. 3. This brings them back of their cor- responding front line men upon whom they close to march- ing distance; then all eight without further command march forward in the new direction. (Con- versely to left.) “Right by squads— March.” This com- mand sounds much like the preceding one but is executed differently, although it too is used to bring the company from a line to a “Column of squads’’ (squads back of one another). At the command ‘March’ squad 1. marches directly forward. The other squads execute ‘‘Squads right’’ (de- scribed above) and then “Column left” 478 (described below) so as to follow after squad 1. (Conversely to left.) “Column right—March. ” This is a “follow-your- leader’ movement and may be done when the company is marching in column of squads, single file or by twos. When march- ing in columns of squads, squad I executes “Squads right’’; then as each of the other squads come to the place where squad 1 turned they also take the command, “Squads right,’’ so as to follow squad I. (Conversely to left.) ‘Squads right about —March.”’ two ‘Squads right” in succession so that they now march in the opposite direction. (Conversely on the command ‘Squads left about.’’) There are three ways of getting a column of squads into a line again. The simplest is to have them do “Squads left— March” (or “Squads right’). In the other two ways the line must come to a halt. ‘Left front into line—March.” The captain of the company commands, “Left front into line,’’ then waits a moment for the corporals of the squads to give their commands. Corporal of squad I commands, “Forward” (if the company is marching he does not give this command). At the 5 eae NP Mess foward march 1 1 wis | ! ! | Backward, mach. Popular Science Monthly In this each squad executes dress.”” After the squads have all thus 4 halted and dressed at the officer’s order, — the captain then commands “Front.” — (“Right front into line’ is done converse- ly, of course.) “On left into line—March.”’ The captain | of the company commands “On left into line,”’ and then waits until the corporals of the squads have given their commands. Corporal of squad 1 commands, ‘Right turn.” At the same time the other corporals command, “Forward.” Then the captain commands ‘‘March,”’ upon which each squad executes the command of its corporal. (‘‘Right turn” is executed as follows: No. 1 squad faces to right and takes ‘‘Half step.’”’ The rest of the front rank “Right oblique” without command and place themselves again to the left of No. 1. The rear rank do the same move- ment when they come to where squad 1 turned. Then when the rear rank has arrived at their proper distance back of the front rank the entire squad takes up the regular step of 30 inches, called “Quick step,” but without command.) Now the captain may at jf ‘oe s ig, | 1 if ! ! 1 1 ! ¥. oe, — PE ane aot cP fe € ( To the rear Qj By the right Changestep . flank “Forward March” starts with the left foot, and “Company Halt” as either foot strikes the ground; ‘Backward March” with the left foot; then ‘‘“Right Step March,” ‘‘To the Rear” and “‘Change Step” same time the corporals of the other squads command, ‘Left oblique.’”’ Then the captain commands, “March,” upon which each squad executes the command of its corporal. The captain may then at any time com- mand, ‘“Company—Halt,” upon which squad 1 only halts and its corporal com- mands, “Right dress.’”” When the other squads have marched a squad’s length left obliquely their corporal commands, ‘‘Right oblique—March.”” When they have come up to the left of squad 1 their corporal com- mands, “Squad—Halt,” and then, “Right | any time command, ‘‘Company—Halt,” upon which squad I only halts and their cor- poral commands, ‘‘Right dress.”” Each of the other squads marches forward until it gets a squad’s length beyond where its predeces- sor turned. Then the corporal commands, “Right turn—March.” When they come into line he commands, “‘Squad—Halt,”’ and then, ‘‘Right dress.”” Then when all squads are in line and ‘‘dressed” the captain commands, ‘‘Front.”’ “On right into line— March.” Squad I executes “Squads right.” Squad 2 peonspivies forward to a point one ‘squad’s distance beyond the point where “squad I turned, then it does ‘Squads right.” Each of the other squads thus goes beyond where its predecessor turned and _ then they also turn. At ‘“‘Company— E Halt” squad 1 halts. The other squads _ halt Popular Science Monthly 479 a quarter right wheel or swing of the entire company. No. 1 of squad I makes a “Right face’ and marks time. All of the others “‘Left oblique” until they get in line with him again; then the officer commands o ‘it “4 44! 440 40 06 ze and right dress 402 5q1 {7 re oe 44> z< N40 00 40 ze P Ruwe pase 592400 s¢ 40 ee +! lee 644040 8 +, 5 A * =» wie aasé 44 Awa lasaseses* ft 1 “? 8o2 5q-2 ar ‘ 3 Squads right 5 \asesasae tt | 4se wf aa odeqeat Mo 35 o> SESE Ae oe =: Ned ee ES 4 ihe S404 A945, a + soe Pease ee ¢ Left front ~\ C04 aaadas Ri ivr SB go AS ah : - .. ‘ight by Lax qalo pe Meer PO POTS into line NAME EF cg > file bt ee " aaa VRYEYEY) 4616 S515 sae 044s 44) Column right Sq.2 warwe Bd = 342 asasas es 3, a4! 4a ic 8 4 2 Squads left front 4 +4 hyd ¥) into line 54.1 tVRVEVEY, pe ean — 1G 14 12 10 '\asasases oe Oe The same orders executed in squads 44 444494 se of sixteen men each, showing their las aseses e< positions taken and lines of march 4 oa Yate eal : : Ee ed A040 40 9 5q2 “Forward—March”’ or ‘“‘Company—Halt,” Pes 46400444 F : eta te ag e On Hebi inte i as he wishes. To dismiss the company the fice Owe ao geting wee officer brings it to ‘‘Attention,’’ then com- VEYEVEVR EUR ULY mands ‘‘Dismissed.” $4 94 8494 06449494" When they comeup to Sq2: Sq where squad I halted. Burning Out Designs on a Right by squads. If while the com- pany is marching in columns of squads it is desired to get them into single file the command is, ‘‘Right by file—March.” At this Nos. 1 of squad 1 march directly forward. All the others halt. Nos. 2 of both ranks follow Nos. 1 of both ranks, etc. To form them into columns of squads again the command is “Squads left front into line—March.” Nos. 1 of each squad halts. The others “Left oblique” and take their places in the squad. “Right by twos—March’’ is the same type of formation as the above but marching in twos. To get them into file of squads the command is the same as above. Of course all of these may be done con- versely in the other direction. Marching in file and by twos is seldom used in the army because it takes too much time and room to be very useful, but in small groups it is a good variation. “Company—Right.” This maneuver is executed while in line formation and means Piece of Paper HIS sort of amusement can create con- siderable fun. This idea has been used many times in advertisements on post cards in this manner: A given point is lighted with the glowing end of your cigar or match and it causes-a trail of fire to slowly eat itself around the paper until it has traced out some name or design. The same thing can be done with a newspaper and any design or wording worked out such as ‘‘Merry Xmas,” ‘‘Welcome,”’ etc. Just outline the wording with a pointed brush dipped into a concentrated solution of potassium nitrate. Allow the paper to dry and all tracings will vanish. Mark the paper with a pencil so that the start of the line can be determined and then light it with a red hot poker, cigarette or something which will not make a flame to burn up the paper, but cause the invisible lines to burn out as the fire traces its arranged course. —CLARENCE T. HUBBARD. 480 Popular Science Monthly Knockdown Walls to Make a Portable Summer House UCH a popular demand has _ been created for knock-down building ma- terial for furniture, boats and the like, that some manufacturers are now furnish- ing ‘‘ready-made”’ houses, shipped in pieces, cut to lengths and marked so that a handy man can set one up or build it for a perma- nent home. The illustrations show such a house. It is not really a “ready-made” given in the plans. The siding and roofing material are also distinctive fea- tures of this house. The siding and roofing boards used are the small narrow kind. They are made to lap in the usual manner and are backed with canvas, like parquet flooring or the covering for a roll-top desk. In making the siding or roofing, the boards are attached to the canvas with the best grade of cabinet glue. This form of construction keeps the siding in the exact areas in which they are used on the building on FIN gX2xa STRAP IRON BRACES Ores A Ree > “oe FZ “SESS 2 K4 RAFTERS a PLATIE_ ESS. 24'C 106 se es S If at srunninc aaa | exeacl¢ CORNER POST R24” SILL BRACE SIDING WITH SCREWS TO STUDDING CLAPBOARDING ROLLED UP CLAPBOARDS OVERLAPPED es TO GIVE SECURITY FROM a | 3 THE PARTS UNDER LN STYLE OF HANDBOL SILLS AND ig > BEACH SAND, TAM WELL UNDER ALL PARTS 5) 2"x 5° RIDGE BOARDS TO FASTEN ROOFING SAMEAS SIDING 2'x4" RIDGE si “ANGLE IRON THROUGHOUT BLDG The studding, joist and sills are so constructed that they may be readily taken apart. The siding is put on canvas for rolling it up like a carpet so that the whole house is readily stored structure, but is designed so that the parts will fit together without any permanent fastenings, so that the owner may move it . from place to place as desired. It is especially adapted to the summer camper, or for the person who desires to live by the seashore during the hot months of the year. One of the features of the building con- struction is that the angle-irons used are permanently fastened to the wood pieces in such a manner that they aid in distinguish- ing the parts for their respective places. The size and dimensions of the parts are and they may be rolled up like carpet and stored for the winter. The method of holding the siding is clearly shown in the plans. It consists of applying the sections and clamping their ends at the corners with corner-boards, using bolts with lever-nuts. A few screws are put in here and there to keep the boards from warping. Long dock-bolts, run through each end of the sills and into the ground, keep the building rigid. The door and windows are of light mill stock, secured by hand-bolts to their frames. ae Popular Science Monthly at the Front Have you a brother, son or friend going to the front or to training camp? Make him .happy by sending him a good magazine PopuLar Science Monraty will give him all the new ideas in me- chanics and science. He will learn all the new war developments in airplanes, submarines, destroyers, machine guns and tanks. What magazine will be more’ eagerly read by the boy at the front? How to Send Popular Science Monthly Uncle Sam makes no extra charge for delivering magazines to our soldiers and sailors at thefront. You can send PopuLar SCIENCE Montuuy at the regular rates:— POt-OnG- year. x... $1.50 For six months,.... tS For three months... .40 _ Send us the name and complete designation of his division, regi- ment, company and organization —like this: Arthur J. Nichols, Company X, Infantry, American Expeditionary Forces. Popular Science Monthly, 239 Fourth Avenue, New York, N: Y. Aimed and Fired by Mechanism oe SA MCE ee = 5 The machine gun is nearing the zenith of its perfection. The coming weapon will be mechanically aimed, controlled and fired from a distance so that the crew may crouch in their dug-out, observe the foe through a periscope, and fire without exposing anything but a nerveless, fleshless mechanism of steel Popular Science Monthly 239 Fourth Avenue, New York City October, 1917 $1.50 Annually Vol. 91 No. 4 Is This the Machine-Gun of the Future? The men are concealed and the trigger is pulled by machine; the barrel is cooled like an automobile engine; the ammunition supply is continuous By Edward C. Crossman ACHINE guns talk in stutters— mechanism of the gun, so that the crew can M. operate it in safety, from a distance. staccato stutters. They can fire ; There comes now an inventor with the at the rate of six hundred shots per minute, but they can’t keep up the pace. Part of this failure is due to the fact that the ammunition containers are limited in capacity, part is due to the fact that the very first: rattle of shots jars the gun off the mark, unless the mark be a very large one. The gun must be ‘‘relaid,” before fire is resumed. Also, there is the fact that a continuous fire in any sort of machine-gun, water-cooled or air-cooled, would ruin the bore. The great heat of powder gases (more than four ‘thousand degrees) results in a washing away of the steel of the barrel in short order when the fire is continuous enough. The chief reason, however, for this break in fire continuity is the necessity for re-aiming the gun every twenty or thirty shots unless the mark is practically unmissable. —— What the machine-gun could use very nicely are these little things: A mount with possibly a recoil absorbing mechanism to pre-_ vent the gun from jarring off the mark; a better cooling system than the ones now used —in which the water boils away and the air doesn’t cool; a device for continuous fire for certain conditions; me- chanical control of the firing, the feeding, the ele- @A.S. Ford significant name of Ford—not Henry, how- ever—with some startling improvements for the machine-gun. The first one is a mechanically operated loading machine to .keep the belt of the gun filled all the time, regardless of its speed of fire and the duration thereof. The belt-loader is operated by the power of the machine on which the gun is mounted, this to be motorcycle, motor-tricycle, automo- bile, airplane or other power vehicle. The second is a circulating water-cooling system, & Ja automobile, in which the water passes from the jacket around the gun- barrel to a regular automobile radiator, which in turn is cooled by a fan driven by the power that operates the loading mechanism and which in turn is merely the power plant of the car. A centrifugal pump makes the water move, although it would surely thermo-siphon hur- riedly if this system were used instead of the pump. The third startler is the fact that the gun is de- signed to be an integral part of its car- riage, which isa gas engine pro- pelled — vehicle. Perhaps thisidea was borrowed from the fight- ing airplane, in which the ma- chine gun is rig- idly mounted to vating, and the traversing The belt-loader on this machine-gun is operated by power from the motorcycle on which it is mounted 483 fire through the propeller. 484 Popular Science Monthly If You Lisp or Stammer Train Your-_ graphic plate only one such impression, or self with a Mirror or a Candle ISPING and image, can be obtained. With the motion picture film, however, a fresh’ piece of film is continually ex- stammering ff are separate 1mper- fections of speech which require en- tirely different treatment. Lispers, ~for in- stance, can be cured in a short time by tongue and palate gymnastics. They “lithp” simply be- cause they do not work their tongue and palate proper- ly. By making the child speak before a mirror, however, the teacher can correct these mistakes. Stammering is a nervous disorder which cannot be cured so easily. The pupil involuntarily applies too much force at certain parts of the vocal organs, caus- ing the stuttering and a sputtering with which we allare familiar. Thecureis to relieve the over-worked parts by distributing the energy evenly. This is learned by pronouncing certain flowing sounds in front of a candle until the flame does not flicker. The Original Motion Picture Film— ‘It Is in the Human Eye HAT the human eye and the photo- graphic lens are very much alike in design and operation is a well known fact. Above: Practising breath control with a candle flame. Below: Tongue and palate gymnastics -before a mirror posed to the lens. Just such an ar- rangement exists in the human eye. An emulsion called vis- ual purple acts as a film of great lati- tude, renewing it- self as soon as it is struck by the light and discolored. . It adapts itself to various intensities of light, protecting the retina from too brilliant a glare at all times. A Self-Inflicted Tug- of-War to Increase Your Height O increase the height by a stretching pro- cess, to vivify the spine and stimulate the nerves— these are the purposes of ‘an odd machine known as the pandiculator, invented by a chiropractic specialist for use in the practice of that method of treatment. The apparatus is simple, consisting of a couch with a headpiece and a foot rest that can be extended by the operation of a cog and. ratchet device at the side. The person who wishes to. increase his or her height is fastened in the machine and the stretching is done by turning the ratchet. It is extremely doubtful if the machine illustrated could do more than exercise the If you look through a photographic lens you neck and abdominal muscles. will see nothing clearly. To Ss perceive the image a piece of ground glass or a plate of film is necessary. plate is a“ piece of plain glass which acts as a support for an emulsion. This emulsion decomposes when struck by light, and the decomposition is made visible by. a process called develop- ment. With an ordinary photo- After you are strapped in the machine you stretch yourself as strenuously as you like by pulling the ratchet device at the side Popular Science Monthly Fiber Containers Take the Place of Tin Cans for Preserved Foods IN is scarce. Imports have decreased, due to reduced production and poorer shipping facilities. ‘‘Ready-to-eat’’ foods are prepared in the containers; hence they require tin cans. Many foods, like ripe olives, jams, and spices, can be packed as well in glass jars. But the price of glass is steadily rising. To conserve glass and tin, containers of fiber or paper are being made in increas- ‘ingly large quantities. They come in Various sizes and shapes adapted to differ- ent uses. Most of them are coated with paraffin, which prevents leakage and helps to make the container airtight and to keep it board-stiff. Fiber containers can be recommended for cream, oysters, syrups, dried fruits, jellies, mincemeat, horseradish, pickles, deviled ham, chicken, vinegar, mustard, sauer- kraut and olives. The Umbrella Hat—It Was Invented Years Ago by an American HE umbrella hat is not a recent inven- tion, but was familiar years ago to the residents of Seattle, as the particular head- gear of Robert W. Patten. He was a picturesque figure on the city streets, and he always wore the hat which. he invented while mining in Mexico. The hat:is mounted on a frame which fits closely around the head and branches out in ribs like those of an umbrella. Originally, netting was draped around it to keep off the mosquitoes. The umbrella portion could be tilted to any angle. Although not as wide as an ordinary umbrella, when used with an all- enveloping rain-coat, the umbrella hat keeps off the rain as well as if it were larger. The idea has been adopted in a modified de- The umbrella hat can be tilted With this combination knife and fork a wounded man can cut and eat his food without assistance A Combination Knife and Fork for the Wounded ‘VEN the ordinary tableware is under- going changes and improvements to meet the needs of the soldiers who have been wounded. The accompanying illus- tration shows a combination knife and fork which will enable a man to eat in comfort without hav- ing to call on some one else to cut up his food. The knife blade is equip- ped with a bone handle at one end, and at the other it curves up and around and ends in four prongs like those of an ordinary fork. The usefulness of the knife for the purpose is evident. Below the prongs is a broad flat portion slightly dented in, to prevent the food from slipping off. This also serves as a spoon, so that in reality the implement is a combina- tion of knife, fork and spoon. It may be used for everything but soup. gree by farmers. at any angle to keep off the sun The November issue of Popular Science Monthly will be on sale on all newsstands, Wednesday, October tenth (West of the Rocky Mountains, October twentieth). A refrigerator for one of the Na- tional Guard units camped in the East. It is a hand-made affair, constructed of boards and divided into three roomy compartments in which food of all descriptions is stored. . The ice is kept in the lower section—when there is any ice. The interior is lined with odds and ends of sheet metal The army “water cow,” York. The bag is first soaked in water and then filled with water. The sun and wind do the rest by starting evaporation ” A knapsack refrigerator for the soldier:to carry on his back. The cold com- partment is lined _ with sheet metal and water cools the contents on the _ evaporation principle. . It is not as heavy asit looks, being made of light weight material. The articles car- ried’ in’ it are such as . > «can be soon disposed ‘of used . by, National Guardsmen in New 486 Training a Horse for One of the Finest Ser- vices in the World—The New York Mounted Police Teaching a re- cruit in the busi- ness of stopping arunaway. The policeman’s mount must run even faster than the frightened animal in order to head him off SS SSS SAA Only men who show a marked aptitude for riding and only horses which respond readily to the rigid course of training, are accepted for the mounted divi- sion. This one is a bit unruly Photos © Int. Film Serv. Throwing a horse so that a veterincry may work on its feet and legs. The rope is attached to one front and one rear foot, and passed through a ring in the surcingle An Ounce of Prevention Is Worth a -\Pound of Cure 6 piidison 4 Photos © Int. Film Serv. Above: Each anchor weighs a ton. A wheeled lever-hoist is necessary to lift the ‘“‘sinkers’”— as they are called by the sailcrs Securing the bell anchors to the bottom cables In oval above: Spreading the net. The tmesh- . Of the nets to be used as submarine protection €s are very fine and are arranged ten feet apart 488 The Anti-Submarine Nets Our ‘Tars- Are Making © Photos Int. Fiim Serv. Above: Having been shipped on giant spools, the nets are ready to be rolled upon the barges which will carry them out to sea Two members of the Naval Reserve clamping the mesh joints together, the completion of the first stage of net work Barrels and tanks which will buoy up the finished nets at some strategic point. In the foreground are seen the anchors Cee sd ‘ (me © lesen a wr, If All the Allies’ Army Blankets Were Rolled Together, — End to End! Imagine yourself slowly running your eyes up the four hundred and fifty-one feet of the great Khufu pyramid in Egypt. Do not stop at the top, but picture if you can, seven more pyramids of equal height placed one upon the other above the real one. In back of these imagine a great roll of wool and cotton whose prodigious diameter stretches from the ground to the peak of the top- most pyramid. Your mental picture will be like this one, and it will represent the miles of blankets that have been used in the equipment of the Allied armies from the beginning of the war until our entrance into it. And this enormous amount of material is only cne item of the equipment! Such comparisons are useful in bringing home to the lay mind some idea of the total cost cf the war in dollars and cents as well as in the consumption of products and the output of ‘factories 490 What It Means to Feed, Shoe and Clothe the Armies of the Allies The food that was trans- ported during the first thirty months of the war to the Allies’ would fill six lines of .freight cars, stretching from the State of Washington to Florida Our first equipment order was for four million two hundred thousand pairs of shoes. Ifa pair could be made that number of times the size of the ordinary pair, it could “press under foot” all Germany and Austria Up to April of this year, the Allies had used up six hundred and thirty-three million yards of cloth in the making of their shirts and uni- forms. Such a strip could encircle the earth fifteen times, covering about 375,000 miles 491 ¢ Sahara with Airplanes isterin ols the Bl France Patr Jodoor, & Sutsoy ynoy}M ‘souvIy se e913 se SoUIT} 99IY) “JOLNsIP ajoyM ayy [oryed 04 o]qGe us3q SAY YUoIY 943 IN ‘YyOUdIY 3G} Jsurese sue dn Surye} soqis} SIpeusou yeiaAds ‘UOJ Sy} UL Sye2IQ}NO [eJaAas UIG0q aAbY 2394, “SI[EM Ysty YPM poyVJoj ose sosnoy 94} |e jsourye yey} 99S ]]IM Nod pue Ajasojo Yoo ‘suejdire ue wo soweny jo uMo} 2y3 jo Jzed pue jlasoq ereyeg ay} Jo uaxe} ydesZ0j0yd s[qeyreulsl wv poomlepul) pu’ poomiepuy GO) * ESE Mbdidddddddupldlteterpyyy JCI Led Li iiecccoczlcccccczczccccqcczQed LL LLL XN & \ N ( MMMM 492 Indian Art Is Not Limited to Basketry The Indians of South America are so intermixed with the Spanish and other Europeans that there are few true totype. But in the mountain regions there are many reminders of the primitive tribes. At left is shown a group of images of Colombian peasants carved from Seiba wood. These little figures are made in great quantities by the young gir s of : Bogota, Colombia. oo ae They are very ac- ‘ curate in details of Shs costume and expres- tee sion. Types such as these are com- mon among the tribes in portions of the upper Andes Photos @ Brown and Dawson The South American Indians are adept. at making pictures out of feathers. Above is shown a bird scene fashioned entirely from feathers of tropical birds. It represents twelve days’ steady work At left: Statue of a Colombian peasant woman. It is molded from a peculiarly hard wax which does not melt even-in the tropical heat. - The costume— even the cigar—is typical of the Chibcha Indians 493 Food—Food—Everywhere If We Painting a life-like model of a snake— not for exhibition in a museum but for illustrating the many foods we don’t touch. Shall we ever eat snakes? Once upon a time ox-tails and feet were considered useless calves’ Lance, oN Above are some unutilized foods of our seashore —dulse, kelp, mussels, squid, periwinkle and sand collar snail. Ever eat any of them? If they tasted good rec- ommend them By Amer, Mus Nat. Hist. reese - MMMM pictures of réal fruit framed in baking tins 494 This artist of the kitchen makes pleasing Would Only Eat Can a man be well fed on twenty-five cents a day? Above are three tables set for breakfast, luncheon and dinner at a total cost of twen- ty-five cents Baie opi & JeAO Ajpides speoids uoTeIBeyuoD oy} pue ‘JoJaWLIP Ul Js29J DAY Jnoqe pue Suc; 3095 AYR st pajzel[oid aueYy sy ‘sTIO Suneoriqny] pue Suruinqg jo din}xTUI & Y}IM jyey Jomo] oy} pue uasospAy passosduroo yyM poly jrey soddn oyj3—sjsed om} OJUI popraAIp st JapuyAd oy “SUIs9q 49e}}e 34} DIOJoq pozYysT] ‘YOM & poyoeze SI YOIYM 0} 9[zzou & pue ‘adid ssoy [eeu e& ‘yDeq S,JdIPjos 943 uO pedde.ns JapurjAd yejyoure jo sjsisuod snjeredde syy ‘ary pmbiy yyWM yo"We UeUIION e Buedo1 sdoo youary jo ydesZ0j0yd a[qeyseulss y woqIeH pus jepsy © <9) =) ia] (aa) © wet) &, =) vo Bn ne O = A mirror carefully A choke coil which gives a adjusted like the good strong illumination at one at the side of seven miles an hour without this car will pre- burning out the lights when vent rear collisions going at twenty-five miles longs. Below: Rubber foot pedals are easy on the shoes and sometimes prevent your foot slipping when you _ apply the brakes quickly. ° They are said to reduce __— vibration QA WWW0 vo 6 -,WW0— WW ". SGV GQ ee v5.00 0 D0 yw 76”: 0) FlaT®»’5 j Fe Hand guards for doors eliminate ugly spots on the woodwork and break up the. straight line at the side of the car nnn SOWA RA bp Rubber running boards are very convenient — at fifteen dollars a pair, thank you. But they wear well and are very easily kept clean Here we have one of the few men who know where every Ford accessory be- He is showing you a decoy in- strument board to humiliate your pocketbook, and a new- fangled automatic gage de- vice for the gasoline tank A good shock absorber which prevents you from bouncing out of the car when it strikes a partic- ularly resistant obstacle. It is probcbl7 the sim- plest device for the pur- pose on the market Dolling Up Your Ford Every carbureter is better than the Ford one—so the papers say. This: one gives 37 miles on a ‘gallon and revels in kerosene A runabout with $311.50 worth of accessories on it. It runs under its own power! At right: A slip to go between the windshield and the top, to prevent drafts from sailing down The Ford radiator cap is too typically Ford, and burns the hands at times. Better replace it with a cap of this type The robe rail costs from seventy-five cents to $1.35 and it keeps the interior of the car neat the necks of folks in the tonneau 497 MUL A set of gears for the driveshaft. It gives four speeds forward, a lower high gear than the Ford high and a lower low than the Ford low The demountable rim graft —a pound of weight below the springs is’as bad on tires as four pounds above Photos © Brown and Dawson. Loading one of our coast defense guns. Coast artillery is charged with protecting places of great strategic or commercial im- portance against naval attacks At left: The breech of the big gun thrown open to receive a shell, several of which are mounted on trucks specially pro- vided for that particular work Is the Order Given to the Coast Artilleryman A big gun at the moment of firing. It has been elevated into position before firing, and immediately afterward it falls back out of sight on its supporting members. The F two-ton shell it has hurled off into space can penetrate the thickest armor of any battleship that may dare to poke its nose within a dozen miles of our coast “Tactics change every ten years,” said Napoleon. Before the war our coast artillery was practising at ten thousand yards; now the range has developed into twenty thousand yards and more. The energy nece-- sary to fire a shot from the gun in the picture con- tinued from the preceding page would project your two-ton automobile twenty-seven miles in‘less than twice as many seconds 499 ilding the Foundation for a Wasp Empire Bu Spesut pue Asuoy uo paj ose BAe] dy} pue yo yo}ey Apypomb ssoyy, *yoes ut 339 ue she] pue soo PoPpIs-xIs JYBI9 JO XIs suorysey eyS = “ssouBISqns 91qe}939A Wo’ sMef s,dsem oy} ‘ul dn poyxiom soded wo peyon.ysuod SI jsou JsIy oy ‘“Sutids jo shep ysiy oy} Sut inp sosdura dsem jo suonepunoj oy} Avy pue [yey oy} Ul azeuJaqiy susenb syy “3ysou Burids ysry soy uodn Zuryiom dsem usang : uOsMEC, pus uaorg ©) 500 The First Stage in the Life of a Wasp ees © Brown and Dawson Queen in the act of laying an egg in a newly constructed cell. The nest of this type of wasp is usually found suspended under the overhanging reofs of buildings. The larvae remain in the cells until they reach the “pupa”.stage. Then the cell is sealed up with the pupa inside, It evolves finally as a young wasp or “worker” 51 Three Stages of Growth in a Wasp Colony The front of a wasp’s nest is seen at the left. The nest has grown to an empire, many broods having been raised and each in turn having la- bored to increase the colony. In each of the cells the face of a young wasp almost developed peers out Below are shown cells of the wasp’s nest, cut open to reveal the eggs as deposited by the Queen. The cells of a nest are not allowed to remain idle; as soon as cne wasp emerges, the cell is cleaned out for another egg. The young wasps are the workers MLL © Brown and Dawson SS Section of a wasp’s nest showing on the left a young wasp still in the feeding stage, and on the right a wasp that is nearly ready to issue - into the world and take up the work of the empire. In the fall the nest grows to great proportions. At length the old Queen dies, and the young wasps fly away from the home 502 Choosing Your Suit of Air A problem in scientific ventilation and how it is being solved by some interesting experiments By George T. Palmer Chief of Investigating Staff, New York State Commission on Ventilation Arrangements for measuring and distributing the flow of air in aschoolroom. The room seems to be free from air-consumers, but it is not. Under the conical hoods are lighted candles which give off heat and use up oxygen at about the same rate as an equal number of pupils PROPER “suit of air” is just as important as a serviceable suit of clothes. A “suit of air’ is not imaginary. Itisa fact. Our bodies are entirely surrounded by air. Out of doors we can make the air fit us pretty well by taking off or putting on more clothes, or by moving about if neces- sary to keep warm. Indoors, however, we have not so many privileges. This finding of the proper suit of air does not sound so difficult; -for we are familiar with electric desk fans in summer and large ventilating blower fans in winter which blow large volumes of air through an entire building. But if the problem were simple our workshops and places of amusement would not have air that makes us feel bad. The New York State Commission’ on Ventilation is engaged in studying this problem of ill-fitting air-suits. The funds to support the work are given by the New York Association for Improving the Condi- tion of the Poor. | This Commission believes that the way to improve on the ventilation of our buildings is to find out first what good ventilation is, to find out what the human body in its different activ- ities needs. With these facts known, it is then necessary to learn how to produce the good conditions and avoid the bed. What Is Good Ventilation? The first step in finding out what is good ventilation, is to measure the effect of different kinds of air on people. The body is likened to a steam engine or an automobile... The appropriate fuel. is supplied and the combustion of this fuel with oxygen produces energy, some of 503 ; 504 which appears as heat and some of which appears as motion. The body can be thought of as an engine with steam up, with the fires constantly burning while life lasts. This fire keeps the body very close to a temperature around 98 or 99 degrees Fahrenheit, which is much above the average outdoor temperature. Now with the fire con- stantly burning, it is evi- dent that heat is con- tinually being given off. Through the lungs the gaseous products of combustion, carbon di- oxide (and along with this a good deal of oxy- gen also, for the body uses only a part of the oxygen that is breathed in), are also constantly thrown off. But the body keeps its temperature con- stant by means of a wonder- fully complicated temperature control system. The Commission set about studying the effect of -the Popular Science Monthly Measuring the size of the breathing spaces in the nostrils by breathing gently on a cold metal plate down on paper just how they felt. But their opinions on personal comfort were not _ sufficient. It is also desirable to. know whether people can do better work under one condition than they can under another, not merely physical work, but mental work, And are they as healthy in one condition as they are in another? Is it variations in temperature that have the greatest influence on health and _ efficiency? Is it variations in mois- ture? Nearly four years have been spent in getting the answers to these most important questions. Over two hundred different peo- ple—men and women, col- lege students, clerks, typists, truck drivers, boiler makers, firemen, the robust and the weak, the large and the small, the clean and the unclean, have spent some portion of their time—from one day to various factors of the air on - [1 this heat. eliminating, gas Zone producing, human engine by [4yrgpn placing people, as shown in 166 one of the accompanying pic- AO tures, in a specially built ex- Y periment chamber, a room connected with steam coils, a A 4 A713 refrigerating plant, moisture producing apparatus, ventil- ating fans and various other devices for altering the condi- tion of the air. The great advantage of this experiment chamber over the ordinary room is that each of the various air factors—temperature, moisture, etc.—can be controlled and varied at will. . In a crowded theater, for instance, as the air gets warmer it also gets more moist and begins to have a “‘crowd’”’ odor. In the experiment chamber the temperature can be hotter while the moisture remains the same, or the moisture can be increased while keeping the temperature the same. In this way each of these various factors can be separated and studied independently. The Commission paid people regular salaries to stay in this experiment chamber. First these people, or subjects, would be _exposed to one condition for a day or a D le 5 The overheated air room has caused the bone in one nostril six weeks—within the experi- ment chamber. To observe and study the effects of the various air factors on these subjects the Commission has employed a corp of trained observers, —psychologists, | physicians, physiologists, nie chemists, sanitarians, bacteri- ologists, and engineers who have recorded with scientific exactness each shade of differ- ence observed in the separate individuals, met a: rz to swell - The Findings of the Jury of Specialists In the first place, they have found that so long as the room was kept cool, that so long as the temperature was not allowed to rise, it did not make much difference whether or not a plentiful supply of fresh air was supplied to the chamber. = week and then to another. They wrote Even when the subjects spent a whole day and six days in succession in the unaired chamber, breathing air that con- tained the accumulated products of the breath, they did as good mental work, felt just as happy, and did as much physical work as they did when the ventilating fans were constantly changing the air. Further- more, the most careful observations of the a= ~ “Witt this does condition of the body failed to show any harmful effects. The only indication of any depressing effect of breathing this confined and several times used air was that about five per cent less food was eaten. The decreased appetite was not due to any accumulation of the gas carbon di- oxide; for, when large quantities of carbon dioxide from a tank were added to the fresh air being blown into the room, the appetite was not reduced at all. It is im- probable that any poison from the breath affected the appetite, for many elaborate experiments on this point have failed to show the existence of any such poison in the human breath. It is possible that what affected the appetite adversely was a slight odor of sweaty clothes or decaying teeth, which odors are the natural out- come of the continued oc- cupancy of an unventilated room. The above sia tement should be care- fully scruti- nized and re- read. This finding does not mean that fresh air is. of no value. Fresh air is of the - utmost value, ascan beshown by a wealth of examples. imply is that the good ef- fects of fresh _ air are due more to one of its components —cool temperature—than to another com- ponent, chemical purity. Conversely, this finding indicates that the unrefreshened air of an occupied room whose temperature is not allowed to get too high, does not produce unfavorable effects on the mind, the comfort, or the various organs of the body. On the other hand, that this re-breathed air, even though cool, is not entirely with- out some effect, is indicated by the fact that the subjects unconsciously ate slightly Popular Science Monthly heart and circulation and the general Testing the pulse and blood pressure of workers and of reclining subjects under the same air conditions 505 less. In this connection it should be borne in mind that in producing even this slight effect on the appetite the accumulation of re-breathed air in this experiment chamber was from three to. twelve times as great as that found in an ordinary badly ventilated schoolroom. Compare this experience as to re- breathed air with the effects produced by over-heating, even slight over-heating; that is, an increase of temperature from 68 to 75 degrees. At these temperatures, and with the subjects dressed for fall or winter weather, the heart beats faster; the body cannot get rid of its heat as readily and the heat accumulates thereby, causing the body temperature to rise sometimes a degree or more. The subjects feel uncom- fortably warm; they do less physical work. One experi- ment showed . 15 per cent less work done at 75 than at 68 degrees. The appetite, how- ever, remained about the same and the mental work was un- affected even by air hot enough to cause profuse perspiration and very evi- dent discom- fort. ’ As compared with the chem- ical purity of the air, then, the variations in temperature have been found to pro- duce a very much more pronounced effect. The Nose Is a Pretty Good Judge Now, in addition to these effects, over- heated air, or air which is warm enough to cause people, as they are dressed, to feel uncomfortably warm, also produ-es a very evident effect on the nose. There is a most peculiar spongy bone in each nostril, called the turbinate bone. This bone has the power of expanding or contracting. When it contracts so as to occupy very little space there is a wide clear passage to 506 breathe through, but when it expands it may become large enough to close up com- pletely the breathing space in that nostril. lt was found that warm air, from 80 to 90 degrees, has a tendency to make this turbinate bone expand. Warm, moist air is apparently more : likely to do this than warm dry air. The man in one of the pictures is breath- ing on a cold, shiny metal plate. The moisture in his breath condenses, is turned into water droplets on the plate and .makes two little im- pressions whose size gives some idea of the breathing space. The black areas of the chart show that in this case the heated air of the room caused the turbinate bone in one nostril to expand considerably more than ‘that in the other nostril. While this appreciably lessened his breathing space he was not so oppressed by the closeness of the room as he would have been if both nostrils had been affected to the same extent. This fact is of importance because this swollen or congested condition of the turbinates and adjoining membrane, accompanied as it is by increased secretion, has a good deal to do with catching of colds. The physical sensation resulting is like that of a cold in the head. Why Even Warm Winds Are Cooling The reader may be tempted to inquire why, if heat has such a pronounced effect on the body, we are not all sick in the summer time. The answer is that we are not all sick in the hot summer weather simply because we have means of keeping our bodies cool—as cool or actually cooler than when indoors in the winter time. In the first place the body produces less heat in summer. In the second place, we wear lighter weight clothing in summer. By reason of the excessively high tem- perature of the air about us in summer— 80 to 100 degrees—our bodies are caused to perspire much more freely than is the case in an atmosphere of 70 degrees indoors Popular Science Monthly This man’s body is exposed to the temperature Of one room and his head to that of another. He is breath- ing the air from the first room. The temperature of his head is being taken with an attached thermometer. The experiment determine; exactly which part of the body is most af- fected by changes of temperature in the winter. Our clothing becomes damp — on absorbing this moisture from the skin. Now, when a current of air passes over a damp cloth it takes moisture away from the cloth—or causes water to evaporate from the cloth. Heat is used up in converting water or moisture into water vapor. Place a damp cloth on the bulb of an ordinary thermom- eter—the cloth need not be cold—and expose this to a breeze. You will observe that the thermometer imme- diately indicates a lower temperature. This is just what happens to the body. When a breeze—even though it bea hot breeze —blows across damp skin or damp clothes it extracts heat. The body is exposed more frequently to breezes in the summer; for we are out of doors more and even when indoors we have the windows wide open. This outdoor air is only very slightly purer chemically than the cool indoor air oi winter. It is the cooling effect—not, however, cool enough to be chilling—which constitutes refreshment. The ventilating engineer has got to know the causes of “freshness.” Determining whether a student can do bet- ter mental work in a cool or a: warm room Popular Science Monthly What a Life of Cap- tivity Does to the Lion ~+€C*OME interesting facts v4 have been revealed _ from a study showing the differences between wild- killed lions and those which _ had died in the National Zoological Park in Wash- ington. It was found that captivity changes the nor- ‘mal buff color of the lion to a darker color, the color deepening for each succes- sive moult for five years at least. Lions captured ~ young and reared in cap- tivity had muscles little developed, and as a result their skulls showed a mark- ed difference from those of wild-killed lions. This was due, say the investigators, to the fact that the skulls of lions are greatly influenced by muscular activity. Using muscles develops them; and disuse de- ' stroys. material A Stylish New Blanket-Coat for . the Baby Lamb HE greatest obstacle which stands in the way of providing very young. or new-born lambs with artificial coats or blankets to protect them from sudden changes in temperature or from storms until their own coats are heavy enough to serve the purpose, is _the fact that the covering “material is likely to de- “stroy the lamb odor by _ which the mother recog- - nizes her offspring. The blanket shown in the illustration leaves enough of the _lamb’s neck and body exposed to satisfy the _ mother as to the lamb’s _ _ identity, and at the same ' time covers the vital por- _tions of the body snugly. It is composed of a water-' ° proof outer canvas, with a soft woolen lining. Four re Conical Absorbent fee oH The centrifugal force generated by the rotation of the shell spreads the flaming gasoline in all directions Cartridge ; Firing Shells Charged with Gasoline Which Ignites on Impact recess en- gages base of torch N their great attack upon Messines Ridge, the British brought into play a new weapon, the inflammable shell. ‘‘We didn’t use gas in the attack,” said one correspondent, “‘but every known form of offensive weapon I think we did supply, including a new horror known in the army as ‘oil cans,’ or ‘boiling oil.” These on concussion burst and scattered conflagration over a wide area. We know from the prisoners taken that they caused terror and did an immense amount of harm.” Light on the nature of these flaming projectiles is given by an American patent which was issued to Henry Dean, of Michigan, early in the war. A cham- ber containing high-ex- plosive powder is situ- ‘ated in back of the solid nose of the shell and right in front of the firing torch. Sur- rounding this highly- inflammable torch is the charge of gasoline which takes up by far the “greatest portion of the interior of the projectile. Thus,when the nose of the shell strikes against the The blanket is made of waterproof outer trench wall,the concussion elastic loops fasten it on. canvas lined with soft woolen material sets off the gunpowder. 7 = New Jobs for the Motor-Truck and New q pa ra a ty ig How strong is a truck? Here is one that pulled a 154-ton railway engine CENTRAL - ELECTRODE PORCELAI A cleaner for the wind- The moving shield which ball in this cleans both spark plug the top and An old wood elevator and its frame- prevents ac- bottom glass work serve as an improvised garage cumulation of carbon 5 se: ciate Even on a wet;slippery street, this four-wheel motor-truck was able to pull a disabled twenty-five- ton trolley car up a hill with a twenty per cent grade. The passengers preferred to walk 508 3 4 ~ Additions to the List of Accessories “At left: A portable Attached to the rae electric. valve diator cap, this grinder fitted small fan revolved with a motor- by the wind keeps driven drill tool the water cool Arf Ys An automobile railway in Porto Rico. ates 9 Flanged wheels take the place of tires sO ge At left: Steel skids to ele- vate an auto- mobile, sup- plant the re- Oats: prt Flags which spin around like a _ pin wheel are mounted on the radiator An automobile glove with “wings” to This demounting device is a take in coat sleeve and keep it clean flanged sleeve over the hub War Work for Motor-Trucks A motor ambulance which carries four stretchers, a medi- cine cabinet, and a re- aie sanity serve supply of gasoline The army kitchen motorized. It was pre- sented to New York National Guardsmen Above: A wind shield glare dimmer which this vulcanizer is fur- consists of a circular nished by a combust- piece of ible disk colored in a metal ~ container glass Sal Below: The heat of Utilizing the hollow space in the center of stored tires for a tool chest This repairshop automobile derrick which is made of light angle-irons will lift three tons New Tools for the Automobile Repairman Soa) Ee Doing a locomotive’s work. The automobile pulls two freight cars with loads of from two to twelve tons At left: A new cork insert Ford fan belt At right: Motor- cycle padlock locks the rear _ driving sprocket to the car frame A new gas saver increases the speed of the car and prevents the formation of carbon neh SRASS UU LUIIOIITLE errr A trouble light with a flexible handle for 2 carrying. it : into the The method of driving a new wire The latest oddity in motorcycles— hard-to- wheel is by means of six powerful drive the motor is located in front, and reach places studs on inner drive flange of hub direct drive is obtained by friction 511 Turning a Car in Its Own Length us ] It is a mere matter of lifting it and swinging it around on its rear wheels HE parking problem would be par- tially solved by the adoption of the device illustrated, which enables a car to turn around in its own length. It consists of a small wheel carried cross- wise of the car between the front of the motor and the permits the gas to force the oil in the system. through a pipe leading to the tops of the two vertical cylinders carrying the lifting wheel. A further movement of the lever to the right or left opens two valves into two additional pipes leading to the bottoms oi the cylinders. radiator. This wheei is mounted on two pistons which may be forced down in vertical cylinders by means of a fluid under pres- sure from the en- gine cylinders until it contacts with the ground. When the pistons — have moved extreme bottom positions and the. — front wheels of | the car are lifted | clear, the ends of the pipes leading to the bottom of left or right cylinder, accord- A further down- ward movement of the pistons raises the front wheels of the car clear off the ground. The operation of lift- ing and turning a car is controlled from a lever mounted in a small case in the driver’s cab. One double-ended pipe is screwed into the combus- tion chambers of two of the engine cylinders and then led to a double piston valve in the control case. This piping serves to carry a small amount of the compressed cylinder gases to the piston- valve, by the manipulation of which the oil in the two vertical cylinders carrying the small lifting wheel on their piston rods is put under pressure. Check valves are placed in the line outside of each cylinder so that the oil cannot back up into the engine on the suction strokes. The control cylinder in which the double piston valve reciprocates is normally open to the atmosphere so that the gas under pressure from the cylinders may escape when the device is not in operation. A backward movement of the control lever: shuts off the opening to the atmosphere and The small wheel carried crosswise of the car between the front of the motor and the radiator is mounted on two pistons by which the front wheels are raised With the rear wheels as an axis, the car‘can be turned completely around in a space equal to its own length ing to the way the lever is moved, come op- posite ports in the hollow piston rods and permit the oil to flow down into the pump on the wheel and turn it one way or the. other through gearing. The fluid under pressure escapes down the hollow . piston rods to the gear | pump integral with the — small wheel, so that the -. right or left. In this:way © the car is turned com-_ rd pletely round, end for end, in its own length. The car is lowered to 7 the ground in the reverse manner. Check, valve Cylinder ef ij J a} Pipe to rotary mot ; wheel ~ The lifting and turning operation is controlled from a single lever mount- ed in a small case in the driver’s cab 512. down to. their — small wheel is revolved to — Popular Science Monthly Can the Baby When You Take a Journey S Ba good news is true. We have been hoping for years that some in- telligent inventor would come along with a device to can obstreperous infantsduring the late hours of the night. We sug- gested a hermeti- cally-sealed can wrapped in sound-proof ma- terial, but Caleb M. Prather, of Evanston, I1li- nois, who is the | inventor of the can illustrated, sidestepped our instructions at several important points. He intends to use the can to rock babies tosleep. It is,in fact,a baby holder. Our can was to be a baby holder and silencer combined. Mr. Prather has provided sev- eral holes in his can through which air can reach the baby. We don’t object to the baby getting air but as long as there are holes in the can the baby’s yells will be as nerve-wracking as ever. That was our reason for the In this holder the baby sits when awake or lies when asleep on the trip 513 Will the Shell Burst When It Is Fired? A Water Test Tells PROJECTILE fired from a gun is X subjected to enormous strains which it must be strong enough to with- stand; otherwise it might be as dangerous to the gun crew as to the enemy. To assure safety as well as destruc- tiveness, the steel from which the shells are made is subjected to different tests. Not only this but further examination is customarily made on what are known as test shells. Some of these test shells are actually fired in the testing grounds; others are cut up and the pieces subjected to various strains which must be successfully resisted. Since this can’t be done to every shell, the shells used are picked at random, it being assumed that they typify the lot. The probabilities are that this would be so, but. it is better to supply a simple pressure test required for some of the French shells. This French pres- _hermetically-sealed ean. A cover of the can is fastened by a button, and a seat is» provided upon which the baby can sit and suck his thumb when the top and cover have been re- moved. Thecanis of steel and it can be fastened to the rail of a porch, the back of a chair, or the seat of a rail- road car. If the inventor will make his can air-tight and sound- proof— features which we originally suggested —we know of a bachelor who will sure test consists simply of filling each shell with water and then subjecting it to a strong water pressure for about thirty seconds. If the shells are weak, they will either burst under the strain or a_per- manent expansion will take place. On the other hand, if the shells do not collapse and no per- manent. expansion takes place, the shells must be satis- factory so far as their strength is concerned. This is conclusive evidence which can be se-'° buy a half dozen right away. Shells filled with water are subjected to a strong water pressure test for thirty seconds cured for each shell with little trouble. From Soup to Nuts “Who’s wiio” behind the scenes in a big hotel or restaurant kitchen restaurant or hotel is simple enough— to the diner. But-it is safe to say that few have any idea of what goes on behind the scenes, that is, in the kitchens, after the order has been given to the Waiter. As a matter of fact, giving one’s order of, say, oysters, soup, fish, steak, salad, dessert and. coffee starts a most intricate process. In the first place, your waiter cannot give your entire order to one cook; he must go to as many different men as there are dishes on your order.. First he stops at the oyster booth, where two or three men do nothing but open oysters. Then he goes to the soup cooks, of whom there may be six or eight; next, to the cooks who look after the fish, and so on to others who are specialists in the preparation of steaks, vegetables, salads, desserts and coffee. In the average large restaurant there are from seventy-five to one hundred and fifty cooks, all of whom, with the exception of girls who prepare the salads and vegetables, are men. In addi- tion, there are the chef and his staff of assistants, who. may number half a dozen and whose duties are to oversee the work of the others rather than to cook. When your waiter has given your full order he returns to the oyster booth, gets your blue points and takes, them to you. On his way out the oysters pass under the eyes of no less than five differ- ent checkers. While you are eating your oys- ters, the waiter goes back after your soup, which must also receive the approval of the five checkers. The same process takes place in connection with eachdish brought out, which means that your waiter, who seems so de- liberate, does 2 ees a meal at a fashionable It only takes a word to order a dish, but it takes. a whole organization to serve it. You may rave at the waiter for being slow but while he is out of your sight he is hust- ling from cook to cook with lightning speed hustling during the serving of your meal. The huge range, from forty to sixty feet long, is given over to the frying of different kinds of food. It also contains the ovens; the broilers are separate. The steward is an important personage in any large restaurant, and commands a large saiary. He must not only know what people like to eat, but he must have statistics to show about how many people will order each item on the bill of fare. The preparation of a bill, important as it is, by no means constitutes the steward’s chief difficulty. He must know at all times exactly what the pantries and refrigerators and storerooms contain, and in ordering food from the mar- considerable Checking up the food on his tray. The waiter has to pay for each item in chips out of his own pocket 514 kets, he must be Popular Science Monthly A battery of cooks surrounded by pots, pans, covers, and skillets which are all used during the busy rush _ hours At right: A special erder for a guest known to be hard toplease. Thehead chef is there to cast hiscritical eye over it ebay : sure that he has enough of every- thing to fill all probable _ orders, and yet not. so much that it will be wasted. He . doesn’t have to guess at how many people will order this or that dish so much as might be imagined. He has a book in which are pasted menus of many other days. On these There are from seventy-five to one hundred cooks in the average restaurant. All are men. But girls prepare the salads and vegetables he has’ marked the number of people that ordered a certain dish when it was offered before. Consequently he is able to judge very closely how much should be prepared the next time. If by any chance there is a larger call for the dish than on the last occasion, the steward, who watches everything going on in the kitchens, notes this, so that by the time the supply begins to run out, he is having extra orders of the dish prepared. That is why a restaurant of the better class is seldom “‘out of” anythir-~. And it is to pay the szlary of all these that your five-dollar bill goes, as well as to meet the cost of provisions. 516 Popular Science Monthly . Both desk and chair are mounted on stools. The rela- tion of the hands to the keys remains the same whether the operator stands or sits at her work Work the Typewriter Standing and Sitting—It Lessens Fatigue . HERE is no waste of any kind in the world,”’ says Frank B. Gilbreth, the motion study expert, ‘‘that equals the waste from needless, ill-directed and ineffective motions.’’ One result of this waste is fatigue. Some fatigue is necessary and some unnecessary. It is the business of the efficiency en- gineer to eliminate all unneces- sary fatigue and to distribute the necessary fatigue properly. As the result of his study of fatigue, Mr. Gilbreth has come to the conclusion that few work benches or tables are absolutely satisfactory that do not permit the worker to work equally well standing or sitting. The worker should be measured for the chair in which he spends one-half of the time that he is awake during his entire working life. If the worker can perform his task standing as well as sit- ting, his implements and his work should be so posi- tioned that he can relieve his tense muscles by dis- carding his chair. Take the two accompany- ing photographs as an ex- ample of what Mr. Gilbreth has done for the typist. Note that both the typewriter desk and the chair are mounted up- onstools. The relation of the hands to the keyboard remains the same whether the typist stands or sits. When she is tired of sitting, she has only to push aside the chair and stool and to continue her work standing. Here we have an example of the prop- er distribution of necessary fatigue so that the efficiency of the worker is in- creased and her well-being improved. Each Salesman Has His Own Tele- phone in This Grocery CHICAGO grocer increases his busi- ness through telephone orders by supplying each of his salesmen with a special telephone on a table bearing the salesman’s name. Thus he avoids the delays and confusion entailed by calling the different salesmen to the telephone. Each salesman has his own telephone and samples of the day’s “specials” before him on his desk so that there is no delay Popular Science Monthly Buttons Are Now Made as a By-Product of Beer HE spent yeast which collects in breweries and distilleries is put through a process which turns it out in the form of buttons, door- bell plates and knife handles. Formerly this left-over ma- terial was considered to be a bothersome waste; now it is utilized, every bit of it. As it is gathered from the vats the yeast is of a dirty, gray- brown color. The first op- eration is to dye it and then to work it over until it assumes the form of pow- der and can be hot-pressed into any form. In this ‘stage itiscalled “‘ernolith.”’ It may be sawed, scraped, filed, drilled, engraved, turned to an edge, and polished. The material has a particularly close and fine structure, and possesses sufficient hard- ness and elasticity for all ordinary purposes. . “This Truck Loader Will Lift One Ton Ten Inches Per Second ECHANICAL loading devices are not rare, but the one shown in the - illustration below has several novel features. It is in three parts: a supporting frame, a traveling crane and a dynamo for generat- ing the necessary electricity. The travel- ing crane comprises a motor, a clutch, a driving mechanism and a lifting winch. The hoist is carried Where the rigid teeth of a steel gear would scrape to- gether those of the gears made from cotton yield A hydraulic pressure of from six to eight thou- sand tons is required to make the fiber gears Gear Wheels Made of Cotton. Outlast Steel Gears EARS are now being made of ordinary cotton which outwear those made from the finest steel. It seems incredible, but it is true. The very hardness of the metal gears causes the teeth surfaces to scrape over each other when they mesh, producing hideous screeches and groans. Every one of these scrapings means a Cer- They on a transverse track which is part of the traveling crane, so that it can lift a load from any point across the width of the ma- chine. It can be locked in any position desired. The winch has a capacity lift of one ton at the rate of ten inches per second. E. Fourhee, of Paris, is the inventor. ing hoisting crane, which is electrically driven by a dynamo under the floor tain amount of wear. Teeth made out of compressed cotton yield. They are there- fore perfectly noise- less. Compared with the metal gears, they are indestructible. To make these fiber gears, a large cylinder built up of cotton disks is compressed to but one sixteenth of its former length! The New American Enfield Rifle A modification of the English Enfield with which our troops will be supplied N order to obtain a sufficient number of rifles with which I to arm the new United States army in as short a time as possible, the War Department has decided to supplement f its supply of Springfields with a modification of the English £3 Enfield rifle which is being manufactured in this country in large quantities for the British government. When plans for the army to be formed under the pro- visions of the draft law were being worked out, it was realized that the facilities which the Government had at hand for making the 30-caliber Springfield rifles were not adequate to turn out the number of rifles needed. and that to build factories capable of supplying this number would mean a delay of many months. Three big arms concerns were then making about 2,200 Enfield rifles a day for the British Government and they were in a position to increase even this output. Hence the decision to manufacture a modification of the English Enfield adapted to the standard 30-caliber ammunition of the United States rifle. Within a few months these concerns will be making more than 5,000 of the new rifles a day for the United States Government according to present estimates. The operating mechanism of the new rifle, while differing in general design, has the same functioning features as the Springfield; that is to say, opera- tion of magazine, loading and extracting, rotating motion of bolt and side ejection. The barrel is made of the same specifications as the Springfield with the exception that it is two inches longer than. that of the Springfield, which measures 23.79 inches. The weight of the Springfield with bayonet attached is 9.69 pounds; the new Enfield model weighs about three-quarters of a pound more. The bayonet of the new arm is 1.125 inches longer than that of the Springfield, which is 16 inches long; the assembled rifle with bayonet attached is 4.125 inches longer than the Springfield, which measures 59.212 inches from the butt plate to the point of the bayonet. The design of the bayonet of the new rifle is practically the same as that of the Springfield bayonet, the only difference being that in the new rifle the back or top edge of the blade is straight along its entire length and the front or lower edge tapers to a poiut. The magazine is practically a duplicate of the Springfield, permitting the use of the same cartridge clip carrying five cartridges. In the Springfield the rear sight is on the top of the breach end of the barrel whereas in the new Enfield it’ is on the toprear end of the receiver, _ 518 Popular Science Monthly _ That Bit of Butter Left on Your Plate —What Becomes of It? HERE are about sixty-four individual helpings of butter in a pound, each helping equaling about one fourth of an ounce. If the accumulated “scrapings” from the butter-plates after the meal were estimated there would probably be about one “pat” collected each day, in the average household. But if every one of our 20,000,000 house- holds should waste one fourth of an ounce of butter daily, it would mean 312,500 pounds a day, or 114,062,500 pounds a year. To make this butter would require the product of over half a million cows. Even if such a waste occurred in only one home out of one hundred, the waste would still average over a million pounds—which is intolerable to think of, when the value of butter is so great intrinsically and gas- tronomically, and when those bits of butter might be put to such good usage if collected in a crock by the cook. a This Vacuum Cleaner Is Used Like an | Ordinary Broom NEW vacuum cleaner which operates without electricity combines the fea- tures of a carpet-sweeper and ordinary broom with the special vacuum feature. A bellows, which is operated by the backward and forward motion of the cleaner, furnishes suction which draws the dirt and dust up into the retaining bag. Revolving brushes in the central portion of the cleaner and a row of stiff bristles around the border serve to stir up the dust and loosen its hold on the threads of the carpet. As the particles are dislodged by the bristles, “ the brushes sweep them under the 4 mouth of the suction tube and the bellows pressure sucks them up into . the vacuum. In this way every particle of dirt is removed. The work is thorough and is accomplished with little effort. The cost of the cleaner is low and the operation is as little complicated as that of the ordinary broom. Thebrushes may be used alone. | ia 43 ~—— me The . -racuum-broom, 519 which sweeps the carpet and then takes up the dirt by suction Shipping butter in crates in which an ice container is inclosed for refrigeration How Print Butter Is Shipped to the Retailer ‘HE wholesaler who sends his butter out to the retail trade in neatly wrapped pound-packages or “‘prints,’ runs less risk of having his. product spoiled in transit than if the butter were shipped in tubs. The accom- panying photograph shows how he manages to keep the butter fresh and in shape until it is delivered. Into each packing box a closely covered tin filled with ice is placed. Around this the prints of butter are packed. Then the cover of the packing box is nailed on. The cold air is thus confined inside the box. , The ice melts very slowly, so that the butter is kept firm and hard for many hours. Even when there are long delays in transit so that days instead of hours are - consumed, as sometimes , happens, the butter re- mains hard and firm; for if the ice should fin- ally melt, the water in the tin. would still re- ‘main almost ice-cold. 520 Popular Science Monthly © Newman Traveltalks and Brown and Dawson Every bit of wood in the little house has its story or legend. The images are the figureheads taken from the bows of vessels. The Graveyard of Ships that Passed in the Night ONNSANTO is the name of a man remarkable not only in character but in occupation. His home is the Island of St. Thomas, recently bought from Den- mark by the United States. A visitor to St. Thomas cannot fail to hear about him, and should not miss the opportunity of seeing him. He lives on Krum Bay, a crooked arm of the blue Caribbean, almost landlocked by the hills that surround it on three sides. It has been the graveyard of many a ship. In this little haven the vessels were disman- tled; the shore-line is strewn with their re- mains. The home of Monnsanto is con- structed entirely from the wood of these ships. Every beam and plank has its story or legend. Wood is wood and iron may be iron, but when it is put into the form of ships, it becomes a thing of life andjeach plank shares the ship’s history. filled with The cells of this pencil-pen are ink which ated as the wax They are very lifelike and peer uncannily from unexpected places What Is It—Pencil or Pen? It Has Neither Wood nor Graphite WRITING implement composed of a mixture of wax and finely-ground pumice stone containing particles of ink, has been invented by William C. Geer, of Akron, Ohio, to take the place of ordinary and fountain pens, pencils, crayons and all other writing implements. As the body. of the new writing device is composed of a mixture of wax and pumice stone, which is easily worn.away when rubbed against a paper surface, the inventor claims that the cells of ink intermixed with the wax and pumice stone will also be liberated, giving a uniform-supply of ink. The device is made by mixing the wax, pumice stone and ink together. When it is heated to the proper temperature it is sud- denly immersed in cold water. This chills and solidifies the wax mix- ture, producing a body having a cellular structure, each cell being filled with ink. 7 is liber- interior melts Popular Science Monthly 521 _A Shock Absorber for the. Soldier’s Kit OT all the difficulty that a soldier has in carry- ing a pack on his back is due to the sheer weight of it. An equal, if not a greater strain is caused by the con- stant jolting of the equip- ment as he walks along. To ease this strain, ¢an . Englishman, James A. Pugh, of Cardiff, Wales, has in- vented a pneumatic shock absorber for the soldier. The incessant jolts of the soldier’s pack are cushioned on this, and the strain of marching is correspondingly lessened. Two small pads of rubber are sewed in pockets at the shoulders of the man’s tunic. Another similar, but larger pad is sewed in the back of the tunic, just above the belt. Corrugations on the under side of these pads allow the circulation of cool air, so that the soldier’s back will not feel the heat of the pack. By. inflating all three pads through the small connecting tubes and their check-valves, they are converted into veritable cushions which will take away all the shock of the heaviest pack. The pack is fastened on in the usual manner, and is then inflated through the mouthpiece shown in the photograph below. The two ends of the mouthpiece fasten together across the front when not in use. When unclasped, the pads be- come deflated automatically. \ Ca A Mouthpiece 4 Wintistea? r~ % pad # BR ah Sees we ae ‘Tube! {edeeecee “79 as PRES 2 eines 2 RLS © Newman Traveltalks and Brown and Dawson A life-boat drill on board a coast liner. board must don life-preservers when a bell rings These air-filled cushions keep the back cool and protect it from jolts All on The Life-Preserver Is More Important Than Meals Aboard Ship HE life-preserver is your best friend when you travel on ocean liners these days. Even the captains of ships that steam along the coast insist that you get: acquainted with the life-preserver the first hour or so you are on board. Lifeboat drills are now regularly held on all liners. At the sound of a bell the passengers and as many of the crew as can get away from their posts, rush to positions on deck previously assigned to them. They immediately don their life-preservers and then wait for the next signal, which may direct them to get into the boats or order them back to their staterooms. A certain number of pas- sengers are assigned to each boat and an officer is appointed to take charge. Sometimes drills are held every two hours dur- ing the day to acquaint the passengers thoroughly with their positions on deck and to get them used to the warning bell which usually sounds when least expected. The life-pre- servers are made. of canvas-covered cork. 522 Two Ties in One—The Bow and the Four-in-Hand . D. BAILEY, of Coffeyville, Kansas, has devised a method of saving his ties by combining his four-in-hands and bow ties in one tie. Thus he can wear the bow ties as four-in-hands, or the other way around. His first efforts resulted in a folding tie, too bulky to be practi- cal. Then he put one tie inside the other, making one serve as the padding of the other. That met all requirements. This method of combin- ing the ties by means of clasps eliminates all padding in the four- in-hand, because the bow tie takes the place of the pad- ding, and also elimi- nates all but the end of the four-in- hand itself. In the duo-tie there is little more material than in the regular four -in- hand. The under part of the tie does not show when worn, so that you could wear a green bow tie and a red end, if you wanted it that way or any other combination. Tying a four:in-hand. When worn in this way the bow-tie portion is the padding Your Motor Is Known by the Piston Rings It Has : OW far and how fast your automobile travels, depends upon the power emanating from the motor, and that power, in turn, depends upon the piston rings. Piston rings are inserted because they increase the motor power of the car, keep the compression at maximum and therefore put more power behind the drive of the piston itself. A good piston Popular Science Monthly power. Therefore, the piston rings are the soul of an automobile motor. The finest built motor with indifferent piston rings is an indifferent motor. Built to give a rated power, it loses that power if the piston rings do not conserve it. When you select a piston ring for a motor, it is best to get a ring that is made of one piece. Since the piston of a gasoline engine has to work in its cylinder millions of times, the fewer parts there are the better. As a rule, the piston ring should be made of durable cast iron or steel. It Holds and Presses Your Tie at the Same Time COMBINED necktie holder and press which takes the wrinkles out of your scarfs after you have worn them is the latest con- venience for the man who is particular about his-neckwear. The holder and press is of veneered maple. It takes the wrinkles out of a scarf at the particular place where they have been caused, by stretch- ing that portion under spring wire clamps. The wide part of the tie is held in a press as well as the narrow part, strong wire springs holding the wooden members closely together. The holder may be hung on the wall, as a portion of the -wire spring projects for, that purpose. Several ties can be accommodated in the holder at one time. fie ee Pressed in this way, the ties are kept smooth without the sheen imparted by a hot iron. ring will touch the cylinder walls at all points, making an air-tight joint. With all joints air-tight the gasoline concentrates its entire energy on the top of the piston head when it explodes.’ It is like the charge of powder behind a bullet in a rifle. eet A poor piston ring, like an ill-fitting bullet, will lose much of its propulsive A holder that keeps your ties in shape by pressing them tightly between boards clarmoed together Popular Science Monthly 523 A Crutch Built on the Principle of the Rocking Chair NEW crutch has sulate the water from the heat of the fires. A method employed by a Chicago firm for doing away with the soot evil, first allows the soot to col- made its appear- ance in England, where crutches just now are as numerous as walking sticks. Its principal feature is a rocker at the base, like that of a rocking chair. Thisis said to make walking easier. Instead of two sticks coming together to form a round stump the sticks of the new crutch are continued parallel from the shoul- der-rest to the rocker. . The rest that fits under the armpit is a curved piece of: hollow rubber tubing, like a motor-car tire, and the lect. Then, through rows of nozzles mounted at short in- tervals at the top of the water tubes, live steam is passed at high velocity. At first, the steam jets are directed downward on the lower rows of tubes. No speck of dust can. hold its perch. By slowly rotating the nozzles, the turning jet is di- rected upon the middle rows of tubes, and lastly upon the very top ones. The battery of steam jets strike at an angle. The steam glances off, carrying handle is adjustable to the height. chair, Steam Jets Which Save Thousands of Dollars in Large Power Plants N large power plants even little ‘“‘losses,”’ if allowed to continue, will produce an annual loss of thousands of dollars. Of all such losses, that caused by soot is one of the most persistent. Collecting as it does in layers perhaps an inch thick about the water tubes in the boilers, it serves to in- The crutch has a rocker like a rocking which makes walking easier the soot with it with- out wearing away the pipes. At no point do the nozzles direct the steam directly upon the pipes. By blow- ing diagonally-upon them the force ex- erted is used in carrying away the soot rather than in beating upon the pipes. In this. way a boiler can be rendered one hundred per cent more efficient. Less coal or fuel will be required to get up a given amount of steam and the pipes and metal parts of the boiler will last longer. trate steam on next tubes Ai gher up. fig 2-B Side eleva- tion of a tig 2-A fLlement onal plane rotated 45: Showing pow Nozz/es steary fers Shightly otf blowing en the diag- Center Conce: ona/ are deflected along tube surfaces producing thorough chaning. Layers of soot on the water tubes of a boiler insulate the heat from the fires. Such a condition is avoided by blowing the soot off with high-velocity steam through sets of rotating nozzles 524 Nasty Job This—Cleaning Customers’ Ears VIDENTLY the Japanese are a long- suffering people. Take for instance the docility of the Popular Science Monthly the handles the swing is set in motion. The harder one pulls the higher the swing goes. The inventor also provides the swing with foot ropes which may be operated in conjunction with the hand ropes or in- dependently of occupant of the barber’s chair in the accompanying photograph. He has. seated himself there to get his hair trimmed and. will pay the price, no doubt. But as part of the tonsorial op- eration, the barber, with a contrivance somewhat like a series of blunt knit- ting needles padded on the ends with cotton, proceeds to clean out the ears of his patron. The boy in the back ground _ illustrates them. These are fastened to the handles in the same . manner as the hand ropes. By working both foot and hand ropes the swing can be set in motion almost immediately. By pulling downward the swing is forced forward, and when the handles are re- leased the weight of the child forces the swing backward. The foot-ropes and stirrups also make it possible for two children to the oriental’s fear of the camera. Pulling and Pushing to Make the Swing Go ECAUSE it was impossible to read the’ evening newspaper and swing his children at the same time, George A. Netcott, of Independence, fowar® set about to devise a self-operated . swing which would enable a child to swing itself without calling on the parent for assistance. After developing three styles of swings he finally adopted h Pulling straps’ ry ~ M | the one illustrated on account Pet a of the ease of operation. Propelling His swing differs from the ordinary swing in that it has oy an additional pair of ropes as. which serve as the propelling 4& ¥ force. These ropes are se- cured at their upper ends to hooks placed a few inches in front of the hooks which hold the swing ropes. At their lower ends the ropes termina‘? tn a pair of handles. which slide freely up and down the swing ropes. By pulling on 4— ropes —> Cleaning out the patron’s ears is an im- portant part of the barber’s duty in Japan swing together, one operating the handles and _ the other standing in the stirrups and “pumping” in time with the hand move- ment. Although designed for the smaller children, the swing is strong enough for a child of any size. power depends not so much on the ropes as on the strength of the ceiling hooks. Its weight-carrying Hand and foot ropes connected with a pair of hollow handles enable the cuil1 to operate the swing without assistance Popular Science M onthly This Bird’s Nest Is Evidently a Two-Room Apartment IRDS, like persons, sometimes do strange things. Here is a double nest of a “Chipping”? sparrow, an un-~- usual type indeed for this bird. A guess at the ex- planation would be that a roving bird, probably a cuckoo, which is notoriously lazy and homeless, deposited an egg in the sparrow’s nest while she was taking a bit of recrea- tion. When the spar- -yows discovered it they busied themselves making an addition to the ‘original nest, to which they transferred their own eggs, leaving the intruder’s in the old nest to addle. Which Is It—Boat or Motor Car? It Travels on Both Land and Water roll; slipped over a ‘ » pin-in the hinged . cover, is. -fed . for- ward by a system of levers:operated by ropes all along the Way. capacity of two thousand let- This machine differs from others of its kind in that it moistens the envel- ters per hour. ope instead of the stamp and in this way does away with the possibility of the stamps gumming and thereby preventing the successful operation of the machine. The machine is built up Bring back springs © Brown and Dawson A slow-burning rope twisted from waste is the “‘lighter’ of the Stamping Two Thousand Letters an Hour with a New Machine ONE would be the stamp-licker and the wet sponge were every office furnished with this new mechanical stamper having a envelope. Italian cigar keeper the downward push of the handle. Thus the strip of stamps is automatically fed out to a point beneath the base of the handle-plunger and auto- matically cut off at: the proper perforation just when it is affixed to the moistened The system of levers is brought back to its original position at each release of the handle by means of several The corner of the envelope is mois- tened with water fed from a tank through a wick, ending just above the envelope plat- . form at the right of the plunger base. Then the handle presses the stampon small springs. A small rod attached to one of the levers of the system is made to move back and forth at each depression of the handle and to operate a register with a dial on the front of the machine which dial indicates the number of stamps used. The stamp device may also be locked, so that no stamps can be removed. By means of the register, an accurate count of the number of stamps can be kept for any given time. To affix a stamp the corner of the envelope is shoved under a moistened wick. Thehandleis pressed down and then springs back automatically. 538 Popular Science Monthly A Houseboat of Marble Built to Amuse The Airplane to the Rescue of Storm- Chinese Royalty Tossed Mariners! HE most ORE beauti- than a ful and per- hurricane on haps the the high seas most costly houseboat in the world is the one illus- trated on this page. It is made entire- ly of. marble and served to amuse the household of Chinese ‘do sailors fear even sixty-mile gales near a rocky coast. To the life savers, also, a rocky coast Gs iost dan- gerous. In. - any attempt | | Of theirs to royalty. ‘reach a ves- When the The marble houseboat is exquisitely carved and has elab- sel that is boat’ was orate trimmings of solid gold. It ‘is enormous in size. . doo m e d;, built no one what -is to knows. It floated on a small lake within the precincts of the “Forbidden City”’ in the last days of the Manchu dynasty.. Re: cently it was removed to the national park in Pekin. “Do It Electrically’? Also Applies to the Up-to-Date Barber N electrically operated hair cutter which entirely. eliminates the shears has been devised. It con- sists essentially of a light standard with ‘cross-arms’ at the top to support a small electric motor connected with the clippers by a flexible cord three or four feet long. In cutting long hair the fingers and comb are used in exactly the same manner as with shears. In out- lining the hair in front the cutters are turned up- — side down and the points pressed close to the skin; this produces a straight line without danger of cutting the skin. When the cutter is held in the same position and passed rapidly over the hair stray wisps are removed. The hair is cut in a fraction of the time us- ually required. Cutting the hair electrically with clippers instead of shears keep their puny shell from being dashed upon the rocks? During the great storms off the coast of ‘Maine, for instance, the experienced guards well know the useless- ness of any attempt of reaching ships in rowboats. Rockets or cannons are brought into action immediately and with these the guards - Abc as to shoot lifelines out to the -foundering “vessel. ree With these lines, it is - em, often possible to carry » the sailors off the vessel ‘in hawsers. Notwith- ' standing this admirable method, there are times when the lines ‘do not reach thesinking ship and crew. Rocket nor mortar is powerful enough to carry the heavy lines against the wind, far off the land. But shall we let the sailors perish, because of that? Not while there is a way - out. And that way is with the airplane, the next great servant of man that is coming as soon as the world sees a righteous peace. The airplane is a rider of winds, and sixty-mile gales will. never prevent it from carry- ing a lifeline to the ship! The plan has already been worked out by the United States Coast Guard. Throwing Out the Lifeline by Airplane <2 ———————$— a ? ee <2 +. ¢: <2 (2 *, ee eS | . | K | , + | Sailors ona schooner fear nothing so much as a storm off a rocky coast. Once the wind carries them against a rock, the ship is lost! It is useless for the life guards to attempt i to reach them; their only hope lies in a rocket or mortar which can shoot a lifeline to them. When these fail, the only hope of getting a line to the seamen, is with.the airplane Hi ga 4 2S a A ge gene 5 x ZS 5 3 540 The Bomb-Droppers Are Coming! Hug the Ground HIS is the advice which is being given to the school children of Sussex, England. dropping suddenly face downward and re- maining perfectly They are being drilled daily in . - Popular Science Monthly Torpedoed! But the Cargo Floats Off Safely [Le question of saving the cargo of food-stuffs on a torpedoed. ship has received what seems to be a practical answer by W. G. Durant, of Jacksonville, Florida, who pro- motionless on the ground, just as our school chil- dren are put through the fire drill. The reason for the ground- hugging is not quite clear to us, unless it is to make the. street appear deserted to.the bomb- throwers in the air. tees Heretofore the people of. Eng- land have been so careless in re- gard. to their. be- havior during an air raid that they have played into: the hands of the raiders, so to speak, by flock- ing to the roofs of their - houses and swarming the streets in order to get a poses to seal up the cargo in gal- vanized iron con- tainers which will float on the sur- face of the sea after the _ ship has sunk. His idea is not unlike that of Menotte Nanni, which was described in the March issue of _ the PopuLak Sci- ENCE MONTHLY. Mr. Durant plans to make his air-tight con- tainers large enough . to -hold cargo weighing from two to fifteen tons. Each tank is to contain a com- pressed air cham- ber to-afford the necessary buoy- ancy, and each is . to be equipped with a hook and good view of them. This led to an official edict requiring all persons to get into and keep inside their houses or any available house when a bomb-dropper was reported in sight. If Your Eyes Are Weak Use a Less Brilliant Desk Light F you have a sense of faulty vision it is a natural inclination to seek ‘a very strong light by which to read or study. This simply adds to the eye strain. The best light is an indirect, diffused light of sufficient strength to make the letters on the page stand out in uniform distinctness. Avoid the brilliant reflection from metallic objects that may be on the desk. School children of Sussex, England, in a ground- hugging drill to be practised during an air raid chain, so that a large number of containers upon floating to the surface can be fastened to- gether and towed to land. The crew of the torpedoed vessel could use the floating containers as life rafts. So far as the destruction of the containers goes, it would not be practicable for a submarine to waste torpedoes on them. Of course a submarine could shell as many containers as it wished, but this would not continue for long with so many vessels patroling the barred zone. A feature of Mr. Durant’s plan which is more important than the containers themselves, is the ship which will carry them. The inventor does not favor the ordinary design of ship, but he suggests a ship without decks to enable the con- Popular Science Monthly The food cargo is carried in air-tight, water-tight containers which float on the water when the ship goes down. Each tank contains a compressed-air chamber to provide buoyancy tainers to rise to the surface and with the engines and boilers located in the center and: the cargo containers fore and aft. A ship so built that the containers could be placed in the hold, with the decks merely pinned over them, is also con- sidered. With such a ship the containers could easily force the decks upward when the inrushing water caused them to rise, and come to the surtace. They could float about on the water for days if neces- sary until salvaged. . Popular Science Monthly — ‘© Underwood and. Underwood: . A_ demonstration of what happens to an airplane wing which has not been coated with the fire-proofing liquid when’ a spark of fire comes in contact with it Protecting the Airplane with a Fire-Proof ‘Coating NEW varnish or coating for airplane surfaces which makes them. fire- proof has been introduced by W. R. Weeks, of New York city, who is . interested in the treatment and waterproofing of fabrics. Of late there have been a num- ber of so-called fire-proof paints and varnishes pro- posed for the airplane. Without exception they have proved worthless when sub- mitted to a rigid test. Furthermore, they have caused delay in turning out ma- chines, because a number of coats of the fire-proof paint had to be applied one coat after another after the usual paint- ing of the airplane was completed. The new coating manufactured by Mr. Weeks is conceded to have several advan- Twelve of the forty-three bombs found in a freight car loaded with scrap material for a Chicago foundry; and the man who discovered them damage. tages over others. In the first place, it can be applied by machine as well as by hand, and it requires much less: time in drying than any other liquid of a similar character at present on the market. But in this_as in other paints for the pur- pose, from six to ten coats are required to make an airplane proof against fire. The accompanying illus- tration shows what happens to the ordinary airplane wing uncoated with the . fire-proofing liquid, when a spark ignites it. For the . protection of aviators ‘in air battles it is necessary that such hazards be mini- mized. wing, if it caught fire, would burn so slowly that the aviator would have a chance to descend. ‘Forty-Three Bombs in a Freight Car Load of Scrap Iron ORTY-THREE bombs freight car loaded with scrap iron bound for the furnaces of a big foundry in Chicago, were discovered by the keen eyes of Government agents recently. The discovery was made through the watch- hidden in a fulness of George Mar- mann, the man shown in the photograph, who became suspicious when he noticed the round objects mixed with the scrap ma- terial. He told his superiors of the fact and they, in turn, communicated with the Department of Justice. A. subse- quent examination of the bombs brought out the fact that there was enough explosive matter in each of them to blow up a half dozen foundries and do_ incalculable A fire-proofed — Popular Science Monthly The Rising Price of Auto- mobiles—Charge It to the War HE policy of automobile manufacturers of yearly reducing the price of their cars has received a severe jolt. With steel, copper and rubber going out of the country as they have, the rising cost of these materials promises to sweep the price of the cars up with them. Steel for forgings has gone up nearly three hundred per cent since the beginning of the war. Aluminum quota- tions are trebling those of two years ago. Leather, copper and other finishing ° materials have advanced from twenty-five to one hun- dred per cent. Even the cost of the labor, the largest single item in the manufac- ture of a-motor. car,’ is con-— siderably greater than it ever rated ee ay Sei ea i eee noms mmm was before. The framework into which the concrete is poured is a part of the permanent structure and hence need not be removed The Overdriven Nail and the High . Cost of Living nye wooden packing case is required with every twenty-four of the billions of cans that America uses in her canning industry each year. The expense of the cases, when everything is added up, is so great that packers are availing themselves of every invention or idea which promises to reduce it. One of the facts they have found out is the economy of properly adjusting the automatic case-nailing machines. When the strokes of these machines are even a fraction of an inch too Jong, the wood fibers are cut and the havoc is wrought which the ac- companying enlarged photograph well illus- trates. It seems a more economical plan to pay a workman to adjust the machine than to stand the expense of repairs. The havoc wrought by an overdriven nail in the fibers of a packing case A Substitute for Forms in Concrete Roofs and Floors Bene necessity of erecting temporary wooden forms for concrete roofs and floors is avoided by the use of a metal sup- port which becomes a part of the permanent structure and which not only takes the place of reenforcing material but also helps carry the load. When the framework has been put up, large sheets of the metal work are laid over the supports and fastened; then the concrete is poured, the under side cement) plas- tered, and the job is complete. Less time is required than with the ordinary forms. In addition there is less expense for labor and material, and the concrete work may be made lighter. The metal material may also be used for concrete work in other construction than that of roofs and floors. , 544 An Iron Worker’s Steel Glove. As Flexible As Leather GLOVE which will give as much pro- tection to a man’s hands as a glove of ,rigid steel, yet which is as flexible as any glove of leather, has been de- veloped by a Western manufac- turer. It is not the quality of- the steel which ‘is responsible for these properties; but it is the clever way the ribbon steel is interwoven in the leather. The steel rib- bons are woven across the width of the glove so that the fingers can be It Is flexed in them _ with perfect ease. The ribbons _ being close woven, they afford foundrymen and me- chanics a perfect protec- tion from the sharp and ‘ragged edges of iron pieces. Moreover, by bringing the stitches of the ribbons to the surface at every wear- ing point, the glove, rather than the hard, gets the rough usage. The steel stitches thus also protect the leather, so that the gloves will: last indefinitely. Such a:glove will be found a boon in such work as sand blasting, in iron turning, iron grinding and chipping, and even in weod working. The “Red Cross” for the Soldiers; the ‘“‘Red Star’’ for Their Steeds ITH the advent of the United States into the war, the American Red Star Animal Relief Association springs into prominence. It is an organization which does for the horses what the Red Cross does for the soldiers. The association has branches in most of the European countries and its work is authorized by the Secretary of War. Its main objects are to found veterinary hospitals and furnish veterinary attention and supplies. wherever needed. It is pointed out by the organizers that the care and conservation of the animals used by the army is an important patriotic duty and will contribute directly to the success of the army operations. Popular Science Monthly Steel ribbons are woven across the width of the glove Inspecting the Six-Mile Gunnison Tunnel by Automobile OME time ago we printed an account of the inspection of a sewer by motorcycle. Now comes a description of a trip through the Gunnison tunnel by automobile. The trip was made by Fred D. Pyle, of the United States Reclamation Engineers, and its object was to inspect the work on the automatic gages in the tunnel. Ordi- narily this work takes up an entire day, and entails a long hike with ladders and blue-prints galore. In the automobile all the tediousness of the trip was eliminated. into the tunnel, and although the weather was sloppy the trip was made in sixty-five minutes trouble due to splashing water and dampness. It demonstrated the practi- cability of using the auto- mobile for inspection work and for transportation of supplies to gate tenders. The machine was turned without leay- ing the tunnel, so that a twelve-mile run = was made under the mountain. This automobile made a twelve-mile inspec- tion round trip through the Gunnison Tunnel and back in sloppy weather without mishap =e The car was lowered | notwithstanding engine. - ' willing to answer questions. Air Scouts Learn to Sketch Battlefields Instruction in making drawings which will show accu- rately the enemy’s positions, is given to every air scout ‘lines of trenches, © Underwood and Underwood A class of airplane observers making sketches of an enemy’s battlefield of sand and sticks. Each man imagines himself to be flying a thousand feet above the battlefield in an airplane MAGINE yourself flying in an airplane _a thousand feet over a battlefield, with instructions to make a drawing of what you see. You have but a minute or two to make your drawing, yet you must sketch in the enemy’s gun positions, his his transport roads, and all details of military significance. Your sketch must be accurate, otherwise your batteries would waste valuable am- munition in shelling the enemy’s positions and perhaps the plans for an entire offensive would be upset. That, in brief, is one of the important duties of an airplane scout. _To do this work faithfully and accurately the airplane observer must undergo a course.of theoreti- cal and practical study. Before he takes his first flight he must be able to make sketches of “improvised battlefields, one of which is shown in the accompanying illustration. The men in the picture are’ grouped about a make-believe battlefield of sand and , sticks. Each man, in making his Sketch, imagines himself to be a thousand feet or more in the air. His camp stool is his airplane and his pad his sketch sheet. If he fails to make an accurate sketch of the field below him, he is considered to be deficient in his ability to observe. It is seldom that he has a second chance to sketch the same field, for the sand and sticks are changed continually. Those of us interested in science, engineering, invention form a kind of guild. We should help one another. The editor of The POPULAR SCIENCE MONTHLY is 45 Our First Scouting Dirigibles We have copied the British ‘‘Blimps.”’ Here the construction is explained \ , 7YHEN German submarines began to render even the high seas danger- ous to shipping, England found herself in a very perilous position. To patrol the waters around England by small craft was the immediate remedy adopted. But the area to be covered was so vast that literally thousands of vessels would have been required. Air- planes were out of the question because they lacked the necessary endurance and because of the demands made on the pilot. It was clear that airships might answer, but England had only very small ones, slow Ballonet arr suspension Air filled ballonet The gas envelope is much like that of other non- rigid dirigibles. As the vessel rises the gas expands and some of it escapes through a safety valve to prevent bursting. To preserve the shape when the gas contracts, ballonets are used, one in front and one in the rear, as explained on next page The The gasbag is 160 feet long and 31% feet in diameter, with a capacity of 77,000 cubic feet of gas. There is a.standard. 100-HP motor. provided. with. duplicate controls so that the two passengers can run the. ship alternately. Wheels are not needed under the car or Forty-Five-Mile-An-Hour “Blimp”? Which Was Considered a_ Makeshift flying and very unhandy for the purpose. Some unknown. genius hit upon the “Blimp” as a solution of the problem. England was building airplane bodies, or fuselages, as they are called, by the thou- sands—building them as we build auto- mobiles in this country. She was also producing hundreds of gas envelopes. Why not suspend an airplane fuselage from a gasbag? The question was brilliantly answered by the “Blimp.” Envelope inflated with hydrogen gas y Rip Cord in the fuselage. Even with more load than the gas can lift the vessel can be made to rise easily without a pre- liminary run on the ground, simply by pointing the nose up (through air trimming) and letting the propeller exert an upward thrust. The chief difficulty with all 546 Popular Science Monthly So little trouble was taken to adapt the airplane fuselage to the gas envelope that not even a motor-driven blower was pro- vided for the airbag in the first Blimps. Part of the airplane propeller’s slipstream, caught in a hose, sufficed. The hybrid ‘‘Blimp’”’ has shown itself incredibly superior to anything in its own class. It has a speed of forty-five miles an hour and a radius of action of several hundred miles. Its lift control approaches the seventy-mile-an-hour Zeppelin’s, be- cause the “Blimp’s’”’ surface is relatively greater, compared with its weight, than a Zeppelin’s. Moreover, for the same speed the dirigible with a greater relative surface has more grip on the air in rising or descending by reason of the airplane effect of its gasbag than if it had a surface smaller in proportion to its weight. 7 Pressure relief valve a Ballonet dirigibles is the erratic changing of the lifting force of the hydrogen gas with which ‘they are inflated.» When- ever the sun disappears, the gas cools and shrinks. When the vessel enters a cold stratum of air the gas shrinks, to expand again upon reaching a warmer Water trimming. tanks” Pie 3 sce aes ee Beginning Has Proved a Brilliant Invention And a Real Innovation in Dirigibles 547 The United States has also built “Blimps.”” The main original features of the American ‘‘Blimps’’ is the addition of a blower driven by a cycle-motor and of a second airbag or ballonet with valves to shift the air at will from bag to bag. As a result, the ship can be ‘‘trimmed”’ (that is, its flotation forward and aft can be varied at will by driving the gas where there is less air) even while it is at rest and the elevator or vertical rudder is powerless. The blast of the propeller will probably be used to inflate the ballonets, that being safer than a separate motor. There has been added an efficient device for anchoring the vessel safely in a storm. The equivalent of life belts, in the form of kapok buoys are fastened above the airplane’s floats. Hence the entire craft can rest lightly on the water, supported. by its gas. Enough water and sand ballast are carried to permit the craft to rise the better part of a mile; the safe altitude is - given as one 114. ‘miles, but with the help of the powerful airplane action of the craft itself this may be doubled. ae Be At ad A ballonet is simply an air-bag within the main balloon. When the dirigible descends and the gas contracts the airbag is blown up with air by a little motor in the car below. Thus what buoyant gas remains is compressed; and made _ to restore the envelope to its normal shape PS Soe art ja } * me) sh: oe layer. But even the old slow dirigibles could add or subtract ‘much weight.to or from their lift by reason of: their airplane action... As. this» action increases proportionately with the square of the speed the fast dirigible of today compensates easily for such variations 548 Potted Plants as a Part of a Plumber’s Equipment T often happens that plumbers are com- pelled to tear up sidewalks and streets, and otherwise muss things up in making repairs or pipe Popular Science Monthly trucks between that city and Boston, Mass., a round trip distance of 1,540 miles. The truck runs on a regular railroad schedule, carrying completed tires from Akron and taking back cotton tire fabric from the company’s cotton mills in Connecticut. Three round connections. Usually they are little concerned about the ap- pearance of the street during the repairing process. But R. H. Slay- ton, of Los Ange- les, California, is an artist at heart although a plumbing con- tractor by trade. When he is com- trips have just been completed, the last in seven and one-half days. The truck used is a regular five-ton model. It is equipped with a special body having a closed-in driver’s cab with a sleep- ing compartment directly behind it © and __ extending pelled to tear up’ a street he puts.a barricade of growing plants around the spot. This not only serves to shut off the sight of the piled- up dirt but diverts traffic. the .other way. Delivering Tires by Motor-Truck from Akron to Boston NEW era in vehicular transportation has been inaugurated by one of the large tire companies of Akron, Ohio, which is now running a line of five-ton motor- These potted plants say with a graceful nod: Repairs are in progress here’’ clear across the frame from one side to the other. This is used for sleeping quarters by the two drivers, who work in relays. It might be supposed that sleeping on a motor truck would be difficult and very un- comfortable, but the giant pneumatic tires provide a wonderful cushioning effect that makes the truck ride almost as comfortably as a passenger car. The truck load is carried in a stake body aft of the cab and is . covered with canvas to protect the goods i in inclement weather. “Go ; t toa ‘One of the five-ton motor-trucks: now running regularly between Akron, Ohio, and’Boston, Mass.s, carrying completed tires from Akron and taking back cotton tire fabrics from the company’s mills — _ Advertising By Traveling curtains, like moving pictures, attract the attention of the passerby to the continuous story FRHE very latest mode of advertising is a glass-sided and ended motor truck from which are flashed at fifteen-second intervals the advertisements of ten well- known products. The fleet of trucks run over the most crowded of New York streets from noon to midnight, each carrying its advertising mes- sage to the thousands of pedestrians instead of mak- ing them travel to the signs. Not only this, but the truck advertisements are almost at the level of the pedes- trian’s eyes. It is unneces- sary to twist your neck into a serpentine knot to gaze heaven- ward at the latest forms of sky signs. The truck advertisements are painted on transparent curtains which are hung within the body and which show through the glass sides by day as well as by night, for after dark they are’ illuminated by means of banks, or trays, of lights. Each curtain appears first on one side, then at the rear end and finally on the other side, the change from one advertisement to another being made when the interior illumination is automatically shut off tem- porarily. The appearance and disappear- —~fiesit . = Motor- Truck ua ’ over and over again. erm gees Tad ot oe eS Bi aie ee he FE = oe Plan of the Advertising Motor-Truck Ten transparent curtains are arranged on guide rollers so that three are con- tinually in viéw, one on each’ of the two sides and oneontheend. The: :; curtains are hung from a continuous steel cable which is made totravelover | the grooved guides by means of a motor driven by current taken froma’! - storage battery inside the truck body. matically so that each is even with the glass during the fifteen-second ‘stopping period while the truck is in motion. current for operating the curtain motor’ is continually being recharged through a special-charging generatordriven off the regular vehicle éngine: :: The curtains, are stopped auto-. +, The .storage battery , furnishing ,the:-: ance of the curtains are intended to arouse the curiosity and incite the interest of the pedestrian or vehicle passenger as to the nature of the next one to appear. — The arrangement of the curtains is such that the advertisement which is shown on one side of the truck body is ‘carried immediately to the back and. later on to the other side, so that although the person on the street sees'a constantly changing surface, the same pictures serve The curtains are hung on a continuous steel cable which is made to travel over the grooved guides ‘ by means of .a motor driven by ape Curtain current taken from a storage bat- cectre Wensporent guide ro =f a tery carried inside the truck body. lights curtains) Plate glass, \ pees. seat Le hope This electric motor operates a scott vertical shaft by means of a ot system of gearing. © The. stop- ae ping period-of each curtain and | . Storage Tits db the moving time, when it is aF battery 4 : replaced by the one immediately ) Gearing following, depend upon the auto-. ; matic action of a special cam device. The storage battery which furnishes the current for ‘the motor operating the curtain is continually recharged from a special charging generator driven off the regular vehicle engine. At night especially the illum- inated truck attracts attention. itiK— Worm gear and cam Diagram of the Mechanism .. The arrows indicate the direction of the curtains. each of which ap- pears first on -one side and ‘then on the opposite side in rapid suc- cession. The curtains are actuated by an electric motor which drives i a vertical shaft by means of a system of gearing. The stopping period of each curtain and the moving time when each is replaced y the one following after is governed by a ‘special ‘cam device Wires from storage battery «549 Photographing the Jolts of an Automobile How you can tell what shock- absorber is most efficient One of the Many Records Obtained The. two top lines are made by the lights worn by the passengers and show the jolts to which those in the front and rear seats were subjected; the Jower four lines’ show the movement of the car when overriding VERY one of the hundred odd manu- facturers of shock absorbers, tires, and springs claims that the applica- tion of his particular device to the auto- mobile will give the greatest possible ease of riding. Now comes Mr. W. C. Keys, an experimental engineer, with a method of visibly recording the effect of jolts on a car and of ascertaining to what extent shocks are absorbed. Electric lights are mounted on the front and rear hubs, the front and rear fenders and on. the passengers. The lights are turned on, and the car is driven at night across the field of a,camera. The record obtained shows Jecupately the “path of travel of every critical part.of the an obstruction. It is evident that the passenger in the rear seat is thrown up and down more violently than the passenger in the front seat, and that the passengers are tossed up more than the car itself car as well as of the passengers. Study the photographic record which appears on this page. The two top lines are made by the lights worn by the passengers, the topmost line representing the passenger in the rear seat and the one immediately below it rep- resenting the passenger in the front seat. The other lines are made by lights fastened on the car. Bint The four lower and straighter lines rep- resent the riding qualities of the springs and tires. The two top lines sum up the riding qualities of the car and show the effect of the. passengers’ position in relation to the axles, of the trimming of the seat cushions, of-the flexibility of the frame, etc., in addi- tion to the effect of the tires and of the The Disposition of the Lights Lights were attached to the car on the hubs,'on the fenders, on the body, and on the passengers as here shown. Beneath the car appears the obstruction which the car had to override in making the ee: 550 Popular Science Monthly springs. It is evident that the passengers are tossed up and down for greater dis- tances than the car itself when an obstruc- tion is overridden. The records seem to show that on the whole the passenger in the rear seat is better off than’ the man in the front seat. The man in front gets two jolts for each bump, first when the front wheels pass over the obstruction, and second, when the rear. wheels pass over it. On the other hand, it is evident that the passenger in the rear seat; represented by the top line, is jolted once only by the ob- struction, the wave in the line showing the spring action. It is clear that the passenger in the rear ‘seat is thrown up appreciably higher than the passenger in the front seat. At last it becomes possible to analyze exactly the performances of different auto- mobiles, or of the same automobile, with variations in such accessories as the leaf- springs, cushion-springs, inflation pressure of the tires, shock absorbers, stiffness of the frame, weight of the axles, etc. So that the unproved statements of the manufac- turers need no longer be all that accom- pany such appliances. The skull is made of paper and was used by Army Medical Students for anatomical study The Army Medical Museum’s Giant Skull OMPARED with the man standing be- side it, the huge skull shown in the accompanying photograph would appear to have belonged to a person about’ thirty feet high and to be reminiscent of the times when What’s. This? A -Mosque?. No, Just a Flag- man’s Shelter FLAGMAN’S shelter house, made up of old loco- motive parts, guards a street crossing on the Southern Pa- cific at San José, Cal. . The shelter was constructed by the consulting engi- neer from old engine wheels, springs, tires and other parts of discarded locomo- tives. Besides being an oddity _in appear- ance, it. is .solidly built and one of - the’ most elaborate “There were giants’ in those days.” * As a matter of fact, it’ is not a real saul, but a papier mache representation of one, a little over four. feet high. It stands in the Army Medical’ Museum at Washington, and was greatly exag- gerated for pur- poses of anatomical study. The skull is per- fect in every detail. The students study not only the con- struction of the hu- man_skull but meth- ods of trepanning and of mending all the different. varie- ties of fractures. It shelters for flagmen in the state. It is the curiosity-of the locality. aq. eee Ah, yes, a little Mosque where pious Moham- medans may pray. San José knows better. It is a flagman’s shelter made of old scrap is also used in in- structing the classes in dental surgery. Below: A strip of lead _ ribbon about one inch wide, bent so that it will hold flowers upright in a shallow bowl filled with water. Itis used for table deco- ration and is in- tended for small, short - stemmed cut flowers Housekeeping WML LLM K tucaryuataten \o4 A chair seat. with a cushioned coiled spring A convenient indoor clothes-dryer. It is suspended from the ceiling by ropes and pulleys so that it may be lowered to within easy reach and then drawn up again to the ceiling where the clothes are out of the way and where the warmest air is. encountered Made Easy This Below: An egg poacher that takes care of two eggs at a time. A slide bottom makes it possi- ble tolifttheeggs out of the water and drop them directly on the prepared toast without spoiling their shape non - tilt ot agll picture. hanger has three points of suspension This electric student’s lamp has a_= miniature cabinet as its base holding stationery, pens, stamps, etc. An electric iron with a. hinge joint: which - keeps the pipe out of the way A registering disk for the nickel - in - the - slot tele- phone. It checks the number and length of calls Housekeeping Made Easy By merely lifting this door-knob in the manner shown, you lock the door, the key arrangement being integral with the knob and the brass door-plate At last! A jar cap which can be removed without loss of time and temper. When the convex top is depressed the edge springs out from the glass shoulder A cabinet for the small phono- graph. It ‘has the appearance of the _ high- priced machines. The phonograph may be taken out on the lawn or on picnics or to the summer camp, and re- turned to the cabinet for home use With this arrange- ment you can have a drop light and a fan operated from the same socket Below: A mop for dish- washing. It has a hose attachment to the faucet over ae sink “ < Utilities disguised as ornaments. a Under the doll’s draperies is the mucilage pot; beside her are a carved wood twine-holder and a holder: for buttonhooks A mattress made up of three pads which may be used separately upon occasion, as when an un- expected guest must be made comfortable on a couch. ‘The top pad may be taken out and left: to air without any inconvenience 554 Loading Trucks Without Disturbing Sidewalk Traffic : N order to save many steps between their wagons and the loading platform, the truckmen have a habit of backing their vehicles against the shipping platform or against the curb-stone and spanning the intervening Popular Science Monthly Even a Battleship Would Sink If It Were Not Cleaned 25 of our big warships was brought into dock the other day for a cleaning. Two hundred men worked all day scraping off six hundred tons of animal and plant growth from’ its sides and bottom. This tremendous sidewalk with a board or chute. The result in “either case is that you and all the other pe- destrians, find- -ing your path blocked,’ must ‘leave the ‘side- walk and either walk out into the gutter and around the truck: and horses, or climb up a few ‘steps quantity of sea life had ac- cumulated in less than two years, during which time the ship had _ trav- eled many thousand miles. The weight of the barnacles - was so great that from twenty-five to forty per cent extra coal was consumed in to the level of the loading platform’ and down a few steps on the other side. All of which saves steps and-much hard work for the truckmen, but makes the lot of the pedestrian unhappy. Someone who is evidently thoughtful has recently devised a loading chute which is now being used» by. a New York city firm. This chute, as will be noted in the accompanying illustration, is supported by a form of tripod at a distance above AE the sidewalk sufficient to clear the tallest pedestrian, who can pass under it without discom- fort of any kind. Meanwhile the chute, having a suff- cient slant, allows for cases to be placed at one end and slid down by the force | of gravity to the truckmen ready to receive them. The tripod is hinged to the chute, so that it may be folded against it for the sake of compactness. This is an important fea- ture, since the chute is not a permanent structure but is erected: only at stich times as the trucks are loading or unloading. The cases are placed on the chute and slide down: by gravity to the men on the waiting truck A dispatch bearer and his pigeon, which he carries in a special basket to the place from which the bird is sent maintaining the vessel’s' speed. The Carrier Pigeon Still Holds Its Own as Trusted Messenger ESPITE the convenience of the tele-' graph and wireless, carrier ‘pigeons are still used to a great extent in sections of the war zones where the telegraph and wireless are not available. aie The accompanying photograph was made in Salonica, and shows a dispatch bearer and the special basket in which he carries his pigeons. In Paris _ there are numbers of the birds in training. © Underwood and Wnderwood a Popular Science Monthly 555 Shoot or Stab This Dummy, and The By-Products of the Grapefruit You’ll Be Blown Up Obtained from the Culls OOBY traps,”’ as the. British call them, HEN the fruit-grower has marketed are dummy soldiers containing a ' his finest and best specimens of large amount of high explosive. They are’ grapefruit there are likely to remain many death traps set by the Germans for their inferior specimens which would be wasted enemies. Scientifically and painstakingly unless utilized to obtain the by-products. constructed, the dummy shown would have blown to pieces anyone who touched it. Fortunately the British “smelled a rat.” They would not touch it. Careful in- vestigation proved that it was noth- ing more eh... a cleverly- contrived bomb. A descrip- tion of the reached this country does not contain an explanation of how. it could. have been ex- These by- products have _ been found to be numerous. Citric acid is obtained in great quan- tities from the culls, es- pecially from the early winter fruit. Sugar is obtained at the rate of about 4.4 per cent in the early winter fruit and 8.5 per cent in the spring fruit. The peel yields about 2.1 per cent of recover- able oil. A good yield of pectin is also obtained from the skins... This ‘ is a grayish- ploded. The yellow flaky British re- The death-trap left by the Germans in a locality they were mass re- ports have compelled to evacuate. The figure contained high explosives sembling not de- sugar in scribed its internal organism. Conjectures appearance which stiffens on standing in are many. Some believe that a fall water to a clear, tasteless jelly and is resulting from the slightest jolt would used as ‘the basis of many kinds of have caused the explosion. fruit desserts. YOU NEED BOOKS IF YOU WANT TO SUCCEED -You can’t get on in the world unless you read—read the books which will make you more valuable to those for whom you work.. You don’t have to go to college. Edison never went to college. But he has probably the finest library of technical books in this country. If you want helpful, practical books on any subject, write for POPULAR SCIENCE MONTHLY’S new BOOK CATALOGUE. The books described in it have been carefully selected by experts. Write today for the new book catalogue. It’s free. Popular Science: Monthly, 239 Fourth Avenue, New York City. One-Piece Ships of Stone - _ Already a company has been formed and financed to design and build concrete ships of 4,500-ton capacity By Joseph Brinker Broadside vie view of 550- ton concrete barge used by Rrenctel Sand cick Gravel Company of Baltimore, Ma. This picture was taken just before the barge was launched. The barge has been in use for several years ONCRETE ships are possibilities. They may be built in addition. to -steel and wood vessels to offset the acute submarine peril. According to au- thorities, ‘the German’ U-boats are sinking Allied and::neutral tonnage much faster than it can be’renewed. -This cannot go on. If it does, we'shall lose the war. Even our Government-controlled shipbuilding program for steel. and wooden ships will not produce sufficient tonnage to offset the present U-boat toll unless this tonnage is greatly increased by the use of some new substance. Concrete seems to be this sub- stance. Already a large com- pany has been formed and financed in San Francisco to design and build sea-go- ing vessels of 4,500-ton ca- pacity to be made of re- enforced concrete. Plans now drawn up show these vessels to be three-hundred feet long, with a beam of. forty-six feet and a draft of twenty-four feet. The con- crete hull is to be six inches thick and the steel re-enforc- ing rods are to be welded together to reduce the quan- tity of steel réqtiired to a minimum by avoiding the waste from laps and _ bolting otherwise necessary. It has been calculated that thesteel re-enforcing for the vessel will weigh less than the bolts needed in a Me Steel re-enforc- K ing rods —— Wood rail. Slice .cut away to show wood ship and that the completed hull will weigh less than that of a wood boat of the same carrying capacity. Allan Mc- Donald, the designer of the ship, estimates that it can be built in ninety days and that turbine engines of ‘two thousand five- hundred horsepower will be sufficient to drive her at.a speed of fourteen knots, which is considered enough to enable a boat to escape a submarine under ardinary conditions. There is no question about the avail- ability of the concreting materials and that * “Steel frame work Centerline keelsor re-enforcing bars incased in concrete ON ye ee The Mid-Ship Section of a Concrete Boat It would be made up of light steel framework with wire poe ie onthe sides. The concrete covering is shot into:place: by compressed air. east .in forms in the usual way.: Pouredconcrete has much fea densitythan that shot into place and is liable to be more porous than the kind placed under-pressure. is shown cut out of the boat from lower deck to lower deck in order to indicate'the position of the steel re-enforcing rods Rese longitudinally through the framework tom of «the vessel is 556 the use of artificial stone opens up a new avenue to the. increased production of ships. Even with plans drawn, however, the actual building of such a large concrete vessel and its practicability after it is built, are entirely different matters.: While every one knows of concrete’s adapt- ability to . almost any form: because it is handled in a plastic or semi-fluid state; of its fire- proofness; of its general use in large office buildings, in private residences, in bridges, docks, sidewalls and in practically all branches .of con- struction, there is yet much to be done-by naval arch- itects and marine engineers before the five-thousand-ton concrete sea-going vessel is a practical, commercial certainty. does not mean that such a ship is an im- possibility but that American ingenuity _ Popular Science Monthly 557 _Upper dech\ ballast oe fuel oil A Typical Cons Saigo Boat It has two decks, a double bottom for ballast or fuel, and a double hull between the lower deck and the double bottom. This gives greater strength. The well known principles of concrete building construction are indicated in the form of the hull members and the method of distribution of the steel re-enforcing This ~ How the Concrete Hull Will Be Made Imagine this man standing on the scaffolding alongside a ship, and you will get an idea of how the three layers, of the hull are shot into place by, compressed air. The man shown here is building up a some- what similar concrete slab on metal Jathing to form the outer wall of a sewerage disposal plant. The cement is shot through a hose and enterprise must be brought to bear and problems peculiar to concrete con- struction solved. ft The Concrete Vessel Is Not New in Shipbuilding Concrete vessels have been built in the past. But they have been small barges or the like for inland water work, with but one or two exceptions. One of these “is: a - three-thousand-ton concrete vessel now under course of con- struction in Moss, Norway. She is ex- pected to be deliv- ered to her owners es by the time this arti- = cle appears in print: The first concrete boat really ._ dates back: to 1849, when M. Lambot, of Carces,' France, built-a. small ten- foot rowboat of re-enforced concrete. While the boat and construction were French Government, the vessel was. evi ~ + dently ~ far intadvance of. its its:: method of investigated by. the time, and its ‘further develop- ment was left in private hands. Almost fifty years later, or-in. 1899, Carlo Gabellini, of Rome, Italy, built-~several: cconcrete scows and barges, one ‘of: the latter a one-hundred. -fifty-ton vessel for the city of Civita Vecchia. Meantime, small eleven-ton concrete barges had been built in Holland in 1887, and later, a two- hundred ~ twenty-ton freight barge in 1909 by German = shipbuilders at Frankfort - on - the- Main: In 1910 a similar concrete barge was built for use on the. Welland Canal, Canada, while in I9II, barges or’ pontoons made of concrete were successfully built and employed in work at the Panama Canal. In 1912, Oscar F. Lackey, then harbor engineer - of Baltimore, Md., built: several five-hundred-ton barges, one of 558 which is shown in the illustra- tion on page 556 of this This has been in use for more than four issue. years and is still giv- ing satisfactory. service. Advantages of Concrete Ships ~ Re-enforced con- crete barges seem to have given good service, so that the present problem of building self-pro- pelled: ships of four- or five-thousand tons capacity is one of construction methods and of tak-’ ing care of the severe’ strains of ocean travel and the vibra- tion of the engines.’ These conditions concrete has * many advantages* met, not enjoyed by éither wood or steel. be fireproof’ and would require less main- tenance than steel vessels because of the elimination of taping and painting to avoid deteri- 3 Beam knee | oration © due ae: Deeks re-enforcing badas. } to rusting. . Also, their bottoms would need to be cleaned less often be- cause sea .- sr! , d pro eahe die Outside of barge not attach fe Sectici ransverse ction egies hee Through Deck and readily to Part of.Hatch concrete as to steel and wood. Some. advocates of the concrete vessel claim . that it can be built at less off cost than a concret Above we have a good illustration of the man- ner in which the con- struction of the concrete * boats will follow the usual methods--of con- crete building in regard to re-enforcing. the wood bumper stringer bolted to the . concrete hull to ward collisions, which might-tend to crack the Popular Science M i ak recat pn Tn. Ver tical holding rods, — <— * gig e2:- ates The Cement-Gun Rod Re-enforcement ., The T-bars used in the side of the concrete ship are made by shooting the material into place. The spacer bars have holes through which are inserted short rods with hooks to carry the horizontal bars on which the three layers of re-enforcing wires are hung. By this means the wire is kept always in its proper relation ‘Concrete ships would Hatch coaming \I Beart*knoes 4 , Inside of barge E j Longitudirst ot Note ship of steel or wood, that it~ ‘has:.a Longitudinal steel. re- enforcing rods longer life than either and that less skilled labor is re- quired. While this ‘may be true in the case of small barges and the like on which actual: ‘cost figures are available; “it remains to be proved in the case of the large ocean- going freighter, The standardized cargo boat of either steel or wood as planned by our Shipping Board will be built in much less time . than any other ships constructed | here fore. © - Pay Followinat previ- ous re-enforced con- crete construction methods, the pro- posed concrete ves- sels may be built along two general lines—one by the use of forms, as in most building work, and the other by the tru theform tie the three vertical deck sup- ports and 1 beams Popular Science Monthly plastering-like method in which a very dense but fluid mixture of cement is shot into place by means ,of compressed air. The former type is the most common and may be made with or without double-bottoms, or with single or dual hulls separated by an air space which may or may not be employed to carry fuel or water ballast. © Both types of con- _. struction areshownin 7 the accompanying perspective and de- tailed sketches. How the Ships Will Be Built The method by oat which the concrete is shot into place by means of compressed air as advocated by Carl Weber, a con- 7 crete engineer of Chicago, is really an adaptation of the “cement gun”’ process previously described in the PopuLaR ScI- ENCE Montu_y. This method makes use of a light steel frame- work for the vessel. attached aseries of re-enforcing rods carry- ing wire mesh: or other flexible re-enforcing, each of which is.in turn covered ,by thin layers of concrete forced against one another in the applying so that the whole is a ho- mogeneous mass of such a nature that the line of joining one layer with the next cannot be detected if the slab is cut across. The details of all of these methods are shown in the ac- ie oaeol Ist laye Joining of layers applied at different Sines r layer 3°4e A Section Through the Side The T-irons, spacer bars, hooked rods and wire. mesh of a shot-into-place concrete boat are shown. three -vertical lines between the ragged lines indicating the wire mesh show roughly the thickness of each layer ‘To this framework are + 559 is an important advantage because of the first cost of the forms; their difficulty of construction due to the unusual shapes at the extreme front and rear ends of the vessel and the cost of setting up the forms and moving them from point to point on the. vessel after they have been re- moved from sections already ' poured and hardened. The advocates of the pouring method have planned to over- come the. difficulty and cost of moving the forms by devising a cheap, steel frame- work both inside and outside of the vessel along which the forms may be pushed with- out lowering them to the ground. Unusual-shaped forms for. the forward and rear ends of theves- sel. may. be. provided by the use of collapsi-. ble steel forms such as are used in_ bridge culvert work. Outside of ship Vertica}.mesh » holding rods Spacer bar “amsverse section. thrdugh concrete hul nd last layer” The Clang! Clang! Make Way for the ; ’ ~ Chinese Ambulance NE of the reasons why the people of J the Occident-are generally disposed to agree, with Bret Hart that ‘‘the heathen Chinee is peculiar” is the unusual method of the Chinese in handling the sick. Notice the ambulance in the photograph, in which a dying man is being transported. It is of wicker basketry of the same type as that used. for companying il- lustrations. The great ad- vantage of the compressed-air conveying pigs and poultry to market. Crude as this type of convey- method of shoot- ’ ance seems, . no ing the concrete > KERRY’ rubber-tired int place, is that ‘ =e = automobile could it eliminates al- a : + ENN \ travel with less most one-half of the wood or steel forms necessary © ‘jolting. The car- riers work in re- lays, goingslowly, if the ordinary pouring method is pursued. This The Chinese ambulance. veyance in which pigs with a kind of swing, and _rest- It is just like the con- : : ing at intervals. are taken to market I Rollers O 4 @ | a aa Ot’ at) One Popular Science Monthly Gold-Plated Teeth for Sheep 5, » Are Common in Scotland HE sheep of the western islands 4 of Scotland are almost as sty- lish as the dogs that ride in auto- mobiles on our own Fifth Ave- nue, in New York city. The canine aristocrats have occa- sional cavities in their teeth - filled with gold, but the Scot- tish sheep have their entire set gold-plated before they. have any chance to decay. The gold-plating is due to gold dust in the soil. As early as 1536 Hector Boece, Bishop of Aber- deen, speaks of the remarkable appearance of the sheep that roam “the golden mountain” in central Aberdeenshire. Their wool is yellow, «their flesh is red, flecked, as it were, with saffron, and their teeth are the hue of gold, he says. To Keep Out Burglars, Leave Your Key in the Door D. E. CURTISS, of Spokane, Washing- ton, has invented a key-hole guard. Leave your key in the door at night, and it will be impossible for anyone to insert another key in your door. The guard can be fitted to any door. It consists of a plate which slides horizontally just in front of the body of the lock, and in the inner side of the door. On locking the door from this side, this plate is moved by turning a knob. The shank of the key, being horizontal, is caught and held in the horizontal slot in the plate that has just been moved. At left: A plate slides front of the body * of the lock and on the inner side of Horizontal key slot Lock plate key hole key is caught in slot and held so that nothing from the outside can move it 591 The combination suit which is an excellent substitute for waists and skirts or shirts and pantaloons The Overall Has Entered the Fashion Sheets OR the first time, perhaps, since the days when Indian women tilled the land while their lords and masters hunted or fished or fought, American soil has felt the pressure of the feminine foot on spade and fork. It has been no light, inefficient pres- sure, either, nor is it hampered by skirts. The approved costume for the really-in- earnest farmer, whether man or woman, is a combination overall suit, which not only affords perfect protection but is comfortable and easi- ly put on. The illustration above shows the different styles applicable for wom- en’s wear. Those for men are very similar in design. | They are made of khaki, just in the door denim or other suitable ma- terial. Even the children ‘are not left out. Their suits are made exactly like those of the adults, since Door key hole~ ‘Lock plate ; Nees ° to right their bit in the farm work is The shank of the equally as important. Khaki hats meet the ap- proval of the youngsters for topping off these utility suits. Women prefer the old-fashioned sunbonnet. horizontal A Lift Deck for.Automobile Freight Cars It doubles the automobile capacity of a car and does not interfere with the shipping of other goods N shipping automobiles in car load lots at the present time, a temporary deck or floor is built within the car at the time of each shipment. On this, one row of automobiles is placed above another row loaded on the main floor of the car. In this way the capacity of the car is prac- tically doubled. But this method of utiliz- ing space is expensive and it injures the car to have the decks continually in- stalled and removed. Consequently the automobile shipper is up against a serious problem. Joseph C. Youngblood, of Atwood, Kan- sas, has invented a lift deck which seems to meet all requirements. The mechanism necessary to operate the deck will in no way interfere with the shipping of goods other than automobiles. The deck can be lowered to the car floor so that automobiles can be loaded upon it with ease. It can then be raised to its elevated position and. automobiles loaded into the lower portion of the car with- out interfering with it. The lift deck is raised by means of pistons traveling within four cylinders.. The lower ends of the four cylin- ders extend below the car floor and are connected with a pipe that extends to a tank containing oil and a pump. raised deck Position of automobile when raised on Jift deck Automobile under The upper lift deck for automobiles and the mechanism that elevates it An electric motor and the pump which it operates are contained in a separate com- partment carried under the car floor. The oil supply tank is situated next to the pump. When the deck is to be raised the motor is started and the pump forces oil from the storage tank into the pipe line and thence into the cylinders to force the pistons up- ward. When the deck, with its load of automobiles, has been raised to its upper- most position, pins are inserted in the cylin- ders to hold the deck permanently in position. This prevents any possible back- flow of the oil from the cylinders and re- lieves the cylinders and pipe line from continued pressure. When the deck is to be lowered, the pins are removed to permit the free movement of the piston rods. After reaching its destina- tion the car can be unloaded without any additional equip- ment or tools. The automo- biles on the car floor are first removed and when they are all out the upper deck is lowered and the cars on it removed as were the cars on the deck floor. Spaced floor i] plates support the automo- \ biles while they are being ~ shipped, but wooden beams can be substituted. The sup- ply tank, pumps and motor may be placed in any part of the car that is convenient. Lifting - mechanism The lift deck takes the place of the expensive temporary upper deck and does not interfere with the carrying of goods other than automobiles. It can be raised or lowered in a minimum of time You Can Roll This Can Without Popular Science Monthliy Spilling the Garbage T looks as if the ideal garbage can had been invented atlast. William Dowie, of New York city, is the inventor and his can is about everything that a garbage can can It is dustless, noiseless. You can without spilling it lid is clamped tight across the The lid prevents flies, top. : dogs, cats, mice from touching the contents. It is strictly a non-disease rubber bumpers on. the top and bottom which make it practically noiseless when it is being rolled across the. sidewalk or street and dumped in a wagon. thermore, the rubber pro- longs the life of the can, protecting it against rough spreading can. There are handling. Drilling with This Electric Drill Is Like Shooting a Pistol LECTRICITY is rap- idly tak- ing all the back- breaking exertion out of every kind of work. If all the inven- tions based up- on it turn out satisfactorily and as many more are brought out in the future the old axiom about earn- ing our bread by the sweat of our brow will lack pun- gency. Look at the electric drill shown in the accompany- ing photograph, for instance. It is 598 patterned somewhat after a pistol and by its use a hole can be drilled in iron or steel with the ease of shooting a pistol. This electric drill has a trig- ; eet -like on-and-off switch which makes it possible to handle the instrument without fatigue. The trigger switch also prevents the breakage of drill bits for the reason odorless and be. turn it over because the tent and rats Fur- The lid on the can prevents the contents from spilling and keeps flies from spreading disease ing illustration. The cover a hole into a hard-to-reach spot with an electrically operated pistol-shaped drill ** Shooting ”’ that it is possible to control the drill without releasing the grip to the slightest ex- and allowing the weight of the-device to sag on the drill bit. The workman instinct- ively pulls the trigger to shut off the current when the drill bit passes through the metal being drilled, thereby saving cur- rent expense. The chuck spindle can be adjusted to fit all sizes of bit stocks so that the drill can be used in nooks and corners where there is not much room, and in hard- to-reach spots, as shown in the accompany- of the motor armature of the drill is per- forated for cooling to’ prevent over- heating. The drill weighs a trifle over thirteen pounds complete and drives the bit at nine hun- dred revolutions per minute with no exertion on the part of the operator. The ease with which it is operated is not the only at- traction of the elec- tric drill, however. The hole is made in a small fraction of the time required by the ordinary method and is per- fectly clean and true. 594 Even in the dark you would know that the bottle above with its skull and cross-bones mold contained poison The points over the cork of the bottle on the right would warn you that you had the poison bottle in hand These Bottles Warn You That They Contain Poison N a bulletin on poisons, issued from the Surgeon General’s Office at Washing- ton, D. C., it is stated that every year five thousand people, on an average; take poison by mistake. The Surgeon General recommends that poison be sold Ee and kept only in bottles of dis- Ai tinctive shape. The bottle shown | in the illustration seems to be ideal for the purpose. Even little children and the most illiterate adults usually know that the skull AN ee SS ~ SS SANS x SNR AS A finger print showing imprint Popular Science Monthly : in the glass, so that when the bottle is taken up at night in the dark it is easily distinguished by the sense of touch. There is a smooth space left on the side of the glass on which labels telling the kind of poison that is contained in the bottle may be pasted. But should the label drop off or become defaced, the fact that the contents of the bottle are poisonous will be obvious from the shape and design of the bottle itself. Another design is the invention of Worth R. Barringer, of Colorado. A metal clamp fits around the neck of the bottle and pro- ‘jects two pointed segments over the cork, holding it in place and by a slight prick warning the person attempting to withdraw the cork that the contents of the bottle are poisonous. Is This the Secret of Curious Lettered Finger Prints? N the April issue of Popu- LAR SCIENCE MONTHLY, .on page 517, there ap- peared an article de- scribing a curious fin- ger print. A Nation- al Guardsman had his finger print taken and was surprised to see the letters “U O © P L E” on the ball of his right fore-finger. He was unable to give a reason for their pres- ence; furthermore, he did not know they were there until an imprint was taken of the finger. Now comes an explanation of the method by which the mysterious letters were imprinted on his finger. W.K. Evans, director of Evans University, in Chicago, Ill., offers us the following: “In order that you may enlighten those who may have wondered how the lettering got on to the print, I send a finger print with the words ‘Chicago’ and ‘Wilson’ plainly visible on the ridges. “A rubber stamp was pressed down on the glass slab after the ink had been rolled on it, and the tip of the finger had been lightly inked. The inked finger was then Bele fF -th d ° and cross-bones indicate danger. “Chicago” and pressed down on the lettering of The pattern is molded deep ‘‘Wilson’’ thestamp. Thismadetheimprint. . Popular Science Monthly Kitchen Luxury—The Ivory Pie-Crust Trimmers of New England EW ENGLAND has long 595 been famous for pie, which, if it is not the actual staff of life, at least runs the other food con- tributions a close second. In the old Dartmouth Historical Museum in New Bedford is a curious collection of quaintly carv- ed ivory instruments known then as now, in the old New England households as piecrust crimpers. New Bedford was at one time the greatest whaling port in the world. A whaling trip is by no means short. The average trip was one year. Ofttimes three or four years passed before the whaler would reach his own shores again. No doubt with thoughts of home came visions of the pies for which their house- wives were famous; for most of the curious pie-crust crimpers were carved by the whalers during their idle hours at sea from the ivory which was part of their catch. The pie-crust crimper consists of a handle and wheel which has a crimped edge so that when it is run around the sheet of thin pie crust dough it cuts the dough out with a fine serrated design. Trimmers were used not only to cut around the border of the pie but also back and forth along the top of the crust. In baking, the openings spread, leaving beautiful leaf and flower designs on top of the pie. The envelopes are fed automatically by a turn of the typewriter platen Let This Automatic Device Feed Your Envelopes SIMPLE machine designed to in- crease the cfficiency of typists by auto- matically placing envelopes in proper posi- tions in typewriters has just been put on the market. The instrument consists of a framework attached to the machine and operated by the ordinary space-line lever. With one turn of the typewriter platen, the addressed envelope is forced up and out from the roll and the next one simultane- ously and automatically placed in the proper position to receive the next address. From four to six envelopes can be ad- dressed per minute by an amateur typist, thereby allowing the higher- priced stenographers to con- centrate on letter-writing; or the time saved will permit the same stenographer to do more work in the same time as formerly. The automatic envelope feeder consists of a magazine beg =a holding one hundred and fifty envelopes and ‘a framework having four steel fingers, two above the others. The upper ones, one on either side, press down on the uppermost edge of the envelope and force it behind the platen, adjusting it in a straight position. The two lower fingers engage the en- velope inside of the flap and push it from the magazine Ivory pie-crust trimmers made by the old whalers who used to put in at New Bedford down behind the roll, after which the address is written. 596 It Has Stopped Raining? Then Pack Your Water- proof in Your Bag RAIN coat suitable - / for the traveler / weighs only thirty-two ounces and folds into a neat envelope when not in use. It is also useful to the motorist and to others who feel the need of being protected against in- clement weather and wish to avoid carry- ing heavy garments. Though light the rain coat makes a smart appearance, and it is so small when folded that you can pack it away in your handbag. | A special bag is pro- vided for it, however, which is neat and incon- spicuous. folds Bomb Exits for America’s First Portable Hospital 1 the heart of New York city there are a umber of trim frame buildings which form America’s Popular Science M onthly When not in use the rain coat into a neat What You Will Need When You Go to the Training Camps F you happen to be one of the fortunate ones chosen to be transformed into officers at one of the training camps, your first impulse will probably be to pur- chase a nifty uniform, two or three pairs of classy looking shoes and a supply of vari- colored ties and socks. But nip that There are few things you will really need these will be supplied you by your loving Uncle Sam; or if you must pur- chase them, you can buy them from the Govern- ment for much less than from the trade. The things you will really need and which the Government does not supply are towels and plenty of handkerchiefs. It would be advisable, too, to take with you a pair of slippers and a light bathrobe. A raincoat might be made envelope first portable hospital. The buildings are constructed so that they can be taken apart and set up in another city within two days All windows’ are made so that the air is ad- mitted over the heads of the patients, pre- venting adraft, and bomb exits are provided ‘every few feet. The bomb. exit is a section of the wall which toserve instead of a bathrobe and answer its own purpose as well. Have a light roll stocked with your own pri- vate toilet arti- cles, and supply yourself with a fountain pen and colored crayons for map-drawing. Cross entirely off your list of essentials the civilian suit, neck-ties and white _— shirts. You will have no time to wear bomb exit which The both the patients and the nurses of a war hospital swings out and drops. affords a quick escape for anything but your uniform. impulse in the bud.- at camp and most of — . 4 4 . «oie ** de AS ac: Machinery Made from Scraps The material from which it was made was strewn about camp, and was mere junk = 2 = : _bolts, etc. HEN the time came to pave the top of the Kensico Dam, in New York, the superintendent, George H. Angel, didn’t go to the extra expense of purchasing new paving equipment: He took a hurried inventory of the odds and ‘ends of machinery that lay about the con- struction camp and decided that he could make some machinery of his own out of them. ~ Our illustrations show what he did with a few pieces of discarded pipe, wheels, nuts, A roller was made by fitting an old belt-pulley with a wrought-iron handle. The asphalt-heater was made out of an old steel form that had been used for casting concrete blocks. By riveting in a false bottom near the middle of the form, cut- ting a door in the lower half at one end and riveting on a hinged cover and smoke stack, the heater was ready for use. The asphalt was placed in the upper half and a wood fire was built underneath the false bottom. The mixer for the mortar was made by joining flanges to the ends of a short length of riveted steel pipe and by bolting cover plates to them. An axle with paddles ran through the center and the propelling force was a small motor placed at one end. The machine was mounted on an old: wagon y- The roadway across the top of the dam An old steel form for concrete blocks was converted into a heater is twenty-one feet wide and two thousand, five hundred feet in length. There is a cement sidewalk on one side and a concrete curb on the other, each about eight inches above the surface of the roadway gutter. The forms for the concrete were all made from scrap material which was readily obtainable at the camp, and a locomotive crane was used to transport the cement from the mixer to the roadway, where it was spread by hand. The machinery made from odds and ends gave as good service for the purpo e as new machinery. The mixer for the mortar is a complex affair. It is mounted on an old wagon body =a The roller was made by equipping a discard- ed belt-pulley with a wrougat-iron handle 597 598 A Lumbermen’s Camp Which Can Be Moved from Place to Place on Rails N his account of the life of the rough and ready northern woodsman, Rex Beach often painted a realistic picture of his poorly-constructed and unsanitary home. As a rule, lumber camps enjoy but a tem- porary existence, and for this reason the houses are ramshackle affairs. The logging crew live in them a few weeks and then move on to another camp. The old camp is left at the mercy of the elements and no attempt is made to Popular Science Monthly ; Pointers for the Inventors Working on the Submarine Problem HE Naval Consulting Board has re- ceived literally thousands of sugges- tions and plans for destroying submarines and protecting merchant ships against torpedo attack. In addition, the Secretary of the Navy has also heard from inventors on the subject. The Naval Consulting Board has considered these plans and apparently has come to the conclusion that most if not all of them are worthless. In Bulletin No. r repair it, unless the loggers happen that Way again. In Everett, Washington, the temporary camp has been replaced by a permanent mobile camp- con- sisting of railroad coaches. The coaches include kitchen, dining and bunk rooms for the which was published recently by the Sec- retary of the Con- sulting Board, No. 13 Park Row, New York city, and which bears the title ““The Submarine and Kin- dred Problems,”’ the difficulties that must be considered by the inventor are in- structively summar- ized. That Bulletin ought to be in the men, blacksmith shop, engineers’ and administrative offi- ces, as well as equipment for heat- ing, lighting and water supply systems. When the logging company wishes to move its camp to another part of the country, the cars are taken to that section by locomo- tives. Thus the camp cost is not only cheaper, but the men live amidst surround- ings that are as near ideal in point of con- venience as the local conditions permit. The interior of the blackmith.shop in the portable logging camp. There are facilities for every kind of mechanical work that could possibly be needed hands of every man who thinks that he has solved the sub- marine problem. It disposes of the electromagnetic devices suggested for detecting and destroying submarines; it dismisses the idea of “charging the sea with electricity’’; considers the best and worst methods of protecting a ship against submarine attack; dwells upon the _airplane as a device for discovering the sub- marine;comments on underwater sound-re- One car supplies steam which heats all the cars, and an- othercarcon- tains a dyna- mo which provides cording de- vice, work- ing on the microphone principle; brushesaside the use of h-e-t Sion screens as a current for protection one hundred for cargo- and sixty- carrying four incan- ships, and descent points out lights. A the merits third car is and defects devoted to ones ; of present bathrooms This logging camp consists of railroad coaches which have methods of and laundry. their own heating and lighting plant, The camp is portable destruction. ae DS Ty Makins It Easy to See the “Movies” How tedious inserts can be avoided end kow the clock can be watched Billings, any explanation that needs to bemade ina motion-picture can appear at the same time that the action is going on. The inventor calls his contrivance for projecting captions a “‘descriptograph.”’ In general appearance it looks not unlike an ordinary stereopticon. In the place where lantern slides ordinarily go, however, is a large disk having a number of radial openings. These radial openings contain the captions to be thrown on. the screen and go through the field of the lenses on the lantern one after another, being moved along by an electromagnet, one radial open- ing ata time. On the film are little metal rivets or eyelets. When the film slides through the guiding and feed ° rcllezs, these metal rivets make an electrical contact with the rollers, completing a_ circuit through the electromagnet on the auxiliary lantern, or ‘‘descripto- graph,” down in the orchestra pit. This causes the descripto- gr2pa to throw a fresh caption on the screen. Just before the ac- tion on the main film is to change again, another rivet appears on the film, makes proper contact, and causes the electromagnet to x iA Bilkos to the invention of Dr. J. W. for The disk which contains the captions printed for the screen in radial openings The brass eyelet is the space left the caption High power, tungsten pales @\ Hour hand attached Stn er wheel advertising / Clock mechanism > Drive gear Revolving dick A- machine for projecting both advertise- ments and a clock-face to tell the time of day pull a new caption into place. The whole plan is here illustrated. Another device somewhat like the descriptograph is also being marketed. This contrivance, however, is for the purpose of projecting advertisements in- stead of captions. It has a special screen of its own, much smaller and to one side of the main screen as is shown in tke il- lustration. In conjunction with its advertisement-skowing fea- tures, this machine also projects the hands of a clock and a clock dial at the same time, this latter feature being an integral part of the advertisement. Since people attend- ing the show will inevitably look at the clock now and then to keep track of the time, the clock serves the special purpose of attracting attention to the advertisements. As is shown in the illustration, the clock hands project inward from the rims of two large and hubless gearwheels through which light from the lenses of the lantern passes. In practically the same focal plane as that of the hands a wheel revolves in which are some half-dozen regularly spaced openings about the size of a quarter. Transparent celluloid disks cover these small openings, and on these the advertisements are painted or printed. By means of a suitable escape- ment device, this wheel shows six adver- tisements in rotation. 50a 600 A Woeden Lighthouse Candlestick ‘and How It Is Made T is easy to make a wooden candle- stick in the shape of a lighthouse. The one illustrated is about six inches high and about four inches in diameter. The lighthouse is white, with yel- low and red ornamentation; the windows are painted. The saucer in which the lighthouse stands can be used to receive burnt matches. It is nailed or glued to the lighthouse. Every lighthouse keeper has a daughter. Carve her out separately if you like and glue her into the saucer so as | to have her leaving the door. Let her dress be yellow and Popular Science Monthly tures to the exhaust pipe. The exhaust part of the valve opens limit of its downward travel on the power stroke. As the piston approaches the top of the cylin- der in the usual manner, the valve is rotated counter clockwise by means of gears which are securely fastened to the crankshaft and valve respectively. They are ina ratio of two to one and are tied by means of a suitable belt or chain. | The by-pass in the valve remains open until the piston has reached the limit of its upward travel. When the piston starts back the aper- ture in the valve is rotated opposite the aperture in the her belt: red. The depth of the saucer is about two inches. It is painted red. These colors can be varied to suit the tones of the room or the owner’s fancy. A hole is cut.in the top of the lighthouse to allow the candle to be placed inside. - decoration. Getting Rid of the Poppet- Valves on a Gasoline Engine © HE trend of the times in engine construc- tion as well as in every other kind of manufac- ture is toward simplicity. wa Wherever one thing’ can be made to do the work of two or even more parts, nothing is left untried to facilitate the merger. A western manufacturer has brought out a new gasoline engine in which the poppet- valve, camshaft and associated parts are eliminated and a common rotary valve substituted in their stead to perform the same functions. When the rotary valve is in a position opposite the apertures in the cylinder head, the burnt gases pass out through the aper- Section through in- take and exhaust portion of cylinder head on angular line gas supply The lighthouse candlestick makes a pleasing table The colors are varied to suit the fancy — der. Water in cylinder head. The influx of gas is through the aperture in the cylinder head, through the rotary valve and its aperture, and through the aperture in the cylinder head to the cylin- The valve aperture remains open until the piston has reached the limit of its downward travel. In this way the mechanism of the engine is so simplified that there is little chance of anyt ing getting out of order and the life of the engine is considerably lengthened on account of the elimination of friction. When the rotary valve is opposite the apertures in the cylinder head, the burnt gases pass out: through the apertures to the exhaust pipe when the piston has reached the _ A Simple and Attractive Loading Coil RDINARY loading coils are often made in very compact form, as when wound between two hard rubber disks. Though very neat in appearance, such coils are hard to make without the aid of suitable ma- chinery for turning out the rubber disk ends, which are expensive if bought ready made. If the method of con- struction de- scribed in this article is used, however, such ‘coils can be easily made ina few minutes at a very low cost, and not only will they give the best of satisfaction, but they will present a very smart appearance. The principal feature of this coil is embodied in the ends, which are small ten cent disk phonograph records. These can be bought for about five cents apiece second-hand at a record exchange shop, or in many cases at the 5 and Io cent stores, wherever old records that do not sell well are reduced in price. These composition disks are about 514 in. in diameter, and can be separated any desired distance by cardboard washers. The remaining space around the circum- ference of the cardboard and between the walls formed by the records is wound with fine wire, say about No. 28. The records can be turned so that the grooved sides face each other, thus leaving the smooth faces turned out and displaying the patent dates and numbers which are embossed on the bottom of the records. The composition and cardboard disks are held together by binding posts passing A coil of wire placed between record disks Amateur Electrician 7nd Wireless pete Pe them near the center, or by several small copper rivets, arranged in a circle. These rivets may be used as con- tacts for a rotary switch, with which the inductance of the coil can be varied. After the holes for the binding posts and rivets have been made, and before the wire is wound on, all the disks to be used should be shellacked together in the proper positions, and dried under a flat weight of say 5 lbs. The coil illustrated is a single step affair with only two binding posts. By making two separate windings, and fitting the coil with four binding posts, considerable ad- vantage is obtained over the single step type. With the latter scheme the instru- ment can be used as a straight tuning coil with two variations of inductance, or the separate windings can be so coupled as to form an inductive tuner. It can be used to increase the wavelength range of primaryand secondary of any loose coupled tuning coil. Instruments made in this manner must be handled with reasonable care, both in the making and use, as the composition ends, while almost as-strong as hard rubber of the same thickness would be; are too thin to be banged about indiscriminately. However. in case of breakage the cost of renewal is slight.—R. V. CLARK. Using a Bicycle Pump for a Water Rheostat WATER rheostat can be quickly made from an old bicycle hand-pump. Remove the metal cap through which the rod passes, and substitute a plug of wood or cork. Through the center of this plug a hole should be bored, its diameter being identical with that of the rod. Next remove the plunger disk and thoroughly clean the rod so it will be free from grease or rust. Wire leads should also be soldered to both casing and rod for electrical con- 601 602 nections. After closing the old air outlet of the casing, fill the pump chamber with water, and push the plunger through the hole in the plug. After the rheostat has been connected in an electrical circuit, a resistance of varying degrees may be obtained by merely manipulating the pump handle. This apparatus is very useful for experimental work, where it is necessary to have a very careful regulation of the cur- rent.—K. M. COGGESHALL. Transmitting Wireless Messages Underground Without Aerial IRELESS messages can be transmit- ted without any aerial by using at each station two ground terminals not less than 200 ft. apart. One ground should ex- tend but a few feet below the surface of the earth; the other should be sunk to a much greater depth, or better still, attached to a gas or water pipe. The receiving instruments are the same as when an aerial A transmitting set with ground connections for sending messages without an aecial is used, but at the transmitter a buzzer replaces the spark coil. An _ ordinary buzzer may be used with a thumb screw to tighten the armature so as to obtain a shrill hum rather than a buzz. A taut piano wire is even better than an armature. A small, portable outfit can send and receive up to five miles by using a water- pipe ground, or up to three miles by using two ground rods at about 50 ft. apart. In the country, where there are no_ local electrical disturbances such as those caused by trolley cars, a tuner is unnecessary. For station work a tuner should be used, and an army field buzzer generating high frequency currents will considerably in- crease the sending radius. Popular Science Monthly - Using an outfit very similar to the one ~ described, Dr. H. Barringer Cox, of Santa Barbara, California, has succeeded in sending signals some forty miles. He u | Phonde Se ee : Detector , : S | i ; oN AN Metal plate Ground PARED LT A Diagram of connections with the instru-— ments and the ground for the wireless set declares that with a few slight changes he will be able to increase his sending radius to twice that distance. When perfected, this system may be valuable in military field work, as it does away with the necessity for laying a telegraph line or erecting an aerial.—J. E. Hasty. A Flexible Spline Used for a Draughtsman Curve F one adjustable curve could be ob-— tained draughtsmen would readily ap- preciate its value and prefer it to others. The illustration shows such an adjustable curve-making device that is simple and — convenient. With this device it is possible to obtain a great variety of curves quickly and easily, that will fit to a fraction of a degree. Another advantage of this curve is that an arc of a given radius may be -drawn any length desired. i OL ve curve that is adjustable to a fraction wa a degree to make an arc of a given radius The curved piece A may be made of steel or suitable celluloid. The fine threaded rod. B connects the ends of the bow at C and C. A thumbscrew £ is used for adjusting the bow to obtain the required curve. The device may be made in any size.—NEy., Sending Wireless Messages Under Fire Mobile wireless stations on the western front By Captain A. P. Corcoran, Late of British Army inventions that have been developed > during the great war—inventions _ that have displayed not merely human but _ diabolic ingenuity in their effectiveness in _ destroying human life. There are the British “‘tanks,’’ and the German gas bombs which have accounted for many a good man. But not all © are of such deadly character. Side by side with these weap- ons of destruction are many of more enduring worth, and high among these rank: the motor wireless trucks, or lorries as they are called in England. It is quite impossible to overestimate the importance of wireless in the great war, but the part that it plays differs with ‘the character of the fighting. No army now but is equipped with wireless con- trivances. The French use the de Forest system; the Rus- sians and Italians, the Mar- | coni; the Germans and Austrians, the Telefunken; and the British use two sys- tems. One is the Leyland, the other is the Marconi —the standard1¥4 K.W. set—fitted in a Daimler motor truck. But though they all vary in de- tails, in principle ay i have heard much of the amazing ae ' 2 hh eee etd nredis lron clamp to hold mast Socket for hee) of mast Captain A. P. Cor- coran late in active service in the British Army in France Multiple tuner, Detector, Transformer, Rotary, Condenser, Etc.” they are the same. They are alike in all essentials, A more compact contrivance than this traveling station it would be ex- tremely difficult to find. The body of the truck is about 12 ft. by 6. The entrance, of course, is at the rear. At the far end of the car is a bench 3 ft. high by 4 ft. deep, _on which are placed the multiple tuner, the magnetic detector, the magnetic key, the operating key, telephone condenser and earth arrester. Underneath, the space is divided by a thick piece of board. On one side are placed the jigger, the aerial induc- tance, high tension condenser, sliding inductance, spark gapand transformer; while, on the other, are the rotary converter and a small dynamo, the starter and field regulator being fitted on the side of the vehicle. Running along the truck, then on either side from door to bench, comes a locker 18 in. high by 18 in. deep. In this are stored the aerial, ong set of aerial poles, insulators, spanners, etc. These poles telescope into 5 ft. lengths, which can be neatly stowed away, when not in use. As these motor-trucks are designed both as traveling and fixed stations, it is necessary to equip them with two sets of Socket for heel of mast Steel mast for a fixed station A motor-truck, designed for both traveling and fixed stations, which carries two sets of aerials 608 604 Popular Science Monthly aerials. Hence the two sets of poles. The cog-wheel contrivance, operated by a telescopic type is the one used for mobile handle, at the foot of the mast. They give purposes. For the other, the set consists.of a stretch roughly of about 100 ft. and carry a 120-ft. steel mast, made up in 12 ft. four wires in parallel. Their power is derived from the truck Laying the earth mats from the motor bus used for a wireless. station sections. It is carried underneath the truck. When the latter set is to be erected, the pieces are first laid on the ground, fitted to- gether, and then raised to a perpendicular, in which position they are - held by eight wirestays. The aerial, in this case, engine which drives the dyn- amo, which in turn feeds the rotary converter. On the retreat from Mons, during those terrible early weeks of the war, these lor- ries did wonderful work. Then everything was in a state of chaos, while General French’s — ‘‘Contemptible Little Army,” as the Kaiser was pleased to term it, fight- - Ing every step of the way, was slowly retiring before the hordes of Prussians and Bavarians. * All cables were cut by the terrific — shelling, and fresh ones were laid only to be blown up the next minute. Then the trucks stood out, con- spicuous by their ef- ficiency. There, were just three of these motor sets in use at the time, divided among the moving infantry. Close behind the line, they kept upa constant stream of communica- tion between the fight- ers and General Head- quarters. consists of eight wires, One man in a motor-truck receiving And how those oper- arranged umbrella- fashion, which, at- tached to the truck of the mast, touch the ground at a distance of 20 ft. from its foot. The mobile type, on the other hand, has two sets of poles. The front pole is usually about 50 ft. high. When in position, it is fitted into a socket just alongside the driver, and is clamped to the top oi the wagon, so as to be perfectly rigid. The back mast, which is also about 50 ft. long, is likewise fixed in a socket. Protruding at an angle of about 25 deg., it is supported in its place by four wire stays. Both these poles, as I have said, are tele- scopic. They are opened out by a station stuck to his post for thirty- ators stuck to. their nine hours without sleep or rest posts! In the confu- The interior of a French motor-truck with a soldier- operator transmitting a message in field operations Popular Science Monthly "sion that prevailed, they were often per- ~ sonally forgotten, and it might be said _ that they forgot themselves. of one man who had the I know ‘phones on _ from seven o'clock one morning until ten _ the following night—thirty-nine hours with- out sleep or rest. Ee ee Ee eta ee a het fo And I know of another - Motor trucks are especially fitted and equipped with apparatus as wireless stations who stuck to his post with a splinter in his calf, causing him untold physical agony. A big shell had exploded at no great distance from his station and sent one of its _ pieces flying through the side of the truck. But these accidental tests of physical endurance were not the only ones the men had to contend with. There were other more permanent discomforts, too. To each truck, of course, were detailed two operators, one for receiving and_ trans- mitting; the other for logging, filing and distributing. Usually there were orderlies also on hand, four or five as a rule following on bicycles. If a message was to be delivered to any commanding officer within the truck’s sector, it was handed out to one of these. Just consider the position of those operators, penned up in that small space—very different from the accommoda- tions on shipboard or their comparatively luxurious quarters on land. Usually both men wore ‘phones to assist one another in receiving which, under the circumstances, was extremely difficult. Quiet, as you know, is_ considered essential for the work of a wireless man, but quiet was the last thing these men could + 605 obtain. To begin with, there was the incessant noise from the automobile en- gine; and there was the continual bumping of the truck over the uneven French pave- ment; and, last though not least, there was the occasional roar from nearby big guns. Tire Deterioration Caused by Im- proper Storage HEN exposed to the light and sun, especially to the hot summer sun, a rubber tire is likely to dry out, harden and become impaired in efficiency in conse- quence. The manufacturer wraps his tires in paper to protect them from the light when they are to be kept in stock at the factory. This also keeps them in shape. It is a good plan for the purchaser to leave the paper wrappet on extra tires, or, if the paper has been removed, to use the tire for a short time until the rubber be- comes soiled before storing it away. The pores will thus be filled by the thin coating . of dust, which will have a preservative effect. Tires should not be kept in a warm place for any great length of time, as light and heat will cause the sulphur to come out on the surface and make the rubber minutely porous. After gum checking or oxidation takes place, the nerve or fiber of the rubber is destroyed, with consequent bad effect upon the flexibility and dura- bility. A dark, dry room at a temperature of from 40 deg. to 50 deg. is most favorable for retarding chemical action in the rubber tread, side walls and the adhesive friction stock between the layers of fabric. When the car is laid up for the winter, or for other reasons is not used for several weeks, the stale air should be removed from the tires. Partially inflate with fresh air—enough to round out the tires and cover them with muslin or other ma- terial to protect them from the light. The car should be supported by blocks or jacks so that there will not be any weight on the tires. Paint for Use on Exterior Surfaces Should Be Left to Ripen AINT for exterior use should be allowed to stand after mixing for a day or two to ripen. It has been found that paint mixed and applied at once will not begin to give as good results as that given sufficient time to ripen after mixing. 606 A New Type of Acid-Proof Brush for Soldering Flux | HE use of non-corroding paste in soldering has, in many cases, done away with the disagree- Popular Science Montily _ good insulation from the motor shaft with. 4 extreme lightness. To make an arm embodying these fea- tures, proceed as follows: From a piece of fiber or bakelite of suitable length and 4% in. thick, cut a strip to able and dangerous acid brush. There are still a . few jobs, however, which require an acid flux for soldering. To those who have occasion to use sol- dering acid of any kind, the non-corrosive acid brushes shown in the il- lustration should prove serviceable. Both of the brushes shown employ a small piece of rubber sponge for the brush proper, the shape shown at A: The widest part should equal the diameter of the shaft-bushing, so as to fit flush. The dimensions will, of course, vary with the size of your ring; but - in any event the length of . this piece should be 4 in. less than the distance be- tween faces of opposite studs. Holes B and C are for fastening to the hub on the motor-shaft. Holes D and E, tap 2-56, while the handles are made as illustrated, one from an old rubber pen barrel and the other from a section of tubular porcelain insulator. The piece of sponge mentioned is forced into one end of the rubber or porcelain handle, as shown.—R. U. CLARK. Construction of a Rotating Arm for a Rotary Gap O those amateurs employing a rotary spark-gap of the type having the studs arranged in a ring about a revolving #22 GAGE SHEET __ ALUMINUM * ~~. ADJUSTABLE STUD SPARK GAP WITH LOCK NUT TERMINALS A light rotating arm constructed so that it is well insulated from the motor shaft arm, the construction of this arm often presents difficulty; for it must combine A discarded fountain pen case anda section of tubular por- celain insulator for brush handles are for screwing on the aluminum strip shown at F. This piece is 134 in. longer than the fiber. At a point 3¢ in. from each end bend the aluminum at right angles. This forms the sparking surface. Now, about 4 in. in from the bend on both ends, curve the strip as at G. Screw it down, as shown, to the fiber arm. After screwing on-the hub, mount it as shown at H. The proper adjustment of distance be-- tween electrodes is accomplished by chang- ing the stationary studs. This type of rotating arm is not only extremely light, allowing a quick start, but also has the advantage of cooling rapidly, owing to the exposed surface curving away from the fiber strip.. This curve should be at least I in. from the center for good insulation. Using Resistance in Field Wiring on an Automobile Dynamo ANY times the car owner is not en- tirely familiar with thelighting system and does the wrong thing when trouble occurs. Cars are equipped with a gener- ator that will carry about six 12 c. p., 8-volt, tungsten filament bulbs. Each bulb takes © about 114 amperes. If it is desired to use only a part of the bulbs at a time it is necessary to connect in the line a resistance equal to that used by the bulbs cut out of the circuit. This resistance should be put in the shunt field wiring to prevent the voltage from running too high. alone. ~ dent at once uniform for- Morse dots Sy ee ee ee ee See Or essential to its natural . operator cannot have already been published, in the August and September issues, out- q ey is two articles of this series which - lined the simplest ways to learn the Morse _ Code used in radio telegraphy and ex- _ plained a buzzer-telegraph line which could _ be used for code practice. of two. students in the manner indicated The cooperation makes it possible for both to advance far more quickly than could either one working By placing themselves at the’ _ opposite ends of an electrical communica- tion system (the buzzer-telegraph line) and by relying upon it for the interchange of _ messages and for correction of errors of transmission, both operators learn to de- pend upon their own efforts to signal correctly. It Wireless Work in Wartime. III. By John L. Hogan, Jr. ber of words in any given length of time. Dangeis of Student Practice Although the buzzer practice line has the advantages indicated above, there is a danger in having no sending to listen to except that of a companion student. Starting from the ground, with no tele- graphic experience, one is likely to make some mistakes even though the greatest care is used.. It is most difficult to form the complex characters like ‘‘Q’’ (dash-dash- - dot-dash) and “Y’’ (dash-dot-dash-dash) correctly, and a beginner is always likely to interject an extra dot-space or two. Con- sequently “Q’’ is made to sound like “M A”’ (dash-dash, space, dot-dash), and fy’ seems . becomes evi- LINE that clear, mation of the and dashes is real tele- graphing, since poor sending at once brings consequence of incorrect receiving. The greatest temptation of the novice telegrapher, viz., to send too fast, is quickly shown to ‘be productive of nothing but trouble; to send ‘co fast that the words run together, or so fast that incorrect Morse characters are formed, or so fast that the receiving oper- ator cannot put the words down easily and completely, is to show one of the clearest signs of incompetence. The experienced operator suits the speed of his sending to the particular conditions, and never trans- mits the words so fast that the receiving “copy” all of them. To adapt one’s gait to the man at the other end of the line, be it wire or wireless, is not only common courtesy but has been found by long experience to result in the ac- curate transmission of the greatest num- WIRE L + Diagram showing how three stations may be connected with the same line wire and other units may be added as desired | pai uNEWIRE §=©6 Very much : like ““N M.” This defect may be no- ticed after the word “YOU” is written out s “NMOUD” several times, _but the way the student usually _ cor- rects the fault is by increas- ing the space between ‘Y” and the next letters. This has the effect of setting off. the “NM” character, but is not a real cure, since the dash-dot-dash-dash of the letter ““Y’’ has not been smoothed out into perfect form. There are a large number of errors like these which creep into the sending of students, and, occasionally, even into that of experienced operators.. They are always dangerous, however, and often lead to serious misunderstandings. Listen to your own sending, and to that of your partner, and try to make sure that each dot, dash and space is formed and timed correctly. You can weed out these troubles your self by giving the Morse characters keen enough study; but the best plan is to have some experienced operator listen to your trans- mission and criticize it for you.. After you fir-3 £ a . FIG.8 607 608 have learned all the letters, and are able to call them to mind easily, try to get some trained wireless operator to call on you and send over your buzzer line. If you will send the alphabet through from A to Z several times, and follow it with the aug if B 7 ;: z J S C PIVOT a 000000 —O); FIGS SPRING A rotating disk with notches in its circum- ference to make the dots, dashes and spaces . Classical sentence, ‘“‘The quick. brown fox jumps over the lazy dog” (whicn contains every letter of the alphabet), he will soon be able to judge wherein your sending is in need of improvement, and to correct you. Be sure to pay strict attention to his sugges- tions, for they will probably be valuable to you. - After your sending has been passed on by a seasoned operator, try to have him send for you a little while. Ask him to send so slowly that you can get every letter, and pay close attention to the smoothness with which he forms the dot and dash combina- tions. at the station at one end of your line, and go to the other end yourself. By exchanging a few messages with him, and _ listening sharply to his style of Morse sending, as well as by having him note the imperfec- tions in your sending, you can do a great deal toward perfecting yourself in the art of telegraphing. Three-Station Lines Occasionally it is possible to run the buzzer telegraph .line by the home of a wireless operator, and to install a third station in his house. If he is willing to help you out, he will send from a newspaper for half an hour or so each evening, and then let you send to him for ten or fifteen minutes. exceedingly valuable, if it can be arranged. Sometimes half 'a dozen students wish. to get on the same buzzer-telegraph wire and to practice together. Fig. 8 shows how Popular Science Monthly If you can, have him take the key » This sort of practice will be - three stations may be connected with the same line,wire, and identical station-units may be added almost without limit. Pressing the key K at any one of them will operate its buzzer Z, by reason of closing the circuit from the battery B through the buzzer magnet windings, and the signal- tone of the buzzer will be reproduced in the telephones 7 at all of the stations. It is only necessary to keep the insulation of the. line wire L L L fairly good, so as to prevent leakage, and to make a good connection to earth through a scraped water, gas or steam pipe at each of the points marked F in the diagram Fig. 8. The higher the ‘resistance of the telephones, up to several thousand ohms, and the more powerful the buzzers and batteries, the better the line will work when a comparatively large num- ber of stations are added to it. If the signals in any of the telephones are found to be too loud, their terminals may be shunted by a resistance of fifty or a hundred ohms or thereabouts (the best amount being found by trial), as shown in Fig. 5 (last month’s article). It is not always easy or even possible to get a wireless operator to visit your home and try out your buzzer line; if you find this difficult, it is a good plan to call at some local telegraph office and to try to pick up a few pointers from the operators there. Although the line telegraphers in: the United States use the American Morse code, which differs as to some of its charac- ters from the International Morse used in wireless, the two systems have much in common and a few words of criticism from a skilled line operator will often be of inestimable value to the student. Copying Perfect Signals Such a plan, however, does not give the Another type of automatic sender in which a tape is used having holes in it for the letters student any opportunity to listen to and ~ copy perfectly formed Morse characters at gradually increasing speeds. The two- Popular Science Monthly student plan of learning will of course develop both the speed and reliability needed, a little at a time, but for the best results there should be some way to check and eliminate possible errors in sending which may pass by both students quite unobserved. The best way to take care of. * this difficulty is by the cooperation of a LINE WIRE 609 of the alphabet singly and in regular order, and also in mixed order. This last named: arrangement is especially desirable for practice, since it is almost impossible to anticipate the letters about to be sent, and the student is forced to listen closely and on quickly in writing the letters as they occur in what LINEWIRE == $= amounts to a long skilled operator, as explained above. If no such help can be secured, the next best plan is to use R an automatic sender of some sort. Such an auto- transmitter, driven by clock- work or by a small electric motor, can be used in self- cipher word. Several forms of the disk sender are made, under T the trade name of “‘Omni- graph,” in which the disks are rotated either by hand or by clockwork. The automatically driven type is by far the best for seri- instruction or by a group of students. Several types are available, but the two most employed use metal disks or paper tapes already pre- pared and carrying various combinations of words and letters in common usage. The Disk Sender FIG. “Se automatic The operation of the metal disk type is © indicated in Fig. 9, where the disk itself is shown rotating in the direction of the arrow and having notches cut around its circum- ference to correspond with dots, dashes and spaces. - As the disk re- volves, the point on the 1 spring arm P moves back ; and forth along the irregu- 4 lar teeth, and the contacts 5 A and B are brought to- 6 gether and separated to 7 form dots and dashes. 6 When the contacts are 9 pressed together the bat- ° tery circuit from the dry Aweine cells D through the buzzer _ yterrogarion ra is closed by way of the PARENTHESIS pivot J, spring Sand bind- quotation ing post C, and the buzzer __pouste asi sounds. A short tooth on the disk produces a dot signal, and a long tooth a dash. Thus the notches shown in Fig. 9 would produce dot-dash, space, dash-dot-dot-dot, or the letters “‘A”’ and ‘‘B”’ separated by a space. The metal signal-disks are made up in great variety, and are interchangeable so as to form complete messagés. For beginning of practice there are disks giving the letters FIG 2 Diagram of connections for an sender The numerals and the most used punctuation marks in telegraphy ous work, since its speed may easily be adjusted to almost any rate which oc- curs in telegraphy, and, once started, the instru- ment may be put com- pletely out of mind and full attention given to writing out the letters and words pro- os tee Se in a line duced by the buzzer. The Paper Tape Transmitter Another sort. of automatic. sender is shown in Fig. 10, in which a cut paper tape passes between a spring contact and a metal roller. The sketch shows how the “‘slip’’ is threaded over a guide rol- ler Gand between the two driving rollers E and F which turn in the direc- tions indicated by the ar- rows. The spring contact H bears down on the paper, and, when a _ hole in the tape comes under it, makes contact with the metal roller F. This closes the battery circuit -from the cells B through the buzzer Z, and the buzzer reproduces the dots and dashes cut in the paper strip. On the left is shown the letter ‘‘R’’ (dot-dash-dot) and on the right the letters ‘‘A”’ (dot-dash) and “T’’ (dot-dot). An automatic transmitter of this general sort, in which the tapes are cut to give various word and letter combina- tions, is sold under the name of the ‘‘Audi- ble Alphabet. ” The instrument is driven Tit 610 by turning a small crank by hand, but it is not difficult to gear a small electric motor to operate it and thus to afford true automatic operation. Any sort of automatic transmitter can be made very helpful in learning the code. The apparatus is not very expensive, and if five or six students combine to purchase one together the cost to each individual becomes extremely low when compared with the benefits secured from having a tireless sender of perfect Continental Morse signals which will give practice as long as it is wanted. Fig. 11 shows how to connect the automatic sender at one of the stations of a multiple-station buzzer-telegraph line. The balance of the stations are wired in ac- ‘cordance with Fig. 8. The automatic sending station of Fig. 11 may be chosen to be somewhere near the middle of the tele- graph line, so as to give about equal strength signals at both ends; the line wire extending to the other instruments is in- dicated by the broken line at the top of the figure. The telephones T are shown shunted by the signal-intensity regulating resistance R, and connected between the line wire and the vibrator post contact of the buzzer Z. The two outer terminals of the buzzer are connected in series with the battery B, a single-pole double-throw switch S, and either the hand-sending key K or the auto- matic transmitter A. The armature post of the buzzer is connected with ground at E. When the switch S is in position J the hand key is connected, and signals may be trans- mitted in the usual way. When the switch arm is in position 2, the key is cut out and the automatic transmitter placed in circuit. The signals which it sends out are trans- mitted both up and down the line, and may be copied simultaneously by all the students at their respective home stations. Morse Practice on the Buzzer Line By arranging a definite time schedule for running the automatic sender, it is possible to work out a scheme of daily Morse practice at gradually increased speeds, until finally all the learners are able to write down messages at a speed of from twenty to twenty-five five-letter words per minute. To make the practice comprehen- sive it is necessary to arrange for periods of sending practice for each of the stations, in which one student sends messages or press notes from the newspapers and all the others copy his signals. The messages as copied by each one should be carefully Popular Science Monthly compared with the original as it was sent. out; errors in receiving can be located by reason of their appearing on only one of the copies, while errors in transmitting should show up in all of the copies. Practice of © this sort, varied by the exchange of mes- sages between various pairs of stations on the line, will give the most valuable training © which it is possible to secure outside of actual radio telegraphy. In the first article the Morse symbols corresponding to the twenty-six letters of the English alphabet were given. Fig. 12 shows the numerals and the more usual punctuation marks. These should all be memorized and used in the message practice. Entire familiarity with the code as thus completed will come with the daily sending of dispatches, and a few months of this work should make any apt student a fairly. skilful telegrapher. In the next article the formal methods of sending messages with full preambles, ac- cording to the International Radiotelegraph Convention, will be explained and -illus- trated, and the problems of reading messages and signals through interference from other radio stations and from ‘‘static’’ or atmospheric electrical disturbances will be discussed. (To be continued) The Underwriter’s Knot for Flexible Cords LEXIBLE cords used to suspend a lamp should be arranged so that there is no stress or strain coming on the binding posts or con- necting screws. To i provide a suitable A knot tied in line in suchaway holding astotakethestrainfromafixture Means, knotsshould be tied in the cord to make them take all the weight of the socket and fixture from the ends of the wire. The successive steps in tying the knot are shown in the illus- tration. While these knots may appear to be of no use they are absolutely necessary, not only to relieve the strain, but to fulfill the requirements of the underwriters’ code for safety in insurance. Making a Practical Vacuum Cleaner I.—Details in the construction of the universal motor By L. E. Swindell piece of apparatus to construct, and it will do the work equally as well as a standard make. However, building it yourself will not reduce the cost to any appreciable degree. The only thing gained will be the satisfaction of saying “I made it myself.” The essential parts are a high, speed electric motor to drive the centrif- ugal fan, and a suitable case with a shoe or nozzle to collect the dust from the floor and discharge it into a cloth bag which * retains the dust and releases the air. The following materials are necessary in the construction of the vacuum cleaner. So machine described is not a difficult MATERIALS FOR THE Motor gO pieces transformer iron 0.015 in. thick, 34% in. sq. go pieces transformer iron 0.015 in. thick, 2 in. sq. 1 shaft, cold rolled steel 34 in. diameter and 7\% in. long 2 bolts 4% in. diameter and 4 in. long, threaded 1% in. on each end 2 hardwood blocks 34 by 3% by 1 in. I piece iron % by 7 by \ in. 2 iron washers 11% in. diameter, 3%-in. hole 2 8-32 brass screws I in. long 2 pieces brass tubing 14 by \% by % in. (inside measure) 4 par ganic 54 in. square, -in. hole, 1/16 in. - thic ‘ I commutator, 22 segments ¥% lb. No. 26 gage enameled magnet wire \% lb. No. 29 gage enameled magnet wire. MATERIALS FOR THE SHOE Enough sheet iron 1-16 in. thick 15 soft iron rivets \% by % in. 6 8-32 brass screws 4 in. long 1 cylinder of brass 1% in. long by % in. diameter Y-in. hole I piece of fiber 1 in. thick 2 by 2 in. square 2 pieces iron % by \% by 14 in. 1 hardwood handle 3) ft. long, 1% in. diameter If you can secure a fan motor of suitable size you will save yourself considerable time and labor. For the benefit of those who cannot obtain a motor, or who wish _to build their own, the necessary directions will be given for the construction. If a motor cannot be procured some machine work on a lathe and drill-press must be done. » of 34%in. The Motor The motor is of the alternating current series type, wound for use on 110-volt circuits. It may also be used on direct current. The field for use on direct current could be of solid iron, but for alternating current it must be laminated because of eddy-currents and excessive heating. The dimensions of the field magnet are given in Fig. 1. A stack of transformer iron 3% in. square and 1) in. thick should be clamped between two hardwood blocks by means of the two 4-in. bolts as shown in Fig. 2. Now proceed to turn the mass of iron and wooden blocks to a diameter Use a high speed and a very sharp tool, cutting toward the lathe chuck. The center should be turned out to a diameter of 1 9/16in. The wooden blocks should now be removed and the pole pieces machined. This is the most difficult for the amateur to do. If the directions are followed and a little patience used, a neat job will result. If a row of holes are drilled between the pole pieces just inside the 214 in. diameter, the remaining ma- terial can be easily removed with a sharp cold chisel and finished with a round file, The laminae can now be taken apart and each varnished with black insulating var- nish. When dry, reassemble the laminze and proceed to wind the field. Each pole is surrounded by a coil of 200 turns of No. 26-gage enameled magnet wire thoroughly insulated from the iron by empire cloth. The wire should be wound on by hand so that it will occupy as little space as possible. The field poles should be thoroughly insulated by means of strips of empire cloth wound tightly around them and then varnished. The leads should be brought out and the coils connected in series; i.e., the end of one coil should be connected with the beginning of the other. The two free ends should be brought out and protected from injury, and the finished field set aside while the armature is built. The armature is of the usual drum type, with eleven drilled slots to receive the windings. The shaft is of cold rolled steel, 611 612 Popular Science Monthly INSULATING WASHERS | SLOTS COMM. K SEGMENTS COMPLETE MOTOR MOTOR CONN. B' ee FIG. 9 Entire details of all the parts necessary in the construction of a universal motor that is especially adapted to drive a fan on the ordinary vacuum cleaner used for household purposes 7/16 in. in diameter, rough, to be turned as shown in Fig. 3. The threads may be cut in the lathe at the same time that the shaft is being turned. Now bore a 3%-in. hole through the center of the stack of 90 2 by 2-in. iron and then varnish the plates. When dry slip them on the shaft and clamp them between the two iron washers. Do not tighten the nuts too much or stripped threads will result. Now proceed to turn the armature to a diameter of 114 in. Be very careful not to feed the lathe tool too fast or it will cause the plates to turn on the shaft. Now lay out the eleven slots as shown in Fig. 4. The drilling should be done in a drill-press and the armature set in a jig so that the shaft will be parallel to the drill. Great care should be used to get the slots absolutely parallel to the shaft and accurately spaced. With a hack saw cut through the 1/16 in. of metal on the diameter of the laminae and smooth up with a small file. The shaft can now be finished to 44 in. in diameter. This should not be .done earlier because it would twist out of shape Popular Science Monthly while the laminae are being turned. The armature is now ready to receive its wind- ing. Referring to Fig. 6, the method of wiring can be easily understood. There are two coils per slot, each having a span of six slots. The winding consists of twenty-two coils, each of which is composed of 20 ft. of No. 29-gage enameled wire. Now measure eleven 40-ft. lengths of wire and in the middle of each twist a loop about 1 in. long. Before beginning to wind the armature the slots must be lined with empire cloth. Cut from the cloth eleven strips 154 in. long and I in. wide and line each slot, using a little glue to hold them in place. Beginning with slot No. 1, skip to slot No. 6 and wind until you come to the loop, which should be brought out on the side of the commutator. The next coil is wound in the same manner in slots No. 2 and No. 7, etc. Now to the end of the first coil (not the loop) twist the beginning of - the second coil. It is well to tie a knot in the end of each coil for identification when the commutator connections are made. When the winding is complete it should be tested for grounds and breaks, etc. This may be easily accomplished by means of an incandescent lamp in series and the lighting circuit. If the coils pass the test, strips of fiber 1/16 in. thick, 5/32 in. wide, and 1¥% in. long should be inserted -in the slots above the wire to prevent the - wire from being thrown out by centrifugal force. Now give the armature two coats of insulating varnish and set aside to dry. We will now need a commutator. The writer has found by experience that this had best be purchased. It may be ob- tained from an electrical repair or supply shop for a small sum. It should have 22 segments and be of the dimensions given in Fig. 5 and fit snugly on the shaft. To connect the armature coils with the com- mutator proceed as follows: With a fine- toothed hack saw cut a nick about 1/16 in. deep in the end of each commutator bar on the side nearest the coils. Now solder the loops to alternate bars, keeping them in their proper order. Be sure to use a non-corrosive soldering flux. One element of the winding is in heavy lines, Fig. 6, clearly showing the proper connection of the loop to the commutator segment be- tween the bars connected with the begin- ning and end of the coil. When the connections are complete, center the arma- ture in a lathe and take a very light cut 613 off the commutator, removing. the super- fluous solder. On the opposite end of the— shaft is a brass thrust sleeve, which should be a snug fit and be pressed on the shaft. The top bearing and brush holder are shown in Fig. 7. The bearings are turned from a piece of brass or phosphor bronze rod. Both bearings are of the same dimen- sions. The brushes are of 14-in. square carbon, held in two pieces of square brass tubing. The tubing is sweated to an 8-32 brass screw I in. long and set at such an angle that the brush is at right angles to the commutator. Each brush holder is insulated from the bearing bracket by two fiber washers, one on each side of the bracket as shown in Fig. 7. Now clamp the bearing bracket, field laminae, and hard wood ring, Fig. 8, rigidly together by means of the two \-in. bolts, which should be cut off to 2% in. The lower bearing is to be set in the center of the top of the fan case and secured by means of two small brass screws. A small brass oil tube about 1% in. long is soldered to the oil hole in the bearing and brought out through a hole in the hardwood ring. On the underside of the bearing is a dust cap, which consists of a felt washer I in. in diameter covered by a cap about 1) in. in diameter. The - top of a small paper fastener will serve the purpose well. The dust cap is on the underside of the top of the fan case. The connections are shown in Fig. The motor is now complete and should be tested out. If it runs in an anti-clock- wise direction the field leads must be re- versed so that the armature will rotate in a clockwise direction. (To be continued) Connecting a Spotlight in an Automobile Dynamo Circuit SPOTLIGHT was wanted on an auto- mobile in which the lights were on a series circuit. As the spotlight was only to be used occasionally the method of wiring was as follows: A single switch was mounted on the dash and a wire connected with it from the left hand termi- nal on the back of the ammeter. Another wire from the switch was connected with the spot lamp and grounded to the other terminal of the spot lamp. If a spot lamp is procured with a switch on it, it is only necessary to connect a wire from the am- meter to the lamp and ground the lamp. 614 Blackboard an Adjunct to the Amateur’s Shop BLACKBOARD is a valuable adjunct to the amateur’s shop. ©ne may easily be made of a sheet of cardboard painted with a mixture of lampblack and gasoline and then tacked in a convenient place on the shop wall with crayon box nearby.—HaAroLtp W. OFFIUs. © A Grid Placed in the Wings of an Airplane N_ wireless telegraph work on airplanes there is often difficulty encountered in obtaining sufficient metal work to serve in a balancing capacity. In the construction the bracing wires of the wings are so connected that they provide a good path throughout the whole length of the wing, through which they are led to the wireless transmitter. air friction, additional wires are mounted inside the wing frames which are connected with the bracing wires. These wires are supported by lashings through the slots in SF | WW Cn) AW AAA Wires making the grid for an aerial are placed in the frame of an airplane wing the ribs. As these wires form a grid they are placed parallel and are of equal lengths. In the illustration the bracing wires are shown at A. They may be either bare or insulated. At B is a modification of a grid, the wires being supported by lashings through slots in the ribs. To prevent. Popular Science Monthly A Simple and Interesting Thermo- Magnetic Motor VERY simple thermo-magnetic motor which utilizes the principle that heat- ing a piece of metal weakens its magnetic properties, can be easily built. The rim of Cork center The wheel rim is heated by a lamp to reduce the mag- netic properties of the parts close to the magnet Candle Copper spok the wheel that revolves is made of a piece of heavy iron wire, which is held together with copper spokes fitted in a cork A. Through the center of this cork a large pin is placed,. about which the wheel rotates. The lower end of the pin is stuck into another cork B, which is glued to the base. A strong horseshoe magnet is then sup- ported on a block of wood near the rim of the wheel as shown. A small alcohol lamp, is then placed under the rim of the wheel, care being taken that it is not placed too near the magnet poles, as it would heat them and destroy a large part of the magnetism contained in them. As soon as the portion of the wheel directly over the lamp becomes heated, the wheel will begin to turn, the heated portion revolving away from the magnet. This is because the heated portion has lost some of its ability to be attracted by the magnet, therefore it moves or is pushed away by the cool metal— ALEXANDER V. BOLLERER. An Undercoating for Copper to Hold Paint OPPER does not hold paint well, hence it must be treated with some substance that will take the paint, or left to weather a year or more. A _ good primer is boiled linseed oil, to which add a little Japan gold size. Apply one coat and let it stand about one week, then apply the paint over it. me Warming Army Tents With Improvised Stoves EFORE the United States Government issued tent stoves to the Guardsmen on the Border, there were many improvised stoves or heaters to be seen in the various tents. The stove shown in the upper left corner of the illustration is the type known as the Sibley tent stove, which is the one issued by the Government to keep the boys warm. There were some stoves made along these lines and in use before the Federal authorities TOVE PIPE MA considered it OF SMALL CANS cold enough to issue them to the men. These stoves were roughly shaped from sheet iron. and riveted to- gether. An- other popular stove, which is made from a 5- gal. kerosene can or a 25-lb. coffee can, is shown in the corner of the tent. Two small holes about Y in. in diameter, are cut near the bottom for air vents and a hole about 4 by 8 or 6 by 6 in. is cut in the front to allow the insertion of fuel, another hole being cut to carry off the smoke and allow for perfect draft. The fire is regulated by placing a piece of tin over the fuel or fire opening and another over the air vents in the bottom. When starting the fire the air vents are left open and the fire opening is kept covered. When the fire gets well started it may be checked by opening the slide over the fire opening or removing it altogether, or the vents at the bottom may be closed and the slide on the fire opening left closed or partially open. Three types of roughly improvised stoves for heating the tents of the guardsmen on the Mexican border FOR PRACTICAL », WORKERS A very simple brick stove is shown in the upper right corner of the illustration. The bricks were laid up with mud for mortar, the whole thing requiring less than 50 bricks. The stove served as a cooker as well as a heater, for food could be readily heated on top of the tin or iron cover. The worst problem of all was to get the required amount of stovepipe, but in several instances this difficulty was overcome by using empty vegetable cans. These are plentiful about a camp. The only trouble with this style of stovepipe lies in the fact that the cans act on the same principle as a muffler on on a gasoline engine and thereby fail to accomplish the desired results, as the smoke is held in check and a slow smoky fire results.— GEORGE M. PETERSEN. a Stropping a Razor on the Fleshy Part of the Hand gf Ge finest strop for a razor is the fleshy part of your hand below the little finger. For eight years I have used no other for razor blades. If it is a safety razor blade grasp it between the thumb and first finger of the right hand and strike finger nail and blade at the same time on the fleshy part of the left hand. If you will do it slowly at first the mo- tion becomes automatic. I put a little vaseline on the cutting edge. This keeps the. blades constantly in first class con- dition.— JOHN W. SHANK. 615 616 Making a Campfire Tent out of a Pack Cloth HE campfire tent shown in the illustra- tions is most comfortable to livein. It is of the open front type and is always well ventilated. With the front flap raised as an awning, the heat from the fire is reflected 9.= <— 10>} Dimensions of the cloth for making an open front campfire tent equipped with an awning inside, where it is most welcome on a cool night. Fhis tent may be made of the simple lean-to type, or with the front flap. The model with the awning is a nice roomy tent for two or three persons. All models are easily made from a rectangular piece. of material, and merely folded on the dotted lines. This makes it unnecessary to cut the material up, and when not in use the tent is folded out flat to serve as a tarpaulin, an apron to cover the canoe, or as a pack cloth to wrap around the blankets and other camp duffle. The two end _ segments, within the dotted lines, are folded in to serve as a sod cloth, and an additional strip of cloth may be sewed to the back wall to serve the same purpose. This is desirable, because it keeps out the wind and rain and prevents insects from entering. As lightness is desirable, a heavy grade of unbleached cotton cloth is the best choice. If a heavier material is wanted, use regula- tion duck in 6, 8 or 10-ounce weights. Common khaki fabric is good, and stout enough for ordinary use. The breadths of cloth are sewed together by lapping one edge over the other about 34-in. and double stitching the seams. This can be done on the sewing machine. A 1-in. hem should be ‘run around the edges. Popular Science Monthly The eyelets are sewed in by making a small hole at the proper place, and placing a brass ring or grommet on each side of the hole. Sew over and over with an over- casting stitch, using waxed seine twine or ordinary string. Every tent should be waterproofed. The following method is one of the best: In 4 gal. of boiling water (rain water) dissolve 4 lb. of common powdered alum. In a separate pail, dissolve 4% lb. lead acetate (sugar of lead) in 4 gal. water. Pour the alum solution in a clean tub, and add the lead solution. Let this stand for several hours, then pour off the clear liquid and work the canvas thoroughly in it, so that every part of the cloth is well saturated. To make the cloth absolutely waterproof, it is necessary to fix the acetate of alum in the fibers of the cloth, and this cannot be done unless soft rain water is used. Finish by lightly rinsing in clear water to remove the dust of sulphate, and hang up to dry. An ordinary coat or sweater can be water- proofed in the same way, and cloth thus treated is fireproof also. Sugar of lead is a poison, but only when taken internally. If the tent is wanted of a brown or forest-green color, the cloth may be easily dyed with Diamond Dye or other household dye. This should be done before water- proofing and after the tent is madeup. The tent may be staked with the usual ridge and side poles, with the crotched ‘sticks cut in the woods, or suspended along the ridge with a rope, hung between two trees.—STILLMAN TAYLOR. Preserving Flowers in Natural Colors with Wax © T is not generally known that preserving flowers in wax is one of the easiest of tasks. Ordinary candles may be used. To prepare the wax, it is only necessary to cut the candles into chunks, being careful to remove the wicks. The wax is then melted in a saucepan over a flame, after which it is ready to receive the flowers. Each flower should be dry on the surface when treated; there should be no rain or dew- drops on the petals. Take the blossoms separately and dip them for a moment or so into the liquid wax, constantly moving them about. Immerse the blossoms com- pletely and also an inch or so of the stem. Then take them out and hold until dry. Do not lay them on a table or flat surface until they are dry, as this will crush them. ] tion book furnished by the car maker. in tinkering around their cars and keeping them in repair would like to 4 Vn 3 automobile owners who delight _reline the vehicle brakes were they sure - they could do it properly and not jeopardize their lives through poor workmanship. _ The drawings shown indicate the various _ steps necessary in properly relining a brake. _ First, jack up the rear axle of the car and remove the rear wheels as per the instruc- At Cut here f | rs — of Fig. 5: Cutting the length of a new brake lining, marking the places for the rivets, punching and counter- sinking the holes, placing the rivets, hammering them to a head and applying the band the same time disconnect the toggles and remove the brake clevis pin, the adjustment. screw and the various coil springs attached to the brake-band. Then remove the band, keeping in mind the top and bottom of the assembly. Clean all the parts thoroughly with gasoline and remove all the old grease around the brake dust-guard and the axle- ;: stub. Buy the new lining in one piece but do not attempt to cut it until the brake has been removed. To obtain the correct length, measure around the outside of the external brake-band with a tape, allowing an overlap of about in. so that the lining is not short at the band opening. Deduct How to Reline Your Automobile Brakes , An easy method of inserting new lining in a brake drum By Joseph Brinker about 14 in. from the external measure- ment to get the cutting length of the lining sy one internal brake. This is shown in ig. I. Then put the band in a vise as shown in Fig. 2 and chisel off the heads of the old rivets. In marking the new lining for the rivet holes, lay the wheel on the bench or floor with its hub side down. Put the lining and band in place as shown in Fig. 3 and wire the band in place. Then with a Fig.7 soapstone stick or pencil, mark the position of the holes in the new lining, using the holes in the band asa template. Then cut the holes with a leather punch similar to that shown in Fig. 4. Place the band and lining together in a vise or on a bench as shown in Fig. 5, hold- ing the lining in place by several small bolts inserted through corresponding holes. A wood countersinking bit and a brace will serve for countersinking the holes in the lining so that the rivet heads will be below the lining surface. . After that is done insert a rivet through a corresponding hole in band and brake and place the countersunk head of the rivet on nwaa~ 618 top of a bolt fastened in a vise as shown in Fig. 6. Insert a short piece of pipe over the free end of the rivet and tap the top of the pipe with a hammer to draw the rivet head and lining tightly in place. See that the end of the rivet extends about 3/16 in. through the band. Then rivet over the heads with light, sharp blows of a hammer. The method of doing this for the external brake is shown in Fig. 6 and for the in- ternal type in Fig. 7. Care should be taken in marking off the lining holes or, in case of the external brake, the lining may tend to cut corners as shown in Fig. 8. This may be avoided by leaving the holding-in bolts in place in lining and band until the other holes are filled with rivets. A Cord Cutter Made From a Safety Razor Blade HIS cord cutter consists of a discarded safety razor blade and a block of wood. _ If the cutter is to be used on the counter edge the block of wood should be consider- ably thicker than the coun- ter top. The lower edge of the block is placed flush with the under- side of the coun- ter allowing the extra thickness to project above the upper surface, which is notched in the center and cut slanting ‘toward both ends. It is then fastened with two wood screws run through the holes in the razor blade. This manner of fastening allows a small portion of the blade to extend in the notch where the cord will strike it upon being drawn in the open- ing.—THomas DEAN. ——— _— eas Screws pass through block and razor blade Discarded razor blade used as a cord cutter Electric Lamp Attached to a Spoon for Tongue Depressor HEN it becomes necessary to examine the throat of a child, or to remove a lodged fishbone or button, a spoon is the first thing sought for to depress the tongue in order to make the examination. A good light is also necessary. To furnish one for the purpose, a small electric light may be attached to the back of the spoon. This lighted spoon is not difficult to arrange. It requires only an ordinary spoon, a small two-volt lamp, a dry cell, a few inches of enameled wire—about Popular Science Monthly 18 gage—one insulated and one uninsulated — binding post and 3 or 4 ft. of flexible cord. Scrape enough enamel from the ends — of the wire to allow for soldering to the lamp and attaching to the binding post. — 7 Attach the posts on the end of the spoon handle. Solder the base of the lamp to the Terminal soldered to spoon uninsulated A small electric globe fastened to an ordi- nary table spoon for examining the throat spoon bowl and the end of the enameled wire to the center button of the lamp. Connect wire attached to the center button on lamp to the insulated binding post. Enamel the base or back part of the lamp so that the light will be reflected into the throat and not into the operator’s eyes. Attach the flexible cord to a battery and to the binding posts, and the spoon is ready for use. If carefully made, this will prove to be an invaluable addition to the ‘first aid’’ equipment of the medicine cabinet. The spoon with the attachment can be sterilized in hot water.—E. A. WARNER. Temporary Repair on a Broken Lubricator Filling Glass STEAM shovel located at a great distance from a repair shop had a broken lubricator filling glass. There were no extra ones on hand. The sketch illustrates how a small piece of wood was whittled and substituted for the glass. Though this did not register the use and supply of oil in the lubricator, it plugged the openings left by the broken glass _satisfac- nicely until new glasses arrived .several days later. The wood should be cut as round as the glass to make a close joint at each end in the fittings. The nuts should be made secure.—F. W. BENTLEY. ~ A wood plug sub- stitute for glass Bo a torily and held very C* INCE the publication of the article in ~.) the September issue describing the a method of laying out elbow patterns, many inquiries have been received asking _ for the method of finding the miter lines and laying out the patterns for elbows . having any number of pieces. The author and publishers are very glad to receive this ‘indication of interest in the series and are especially glad that it is in the scientific side of the work. They will welcome further suggestions. _ Almost every pattern drafter has his _ own pet way of laying out the many pieced i elbows, and various ingenious charts, dials, _ disks, tables, etc., have been worked out and placed on sale. However different these may appear, one from the other, _ they are all based on the same fundamental _ metiods and principles. In all elbows of more than two pieces, _ the two end sections should be one-half _ the size of the other sections. Note the end sections of the drawings showing the elbows in A. -It is only necessary to de- _ velop the pattern of the bottom end section. This can be used for a pattern for all of the ' other sections, as will be shown later in _ the description. It is necessary to lay a out the drawing for the complete elbow _ with all the miter lines to get the correct _ miter line of the end section. This extra - work can be avoided if you will make one of the miter lines charts as shown and _ described later in the article. _ It is always understood when speaking _ of elbows that we are referring to elbows of 90 deg. In the drawing A we have _ two elbows, one made of three pieces and the other of five, but both are 90 deg. For an explanation of this entire problem we will take a four-piece elbow. Draw , two arcs, as shown by the dotted lines C-D and #-F in drawing B. We already know _ that the two end sections are to be one- half size of the center sections. As there _ are four pieces in the elbow the two center - sections will be twice the size of the two ends, as shown. If we take the size of one end section as a unit we find that _ Sheet Metal Working Simply Explained V.—Method of finding the miter lines and laying out the pattern for ninety-degree elbows of any number of pieces By Arthur F, Payne Director of Vocational Education it is repeated six times in the entire elbow. Then we must divide the arcs C-D and E-F into six equal parts. Another way of stating this is: There are four sections in this elbow; there are two end sections and two center sections. Count one for each of the end sections (1+1=2). Add two for each of the center sections (2+2=4), This rule making a total of six units. Pattern for Pattern for Elbows of more than two pieces and the way to lay out a pattern for cutting out the different sections applies to all 90 deg. elbows of any size and any number of pieces. The method of developing the pattern for the elbow. in B is shown and has already been described in the June and September articles. It will save considerable time when laying out these elbow patterns in practical work if you will make from a piece of heavy tin one of the miter charts as shown in the drawing. This chart will give you the miter line of the bottom end section of the elbow and all you need to do is to develop the pattern for the pipe of the diameter wanted. To make this chart, cut out of heavy tin a triangle that is 12 in. on two sides, as shown in the drawing, then with a protractor lay off the angles as indicated 619 620 in the drawing and table. -A good pro- tractor can be purchased very reasonably. Cut out the pieces as shown on the right edge of the chart. To use this chart, lay it flat on the Popular Science Monthly An Inexpensive Cesspool Made of a Barrel and Cask A SERVICEABLE cement cesspool can be constructed in the following manner at a cost of about three 2Pieces 45 - se eet Sea yore as" sh a : degrees dollars. The essentials are sPlecesnlt a large crockery cask that degrees stands about 4 ft. high, Ease half of a lime cask, three or 4Pieces 15 deaiees rf four bags of cement and 3-22), a plenty of clean sand and epaces | Lea ; ==S======= loose stone. Dig a hole 9 [55S 7 == about 8 ft. deep and 18 in. ase Loy. | larger in diameter than the = 0-59 en extreme diameter of the ———— ra, esas eae Pee crockery cask. Fill this. : Cs Cums >> — Popular Science Monthly 623 until the two inside edges of the images are parallel to the thin edge of the wedge. When the one image-edge is in line with the wedge’s thin edge, the image-edgé in the other mirror should also be in line with it. The image positions should appear as } hi iy. ——_ 4 A range-finder suitable for the woodsman or camper to aid in locating landmarks and computing their distances or the width of rivers and valleys. _ Any boy can make his own range finder from materials that might otherwise go to the scrap-heap. The essential feature of the device is shown at A. This is cut from a wedge- shaped piece of wood 2 in. long, 114 in. wide, and 3/32 in. thick. From the thick end it is tapered to a very thin edge at the other end. Cut away a piece %-in. wide extending from the thin end to 4% the way toward the thick end. Two strips 34 in. long and & in. wide are cut from a good quality of thin mirror, and they are fastened to the prepared wedge of wood with bits of beeswax. Both mirrors face toward the front as shown. Lay the mounted mirrors face-up on the floor, slipping something under one side of the wedge so that the lower mirror will be level. Cut from stiff white paper a piece exactly 2 in. square, then hold it in a horizontal position just 20 in. above the thin edge of the wood wedge, peering down at the mirrors through a hole punched in the center of the paper square. Two images of the card will be seen, one in each mirror. Slip the card along, keeping it 20 in. from the wedge-edge, rotating it | WEDGE >i (—— Z)._ | ZOD | It is made of odds and ends of scrap indicated by the shaded portions in the mirrors. If, however, the images overlap, then the mirror strips are too nearly parallel; if they do not touch, then the angle between the mirrors is too great. In either case the angle between the mirrors must be corrected by pressing the mirror strips firmly against their beeswax pellets ‘STRIP A wedge shaped piece of wood with thin mir- rors attached is fastened to a _ baseboard until they fulfill the alinement test at the 20-in. distance. A little patience is needed. When successful take a stick of red sealing wax and a hot nail and wax the edges of the 624 mirror strips sncaly to the wood wedge, being very careful not to disturb the adjust- ment of the strips. Make.-the sealing wax very hot with the nail so that it will not break loose. The other part of the work is easy. Cut from a board a piece measuring 8 in. long, 2% in. wide and % in. thick, and nail a wood strip of %-in. square cross-section across one end at a 45 deg. slant. Glue the wood wedge against this strip so that the mirrors stand as in B, facing away from the supporting strip. To complete the range-finder cut a piece of tin 134 in. square. Cut into it a slit I in. long and 1/64 in. wide and tack the tin against the end of the baseboard so that the slit and the thin edge of the wood wedge are parallel and the same distance from the side edge of the board. The distance of an object, C, may be determined as illustrated. Turn the left cheek toward the distant object and, look- ing straight ahead, hold the slit of the range-finder close up to the left eye and look through the slit into the mirrors. Point the instrument in such a direction that the image of the distant object, as seen in the upper mirror, lies exactly above and directly in line with the thin edge of the wedge. At the same instant, glance past the wedge-edge and note some feature in the landscape which is in line with this edge, a tree, D, for instance. Now with the eye at the slit walk directly toward this object, D, counting the number of paces taken, still keeping the wedge-edge in line with the tree. Meanwhile the image of C in the upper mirror moves on out to the right and at the same time its image as seen in the lower mirror moves up from the left until it in its turn comes into line with the wedge-edge. At the instant this happens note how many paces, F, have been taken from the first observing station. Multiply this number by 10 and you have the number of paces, F, from the first point of observa- tion out to C. If you have learned to make a stride of 36 in., then the distances are known at once in yards, otherwise you must know the length of the natural stride before you can obtain distances in yards. Of course the paced distance can be measured with a tape-line. If the paced distance is 88 yards then C is 880 yards or half a mile away. It is evident that to measure with this instrument the distance to an object 5 miles away one must pace off half a mile. This Popular Science Monthly is sometimes inconvenient. It is therefo : desirable, for objects at this distance, or farther away, to use a range-finder whose wedge is of only half the angle described above; the 2-in. paper square must then be held at a 4o-in. distance in adjusting the - mirror strips. The paced distance is then to be multiplied by 20. This type of range-finder yields astonish- ingly accurate results if it is equipped with good mirrors. It is a scientific instrument based upon the laws of reflection of light — and surveyors’ triangulation methods and is worthy of any boy’s serious consideration. © A Convenient Pivoted Card File 4 for the Desk ' ILING systems are necessary in all lines of business, and for convenience of small accounts or for data a single tray is often applicable. The desk tray illus-— trated is especially designed and it fits into a slide eraies for it, so that it is never A Fame oe file tray pulls out the same as a drawer and turns on a pivot when drawn -in the way. Another feature of the tray is that it turns on a pivot and the cards face the person sitting at the desk. | Flanged bottoms hold the guide cards in place. There is a follower-block, simple — in construction and operation, that holds the tabs in a readable position. Side tabs, © as shown at A, permit more distinctive subdivisions. With each closing of the drawer an automatic angle-block tilts the cards back parallel with the follower-block. To further facilitate reference the index drawer is pivoted to its carrier-shelf. The frame of the drawer is made up of two thick ends to which thin bottom and ~ side pieces are nailed, the exact dimensions of which depend upon the size of the cards as well as upon the materials at hand. To the front end block, planed to serve as the angle-block B, the drawer face and handle are fastened. A pivot wheel C is nailed to the center of the drawer bottom. _ This wheel fits into a slot in the carrier- shelf D. The follower-block E, made of a wood base to which a spring and wire _ brace are fastened, slips under the side ~ pi of the drawer. Pushing it against ie the material filed causes it to grip fast. It is released by a slight vertical pressure. _ The most important part of this file is the angle-block. Usually the first tabs of an index are not visible, being wholly or Popular Science Monthly 625 If, instead of cards, manuscripts, themes or large size envelopes are to be filed, the drawer shown in J will prove a better arrangement. Cardboard shelves are slipped into the kerf grooves and form pockets for filing.—Epwarp R. SMITH. Three Methods for Finding a Chosen Card OR this trick the chosen card must be worked to the top of the pack. If it is there already, well and good; but if not, it eee ee arent see ——,7 ——— SEE fal /) WMA TPT AT TOT —$— TS \\) ———_—_S—SS EES manner of a drawer, the front and follower partly concealed by the face of the drawer. The automatically operated block B of this file is cut to a bevel, the lower surface of which is parallel with the follower-block F. _ Suppose that the cards are arranged as shown in illustration G. With the pushing of the drawer into its casing, as in H, the momentum of the cards tilts them back. When the drawer is pulled out the bevel prevents the cards from being thrown forward. In steel filing equipment this space between cards and drawer-head is _ an added protection in case of fire. Letails of the file parts which are made up to slide in an opening in a desk after the block holding the cards in a tilted position must be brought there by some means or other. This is generally an easy matter, even without sleight of hand, and can usually be effected under the pretense of looking through the pack. When the card is once at the top a false shuffle may be given, to throw the onlookers off the track. Then push the top card out sideways beyond the rest of the cards. Let the pack fall on the table. The resistance of the air will cause the top card to turn over and appear face upwards, all the other cards remaining face downwards. 626 Another method is as follows: Get the chosen card to the top of the pack. Slightly moisten the first and second fingers of the right hand, and take hold of the pack with the fingers above, thumb below. Jerk the hand containing the pack smartly down- wards, at the same time relaxing the fingers, and it will be found that the entire pack falls to the floor, with the exception of the chosen card, which will stick to the moistened fingers. This will be the only card left and the card selected. The third method is very similar to the preceding. The chosen card is worked to the bottom of the pack. Moisten the fingers slightly and take hold of the pack with the fingers below, thumb above. With the disengaged hand strike the pack smartly and at the same moment slightly relax your hold on the pack. It will be found that the entire pack will fall to the floor with the exception of the bottom card which adheres to the fingers. Piping Automobile Engine Exhaust Gas from Garage SPHYXIA caused many deaths in garages before it became generally known that a garage must be well ventilated and the doors left open if the automobile Wf 7Hole cut in doo ARain water pipe An old drain pipe on a garage floor to remove poisonous gases from the automobile engine One owner of a private garage avoided the necessity of keeping the doors open by piping the exhaust outside, as shown in the illustration. An old drain pipe was used for the purpose. It was connected in such a way that when the automobile was backed into the garage the end of the exhaust pipe entered the end of the drain pipe. This led down to the floor, where a long piece ran through the wall to the out- side and carried all unpleasant or dangerous fumes to the outside, leaving the interior free from the poisonous carbon monoxide gas.—P. P. AVERY. Se oe a Popular Science Monthly Edging Flower Beds with Old Bottles ARIOUS methods are used to con- struct edging for flower beds that will produce an effect in keeping with surround- ings. One simple way is to use a number of The edging around a flower bed made up of bottles buried part way in the ground . bottles, all the same size, set with their necks in the ground, outlining the shape of the bed. Bottles of different colors may be used, or alternate ones let into the ground deeper, making two levels for the bottoms, which have become the tops, similar to a paling fence. Flat bottles, shaped on the order of a flask, can be set in zigzag fashion, or like shingles on the siding of a house, to present a very pleasing appearance as a border for a small bed.—Louis M. WAHRER. Repairing a Broken Test Tube or Beaker HEN you have broken the top of a test-tube or beaker, do not throw it away, for there is a simple way to cut it off smoothly and make a new lip on it. Take a three-cornered file and heat the small end that goes into the handle. Now place the red-hot file on a spot below the break, which has been dipped in water, and hold it there until a slight snap is heard. Now lift the file off. You will see a tiny crack 14 in. long. Reheat the file and repeat the operation, following the crack around in a circle. The broken part can be lifted off and a clean-cut rim is the result. To make a flare, rotate the test-tube or beaker over a Bunsen flame until the glass commences to soften, then with a charcoal block, still rotating the tube, press the edges out. In a similar way a lip can be made by pressing down with one edge of the char- coal block. The hardest part of the work is to get the crack started. Sometimes filing starts it—MAaALcoLtm MAcurRDA. Making and Using a Casting Rod II.—The manner of making the cast and controlling the line | By Stillman Taylor AIT casting with the modern short casting rod is altogether unlike the : old method handling the nine foot bait rod. In the new style the casting is done from the reel, and after a little ‘Fig. 7. Thecontrol of the line is entirely reg- ulated by pressure of the thumb on the spool practice, it is easy to project the minnow or other weight a distance of 75 or 100 ft. Casting is good sport in itself apart from fishing, and by attaching a 4-0z. weight to the line, practice and contests may be indulged in upon any open lot, or in the public park. A good smoothly running reel is an important part of the casting outfit, and while the expert tournament casters often pay $25 or more for their jeweled reels, a very fine reel may be had for about $5, and serviceable ones as low as $1.50. The kind of reel to buy is of the long barreled type, having a capacity of about 80 to -——_— -——'e- ae _ Fig. 8. The underhand cast is started from this position, the tip being about breast high 1oo yards of line. A satisfactory reel is shown in Fig. 7, with which no trouble is likely to be encountered in making fairly accurate casts up to 150 feet. This reel costs about $1.75. A good silk line is likewise needed, and while the softer braided silk casting lines are somewhat easier to thumb and less likely to tangle up when you happen to get a backlash, the harder braids soak up less water and will prove most durable. For tournament use, soft braided lines are sig for fishing, pick out the hard braided ind. As the control of the line is entirely regu- lated by pressure of the thumb on the across the body in the direction of the cast spool, this “‘thumbing”’’ the line is easiest done when the spool is well filled with line. It is not often necessary to purchase a longer line than 50 yards, and if this amount does not entirely fill the spool of the reel, simply wind on a length of common string to form a core, and wind on the line over it to fill up the spool. Many of the expensive casting reels are fitted with cork or wooden cores or arbors, but the string core will answer all purposes. Two styles of casting are much used, the underhand and the overhead cast. As the whole secret of casting lies in thumbing the line, the novice should grasp the rod in the correct manner, as shown in Fig. 7. The underhand cast is the easiest, and 627 628 is made by reeling in the minnow or plug until it is about 6-in. from the tip. Release the click or drag, press the ball of the thumb firmly on the line on the spool, and swing the rod across the body until it is in the position shown in Fig. 8—the tip being about breast high. . Now bring the rod quickly forward across the body Fig. 10. The overhead cast is generally used by fishermen and tournament casters in the direction you want to cast, and relax the thumb sufficiently to let the line run out freely, but still keep enough tension on the spool to prevent it from over-running and causing a back lash. The correct underhand cast is completed as shown in Fig. 9. tus Fig.11. The bait is projected in the direction the caster is facing and the finish is as shown The overhead cast is more largely used by both fishermen and tournament casters; for a greater distance is covered, and after - Popular Science Monthly a little practice a greater degree of ac- curacy is possible. It is made similar to the underhand cast, but the rod is carried back over the shoulder until it is almost horizontal, as shown in Fig. 10. The arm is now snapped quickly forward and suddenly checked when the rod has reached an angle of about 45 deg., the thumb is partly relaxed, and the bait is projected in the direction the caster is facing. The finish of the overhead cast is shown in Fig. 11. When reeling in the line for another cast, and when playing a fish, the skillful caster prefers to spool the line evenly on the reel by guiding it between the thumb and finger, as shown in Fig. 12. When casting for bass, pickerel and other fresh water game fishes, the cast is finished by merely checking the revolving spool as the bait hits the water. The splash of the minnow or other artificial bait, rather attracts than frightens the fish, hence the angler may use any form of bait desired. The artificial baits now used are of three prominent types; those used on the surface, the diving or underwater baits, and the top-water or weedless lures. The minnow Fig. 12. by guiding it between the thumb and finger The line is evenly spooled on the reel form, which floats when at rest, but dives when reeled in, is the best for all-around use, equally attractive for pickerel and black bass. However, there are many different forms of varying sizes and colors to choose from, some for general and others for special purposes. To become a successful angler the caster should know something about the habits of the pickerel or bass in his neighboring waters. In the early days of Spring, when the water is cool, bass are likely to be found in the shallower parts of the stream or lake during the day, and casting should be done around rocks, sand-bars, old stumps, or submerged branches. Pickerel will also be found in the warmer shoal water during this season, and as both species are feeding on minnows and hel- gramites, the best baits are the common _ baits may be wooden minnow and the under-water types. For colors, most casters agree that on bright, clear days, and in clear waters, the red and white, red and gray and similar colors, are best. For cloudy days and for casting in muddy waters, the red and green, and yellow colors are good. For sun-down casting, the white or luminous minnows are very attractive. For summer casting, when the water is warm and Popular Science Monthly 629 Making a Cabin Tent out of Ordinary Sheeting PORTABLE tent, easily carried, quickly erected, adapted for any cli- matic conditions, and capable of housing four or five persons with comfort may be constructed of a few yards of common sheeting, a small reel of wire, two dozen nails, and a package of safety pins. The entire outfit weeds and lily pads appear, the bass work out into deeper and cooler water, and the pickerel will be found near the lily pads. The regulation minnowandall ‘the under- water baits are very success- ful. lf the weeds are especially thick, one of the weedless used, ora weedless or “buck tail” hook substitu- ted for the usual _ treble afternoon cast- Nail in pole end ing—and the K Detail of side qe and end spanners will fold up in a rolb.2 46 long, and less than 6 in. in diameter, and weigh less than 7 |b. Of course regular tent cloth may be used, but in case that should not be available, or- dinary sheet- ing, 90 in. wide, will prove satisfac- tory. At one end of the sheeting make a wide seam. That is the only sewing re- quired to make it ready for use. The strip should not be less than 7 yd. as this is de- Sheeting ~ A early morning and late after- noon hours are the best ones for summer fishing—work around the mouth of any brooks or streams that empty into the lake or pond, and use a diving or under-water bait. Keep the bait always in motion.. Do not allow it to remain floating after a cast, but commence to reel in as soon as it strikes the water. As a general thing, beginners reel in too fast, and keep the bait surging along at motor-boat speed. This is a mistake, for no fish can strike at this high speed. If you are out after big fish, reel in slowly, and keep in mind thata well placed cast of 75 ft. is more likely to prove successful than a 100-ft. cast with a backlash at the end of it. A tent that will house four or five persons is constructed of a few yards of common sheeting and materials from the woods signed to form the main cov- ering for the tent. The poles selected may vary in length, and thus vary the amount of sheeting required. In addition to this main sheet two tri- angularly-shaped sections of the same - goods are provided, the edges of which should be hemmed. To the long side of each triangular piece, tack a strip of netting 4 ft. wide and at least 8 ft. long. The tri- angular sections and netting form the ends of the tent. The frame which holds the tent fabric is made of four poles, each 8 ft. long. These should be driven into the ground 6 in. or more, 8 ft. apart, to form the four corners. 630 In order to make the gables of the cabin the ends of horizontal cross-pieces, or poles, are secured to each pair of uprights, 31% ft. from the ground. ‘The tops of the saplings are then brought together so as to form two arches, one for each end of the cabin. The horizontal spanners are 7 ft. long. A ridge pole is then laid on the forks pro- vided by the two arches, and side spanner poles are secured to the arched poles. The intersecting parts of the various saplings are fixed in place by means of suitable wire or twine. Soft wire is preferable, as it can be quickly applied, twisted and secured by means of pliers. Soft annealed piano wire is the most serviceable. A tinned wire, about 18 gage, is also good for this purpose. We now have the frame ready for the parts necessary to carry the tent cloth; for it is not desirable to stretch the sheet over the wooden frame. We may take a lesson from the umbrella frame which has light ribs to support its covering. Wires are used to support the sheet of the tent. A few suggestions as to the correct way of attaching these wires may be of great service to the novice. The poles should have their ends cut off square witha small saw. A hatchet might split the wood. Several sets of wires should be prepared beforehand. The end of each wire should have a twisted loop to attach to one end of a pole. Wire nails, 214 in. long, are best adapted for holding the wires. These should be driven into the ends of the cross and longitudinal poles, or spanners, the loops affixed and the loose ends of the wires attached to the other ends of the respective poles. The main sheeting is then unrolled and strung over the five taut wires, one end of the sheet being secured to the lower wire, which is threaded through the seam. The other end of the sheet passes behind the other base wire. After stretching the sheet tight the surplus end is secured to the taut portion. The triangular end sections are then attached with safety pins, or buttons or snap-fasteners may be provided for the purpose. It will thus be seen that the entire fabric forming the tent is suspended on wires and does not come into contact with any portion of the wooden frame. It is not necessary in a cabin tent of this construction that the poles should be driven into the ground. Instead, a wire may be stretched across to connect the lower ends of the front and rear arches. Popular Science Monthly Holding Papers on a Movable Sloping Desk-Top T is difficult to hold letters or other pieces of paper on the surface of an ordinary sloping top desk, even though paper weights are used for the purpose, as the desk-top must be raised at times i Vy Yr i la) ( OY Brass wire clip to hold sheets of paper on a sloping desk top that is raised occasionally to gain access to the contents within. The illustration shows how a permanent clip or holder can be made of a piece of light brass wire and spring and placed on the desk-top. A small hole sufficient to take the wire size is drilled down through the desk-top. It in no way interferes with — the opening and closing of the desk- top.—F. W. BENTLEY. Keeping Oil from the V-Belt of a Motorcycle IL leaking through the shaft bearing and running on the pulley face and entering the groove caused con- siderable trouble on a V-belt rn _ or drive of my motorcycle. This difficulty I easily over- came by attaching a steel flange to the inner surface of the pulley, which had a diameter considerably larger than that of the pulley flange. This prevented the oil from getting into the pulley groove by caus- ing it to drip from the flange edge. The flange was out of the way. through =: . Crank base Cottier mtr it , Distance trom edge of pulley one inch A wide steel flange keeps oil from belt _ Cutting Brass Tubing Rapidly on a Buzz Saw RASS tubing can be cut off to the required lengths very much faster on a : ares saw than by any other method. A _ square cut is obtained in this way and by cutting with a set stop, lengths are made -exact within a few thousandths of an inch. As compared with cutting off in a lathe or _ milling machine or by hand the buzz saw Popular Science Monthly ~ 631 A Labor Saving Wood Lift Built In Like a Dumb-Waiter PROPERLY built wood lift is a labor- saving device and may be made in- conspicuous by concealing it by means of a paneled door in the wall, as in the illus- tration. An open-faced box or cage is built and placed in two main braces, to which the pulleys are fastened, serving as guides. It runs between two heavy up- IL BACK OF LIFT - FIXED ROPE i LIFT PULLEY SYSTEM Parts, guide rails, location of ropes and counterweight for the construction of a wood lift to be built in a house for the saving of labor. will show a multiplied production. Sheet brass can be cut in the same way in thick- nesses.up to 14 in. The metal heats in the thicker pieces, and gloves must be worn. A circular saw—not an ordinary wood- cutting saw—is used for cutting metal. These saws have a different temper from wood saws, have finer and different shaped teeth and have very little set. The tubes are held and the work is done just as if they were wood pieces. It is concealed by a panel in the wall rights equipped with guide-rails. A third upright makes a ‘‘well’’ for ropes and a counterweight. Two lengths of 3/16-in. rope, 4 and B, with ends fixed in an over- head pulley- block, run to cage pulleys and back to sheaves fixed in the overhead block, and thence to the winch, as shown. A third length C connects the car with the counter- weight. A lift built to an upper floor, with doors in the first and second floor walls, is almost 632 useless unless two cars are placed in the shaft. A two-car system is ideal where the lift is carried to an upper floor with openings on both floors. The upper box has guides of a special design, as shown, iicamc AAAAAAAUAANRARRMRRNN yANAARARRERARRREREREES UPPER CAR WITH EXTENSION GUIDES to allow the lower cage ropes to pass. The winches are set at right angles to permit each lift to be worked inde- pendently. Ifthe upper lift alone is to be used the lower cage may be kept down. The upper winch should be high enough to permit its use when the lower cage is down, as the accompanying drawing shows. Frequently, because of small capacity, difficulty of operation and inaccessibility, it is as easy to carry firewood upstairs in the old-fashioned way. But this lift has a large capacity and its open side not only offers its contents readily, but provides a means of cleaning. While it is often possi- ble to build a lift beneath a stairway, con- ‘venience should not be sacrificed to save a few feet of floor or bookcase space. There should be some way of reaching the pulley- block at the top of the shaft to oil the pulleys—EpDwarp R. SMITH. PULLEYS WINCHES AT RIGHT ANGLES An extra car for the dumb waiter shaft Improving Your Piano by Moistening the Air in the Room RELIABLE piano tuner says that pianos are often injured because they become too dry. Keep a growing plant in the room with the piano and see how much more water it will require than the plants in any other room. A large vase with a wet sponge kept near the piano will supply moisture.—C. A. WOLFE. Popular Science Monthly A Simple Camera Attachment for Photographic Enlarging Aes owning an ordinary folding ‘pocket camera with adjustable focus can easily make and use this enlarging out- fit. The sketch shows a longitudinal sec- tion and gives an idea of the general arrangement. The box is fitted up with an electric lamp, socket and reflector. The other end has a square hole the size of the opening in the rear of the camera cut into it. Two clamp pieces are cut out and fastened to the box as shown, so that the camera is held firmly to the opening in the front of the box. A slot is recessed over the hole so that a sheet of orange-colored glass will slide in it and cover the square hole. The base-piece is extended several feet beyond the camera and is slotted its entire length. A sliding screen of some light- weight material is made and fastened in the slot in the base with a thumb-screw, as shown. A sheet of fine white tracing paper should be fastened over the inside of the hole in the box so as to diffuse the light from the reflector and prevent unevenness of light distribution. Place the film or plate in the opening in the back of the camera and turn on the light. Have the sheet of orange glass in the groove provided for it back of the camera. Darken the room and pin a sheet of bromide or other enlarging paper on the sliding screen with thumbtacks. The orange light coming through the lens will furnish sufficient illumination for this. Now focus the image on the paper by moving the camera bellows in or out and by moving the screen to and from the Switch Clamp a Screen Reflector Comers a, amp i wt Slot For - Glass lamp —S Pe Sa, ao Enlarging pictures with an ordinary camera placed on a box inclosing an electric light camera until the correct focus is obtained. Now slide out the orange glass and expose the paper for the required time, after which replace the glass to stop exposure. Develop the paper in a red or orange light only. A sixteen candlepower mazda light will oper- ate the apparatus.—B. FRANcIS DASHIELL. Popular Science Monthly A Teeter Swing for Public or Private Playground THE illustration shows a way to make a permanent amusement device for chil- dren’s playgrounds. It is inexpensive to build and if erected will prove as attractive to children as many other more elaborate de- vices. Two planks A 16 ft. long, 10 in. wide and 2 in. thick form the sup- port for the teeter B, which is made of two pipes, each 114 | in. in diameter and 9g ft. long. The seats C consist of a board strapped on the pipe ar- rangement D which provides an opening for the legs, mak- ing it almost impossible for a child to fall out of the seat. The support for the main pipes is shown at E, each end of which passes through the planks with a coupling on the ends to prevent the piece dropping out of the holes bored in the planks. The plank ends are sunk into the ground at one end and fastened together with a bolt F. The piece G is made from 144-in. pipe - strapped to the planks at H. Window cord is at- tached at the ends J. Two children, even of very un- equal weight, can have an enjoyable time on this os, Details of the parts for making a teeter swing swing, as the teeter is worked by pulling on ° the cords rather than by balancing weight. The riders can use their feet to help the movement. If required, a brake can be easily added to prevent the seats striking the ground.—James E. NoBLe. A playground teeter made of pipe and fittings for the swinging part and planks set in the ground for the supports 633. An Interesting Experiment with Sulphate of Soda N experiment of an unusual character may be made with a_ thoroughly sterilized glass rod and a supersaturated solution of sulphate of soda. The phenom- enon is so extraordinary that any one who may make the trial will find it difficult to clearly explain the result. To make it more interesting four glass tumblers should be used. . Place them in a saucepan of cold water with their bottoms resting on cardboard, then bring the water to a boil. Meantime dissolve some ‘ sulphate of soda in an- other vessel, by pouring the soda sul- phate into boiling water until the water will take onno more. Now remove the tumblers and place them upon a board. Fill them with the saturated solution and stand them aside to cool in a place free from vibration. If this part of the work is done at night the solution will be quite cold in the morning and ready for the test. Do not disturb the contents of the tumblers, or crystallization will set in at once and spoil the experiment. Take an ordinary round glass stirring- rod that is about 1 ft. long and 5/16 in. in diameter and clean it well; then in the flame of an alcohol or other burner heat about 3 in. on one end of the rod almost red hot and place it to cool in such a position that the heated end will not touch anything. As soon:as cold, take the rod and dip the end that was heated into one of the tum- blers containing the solution. No action whatever will take place; but as soon as the other end is inserted, the salt will im- mediately start to crystallize and will rapidly continue to do so until the solution becomes a solid mass. If each tumbler is stirred at the start with the sterilized end of the rod, the same. performance will take place. Drying Fruits and Vegetables A simple method of drying your surplus sup ply of fruits and vegetables for future use HE advantages of drying vegetables are not so apparent for the farm home as they are for the town and city household, which has no root cellar or other place in which to store fresh vegeta- bles. For the farmer’s wife the new meth- ods of canning probably will be better than sun drying, which requires a somewhat longer time. But quicker methods of dry- . ing are now in use, and the dried product holds an advantage in that it usually requires fewer jars, cans or other containers than do canned fruits or vege- ‘tables; also dried ma- terial can be stored in receptacles which can- not be used for canning. Then, too, canned fruit and vegetables freeze and cannot be shipped in absolute safety con- veniently in winter. With a simple and in- expensive equipment all housewives can save quantities of food which are too small con- veniently tocan. A few sweet potatoes or apples or peas or even a single turnip can be dried and saved. Even when very small quanti- : . ties are dried at a Se time, a quantity suf- ficient for a meal will soon be secured. Small mixed lots of dried vegetables, such as cabbage, carrots, turnips, potatoes, and onions, can be packed together and used for soups and stews. Three principal ways are applicable for the home preparation of dried fruits and vegetables; namely, sun drying, drying by artificial heat, and drying by air blast. These, of course, may be combined. In general, most fruits or vegetables, to be dried quickly, must be shredded or cut into slices, because many are too large to dry quickly or are covered with a skin, the pur- a - A We ws, mt ‘(UT Rg f 2 E a oi = - pose of which is to prevent drying out. When freshly cut fruits or vegetables are to be dried by means of artificial heat, they should be exposed first to gentle heat and later to the higher temperatures. If the air applied at the outset is of too high a tem- perature, the cut surfaces of the sliced fruits or vegetables become hard, or scorched, covering the juicy interior so that it will not dry out. Generally it is not ‘desirable that the air temperature in drying should go above 140 deg. or 150 deg. F., and it is better to keep it well below this point. Insects and insect eggs are killed us by exposure to heat am ||K ow: of this temperature. 1 | It is important to know the degree of heat in the dryer, and this cannot be determined very ac- curately except by using a thermome- ter. Inexpensive oven thermometers can be found on the market, or an ordi- nary chemical ther- mometer can be sus- pended in the dryer. If a thermometer is not used, the great- est care should be given to the regula- tion of heat. The temperature in the dryer rises rather quickly and the product may scorch unless close attention is given. ryrte]| ayn Ty \ MMC A Feshit made of laths or strips of wood to hold trays of galvanized wire mesh and swung over the range with a crane _ The reason sun drying is popularly believed to give fruits and vegetables a sweeter flavor is probably because in the sun they are never scorched, whereas in the oven or over a stove, scorching is a common * occurrence. A cheap and very satisfactory dryer for use over the kitchen stove is one that was worked out by the Department of Agri- culture at Washington. Any handy boy or 634 over the oil or gas) [fh stove, and it will fos utilize the hot air [in which rises during | See the cooking hour. i ieee It can be raised out =| Lest of the way or swung = [i R253 to one side by a jihsst~ss crane made of lath = [i SSs3s<3 when the stove is re- Se quired for cooking f[', JERAtS purposes, and low- kW<7 Sh ered or swung back Popular Science Monthly carpenter can make one from a small quantity of fine mesh galvanized wire netting and a number of laths and strips of wood about 1% in. thick and 2 in. wide. ' The screen may be tacked directly on the framework to make the drying shelves, or the framework can be made to support separate trays. By using two laths nailed together the framework can be stiffened and larger trays made if desirable. This form or any of the lighter makes of dryers can be suspended from the ceiling over the kitchen range or to utilize the heat which otherwise would be wasted when the top of the stove is not in use. Another home- made cookstove dryer that can be used on a wood or coal range or a kero- sene stove can be made easily and cheaply as shown in the second illustration. The dimensions of the base are 24 by 16 in., the height being 36 in. A base 6 in. high is made of galvanized sheet iron. The base slightly flares toward the bottom and has two small openings for ventilation in each of the four sides. On the base rests a box-like frame made of 1 or 1-in. strips of wood. The two sides are braced with 114 in. strips which serve as cleats on which the trays in the dryer rest. These are placed at intervals of 3 in. The frame is covered with tin or galvanized iron which is tacked to the wood strips of the frame. Thin strips of wood may be used instead of tin or sheet iron. The door is fitted on small hinges and fastened with a thumb latch. It opens wide so that the trays can be re- moved easily. The bottom of the dryer is made of a piece of perforated galvanized A cookstove dryer that has a metal base for setting on top of a wood or coal range 635 sheet iron. About 2 in. above the bottom is placed a solid sheet of galvanized iron which is 3 in. less in length and width than the bottom. This sheet rests on two wires fastened to the sides of the dryer. This prevents the direct heat from coming in contact with the product and serves as a radiator to spread the heat more evenly. The first tray is placed. 3 in. above the radiator. The trays rest on the cleats 3 in. apart. A dryer of the given dimensions will hold 8 trays. The frame of the tray is made of I-in. strips on which is tacked. galvanized screen wire, which_ forms the bottom of the tray. The tray is 21 by 15 in., making it 3 in. less in depth than the dryer. The lowest tray when of placed in the dryer is pushed back, leav- (| ing the 3-in. space in front. The next tray is placed even with the front, leav- ing a 3-in. space in the back. The other trays alternate in the same way. This permits the current of heated air to pass around and over the trays. A ventilator opening, about 2 in. wide and 6 in. long, is left in the top of the dryer, through which the moist air may pass away. This principle of construction is followed so that currents of heated air will pass over the product as well as up through it, gathering the moisture and passing away. The movement of the current of air in- duces a more rapid and uniform drying. The upper trays can be shifted to the lower part of the dryer, and the lower trays to the upper part as drying proceeds. If fruits or vegetables are packed in tight containers immediately upon being dried thoroughly, they will remain just as brittle as they were when taken from the dryer. If, however, they are not dried thoroughly, they will ‘‘sweat’’ and soon mold. To prevent this the material should be examined within 24 hours after packing, and if it appears moist, dried further. 636 A Bracing for an Iron Pipe Fence Post HE illustration shows how a fence, the posts of which were ordinary iron pipe, was braced with a bent piece of the same sized pipe so as to stand a severe A cufved post brace set in concrete to make a solid support for stretching wire tightly pull when the wire fencing was stretched -onit. The brace and the posts were filled with cement, and the ring was inserted in it. The ring was shaped from a piece of heavy, flat wrought iron, which had enough shank to fit solidly into the pipe. The bases for the posts were built first and the remainder of the concrete work was left until later on, so that should any cracks develop along the edge of the post base they could be easily located and remedied.—JAMES M. KANE. Attaching Linoleum to a Cement Floor GOOD cement for attaching linoleum to a cement floor may be made as follows: Manila gum 15 parts, brown rosin 20 parts and thick turpentine 45 parts, all by weight. -Pulverize the rosin and gum and heat until melted; then thin out with denatured alcohol, using 20 parts. Casing for Carrying Tube Cements Without Damage AVING trouble keeping the rubber cement tubes in the tool bag of my bicycle clean, I devised the tube-carrying case shown in the illustration. It consists of a brass tube about I in. longer than the cement tube and a little larger in diameter, with one end plugged and the other corked.—AxEL H. JOHNSON. Sen i a =7 Ce ————— i y) y) Y; Small brass case in- closing tube cement Popular Science Monthly A Silver-Plating Bath and How to Use It HE most important attribute for the amateur plater to cultivate is caution. © He is working with some of the most deadly poisons known to chemistry. He should not inhale the fumes given off in mixing solutions and should not get. these solutions on his hands or clothing. No vessel employed in plating should be used for any other purpose. The electric current for plating should be supplied by some form of steady current battery, giving low voltage and high amperage, such as the Edison primary, Bunsen, or Fuller cells. The cells of the battery should be connected in parallel. The current must not be above two volts. For the anode, purchase a sheet of pure silver from a jewelry supply house. The. sheet surface should contain from 1 to 4 sq. in. Such a plate 1/32 in. thick will cost from 75 to 90 cents. The position of the anode should be adjustable; so that more or less of its surface can be immersed, and so that it may be moved toward or away from the article being plated. A pair of heavy wires should be provided, long enough to reach across the top of the plating tank. When placed in position the wire carrying the anode is connected with the carbon of the battery, and the one carrying the article to be plated is connected with the zinc. Cut several lengths of No. 14 or No. 16 copper wire; bend into a hook at the top, to hang on the rod connected with the zinc, and long enough to reach to the bottom of the tank. These are called ‘slinging wires,’’ being twisted around the work suspended in the solution. The next operation is to mix the solutions. Only pure chemicals should be used. Grad- uates, mixing vessels, evaporating dishes, mixing rods, etc., must be chemically clean. Use glass rods or tubing for stirring rods. The nitrate of silver bath is made by dissolving pure scrap silver in a 25 per cent nitric acid solution. After the solution has been evaporated, the resultant crystals are dissolved in two quarts of distilled water. In another vessel, mix I oz. of potassium cyanide crystals in water, and add this slowly to the silver nitrate solution. Enough of the two solutions have been mixed when a precipitate forms. The liquid should be poured carefully from the material in the bottom, which is silver | cyanide. This precipitate should be thor- oughly washed in pure cold water, Popular Science Monthly Make up another solution- of 1 oz. of the cyanide salts in a quart of pure water and pour enough of this over the washed precipitate to dissolve it, stirring _well. When a clear, colorless liquid results, add more of the cyanide solution as there must be a slight excess of cyanide in the plating bath. Add enough water to give the desired quantity or strength. If pure silver nitrate can be obtained, it may be used instead of the metal solution. Pure nitrate will contain approximately 635 grains of the metal in each 1000 grains of the salt. A very good solution for ordinary work can be made by dissolving 1 oz. of pure silver nitrate in 40 oz. of water and pro- ceeding as above to throw down and wash the precipitate and redissolve it in the cyanides. By adding two quarts of water, it is ready for use. Preparing the Article to Be Plated Having prepared the apparatus and solutions, the preparation of the work to be plated is next in order. Plating will cover no defects, such as stains, scratches, etc., but is likely to make them more prominent. Every blemish should be re- moved with a file or emery paper and the surface polished. To remove corrosion from brass, copper, etc., soak the article in a solution made by adding—a little at a time with free stirring —3 oz. of sulphuric acid to 4 oz. of water, and when this has cooled, pour in 134 oz. of nitric acid. Be sure to add the sulphuric acid to the water a little at a time, allowing it to mix and cool before adding more, finally adding the nitric acid. Soak the work to be cleaned in this solution until all the corrosion is dissolved, or softened so that it may be removed with a stiff brush; then rinse thoroughly and polish. The time required to remove corrosion will vary from a few seconds to an hour or more. Those parts which are to have a polished appearance when finished must be well polished before they are plated. This may be done in any way convenient. To use a polishing lathe or stand is the best method. Cloth disks, from 3 in. to 6 in. in diameter and 14 in. to 1 in. thick may be made, some of canvas or other heavy, hard cloth, and others of flannel or muslin for the finishing touches. They should be used with powdered abrasives, using emery for the rougher operations and finishing with fine polishing powders and soft disks. If a 637 lathe is not at hand, use brushes, and cloths. hen the work has been polished it should be washed thoroughly so that no traces of the polishing materials re- main. After polishing and washing, the articles should be attached to the slinging wires so that they need not be touched by the hands again. Soak the work a few moments in a hot solution made of a table- spoonful of potash in a pint of water. This is the potash “dip” and is to remove all traces of grease and dirt that may have been left. After being given the potash dip the work is laid on a board where a small stream of water may flow over it while it is brushed with a stiff bristle brush, kept wet and occasionally dipped into pow- | dered pumice stone. This will remove all the potash and grease and also give a slight grain to the surface of the plated - article. After scouring, rinse the work well in running water and soak for a few seconds in a solution made by dissolving an ounce of potassium cyanide in a pint of water and hang at once’in the plating bath. Have the anode in position and the battery connected before hanging the work; other- wise the cyanide in the bath will attack the metal and injure the bath. The article will become white in a moment and a plate of silver will be deposited in from ten to fifteen minutes. The Finishing Touches When plated heavily enough, the article should be taken from the bath, rinsed in boiling water and dropped into fine, warm sawdust to dry. Exposure of a freshly plated surface to the air and light while it is covered with a film of the plating solu- tion, will cause it to turn yellow. When dried in the sawdust, it should be brushed and will appear a frosty white. The first finishing is scratch brushing. A small brush wheel of fine brass wire is held in a lathe or polishing stand, and kept wet with stale beer or oatmeal water. The plated surface is held against it. Without a machine a bristle brush may be used, if stiff enough. When all the chalky whiteness has disappeared and the metal shows an even, dull color, give it another rinsing in plenty of water and dry. It is now ready for buffing and polishing with soft materials, light pressure and fine polishing powders. If an extra heavy and durable plate 638 is desired, it is best to proceed as follows: Apply a first plate and finish it. Then go over the operation again, dipping in the hot potash solution, rinsing, scouring, dipping again in the cyanide solution and replacing in the plating bath and then finishing and polishing a second time. This will give better results than if a very heavy plate were put on in one operation. Articles of different metals or alloy, will not plate at the same time. . This will be noticed if there is a soldered joint in the work. Such joints must receive treatment so the solder of the joint will take the plate as well as the rest of the surface. To plate on a soldered joint, make an ounce or two of saturated solution of sulphate of copper and distilled water. Add one-tenth of its volume of sulphuric acid. After the work has received the final scouring and rinsing, and before dipping in the cyanide bath, take a piece of small, clean, iron wire, or a small brush made of iron wire, and dip it in the sulphate solution and draw along the joint. A film of copper will cover the solder instan- taneously and to this the silver will readily adhere. If the current is too heavy, the silver film deposited will lie loosely, with a hard dark appearance, and such a plate will not polish. This condition may be remedied by moving the articles farther from the anode and by raising the anode so that less of its surface is in the bath. Too high voltage with too little amperage will also cause a deposit of this kind. Articles being plated should be kept in gentle motion or moved frequently, as the solution has a tendency to settle, re- sulting in uneven plating. Too much cyanide in the plating bath will cause the anode plate to assume a white frosted appearance with rough edges. A deposit from such a bath cannot be polished readily. -Too little cyanide will cause the anode plate to be covered with a dark deposit having a hard, close-grained appearance, and the plating will be dirty and uneven. When either condition ap- pears, it should be remedied by the addi- tion of a small amount of silver solution, or . of the cyanide solution, whichever is necessary. When a bath works properly and the anode remains clean and bright, the only material to be added is a little distilled water occasionally, to counteract evapora- tion. A plating bath will remain fresh for a long time if the evaporation is taken care of, Popular Science Monthly and the vessel protected from dust and strong light. All operations connected with the actual depositing of the plate and the first finishing should be conducted in dim light. A strong bright light will have a harmful effect on both the plating solution and the freshly deposited silver. A Simple Toy Motor Run with Dry Sand HE only materials needed in the con-— struction of this sand motor are 2 needles, 1 cork stopper, some cardboard and heavy paper, glue and a quantity of fine sand. The stopper should be a very large size. On both ends of the cork mark off with a pencil a 6-sided polygon. With a sharp knife cut the cork as shown in Fig. 1. Cut six pieces of cardboard for the blades of the sandwheel and glue them to the cork as shown in Fig. 2. Push a needle, eye first, into each end of the cork, as shown. The sand falling from the cone drops on the edge of the uppermost blade of the wheel The framework of the motor shown in Fig. 3 is made from three pieces of card- board glued together. The sand wheel is mounted at the bottom of the frame by pushing the needles through the cardboard. From the top of the frame a paper horn, filled with sand, is suspended by a short piece of thread. The sand sifts down over the blades of the wheel through a hole in the end of the horn. A small cardboard box should be placed under the wheel to catch the sand as it drops from the blades. A small grooved pulley wheel may be attached to one needle end and used with a thread for a belt to turn a light toy machine. The wheel can be fastened with a bit of wax. The sharp ends of the needles should be broken off.—E. P. THORNTON. Wigw By HJ. Blackwell See tire YS ——— OR the person always carrying a camera in the woods in search of _ pictures the wigwam illustrated will be of considerable interest, as the tripod of the camera equipment is used for the sup- port. The other necessary parts are four pieces of 2-in. material 34 in. thick, two 23 in. long and two 28 in. long, three small blocks, three hinges, two pieces of 14-in. rope, each 9 ft. long and 4 yards of cloth 34 in. wide. The four pieces are fastened together as shown at A, placing the hinges on the ends of the joining parts. One of the blocks is cut like a triangle and fastened at the back to one piece as shown. The other two blocks are cut rectangular and nailed to the inside surfaces on the ends of the pieces not joined with a hinge. Holes are bored in these blocks about 14 in. deep to admit the ends of the tripod legs. Holes 1 in. in diameter are bored through the pieces as at B, C, D and E. Center of top am Made of a Trip od ie ee A loop about 5 in. in diameter is made of a scrap of cord or rope and placed over the top of the tripod after the feet are set in the holes bored in the blocks. Tie a knot in one end of one rope and run the opposite end through the hole B, up over the loop, down and through the hole C; draw up snugly and tie the end. Run the other rope through the holes D, £ and the loop in the same manner, and tie knots in the ends. A stick with a notch in each end and about 16 in. long is placed in the tripod at F before the last rope is drawn in place. When this is complete the frame may be picked up and carried without fear of its falling apart. The cover may be of burlap, canvas, duck, denim or muslin. It is made of two pieces, each 2 yards long. Sew them together as shown in the illustration. The two pieces of cloth are sewed together in an L-shape, then wrapped around the tripod legs, and tied down to form the wigwam top, with a front opening at the point where there is no base 639 640 This is placed over the tripod top, locating place G on the screw-plate of the tripod. The corner of the cloth H is fastened at D; then the cover is carried around the frame, folding where necessary. It is then trim- med on the lines J, J and K. The trim- ming should. not be done until it is in position on the frame and pinned. After shaping it in this manner the pins will hold it so that the cover may be removed for sewing. When complete it can be dropped over the frame and fastened to the base pieces with thumb tacks. A Siphon Made Out of Gas Pipe and Fittings A SIPHON is very frequently needed for many purposes about a manu- facturing plant. The illustration shows how a very practical siphon can be con- structed from pipe fittings, and which will work very satisfactorily under almost any circumstances. A I-in. tee is used for the body, .. the vertical openings being yal respectively in- * V4to 38 reducing take and de- bushing. livery. In the ——— horizontal open- ing is placed a Yy to I-in. re- ducing bushing. A \% by 4-in. nipple is threaded for A siphon made of pipe and fittings length and started into the bushing. . When a few threads have passed the inner side of the reducing bushing, a 4 in. street el is caught on the end of the nipple and is of course turned on as the nipple enters the bush. As a result the nipple will be tight in the street el when the lower or nozzle end of it is at about the center of the tee. The hexagonal upper portion is cut from a 14 to 3%-in. reducing bushing, leaving a nut, which is run up on the 4-in. nipple before entering it; but it is after- wards tightened against the 4 to 1-in. reducing bush, affording a very practical lock for the nozzle. When the steam is turned into the 4%4-in. connection, the de- vice will afford a very practical and satis- factory siphon for all common lifting purposes generally arising around the shop or plant. Even if the required fittings had to be purchased they would cost very . little.—F. W. BENTLEY. about 3 in. of its Popular Science Monthly Making a Miter Box for Cutting Trestle Legs ib doing some odd jobs one day I found that it was necessary to have a trestle, and as there was none at hand I collected A piece of wood with gage sticks set in a vise to cut the miter on trestle legs the material for making one. Then to cut the miters for the legs became a problem. I did not care to lay out each leg separately to cut the right miter. After making some calculations an emergency miter box was made as illustrated. It consisted of a piece A, of the same stock used for the legs, and three pieces B, C and D, nailed to the sides in such positions as to make the proper angle for the miter. A nail placed in the piece D, as shown, served as a stop.—JAMEs M. KANE. Replacing Tongue in a Fancy Brass Hook oie A SET of four fancy brass snap hooks was given to me for repairs and on account of being unable to find a duplicate I replaced the Clock spring broken hinged Se rere member with a SON _ piece of flat POS clock-spring as =a Ind, shown. It was é’ SLA soldered in place instead of being riv- eted. The original tight- ening spring was left in place to straighten the clock-spring. A portion of the flat spring was cut off to allow more freedom in opening.—JAMES M. KANE. A flat clock spring re- placing a snap tongue pee ies: 4 ag aT, iW. Kerley, Teacher of Manual The Popular Science Monthly in the Schools The modern teacher vitalizes his subject. He tries to show the applications of a scientific principle to daily life. The new machines and the new wonders of science are based on the fundamental principles ex- plained to pupils. The PopuLtar Science Monruty has aided teachers of Science and Manual Training in showing how the fundamental principles are applied in new discoveries ani inventions. ~ Over 1,500 schools are now using the PoPuLar ScrENCE Monruczy for classroom instruction. Here are extracts from letters chosen from hundreds sent in by teachers. They are only a few of the many ex- "pressions of appreciation received: oe felieve every teacher oe mechanical science or manual training should use the PopuLar SciENcE MONTHLY as a _ Service. book... My students take a eat interest | in. the lectures taken om ‘it. Training, Estherville spt School, in Estherville, Ia. es ‘table. The magazine was read more by the _ boys than any other on our reading Ralph E. Roverof, Detroit, Mich. For use in supplementing a_ high school physics or chemistry course I think PoPpuULAR SCIENCE MONTHLY _ has no superior in the line of current literature. George E. Davis, Teacher of Physics and Chemistry, High School Institute, Mishawaka, Ind. POPULAR SCIENCE MoNrTHLY is very popular with our boys, in fact so much so we find they prefer reading the magazine to studying their regular school work. Personally I find the magazine helpful and_ interesting. New ideas are continually coming up within its covers, and suggestions for rearrangement of work. L. D. Whiting, Supervisor, Manual and Physical Military Training, Fal- mouth, Mass. We use the PopPuLAR SCIENCE MONTHLY regularly in our depart- ment of the school, and many of the boys I notice bring in copies of it almost every month, and figure and work on some of the projects. C. R. Bernard, Supervisor of Man- “a Arts, Salida High School, Salida, olo. Science is a living, vital subject. If one teacher more than another should be up to date it is the science teacher. I think that PopuLar SCIENCE MONTHLY is the best magazine on the market for supplementary science material. Albert . Early, ene, High School, N. Plainfield, N. J The PopuLaR ScIENCE MONTHLY taken by the school is literally read to pieces by the first year and third year pupils. It is referred to very fre- quently in class, and is of material help. . B. Roote, Headmaster, High School, Northampton, Mass. The PorpuLar SCIENCE MONTHLY is the most popular of all magazines, especially with the boys of the 8th- gth-1oth years (highest grade and first two high school years) in school. Burt W. Alverson, Principal, High School, Dexter, N. y. Fighting Off Submarines with Armed Buoys 9 — = ees =e _. = Electric light Wireless and wireless mast - Mast folds down with closing fy of hatch poh ; Gasoline engine and air 7 compressor in water-tight 3 Rapid-fire gun, compartment Telescoping periscope Water-tight am munition locker a Valve to let out, compressed ¢ air in submera# Sy fos) Waive and "oy compressed’ ater-t air infet to , NS force water if} sybian iho CompressedJair tank ‘Telephone wires / to trunk line,tele-/ phone cable to | shore base —— ‘Signal flags~ Towing line % 4 y drum Dry battery ‘Net support f Weights on bottom rods } The Submersible Buoy and How It Works As soon as the submarine strikes a light net, held in the water by bamboo rods, a telltale flag appears on a little float by day and an electric light flashes by night. The lookout on the deck of the buoy knows that a submarine is near. At once the wireless outfit is brought into play to notify a patrol. If the buoy should be attacked, the crew go below, open the sea-valve, sink out of sight and telephone to shore telephone - 642 _ Popular Science. Monthly 239 Fourth Avenue, New York City Vo OL a November, 1917 $1.50 Annually The Gun-Buoy for Repelling Submarines It has living quarters for four, telephone connections, periscopes and a rapid-fire gun—all the modern marine conveniences SERIES of huge buoys, each of A which carries a gun and on each of which four men can live for many days, is the latest solution which has been offered to cope with the submarine menace. As the picture on the opposite page shows, each: buoy has an upper deck on which a three-inch rapid-fire gun is mounted, living quarters below the gun- deck, a “tank below the living quarters, which tank is to be filled with water in : 0 nk the buoy, and finally, a cylindric © ‘compressed- -air tank at the bottom. >The buoy itself is about sixteen feet in diameter and about twenty feet _ deep from the gundeck to the top of the compressed-air tank. At the bottom of the compressed-air tank is a cable drum and winding gear. The anchoring cable is wound around this drum. When the buoy is to be rapidly submerged, its sinking can be hastened by winding up on the drum gear, the extra downward pull assist- ing the water admitted into the submer- gence tank. A hand gear is provided in the living quarters to facilitate the winding up of the mooring cable. The buoy is equipped as completely as a boat or as a submarine itself. It has a periscope, which can be used when the gun deck is just awash; a wireless outfit; telephone connections with a land station; a microphone for picking up the hum of a submarine’s motors under water, and a small gasoline engine. with attached air “compressor, which is stored in a watertight compartment and which serves the purpose of filling the compressed-air tank. A whole series of these buoys is to be used. They are connected by a telltale net of very light construction, the meshes of which are about twenty feet square. The nets are to be made in units measuring forty feet by two hundred. Light bamboo poles suspend the nets in the water, the bottom pole being weighted so as to keep the unit upright. The upper bamboo pole is connected with a little float which is shown in the detail drawing on the opposite page. . The float carries a telltale flag and an incandescent lamp, the one to be used by day and the other by night. As soon as a submarine strikes the net, the flag is. thrown up and the light flashes. Each little float is attached to the top of each net unit. The connection between the float and the net is such that the slightest tension upon the part of the net will destroy the connection. - A line leads from the net unit to the little float through a watertight tube and to a drum on which it is reeled. As soon as the submarine strikes the net unit, the float rises and the line is unreeled. When the whole line is unreeled a latch attached to the drum is released and that, in turn, unlocks the flag, which is forced up by a spring. The pole of the flag throws a knife switch so that the battery is simultaneously placed in circuit with the electric light. The buoys are in direct communication with one another as well as with the main- land and the patrol fleets so that they are able to give instant warning of the presence of a submarine within their radius of action. Normally each buoy would float just above the surface with its hatch open. One man would be stationed on deck as a lookout; another would operate the wireless apparatus; a third would stand ready to perform any necessary operation; a fourth man would be sleeping. The cost of making the buoys and net units is small compared with the building of destroyers and submarine chasers and steel nets. Moreover, they can remain at their stations for a far longer period than a patrol fleet can remain at sea’. 643 644 A Merry-Go-Round with Which Ger- man Soldiers Amused Themselves ROUND the world in forty days,”’ is part of the legend which appears over a ramshackle merry-go-round made by the Germans on French soil. Forall we know, this may have been the Ger- man slogan at the beginning of the war. The merry-go-round is now in the possession of the French. Two cast-off wheels with the axle form the main part of the makeshift affair. The elaborate _ structure on top is agiant spoked wheel placed over the ordi- nary wagon wheel. The seats are suspended by wire— rope being as scarce as copper. French eka Photo A German merry-go-round cae out of odds and ends on French’ territory and later abandoned Keep Livestock Away from Railroad Tracks and Conserve the Meat Supply URING the twelve months ending June 30, 1917, the Southern Rail- way system alone paid out.more than $200,000 in judgments to farmers for © ~ animals killed on the railroad’s right of way. President Harrison, of that system, points out that if the farmers would prevent their animals from straying over the tracks they would help solve the war problems. In the » first place, the animals ‘killed: are a total loss as far as the food supply is concerned. Then, the sum paid by the railroad in recompense even at the present prices of equipment, would buy more than one hundred standard box cars capable of handling’ at a single load more than 3,000 tons of freight, thus tending to relieve:the freight congestion. Here, then, is a chance not only for the chuck- ling farmer but for the comic artist and the jokester to relinquish a source of income for patriotism. Popular Science Monthly § The Suitcase Talking-Machine. . Take It Along on Your Travels HAT to do with the talking-machine when you leave the city for the summer has been solved by Arthur Stech- bart, of Chicago, Illinois. Like the dog, the cat, the pet parrot and your wife’s new hats, you take it along with the rest of the hand _ bag- gage. Being a portable ma- chine in the shape of a small suitcase, it can be carried from place. to place without injur- ing the mechan- ism jor destroy- ing :the records, _which..do not ‘have. to. be car- ried . separately Ai is packed away withing th machine itse Brass knobs protect the corners pee add to the suitcase appearance of the closed machine. The handle of strong padded leather is placed just exactly as it would be on-a.regulation suitcase. “But the interior is exactly like that of the small-sized talking machines. The record chamber is on the under side of the hinged cover of the machine casing. “A recess is cut into the top board of the casing to Record storage compartment The talking-machine is a small- sized suitcase, with a chamber in the cover to hold records hold the needles and needle-carrier. . Popular Science Bi crtkly 645 A Perfect Bread Slicing Machine for the Commissariat NEW bread-slicing machine re- cently devised by two Washing- ton men—W. H. Garlock and W. J. Stubbe, of Seattle, slices an entire loaf at one operation without crush- ing, tearing, or breaking the slices. A number of knives, supported in two frames, are operated vertically and simultaneously but in opposite directions. When one set of knives is traveling up, the other set is travel- ing down. By this arrangement the friction in the slicing operation is counteracted and the softest and hardest baked loaf can be sliced equally well. The workman operates the knives. by pressing on a treadle. A second operator at the rear or side of the machine then moves a lever that operates a mechanism that ejects the slices of bread. Meanwhile a release of pressure on the treadle permits a weight ‘to restore the carriage of the machine to its initial position, and a plate is automatically drawn from under the slices, allowing them to roll into a recep- tacle beneath. When delicate cakes are cut the slices are lifted out by hand. The bread slicer is operated by a treadle. A whole loaf is cut at one operation To a submarine a few miles distant, the ship above seems to fade away into a glittering, shimmering haze! A Leopard Ship of the Sea—Even the Masts Are Spotted OOLING the enemy is a remunerative and interesting pastime with the Allies. They have their camouflage on land; now comes the camouflage of the sea. A ship is painted with spots which fade out into a glittering and shimmering haze in the sunlight. A submarine commander one or two miles distant might look straight at the ship and never see her. The spots are of light gray and navy blue, which, even on a sunless day blend with the waves of the ocean. The indistinct outline which this gives makes the ship a poor target. Fat People Are Unpatriotic. Give Up Your Fat to the Nation CCORDING to statistics compiled by the Life In- surance companies, there are, between the ages of thirty-five and fifty-five years, a vast number of people who are hoarding and accumulating fat enough to supply energy equivalent to that of 690,355,533 loaves of bread, enough to supply an army of 3,000,000 men for sixty days. A man who is forty pounds overweight is carrying on his body the equivalent in fuel value of 135 one-pound loaves of bread. If the guilty ones would cease this accumulation (which they are willing enough to do) it would release much-needed fuel foods, such as wheat, corn, oats, barley and rye. There are two ways of surrendering this fat. One is by judicious exercise and the other is by substituting other foods for the fat-building kinds. Your campaign hat serves as a lining for the steel helmet shown at right. It can be removed and used as a tool in an emergency A Versatile Helmet. Take It Off and You’ll Have a Shovel HEN Leonard D. Mahon, of the Washington, D. C., Detective Bu- reau, designed a helmet with a detachable lining he had more than a helmet in mind. Unfasten his helmet from its lining and take it off. Behold! You are still wearing a hat—the regulation’ campaign hat, upon your head. The campaign hat is itself the lining! The steel shell you may put to any of four unusual uses. If you should be pressed hard by the enemy, you can, as a last extremity, employ it as a hand spade and intrench yourself in a rifle pit. If you are on the march, on .the other hand, it will serve you as a wash basin for face and hands or for your tired and aching feet. Especially will this im- provised basin be nec- essary when you come to a stream where you may take a much- wanted drink. In camp, the versa- tile helmet will make a good water bucket, or it may beused for bailing. 4 You can make a per- fect cigarette in a blow- ing gale with this de- vice without spilling a particle of tobacco Bopuls Science Monthly Cowards in the Army’ Are Ravi! Some Are Merely ‘‘Deficient’’ ANY a man is mentally unfitted to stand the strain of war. In ordi- nary civil life he would be able to do his duties successfully but under the stress of modern warfare he would col- lapse. Considered a coward he would not in reality be responsi- ble for his actions. In order to weed out men who are unfit for the work of the war a unit of thirty beds will be attached to ‘each base hospital in the training camps. The men assigned to these beds will be those accused of cowardice by their mates: They will’ be under the watch- ful eyes of physicians trained to detect signs of. mental weak- ness. Those who show such signs will be rejected. This will save many men from _ severe punishment for cowardice and weed out the unfit. = sated : The. Mechanical Cigarette-Filler. It Supplies Its Own ‘‘Makings’’ OT since the first safety razor’ has there been — any novelty invented which gets so close to the ‘heart of a nian as this mechanical cigarette-filler, invented by Dr. Edward P. Delevanti, of ‘New York city. The device is a pouch | ‘made of nickeled steel or strong leather, in which rice paper, tobacco (your favorite brand) and matches may be kept. At the bottom of the pouch is a groove-like arrangement into which just the proper amount of = tobacco slides down into the rolled paper, which you hold in position to be filled. A metal plunger, or ram- mer, packs the tobacco in the paper roll. “Gutker isk 3 saintly _- Lamaism is a form of Bud- Popular Science Monthly His Drum Is Made of Human Skin and His Trumpet of a Thighbone AMA, meaning “a su- _4 perior one,”’ is the name given by the Chinese and foreigners generally to the Buddhist monastic order in Tibet. In Tibet, however, the word is reserved for the monks who have not only taken the highest theological degrees, but who have led lives and become famous for knowledge. dhism practiced by the peo- ple of Tibet. In lamaism, magic and mysticism play such a commanding part that its relation to Buddhism can be recognized only with difficulty. The monks of ‘Tibet are believers in the efficacy of prayer. They use a rosary such as that worn by the lama in the photograph. The rosaries are made of various kinds of wood, shell, sections of human skulls, and various kinds of odd seeds. - The drum and small trumpet shown in this picture are used in | ceremonies connected with the exorcising of evil spirits. The drum is usually made by joining at the tops the domes of two human skulls, the drumhead being made of human skin. The beaters are suspended from cords and the drum is sounded by smartly rapping the beaters with the hand against the drumhead. The small trumpet is made from a human thighbone. Among the most important objects used by the lama in church ceremonies is the vajra, or thunder- The lama with his ceremonial outfit which he uses in exorcising evil spirits 647 of power, the vajra, or thunderbolt, which was appropriated as a trophy by the victor, and has ever since been adopted by his follow- ers. The usual dress ofthe lamas consists of a kilt reaching down to the ankles, a close-fitting waistcoat, and a shawl passed around the bedy leaving. the right shoulder and arm uncovered. The head is shaved, and no head- covering is worn except in church ceremonies, when a high yellow hat with a fringe such as that shown in the photograph, is worn. The Favorite Pocket- Knife of the Jackies. ItIs a Century Old CCASIONALLY we come across some article of manu- facture which has been im- proved upon year after year, only to return again to its origi- nal state as the most desirable. This is true of the pocket-knife. You will find it in all de- grees of perfection and ornamentation, but the style most approved at the present moment is that of the old navy knife—in- vented no one knows how long ago. This knife is shown in the accompanying illustrations. It is the instant action, drop- out type, and is made in two styles, either of which the jackie prefers above all modern pull-out and push-button types. The blade simply slides in a groove so that it is opened by the same movement which jerks it out of the pocket. bolt, which is the small metal object at the left elbow of the lama in the photo- graph. The Napa- lese scriptures say that a contest once occurred between Buddha and Indra, in which the latter When it has been fouled from long usage, the entire blade can be taken out and cleaned. The jackie prizes its simplicity when he is up aloft, with only one hand free, and when his fingers are stiff and numb. was defeated, and had wrested from him his chief and peculiar instrument Two types of old-fashioned knives which are more popular with the sailors than any modern specimens At such times any other kind would be useless. ; r er + Wf A Uy RQ NTA This figure,-the one- arm back lever, is easy for James Gleason, the national champion on the flying rings.- But you’d better not try it until you’ve practiced Below: Here: we have the one arm hand stand. Both rings are used and the weight is thrown on the arm that grasps the rings a Chips ig Ce Wrap yyyyyyyyy lll 4 TA a q Oe i te ; Ge Lh id dss ldlddddee Le The front rest. . Both arms are used and the body is raised and held perfectly rigid XX ss XX tea WOW AAA —- < Thisis a graceful pose, but difficult. Gleason is supporting his weight on his spread arms. This is harder to do than the straight hand stand 648 The two-arm front lever. The weight is borne on one ring with both arms. The trick lies in balancing the body with the arms at the angle shown here Below: Gleason is looking pleased, prob- ably because-he knows he can do the back lever so much better than the rest of us can play, Poses Obligingly for Our Admiring Readers - 8 ee da dus, Here is one you'll have to practice hard to master. One man is sup- porting himself on two rings through which he has thrust ‘hisarm. The other man is doing a hand stand on his arm When you get to the point where you can do easily the shoulder stand shown below you will know you are getting on. In this you can’t depend on your’ hands SS SS ~ 4 < re ciate ye ee ee ee ES See eo Sin) . This is the difficult double lever. Onc performer does the usual back lever while another suspends himself from a towel around the first one’s neck 649 This trick, which is thehand stand, calls for fine poise. The rings and ropes are likely to move at any moment. Itis only by clever bal- ancing that this pose can be held even momentarily There Are Many Ways of Picking Up a Living Like the vendor of Seville pic- tured on page 654, the milkman in Chili doesn’t bother about a wagon to deliver his milk. The milk cans are carried in sacks over the horse’s back and the milk is measured out with a dipper straight from the can to the consumer. ‘In some parts of Chili the donkey takes the place of the horse as a milk-carrier When W. C. Grant lost his arms braking freight in the West Buffalo freight yards he forgot about misfortune and became a street musician. He had a special instrument made for him, consisting of pipes mounted on a metal support. By binding the stumps of his arms with cloth and by rubbing rosin on the cloth, he ‘was able to extract music from the pipes. He has played in the streets of all the big towns from coast to coast ; e . | * Two Massachusetts boys wash- When a steamer heaves in sight near Jamaica it is be- ing out riches, but the mineral is sieged by native traders who are anxious to dispose lead instead of gold. A gun club of young monkeys that have been trained and shoots over the mud flat and the birds of brilliant plumage for a little silver. boys collect the shot from mud They approach the ship in canoes and small boats 650 Without Actually Working—Take: Your Choice t x. Pre ae a LEP AROLE EEL RLM MRA Me ae ae RAN, Negro: divers of the West Indies. Throw \ fifty centsintothe water ' and they will dive down -and get it out of the glistening sand into which it falls, swim- ming clear under. the ship and coming up on the other side to inveigle you into throwing another In Caraccas they sell lot- tery tickets like postage stamps. Once in a while somebody is allowed to win John B. Riley, of Lancaster, Pa., playing on two instruments at the same time. He is 75 years old. and makes a good living 651 Steeple jacks will tell you that they don’t take chances; they let the other fellows do that. Here one is disentangling a flag twenty-one stories above the street. Be- cause their work in- volves such danger their pay is high The portable oven vendor of the east side, New York, who can sell you a hot meal for a few cents 652 ' Popular Science Monthly “Poor chapi You can’t see very far?” A printed card was shown him, twenty feet away. ‘“‘I can read only the first line.” They moved him up within ten feet of a mirror and placed the printed card just over his chest as shown below. ‘‘How many lines can you see distinctly ?’’. He could read a number of letters now. ‘‘You are taken,”’ was the verdict. He read the reflected type at exactly the same distance from which he said he could not read in the first test, for- getting that the re- flection doubled his reading distance MMU UM DOLL ae He is trying hard to be deaf. A careful record is made of where and how he can hear : the tuning fork. ‘Then they te blindfold him and, expect him to give the same answers when asked again. Hard lines! He can’t do it IOAN WD D4 0 6 *t™® = " “Arm hurts?” says the doctor. He blindfolds the slacker, marks the supposed sensitive spot with a pencil and then squeezes ‘the arm in several spots. Never a whimper. Where there is no pain, ‘the orly way for Algie to tell when to scream is by looking at the doctor when the supposed sore spot is touched. Blindfolding him took away his only chance The Way of the Slacker He Is Beset with Ingen- Which He Is Sure to Be “LALLA OOOO | Sn SR SN . SSNS EIENENONOEIRUUNESONENUE Couldn't see with his right eye at all, said “T’ve got sciatica something teriible.;’ They made him take Willie. The doctor befuddled him so with off his shoe and sock and stretch out his leg. That was enough. a two-color glass that before he realized it he No man suffering from sciatica could do it. He literally put was reading a card with his poor blind eye his foot in it and is now marking time to the music Popular Science Monthly He said that he couldn't hold anything in his ngers. ‘‘We'll sp yr o oI ° = < By) mn VLE. verdict. ‘‘Look at the nicotine stain. You can hold cigarettes, and so you can hold a rifle” One arm and one side com- pletely paralyzed—so he said. He did not know that there are electric reactions of the mus- cles. The little electric battery on the table in the pic- ture below betrayed him xy LLL Batioine “I’m lame in one foot. Can’t walk without a cane,” he pro- tested: The doctor boosted him up on a chair and looked at his heels. They were both worn down exactly alike prov- ing that both feet were normal WA EW Www 0 5" FE Ue “I'm, deafin :the left ear.” The doctor plugged up the right tube of a stethoscope and asked Ctto if he could hear the watch ticking. He could. “You hear it:-with your deaf ear,’’ said the doctor. And sothe army got him Is Hard. Everywhere ‘ious. Medical ‘Traps in Ensnared and Betrayed 3 x TRON SOS S MMNMAAAGAA SSSR “‘Something’s the matter with my heart,’ protests the He said he was deaf. They dropped an iron chair, slacker. The doctor takes his blood pressure. The He never moved. “You are faking,’ said they. heart action is perfect.. Another slacker goes to France “A deaf man would wmp from the vibration” Baths Without Bathtubs and Milk Without Dairies A be-soaped Ceylon youngster getting the bath that has probably been promised him for fully The mother takes a bucket of water and a cake of soap and does the job quickly and thoroughly right in five months or more the middle of the road In Seville, Spain, they never bother about certified milk when they can get it delivered to their doors, warm and fresh from the cow herself. After she has yielded her daily quota of milk the cow is led to pasture for the remainder of the day. The milk is sold by the glass, pint or quart. Note the measuring cup behind the ears 654 Ancient Cliff Dwellings Near Santa Fé SHUM AAW Recent excavations in the Canyon del Rito de los Frijoles show us how cliff dwellers lived. Quanti- ties of curious specimens of pottery were: found A village excavated in the Canyon del Rito de los Frijoles near Santa Fé. The dwellings are arranged in the form of a horseshoe about 115 feet in diameter Modern Russia’s Joans of Arc. All Classes Are Represented in the Regiment of Women, “From the Colonel’s . Lady to Judy O’Grady” Amazons of the Battalion of Death re- ceiving caps. Each girl carries potas- sium cyanide which she will take at the last moment rather than be captured RSS Ye fi, Ad Wh VM dllddllldl Uda Vldddl N Photos © Int. Film Serv. Like their brothers, in arms Russian girl soldiers must have mascots. Short hair and masculine clothes can’t eliminate a feminine fond- ness for cats and birds a, ye eee | Women warriors learning the business of warfare under drill-masters!) from the Guards. Their stoic bravery under fire is one of the wonders of the war SSSA SSS SENSES 656 Shooting Irons and Buoys to Save Your Life “capresso Photos@©@ Int. Film Serv. A sharpshooter wearing a water jacket used by British Tommies when fording streams. He is able to use his rifle without getting it wet. If he can tread water one man wearing this life preserver can easily support six men ONE on osesipesnacomcg A soldier who cannot swim may still be happy in the water if he wears this new life preserver. He. can shoot with both hands and smoke besides. He knows he won’t drown Blowing up the water jacket. When deflated it takes up very little room and weighs only one pound. It will keep a man afloat indefinitely Making the Phonograph Work e “ Wedd ddiddJsyyyddidddddddddediidHddddddddddddidddd Below: Music history at Ann | x cc -. Arbor was always a pretty dry subject until the instructors hit upon the happy idea of illustrat- ing their lectures by phono- graph. Now no one cuts that class DV WS RRRRAWWWWwWw-Fe=71WWF=E'Feé?>—*=F?é™7. FEF #P®5pBhHtlwWwO WWW MOO BMAAANN SS N As for recruiting, that’s where the phonograph plays a star part. Just look at the crowds listening to the phonograph—-and the orator—of the LK Below: Dumb-bell exercises get under way with lots more vim when the phono- graph plays. This picture shows modern ideas in prac- tice at Waynesboro, Pa. Above: An English army officer dis- covered that in- corrigible horses may be made tract- able by music. The photograph shows a group of “bad uns’”’ getting in good humor by listening to the phonograph 658 _. The Inspiration of Canned Music Out in Rutland, Vt., they teach stenographers to typewrite to music. They get up more speed to the tune of a popular song than they ever did to an unpopular’ dictation lecture Recruiting Station at Fifth Avenue and 42nd Street, New York. When the boys heard those patriotic airs they just couldn’t help joining At a recruiting meeting in charge of Captain Rees, of the Royal Fusi- liers, held at Trafalgar Square, London, a pho- nograph uttered all the Cows enjoy light opera. Play their favorite selections at words of command milking time and you’ll get a freer flow of milk as a reward 659 Recently Mr. Philip Gibbs reported a thrilling fight between a German airplane and a British tank. Of course, the airplane had the worst of it, for the tank was armored and impregnable to machine-gun bullets That the tanks are irresistible is demonstrated by Mr. Gibbs’ account of the calm way in which one of them knocked from its rails a small locomo- tive which happened to be in the way 660 Airplanes in This War of Terrible Wonders “There was a boy of eighteen in one of our airdromes,”’ writes Mr. Philip Gibbs, the war correspondent. ‘‘His first adventure was with a German motor car with 3 two officers. He gave chase, ... and followed. Then he came low and used his machine gun. One of the officers fired an automatic pistol at him, so the boy pulled out his own revolver. There followed the strangest duel between the boy in the air and the man in the car. The airplane was fifty feet high then, but dropped to twenty just as the car pulled up outside a house. The young pilot shot past, but turned and saw the body of one officer being dragged indoors” Who’s Who and What’s What in the Army PSO DE eC el oe BBV Proren oY 1—Infantry Insignia 6—Signal Corps 11—Dental Corps 2—Cavalry 7—Aviation Section 12—Veterinary Corps 3—Field Artillery 8—Ordnance Department 13—General Officers ¢ of the Line 4—Coast Artillery 9—Quartermaster Corps 14—General Staff Officers 5—Engineer*Corps 10—Medical Corps 15—Adjutant General’s Department > >< >< >< > o ~ | 2 ee | 2 3 \ 2 7 =o Infantry Divisions Infantry Divisions a Infantry Divisions ist Army Corps és and Army Corps Z 3° Army Corps i Ar my PR tetas lk PRS re OMe © <—__>}<___>}<-_—s}x-__»>j | The War Department an- ] a 3 40 2 3 4 i 2 a 4 nounced recently that a Companies - Companies Companies change was to take place > > > in our army organization. ’ 2 2 The large units of th: old i - organization were too un- Battalions wieldy for trench warfare and they have been broken - Infantry Regiment ' We now come to the subdivision upon which the entire theory of army organization is based. It is the infantry regiment which advances and wrests contested territory from the enemy. The other arms are subordinate to the infantry and are built up only with an eye to assisting the infantry in these tactics in any way circumstances may suggest. The battal- ions making up the infantry regiment are in charge of a major Company At the bottom of every army is the private, and the group of six or eight privates which make up the squad. No group of - men can be together without one of them being responsible. The corporal, who is simply some designated soldier in the squad, is a general leading a small army. He in turn is subject to the orders of the platoons commanders, who are lieutenants and sergeants. A captain commands the company The automobile has had a tremendous influence in making present-day warfare as mighty as it is. Supplies: are now brought up in great motor-trucks four times faster than they could be with army mules 662 up into smaller ones, more flexible and easier to command. This explains the new army corps unit in the present system \ 2 3 Ss 5 Shoulder straps which commissioned officers wear: 1. General; 2, Lieu- tenant General; 3, Major General; 4, Brigadier General; 5, Colonel; Who’s Who and What’s What in the Army 16 17 18 18 16—Inspector General’s Department 17—Judge Advocate General's Dept. 18—Detached Officers 19—Additional Officers 20—West Point Cadets 19 19 a 20 21—Philippine Scouts 22—Indian Scouts 23—Recruiting Service 24—Recruiting Depot 25—All Army Troops eve 6OoAAmm 26—Service School 27—Disciplinary Barracks 28—Disciplinary N. C. O. Instructors 29—Sergeants (Corporals, two stripes) 30—Reserve Officers Training Corps >t< *——>* <——> < he < >_> >< ca, = 3. |Trench} ! 2. |Machine| ! Machine} | 2 ae eae >| Mortar]. Cun. t 5} Gun Regiments Battalion) Regiments Battalion) Regin.znts Battalion Companies Field Artillery Brigade \st infantry Brigade e°. nd Infantry brigade Machine Gun Battalion The former infantry division of nine regiments of infantry and three of artillery has undergone the most change. Five infantry regiments have been cut out and machine gun and trench mortar battalions have been added, so that the artillery strength has been increasedconsiderably. ‘fhe division, which once consisted of twenty-eight thousand men, has been reduced over thirty per cent. The Army General’s Staff control brigades and regiments Infantry Division 6 7 8 9 6, Lieutenant Colonel (in silver); 7, Major (in gold); 8, Captain; 9, First Lieutenant; 11, The Chaplain 10, Second Lieutenant; 10 663 The work of the signal corps is ex- ceedingly important. ‘The men of the wireless service follow the infantry in their advances and keep up the com- munication with the army headquarters Modern armies are complex organisms, not so much because of the large organi- zation of field forces, as on account of their many needs. Hence the necessity for a reliable transportation system No matter of what service or what rank, every Ameri- can soldier has an equal chance of winning the Medal of Honor. It is awarded by Con- gress for. distin- guished personal bravery or self-sac- rifice that involved the risk of life. It is even more diffi- cult to obtain than is the Victoria Cross “664 Popular Science Monthly on each floor. & ee They are so fitted that Ger The glass-lined, st@el laundry chute for use in hospitals and hotels. At right is shown the ventilator at the top, the plateglass-covered openings on each floor, and the cellar exit Sending the Wash to the Laundry Through a Glass-Lined Chute NEW type of laundry chute has been designed for the use of hospitals, hotels and other institutions where large quantities of soiled linen are handled. It is constructed of steel with a fused-in lining of glassenamel. This lining is particularly de- sirable because it is rust proof and will not absorb substances or odors. The chute is supplied with a flushing ring , at the top so it may be thoroughly and easily cleansed by a shower of hot water. An outlet through the roof permits ven- tilation. The chute may be aired by opening the bottom door which allows a strong draft to blow through it and out through the ventila- tor. Plate glass and nickel doors open out Perforated cover Steam ducis/ es wee nee 4 Automatic ball f teat A machine that keeps the air in the house as moist in winter as the outdoor air in summer are airtight and prevent the escape of odors and infections while the chute i is in use. A Machine that Moistens the Indoor Air (Fz of the greatest objec- tions to artificial heat is the fact that it tends to make the atmosphere very dry. A certain amount of moisture is necessary to maintain health- ful living. conditions. When the atmosphere is sufficiently moist a temperature of 65 de- grees is more comfortable than one of 70 degrees, and at night, when the heat is off, the house will not become as cold as it will when the air is dry. A device has been perfected _ which will keep the house air — . moist. This is a receptacle which holds and evaporates . water in such a manner that the moisture will be diffused m® into the air without > condensing. The apparatus measures about 20 inches in length and nine inches in height. It will evaporate three and one-half gallons of water during a day and an evening. This quantity of © water maintains a humidity of 45 per cent in an ordinary residence. L The device may be connected with the water pipes and heating pipes of a house. The water supply is automatically regu- lated and the water is heated by the heatin 2 system. The apparatus may be used wit steam heat, hot water or hot air. The heating and water supply pipes are provided with valves so the moisture may be turned off. at will. If the air is sufficiently humid so that it is not nec- essary to supply it with moisture, the machine may be used as a small radiator. This is accomplished by turning off the water supply valve. It will then give off heat without releas- ing moisture. ennai Water feed pipe - [Fels a . a 4 4 = Wy _- The inventor fails to tell how this man could inhale enough air to raise’ a snore if the strap were tight enough to hold the ballin place NFORTUNATE — because innocent —is the person who snores. But let him take heart! Science is on the job. The activities of the geniuses who would silence the snore have been wide- spread; their devices for restoring peace on earth and sleep to men take many forms. The amount of thought that has been given to the subject is amazing, and we may infer that many a midnight watt has been. consumed in the search for a snore-silencer. : _ As the poet might put it, the triumphs by these workers scored were not attained by sudden . flight, but they, while their companions snored, were toiling onward through the night—obviously not ‘the oft-mentioned stilly night, else the incentive to work would have been missing. The specimens of anti- snore devicesshown here are separated into two classes. The first principle em- ployed, as the scientific foes of the snore would apply it, may be described as_suffo- cation in varying degrees. Exhibit A-in the center of this page is the simplest type. It is a modification of the idea that if a man can’t breathe, he can’t snore. Specifically desig- nated, it is a plug for the mouth. It consists of two Valve Any snorer who defied this anti- snoring plug clamped mouth would do so over his own dead body, so to speak; that is, he would be suffocated in the attempt This apparatus has a tether which prevents it from get- ting lost in case of a blow-out Filtering the Snores Out of Sleep How our inventors are wrestling with the problem of silencing the nasal nightingale By E. B. Breuer soft rubber flanges connected by a thin rubber strip, which is to be held between the teeth. One of the flanges is to be placed behind the lips. The other remains outside. The flanges are bigger than the mouth, and the device when in place thus constitutes an effective stopper. As mouths differ greatly in size, we assume that this is essentially a tailor-made device. The inventor leaves us in the dark on that point. We must agree with him, however, that to the-man who consents-to wear one of the appliances, nasal music will become a lost art. : : The inventor of the similar device in the center of page 667 is more lenient. His ap- paratus also is a stopper for the mouth, but it has a one-way valve. The valve, opening outward only, permits the expul- sion of air from the lungs. . Should. the wearer .at- tempt to inhale through the mouth, he will find himself surrounded by an. utter lack of facilities for such an operation. In such a case the valve closes instantly, the sleeper is obliged to inhale through the nose and another shat- tering of the silence is averted, or, as the inventor: scientifically puts it, there is an ~ absence of ‘‘the harsh nasal sounds commonly called ‘snoring.’ ”’ It remained for a Wis- consin investigator, whose device is illustrated at the bottom of this page, thor- oughly to tame or domesti- cate the anti-snoring shield. - His apparatus is‘ supplied with flanges—to fit under the upper and lower lips. They are to keep the device from wandering from side to side. But the striking feature is a ring which pro- trudes from between the in his 665 666 lips when the device is in place. A string attached to the ring can be tied around the neck. This will enable the wearer to recover the shield in the dark in case he has a blowout. It will also keep him from swallowing or inhaling the apparatus should he overcome its resistance by a determined effort to break into nasal rhapsodies. In the second class, the anti- snore devices are intended to keep a person from sleeping on his back, in which position the nasal soloist makes the welkin and adjacent hardware ring. Apparently the inventors who work along this line never slept on lumpy mattresses. If they had, they probably would have directed their thoughts _to- ward some method of fastening the snorer, face up, on any one of the inani- mate deformities of the bed. In one of the illus- trations at the bot- tom of this page is a simple application of this principle. sleeper off an even ~keel. The pad, says the inventor, will keep him always listed either to port or to starboard = > ae € It may be confidently stated that the wearer of this device would not snore for the simple reason that snores accompany sleep and for him sleep is altogether out of the question Here some mercy is shown. The ball is pneumatic. ventor emphasizes the importance of protecting it from puncture Popular Science Monthly shoulders. He advocates the use of a rubber pneumatic ball to be fastened to the belt in such a manner that it will be neither punctured nor displaced. He fails to explain how a person with the belt — strapped around his chest tightly enough to hold the ball in place could in- hale enough air to raise a snore. In that, however, may lie one of the subtle and fundamental excel- lencies of his invention. The genius responsible for the device illustrated at the bottom of page 667 goes his fellow scientists one better. He doesn’t believe in half-way measures and is not afraid to say so. His scheme is to make life on the flat of the back so miserable thata snorer assuming such a position will wake up at least long enough to wish he had never been born. Incidentally, he combines a shoul- | der brace with the snore dispeller. The connection between snoring and shoulder braces is not imme- diately apparent, but it becomes so when one reflects that if a shoulder pee won’t keep a Peres awake, nothing wil The refinement of torture, however, so far as this public benefactor could apply it to snoring, is embodied in the attachment to be fastened to the shoulder brace at the back. The attachment is a metal casting having several projections. Though spikes. But the in- as gi ar = = 5 Be el kal ea le AO SER Te Og ee Tt ee to be tipped with balls or knobs “to prevent them from injuring anything they come into contact with.” He frankly admits that the attachment is a “prodding device,” and declares it will prevent snoring ‘‘by prodding the wearer in the event of ly- ing on the back.”’ ' The combined brace and prodder could be used by _ day, as well as by night. “The prodding device could be worn with the inventor ex- “and would serve to remind the wearer to straighten up in case of a ten- dency to lean forward, thus pre- the brace at all times,’’ plains, ‘venting too great dependence upon the brace itself for sup- port.” On this point there seems to be no room for argument. In addition to these many advantages, this appliance might have another use, on which a tip is offered to the inventor free of charge. — In the privacy of his home, if the metal pro- jections were a little longer than indicated beyond the power of the writer. Popular Science M. _— undoubtedly would be more effective, the inventor seems to have been overcome bv _a feeling of pity at the last moment, for he directs that the projections are Here is a real masterpisce. The device, turned one way, will completely silence the snorer. Reversed, it allows him a little musical leeway Flap valve Through this one-way valve the snorer exhales through the mouth if he wishes, but there mouth- breathing - option ends in the patent application, the wearer might use the prodding device as a hat rack and clothes hanger when he is not in bed. A California man has invented what may be called the anti-snoring shield deluxe. It is illustrated at the top of this page. Ade- quately to set forth its many special features, ex- tra attachments and added attractions would be no mean job for a circus press agent. It seems doubtful, however, whether anybody except an engineer ever could learn to wear the thing successfully, because of the complicated valve system by which it filters the snores out of slumber— or graduates them to suit the ear in the event that limited special privileges . sleepers or elsewhere. i The man who devised this apparatus has probably suf- fered many things in Pullman He has not the least compas- sion on anybody who snores 667 are accorded to the wearer by his victims. Despite this, consistency common to genius, contends that ‘‘the object of the invention is to im- prove, simplify and cheapen the con- the inventor, with the in- struction of the device by providing the flexible mouth- piece with a _ plurality of valves for controlling the vol- ume of air expelled from the lungs through the mouth and for controlling the admission of air throxgh the opening in said mouthpiece when the latter is reversed.”’ A technical description of the device is It seems, though, that the inventor has tried to puta new interest into life for the snorer by adding to the valve scheme a means of regulat- ing the size of the opening through which air is inhaled:or ex- pelled, according to whether the shield is being used as a snore sentry or as a safety valve. The regulating is done by means of a little - metal clip which is slipped over the edge of the valve seat and raised or lowered like the floodgate of a dam. We assume that instruc- tions as to how to operate the mechanism will be given with each device sold. 668 Popular Science Monthly This Electric Heating Faucet Has No_ A Space-Saving Display Fixture Which Switch or Coils N electric water-heating faucet, just placed on the market in California, differs from other devices of this kind in having neither electric switch nor coils, the water itself serving to close the circuit and to supply the resistance for heating. The device is so made that cold, warm or hot water, depend- ing on the position of the handle, issupplied instantly. The heating element, housed in the cylindrical casing that forms the top of the device, consists of an upright hollow car- bon cylinder enclosing a space in which is a graphite rod. These parts are insulated from the remainder of the device, and each is connected by an in- sulated wire with one pole of an ordinary lighting circuit. When the handle is turned to the ‘‘cold’’ position, the water flows through a by-pass without entering the heating element. When it is turned to the “warm” position, the by-pass is closed and the water passes upward between the cylinder and post, overflows at the top and passes downward in the space between the cylinder and cover. The cir- : cuit is closed by the water, thus doing away with the neces- sity for a switch, since no current can flow unless the heat- ing-element of the faucet is filled with water. When hot water is wanted, the handle is turned to such a position that only a small flow of water is admitted — just enough to allow it to be thoroughly heated before it reaches the outlet. Graphite rod In this electric heating faucet the water closes the circuit and sup- plies the resist- ance for heating 5a gauss al Also Saves Clerk Hire G ba display fixture shown in the photo- graph below will prove a money-saver as well as a convenience to the shop-keeper. It consists of a framework having a number of inclined drawers which may be drawn forward to hori- zontal position or sloped back- ward and up, so as to dis- play every article to the passerby. The drawers may be provided with hinged glass covers or left open as desired. When covered, they are opened by simply : raising and sliding forward the front part of the drawer. Customers may examine at leisure all the articles in the © various drawers without special attention from the clerk, so that one clerk may attend to several customers at a time. As the framework stands on a twenty - seven - inch base, two cases can be placed back to back so that articles can be dis- played to customers in two aisles at the same time. One clerk can serve two cases. In the drawers underneath the frame, heavier articles or surplus supplies are kept. In this way every available inch of floor space can be utilized. Moreover, the clerk, having his stock plainly marked as to prices and always before him becomes thoroughly familiar with it in little time. | Water iS Go Se amare) £6Gh\c2>: ee SSS AO CER ekg) Mocw aims | papnieimmiiag | = Wtfihhiiith— i | iithes| lee | BESS With prices plainly marked, the articles in this compact display case practically sell themselves. Surplus stock is kept in the drawers below Popular Science Monthly 669 The Full Dinner Pail. ‘It’s Built Like a Fireless Cooker THERMOS bottle will keep your coffee hot, so why not the thermos pail to keep your entire dinner at the proper temperature, whether cold or hot? By- ron Bruegger, of Wisconsin, thinks such a pail will be in so great a demand that he has taken out a patent on a design for one. The bottom of an ordinary lunch pail has an extra wall in it, around the outside of which the air. has been ex- hausted. In preparing for the day’s picnic, the desserts, the butter and the other victuals that are to be kept cold are placed in the very lowest chamber. A rather shallow chamber from which the air has been practically removed is provided on top of this cold chamber, and into this ‘‘vacuum’”’ chamber the meats, vegetables and the other hot dishes are placed. Over this chamber is a layer of asbestos. Then comes another hot food chamber. We have, there- fore, a poor heat-conducting medium surrounding the hot and the cold chamber and separating the one from the other. Little heat can pass either in or out of the cham- bers and the cold dishes will stay cold and the hot ones will keep hot for a reasonable length of time. Other dishes that are to remain at ordinary temperatures occupy the remainder of the pail. A neck is even provided on the cover-of this pail to provide a_ place for. a drinking cup. With such an arrangement an entire family on an outing’ could be sup- plied: with a dinner com- plete»from soup to ice cream and everything at the most desirable temperature. Asbestos layer The turntable is 14 feet in diameter. it is mounted in a pit at the edge of the turntable pit Everything from hot soup to ice cream can be put into this picnic dinner pail The motor operating Electrically Operated Turntables for Automobiles TURNTABLE that is operated by an electric motor, by means of a push button, is very valuable where the confines of the yard are so narrow that an auto- mobile cannot be backed out without risk of sidewiping the house or fence. The motor is controlled by means of a push-button hanging down from an arm so that it is within the reach of the driver of a. car when it is driven on to the turntable. The table is supported by wheels with roller bearings traveling on an iron track, within a pit. This iron track is placed out near the edge of the turntable. This arrange- ment keeps the turntable from tipping when a car is driven on or off of it. The motor is connected with a sprocket wheel by means of worm drive. A sprocket chain driven by this sprocket wheel extends around an an- gle-iron ring which is se- cured to the underside of the table near the per- iphery. This werm drive keeps the turn- table from skidding. The advantages of Separating wai! ivan such a device in a small Vacuum chamber C ‘| Cold food private garage and even chamberr in public garages where space is usually at a premium, are numerous and obvious. Vacuum chamber 670 An Accommodating Gas Stove. It Boils the Coffee and Then Wakes You GAS stove which arises at dawn, boils the coffee and wakes you up when it is ready, has been invented by Gemaro Rosa, of Brooklyn, New York. In order to describe the workings of this accommodating stove it would be necessary to use at least fifteen diagrams and seven- teen pages of this magazine crammed with text. For our busy readers we have boiled Gem- aro’s invention down to its essentials. It is an ordinary gas stove having a pilot-light to which is attached a clock mechanism. A dial over the clock- works serves to tell the time. A smaller dial is used to set the alarm, igniting and ex- tinguishing devices. When properly set, the burner under the coffee pot will automatically ignite at a pre-determined hour and boil the coffee for four or five minutes. The flame will then lower of its own accord for slow boiling for another five minutes, after which it will shut itself off entirely. The coffee is now ready for you and if you are not aware of it the trusty alarm will notify you of the fact. There is no possibility of the coffee boiling over unless you disregard the alarm and go to sleep again. Alarm = coaster or scooter can figure. Popular Science Monthly | Ignition set arm 5 The burner under the coffee pot will light automatically at a pre-determined hour A strongly built combination wagon which is equal to any emergency in which a wagon, Here we have three of the most important uses illustrated An Electric Wire in the Street Ignites a Balloon PECULIAR accident occurred re- cently when six students training for aviation work attempted toland a balloon in East St. Louis. The gas-bag came into contact with a high tension wire and im- mediately burst into flames. Luckily the basket was brushing the ground at the time. All the students were able to leap out of the basket unharmed. Prompt action in put- ting in a fire alarm brought fire fighters in time to preventthe bas- ket from being burned. The American Boy’s Wagon. It Is Equal to Any Emergency HE ordinary American boy makes strong demands on his wagon. The one shown in the illustration is equal to any emergency. It can be a common freight carrier when necessary, or a passenger car in. which lady friends may be given a ride, occasionally. But first of all it is a coaster and scooter, with a first-class steering rod and wooden wheels which never get out of order. It is close to the ground so that when it is used merely as a scooter the posi- tion with one foot on the floor-boards and the other on the ground is not uncom- fortable. bat: i 1 | eae) + ES a eee ee ee th: Ses 7 ' 7 re 1 there they must also be roasted to ‘the stifling: smell of. Popular Science Monthly This Store Sets a New Style in Exterior Decoration N the front of the only store at Point Isabel, Texas, on the Gulf Coast, a local artist has painted in their natural colors a representation of some of the fish that he has seen caught in the Gulf near by. Most of these are well-known varieties, but are some strange ones, as for example the large monster to the left of one door. This animal, of which the name is un- known, was washed ashore some 671 canoes. Volcanoes are necessarily exempt. It is possible to collect this sulphurous gas and make sulphuric acid out of it, but some plants are so located that trans- portation costs forbid. Sulphur, on the other hand, may be stored out of doors as long as desired and sold whenever there is a good price available for it. Two methods are known, a wet one and a dry one, but both depend primarily upon the French leave which sul- phur invaria- bly takes of its oxygen content in the presence of certain other bodies. years agoina storm. Getting. Sulphur Without Liberating the Fumes N regard to getting the. sulphur fumes out of smelter gas, Professor S. W. Young, of the Leland Stanford University, lately presented to the American Institute of Chem- ical Engineersa paper on pro- posed methods of procuring crude sulphur. When copper and other ores are smelted get the sulphur away from the metal. This is easy enough to do, but the fumes that escape into the air are the fumes of sul- phurous acid, and if there is anything that disposes a farmer to carry a pitchfork and a double-bar’l shotgun along with him when he goes to make his protést, it is these very sulphurous fumes in the air. In fact in some states the laws now forbid the liberation of the gases of burning sulphur in nearly every activity except that of vol- Sighd-jaica representations of different kinds of fish caught in the Gulf Stream off the coast near by decorate this store front The umbrella-holder umbrella, handle-downward, so that the water drains off into 4 pan beneath —ELLWoOoD HENDRICK.’ What to Do With That Dripping Um- brellaWhen You Come in out of the Rain N- order to properly dry out an umbrella it should be suspended by its tip so that the water will drain off toward the handle. This prevents the accumulation of water at the point where the ribs are joined, which results in rust at that point—and the pur- chase of a new umbrella. An umbrella-holder has been patented by Hermenia Bocker, of Buffalo, N. Y., which is designed to suspend the umbrella in the correct position for drying without causing unnecessary incon- venience. The tip of the umbrella is held in a clasp arranged at the top of a vertical bar. This clasp is adjustable in height so that umbrellas of dif- ferent lengths may be accommodated. A drip-pan is arranged beneath. Into this the water runs and is held until the pan is emp- tied. Rubber blocks are shoved under the umbrella handles. suspends the | 672 Popular Science Monthly How to Store Flour to Prevent It from Molding PECIALISTS in the United States Department of Agriculture have studied the best means of storing flour in the home so that it will not be con- taminated by odors or become musty. Flour should never be stored in the cellar even though a bin has been built in the cellar for that purpose. A cellar is usually damp and odors are generally found there which the flour will absorb. The attic is as bad-a place to store flour as the cellar. ; In the summer the temperaturé ofthe attic is too high and as the venti- After the envelopes are cut, folded and gummed they are passed over a conveyor to the packing boxes The electric heater which dries ‘the glue when the weather is damp Using an Electric Heater to Dry the Glue on Envelopes NVELOPE making today is an excep- tionally rapid process in which a single machine neatly cuts the paper stock, folds and glues the envelopes, and then carries these on a conveyor to the boxes waiting for them. In dry weather this process.goes on uninterruptedly; the glue dries in the time it takes the machine to fold the envelope In rainy weather, however, the wasted. ~~ A, manufacturer Chicago, Ill., places a simple electric heater. under the conveyors - of his machines. On very damp days.a heavy current is sent’. through. the resis- tances ‘of the heater, and the -hot air currents set up quickly. dry the glue.. The strength of the current de-' pends upon’ the dampness. case. The combination necktie presser and It is like a four-leaved book lation is usually poor the flour is likely to acquire a musty odor. Ex- cept in very small quantitiesflourshould not be stored in the pantry or kitchen be- cause the tempera- ture is too uneven and there are too many odors which the flour is likely to ac- Every house should possess a quire. small, well ventilated store room where non- odorous food should be kept. The temper- | ature in this room should be so regulated that it will not fluctuate more than a very few degrees. Always clean the flour con- tainer before putting in new stock. If flour is kept in the barrel in which it was purchased, boards should be placed under it to keep it off the floor. e One of the Newest Wrinkles for Keep- ing Your Neckties Smooth ES, they get wrinkled in a drawer, ‘or even when hung: ona cord strung from the chiffonier to the electric light. But here’s a_ solution. A Florida inven: tor now is market- ing a combined case and presser for men’s ties that is proving satisfactory. The device consists simply of several leaves, between which the ties- are placed. A locking mechanism. gives any degree of. pressing ten- sion desired. ss Popular Science Monthly 673 Fastening Motors to Ceilings Without Looping the Loop in a Rocking Chair Scaffolding or Tackle T is hard to attach motors to ceilings or overhead beams in factory rooms. Here -is a mechanism or de- is pe vice which is said to do . this with- great ease. It is a portable elevator or tiering machine, and it is employed to elevate and hold the motor in ‘position until it is fas- tened to the ceiling, thus eliminating scaffolding, tackle and hoisting ar- rangements. Four to six motors can be in- stalled in the time for- merly required for the mounting of one. Of course the machine can also be used for inspect- ing the motors, for tak- ing them down to be re- paired, for renewing pulleys, and for putting up shafting. The machine itself consists essentially of an elevating platform with two uprights or guides and a revolving base with a ball-bearing centeronwhichit swings like a turntable. The whole unit is mounted on a wheeled truck equipped with a floor lock. It was primarily designed for the piling or tiering of bales, cases, barrels, etc., in storerooms and warehouses, thus enabling the entire space up to the ceiling to be utilized. Two sets of elevating gears are provided. The Portable Elevator or Tiering Machine The machine was primarily designed for piling bales, cases, barrels, etc., in warehouses, so that space up to the ceiling could be utilized. Two sets of elevating gears are provided, one operating at high speed and handling loads up to 800 pounds, and the other at a lower rate of speed for handling from 800 to 1,800 pounds. It will elevate loads from six to twenty feet. The frame is hinged so that the top section can be folded over to facilitate the passage of the machine through doorways tion. Before you —for Exercise and Diversion LANCE at this rocking chair. Imagine yourself resting in it, strapped in, too, around chest and loins. It seems restful enough. But why the straps? Just for safety, friend. For this chair aspires to demonstrate perpetual motion, once it gets started. As you rock, it gathers momentum until finally—hold your breath—it turns you over and over and over like a cart-wheel. The skeleton frame- work of the chair is composed of two ver- tical, parallel elliptical hoops fastened together by a number of hori- zontal tie-bars. To these tie-bars the seat and back of the chair are attached, and also the straps which hold you while you are cart- wheeling. A bar at about shoulder-height acts as a hand-grasp. You seat yourself in the chair, strap your- self in, grasp the hand- bar and give yourself a swing in the usual man- ner. You start off gently enough, but your progress depends upon your own physical exer- become seasick, it is best to reverse the direction of the motion and thus bring the chair to its normal posi- tion, letting it gradually subside. You sit in this chair, strap yourself in, grasp the handle-bar and start rocking, turning cart-wheels, if you like and as long as you like. To bring the-chair to a stop you reverse the motion One way to reduce the cost of coal is to reduce the cost of delivery. This may be effected by motor-trucks equip- ped with quick-un- loading bodies like the one at left. It can discharge a 5- ton load in less than 5 minutes a PATA AANA wa" | \ Steam vaporizer attachment for cylinders to in- crease power Steam vaporizer Unit tire chains attached toa wheel by a bracket or strip of metal fastened to the rim with projecting hooked-over ends to receive the rings on the ends of the chains A power-driven valve seat grinder attached to a bench with special holding devices for Ford engines A new use for the old-fashioned Here the automobile is drawing an entire kitchen, side-saddle. It takes the place although on a diminutive scale. It carries hot coffee of the rear seat on a motorcycle and soup to the fighters and travels night and day 674 the Up-to-the-Minute Motor-Vehicles The auto-horse—a one-wheel tractor which takes the place of a horse for pulling unusual loads. Putting in a short tongue is the only change necessary in the wagon This tire rim is hinged at four points so that it can be packed in the tool box or easily slipped in the tire A piece of metal curved like a tile shovel is gradually slipped under the tire of a mired wheel to lift it out A new type of coil spring in horizontal position A narrow strip of cement walk is ap- under the automobile frame takes up shocks preciated when the ground is muddy 675 “Versatility” Is the Watchword Among the hdddddddddddddddédétdtéde aT WL LOLUMLLLLLLUCOLOLLOMLMA ST ccccccccccvcecc i. WDlddd A truck, with one rear wheel jacked up and belted to a centrifugal pump, rnished enough ce to pump out - Below: A freak car a flooded basement body designed on the lines of a very speedy motor-boat — e A lock that releases the steering wheel so that the wheel spins like a top Ys LTTE TTT. mmm UL ccZL.cccccozuzuz MME is cc Z An auxiliary cooling sys- tem placed in the false door of a Ford car. It takes care of steam gen- erated by the radiator x r 4 : # eS At left: A canteen that fits on the running board of the car is useful for cross-country trips Manufacturers and Owners of Automobiles 172949 *--. At left: In this Above: A nickel- new type of body, the rear seat is re- moved te obtain ac- cess to a storage compartment con- in-the-slot machine for vending air to automobiles. The hose is reeled up and locked . when cealed behind it it is not in use Cll lai Le woe eo eee e—*s SSS SAA SSSSSASU SISSIES 7 a Tw q LTTE) OT TTTLZEZZEZZZZZ:==00°/) One wheel. peeping through reveals the fact that this is an automobile in carnival dress TRON Above: A humane device for turning headlights easily to one side or down- ward so as to avoid blinding pedestrians At right: The tele- graph poles seem to be taking a ride. So they are, but it is the result of an ac- cident which snap- ped them off short 677 678 To dake the picture the camera is held tight against the finger print’ and a lever is pressed A Special Finger-Print Camera for the Modern Sherlock Holmes OR police officers and others who have need of getting finger-print evidence from material that cannot be preserved or removed from its environment, a special camera has been perfected. It. takes a photograph of the finger print wherever it may be. In operating the camera no photographic skill or experience, nor even a tripod is necessary. The camera is held tight against the surface of the door, ceiling, wall paper, or wherever the finger print has been made. The shutter release lever is then pressed down; this automatically o : closes ‘the eirenit: to: ice js the four lamps inside the camera and thus. lights them, provid- ing the illumination 4% for the exposure. +.’ The necessary cur- ~° rent is provided by storage batteries in- side the camera. Seite Popular Seience M onthly rope Details of the combination ink-bottle holder, ink-feeder and stopper, for the artist’s use Rivers That Flow in Two Different Directions HILE making meas- urements of river flow in the upper Mississippi River ba- sins and in the Hud- son Bay recently, the United States Geo- logical Survey dis- covered that some of the rivers under investigation empty into the Arctic Ocean during certain seasons and into the Atlantic Ocean at other times. Efficiency as Applied to an Ink-Bottle Holder HE accommodating bottle holder shown in the accompanying illus- tration is designed principally for the convenience of the pen-and-ink artist. The device does a great deal more than simply to provide a stand for the inkwell. It has a top section as well as a base, and this top section contains two disks to cover the bottles used, thus doing away with cork bottle- stoppers. Each of these disks is pro- vided with a quill which dips down into the bottle when pressure is exerted on the finger-piece of an attached arm which is led from the outer surface of each disk to the base of the stand. Additional pressure causes the quill to rise out of the bottle, bringing with it a drop of ink which it feeds to the point of the pen held to receive it. In this way the evaporation of the ink is prevented. _Different colors of ink may be kept in the separate bottles. A small basin is provided at one side of the wells to hold a supply of water, and cleaning cloths for the pen points. Complicated as the con- trivance seems to be, it requires only a slight pressure of the finger Pes on one of the arms to raise the top and elevate the drop of rae ink for the pen. The ‘y economy of time and of ‘ ink is apparent, since there is no clogging of the ink from dust, no evaporation, and no cork stopper to be removed each time the bottle is used. Ae - te ~ Popular Science Monthly 679 Fuel From Waste Paper—A War- Time Economy GROUP of Long Island women have devised a means of cutting down their coal bills by using waste paper for fuel. The waste paper—old newspapers, wrapping paper, and card-board which may accumulate about a house is torn into small pieces and put into a watertight receptacle. Boiling water is poured over it and it is set aside until the mass becomes soft. If it is put to soak in the evening it will be ready to handle the following morning. The mass is then formed into balls about four inches in diameter. The balls may be dried in the sun or in the oven. As soon as they are thoroughly dry they are ready to use. _ These paper briquets are said to be a very satis- factory substitute for coal. At any rate, they are capable of augmenting the regular coal supply to an appreciable extent. They catch quickly and burn more slowly than might be expected. A Fountain Ink-Eradicator. It Works Like a Pen VERYBODY carries a fountain pen. Why not fountain ink-eradicator also? That is the underlying idea of an invention patented by Robert G. Mason, of Brooklyn, New York. Two thin tubes holding eradicating solutions, fit in the rubber holder. To make an erasure, the cap on the lower end of the holder must be removed. Then the feeding valves in both tubes are released allowing drops of the solutions (chloride of lime and citric acid, each in its own tube) to moisten the spot and wipe out the ink. a2 Sa Cork : : | 4 Non-corroding » 4 Spring Liquid- container The two tubes for the ink-eradicating solutions fit into the thin holder which is about the size of a fountain-pen case When the solder is melted, the lifter is inserted in the puncture in the cap of the can, and ring and cap are lifted off together. At left is the hot ring for melting the solder A New Can-Opener Which Does Not Destroy the Can HE high cost of cans for preserving fruits and vegetables can be materially reduced by the use of a simple device which unseals the cans so that they can be used again and again. You first melt the solder around the cap on the can with the heated ring as shown in the small circular photograph above. Before applying the hot ring, you must puncture the cap; for, unless a hole is made in the cap, the atmospheric pres- sure of fifteen pounds to the square inch would hold the cap to the can as if by suc- tion. When the solder is melted, the pick, or lifter, (shown held in the right hand above) is inserted in the puncture made in the cap, and the ring and cap are lifted off together. The cans should be scalded and well washed with soda. at =% * : , Fighting at Night with Searchlight ‘Torpedoes The torpedoes carry searchlights which are lighted by means of a time fuse when the enemy ships are almost reached One by one the torpedoes are launched. They curve and glide about, revealing the enemy’s position but not that of the home fleet. F433 3 et A which could : illuminate the battleships of its enemy and be itself unseen would stand in a good way ‘to whip the best navy afloat. Torpedoes for carrying out such tactics have already been developed by Alphonse Fernandez, a Spanish inventor. Not gunpowder, but a brilliant searchlight is the charge of these torpedoes. Imagine yourself on a.fleet whose search- lights have just flashed upon several hostile craft’ in the distant darkness. Out go your lights, your stationary searchlights also, for you do not wish to give your next maneuvers away. As your ships start at once to detour, the torpedoes are made ready. These are constructed and propelled like the regulation, high-explosive Below is shown the plan of the torpedo in detail torpedo. The gyro- scopes in them are set to steer the torpedoes on a cir- cuitous path to- wards the enemy. The timing gear is also adjusted to trip the electric switch and to turn on the arc- lights after the torpedoes have gone a sufficient distance from you. Everything being now ready, the signal is given and one after another the torpedoes are launched ! They curve round and finally glide straight towards the ships of the enemy without revealing your own position. The enemy may try to dodge the beams, but before they can run out of the brilliant light of the entire school of torpedoes your gunners will have a chance at sinking, or at least, disabling their shins. 680 Popular Science Monthly {t Has Both a Pneumatic and a Solid Tire—This New Truck Wheel OZENS of inventors have patented wheels which are intended to have all. the buoyancy of the pneumatic tire and which are blowout- and puncture-proof. The problem is difficult to solve for the ordinary pleasure vehicle, but still more so for the motor- truck. As a result, nearly all motor-trucks are equipped with the solid type of tires. A new motor- truck tire has been invented in which both the solid tire and the pneumatic principleare ingen- iously combined. The drive is trans- mitted directly to the rim instead of to the hub section: | This re- lieves. the pneumatic part of the wheel from the driving strains. The wheel consists of two main parts, a hub carried on ball-bearings, with a U-shaped steel casing embracing a rub- ber air tube, and an outer part driven by the regular chain and sprocket and carrying the dual tires, as shown. The outer part has a convex-shaped cas- ing which encircles the pneumatic tube and comes into contact with it, thus providing a narrow track upon which the tire rolls when the wheel revolves. By this means the cushioning effect of the pneumatic tire is retained, with _ Driving none of its disad- aga : is openea witha vantages such as ede turtat. punctures or the bottle is blowouts. sealed and Should the leak-proof pneumatic tube become deflated for © any reason, the truck may ‘still run with- out damaging the wheel because two Dual! truck tires The drive is transmitted directly to the rim instead of to the hub section. . This- relieves the pneumatic part of the wheel from the heavy driving strain The slightest movement of 681 ing come into contact with the wide upper edges of the casing that hold the tube. The side thrust of the wheel when in motion is taken up by means of small thrust bearings between the inner and outer wheel parts as shown. Why Do Salmon Go Annually Out to Sea? HE rocks of the earth are having their - sodium con- tents washed out continually, there- fore the rivers of today. have less salt than the streams of former years. This is the reason ad- vanced for the regu- lar trips which schools of salmon make every year to the deep sea. The river having become too fresh for it, the salmon must needs go out to the ocean for the saltness necessary for its best develop- ment and comfort. Salmon are content in the rivers all the sum- Ball bearing to take side thrust mer and fall, during which time they spawn. The young make their first trip to the sea when they are about one year old. You Can’t Spill Ink When Pouring From This Bottle NM ink bottle which works somewhat on the principle of the non-refillable bottle, and which prevents waste and smearing of the hands, has been invented by Frank H. Silverthorne, of New York city. There is a small ball in the neck portion of the bottle so that the flowing ink can be cut. off in an instant. Asa further precaution a seal is provided in- stead of acork. With the seal in position the bottle will stand rings of rubber on each end of the contact cas- the hand will cause the ball to cut off the flow of the ink any amount of shak- ing without leaking. What’s Wrong with the Submarine? A submarine boat is not perfect. Two sets of motors are needed—one to drive it on the surface and the other under water. Why not use one set only? By Frank Shuman (A submarine boat must be driven under water by storage batteries for reasons given in this article. As a result, even the larger submarines are literally packed with machinery. Some of this could be dispensed with if one set of engines could be used for surface and under-water propulsion. Moreover, the dangers attending the use of storage batteries would be avoided. Mr. Frank Shuman, a distinguished mechanical engineer, famous for his wool-degreasing ma- chinery, his sun-power plant, his corrugated glass, his method of making concrete piles, has in- vented a very ingenious method of obtaining this desired end by utilizing liquid oxygen.—Editor.) T seems very wonderful that, after centuries of effort, men have succeeded in building boats which can dive be- neath the surface of the water and come up again almost as readily as dolphins. Indeed, it is so wonderful that those who have only a general conception of the con- struction and operation of the submarine are apt to believe that the millenium in naval architecture has come. The truth is that for all its deadliness, the submarine is a very crude piece of machinery. The submarine serves the very useful purpose of Conning tower Aydvoplane- | , Escape ha tches — Officers “ieee Torpedoes : taking the conceit out of mechanical en- gineers; it reveals to them how very much they have to learn about the generation of energy. Every submarine in the world is driven on the surface by what are known as in- ternal combustion engines—engines which, in a general way, are similar to those by means of which automobiles are propelled. Such an engine is curiously human. It breathes air, just as you and I must breathe if we would live. A certain amount of air must be mixed with the liquid fuel of the Electric steering Ventilators | : Grews. Anchor How Liquefied Oxygen Is Turned into Gas under High Pressure to Generate Power Power generated from liquefied oxygen is utilized. to operate first an expansion engine and then the regular explosion engine of the submarine. . Liquid oxygen is intensely cold—so cold that it boils when exposed to the much hotter atmosphere. On shipboard it is kept in a ‘container. which prevents it from boiling away as much as possible. “To convert it into a gas under Pressure, it is pumped from the container through three successive coils before it reaches the expansion engine. In the first coil the liquefied oxygen is turned into gaseous oxygen under high pressure; the necessary heat is supplied by ordinary sea water running around the coil. In other words, heat is absorbed from the sea water, which heat furnishes the main power to drive the expansion engine. The gaseous oxygen next superheated by passing through the second coil, the superheating being produced by using the cooling water which has been used to jacket the explosion engine of the submarine, around the coil. The now gaseous oxygen is still further superheated as it passes 682 Popular Science Monthly engine in order to produce that explosively rapid combustion which makes the piston move up and down in its cylinder. And so mechanism is provided which enables the engine to inhale a measured quantity of air to be mixed with a measured quantity of fuel. Now the air within a submarine is limited in quantity. When the ship is sub- merged, the crew must breathe as well as the engines. Moreover, there is the problem of disposing of the gases exhausted by the engine. They cannot be ejected into the sea carelessly. They would rise to the surface of the water in the form of bubbles and would inevitably betray the course taken by the submarine. Moreover, en- -gines are very hot, and the living quarters in a submarine are at best none too com- fortable. Because the air supply within a sub- marine is so limited and because of the very nature of the propelling engines, in- ventors of submarines have had to resort to the very awkward expedient of driving their craft under water by means of storage batteries. The batteries are heavy, cum- bersome, and not always safe; they must . eriscopes [Operating compartment - ; | Escap hatch | sinas! cham oy _ Expansion engine Oxygen ~ Carbureter Formerly storage batteries Self-bailing superstructure 683 be recharged at the surface—a noisy busi- ness which takes from six to eight hours and which imperils the safety of the craft for the time being. It is said that the newest German submarines can travel un- der water for nearly a hundred hours. That must mean a very sparing use of the’ stored power. According to Lieutenant Hinkamp of our Navy, ‘‘the submarine of the present day can operate submerged at its maximum speed for about an hour. At about one-third of this maximum speed, she can operate practically twenty-four hours.” Is it not evident, as I maintain, that the submarine, mechanically speaking, is a very crude contrivance, something of which mechanical engineers’ should be ashamed rather than proud? Needless to say the inconvenience and danger resulting from the necessity of using storage batteries for sub-surface propulsion have long been recognized. Inventors have made many efforts to do away with the storage battery entirely and to devise a way of using the regular internal combus- tion engines of the craft for under-water as well as for surface propulsion. Here, I wish to add my own contribution to the solution of the problem. It is very evident that if the engines are to be used for under-water propulsion a large supply of air must be stored in Explosion engine Steering rudder feedpump cooling water Propellers

MOR a by mp oA ‘ Construction of the new Self-clean- calibrations are made annually by the United States Geological Sur- vey, the United States Reclamation Service and other branches of radiating pipes the Government, The Largest Direct-Current Power Plant Each generator is in four parts and each of the four parts required an entire freight car in transportation The generators are driven by four- teen 6000-horse- power and one 4000- horsepower recipro- cating engines of the gas-steam type and one 1500-horse- power straight steam engine At left: A closer view of the genera- tor. Each generator - develops enough electrical energy to light 7500 arc lamps or run three hun- dred street cars. It is equivalent to 59000 horsepower ( HE installation of the largest direct- current generators ever built in this or any other country is now rapidly nearing completion at the Detroit works of the Ford Motor Company. This power plant has a maximum rating of 65,000 kilo- watts or approximately 87,000 horsepower and is the largest strictly direct-current system in existence. This immense amount of power is used to run the motors which operate the more than eight thousand machines distributed over the forty-seven and one-half acres of floor space in the Ford factory. these generators supply current for the motors of the ventilating system and the lighting circuits of the plant. In addition, © The switchboard which controls this electrical system is 424 feet long and con- sists of 222 dark Tennessee marble panels. It was built at a cost of $400,000 or nearly $1,000 per running foot. The amount of copper used in its construction for bus-bars, switches, etc., was approximately 165 tons and at current prices would be worth nearly $100,000 in the raw state. In order to give unity to the whole system and insure continuous service at all times, an elaborate signaling system has been installed. This consists of a 200-pair tele- phone switchboard which connects with engine-operating stands, boiler rooms and every distribution center throughout the factory. In the office, in connection with, 868 Popular Science Monthly this switchboard, is a panel carrying 300 signal lamps and a, duplicate set of tele- phone terminals. When a feeder is in operation a green lamp shows. This is re- placed by a red lamp when the feeder is not in operation. This makes the location of . any trouble in the rin: an easy mat- ~The field / Wee < these gigantic genera- tors is twenty-one feet high and twenty- six feet across the supporting legs. The weight of each com- plete generator is 105 tons. Five tons of copper are used in its ccnstruction. Owing to their immense size, it; was ‘necessary to construct these gener- ators in parts, for the height of the arma- ture alone is greater than the clearance on most railroads at bridges and tunnels. To transport the parts of each generator from Ampere, N. J., to Detroit, Mich., required four freight cars. Each generator develops 3,750 kilowatts at an electrical pressure of 250 volts and 80 revolutions per minute. This quantity of electrical energy would light 150,000 25- watt lamps, or 7,500 arc lamps. It is equivalent to 5,000 horsepower and the out- put of a single generator would be sufficient to run 300 street cars. Each gener- ator supplies continuously 15,000 amperes of current. The whole plant supplies 260,000 amperes. The total output is one-eighti- eth of the potential ca- pacity of Niagara. These generators are driven by fourteen 6000-horsepower and one 4000-horsepower reciprocating engines of the gas-steam type and one 1500 horse- power straight steam engine, all of which are direct-connected to the shafts of the genera- tors. The water used erator by a Here you get an idea of the size of the gen- simple comparison of the field casting with a four-passenger Ford car Germany’s spike-studded boards which were left all along the roads when the Hindenburg Line retreated. They were intended to cripple the pursuing Allies but they were discovered in time 869 in cooling cylinders, pistons, valve boxes and bearings of. the gas unit leaves the engine at a temperature of 175 degrees Fahrenheit and is utilized for boiler feed and hot water factory supply. The exhaust gases, at a tempera- ture of 1100 degrees Fahrenheit are em-, _ ployed to maintain the temperature of the steam between the high and low pressure cylinders of the steam engines, after which it pre- heats the boiler feed water. The steam ‘engines are of the double expansion Corliss type. © The boilers contain 1800 tubes having an ap- proximate heating surface of 26,000 square feet. One of the Ways the Retreating Ger- man Army Tried to Prevent Pursuit HEN the Germans made what has be- come known as the strategic retreat of the Hindenburg Line they very naturally wanted to prevent the Allies from following them too closely. Various obstacles were put in the path of the pursuers. Those which they counted on to make the most trouble for their enemies were huge spiked boards, shown in the accom- panying illustration. These wicked-look- ing boards were placed all along the roads and in the trenches. They are constructed of heavy planks thickly studded with spikes. These were covered over with brush, leaves, branches of trees or any other available “‘camouflaging’’ device which might be de- pended upon to con- ceal the obstruction from the rapidly ad- vancing troops. Efficiency Hints and Little Helps for Your Office, Sir Above: A standard with separable trays for sorting and filing mail Gummed washers as tie fasteners to be attached Mucilage to an envelope or package Spreader containing other than first class mail matter Adhesive tape container with moistener for binding packages Below: A pin tumbler lock for loose leaf binders 4 NOn-corrod ig spring With this container mucilage may be applied and spread without getting the fingers sticky A stamp pad with an ink- ing ribbon roll similar to a typewriter ribbon A card-index holder having the names and addresses of customers in plain sight and the nota- A printing attach- ment for paper roll holders.. It prints advertisement on tion covered over each strip of the by the _ overlap- paper torn off to ping index sheet Blue print file and desk with drawing- wrap a package board attachment for copying notes and measurements coveniently 870 Do It With Tools and Machinery With an _ oxy-acetylene blow-pipe . five . hundred stay bolts were cut in fifty-eight minutes, a record time for such work RANE Testing cartridg plug-gage heads to close limits, by the use of a fluid gage This holder for chisels and plane irons keeps the edge at the proper angle A tap or spout for puncturing a can cover. When at- A holder to be attached WS WES AA) to a screw- driver sothat Zs icc N /))/ a nee tached to the can a screw may by a thumb nut, it be held delivers the con- and turned tents in driblets nid dldld hile tile Villllliiihlisiben A paint gun for applying liquid coatings. It works on the principle of an air brush | | i | = : ay a é pore are seat es — LOE OO. An instrument that shows the elasticity Wheelbarrow that folds completely up of a bar. Method of placing it on the bar so that it occupies little storage space 871 An Engine-Carrying Fin. for the Power-Baa A device for conserving floor space on the boat and for enabling the boat to turn in its own length PPC cere ror pememenmecessasene ms Ws TED eae “ ‘ ae % The engine-containing fin principle applied to car floats. These large, clumsy floats can be — handled as easily as a light motor-boat, and the need of a tug is thus done away with LL the captains who sail the briny deep are not satisfied with their ships. Captain Samuel Golden was not so pleased with ships as he found them that he did not think they could be im- proved. Therefore, he thought out meth- ods of improving power-boats. So far the captain has built three boats, all designed along the same lines. The last one, known as the ‘‘Shib 11”’ isa forty-foot houseboat equipped with a four- cylinder 28-hp. engine which operates at about 500 revolutions a minute. The peculiarity of the construction lies in the fact that the boat is equip- ped with a fin which is about twenty feet in length, twenty- seven inches in width at its wid- est part and twenty-six inches deep. The engine is built in this fin. The propeller is an ordinary three- bladed side pro- peller, twenty- two by. thirty- inch pitch. The rudder is smaller than those used in other boats of her size. . contains the engine. The entire fin water. A new type of boat which has a short narrow fin that The propeller is always under This boat may be steered with great precision 872 is submerged. The water flows around the extreme lines of the fin without any suction. Therefore, the full surface propeller blades are available for pulling as well as thrusting. The thrust from the propeller cannot rise into the air. No air can reach the wheel. The short narrow fin and the position of the rudder and propeller make it possible to steer the boat with great accuracy. One advantage in this construction lies in the fact that this type of boat may be used for many purposes, such as for tugs, lighters, pleasure boats, speed boats, ferry boats and power life-saving bo-ats&-77fea crowded harbors it is very neces- sary to be able to handle ships without~- mishap. ° The invention of Captain Golden makes it possible to turn any Ves- sel in its own length and makes steering far more accurate than it is with ordinary boats. The size of the fin is in propor- tion to the size of the boat. Inthe case of a float for railroad cars the | finislargeenough to bea good-sized engine room. Popular Science Monthly 873 A power-boat equipped with a short fin. The position and construction of the fin make it possible to turn this boat around in its own length. This is an important feature in a crowded harbor two-hundred-and-fifty-foot float would have a fin twelve feet in width. The engine would take up four feet, which would leave four feet on each side for passageway. On -such a large boat a great part of the engine would be above the fin and there would be plenty of room to get at any part of the mechanism. Small boats, like motor-boats, have a narrow fin and a correspondingly small engine. All that is necessary in such boats, _ isarmspace around theengine. Amancan reach any part of the engine from the floor above it. Zip! Zip! The Electric Fish Scaler Is Cleaning the Fish NEW device which has re- cently been patented by Louis Weinberg, of Chicago, will enableanybody to scale a fish in the shortest possible time and with very little effort. Thisinvention looks like an old-fashioned music-box cylinder, except that the teeth are mounted on a tapered body. The scraper blades or teeth are larger and farther apart on the thick part of the body and finer and nearer together where it tapers. The coarse blades ‘are to be used on large fishes having heavy scales. electrically. Turn on the current and scale your fish A flexible shaft runs from an electric motor to the tapering scraper Can a Fish Frozen in the Ice Be Restored to Life? CCASIONALLY a “fish” story gets into circulation which has such a scientific flavor that it challenges the credu- lity of even the very well informed. To this class belongs the story of the resurrec- tion of a fish called the ‘“Chindagaks,” which, it is reported, will come to life again after having lain frozen solid in the ice for months. According to the authorities connected with the United States Fish Commission, the Chindagaks is a newcomer not only into the field of fish literature but also into the lists of known species. None of the experts on the Commission has heard of it before. They declare that when a fish is entirely frozen, life is extinct; though it is possible for a fish to appear to be frozen when its flesh isonly stiffened from the cold. The blood is still uncongealed, therefore the fish is still alive and will, of course, revive gradually when placed in water of the proper temperature. Even this will happen only to a fish which has been caught through a hole in the ice and left lying exposed on the ice surface until it has become stif- fened from the cold. ) Motor ——SSS= —— 874 Popular Science Monthly © int. Fiim Serv. : This building was constructed entirely of corn. The color effects were obtained by using white, purple, yellow and red corn, many thousands of bushels being consumed in the making Residents of This Western Town Are A New Christmas-Tree Stand That Not Worrying Over Corn Shortage Prevents the Tree from Tipping — ene over the bumper crops which NEW type of Christmas-tree stand is have surpassed all previous records, the like a giant bottle with a broad base, residents of Mitchell, South Dakota, have _ into the neck of which the tree fits snugly. given vent to their enthusiasm by building The bottle, or shell of the stand, is made of ‘an enormous palace in which all the sheet metal or galvanized iron, and is intricate designs in the ornamentation, to be filled with sand before the tree is as well as the entire framework, are inserted in the neck. “This gives con- worked out either in grains of corn, siderable weight to the stand and cobs or stalks. The points of holds the tree steady. stars in the American flag de- When the tree is taken down, it is signs are ingeniously formed only necessary to turn the stand up- from quarter-sections of sharp- side down in order to empty it of the pointed ears of corn. inlet sand. Water may be used Thousands of bush- water used instead of sand, if desired. els of corn were con- F weight The use of water will sumed in making the make the _ stand palace. We are won- equally weighty and dering if the enthusi- will serve to keep the ‘astic corn-growers have tree fresh’ and‘ gréen heard the food conser- Corik much longer. It is so vation appeal recently This bottle-shaped Christmas-tree stand simple that .a child made to the nation. may be weighted with either sand or water can adjust it. Christmas tree trunk Popular Science Monthly House Numbers in Concrete—You Can See Them from Your Car HE latest style in house numbers in Pasadena, California, utilizes concrete blocks in which the numbers are molded. These are set out on the edge of the curb so that he who runs (in an auto- -mobile) may read without getting out of his car and walking up to the house to find out whether Jit is the place he is looking for or not. _ The blocks are only four by seven inches, face surface, with tri- angular sides, that slope back from the street. The ruler shown in the picture is placed so as to give an idea of the size of the lettering. Concrete Setting Broken Bones by a Portable Machine ~~ Pegs machine for setting fractures ot the legs has been designed and pat- ented by John H. Wilting of Buffalo, N. Y. One of the most interesting features of the apparatus is its light weight, thirty-five pounds. The average fracture-setting ap- paratus is too heavy to be moved about blocks bearing the house numbers are set on the curb in front of the residences 875 from place to place. This one may be car- ried by the physician to the patient. When the machine is unpacked the case acts as a rest for the body of the patient. Two arms support the legs. These arms are so arranged that the injured member may be set so it will be exactly the same length as the uninjured leg. The measure of the un- injured leg is taken and the injured leg is drawn out to correspond to it. Movable supports are provided for the limbs. Hence there is no strain on the fractured leg. The supports are made of wood fiber so that X-ray pictures may be taken of the leg while it is rest- ing on the supports.+ A plaster cast may be put on the fractured leg while the patient is on the machine. When the machine is packed up it fits compactly in the case. This apparatus should be very useful for army purposes because it is so easy to move it about. The case is the size of an ordinary suitcase, and is made of black walnut, with a dust-proof cover. The large amount of aluminum and fiber which enters into the construction of the apparatus explains its extreme lightness. A fracture-setting device which may be operated anywhere. The entire apparatus may be packed up in the case on which the patient’s shoulders are resting, and it weighs only thirty-five pounds A New Sea Camouflage Foils the Submarine A painted curtain is used to conceal the guns and make the vessel appear unarmed The U-boat approached to within twenty yards of her intended victim believing her to be unarmed. Then the false curtain was dropped from the after-poop deck, revealing the big stern gun. ‘The submarine was destroyed by the gun’s first shot, the whole crew perishing T least one German submarine has_ already been sunk by the latest adap- tation of camouflage to sea warfare in the form of a painted curtain to hide the stern gun ofa merchantman. The purpose of this new adaptation of the camouflage idea which is now so commonly employed in connection with armored cars and tanks is to get the submarine to approach the vessel under the impression that she is unarmed and then to put the gun into play so quickly that the U-boat cannot submerge in time to escape being hit. While this kind of deception has been practiced in different forms, such as the dummy funnels and fake topsides of the German raiders Emden and Moewe and in the many grotesque futurist daubs of paint with which some of our own vessels are now blessed, this is the first time the ruse has been employed for the benefit of the sub marine. ) According to the officer of the British vessel which had the encounter referred to, the German submarine was first seen some distance away with her periscope showing. The ship’s big gun was hidden behind a collapsible curtain screen which covered the 876 entire stern and which had been painted to resemble lifeboats. The curtain was in sections, each with rings slipped over extensions of the rail It was lowered instantaneously uprights. as a unit by means of ropes running over small pulleys at the top of each upright and tied to a cleat on the deck. The subma- rine approached to within twenty yards of the vessel. Several men clambered up out of the forward hatch with a collapsible life- boat... The ship’s cur- tain was suddenly dropped; the guns were brought to bear, and fired. The first shot struck the U-boat at the base of the peri- scope and she sank in four minutes carrying her crew with her. - The Up-to-Date Baby Has a Wheeled Dressing Table CERTAIN Philadelphia (Pa.) manu- facturer is putting out on the market a baby-dresser on wheels, - whichis nothing more nor less than a stout piece of fabric stretched on a frame and supported on wheels, so that it can be moved from one room to another. It is large enough to hold the baby’s toilet articles as well as the baby himself. The frame is made of steel with rubber tired wheels. It is rigidly locked when in use, but easily folded up and put out of the way when not in use. It occupies a very small space when stored. It is perfectly balanced and cannot be tilted over, nor will it close up before it is locked. When not in use for baby, it can be used as a tea-serving table. Popular Science Monthly Painted life boats in front of dummy deck house Quick-action pele ropes to make Curtain drop instantaneously as one unit. The top picture shows the camouflage curtain in position, its painted lifeboats plainly visible from a distance. The lower picture shows the curtain lowered and the gun deck cleared for action This is much better than the nurse’s lap after his bath, thinks the baby 877 Butter? No; Pass the Oleomar- garine, If You Please N some parts of Germany, according to the Bulletin of the Chicago Section of the American Chemical So- ciety, oleomargarine i is quoted at higher prices than butter. ‘Now how do you account for that ?’’ asked a man as he read it. We have ‘no direct information so we claim the privi- lege of several guesses. The statement does not record just what kind of butter it is that is cheaper than oleomar- garine. Some of us can hark back to stu- dent days in Germany and recall little plat- ters of virile, puissant and mighty butter that were placed before the guests at the table (but not the landlady), and the memory of it, through the long and arduous years, carries the sense of economy. Butter like that seems bound to be cheap; by rights it should be cheap; cheaper than anything else one can think of. But there is another reason which may explain why even good butter may be worth less than oleomargarine. There is a fat famine in the land, and oleomargarine pro- duces a greater number of calories than butter. We are told by those who have traveled in Germany since the war has been raging that the craving for fats, after being on short ‘rations for a while, becomes so intense that the mere sight of butter induces a disposition to throw all propriety to the winds and devour the fat like a beast. Oleomargarine may ‘‘go further’ than butter in satisfying this intense craving.— ELLWoop HENDRICK. 878 Popular Science Monthly A Motion Picture Camera | That Stands on One Leg RTHUR SELDEN of Roch- ester, N. Y., intends to employ a-single- swinging: sup- port in place of the stationary tripod of a motion picture cam- era to facilitate the following of moving objects and a crank at-. tached to the operator’s belt to minimize vibration by indirect driving. No provision is made for focusing. —~ In motion picture works lenses of universal focus are not em- ployed. An object moving to or from the lens within certain distances will necessitate re- focusing. At the same time the crank must be kept in mo- tion without the slightest varia- tion in speed. The photog- An exact reproduction, in miniature, of a large hotel now being built in New York. The windows are of real glass A Miniature Hotel With Two Thousand Rooms HE picture above shows a remark- able model of a gigantic hotel which is planned for New York City. The model is a faithful representation of the building as it will appear. Every little detail of ornamentation, coloring, light- ing effects and general construc- tion has been faithfully por- trayed. The result is a little palace that might accommodate a whole community of Peter Pans. The model was con- structed from the plans of the architect who designed the great hotel that is to be. The ma- terial used was wood pulp stained to imitate perfectly the stone which will be used for the new building. The windows of the miniature are of glass. The real hotel when finished will be enormous. It will have a ballroom which will ac- commodate three thousand dancers. There will be two thousand guest rooms in the building and preparations -——=————— LN to belt rapher using a camera with a single swinging support would find both his hands well em- ployed. Focusing of: the lens when the necessity arose would be impossible. It is doubtful, too, whether a smooth, even turn could be made with a crank attached to the flexible body of a man. - Although in this case the inventor has given most of his atten- Re tion to a more accurate centering of an object in motion, it should be re- membéred: that this fea- ture, with rare exception, is not desirable in motion picture work. An ob- ject in motion which is continually photographed in or near the center of the film in spite of its movements will, when projected on the screen, dazzle the eyes of specta- tors, because the back-. grourid, which is greater in area, will assume in an opposite direction the identical motion which. has been arrested in the object. At best, ' the majority of such pictures are some- Flexible shaft) Crank attached are being madeto serve more than a million people during the first year it is open. The << Oris using acamera with a single swinging support, such as the one shown, would find both his hands well employed what confusing and consequently seldom used, Popular Science Monthly Commuting by Airplane from the Suburbs to New York r. April, 1916, the New York Flying Yacht Club, the only club of its kind in the coun- try today, wasorganized for the pur- pose of estab- lishing on the Hudson River a sta- tion where aviators and 879 ing their machines. On the roof of the structure will be two observation cupolas. which will be used chiefly by officials for timing the races. The roof will also have a aya searchlight that will be a guide to the aviators who fly in the night. The searchlight will casta bright per- pendicular beam heaven- ward contin- ually every owners of hy- nightand this droplanes will be a bea- could “house” contothemen their ma- coming home chines after to roost. making fly- A string of ing trips to The proposed club house of the New York Flying Yacht Club hangars will Manhattan and its string of hangars in which the hydroplanes will rest be built on Island. The ' the water’s day is coming when ‘‘commuting”’ be G air- edge close to the club house. These will be craft will be a common thing. It has been done already by a few wealthy men whose homes are on the water front several miles from New York city. These air travelers will find it necessary to have “‘garages’’ for their machines while they sojourn in the city. The hangars will be erected near the club house which will soon be erected at One hundred and Twenty-ninth Street and Riverside Drive on the Hudson. The club building will be two stories in height, with a spacious roof garden. A cater- ing room and a ban- quet hall will be found on the lower floor. The trophy and club rooms will occupy the second floor. A balcony will _ surround each floorand the structure will have verandas on all sides where members and _ visitors can sit and watch the machines in their flight over the land and river. A gangway will lead from the south side of the structure to the . river, and this walk will be used by all per- sons leaving and board- so constructed that an aviator can pull in or take out his flying machine with the greatest ease. The hangars will be big enough to hold the very largest’ types of hydroplanes, Using the Heat from the Hot-Air Furnace for Cooking Purposes F you have a hot-air furnace you can do your baking by its heat. Here is how it may be done. A sheet-iron oven can be built into the hot-air conduit, as shown in the illustration, and the > ae if 7 heated air can be made ) to flow around the Damper sides and the back of en ) the oven. By this heat openings y the contents of the Shelf Hollow wall Heat to : atmosphere —=. Wall register—~ ff Pipe from furnace 7 Heat from furnace ~-~__4 The hot air rising from the furnace heats the oven and circulates around the contents oven will be thoroughly baked and none of the disagreeable gases in the hot air will be allowed to touch them. Apparently, here is a‘ practical device which’ can save many a dol-' lar on your coal and gas bills. That at least is what Albert Caro, of Illinois, who is the originator of the idea and inventor of the oven, believes. An ‘Imported Jungle in a School Yard | A method de luxe by means of which one set of children could dispense with school books HE children in the family of Mr. -George Getz, of Chicago, IIl., are not inclined to neglect their school work. In fact, there is little difference between the school hours and therecreation periods; for according to the system of education which Mr. Getz has established for them, school work 7s recrea- tion. ~ On the Getz estate at Lakewood, Michi- gan, where the chil- dren pass the greater part of the year, there is a veritable jungle, full of animals, wild and tame, from which the lessons in zoology may be illustrated at first hand. There are camels on which the youngsters may ride while they learn all there is to. know from the Arabian caretakers about the habits of the camels and listen to tales of mystery about the great African desert and’ In the aviary almost every kind of bird known to man is kept. in story form in connection with the bird’ and animal lore of the different countries in fairy stories. The schoolhouse, built for three children, answers the purpose of a church on Sundays parts of the globe. Arabian lore more interesting by far than The children know all about the honey bear, the various types of mon- keys and other small animals, including guinea pigs and rab- bits. All are to be found in their Private ZOO. When the lesson is. on birds, there are’ still finer facilities for study. In theaviary, there is almost every kind of bird known to man. These are kept in congenial groups under the care of ex- perienced fanciers. Of course there are all kinds of flowers to supply not only beauty of landscape and material for bota- ny lessons, but also nectar for the bees. There are vege- tables and farm ani- mals of every descrip- tion, some native to the United States and othaes from different Geography and History are taught at the same time and in connec- tion with the Nature study. 880 ate eee ae ee a History and Geography are taught Popular Science Monthly Illuminated Muffs—They Rob London Fog of Its Terrors LLUMINATED wearing apparel hereto- fore has been designed chiefly for men; now the women may blaze forth in glory. Take, for example, the muff illustrated here. It is adorned with an animal’s head having twoeye sockets into each of which a small electric bulb is screwed. A bat- tery nestles comfortably in a pocket in the bottom of the muff. Wires con- nect eyes to eyes, and eyes to battery. A push button is inserted in the circuit—and the muff is ready for opera- tion. If, on a dark night, our lady drops a coin, léses her way, can’t find the keyhole—she need only press the but- ton and lo! there will be plenty of light. When the fog settles down over London, ‘during these times when the streets remain unlighted at night on account of air raids, the wearer of one of these muffs will not be likely to become confused or disturbed. Above: illuminated. At right: Diagram of the wiring plan - The Homemade Ice Sleds of the Chinese Boys LJOYS are boys the world over, and they will find a way to enjoy the ice and snow, whether they know anything about skates or not. In China, skates are a great novelty, and are seen only in cities in which The muff The Chinese boys fashion their sleds out of odds and ends of wood and push them over the glassy surface with spiked poles 881 many Europeans live. But when the canals freeze over, the youngsters flock to the ice with the instinct of ducklings for water. They make a kind of sled out of odds and ends of wood—-and wood is a luxury in China—and then add to their equip- ment a long pole having a spike in one end. Standing on the sled, they push themselves along at a fair rate of speed, and their screams ‘of enjoyment are not less hearty than those of boys in other parts of the world. Generally speaking, China is a cold country compared with western territories in the same latitude. The winters are much more —~. flectric severe and of “Sa, bulbs longer dura- ch tion than ey i ours, so that the little Chinese boys get a great deal of enjoy- ment out of their impro- vised sleds. Mysterious Sounds That Continually Baffle Science YSTERY still attaches to certain ex- plosive sounds, heard in various parts of the world and known to science as “brontides.”” On the coast of Belgium these sounds seem to come from the sea, and are called locally ‘‘mistpoeffers.” In the Ganges delta, of India, similar sounds are called ‘‘Barisal guns.’’ Brontides are well known in some parts of Italy, where they bear a great variety of names. In Haiti a sound of this character is known as. the “‘gouffre,’’ while in parts of Australia it is called the ‘desert sound.’ Brontides mostly take the form of muffled detona- tions, of indefinite direction. Probably they are of subterranean origin. Studies of eccentricities in the transmission of sound through the atmosphere, lead to the con- clusion that some of the sounds hitherto reported as brontides were really due to cannonading or blasting. Making Flour from Pigskin A de-hairing machine leaves the skin so free from » dirt that the ‘“‘cracklings’’ can be used for bread By Lloyd E. Darling N Chicago a certain factory makes a business of putting out what are called « ‘hog de-hairing’’ machines. The func- tion of these devices is to clean up a hog after the slaughter—thereby supplanting an old-fashioned process which made use - of knives that scraped hogs razor-fashion. Porkers used to emerge from this latter process looking like an old-time Yankee— that is, reasonably smooth-shaven as to face, but exhibiting a sizable beard under their chins that the mechanically-wielded knives hadn’t been able to reach. For the same reason the under side of their legs was left unshaved. With the newer kind of machine, how- ever, the pigs emerge thoroughly cleaned up—so immaculate in fact that they are referred to in the pork-packing profession as “polished.’’ This is accomplished by thoroughly scalding the hogs in the usual fashion, and then running them through a machine which is nothing more nor less than a battery of “‘beaters.”” The beaters are built up of thick canvas. or rubber belting bent in the form of loops and studded with an- gular metal pieces which do the actual work of ‘‘polish- ing’ a hog. These loops are attached to steel shaft- ing which is revolved at a rapid rate by means of suit- able chains and gearing. A hog about to be polished’ is made to run the gauntlet of a: whole row of these rapidly- revolving shafts, armored as they are with their steel-studded ; loops of belting. He is spanked, : and batted, and massaged, and rolled over and over by the flying loops. They remove his whole outer skin or ‘‘scarf” at the same time that the hair de- parts. Luckily he is dead or he might seriously. object to such treatment. Some of the loops revolve up and down and the others laterally, thus causing The de-hairing machine with its battery of ‘“‘beaters” the hog in his moving around which polish up the hogs Coming direst from the scalding tub the hogs are now ready for the final polishing — to be struck from all angles so that every portion of his anatomy is reached. There is no Yankee beard effect left when these machines get through with him. His own mother wouldn’t know him, as the saying goes, he is so much changed in color and general state of cleanliness. The machines are built in a variety of forms, through some of which the hogs go vertically, through others ‘horizon- tally. The machines work with great rapidity as compared With old knife-scraping forms. Some of them have a capac- ity of one thoroughly cleaned hog per second. These hog-cleaning ‘ma- chines have been installed now in practically all of the commercial packing plants of the country. The fact that they so thoroughly clean the porkers is far-reaching in its effect, especially from the consumers’ point of view. One of the beaters; showing how they are attached to the central shafting 882 Popular Science Monthly 883 Reclaiming Discarded Metal from Scrap Piles HE price of metal has risen to such an extent that many con- cerns are searching their scrap piles in an endeavor to find parts of ma- chinery which may be repaired and put back into use. At one Western mine enough dollies and dies were found in the scrap pile to last three months. They were welded up at a cost of one dollar each. New ones would have cost.nine dollars. In the same scrap heap enough short ends of tungsten steel were found and welded together to. last a year. Drawing the hogs up out of the scalding tub, preparatory to passing them through the machine As before mentioned, pickled pigs’ feet, and snouts, and tails, are much more palatable because of the absolutely clean condition of the epidermis. The brine is not contam- inated with hair and dirt left on thevskin. Even the ears on the hog are polished inside and out. » It is through this cleanliness obtained by new packing processes that it is now possible to make desirable flour for bread from the skin of hogs. In every pork-packing plant there is a residue left from the process of trying out lard. It is a mixture of fatty tissues and _ bits of skin. It is called “cracklings” and is very similar to the residue obtained by housewives when frying out bits of grease. These cracklings from a _packing plant come inrather dry form, * the various bits havin caked together in the proc--: ess of squeezing out the grease. It is these cakes ' that the maker of pigskin flour grinds up. The re- sulting powder is very clean in appearance, and is slightly yellow in color like fine corn-meal. Mixed with a slightly larger por- tion of ordinary flour, this substance makes very rich bread, without additional ‘“shortening,’’ and is con- sidered decidedly pala- table and nutritious. | Inverted # parachute Pull the trigger of this toy gun and you shoot out—a parachute In the scrap pile of a railroadshop a lot of old locomotive drivers were found. These had been discarded because of cracked spokes. The cracks were welded and the wheels are again in use. This reclamation of scrap is made possible by the oxyacetylene process of welding and cutting. Before long, searching the scrap pile will be almost as popular, and perhaps more profitable, than digging for gold., A Toy Gun for the Pacifists. It Shoots An Umbrella NE of the latest additions to the list of harmless weapons for the juvenile warriors is a gun which shoots out from its barrel an unfolded umbrella, or para- chute and flag. A strong spring takes the place of powder. The firing mechanism is very similar to that of the ordinary small- caliber revolver. When the gun is ready to be fired the umbrella lies telescoped within the barrel. When the trigger is pulled the hammer is released from its cocked posi- tion, striking the fir- ing pin and releasing © the catch holding the umbrella. Thus re- leased the umbrella is forced out of the bar- rel and is unfolded, the ribs which hold the frame out and retain the extended para- chute in shape being attached by cords to the gun. ‘ Jerces Science Monthly A Labor-Saving Dump Car. It Does Away with Shovels OTH speed in unloading and economy of labor are se- cured with a new dump-car which throws material to either side of the track. The side of the car turns down when dump- ing and serves as an apron to carry the material clear of the track and cars. In this respect the car differs from any other made, as it discharges the ma- terial in such a position that no labor whatsoever is required for The lion was photographed on. the first exposure. Afterwards the man was taken The actor must-see the - lion -in front. of him justasplainly ~ as does the audience - “How “the Lion and the Lamb” Lie Down Together in the Motion Pictures HAT chances actors take!’ you may exclaim when you examine the photograph above, showing a man and a lion, with a none too pleasant expression, in a hollow log together, each apparently unaware of the presence of the other. It seems a pity to spoil the effect of such a good thriller by - shoveling. ‘As the regular train crew can handle the dumping apparatus, the services of section gangs, regular laborers, or extras are not required for dumping. The speed of unloading also releases the rolling stock quickly; for the cars may be immediately returned for loading, instead of being held for about: ten days as formerly. A car is dumped_ by compressed air, and one car or an entire train can be dumpéd at one time. ‘The dump car is all steel, and the body is supported on — rockers: Equilibrium is provided: for by a flat place in the center of each rocker sur- face. In dumping, the box:is merely tipped off this flat surface. When the box is empty the low center of gravity ‘causes it to roll back into place. The: car- may be dumped to either side by making“a slight adjustment. A link fastens the car in the upright position, and a separate lock makes it impossible to dump the contents to the wrong: side. On a single division of an Eastern and the cost of removing waste was reduced by the side dump cars from $100 to $37 a day. telling the truth about the filming. The lion alone was taken during one ex- posure of the film. When he had bowed himself out of the log and back into his cage the man was allowed to take the center of the screen, or rather of the log, and was photographed in proper relation to the lion on the second exposure of the same film. But on the screen, of course, they both appear in the log at the same time. The side dump car in operation. an apron to carry the waste material clear of the tracks The side piece acts as Barking Wood by Penery. The logs of wood are made to rub against each other and scrape the bark off automatically OOD barking today is not what it \ \ used to be—a hand process carried out with long sharp knives. One or two hollow steel drums are all that are now seen in the modern barking mill,— drums that remove the bark from many tree trunks at one time. Perhaps a dozen huge trees are cut up into a thousand pieces. These are fed into one end of the horizontal, rotating drums. The angle irons, which make up the steel framework, grip the edges of the logs, tumbling them about so that they rub against one another. The bottom of the drum is immersed in a tank of water, so that the bark is soaked and easily peeled off. Fresh logs fed into the drum on con- veyors push the barked logs on to dis- charge-conveyors at the opposite end of the drum. The con- struction of this barking drum is as in- genious as is its principle. Since jt . would not do to immerse the bearings. of the drum in the water, the drum is ' suspended on endless chains which run over pul- dry” on the top of the barking machine structure. There is little about the operation that requires attention. In fact, one operator now takes the place of nine skilled whittlers. Altogether, the result in a fair-sized mill which turns out six or seven hundred cords of barked wood in a day, is a saving over the hand method of about three hundred thousand dollars a year. Strangely enough, though theory would seem to indicate that sharp points mounted radially in the inside of the drum would be more efficient than blunt angle irons, such points are not the choice of experience. While these points would peel off the bark in considerably less time than the irons do, ' they would also dig into the ‘‘flesh” of the wood. The resulting saving in time would be more than offset by the decrease in the commer- cial value of the wood. For this rea- son, it has been found best not even to grind down the edges of the angle irons. As a result the wood comes out without a bruise. Diagram show- unbarked weer yeturny _ Taran ing the principle and operation of the wood-bark- ing machine. A re gee The revolving drum which makes a thousand or more 18 an logs peel off their own bark. It is operated by one man From sawor fe scrapers wood pile ) Fa) [al aaa a -~~=.\ Wood intake z : (oO) \ \ Q t ai =» A | dozen huge trees cut up into a thousand or more pieces may be fed into the drum at one time, tumbled about and end \\ ] ue soaked in water “fear Ex conveyor \ ba Barked conveyor to boiler room = Perforated plate and finally dis- charged clean 885 Protecting Battleships with Compressed Air | Should a vessel be torpedoed the inrush of water will be stopped by outrushing air under pressure into giant diving bells or caissons to help protect them from torpedo attack. It sounds impossible, but it is not; for it is merely adaptation of the principle of the air lock. This has been used for many years in sinking underwater foundations or driving tunnels under rivers. and even in ship salvage work. The hulls of the ships have simply been divided into a large number of compartments to be filled: with compressed air. Should one or more of | these compartments or chambers. be_ shattered by the explosion of a tor- pedo or mine, the ad- jacent compartments are filled with compressed air until the pressure of the air counterbalances that of the water in the dam- aged section. When this occurs, no more water can. flow into the vessel and she may be towed into > port or proceed under her own steam if her engines: have not been damaged. - Almost the same con- ditions hold true in or- dinary . household work when. an empty tumbler is plunged.bottom upward into a dish-pan of water. The water enters just so far, until the air trapped-in the glass is com- Uae SAM'S ships have been turned (©) Press Illus. Serv. The wake of the torpedo. It is the only warning which the threatened vessel usually has pressed to a point where its pressure equals - that of the water.,; Then né more will enter. As shown in the accompanying illustra- tion, the hull of the ship is divided into a great number of compartments. Should one of .these be punctured by any means, the ones next it aré' immediately filled with — - compressed air until the water pressure is equalized and no more can flow in. The compressed air may or may not come into contact with the water in the damaged compartment, according. to whether ‘one or more than one chamber is punctured. In any event the pressure of the air in the nearest surrounding intact compartments ‘acts equally in all directions and is liable to make the bulkheads and decks leak. For this reason air at a lower pressure is Sa aer pumped into the adjacent compartments, the pres- sure diminishing as the distance of the chambers from the damaged area increases. In this man- ner, the difference in the pressures in the adjoining compartments is only a few pounds and the bulk- heads and. decks are well — ‘able to withstand it with- out leaking. The use of this system has occasioned very little change in the design of the vessels, ‘for battle- ships always have been divided into many cellu- | _ lar divisions for restrain- . ing the inflow of water through damage by col-. lision. Again, means for pumping the compressed > air into the compart- ments was. already; in place.in the form of pipes to pump fresh -air: into and exhaust foul air from the chambers. Compressed air is falee a common commodity on battleships, being used to run the refrigerat- ing machines, to fire torpedoes as well as charge them and to remove the hot gases from the gun barrels after firing. It was therefore only necessary to provide suitable means for connecting the compressed ‘air supply with the compartment pipes. This did not of course change the design of the inner hull or appreciably increase its weight. The system, the invention of William Wallace Wotherspoon, a New York City -engineer, was first installed on the armored cruiser North. Carolina. All of our recent battleships have: the system, so that our sailors crossing the seas or working in the war zone have a chance against torpedoes. 886 The Air-Lock Principle Applied to the Battleship Air tocks to oerie mens to descend into dartiaged" compartment if all water . AS = ows out py the air SAir supply -Armor The broken- -away section at the left shows how the compartments in the way of the boiler-room would be filled with compressed air were the vessel hit amidships. Similarly, the section at the right shows how the compartments would be filled if the boat were hit near the bow. At the left it is noticed that the intact compartment nearest the damaged area is filled with Foiling the Torpedo with an Armor of Air compressed air at a pressure of fourteen pounds to the square inch. Adjacent compartments are filled with air at the lesser pressures of nine and four pounds, ac- — to the distance from the punctured section. A ship thus injured could proceed to port under itsown steam. The air locks permit mento descend into the injured compartment to make temporary repairs. 888 A Novel Color Mixer for Teaching Blending Effects VERY simple and novel device for illustrating the various color effects produced by mixing different paint pig- ments can be made in the follow- ing way: Prepare a series of pigment ‘“‘matches,” as shown in the illus- tration. This can be done by obtaining the soluble pigments in dif- ferent colors and making each into a thick paste by mixing with a little glue. Dip the end of a match stick into the gio seai- pigment and when the’ ment adhering mixture dries, mount it on a card- board with one or two other similarly prepared ‘‘matches.’’ When these are immersed in a cylinder of water, the pigments at once dis- solve, and as they inter- Blue dipped sa mater = Clear water—+ Green mix=+4 ure Yellow dipped match = 3 ped atpped = * natch Popular Science Monthly Shoe-Shining by Electricity ina Self-Elevating Chair NEW shoe-shining machine, invented by Otis R. Hasty, of Elgin, Ill, is a combination of an ordinary chair and an electric elevator. You mount the chair at practically the normal height. The bootblack throws a lever. An electric motor drives some gearing which raises a rack-pinion con- stituting the supporting column of the chair. The foot rest is rigidly connected with this col- umn, so that it rises at — the same time. After rubbing on the paste, the bootblack plugs a short flexible cable to a shaft jutting out at the bottom of the machine. The shaft which is geared to the motor also, imparts its rotation to the flexible cable and to the cir- eae -+-Yellow sedi- | ment —tRed sedimerit Orange mix- ture mingle, the true color effects of the mixed pig- ments are at once ap- parent. This is by far the best method yet employed for teaching color effects to a class of pupils. Employing Deadly Gases Against the Sleeping Sickness Fly N British East Africa great annoyance’ has been caused by the tsetse-flies, a species closely allied to the ordinary house-fly, but which in that locality is considered particularly dangerous to health. In New Langenburg, a district recently acquired from the _ Germans, it has been impossible to maintain horses, cows or cattle of any description on account of the mor- tality caused by the diseases which the flies are said to carry. The extermination of the flies has therefore become a matter for Govern- mental consideration. . The latest suggestion awaiting experiment is the use of gases, poisonous to the flies. These, it is believed, could be carried across the fly-infested areas by the monsoons, in the same manner as the destructive gases are carried in trench warfare. Pigment ‘‘matches’’ dissolved in water to show the effects of blending different colors cular buffer at the end of the cable. The buf- fer speeds around and brushes your shoes in a twinkling. Such little time is required for the operation that one bootblack can attend to two patrons at a time, polishing the shoes of the first © while the paste on the second pair ‘is: “setting.” You don’t have to be an athlete to climb into this chair. An electric motor raises you to the proper height Popular Science Monthly German Trenches as Comfort- able as Houses “* ERMAN trenches taken by the enemy have excited con- siderable comment because of the complete manner in which they are fitted up. Many of these trenches have been found to be unaffected by the heaviest bombardment. Some of the sheiters taken had been ex- cavated to a depth of about forty feet. They had galleries one hun- dred and fifty yards long and seven feet high. Large rooms opened out from the galleries. Both galleries and rooms were lined with strong timber. Ventilation was afforded by oblique shafts. The exits, of which there were many, consisted of staircases. The steps were fitted with steel treads, and ramps having a gentle incline. -Wearing Spikes on Your Feet to ‘Prevent Slipping on Ice , VERYBODY knows the difficulty of “4 maintaining a foothold when walking on ice or sleet and slush-covered streets. A device which can be worn either on shoes or rubbers to prevent slipping has been invented by C. A. Anderson and G. H. Schepstrom of Illinois. Mr. Anderson, who is a shoemaker, noticed that every winter there was a demand for creepers but that few of the creepers on the market Not gave satisfaction to the wearers. having facilities to make the _ steel spikes nec- essary to con- struct creepers, he called for as- sistance on his friend, Mr. Schepstrom, who is a sheet metal worker. Together they produced a type of creeper which has dis- © tinct advan- tages over the ordinary kinds in use. The new creepers are fastened by straps in much the same way as are some skates. There are steel studs on both the sole and the heel which enable the wearer to stand securely in any position. boots or rubbers. A new ice-creeper which may be worn over shoes, It is strapped on like a skate The device is nothing more than a phonograph diaphragm and a horn which amplifies the weak sounds of the relay Applying the Principle of the Phono- graph to the Telegraph Sounder N long telegraph lines, the current coming into a station is generally so weak that it cannot even pull down the magnet of the loud-sounding instrument. The current can, however, operate a small magnet ona very sensitive telegraph instru- ment. By making this small magnet close a heavy battery circuit in which the loud sounder is placed, the sensitive instrument acts as a relay and overcomes the difficulty. Extra batteries and instruments are therefore needed at every station. In any large size telegraph sys- tem, the ex- penses of their upkeep are con- siderable. A very clever invention of R. A. and B: M. Grout,of Daven- port, lowa, does away with this expense by am- plifying the weak relay clicks directly by means of a diaphragm and horn such as are used in all phonograph instruments. The weak clicks are transmitted to the diaphragm whose vibrations act upon the air and shoot their corresponding sounds out through the horn. 880 — A lighter for starting fires without using paper. Into a decorative can holding. kerosene an asbestos mop is dipped. When lighted, the mop is held under the wood until it catches the flame Housekeeping Made Easy LEED The picture be- low shows a skein-holder for yarn. The yarn can be used di- rectly from the holder, if de- sired, without the trouble of winding it into the usual balls An ordinary tin pail decorated with hand paint- ing and used as a flower pot for the porch or liv- ing room, ivory-white lat- tice work on which gayly col- ored birds perch furnishes support for the plants This unique tea wagon is pro- vided with an electrical attach- ment under its metal cover 4 sf With this tiny grain mill you can grind your own corn-meal, a little at a time A new book-holder for the library table will please the automobilist 890 Housekeeping Made Easy Below: A_ vegetable dicer. It cuts potatoes, carrots, etc., in small cubes without extract- ing any of the juices Wy A sanitary case for the toothbrush. The tube of tooth paste is held in a clamp at the side. The base of the device is attached to the wall A spacious kitchen cabinet which will ac- commodate every kind of kitchen utensil. It even has a ventilated compartment for food QR AAA In center above: A bookcase which has been transformed into a dolls’ house for the nursery. Here the toys are kept dust-free and orderly In center: A combination step- ladder and stool with large round top. It folds up to four inches in width and weighs six pounds RN RAO KATANA RNG WH SANA AN % ae i "Carmenisnitnnamaanisa MME OLMOHD 6. 8 Matti ‘A light-weight magazine - holder Carved. wood figures are popular N made of hand-painted tin which is in decorations. Here a flower-holder decorative enough for an ornament is concealed by ‘a dainty lady doll 891 892 spite of the fact that it is safer than an_ enclosed chimney. . The builder of the house in the photo- graph worked out a novel effect by cutting windows through the brick to re- lieve the plain surface. Shutters were also provid- ed so that the chimney windows might be in per- fect harmony with those of the house proper. The windows are mere im- itations, the flue being built up on the inside to insure a perfect draft. However, arrangements have been made so that it is easy to get to the inside of the chimney through the window spaces, when re- pairs are necessary. Hang That Book from Your Shoul- ders and Read in Comfort OSEPH J. SLEEPER, of Philadelphia, had to consult a number of books of reference one day, and before he got through he was very tired. He then experimented with a shingle which he sus- pended about his neck by strings attached to the four corners. He found that he could rest his book on this and relieve himself from the weight, from the fatigue caused by stooping and from the eyestrain caused by reading a page not in proper focus. He could also jot down notes of reference without bend- ing over or otherwise in- conveniencing himself. Since that early ex- periment the inventor has perfected a book rest which can be ad- Popular Science Monthly A Chimney With Windows—But They Are Not Real CHIMNEY on the outside of a house is, in popular opinion, unattractive in To relieve the bareness of the brick wall of the chimney the builder provided dummy windows N_ Shipley A new book or music rest which may be suspended from the neck justed to individual requirements and which will support the weight of the book in such a manner that the hands are free. A lady who is anxious to knit for the soldiers may read and knit at the same time if her book is sup- ported on a rest. The device is construc- . ted of two parallel angle bars which are connec- ted with a sheet metal book-supporting tray. The tray will fold against the bars so that the book rest can be stowed away in a very small space when not in use. The book support may be used on the table in such a way that a paper or book may be propped up against it. A great convenience for the early morning commuter who likes to devour his news with his breakfast! The device might also prove exceptionally useful to the musical director. A Telltale Echo—It Repeated Secrets of the Confessional Church, Sussex, England, there was formerly an echo which re- peated sounds twenty- one times. The most remarkable of all mul- tiple echoes was that of the Simonetta Palace, near Milan, which re- peated the sound of a ° pistol shot fifty or sixty times. In the cathe- dral of Girgenti, Sicily, it is possible to hear, on the steps of the high altar, remarks in an undertone made at a place near the main entrance, a hundred feet distant. A con- fessional was once indiscreetly placed at this spot, and the dis- coverer of the echo is said to have amused himself by listening to the confessions of many fair penitents. Popular Science Monthly Incandescent Lamps May Now Be Used to Project Motion Pictures has always been more or less difficult to give motion pictures in places other than a regular theater equipped for the purpose. A lamp has been devised recently which will - make motion pictures possible in churches, schools and even in the home. There is nothing which equals motion pictures as a means of popular enter- tainment. Many a small fair, held for charity, would be more successful from a financial point of view if the added attraction of lively motion pictures could be offered. _ A low voltage con- centrated filament lamp has been de- veloped which may be used with a new lamphouse designed . especially for motion. picture use... The lamphouse . contains a double lamp holder with several adjust- ments, areflector and two sets of condens- ers, one for stereopticon and the other for motion picture use. se A compensator with ammeter and resist- arice regulator is used for alternating cur- rent and a small rotary converter for direct current. consumed is not important a specially ‘designed resistance with ammeter may be used on direct current. All conditions which might make op- eration difficult may be met by the use of this lamp and Reflector adjusting screw lamphouse.