The
MECHANICS
I y..^—..^. .. A
IS
COMPISIB
Processes for Arti
In Every Trade « .* <t
K. Wl N i
GIFT OF
.V. K. '^interhalter
UNIVERSITY FARM
R E V I SEP UP-TO-DATE EDIT I ON
THE
Mechanics'
Complete Library
OF ,
MODERN RULES, FACTS, PROCESSES, ETC,
Facts About Electricity— How to Make and Run Dynamos—
All About Batteries, Telephones, Electric Railways and
Lighting— Engineering Explained— Rules for the In-
struction of Engineers, Firemen, flachinists
Mechanics. Artisians and all Craftsmen-
Tables of Alloy -Useful Recipes— In-
formation Concerning Glass, fletal,
Wood Working, Leather, Arti-
ficial Ice-making, Chemical
Experiments, Glossary
of Technical Terms,
Etc., Etc.
FIVE BOOKS IN ONE
^w COMPILED BY
THOMAS F. EDISON A.M., and CHARLES J. WESTINGHOUSE
COPYRIGHT, 1890, BY LAIRD & LEE
COPYRIGHT. 1895. BY LAIRD & LEE
CHICAGO
LAIRD & LEE, Publishers.
1897.
CONTENTS.
Accidents by Shafting, to prevent 130
Accidents from Running Machinery, prevention of 127-130
Accidents, how to prevent 147
A'r-Brake, Westinghouse Automatic 39- 74
Alloy, a new 226, 284
Alloys and Solders i8d
Alloys, table of principal 424
Altitude above the sea level of various places in the United States 424
Aluminum, how to solder 368
American Steamers, fast 189
Ampere the (electrical measure) 538
Ampere' s Rule 487
Analysis of Boiler Incrustations 155
" Ancient " Winters 559
Apprentice^points for 301
Architects, laws effecting. . . '. 442
Architects, etc., pointers for 420, 421
Areas of Circles " 351
Armor Plates, tests of 215
Artesian Wells, valuable 344
Ash Sifter, how made 382
Atmosphere, effects on bricks 437
Atmosphere, estimated mean pressure 55
Automatic Sprinklers, care of 185
Avoirdupois weight 356
Babbitt Metal, composition of 369
Ball, cast iron, weight of 282
Ball, how to turn a 209
Bank of England Doors, the 560
Barrels, how made 234
Basswood Moldings 445
Batteries, closed circuit (electrical) 536
Batteries, electric 536
Batteries, galvanic 536
Batteries, open circuit (electrical) 536
Batteries, primary (electrical) ^ 536
Batteries, storage or secondary (electrical) 537
Batteries, voltaic 536
Bell Time on Shipboard 555
Belting, camel's hair 289
Belting, how to calculate'speed 332
Belting, notes on 80
Belting —Rules , 80-82
Bessemer Process, real inventor of 220
Blowing Off Under Pressure 152
Boilers (see Steam Boilers) 45
Boiler Circumferences, points on 88
Boilers, Steam 45
Boiler Tubes, cleaning .- 155
Boiling 145
Bolts, weight per 100 207
Brass, cleaning 155
Brass, its treatment - -323~~325
Brass, how to lacquer 219
Brass Castings, hard and ductile 186
Brass, weight of sheet 196, 197
Breaking Strains of Metals 282
Bricks, effects of atmosphere upon 437
Bricks, made from refuse of slate quarries 337
Bricks, number of, to construct building 439
Hand Saw, how to select a 292
Bronze, how to make malleable 288
Building Blocks Made of Corn Cobs 445
Builders, points for 411-413
Buying Oil and Coal 317
Cables, submarine 278-282
Calcimine, how to prepare 445
Calking - 3M
CamePs Hair Belting 285-289
Cans, flat- top, size and weight 4^
Carpenters, number m London, etc 337
Cast Iron Columns 3^7
Cast Iron Columns, safe load for. , 349> 35°
Cast Iron Columns, safety load • .362-364
Cast Iron Columns, weight of 353> 354
Cast Iron Piles, ar^on of sea-water 210
Cast Iron Pipes, weight of. 410
Cast Iron, weight of per lineal fov.\v 205
Cathedrals, dimensions of 44!
Celluloid Sheathing ^5
Cement, a new 284
Cement, a reliable 446
Cement, as used in Paris 044
Cement for Granite Monuments 304
Cements, useful ^4
Centigrade and Metrical Equivalents 283
Chicago Auditorium, description 416-418
Chimneys, how to cure smoky 459-461
Chimney, one that will draw 369
Chimneys, sweating of 4-8
Chimneys, table of go
Chinese Cash 4r4
China, cost of living in 367
Chisels, Cold 75- 77
Circles, area of '."... 35 r
Circles, circumferences of ^52
Cisterns, cylindrical, capacity of 292
Cisterns, cylindrical, capacity per foot 365-
Cleaning Brass x -$
Clock Movement, self-winding 307-310
Closed Circuit Batteries (electrical) 536
Coal, a large lump of 2Q7
Coal, consumption of by railroads 430
Coal, how combustion is produced 291
Coaling Ships in West 1 ndies 384
Coal, steam x^i
Coins of Different Countries x 72, 1 73
leather, making japanned 218
Colors, suggestions for 441
Cold Chisels 75- 77
Combustibility of Iron Proved 271
Combustion, spontaneous 136-139, 297
Combustion, spontaneous, liable to 291
Common Names of Chemical Substances 563
Compass — Why it varies 227
Conductors (electrical) 535
Copper, deoxidized . . . .^ 217
Copper, tenacity and loss 336
Copper, weight of sheet 196, 197
Corliss Engine Valves, how to adjust 27
Counter-boring, tool for 311
Crystallized Tin Plates 373
Cubic Measure 355
Cube Roots, tables of 107-110
Dam, largest in the world 559
Dampers, Oval 400
Deafness caused by Electric Lights 297
Deep Soundings near Friendly Islands 414
Decimal Equivalents 187
Decimal Equivalents for inches, feet, etc 442
Decimal Equivalents for ounces and pounds 442
Deoxidized Copper 217
Dies, metal working 326-331
Definitions and useful terms 91
Dry Rot in Timber 429
Dynamo, the, how to make one 478-531
What a Dynamo is 478
Faraday's Discovery 478
The Galvanometer 479
How to make one *. 479
Permanent Magnets 481
Testing the Galvanometer 482
Experiments with one 483
Experiments with a Magnet 485
The Magnetic Poles 486
Currents produce Magnetism 486
Ampere's Rule 487
The first Dynamo 488
Clarke' s Dynamo 489
Function of the Commutator 490
Hjorth's Dynamo 492
Sieman's Armature 493
Currents not Continuous 494
Magnetism produces Heat 495
Pacinotti's Ring Armature , 496
Patterns for a Dynamo 497
Pattern for Armature 498
Drawings for Armature $09
Patterns for Field Magnets 501
Drawings for Field Magnets 500-503
Patterns for Standard 504
Drawings for Standard 504
The Castings 505
Assembling the Castings 506
The Bearings 510
The Commutator 513
The Driving Gear 516
Wiring the Dynamo, 518
Wiring the Armature 518
Wiring the Field Magnets 520
Attachment of Wires 525
The Brushes 526
Binding Screws and Connections 528
The Complete Dynamo 531
Dynamo, the, what it is 478
Dynamo, Management of the 532
Eccentric, Locomotive, how to set 89
Economy in Use of Injectors 131
Eiffel Tower, the 437
Elbow, four piece, to describe a pattern for 383
Elbow Angles, table of height 380
Electric Batteries (see batteries) 536
Electric Experiments 536
Electrical Measurements 538
Electricity, development of 211
Electricity Developed by Chemical Action 535
Electricity Simplified 533
Electricity, frictional 534
Electricity, negative 534
Electricity, positive 534
Electricity, voltaic and galvanic 535
Electricity, what is it? 535
Electric Hand Lantern 242
Electric Lights in Germany 45b
Electric Lights, largest in the world 476
Electric Light, some figures - . 238
Electric Machine 535
Electric Railroad 282
Electric Street Railways, cost of 228
8
Electro-Magnetism 486
Emery Wheels, value of 273
Engines (see Steam Engines) 23
Engines, comparative economy of high and low speed 116
Engines, manipulation of new 167
Engines, triple expansion 168
Engine, use of Indicator 30- 42
Engineers, a warning to 189
Engineers, pointers for. ." 169
Engineers, valuable information for 161
Experiment, an interesting 319
Experiment, electrical 536
Explosion of Hot Water Boiler 391-394
Explosions, boiler in Germany 185
Expansion of Substances by Heat 206
Eve Trough, making 379
Feed Water Heaters 84
Ferrules, how to draw 305
Figures, valuable 448
Filter, a cheap 368
Fire Grate Surface, rule for finding 47
Firemen, rules for 140
Fire Proofing Wood Work 440
Flange Joint, how to make a strong 122
Flaring Articles with Round Corners 376-379
Flaring Oval Articles, patterns for 375, 376
F! :xible Glass 237
Floor, how to make a good 425
Floors, how to wax 338
Floors, painting 430
Floors, painting and varnishing 456
Flower Stand, a wire 385
Foaming in Boilers 144
Forests of the United States 423
Forth Bridge, description of the new 558
French Cubic Measure 355
French Long Measure 358
French Square Measure 357
French Weights '. 356
Friction of Water in Pipes 55
Fuel, heating powers of 211
Funnel Marks of the Principal Atlantic and Transatlantic Steam-
ship Lines 554
Furnaces, facts about 461
Galvanic Batteries 536
Galvanic Electricity 536
Galvanometer, the 479
Galvanometer, ho\v to make 479-483
Gamboge, how prepared 562
Gas for Locomotives 165
Gas Leakage, how to detect it 555
Gauges, Railway . 170
Gauges, Steam 146
Gear Teeth, how to prevent breaking 269
Gearing, high speed 290
Geometry, practical for mechanics 98
Glass Cutting by Electricity 296
Glass, flexible 237
Glass, frosted.. .- 448
Glass, how to perforate 289
Glossary of Technical Terms 565
Glue for Damp Places 426
Glue, on the use of 436
Glue Paint for Kitchen Floors 436
Granite, polishing 342
Graphite, in steam fitting , 141
Grindstone, how to make a small .-.•„, 79
Grindstone Quarries 344
Grindstones, to find weight of. 423
Gun Barrels, browning them _ 297
Guns, large ones made 296
Hand-hole P lates 145
Hardware in Havana... 373
Heat, amount of, required to melt wrought iron 268
Heat, divisions of degrees 160
Heat, expansion of substances by 206
Heat Produced by Rapid Magnetization 495
Heat-proof Paints 408
Heat, what is latent heat? , . . . 157
Heating and Ventilation 386-390
Heating Power of Fuel 2x1
Heating, steam 154
Heating, steam -vs. hot water 462-464
Heating Surface of Boilers 47
Heating Surface, steam radiators 369
High-speed Gearing 290
Hip Bath in Two Pieces: 406, 407
Horse-power of Belting 82
Horse-power, nominal, indicated, effective 142
Horse-power of Steam Boilers — 46, 47
Horse-power of Steam Engines 23, 1 30
Horses, Strength of 559
Hot Water Systems 368
How to CaSt. a Face 284
Hudson Bay Company 344
Ice House, how to build 444
Incrustations of Steam Boiler 146
Indicator, Steam Engine 30- 42
Indicator, description 30
Indicator, method of indicating 31
Indicator, driving rigging 32
Indicator, diagrams 34
Indicator, uses of 35
Indicator, tables for 39
Indicator, taking diagrams 40
Indicator, special instructions 41
Indicator, computing horse-power 42
Injector, economy in the use of. 131
Injectors, how to set up 53
Injectors, suggestions regarding 53
Insulators (electrical) 535
Iron and Steel, average breaking strain 159
Iron and Steel Making in India 275
Iron Brick 428
Iron Castings, facts about , 23 c
Iron Castings, how to bronze 336
Iron, combustibility of, proved 271
Iron, different colors, caused by heat 305
Iron, flat-rolled, weight per foot 198-203
Iron, how it breaks 272
Iron in the Congo 296
Iron, Russian sheet 474
II
Iron, new method of bronzing 473
Iron, painting of.
Iron, removing rust
Iron, weight and areas of I9C
Iron, weigh t of sheet 196,19?
Isinglass, facts about *
Ivory Gloss, how to put on wood 3j
Japanese Lacquer for Iron Ship* 5
Japanese Water Pipes • 2I
Lacquer, Japanese, for iron ships 2-
Lap on Slide Valves ""
Latent Heat, what is it?
Lathe, how to gear for screw-cutting 3
Lathe Tools for Metals
Law Affecting Architects 4J
Law of Proportion in Steam Boilers • • ie
Law, Swiss Patent 277
Lead, ancient use of.
Lead on Roofs and in Sinks 35
Lead Pipes, caliber and weight *
Leather, new substitute for ^
Lightning Rods, uselessness of 5*
Lock , largest in the world 5 2
Telephones • ;••;•_; •"• *jj*
Locomotive, an experiment with one. ....:.-
Locomotive, eccentric, how to set *
Locomotive, gas for .
Ice Making, artificial I74
Locomotives in 1832 and 1888 74
ocg
Long Measure
Lubricating without oil • 3'
Lumber Measurement Tables
Lumber, oak, care of
Machinery, prevention of accidents by I27
12
Machinery, care of 143
Magnetic Poles, north and south 480
Magnets , 486
Magnetism 531
Magnetism, Electro 531-478
Magnetism, effect on watches 230-234
Magnetism, Faraday's discovery 478
Magnetization, rapid, produces heat 495
Mahogany, value of 341
Malleable Iron, to tin 370
Management of a Dynamo 532
Manilla Rope Transmission 184
Mathematics, definitions and useful numbers 91
Measures of Different Countries 171
Measurements, electrical 538
Melting Points of Metals 285
Mensuration 94
Metals, meltings points of 285
Metals, value of. 287
Metrical and Centrigrade Equivalents 283
Mica, uses of . .*. 468
Mineral Wool 225
Mitering, perfect 449-451
Miter, to describe a 382
Molders, a Valuable point for 283
Monetary Units and Standard Coins of Different Countries... 172, 173
Mortar Making 427
Mud Drums, pitting of 159
Nails, ten-penny, what a pound will do 427
Nails, number of, in a pound 337
Natural Gas, use of, in cupolas 284
Nickel Plating 226
Nickel Plating Solution 226
Nickel Plating, to polish 374
Non-conductors (electrical) 535
Non-magnetizable Watches 218
Novel Drawing Instrument 403
Nuts, square, number in a keg 268
Nuts, hexagon, number in a keg 269
Oak Lumber, care of 339
13
" Of Course," for engineers 26
Ohm, the (electrical) 53^
Oil and Coal Buying 3J7
Old Tins No Longer Useless v 37*
Open Circuit Batteries (electrical) 536
Oval Damper, how to make 4°°
Oval of Any Length, how to strike 385
QV . ; «,v^, S<2.v,9/:e aa<i Circle 39°
Paint, a durable black - 4°7
Paint, a valuable preservative *°°
Paint, heat proof 4°8
Paint Work 4l8
Painting Floors 43°
Paper Holder, an ornamental.. 3°6
Paper Makers, valuable points for 5.6*
Patent Office, United States, rules and regulations 545
PATENTS, a few points for inventors regarding 545
Correspondence with Patent Office 545
Applicants 545
In case of death of inventor 54^
In case Patent is assigned 54°
Joint inventors 54$
Foreign Patents 54°
The Application - 546
The Petition 547
The Specification 547
The Oath 548
The Drawings 549
Kind of paper 549
Size of sheet 549
Regarding Drawings 55°
The Scale 55<>
The Model 55*
Attorneys 551
Patent Office Fees 55*
Patent Laws, Swiss 277
Patterns for a Dynamo 497~5°5
Pattern for a Tapering Square Article 4°4
Pattern for a T Joint 4°*
Patterns, how to mend 2*
Pattern Making, hints on 2&
Pattern Making, notes on 3!g
Pavements 447
Pipes, cold water supply 431-434
Pipes, cast iron, weight of 410
Pipes, lead, caliber and weight . ' 334
Pipes, steam, a non-conducting coating for 134
Pipes, to find amount for heating buildings 434
Pipes, how to thaw out 126
Pipes, steel, tests of 310
Plane Iron, how to sharpen 340
Planing Machines 22}
Plaster, a new wall 446
Plastering, estimating cost of. 413
Plaster for Moldings 457
Pointers for Success in Business 556
Poles, the magnetic 480
Power, transmitting by vacuum : . 136
Pressure, atmospheric mean 55
Primary Batteries (electrical) 536
Principles of Boiler Construction 148
Proportions for Steam Boilers 166
Proof of the Earth's Motion 227
Proposed Engineering Feat 435
Pulleys, rule for width and diameter 82
Pumps (see Steam Pump) 54
Pumice Stone, how made 266
Rails, steel 350
Railroads, consumption of coal „ 430
Railroads, electric, in Japan 325
Railroad, electric, largest in country 282
Railroad Signals 183
Railway Gauges of the World 170
Railway Transit, rapid 134
Redwood Finish 446
Reservoir, tapering, round-cornered one . 401
Rivets, boiler, number per loo-pound keg 336
Rivets, weight of 204
Rock, cost of excavating - . . 428
Roof Framing, hip and valley. 455
Rope, how to select 293
Rope, length per coil, and weight 288
15
Rope Transmission in England 4
Rot in Timbers _ 43
Rule to find area steam piston of pumps 56
Rules for Belting:
To find length and width 80
To calculate horse-power 82
To find width of pulley 8»
To find diameter of pulley 82
To find number of revolutions 82
Rule— To find capacity of water cylinder of pumps 56
Rule— To find diameter of cylinder for required horse-power. 24
Rule — To find diameter pump cylinder 55
Rule — General rule for all classes of boilers 49
Rule— To find height for discharging given quantity of water. 51
Rule— To find fire grate surface of boiler 47
Rule — To find fire grate surface of locomotive boiler 47
Rule— To find heating surface boiler 47
Rule— To find heating surface of locomotive boiler 47
Rule — To find horse-power of boiler 46
Rule— To find horse-power locomotive boiler 47
Rule— To find indicated horse-power of engines 24
Rule — To determine lap on steam side slide valve 25
Rule— To find horse-power for elevating water ,56
Rule— To find quantity of water to be discharged 56
Rule— To find quantity water elevated 55
Rule — To find pressure of a column of water 54
Rule— To find size orifice to discharge given quantities water 56
Rule for Firemen • 140
Rules and Regulations for Properly Wiring and Installing
Electric Light Plants 539
Moisture danger 539
Earth danger 540
Ignorance, etc • 540
Consulting Engineer 540
Conductors 540
Sectional area 540
Acr ^sibility 540
Insulate * • 540
Maximum tei. ~^ature . 540
Distance apart « 541
Inflammable structures 541
i6
Metallic armor « ... 541
Joints , . . . . , , 541
Gas and water pipes 541
Overhead conductors . 541
Lightning protectors . 541
Insulation resistance . . 542
Switches 542
Construction and action , . 542
Insulating handles , 542
Main switches 542
Switch boards 542
Electrical fitting , ..... 54*
Cut outs » , . . 543
Imperative use of 543
Situation « . . T . . . . - . 543
Portable fittings . . . 543
Arc lamps „.„...<.. 543
The dynamo. ....... 544
Batteries , .. .. 544
Maintenance „ . . . 544
General ......... 544
Rust, how to remove from iron . „ 222
Rust-Proof Wrapping Paper. ....«....=. . . . . , 406
Rusty Steel, to clean ... ,...<= . , . c . . . < *..<>.....;..,-. 238
Safety Valves . c „......„. . . . «. , . . ........ . . .49, 50
Safety Valve, rule for weights c ... c .......... 119
Saturated Steam, properties of. , . ...... .0 150
Screw Auger, inventor of 405
Screw Cutting, how to gear a lathe for no
Screw Drivers, an improved ...... 229
Screw Heads, how to bury out of sight. 455
Screw Making at Providence , 298-300
Screw Threads, table of gears for cutting. ...... c 243-264
Sea Water, action of on, cast iron piles. ...» ..Oo..ot .............. 210
Watch, facts about 325
Shafting, accidents by 130
Shafting, an easy way to level « 307
Shafting, belting at right angles .....«, .„ 306
Shafting, things to remember. ........o..o..0eo.eooec..o. ....320 321
Sheathing celluloid . o........... 135
Shingles, to calculate number of.. .»...„ „<>. 44-
Shop Kinks, useful , . .T 395-398
Signals, railway 183
Sleepers Used by World's Railroads 409
Slide Valves, how to set 24
Slide Valves, setting of 87
Smoke, how formed 156
Smokey Chimneys, how to cure 459-461
Soda Ash in Boilers 150
Soldering 4jn
Solder, cold 370
Solders and Alloys 186
Soldering, points on ...... 473
Specific Gravity, table of i-4
Spindle-milling Machine 390
Spontaneous Combustion 136-297
Spontaneous Combustion, liable to 291
Square Measure 357
Square Roots, table of 107-1 10
Steam as a Cleansing Agent 168
Steam, an invisible gas 126
STEAM BOILERS, analysis of incrustations 155
Boiling 145
Blowing off under pressure 152
Care of 55
Calking 124
Cleaning tubes 155
Foaming 144
Hand-hole plates . 145
Horse power •:'. 46
How plates are proved 179
How to prevent accidents 147
How to test 162
Importaant to those operating 147
Incrustations of 146
Kinds of 45
Largest in America 122
Law of proportions 160
Marine 47
Mistakes in designing 158
Principles of construction 148
Proportions for, 166
Rules for 47, 32
iS
Safe working pressure flues 184
Scale in 163
Stopping with a heavy fire 154
Table of safe working pressure 153
Testing plates 166
The total pressure . ." 152
Treatment of. 115
Tubular 47
Weight of circular heads 335
Steam Coal 151
Steam Engine 23
Actual horse power 23
Comparative economy high and low speed 1 16
Corliss valves, how to adj ust 27
Expansion by lap 25
Future of 164
Horse-powers 23, 142, 143
Indicated Horse-power 23
Indicator 30- 42
Manipulation of new 162
Mean pressure in cylinder .. 23
Nominal horse-power 23
Rules 23 25
Slide valves, how to set 24
Slide valves, setting of. 87
Theory of 112
The world's 290
Triple expansion 168
Steam Fitting, use of graphite 141
Steam for Heating 58
Steam Gauges 146
Steam Heating 154
Steam Radiators, heating surface of 369
Steam Pipes, for heating buildings 434
Steam Pipes, how to thaw out 126
Steam, properties of saturated 150
Steam Pumps, suggestions 54
Steam Pumps, to find diameter cylinder 55
Steam Pumps, to find quantity Water elevated ... . 55
Steam, super-heated 146
Steam vs. Hot Water Heating 462-464
19
Steamers, Fast American 189
Steel, chemical or physical tests for 212
Steel, how to anneal 223
Steel, notes on working of 267
Steel, to clean rusty 238
Steel Pipe, tests of 310
Steel Punches, tempering 208
Steel Rails, used as girders 350
Steel Sleepers, rivetless 184
Steel Square, ho\v to use 372
Steel, suggestions to workers 213
Steel, the secret of cast steel 274
Steel, weight of sheet 196, 197
Steel, when hardened 139
Steel, why hard to weld 304
Stone, natural and artificial 365
Stone, crushing strain 365
Storage Battery, how to -make one 312
Storage or Secondary Battery 537
Strainer, rain water '..... 399
Street Railways, electric 22?
Strength of Materials 359-361
Switching from an Engine Cab 183
Submarine Cables 278-282
Superheated Steam 146
Surveying Measures 358
Sycamore 439
Tables,
Alloys , 424
Chimneys 90
Heating surface per horse-power 46
Cube and square roots 107-116
Density of water 123
Diameters, high and low pressure Cylinders 122
Difference of time from New York 180-182
Friction of water in pipes 55
Horse-Power transmitted by belts 120, 121
Lap according to travel slide valve 25
Length and number tacks per pound 182
Proportions cylinder tubular boilers 48
Properties saturated steam 150
Safe working pressure iron boilers 153
Safety-valves, capacity 51
Chimneys, regard to horse-power 90
Size, capacity standard puuws ... 57
Saving by feed water heater . %b
Specific gravity lOo
Square and Cube roots 107-1 10
Strength belting material 83
Universal taps 265, 266
Tacks, length and number per pound 182
Tanks, how to calculate capacity 335
Taps, universal, table for making 265, 266
Temperature, indicated by color of flame 49
Tempering Steel Punches 208
Testing Armor Plates 215
Testing Boiler Plates 166
Te^eing Exterior Stains 444
Tests for steel, chemical or physical 212
Thermometers, how made 300
Thermometer Scales 302, 304
Thermal Unit/^jxplanation of . . 155
Theory of Steam Engine 112
Things That Will Never Be Settled 293
Things Worth Knowing 294
Timber, a colossal stick of 457
Timber, dry rot in 429
Timber, in favor of small 343
Timber, properties of 366
Timber, rot in 438
Timber, seasoning 435
Time, difference from New York „ 180-182
Tin, modern uses of. 466-468
Tin Plates, crystallized 373
Tin Plates, endless 373
Tin, sizes and weights of 333
Tinning by simple immersion. . . „ 434
Tinning, improved process of 469
Tool for counter-boring 311
Tools, how to anneal small 187
Tools, how to detect iron and steel 173
Tools, how to keep 229
Tools, lathe for metals 77
21
Tracing Paper, how to make 208
Trees, the annual ring in 419
Tubes, solid drawn 224
Turning or Lathe Tools for .Metal 77
Universal Taps 265-266
Useful Cements 134
Useful Numbers 3*5-317
Useful Numbers and Definitions 91
Useful Receipts 374
Useful Shop Kinks « 395-398
Vacuum, transmitting power by 136
Valuable Figures 448
Various Locations of the Capital of the United States 557
Varnish, to make it adhere to metals 282
Varnish, removal of old 441
Varnishing and Painting Floors 456
Ventilation and Heating 386-390
Ventilation of Buildings 451-454
Ventilation, hints on , . 422
Vibration, how to overcome 185
Volt, the (electrical) 538
Voltaic Electricity 536
Voltaic Batteries (electrical) 536
Common Woods, tensile strength of. 208
Watch and Learn . 216
Watches, effect of magnetism upon 230
Leather, making japanned 218
Watch Wheels, number of revolutions 283
Water, density of 123
Water, friction of in pipes 55
Water, simple tests for 294
Water, useful information about 54
Water Pipes, Japanese 210
Weight, avoirdupois 356
Weight of Bolts per ico. 207
Weight of Copper 196, 197
Weight 'Cast Iron per Lineal Feet ^205
Weight, cubic foot substances 346-348
Weights, French -. 356
Weight of Iron 190-195-196-197-108-203
Weight of Rivets and round-headed Bolts 204
Weight and Specific Gravity Metals 286
Weight of Sheet Brass 196, 197
Weight oi Sheet Steel 196, 197
Welding, a Russian process 370
Welland Canal, the • 561
Wells, artesian 344
Leather, making japanned 218
Westinghouse Automatic Brake 59
Description 59
Air pump 6X
Triple valve 63
Engineer' s brake-valve 65
Pump governor 67
Equalizing valve 68
Instructions 69
How to apply 71
How to release 71
Brake power 73
Car levers 74
When a day's work begins : 289
Hydraulic Rams 564
Window Glass, how large cylinders are cut 344
Window Glass, number lights in a box of 50 feet 270
Wire Manufacture, new process ., ., 409
Wood, a polish for 447
Wood, a very durable 443
Wood, preservation by lime 443
Woods, weight of 333
Wooden Beams, safe load for : 345
Workshop Jottings 322
Wrapping Paper, rust-proof 406
Zinc, as a fire extinguisher 381
Zinc, how to polish 4*4
23
THE STEAM-ENGINE.
The term " Horse-power " is the standard measure of
power as applied to steam-engines. This unit of power has
been adopted by all manufacturers of steam-engines in all
parts or the world.
The term originated with Watts, the so-called inventor of
the steam-engine. He demonstrated that a horse could work
8 hours a day continuously, traveling at the rate of 2^ miles
an hour, raising a weight of 150 pounds ipo feet high by
means of a block and tackle. Reducing this to equivalent
terms, a horse could raise 150 pounds at the rate of 220 feet
per minute, or 2j^ miles an hour, or 33,000 pounds one foot
per minute. Thus, a horse-power is the power required to
raise 33,000 pounds one foot a minute. There are three
kinds of horse-power referred to in connection with engines,
* nominal" "indicated" and "actual"
The nominal horse-power is found by multiplying the area
of the piston in inches by the average pressure, and multiply-
ing this product by the number of feet the piston travels in
feet per minute, then dividing this last product by 33,000.
The quotient will be the nominal horse-power of the engine.
The indicated horse- power is found by multiplying together
trie mean effective pressure in the cylinder in pounds per
square inch, the area of the piston in square inches and the
speed of the piston in feet per minute, and dividing the prod-
uct by 33,000.
The actual horse-power i» the indicated horse-power
minus the amount expended in overc< ming the friction. The
following is a general rule for calcula ing the horse-power of
an engine:
RULE. — Multiply the area of the pi ton in square inches ,
the mean pressure of the steam on the nston per square inch,
and the velocity of the piston in ft^.t per minute, together^
and divide this product by 33,000. 7 \: quotient will be the
horse-power.
The mean pressure in the cylinder, when cutting off at
stroke, equals boiler pressure x .597
x .670
x .743
K ' x -847
# «. x .919
x %&
x .992
24
TO FIND THE DIAMETER OF A CYLINDER OF AN ENGINE
OF A REQUIRED NOMINAL HORSE-POWER.
Divide 5, 500 by the velocity of the piston in feet per minute,
and multiply the quotient by the required horse-power. The
product will be the area of piston in square inches. From
this the diameter can be obtained by referring to table of areas
of circles.
TO DETERMINE THE EFFECTIVE POWER OF AN ENGINE BY
AN INDICATOR.
Multiply the area ot the piston in square inches by the
average force of the steam in pounds; multiply this product by
the velocity of the piston in feet per minute ; divide this last
product by 33,000, and j70 of the quotient will be the
effective power.
The travel in feet of a piston is found by multiplying the
distance it travels in inches for one stroke by the whole
number of strokes per minute. Dividing this product by 12
gives the number of feet the piston travels per minute.
THE SLIDE VALVE.
How to set a slide valve. — Place the crank at the center,
and the eccentric at right angles with the crank; then put
the valve in the center of its travel, and the rocker plumb at
^ght angles with both cylinder and crank-pin ; when this is
«fone, adjust the valve-gear to its proper length, then move
the eccentric forward until the valve has the desired amount
of lead; make the eccentric fast in this position, and turn the
crank around to the other center, and see if the lead is equal;
if so, the engine will run all right. In case the lead is not
equal, equalize it by moving the eccentric slightly back and
forth.
Where the lead is unequal on account of wear, the travel
of the valve may be equalized by placing lines of brass or tin
behind or in front of the box which connects the valve-rod
with the rocker. The " outside lap " means steam lap ; the
" inside lap " means exhaust lap.
To compute the stroke of a slide valve. — To twice the lap
add twice the width of a steam port in inches, and the sum
will give the stroke required.
Half the throw of the valve should be at least equal to the
lap on the steam side, added to the breadth of the port. If
this breadth does not give the required area of port, the
throw of the valve must be increased until the required area
is attained.
25
By referring to the following table, the desired lap may be
found if the travel of the valve is known:
Travel of
the valve
in inches.
The travel of the piston where the steam
is cut off.
1 i A 4
\-'l 3
I 1?
The required I.AI-.
22
3
31
4
I £
if
2
2 i
2ft
44
f
1!
1 4
To find how muck lap must be gii-en on (lie steam side of
a slide valve to cut off the steam at any given part of f/ie
stroke of the piston. — From the length of stroke of the piston
subtract the length of the stroke that is to be made before
the steam is cut off; divide the remainder by the stroke of the
piston, and extract the square root of the quotient; multiply
this root by half the throw of the valve; from the product
subtract half the lead and the remainder will give the lap
required.
Expansion by lap, with a slide valve operated by an eccen-
tric alone, cannot be extended beyond one-third of the stroke
of a piston without interfering with the efficient operation of
a valve; when the lap is increased, the throw of the eccentric
should also be increased.
The lap on the steam side must always be greater than
that on the exhaust side, and this difference ruust be in-
creased the higher the velocity of the piston, for, in fast-run-
ning engines, also in locomotives, it is necessary that the ex-
haust valve should open before the end of the stroke of the
piston, so that more time can be allowed fur the escape of
steam.
26
"OF COURSE" FOR ENGINEERS.
Of course you will always start your engine slowly, so that
the air and water condensation can be expelled from your
cold cylinder; then you will gradually bring it to its regular
speed.
Of course you will be sure to keep open the drip cock,
both in the front and back heads of the cylinder, when the
engine is standing still, and never close them until all the
winter has dripped out.
Of course you will never let in any oil or tallow to your
cylinder until it is made hot by the steam.
Of course you will be careful not to put in too much oil at
any time, knowing, as you do, that it will be sent to the feed-
water and cause your boiler to prime and foam.
Of course you will always oil up before starting your
engine.
Of course you will always keep your piston and valve-pack-
ing in a bag or clean drawer, so as to keep sand, dirt or other
grit from becoming attached to it, and so cut or flute the rods.
Of course you will not use new waste to wipe up the dirty
oil from the stub-ends, crank-pins or cross-head guides, and
then use the same waste to polish --up the bright and finished
work.
Of course you will exercise great care in adjusting the
packing in steam-cylinders.
Of course you know that when you generally pack the
piston packing, both cylinder and packing are cold, and if they
are screwed or wedged in very tight while in this condition
that the expansion, when exposed to the heat of the steam,
will induce great rigidity.
Of course you understand, if this is so, the oil or lubricat-
ing substance cannot enter between the surfaces in contact,
and that great friction, heating and cutting will be the result.
Of course you are aware that when packing loses its elas-
ticity it is no good, and should be removed.
Of course you know that piston or valve-rod packing should
never be screwed up more than sufficient to prevent it from
leaking, and that the softer the packing the longer it will last
and the better your engine will run.
Of course yo'u have tried that little trick of screwing the
packing up tight when it is first inserted in the boxes, and
then slacking the nut off to allow the packing to swell when
exposed to the heat of the stc m
Of course you will read pages 53, 88, 90, 95, 97 and 103 in
this book.
27
HOW TO ADJUST AND SET CORLISS ENGP'S
VALVES.
The original crab-claw valve-gear, as used by the inventor,
Geo. H. Corliss, has been gradually superseded by the im-
proved half-moon valve-gear, used on the Reynold's engine
and other prominent Corliss engine builders.
This difference between the old and new style of valve
applies only to the steam-valves, as, in both cases, the ex-
haust-valves open toward the center of the cylinder.
In the Corliss valve-gear (sometimes called "detachable
valve-gear") the action of the- steam-valves is positive, the
direct action of the working parts of the engine opening
them at the proper time, and keeping them open until the
connection with the engine is detached or broken, and the
hook tripped by the working of the cut-off cams. The steam-
valves are closed by vacuum dash-pots (sometimes by springs
or weights). The cut-off is automatic and is determined by
the lequirements of the load on the engine, so that the cut-
off cams do not always trip the hook at the same point, as
they are moved by the governor.
To those unfamiliar with the Corliss valve-gear, it ap-
pears a very complicated affair, yet, in reality it is very simple,
and is more easily adjusted than the ordinary slide-valve.
To understand the simplicity of the Corliss valve-gear, the
four valves (two steam, two exhaust), must be considered as
the four parts — or edges — of the common slide-valve, that
is, the working edges of the two steam- valves are equivalent
to the two steam edges of the slide-valve, and the working
edges of the two exhaust-valves as equivalent to the exhaust
edges of the slide-valve.
The principle is the same in the two styles of valves —
Corliss and slide — but the difference comes in the adjustment,
for the slide-valve is a solid valve, and any adjustment of one
part affects the whole, while with the Corliss valve each
part is susceptible of an individual and separate adjustment,
which can be made, if necessary, while the engine is work-
ing, without shutting down. The eccentric works the valves,
and are connected with them on the Corliss gear, by means
of the wrist plate, cnrrier-arm, rocker-arm and reach-rodj
Besides imparting motion to. he valves, the wrist-plate
modifies the speed of travel at different parts of the stroke,
giving a quick and accelerating speed when opening the
steam-valve, and a quick opening and closing of the exhaust-
28
valve, botli steam and exhaust-valves being at their slowest
speed when closed.
First, remove the back-leads or back-caps of the four valve-
chambers; when this is done the engineer will find guide lines
on the ends of the valves, and also on the ends of the valve-
chambers. The lines on the steam-valve will coincide with
the working edges of the valve, and those on the steam- valve
chamber with the working edges of the steam-ports. Guide
lines will also be found on the exhaust- valves and ports.
The wrist-plate is located on the valve-gear side of the cylin-
der, in a central position, between the four valve-chambers.
On the stand, which is bolted to the cylinder, will be found
a deeply scribed line, and on the hub of the wrist-plate, three
other lines, which show the center of the wrist plates, and
the limits of its travel or throw.
To adjust the valves, the reach-rod which connects the
wrist-plates with the rocker-arm, must first be unhooked; next
place the wrist-plate in its central position and hold it there.
All the connecting-rods between the steam and exhaust
valve-arms and the wrist-plate, are made with right and left
hand threads on their opposite ends, and furnished with jamb-
nuts, so that the rods can be easily lengthened or shortened
by merely slacking the jamb-nuts and turning the rods.
In this manner, set the steam- valves so that for every 10
inch diameter there will be ^ inch lap, and for every 32
inch diameter ]/2 inch lap, other intermediate diameters in pro-
portion to these distances.
Set the exhaust-valves for every 10 inch diameter of cylin-
der with ~fa inch lap, and for 32 inch diameter J/£ inch lap.
Double these distances for condensing engines.
The lines on the valves which are nearer the center of the
cylinder than the lines on the valve-chambers show the lap
on both steam and exhaust valves.
After the valves have thus been adjusted, turn the wrist-
plate to the extreme limits of its throw, and adjust the rods
connecting the steam-valve arms with the dash-pots, so that,
when the rod is down as far as it will go, the square steel
block on the valve-arms will just clear the shoulder of the
hook. The adjustments of these connecting rods must be
properly made, for if too long the steam-valve arm will be
bent or broken, and if too short the valve will not open, be-
cause the hook will not engage.
Now hook the engine in, loosen the eccentric on the shaft,
and turn it over, adjusting (he eccentric-rod so that the lines
29
on the hub of the wrist-plate, which show the limits of its
travel and throw, will coincide with the line scribed on the stand.
Place the crank on its dead-center, and turn the eccentric
in the direction which the engine is to run, so that the steam-
valve will show an opening of ^ to l/% of an inch (depending
on the speed at which the engine is to run — the faster the
speed the more lead it requires). The line on the valve,
which is nearer the end of the cylinder than the line on the
valve- chamber, shows the opening required, which is the
" lead " or port opening when the engine is on its dead-center.
Now secure the eccentric, or the shaft, by tightening the set-
screw, and throw the engine over to its other dead-center,
carefully noting if the other steam- valve shows the same
opening or lead. If it does not, adjust it properly by length-
ening or shortening the connecting-rod from the valve-arm to
the wrist-plate.
The exhaust-valves are adjusted in the same manner.
The directions just given are for the half-moon style of valve-
gears, which open from the center of the cylinder. In cases
of the crab-claw, or any other style which open toward the
center of the cylinder, the method of adjustment is the same
as given above; but, with the difference that the lap on the
steam-valves will be shown when the line on the steam-valve
is nearer the end of the cylinder, and the lead when the line
is nearer the center of the cylinder than the line on the valve-
chamber.
In adjusting the rod connecting the cut-off or tripping
cam with the governor, the governor must be at rest, and
the wrist-plate at one extreme of its throw or travel.
First adjust the rod connecting with the cut-off cam on
the opposite steam-valve so that there will be j$ inch clear-
ance between the cam and the steel on the tail of the hook.
Throw the wrist-plate to the other extreme of its travel and
adjust the cam for the other steam-valve in the same manner.
Now block the governor up i^ inch, which will be its
average distance when running. Hook the engine in and
turn it slowly in its running direction, and mark the distance
the cross-head travels from its extreme position of dead-
center when the cut-off cam trips the steam-valve. Continue
to turn the engine slowly past the ou,cr dead-center, and
mark the distance of the cross-head from its extreme of travel
when the steam-valve drops. If the distance is the same in
both cases, the cut-off is equal and the adjustment is correct.
If not, adjust one or the other of the . ods until this is so.
3°
THE STEAM-ENGINE INDICATOR.
The steam-engine indicator is now recognized as a highly
essential device, with which every engineer should be familiar.
The three main objects for which the indicator can be em-
ployed are:
1. To serve as a guide for setting the valves of an engine.
2. To determine the indicated power developed by an
engine.
3. To determine, in connection with a feed- water test,
showing the actual amount of steam consumed, the economy
with which an engine works.
Among the various indicators now on the market, the Ta-
bor Indicator is recognized as the standard, and has been se-
lected to illustrate this article.
All indicators h?.ve one essential plan of construction:
There is a steam-cylinder and a paper drum.
The steam-cylinder is designed to connect with the inte-
rior of the engine-cylinder and receive steam whenever the
engine receives it. A piston, which is inclosed, communi-
cates motion to a pencil arranged to move in a straight line;
the amount of movement being limited by the tensio" of a
spiral spring against which the piston acts.
1\& paper drum is a cylindrical shell mounted on its axis,
and is made to turn forward and backward by a motion de-
rived from the cross-head of the engine. A sheet of paper,
wc\cardy as it is named, is stretched upon the drum, and a
pencil is brought to bear upon it. In this manner, the
instrument traces upon the paper a line termed the indicator
diagram, which is the object sought.
Since the motion of the card is made to coincide with
that of the piston of the engine, and the height to which the
pencil rises varies according to variations in the force of the
steam, the indicator diagram presents a record of the
pressure of the steam in the engine cylinder at every point of
the stroke.
Sectional View of Standard Instrument
THE METHOD OF INDICATING A STEAM-ENGINE.
There are two things to be done in making arrangements for
indicating a steam-engine. First, the indicator must be at-
tached to the cylinder; and second^ means must be provided for
giving motion to the paper drum. To attach the indicator, a
hole is drilled at each end of the cylinder, and tapped for the
reception of a half-inch stenm-pipe(for the Tabor indicator) to
which to connect the indicator cock. In horizontal engines,
32
the barrel of the cylinder should be selected in preference to
the heads, as in the position thus secured the indicator can be
themost easily operated. Wherever attached, it is important
that the pipe should communicate freely with the steam in
the cylinder. The hole should not be located, for example,
in such a position that it is covered by the piston rings at
the end of the stroke. The pipes should be short and free
from unnecessary bends.
If a valve is used beneath the cock, it should be of the
straght-way type. It is not best to connect the two ends and
use a single indicator applied at the center. . Errors are pro-
duced by the long connections and increased number of bends
that this requires, especially at high speeds.
If but one indicator is available, it maybe used alternately,
first on one end and then on the other; should it be necessary
to place the indicator at the center, as convenience in operat-
ing generally requires in locomotive work, the errors due to
long connections may be reduced by the employment of large
pipes and easy bends. For these positions, a three-way cock,
to which the indicator cock is attached, is a useful appliance.
In drilling and tapping new holes in a cylinder, care should
be taken that the chips do not enter it, unless they can after-
ward be removed. If no better means can be employed,
steam may be admitted while the work is going on, and the
chips blown out as fast as formed.
Before attaching the indicator, the cock should be opened
to the atmosphere, and the pipes cleared of any loose material
that may have lodged in them.
INDICATOR DRIVING RIGGING.
The motion to be given the paper drum is one that coin-
cides, on a reduced scale, with the motion of the piston of the
engine. It may be obtained in a variety of ways.
The active instrument here shown, is the reducing lever,
A C, which is a strip of pine board 3 or 4 inches wide, and
about I % times as long as the stroke of the engine.
It is hung by a screw or small bolt to a wooden frame at-
tached overhead. At the lower end a connecting rod, C
D, about one-third as long as the stroke, is at one end at-
tached to the lever, and at the other end to a stud screwed
into the cross-head, or to an iron clamped to the cross-head
by one of the nuts that adjusts the gibs, or to any part of
the cross-head that may be conveniently used. The lever A
C should stand in a vertical position when the piston is in
the middle of the stroke. The connecting rod, C D, when
33
at that point, should be about as far below a horizontal posi*
tion as it is above it at either end of the stroke. The cords
which drive the paper drums may be attached to a screw in-
serted in the lever near the point of suspension; but a better
plan is to provide a segment, A B, the center of which coin-
cides with the point of suspension, and allow the cords t«*
pass around the circular edge. The distance from edge to
center should bear the same proportion to the length of the
reducing lever as the desired length of diagram bears to the
length of the stroke. On an engine having a length of 48
inches the lever should be 72 inches, and the connecting rod
16 inches in length, in which case, to obtain a diagram 4
inches long, the radius of the segment should be 6 inches.
It is immaterial what the actual length of the diagram is, but
4 indies is a length that is usually satisfactory. It maybe
reduced to advantage to 3 inches at very high speeds.
34
The cords should leave segment in a line parallel with,
the axis of the cylinder. The pulleys over which they pass
should incline from a vertical plane and point to the incU •
cators wherever they may be placed.
If the indicators and reducing lever can be placed so as to
be in line with each other, the pulleys may be dispensed
with, and the cords carried directly from the segment to the
instrument, a longer arc being provided for this purpose.
The carrier pulley on each indicator should be adjusted so as
to point in the direction ir. which the cord is received.
THE ESSENTIAL 'MATURES OF THE INDICATOR DIAGRAM.
The shar^ fj( the figure traced upon the indicator card
depends altogether upon the manner in which the steam
f T,
_AJ
F.? *?l
pressure acts in the cylinder. If the steam be admitted af the
beginning, and exhausted at the end, of the stroke, and ad-
mission continue from one end to the other, the shape of the
diagram is nearly rectangular. If the admission continue
through only a part of the stroke, the diagram assumes a shape
similar to that of Fig. No. I. These two representative
forms have, in matters of detail, numberless modifications.
Fig. No. I has been taken to illustrate the essential features
of the indicator diagram, because it exhibits clearly all the
operations affected by pressure that commonly take place in
the steam engine jylinder.
This diagram shows that the admission of steam commences
at A and ends at D; the cut-oif commences at C and becomes
complete at D; expansion occurs from D to E; the release or
35
exhaust begins at E and continues to the point H ; the com-
pression of the exhaust steam commences at G and ends at the
admission point, A.
The line A B is called the admission line ; B C, the steam
lint; D E, the expansion line; F G, the exhaust or back
pressure line (or, in the case of condensing engines, the
vacuum line); H A, the compression line; and J, I, the
atmospheric line. The curve which joins two adjacent lines,
represents the action of the steam when one operation
changes to another and cannot properly be classed with either
line.
The point of cut-off, D, lies at the end of admission; the
point of release, E, at the beginning of the exhaust, the point
of compression, H, at the end of the exhaust. The propor-
tion of the whole length of the diagram borne by the distance
of the point D from the admission end, represents the pro*
portion of the stroke completed at the point of cut-off; so
also in the case of the point of release, and in that of com-
pression for the uncompleted portion of the stroke. The
pressures at the points of cut-off, release and compression are
the heights of these various points above the atmospheric line
measured on the scale of the spring.
THE USES TO WHICH THE STEAM-ENGINE INDICATOR MAY
BE APPLIED.
There are three main objects for the determination of
which the indicator diagram may be employed :
First. To serve as a guide in setting the valves of an
engine.
Second. To determine the indicated power developed by
an engine.
Third. To determine, in connection with a feed-water
test showing the actual amount of steam consumed, the econ-
omy with which an engine works.
First. Figure No. I,, shows the general features of a
well-formed indicator diagram, the attainment of which
should be the aim in setting the valves of an engine. The
admission of steam is prompt, making the admission line per-
pendicular to the atmospheric Hne; the initial pressure is
fully maintained up to the po;:<t where the steam begins to be
cut off; the somewhat early release secures a free exhaust
and a uniformly low back pressure, and the exhaust valve
closes before the return stroke is completed, providing for
compression. These are the first requirements to be met in
producing an economical engine.
36
Derangement of the valve-gearing is revealed in the dia-
gram By tardy admission or release, by low initial pressure or
high back pressure, or by absence of compression, either one
of which causes an increased consumption of steam for per-
forming the same amount of work.
The angular position of the eccentric controls all the
movements of the valves, but improper lengths of the con-
necting rods which operate them, or improper proportions of
lap and lead, are liable to produce some of the faults we
mention, as w-ill also a wrong position of the eccentric.
In regulating the exhaust of an engine, the desirability of
employing compression should not be overlooked. In the
first place, it serves to overcome the momentum of the recip-
rocating parts and to reduce the strain upon the connections
caused by the sudden application of the pressure at admis-
sion. In the second place, compression is desirable on the
ground of economy in the consumption of steam. It fills the
wasteful clearance spaces of the cylinder with exhaust steam,
otherwise requiring the expenditure of live steam from the
boiler. Compression produces a loss by the increased back
pressure which it occasions, but the loss is more than cov-
ered by the gain resulting from the reduction of clearance
waste. iHypothetically, the greater the amount of exhaust
that is utilized by compression the less the consumption of
steam. Practically, it is not advisable to compress above the
boiler pressure. In a non-condensing automatic cut-off engine
with 3 per cent, clearance working at 75 Ibs. boiler pressure,
cut off at one-fifth of the stroke, and exhausting under a min-
imum back pressure, the gain produced by compressing up to
boiler pressure over working under the same conditions with-
out compression, should be not less than 6 per cent. Tn a
condensing engine, working under similar condition >, the
gain should be larger. It should be larger, also, with an
earlier cut-off.
The valves being in proper adjustment, the indicator dia-
gram shows whether the pipe and passages for the admission
and exhaust of the steam are of sufficient size. In automatic
cut-off engines the admission line should be parallel with the
atmospheric line, and the initial pressure should not be more
than 3 Ibs. less than the boiler pressure. The back
pressure should not in any engine exceed i Ib. when the ex-
haust proceeds directly to the atmosphere. Much can often
be learned by applying the indicator to the steam and exhaust
pipes, using the same mechanism for driving the paper drum
as that used when the indicator is operated at the cylinder.
37
Before making adjustments it pan engines that have been,
long in usey the operator should ascertain whether a valve
which should travel in a different place has worn to a shoul-
der upon its seat. If changed under such circumstances^
loss from leakage may follow ', sufficient in amount to neutral-
ize the saving that might otherwise result. This is a matter
of much importance.
Second. "The indicator is useful in determining the amount
of power developed by an engine. The diagram reveals the
force of the steam at every point of the stroke. The power
is computed from the average amount of this force, which is
independent either of the adjustment of the valves, the
form of the diagram or of any condition upon which economy
depends. The diagram gives what is termed the indicate?
power of an engine, which is the power exerted by the steam.
The indicated power consists of the net power delivered and,
in addition, that consumed in propelling the engine itself,
[jln this connection the indicator proves invaluable for
measuring the amount of power transmitted to a machine or
set of machines, which the engine is employed to drive.
The process of measuring power thus used consists in
indicating the engine, first with the machinery in operation,
and then v \ tJbe driving- belt ow shaft thrown off. The
difference in the amount 01 power developed in the two
cases is the desired result. Tenants, and those who let
power, frequently employ the indicator for this purpose.
Third A. third use for the indicator is in connection with
a feed-ivatei \*5t, in determining the number of pounds of
steam consumed by ?.n engine per indicated horse-power per
hou/.
This quantity forms a treasure of the performance of an
engine, and when compared with the performance of the best
of its class, shows the economy with which the engine works.
The amount of steam consumed is usually found by weigh-
ing the feed-water before it is supplied to the boiler, the
steam being employed during the tost for no other purpose
than driving the engine. This requires the erection of a
weighing apparatus, the most satisfactory form of which con-
sists of two tanks and platform scales. One tank is placed
on the scales, and -these are elevated above the second tank,
which is of comparatively large size. The water is first
drawn into and weighed in the first tank. It is then emptied
into the second tank, which serves as a reservoir, and from
this it is pumped into the boiler.
A simpler plan may be resorted to, w'hich gives approxi-
mate results. The feed-water is brought to a high point on
the glass water-gauge and then shut off, and a test made by
observing the rate at which the water boils away. A fall of
six inches may be allowed in nearly every case without again
feeding. The heights at the beginning and the end of the
test being carefully observed, the amount of water evapo-
rated and supplied to the engine is computed from the cubical
contents that it occupied in the boilers. A test made in this
manner can be repeated a number of times, and the results
averaged to insure greater accuracy.
Feed-water tests, made by measuring the water fed to the
boiler, are of no value unless leakage of water from the boiler,
if any exist, is allowed for. Attention should always be
given to this point and the rate of leakage determined by
observing the fall of water in the gauge, when no steam is
being drawn from the boiler, a constant pressure being main-
tained.
A portion of the feed-water consumption of an engine may
be found without the aid of a feed-water test, by computation
from the diagram. Were it not for the losses produced by
leakage and cylinder condensation, to which engines are sub-
ject the whole amount of feed- water consumed i merit be de-
termined in this manner. Leakage of steam often occurs
and cylinder condensation is inevitable, while the extent
to which these losses act is not revealed by any marked effect
produced upon the lines of the diagram. The measurement
of the consumption of steam by diagram, therefore, cannot
be taken to show actual performance without allowing a
margin for these losses. Much value, however, often at-
taches to these computations.
Besides showing the economy of an engine compared with
the best of its class, the indicator, by means of the feed -water
test, reveals the extent of the losses produced by leakage and
cylinder condensation. These losses are represented by that
part of the feed-water consumption which remains after de-
ducting the steam computed from the diagram, or steam ac-
counted for by the indicator, as it is termed. One of these
losses, condensation, is nearly constant for different engines
working under similar conditions, and an allowance may be
made for its amount. The other, leakage, is variable in dif-
ferent cases, depending upon the condition of the wearing
surfaces of valves, piston and cylinder. The fact of the pres-
ence of the latter may be detected by a trial under boiler
pressure with engine at rest, the leakage being revealed by
escape at the indicator cock or exhaust pipe. The amount of
39
this leakage may be found by computing that part of the loss
not covered by condensation. In other words, in the case of
leaking engines, when the indicator and feed-water test show
.that there is more loss than is produced in good practice by
condensation, the excess represents the probable amount of
loss by leakage. A valuable use for the indicator is thus
found in connection with the feed-water test. To make it
available in practice, Tables Nos. I, 2. and 3 are appended,
showing the percentages of loss that, occui from cylinder
condensation. The quantities in Table No. I apply to that
type of simple engine commonly used, that is, to unjacketed
engines having cylinders exceeding twenty inches in diameter;
the quantities in Table No. 2 apply to compound engines of
the best class having steam jacketed cylinders; and the quan-
tities in Table No. 3 apply to triple expansion engines of the
best class, also having steam jacketed cylinders, all supplied
with dry but not superheated steam.
TABLE NO. I.
Percentage of loss by cylinder condensation taken at cut-off
in simple engines.
Percentage of Feed-
Percentage of Feed-
Percentage of stroke
completed at cut-off.
water consumption
accounted for by the
water consumption
due to cylinder con-
indicator diagram.
densation.
5
P
42
IO
66
34
15
7i
29
20
74
26
3°
78
22
40
82
18
50
86
14
TABLE NO. 2.
Percentage of loss by cylinder condensation taken at cut-off
in the H. P. cylinder in compound engines.
Percentage of Feed-
Percentage of Feed-
Percentage of stroke
completed at cut-oft".
water consumption
accounted for hy the
water consumption
due to cylinder con-
indicator diagram.
densation.
10
74
26
'5
76
24
20
78
22
3°
82
18
40
85
15
50
88
12
40
MANNER OF TAKING DIAGRAMS
To take a diagram, a blank card is stretched smoothly upon
the paper drum, the ends being held by the spring clips.
The driving cord is attached and so adjusted that the motion
of the drum' is central. The cock is opened to admit steam
to the indicator till the parts have become heated, which
will be after a half-dozen revolutions. On being shut off,
the pencil or marking point is brought into contact with the
paper, the stop screw is adjusted, and a fine clear line traced
upon the card. This is the atmospheric line. The cock is
then opened, and after two or three revolutions the pencil is
again applied and the diagram taken. If it is desired to as-
certain the condition of the valve adjustment, the pencil
needs to be applied only while the engine is making one rev-
olution. But to determine power, it should be applied a
longer time, so as to obtain a number of diagrams superposed
on the same card. The fluctuations in the admission of
steam, produced by governors which do not regulate closely,
are so common, that this course should always be followed to
obtain average results. The diagram having been traced,
and the cock shut, the pencil should be applied lightly to the
paper to see that the position of the atmospheric line re-
mains the same. If a new line is traced, it is evidence of
error or derangement, and the operations should be re-
peated on a new card.
It is well to mark upon every card the date, time of day,
and end of the cylinder from which it was taken. In ad-
justing the valves, the boiler pressure should be observed,
and the changes that are made before taking a diagram .noted
on the card for reference. If a series of diagrams is being
obtained for power, they should be numbered in order, and
the number of revolutions per minute noted, either upon
every card, or, if the speed is nearly constant, upon every
other one.
If tests are to be made for power used by machines or
tenants, a number of diagrams should be obtained under each
condition and the results averaged. It is well, in these cases,
to mark each card of a set by some letter of the alphabet,
and on the first of the set specify the machines in operation
at the time.
SPECIAL INSTRUCTIONS.
When accurate work is desired, too much care cannot be
exercised in indicating an engine, and a further consideration
41
of some of the points to be observed will aid the engineer
in realizing their importance.
Short steam connections from the cylinder to the indicator
are desirable in all cases, and absolutely necessary with high
speed engines. Avoid all turns, if possible.
Lubrication of the indicator piston. — The best cylinder
oil only should be used for this purpose. The piston should
be removed, and the cylinder and piston cleaned and oiled
every half-dozen diagrams. The oil contained in the steam
is not sufficient in any case to lubricate this piston. Alack
of lubrication will make a jumping acti on in the movement
of the pencil, showing a series of steps, not waves, on the
diagram.
Spring to be used. — On slow speed engines the lightest
spring that will accommodate the pressure is best, but in
high speed engines a heavier spring is necessary for the same
pressure, in order to restrict the movement of the pencil bar
and connections, and prevent their inertia from distorting the
diagram. A waving line is the result of too great a move-
ment of these parts.
The tension of the spring in paper drum should in all
cases be just sufficient to keep the cord tight; but this means
that a greater tension must be used with high than with low
speeds, to prevent the inertia of the drum over-winding itself
and distorting the diagram; breakage of the cord also fre-
quently results from this cause.
Keeping the cord leading from engine under tension. — ,
This is of no importance with slow running engines,
but when indicating high speed engines it is desirable
that this cord should always be kept taut, whether the
paper drum is running or not. A good plan is to fasten
one end of a rubber band to the driving cord four or five
inches from the end and attach the other end of the band to
the indicator just below the carrier pulley, so that it always
keeps a tension on the driving cord; then make a loop in the
end of this cord for hooking on the indicator, and the loose
end admits of readily connecting and disconnecting without
allowing the driving cord to become slack for an instant.
Length of the diagrams. — With slow speeds a length of 4
in. to 4^ in. will show well proportioned diagrams, but as
the speeds increase the diagrams must be shortened to avoid
the effects of the inertia of the paper drum; and at very high
speeds an instrument with the small paper drum should be
used. Diagrams at very high speeds should not exceed 2 hif
in length, and frequently i^£ in. will give better results.
42
The pressure of the p'eri'cil on the paper should be just
sufficient to make a legible mark, and no more; a greater
pressure only creates friction, and consequent^ inaccuracy in
the diagram.
Water in the indicator will make a curious but not a use-
ful diagram, and therefore care should be exercised that the
indicator is thoroughly heated up before a diagram is taken.
Also, if much water is entrained in the steam, it will be nec-
essary to leave the cylinder cocks slightly open while taking
diagrams, as otherwise a distorted diagram is almost a cer-
tainty.
When taking diagrams from steam-engines, the height of
the barometer or pressure of the atmosphere should always
be carefully noted. This is necessary when the economy of
the engines are to be considered, and it is desirable in all
cases to know how much the exhaust pressure is above zero.
Even at the sea level the pressure is constantly changing,
and there are many engines working at places far above the
sea level where the atmospheric pressure is always less, and
in some cases very much less, than 14.7 Ibs. per square inch,
or 29.9 in. of murcury. Care should therefore be exercised
in this respect, as there is a tendency among engineers to
ignore this fact.
All gauges in ordinary use indicate pressures above the
atmosphere; if pressure gauges, or if vacuum gauges the
amount below atmospheric pressure; but neither kind show
the pressure above zero, or total pressure, and to arrive at
this, the pressure of the atmosphere must be added to the gauge
pressure in the first case, or the amount of vacuum sub-
tracted from the atmospheric pressure in the second.
THE METHOD OF COMPUTING THE HORSE-POWER OF AN
ENGINE FROM THE INDICTOR DIAGRAM.
The work done by the steam in the cylinder of an engine
is measured by the product of the force exerted on the
piston, into the distance through which the piston moves,
and is usually expressed by the term foot-pounds. If, for
example, a force of 33 Ibs. per square inch on a piston having
an area of 100 square inches is employed to drive the piston
100 times over a stroke of 4 feet, the work done by the steam
amounts to 1,320,000 ft. Ibs. The amount of horse-power
which the steam develops is the foot-pounds of work done in
a minute divided by 33,000. In the example given, the
horse-power developed when 100 strokes are made per
minute i.s 1,320,000 divided by 33,000 or 40 H. P.
The force exerted upon the piston is given by tlieindicaic-
diagram, but as it varies in amount at different points of the
stroke, it is necessary to determine the equivalent force
which, acting constantly, would produce the same result.
This is done by computing from the diagram what is termed
the mean effective pressure. The product of the mean
effective pressure, expressed in pounds per square inch; the
area of the cylinder, expressed in square inches; the length of
the stroke, expressed in feet; and the number of strokes per
minute, which is twice the number of revolutions per minute,
gives the number of foot-pounds of work performed per
-rrrf
H
X.
m
minute. This result, divided by 33,000 gives the amount of
horse-power developed.
To compute from the diagram the mean effective pressure,
two lines are drawn perpendicular to the atmospheric line,
one at each end of the diagram, and the intermediate
space divided into 10 equal parts, with a perpen-
dicular at each point of division. A ready method
of performing the division is to lay upon the diagram
a scale of 10 equal parts, the total length of which
is a small amount in excess of the length of the
diagram. It is so placed in a diagonal position that the
extreme points on the scale lie upon the two outside perpen-
diculars. The desired points may then be dotted with a
sharp pencil opposite the intermediate divisions on the
Scale. The points where the lines of division cross the
44
diagram should be dotted; and in locating these points they
should be so placed that the area of the figure inclosed by
straight lines joining them is exactly equal to the area in-
closed by the curved line of the diagram. The proper loca-
tions can be readily determined by the eye.
Figure No. 2 shows the extreme perpendiculars A B and
C D, the intermediate lines of cliv sion, the points of inter-
section, and those points which require special location, as,
for_example, the one at E, which is so placed that the area
inclosed by the straight lines, E E and E G, is equal to that
inclosed by the diagram from F to G.
The determination of the mean effective pressure consists
now of finding the average length of the various perpendicu-
lar lines included between the points of intersection, meas-
ured on the scale of the spring. This may be done by meas-
uring each line with the scale and averaging the results. 'A
better and quicker method is to employ a strip of paper, one
of the cards upon which the diagram is traced, if desired, and
mark one after another the various distances on its edge,
making thereby a mechanical addition, and requiring only a
final measurement.^ The proper course to pursue is to lay the
edge of the paper on the first line and mark off the distance,
A H, starting from the end of the paper. Transfer the edge of
the paper to the last line, and add to the first measurement the
distance, I D. Mark off from the end of the paper one-half
of the sum of these two distances, and from the middle point
continue the addition for the intermediate nine divisions.
When all have been marked measure with the scale of the
spring, from the end of the paper to the end of the last
addition, and divide the result by ten. This gives the mean
effective pressure. It is essential that one-half the sum of
the first and last distances be taken, and the sum of this
together with the intermediate nine be divided by ten. An
erroneous result is obtained by taking the sum of the whole
and dividing by eleven.
The engineer who is so fortunate as to possess the knowl-
edge necessary to operate an Indicator will find that his posi-
tion is not only more secure to him, but his employers will
be very apt to show their appreciation in a pecuniary manner.
The use of the Indicator as a detective, detecting errors,
misadjustments, waste and lost motion in an engine makes it
a most necessary adjunct to the engine-room. 'This fact is
becoming "^ore patent every day.
45
STEAM-BOILERS.
All boilers are divided into three different parts, viz., fire-
surface, water-space and steam-room. Each part or division
has a distinct and separate duty to perform. The fire-surface
includes the furnace and combustion chamber, flues and
tubes; the water-space is that part occupied by the water; and
the steam-room is the reservoir which holds and supplies the
steam necessary to run the engine.
All steam-boilers are either internally or externally tired.
Locomotive, marine and portable boilers are internally fired
because the fuel is burned in an iron furnace surrounded with
a water-jacket or water-leg. Cylinder-flue, double-deck, tub-
ulous and sectional boilers are externally fired, because the
fuel is burned in a brick furnace lined with fire-brick.
A perfect steam-boiler should be made of the best material
sanctioned by use, and should be simple in construction.
It should have a constant and thorough circulation of water
throughout the boiler, so as to maintain all parts at one tem-
perature.
It should be provided with a mud-drum to receive all im-
purities deposited from the water, and the mud-drum should
be in a place removed from the action of the fire.
It should have a combustion chamber so arranged that the
combustion of the gases commenced in the furnace may be
completed before the escape to the chimney.
All parts should be readily accessible for cleaning and
repairs.
The boiler should have ample water surface for the dis-
engagement of the steam from the water in order to prevent
foaming. It should have a large excess of strength over
any legitimate strain. It should be proportioned for the
work to be done.
It should have the very best gauges, safety-valves, fusible
plugs, and other fixtures.
A water-tube boiler should have from 10 to 12 square feet of
heating surface for one horse-power; a ttibular boiler 14 to
1 8 square feet of heating surface for one horse-power; a
flue-boiler 8 to 12 square feet of heating surface for one horse-
power ; a plain cylinder boiler should have from 6 to 10
square feet of heating surface for one horse-power; ^.locomotive
boiler should have from 12 to 16 square feet of heating surface
for one horse-power; a vertical boiler should have from 15 to
20 square feet of heating surface for one horse-power.
The following table gives an approximate list of square feet
of heating surface per H. P. in different styles of boilers; the
46
rate of combustion of coal per hour, per square foot of grate
surface, required for that rating; the relative economy, and
the rapidity of steaming:
TVI-E OF BOILER.
Sq. ft. for
one H. P.
Coal for
each sq. ft.
Relative
Economy.
Relative
rapidity of
Steaming.
Water tube ".
IO to 12
.3
I .OO
1. 00
Tubular
14 to 18
.25
.91
-5°
Flue
8 to 12
•4
•79
•25
Plain cylinder
6 to 10
.5
.69
.20
Locomotive
12 to 16
-275
.85
.55
Vertical tubular.
15 to 20
25
.80
.60
to
HORSE-POWER.
Strictly speaking there is no such thing as " horse-power "
a steam boiler; it is a measure applicable only to dynamic
effect. But, as boilers are necessary to drive steam-engines,
the same measure applied to steam-engines has come to be
universally applied to the boiler. The standard, as fixed by
Watt, was one cubic foot of water evaporated per hour from
212° for each horse-power. This was, at that time,
the requirement of the best engine in use. Since Watt's
time, however, this requirement has been reduced until
engines requiring but one-half or one-quarter a cuWc foot of
water per hour, are in daily use. However, even though
the Centennial Exposition in Philadelphia adopted as a
standard for tests of boilers 30 founds water per hour, eva-
porated at 70 pounds pressure, from 100° for each horse-
power, the general rule, in estimating horse-power of boilers
is based on its evaporating one cubic foot of water per horse-
power per hour. A cubic foot of water weighs 62^ pounds.
Estimating horse-power of boilers. — One cubic foot, or
62^ pounds, or 6.23 gallons of water evaporated per hour,
is equivalent to one horse-power. That is, a boiler that will
evaporate ten cubic feet of water, or 625 pounds of water, or
62 1/3 gallons of water per hour, is a boiler of lo horse-power.
An easy approximate rule for estimating the horse-power of
a boiler off-hand (if the boiler is a cylinder or flue boiler) is
to multiply the length of the boiler by the diameter, in feet,
and divide by 6; the quotient will be the nominal horse-
power. •£ Another rule,— Multiply the heating surface in
square yards by the fire grate surface in square feet; the
square root of the product will be the nominal horse-power.
47
In estimating the heating surface of a boiler, a vertical or
upright surface has only one-half the evaporative value of a
horizontal surface above the flame. That is, the sides of a
locomotive fire-box are only half as effective per square foot
as the flat top of the box. In flues and tubes, the effective
surface, measured on the circumference, is i% times the
diameter.
To find the fire-grate surface of fine boilers. — Square the
nominal horse-power, and divide it by the heating surface in
square yards ; the quotient will be the fire-grate surface in
square feet — or, one square foot of fire-grate surface per
nominal horse-power.
To find the hea'ing surface of a flue-boiler. — Square the
nominal horse-power and divide that by the fire-grate surface
in square feet; the quotient will be the heating surface in
square yards.
Capacity of Boiler Jlue. — One cubic yard of boiler capa-
city for each nominal horse-power. Steam room should be
about eight times the contents of the cylinder of the engine
supplied with steam by the boiler.
To find the nominal horse-power of a locomotive boiler.-* -
Square ihe area of the heating surface in square feet, and
divide by the area of the fire grate in square feet; multiply
the quotient by .0022; the product will be the nominal horse-
power.
To find the area of the heating surface of a locomotive
boiler. — Multiply the nominal horse-power by the area of
the grate in sqtiare feet; extract the cube root of the product,
and multiply the root by 21.2, the product is the area of the
heating surface in square feet.
To find the area of the fire-grate surface of a locomotive
boiler. — Square the area of the heating surface in square
feet, divide it by the number of nominal horse-power, or the
cubic feet of water evaporated per hour. The quotient
multiplied by .0022 will be the area of the fire-grate surface in
square feet.
Or, divide the area of the heating surface in square feet by
65, the quotient will be the area of the fire-grate in square
feet, nearly.
Tubular or marine boilers. — Each nominal horse-power
requires the evaporation of one cubic foot of water per hour;
12 square feet of heating surface, only three-fourths of the
whole tube-surface being taken as effective; and 30 square
inches of fire-grate per nominal horse-power. The sectional
area of the tubes to be about one-sixth of the fire-grate.
49
General rule for all classes of boilers. — Twelve square reet
of heating surface and three-fourths square foot of fire-grate
per nominal horse-power, are very good proportions.
TEMPERATURE INDICATED BY THE COLOR OF THE FIRE.
To determine the temperature of a furnace fire from the
color of the flame:
Faint red 960° F.
Bright red 1,300° F.
Cherry red 1, 600° F.
Dull orange 2,000° F.
Bright orange 2, 100° F.
White heat.. 2,400° F.
Brilliant white heat 2,700° F.
RULES FOR SAFETY-VALVES.
(See also f age 82.}
I. — To find the distance from the fulcrum at which a given
weight is to be placed on the lever, in order to balance a given
pressure in the boiler. — Multiply the steam presstire on the
whole area of the safety-valve by the distance of the center of
the valve from the center of the fulcrum. Multiply the dead
weight of the lever and the valve by half the length of the
lever, subtract this product from the first product, and divide
the remainder by the given weight, supposed to be a cast-iron
ball. ^The quotient is the required distance of the weight
from the fulcrum in inches. It is necessary, in order to find
the steam pressure on the valve, to multiply the area of the
valve-seat in inches by the pounds pressure per square inch.
Suppose that the entire pressure of steam on the valve is 24
pounds, that the center of the valve is 2 inches from the cen-
ter of the fulcrum, and that the weight of the ball is 3 pounds
— the first product is 24 X 2 = 48 ; the length of the lever is
16 inches, and the united weight of the lever and valve is
4 pounds; then the second product is (16—2) 8 X 4 = 32.
Then 48 — 32 = 16, and 1 6 ~- 3 =5^ inches, the required
distance of the center of the ball from the center of the
fulcrum.
2. To find the weight of the ball to hang onto a given
length of lever, in order that the steam may blow off at a,
g&ven pressure. — Multiply the whole pressure on the valve
by its distance from the fulcrum (center to center) ; from this
product subtract the product of the weight of the lever and
valve, multiplied by one-half of the length of the lever;
then divide the remainder by the whole length of the lever.
The quotient is the weight of the ball in pounds.
For example — The pressure in the boiler is 60 pounds per
square inch on the valve, the center of the valve is 2 inches
from the fulcrum, the weight of the valve and lever is lo
pounds, and the length of the lever is 14 inches.
Suppose the opening in the boiler to be 2 inches in diame-
ter, then 2 squared = 4 : and 4 multiplied by .7854 = 3. 1416
square inches, the area of the valve. The whole pressure on
the valve is 60 pounds 3.1416 = 188.496 pounds. The
distance of the center of the valve from the fulcrum is 2
inches, and 188.496 multiplied by 2= 376.992. From this
product, subtract the product of the weight of the valve and
lever (10 pounds) by the half-length of lever, 7 inches (total
length of lever 14 inches) or lo 7 = 70. Then 376.992 —
70 = 306. 992; and 306. 922 divided by the length of the lever,
or 14 inches, equals 21. 928 pounds, the required length of ball.
To find the pressure on the valve. — Multiply the weight of
*ke ball by the length of the lever; to this product add the
/•tf-ocruct of trie weight of the lever and valve by the half-
length of lever, and divide the sum by the distance of the
valve from the fulcrum. The quotient is the pressure on the
valve in pounds. Divide this quotient by the area of the
valve in square inches, and the quotient will give the blow-off
pressure.
Suppose the ball weighs 21.928 pounds, the length of the
lever 14 inches, the weight of the lever and valve 10 pounds,
the distance of the valve from the fulcrum 2 inches, then
(21.928 X 14 = 306.992) + 10 X 7 = 70 = 376.992; and
376.992 -:- 2 = 188.496 pounds, the whole pressure on the
valve. This pressure divided by 3. 141 6 square inches, the
area of the 2" valve =60 pounds, the pressure per square
inch on the boiler.
SAFETY VALVE CAPACITY.
A safety valve should be capable of discharging all the
steam that the boiler can make with all other outlets shut.
The United States regulations call for one-half square inch
valve area for each square foot of grates; but where the lift
will give an effective area of one-half that due to the diameter
of the valve, one-fourth square inch valve area per square
foot of grate will answer. They give the following diame-
ters:
Area of Grate, Square Feet.
Diameter of Valve, Inches.
Common Valve.
Improved Valve.
1#
2
2/8
2X
2/8
2'X
2,¥
I«
I
33X
3#
4
4X
4/8
4^
4^
4^
n
i
i
ift
1/8
j#
1/8
I#
1/8
I*
:*i#
i/s
2
2
2>£
2X
2X
2/8
2/8
^
,_
8
o. .
10
12 . .
14. . . ...
16 ,
18
20
22
24
26
28
3O
^2
34
36
CARE OF BOILERS.
1. Safety Valves. — Great care should be exercised to see
that these valves are ample in size and in working order.
(See rules for Safety Valves, page 82.} Overloading or neg-
lect frequently lead to the most disastrous results. Safety-
valves should be tried at least once a day to see if they
will act properly.
2. Pressure Gauge. — The steam-gauge should stand at
zero when the pressure is off, and it should show same press-
ure as the safety valve when the latter is blowing off. If
not, then one is wrong, and the gauge should be tested by
one known to be correct.
3. Water Level. — The first duty of an engineer before
starting is to see that the water is at the proper height. Do
not rely on glass gauges, floats or water alarms, but try the
gauge-cocks.
4. Gauge-Cocks and Water-Ganges. — Both must be kept
clean. Water-gauges should be blown out frequently, and
the glasses and passages to gauge kept clean.
5. Feed-Pumpor Injector. — ^hese should be kept in per-
52
feet order, and of ample size. No make of pump can be
expected to be continuously reliable without regular and care-
ful attention. It is always safe to have two means of feeding
the boiler. Check-valves and self-acting feed-valves should
be frequently examined and cleaned. Satisfy yourself that the
valve is acting when the feed-pump is at work.
6. Low Water. — In case of low water immediately cover
the fire with ashes (wet if possible) or any earth that may
be at hand. If nothing else is handy use fresh coal. Draw-
fires as soon as it can be done without increasing the heat.
Neither turn on the feed^ start or stop engine^ or lift safety-
valve iintil fires are out and the boiler cooled down.
7. Blister and Cracks. — These are liable to occur in the
best plate iron or steel. When first indications appears,
there must be no delay in having it examined and carefully
cared for.
8. Fusible Plugs. — When used, must be examined when
the boiler is cleaned, and carefully scraped clean on both
water and fire sides, or they are liable not to act.
9. Firing. — Charge evenly and regularly, a little at a
time Moderately thick fires are most economical, but thin
firing must be used when draught is poor. Take care to
keep the grates evenly covered, and allow no air-holes in the
fire. Be especially careful to lay the coal along the sides
and in the corners. All lumps should be broken into the
size of a man's fist. With bituminous coal, a " coking fire"
(that is, firing in front, and then shoving the coal back when
it is coked), gives the best result. Do not " clean " fires
oftener than necessary. The cleaning of the fire is best done,
in ordinary working, by a " rake," or other tool, working on
the under side of the grate, and not by a " slice-bar," driven
into the mass of fuel above the grates.
10. Cleaning. — All heating surfaces must oe kept clean,
outside and in, or there will be serious waste of fuel. The
frequency of cleaning will depend on the nature of the fuel
and water. As a rule never allow over one-sixteenth inch
scales or soot to collect on surfaces between cleanings. Hand
holes should be frequently removed and surfaces examined,
particularly in case of a new boiler, until proper intervals
between cleanings have been established by experience.
Examine mud-drums and remove sediment therefrom.
1 1. Hot Water Feed. — Cold water should never be fed into
a boiler if it can be avoided, but when necessary, it should
be caused to mix with the heated water before coding in con-
tact with any portion of the boiler.
53
12. Foaming. — When foaming occurs in a boiler, check-
ing the outflow of the steam will usually stop it. If caused
by dirty water, blowing down and pumping up will generally
cure it. In cases of violent foaming, check the draught and
cover the fires.
13. Air Leaks. — Be sure that all openings for admission
of air to boiler or flue, except through the fire, be carefully
stopped. This is often an unsuspected cause of serious waste.
14. Blowing Off. — If feed-water is muddy or salt, blow off
a portion often, according to the condition of the water.
Empty the boiler every week or two, and fill up fresh.
When surface blow-cocks are used, they should be often
opened for a few minutes at a time. Make sure no water is
escaping from the blow-off cock when it is supposed to be
closed. Blow-off cocks and check-valves should be examined
every time the boiler is cleaned.
15. Leaks. — Repair leaks as soon as possible after dis-
covered.
1 6. Emptying Boiler. — Never empty the boiler while the
brick- work is hot.
17. Rapid Firing. — Don't indulge in rapid firing. Steam
should be raised slowly from a cold boiler.
18. Standing Unused. — If a boiler is not required for
some time, empty and dry it thoroughly. If this is imprac-
tical, fill it quite full of water, and put in a quantity of
common washing soda.
19. General Cleanliness. — All things about the boiler-
room should be kept clean and in good order. Negligence
tends to waste and decay.
INJECTORS.
In setting up injectors, be careful that all the supply-pipes,
steam, water or delivery, have the same diameter (internal
diameter) as the hole, nipple, branch, plug, tee, or reducer
to which they are attached, and that they are as smooth,
direct and straight as possible.
Place a strainer over the end of the supply pipe to keep
out chips, dirt, etc., but be careful that the meshes or holes
of the strainer will equal in area the area of the supply-pipe.
In piping for steam for the injector, take steam from the
highest part of the boiler so as to get dry steam. All pipes
should be air and water tight, otherwise the injector will
kick back, take air and sputter. (?
In case the water is not to be lifted, but is fed with a head
54
from a tank or hydrant, place a stop-cock on the pipe to
keep the boiler from being flooded.
A stop-valve should also be placed in the steam-pi'oe, be-
tween the steam-room and the boiler and injector, anj a
check-valve between the \\arer-space and injector.
PUMPS FOR SUPPLYING BOILERS.
N"ver use smaller diameters of pipes than are called for in
tne ta-oles furnished by the manufacturers of the pump, as all
makers ot pumi s kn >w the capacity and work to be done by
their pumps and their calculations are correct; however,
when long pipes are used it is necessary to increase the diam-
eter to allow for increased friction. Observe this suggestion
especially in regard to suction-pipes. Use as few elbows,
T's, and valves as possible, and run every pipe in as direct a
line as practicable; use full, round bends when convenient;
use Y's instead of T's when possible. Bends, returns, T's
and elbows increase friction more rapidly than length of pipe.
"are should be taken, against leaks in the suction-pipe, as
very small leak destroys the effectiveness of the suction of a
, \mp.
See to it that a full head of water is constantly furnished
i » pump. To prevent the pump from freezing in cold
M ither, care should be taken to open the drip-plugs and
C( ks which are provided for the purpose of draining the
p\ ip.
vlrater at a high temperature cannot be raised any consid-
erable distance by suction. For pumping very hot water,
place the supply high enough so that the water will gravitate
to the pump.
A large suction-chamber placed on the suction-pipe im-
mediately by the pump is very advantageous, and for pumps
running at high speed it is a necessity. Keep the -stuffing-
boxes nicely packed. Ordinary speed to run a pump is not
over loo feet piston travel per minute. For continuous
boiler-feeding service about half that speed is recommended.
Take as good care of your pump as you do of your engine.
SOME USEFUL INFORMATION ABOUT WATER.
Doubling the diameter of a pipe increases its capacity/02^
times. Friction of liquids increases as the square of velocity.
To find the pressure in square inches of a column of water.
— Multiply the height of the column in feet by .434, approxi-
mately, every foot elevation is equal to % pound pressure
per square inch ; this allows for ordinary friction.
55
FRICTION OF WATER IN PIPES.
tfr
Friction-loss in Pounds Pressure per square inch, for each 100 feet
of length in different size clean Iron Pipes discharging given quanti-
ties of water per minute.
N
P
5
10
15
ao
25
30
35
40
45
5°
75
xoo
"5
150
175
200
250
300
350
400
45°
500
750
1OOO
1250
1500
SIZES OF PIPES — INSIDE DIAMETER.
K In-
i In.
xtfhi.
*ln.
2 In
afcln.
3 In.
4 In.
6 In.
8 In.
3-3
13.0
28.7
50 4
78.0
o 84
3 -16
6.98
12 3
19.0
o 31
1.05
2 38
4.07
6.40
0 12
0.47
o-97
1.66
2.62
0.12
0.42
48 o
16 i
6 ?2
I 60
8.15
0.81
4.89
-> H?
28.1
9.46
3-85
19.66
28 06
II. 2
15-2
25.0
30.8
1.89
2.66
3-65
4-73
6.01
7 43
0.26
o-37
0.50
0.65
0.81
0.96
2.21
3-88
0.07
0.12
0.16
0.20
0.25
0-53
0.94
1.46
2.09
The mean pressure of the atmosphere is usually estimated
at 14.7 pounds per square inch, so that with a perfect vacu-
um, it will sustain a column of mercury 29. 9 inches, or a col-
umn of water 33.9 feet high.
To find the diameter of a pump cylinder to move a given
quantity of water per minute (100 feet of piston travel being
the standard of speed), divide the number of gallons by 4,
then extract the square root, and the product will be the
diameter in inches of the pump cylinder
To find the quantity of water elevated in one minute, run-
ning at 100 feet of piston speed per minute, square the diam-
eter of the water-cylinder in inches and multiply by 4. Ex*
ample: Capacity of a 5 -inch cylinder is desired. The square
of the diameter (5 inches) is 25, which, multiplied by 4,
gives 100, the number of gallons per minute, nearly.
56
To find the horse-power necessary to elevate water to a
given height : multiply the total weight of the water in
pounds, by the height in feet, and divide the product by 33,.
ooo. (An allowance of 25 per cent, should be added for
water friction, and a further allowance of 25 per cent, for
loss in steam-cylinder. )
The area of the steam piston in square inches, multiplied by
the steam pressure, gives the total amount of pressure that
can be exerted. The area of the water piston, multiplied by
the pressure of water per square inch, gives the resistance.
A margin must be made between the power and resistance to
move the pistons at the required speed — say from 20 to 40 per
cent. , according to speed and other conditions.
To find the capacity of a cylinder in gallons. — Multiplying
the area in inches by the length of stroke in inches, will give the
total number of cubic inches; divide this amount by 231
(which is the cubical contents of a United States gallon in
inches), and the quotient is the capacity in gallons.
To find the quantity of water that will be discharged
through an opening or pipe in the sides or bottom of 'a pipe,
tank, barrel or vessel. — Multiply the area of orifice or
hole in square inches by the number corresponding to height
»f surface above orifice, as per table. The product will be
the cubic feet discharged per minute.
Height of
surface above
Multi-
Height of
surface above
Multi-
Height of
surface ab»ve
Multi-
Orifice.
plier.
Orifice.
plier.
Orifice.
plier.
Feet.
Feet.
Feet.
I
2-25
18
9-5
40
14.2
Z
I
8
3-2
4-5
5-44
6.4
20
22
9
10.
10.5
n.
"•5
45
g
70
'I'*
1 6.
17.4
18.8
10
7-i
28
12.
80
20. i
12
7-8
30
12.3
90
21.3
14
8.4
32
12.7
100
2*.$
16
9-
35
13-3
To find the size of hole necessary to discharge a given quan*
tity of water under a given head. — Divide the cubic feet of
water discharged by the number corresponding to height, as
per table. The quotient will be the area of orifice required
in square inches.
57
i'a&ifsB'ig^ii^J
Hi
4* tO O 00*^ C^t-n Ui 4^ 4*. OJ C> j tO tO to »H M
s-fft'g
» 5
4> 4^ ON to to to to O O *^J **>J **-! ^s\ 4> 4^ OJ Oj
rr ?r
• n
ON >^ <~r\ to to N< HH
v 0
O*-J4^ CNO4^ O OO CsOJ OJ to >-i O O O O
H
SP
c|
iH|i|^^p^|
C/O t*
If
r
%
^^^
^^ ^ ^^^xx
, w
3 HgX
MS w\ M\-^X4^S^\^X •^\'^\^\ O^s. O^\.
O OO 0s. '--ri Or 4^ 4^ ^J OJ to tO tO "~< *^ "^
wf
« a
** ^X ^
III
XXXXXXXXXXXXXXXXX
:rc "*
rs -, V)
v^^tooovovooas^^^oo^ ^^^
r»
To find the height necessary to discharge a given quantity
through a given orifice. — Divide the cubic feet of water dis-
charged by the area of orifice in square inches. The quotient
will be the number corresponding to height, as per table.
The above rules represent the actual quantities that will be
delivered through a hole cut in the plate; if a short pipe be
attached the quantity will be increased, the greatest delivery
with a straight pipe being attained with a length equal to four
times the diameter of the hole. If a taper pipe be attached
the delivery will be still greater, being 1*4, times the delivery
through the plain orifice.
STEAM FOR HEATING.
In estimating for steam-heating, allow one square foot of
boiler surface for each ten square feet of radiating surface.
Small boilers should be larger proportionately than large
boilers.
Each horse-power of boiler will supply from 250 to 350 feet
of I inch pipe, or 80 to 120 square feet of radiating surface.
Under ordinary circumstances, one horse-power will heat
about as follows:
Brick buildings in blocks i5>ooo to 20,000 cubic feet.
Brick stores in blocks 10,000 to 1 5,000 * * "
Brick dwellings, exposed all sides 10,000 to 15,000 " *{
Brick mills, shops, etc 7,000 to 10,000 " "
Wooden buildings, exposed 7,000 to 10,000 '* **
Foundries and wooden shops. .. .6,000 to 10,000 " "
It is, of course, but good workmanship to make all the
joints steam and water tight, as the slightest leak in a steam-
heating system is apt to do considerable damage to furniture,
curtains, carpets, etc., if the steam is intended to heat a dwell-
ing. Red or white lead is all right as material to make up
joints, but graphite is much better (see page 141). For gas-
kets there is nothing better than asbestos, and this material
is now manufactured into gasket rings cut true to size, mak-
ing asbestos gaskets not only the best, but furnished in a
convenient form which will be highly appreciated by the
steam-fitter.
The quality of rubber sheets sold by dealers for gaskets, is
sometimes of the poorest order, and rubber in any form, vul-
canized or otherwise, is poor stuff to put in contact with
steam. Gaskets made of thin lead are good, and first class
packing can be made of candle wicking and ordinary resin
soap, but asbestos is the best.
59
THE WESTINGHOUSE AUTOMATIC BRAKE.
The Westlhghouse Automatic Brake consists of the follow-
ing essential parts :
I st. The steam engine and pump, which produce the com-
pressed air, the supply of steam being regulated by the pump-
governor.
2d. The main reservoir, in which the compressed air is
stored.
3d. The engineer* s brake-valve, which regulates the flow
of air from the main reservoir into the brake-pipe for releas-
ing the brakes, and from the brake-pipe to the atmosphere for
applying the brakes.
4th. The equalizing-valve ', which is connected to a small
reservoir, and permits the escape of air from the main brake-
pipe, until the pressure in that pipe throughout the entire
train is reduced to the same pressure as that in the small
reservoir, thus preventing the release of the forward brakes
by the engineer closing the brake-valve too quickly, before
the pressure in the rear part of the pipe has had time to be-
come reduced.
5th. The main brake-pipe, which leads from the main
reservoir to the engineer's brake-valve, and thence along the
train, supplying the apparatus on each vehicle with air.
6th. The auxiliary reservoir, which takes a supply of air
from the main reservoir through the brake-pipe, and stores it
for use on its own vehicle.
7th. The brake-cylinder, .which has its piston-rod attached
to the brake-levers in such a manner that, when the piston is
forced out by air pressure, the brakes are applied.
8th. The triple valve, which connects the brake-pipe to
the auxiliary reservoir, and connects the latter to the brake-
cylinder, and is operated by a sudden variation of pressure in
the brake-pipe (i) so as to admit air from the auxiliary reser-
voir to the brake-cylinder, which applies the brakes, at the
same time cutting off the communication from the brake-pipe
to the auxiliary reservoir, or (2) to restore the supply from
the brake-pipe to the auxiliary reservoir, at the same time
letting the air in the brake-cylinder escape, which releases the
brake.
9th. The couplings, which are attached to flexible hose
and connect the brake-pipe from one vehicle to another.
The automatic action of the brake is due to the construc-
tion of the triple valve, the primary parts of which are a
piston and a slide-valve. A reduction of pressure in the brake-
pipe causes the excess of pressure in the auxiliary reservoir to
force the piston of the- triple valve down, moving the slide*
valve clown so as to allow the air in the auxiliary reservoir to
pass directly into the brake-cyl nder and apply the brakes.
When the pressure in the brake-pipe is again increased above
that in the auxiliary reservoir the piston is forced up, moving
the slide-valve to its former position, opening communication
from the brake-pipe to the auxiliary reservoir and permitting
the air in the brake-cylinder to escape, thus releasing ihe
brakes.
Thus it will be seen that any reduction of pressure in the
brake-pipe applies the brakes, which is the essential feature
of the automatic brake. If the engineer wishes to apply
the brakes he moves the handle of the engineer's brake-
valve to the right, which first closes a valve retaining the
pressure in the main reservoir and then permits a portion
of the air in the brake-pipe to escape. To release the
brakes he turns the handle to its former position, which
allows the air in the main reservoir to flow into the brake-
pipe, restoring the pressure and releasing the brakes. A
valve called the conductor's valve is placed in each car,
with a cord running the length of the car, and any of the
trainmen, by pulling this cord can open the valve, which
allows the air to escape from the brake-pipe. In applying
the brake in this manner the valve must be held open until
the train comes to a stop. Should the train break in two
the air in the brake-pipe escapes and the brakes are ap-
plied to both sections of the train, and should a hose or
pipe burst the brakes are also automatically applied.
The gauge shows the pressure in the main reservoir and
brake-pipe when they are connected, and the pressure in the
brake-pipe alone when the main reservoir is shut off by the
movement of the engineer's brake-valve.
A stop cock is placed in each end of the brake-pipe, and is
closed before separating the couplings, thus preventing an
jpplication of the brakes when cars are uncoupled.
The diagram above the engineer's brake-valve shows the
various positions of the handle for applying the brakes with
any desired degree of force, for releasing the brakes, and the
position in which the handle is to be kept after the brakes
have been released.
Following will be found detailed views and descriptions of
detached portions of the apparatus; also a full series of in-
structions for its proper use and maintenance. Too much
importance cannot be attached to that portion of the instruc-
tions stating that engineers should use care and moderation
6i
in applying the brakes for ordina 'y stops. By applying
them at a fair distance from the station, with moderate force,
the train is stopped gently and without inconvenience to the
passengers, while if they are thrown on with the utmost force
possible, the train is jerked in a manner that is extremely
disagreeable to the passengers.
AIR PUMP-
Referring to cut, it will be seen that the steam from the
boiler enters the top cylinder between two pistons forming
the main valve. The upper piston being of greater diameter
than the lower, the tendency of the pressure is to raise the
valve, unless it is held down by the pressure of a third piston
of still greater diameter, working in a cylinder directly above
the main valve.
The pressure on this third piston is regulated by the small
slide-valve, working in the central chamber on the top head.
This valve receives its motion from a rod extending into the
hollow piston which, as shown in the drawing, has a knob at
its lower end and a shoulder just below the top head. This
valve chamber in the top head, by a suitable steam-port, is
constantly in communication with the steam space between
the two pistons of the main valve. The steam acting on the
third piston and holding the main valve down, admits steam
below the main piston; as the main piston approaches the
upper head, the reversing-valve rod and its valve are raised
until the slide-valve exhausts the steam from the space above
the third, or reversing-piston, when the main valve is raised
by the steam pressure on the greater area of its upper piston,
which movement of the main valve admits steam to the upper
end of the main cylinder.
When the main valve * .aoved up to admit steam to the
upper end of the cylinder, it opens an exhaust port at the
lower end just below the lower steam-port, which latter is
closed by the lower piston of the main valve; and when the
main piston is on its upward stroke the upper exhaust-port is
similarly opened.
The air valves of the pump are similar to those used in all
pumps. The lift of a discharge valve should not exceed one-
sixteenth of an inch, and the lift of receiving valves should
not exceed one-eighth of an inch. Care should be taken to
have the lift of the discharge valves exactly the same, other-
wise the stroke of the pump will be quicker in one direction
than in the other.
•must
TRIPLE VALVE.
The arrangement of the auxiliary reservoir, cylinder and
triple-valve, with the latter in section, are shown in cut
^-gg&s.. - .. -
The triple valve has a piston 5, working in the chamber B,
and carrying with it the slide-valve 6. Air entering from
the main pipe passes through the four-way cock 13 by ports
a, r, and the drain-cup A, and chamber B, forcing the piston
5 into its normal position as shown, thence through a small
groove past the piston into the valve-chamber above, and into
the auxiliary reservoir, while at the same time there is an open
64
communication from the brake-cylinder to the atmosphere,
through the passage d, e,f ana g. Air will continue to flow
into the auxiliary reservoir until it contains the same pressure
as the main brake-pipe.
To apply the brakes with their full force, the pressure in
the main brake-pipe is allowed to escape, whereupon the
greater pressure in the auxiliary reservoir forces the piston
down on the graduating-stem 8, and in so doing closes the
feed opening past the piston. As the piston descends, it
moves with it the slide-valve so as to permit the air to flow
directly from the auxiliary revcrvoir into the brake-cylinder,
which applies the brakes. The brakes are released by re-
admitting pressure into the main brake-pipe from the main
reservoir, which pressure, being greater than that in the
auxiliary reservoir, forces the piston back to the position
shown in the drawing, when the air in the brake-cylinder
escapes.^ To apply the brakes gently, a slight reduction is
made in the pressure in the main brake- ^pc, which moves
the piston down slowly until it is sroppecTi-y ihe graduating
stem 8 and spring 9, at this point the opening /, in the slide-
valve is opposite the port/", and allows air from the auxiliary
reservoir to feed through a hole in the side of the slide-valve
and through the opening /, into the brake-cylinder ^ When
the pressure in the auxiliary reservoir has been reduced by
expanding into the brake-cylinder, until it is the same as the
pressure in the main brake-pipe, the graduating spring pushes
the piston up far enough to close a small valve 7, which is
placed in the feed opening /, of the slide-valve. This causes
whatever pressure is in^ the brake-cylinder to be retained,
thus applying the brake with a force proportionate to
the reduction of pressure in the brake-pipe. To prevent
the application of the. brakes, from a slight reduction of
pressure caused by leakage in the brake-pipe, a semi-
circular groove is cut in the body of the car-cylinder, ^ of
an inch in width, <£, of an inch in depth, and extending so
that the piston must travel three inches before the groove is
covered by the packing leather. A small quantity of air,
such as results from a leak, passing from the triple-valve into
the car cylinder, has the effect of moving the piston slightly
forward, but not sufficiently to close the groove, which per-
mjts the air to flow out past the piston. If, however, the
brakes are applied in the usual manner, the piston will be
moved forward, notwithstanding the slight leak, and will
cover the groove. It is very important that the groove shall
be three inches long, and shall not exceed in area the dimen-
sions given above.
65
When the handle of the four- way cock 13, is turned down,
there is a direct communication from the main brake-pipe to
the brake-cylinder, the triple-valve and auxiliary reservoir
being cut out, and the apparatus can be worked as a noa-
automatic brake by admitting air into the main brake-pipe
and brake-cylinder, to apply the brakes. When from any
cause it is desirable to have the brake inoperative on anjr
particular car, the four-way cock is turned to an intermediate
position, which shuts off the brake-cylinder and reservoir,
leaving the main brake-pipe unobstructed to supply air to
the remaining vehicles.
The drain cup A collects any moisture that may a<?cumtt-
late, and is drained by unscrewing the bottom nut.
ENGINEER'S BRAKB-VALVE.
PLATE! vh
The handle I of the engineer's brake-valve terminates in a
screw with a coarse thread, which compresses a spring 4 upon
the top valve 3; this top valve fits into a slot in the handle I
66
and into a slot in the main valve 6, so that the handle and the
two valves must turn simultaneously. In the position shown
in the drawing, which is for releasing the brakes, the top valve
3 leading to the atmosphere is kept closed by the compression
of the spring 4, and the air passes freely from the main reser-
voir to the brake-pipe through the openings of the main valve
and the body of the brake-valve. After the brakes are off,
the handle is moved against the second stop, a short distance
to the right, which turns the main valve so that the main
passages to the break-pipe are closed. Air can, however,
pass through the small valve 7, and thence to the brake-pipe
through a small opening not shown in the drawing. This
small valve 7 is held down by a spring whose resistance is
equal to 20 Ibs. per square inch, hence the pressure in the
main reservoir will be 20 Ibs. greater than that in the brake-
pipe, which surplus pressure insures the certain release of the
brakes when desired. To apply the brakes the handle is
moved still further to the right, when the opening from the
small valve 7 is also closed, cutting off all communication
from the main reservoir to the brake-pipe, at the same time
the action of the screw lifts the handle and relieves the spring
4 from pressure, when the air in the brake-pipe lifts the valve
3, and escapes, until an equilibrium is established between
the air pressure and the pressure of the spring on the valve 3,
thus reducing the pressure in the brake-pipe to an extent cor-
responding to the distance which this handle is moved.
To apply the brakes suddently the handle is turned the entire
distance to the right, which relieves the spring ot all compres-
sion, allowing the valve 3 to rise, and all of the air in the
brake-pipe to escape.
After the train is stopped, the brakes are released by turn-
ing the handle to the position shown in the drawing.
The pump-governor is shown in the cut, the object of
which is to automatically cut off the supply of steam to the
pump when the air pressure in the train-pipe exceeds a cer-
tain limit, say 70 Ibs.
The operation of this governor is as follows: The wheel 8
is screwed down so as to permit the valve 10 to be unseated
by the excess of pressure on the upper side of the valve per-
mitting steam to pass through the openings A and B to the
pump. A connection is made from the train -pipe to the up-
per end of the governor, and the compressed air passes
around the stem 14 to the upper side of the diaphragm plate
18, which is held to its position by the spring 1 6, which latter
is of sufficient strength to resist a pressure of say, 70 lbs»
TO TRAM PIPS PUMP-GOVERNOR.
68
per square inch on diaphragm. As soon as the air pressure
on the diaphragm 18 exceeds this amount, it forces the dia-
phragm down, unseating the valve 13, and allowing the
steam on the upper side of the valve 10 to escape through
the exhaust 6, which causes an excess of steam pressure on
the lower side of the valve 10, forcing *.he valve against its
seat, and cutting off the supply of steam to the pump.
When the pressure in the train-pipe is diminished by ap-
plying the brakes, the diaphragm is restored to the position
shown by the action of the spring 16. The valve 13 is
seated by the spring 12, and the steam pressure passing
through the port C, accumulates on the upper side of the valve
jo, forcing it down, and opening the passage for steam to the
pump until the air pressure is again restored to the required
limit of 70 Ibs.
The use of the governor not only prevents the carrying of
an excessive air pressure by the engineers, which may result
in the sliding of the wheels, but it also causes the accumulation
of a surplus of air pressure in the main reservoir while the
brakes are applied, which insures the release of the brakes
without delay. It also limits the speed of the pump and con-
sequently the wear.
EQUALIZING VALVE.
The proper application of the brakes depends upon the
amount of air discharged from the train pipe, and the manner
in which it is discharged. The amount of air to be dis-
charged also depends upon the length of train.
As stated in the general description of the brake apparatus, '
the brakes are applied by reducing the pressure in the train
pipe, and are released by increasing the pressure. On long
trains engineers have found it very difficult to discharge the
air in such a way that they will not first cause a large reduc-
tion in the front portion of the pipe, and then an increase
tending to release the brakes on the tender and two or three
cars next ; the increase of pressure being clue to the expan-
sion of the air in the pipes of the rear portion of the train.
The equalizing valve which is shown in Plate 6 (which serves
also as a large drain cup), is a device which automatically
provides for the proper discharge of the air on all of the
vehicles, back of the tender, the engineer having to discharge
only the required amount from his brake- valve, and always a
given amount for a certain degree of application, whether the
train consists of one or fifty cars.
In the position shown, the air from the equalizing reservoir
rasses through the r>orts of the enualizint? valve as shown by
69
the arrows and into the train pipe. When the pressure in
the equalizing reservoir is reduced slightly to apply the
brakes, the piston 15 moves down carrying the valve II from
its seat and permitting the air in the train pipe to escape
through the ports d, e and g, until the pressure in the train
pipe equals that in the equalizing reservoir, when the piston
and valve 1 1 return gradually to the position shown. When
it is desired to apply the brakes quickly with full force a con-
siderable reduction is made in the pressure in the equalizing
reservoir and the piston moves down its entire distance car-
rying with it the slide valve 4 and uncovering the upper port
£•, while air is also allowed to escape through the port/" and
the lower port g, thus permitting a rapid escape of the press-
ure in the train pipe until it equals that in the reservoir,
when the valve returns to the position shown.
INSTRUCTIONS.
General. — In making up trains all couplings must be united
so that the brakes will apply throughout the entire train.
The cocks in the brake-pipe must all be opened (handles point-
ing down), except that on the rear of the last car, which must
be closed.
In detaching engines or cars the couplings must invariably
be parted by hand; the cocks in the main brake-pipes must
always be closed before separating the couplings, to prevent
application of the brakes.
If the brakes are applied when the engine is not attached
to the train or car, they can be released by opening the re-
lease cock usually put in the end of the brake-cylinder.
The adjustment of the break-gear should be such, that
when the brakes are full on, the pistons in the brake-cylinders
will not have traveled to exceed eight or nine inches. This
will allow for wear of shoes, stretching of rods, springing of
brake-beams, etc. In narrow gauge freight apparatus the
adjustment must be such that the piston will not travel more
than five or six inches.
Great care must be exercised when taking up the slack in
the brake connections to have the levers and pistons pushed
back to their proper places and the slack taken up by the
under connection, or dead levers.
The brake-cylinders must always be kept clean so that
they will readily release when the air has been discharged,
and should b6 oiled once in three months. The last date of
oiling should be marked on the cylinder with chalk.
For the automatic break the handle of the four-way cock
must be turned horizontally. If turned down it will be
70
changed to the simple air-brake; if turned midway between
these two positions, it will close communication with the
brake-cylinder and reservoir, and should be so turned when
desirable to have the brakes out of use on any particular car
on account of the breaking of rods, etc. It is very important,
in order to avoid detentions, to keep the handles of these
four- way cocks in their proper positions.
In cold weather the triple valve should be drained fre-
quently, to let out any water that may have collected. Slack
the bottom nut of the triple valve about half a turn, let the
water escape and screw it up again. The valve for the ap-
plication of the brakes from the inside of the car should be
kept tight, and must be examined by the inspectors.
Engineers must see that the steam-cylinder is kept well
lubricated; that the air-cylinder is sparingly lubricated with a
small quantity of 28° gravity West Virginia well oil; (tallow
or lard oil must not be used in the air-cylinder); that the
pump is constantly run, but never faster than is necessary
to maintain the required air pressure; and that air from 50
to 60 pounds pressure for low speed or way trains, and from
70 to 80 pounds pressure for express trains is carried.
For ordinary stops the brakes should be applied lightly by
opening the valve or cock and closing it gently when the
pressure has been reduced from 4 to 8 pounds on the gauge.
The brakes are fully applied when the pressure shown on
the gauge is reduced 20 pounds. Any further reduction is a
waste of air.
In releasing the brakes, the handle of the brake-valve
must be moved quite against the stop and be kept there for
about ten seconds, and then moved back against the inter-
mediate stop, which is the feed position, and where it must
remain while the train is running.
Engineers, upon finding that the brakes have been ap-
plied by the train men or automatically, must at .once aid in
stopping the train by turning the handle of the brake- valve
toward the right, thus preventing escape of air from the main
reservoir.
The shoes of the driving-wheel brakes should be so ad-
justed by turning the screws that the piston moves up from
3 to 4 inches when the brakes are applied.
It is important to drain the water out of the main reservoir
once a week, especially in winter time, and oftener if the
pump-rod is not kept well packed.
If cars having different air pressures be coupled together,
the brakes will apply themselves on those which have the
highest pressure. To insure the certain release of ail the
brakes in the train, and also that trains may be charged
quickly, the engineer must carry the maximum pressure in
the main reservoir before connecting to a train, and then put
the handle of his brake-valve in the release position until the
train is charged with air. If the brakes on the engine and
tender thus apply themselves by being coupled to a train not
charged, they should at once be taken off by opening the re-
lease cock from the brake-cylinders, which ought to be so
arranged as to be worked from the foot-plate.
Train- Men. — After making up or adding to a train, or
after a change of engines, the rear brakeman shall ascertain
whether the brake is connected throughout the train.
When the hose couplings are not used for connecting the
brakes between two vehicles, they must be attached to their
dummy couplings.
When there is occasion to apply the brakes from the cars,
the valve must be held open to allow the air to escape until
the train is brought to a stand-still, but this method of ap-
plication should only be used in cases of emergency.
Train-men must in all cases see that the hand-brakes are
off before starting.
Before detaching the engine or any carriages, the brakes
must be fully released on the whole train. Neglecting this
precaution, or setting the brakes by opening a valve or cock
when the engine is detached, may cause serious incon-
venience in switching.
The pipes and joints must be kept tight, and when leaks
are discovered they should be corrected, if .serious, before the
car is again used.
HOW TO APPLY AND RELEASE THE WESTING-
HOUSE AUTOMATIC BRAKE.
The brakes, as has been explained, are applied when the
pressure in the brake pipe is suddenly reduced, and released
when the pressure is restored. ^
It is of very great importance that every engineer should
bear in mind that the air pressure may sometimes reduce
slowly, owing to the steam pressure getting low, or from
the stopping of the pump, or from a leakage in some of the
pipes when one or more cars are detached for switching pur-
poses, and that in consequence it has been found absolutely
necessary to provide each cylinder with what is called a leak-
age groove, which permits a slight pressure to escape with-
out moving the piston, thus preventing the application of the
72
brakes when the pressure is slowly reduced, as would result
from any of the above causes.
This provision against the accidental application of the
brakes must be taken into consideration, or else it will some-
times happen that all of the brakes will not be applied when
such is the intention, simply because the air has been dis-
charged so slowly from the Drake-pipe that it only represents
a considerable leakage, and thus allows the air under some
cars to be wasted.
It is thus very essential to discharge enough air in the first
instance, and with sufficient rapidity, to cause all of the leak-
age grooves to be closed, which will remain closed until the
brakes have been released. In no case should the reduction
in the brake-pipe for closing the leakage grooves be less than
four or five pounds, which will move all pistons out so that
the brake-shoes will be only slightly bearing against the
wheels. After this first reduction the pressure can be re-
duced to suit the circumstances.
On a long train, if the engineer's brake-valve be opened
suddenly, and then quickly closed, the pressure in the brake-
pipe, as indicated by the gauge, will be suddenly and consid-
erably reduced on the engine, and will then be increased by
the air pressure coming from the rear of the train ; hence it
is important to always close the engineer's brake-valve slowly,
and in such a manner that the pressure as indicated by the
gauge will not be increased, or else the brakes on the engine
and tender, and sometimes on the first one or two cars will
come off when they should remain on. It is likewise very
important, while the brakes are on, to keep the engineer's
brake-valve in such a position that the brake-pipe pressure
cannot be increased by leakage from the main reservoir, for
any increase of pressure in the brake, pipe causes the brakes
to come off.
On long down grades it is important to be able to control
the speed of the train, and at the same time to maintain a good
working pressure. This is easily accomplished where the
pressure-retaining valve is not in use, by running the pump
at a good speed, so that the main reservoir will accumulate a
high pressure while the brakes are on. When, after using
the brakes some time, the pressure has been reduced to sixty
pounds, the train pipes and reservoirs should be recharged as
much as possible before the speed has increased to the maxi-
mum allowed. A greater time for recharging is obtained by
considerably reducing the speed of the train just before re-
charging and by taking advantage of variation in the grades.
73
There should not be any safety-valves or leaks in the main
reservoir, otherwise the necessary surplus pressure for
quickly recharging cannot be obtained.
To release the brakes with certainty it is important to have
a higher pressure in the main reservoir than in the main
pipe. 'If an engineer feels that some of his brakes are not
off, it is best to turn the handle of the engineer's brake-valve
just far enough to shut off the main reservoir, and then pump
up fifteen or twenty pounds extra, which will insure the re-
lease of all of the brakes; all of which can be done while the
train is in motion.
For ordinary stops great economy in the use of air is
effected by, in the first instance, letting out from eight to
twelve pounds pressure, while the train is at speed, taking
care to begin a sufficient distance from the station.
BRAKE POWER.
To obtain the best results, it is important to have the brak-
ing force proportioned to the weight of the car, or more par-
ticularly speaking, to the load carried by those wheels upon
which brakes act. After long experience it has been decided
to recommend such a proportion of brake levers that a press-
ure of fifty pounds per square inch on the brake piston will
bring a force against the brake-blocks on each pair of wheels
equal to the load carried by them; thus, owing to a great
variation of cars, it is impossible to have uniform brake
levers.
For convenience it has been found best to cut the brake
connection which joins the brakes of both trucks and to inter-
pose at this point the brake-cylinder, having with it two levers
and a tie-rod. With this arrangement it is only necessary to
get the proper portion of these cylinder levers.
The following rules will enable those whose duty it is to
attach brakes to proportion the levers, so as to carry out the
foregoing recommendation.
RULE FOR CALCULATING CAR LEVERS.
The air pressure is rated at fifty (50) pounds per square
inch on piston, when the brakes are fully applied. (50 Ibs,
per square inch gives about 4,000 Ibs. for lo-inch cylinder,
and 2,500 Ibs. for 8-inch cylinder.)
To find the leverage required. — Divide the weight of the car
resting upon the brake-wheels by the whole pressure on
piston.
To find proportipn of brake beam levers. — Divide the whole
length of lever by short end.
To find the total brake beam leverage. — Multiply propor-
tion of lever by two (2) for the Hodge system, and by four (4)
for the Stevens'.
To find proportion of cylinder lever. — Multiply the whole
length of lever by either the required leverage, or the total
brake beam leverage, and divide by the sum of both, the result
will give the length of one end of the lever.
If the required leverage is greater than the A?fo/brake beam
leverage, the long end of the lever must go next to the cylin-
der; if less, the short end must go next to the cylinder.
Dead levers must be made in the same proportion as the
other truck levers.
Example — Hodge System.
Weight of car 36,000 Ibs.
Total pressure on lo-inch piston 4,000 "
Total length brake beam lever 28 inches.
Length of short end of brake beam lever 7 "
Total length of cylinder lever 24 "
36,000-7-4,000 = 9, leverage required.
28-7- 7 = 4 X 2= 8, total brake beam leverage.
24 X 8 = 192 -7- (84-9) = 11.3, short end cylinder lever.
24 — 11.3 = 12.7, long end cylinder lever.
Example — Stevens1 System.
Total length of cylinder lever 36 inches.
36,000-7-4,000=9, leverage required.
28-7-7 = 4*4 — i6» total brake beam leverage.
36 X 9 =324 -7- (9+ 16) = 12.96, short end cylinder lever.
36 — 12.96 = 23.04, long end cylinder lever.
LOCOMOTIVES IN 1832 AND 1888.
The Baldwin Iron Works, of Philadelphia, in 1832 con-
sidered it a great feat that they had constructed an engine
which could draw thirty tons on a level, and the papers of
the day contained the following announcement:
NOTICE. — The locomotive engine built by M. W. Bald-
win, of this city, will depart daily, when the weather is fair,
with a tram of passenger cars.
tyOn rainy days horses will be attached.
Now the same works are constructing ten-wheeled con-
solidated locomotives for the Dom Pedro Railway, in Brazil,
guaranteed to draw 3,600 tons, with no reservation as to
"weather."
.
ill
|
{___} \J
•
75
COLD CHISELS.
Figures i and 2 are drawings of flat
chisels. The difference between the two is
that, as the cutting edge should be parallel
with the flats on the chisel, and as Fig. I
has the widest flat, it is easier to tell with it
when the cutting edge and the flats are parallel; therefore the
broad flat is the best guide in holding the chisel level to the
surface to be chipped. Either of these chisels is of a proper
width for wrought iron or steel, because chisels used on
these metals take all the power to drive that can be given
with a hammer of the usual proportions for heavy clipping,
which is: Weight of hammer, i# Ibs.; length of hammer-
handle, 13 in. ; the handle to be held at its end, and swinging
back about vertically over the shoulder.
If so narrow a chisel be used on cast iron or
brass with full force hammer blows, it will
break out the metal instead of cutting it, and
the break may come below the depth wanted to
chip, and leave ugly cavities.
So for these metals the chisel must be broader,
as in Fig. 3, so that the force of the blow will be spread over
a greater length of chisel edge, and the edge will not move
forward so much at each blow, therefore it will not break the
metal out.
Another advantage is that the
/ oroader the chisel the easier it is to
/ / hold its edge fair with the work
^XV surface, and make smooth chipping.
I The chisel-point must be made as
L 1 thin as possible, the thickness shown
in sketches being suitable for new
chisels. In grinding the two faces to form the chisel, be care-
ful to avoid grinding them round \ as shown in a in the mag-
nified chisel ends in Fig. 4; the proper way is to grind them
flat, as in b in the same sketch. Make the angle or edge of
these two faces as sharp or acute as you can because the
chisel will then cut easier.
For cutting brass, hold the chisel about
the angle shown in c, Fig. 5; for steel,
that at d same figure. The difference is,
that with hard metal the more acute
angle dulls too quickly.
For heavy chipping, the point may be
made flat as in Fig. I., or curved as in
76
Fig. 3,, which is the best, because the corners are relieved
from duty, and are therefore less liable
to break. The advantage of the curve
is greatest in fine chipping, because, as
seen in Fig. 6, a liner chip can be
taken without cutting with the corner,
and these corners are exposed to the
eye in keeping the chisel edge level with
the work surface.
In any case do not grind the chisel
hollow in its length, as in Fig. 7, or as shown
exaggerated in Fig. 9, because, in that case,
the corners will dig in and cause the chisel
to be beyond control; besides that, there will be
a force, that, acting on the wedge principle, will
operate to spread the corners and break them off.
Do not grind the faces wider on one side than on the other
of the chisel, as in Fig. 8, because, in that case, the flat of the
chisel will form no guide to let you know when the cutting
edge is level with the work surface. Nor must
you grind it out of square with the chisel body, as
in Fig. 10, because, in that case, the chisel will
be apt to jump sideways at each hammer-blow.
*««» A quantity of metal can be removed quicker by
using the cape chisel in Fig. n, to first cut out
grooves, spacing these grooves a little narrower
apart than the width of the flat chisel, and thus
relieving its corners. The chisel end must be shaped
as at a and ^, and not as at c in Fig.
n, so as to be able to move it side-
ways, to guide it in a straight line,
and the parallel part at c will inter-
fere with this, so that if the chisel is
started a very little out of line, it will go still
further out of line, and cannot be moved
sideways to correct the fault.
The round-nosed chisel, Fig. 12, must not be made
straight on its convex edge; it may be straight
from h to g but from g to the point, it must
be beveled, so that by altering the height of
the chisel head it is possible to alter the depth
of the cut.
The diamond point chisel in Fig. 14 and 15,
must be shaped to suit the work, because if it is not to be
used to cut out the corners of very deep holes, you can bevel
it at m, and these bring its point x, central to the body of
the steel, as shown by the dotted line q, rendering the
corner x less liable to break, which is the great trouble with
this chisel; but in cutting deep holes the bevel at m must
be omitted, and you must make the edge straight, as at r in
Fig. 15.
The side chisel obeys the same rule, so you may make it
bevel at w9 as in Fig. 16, for shallow holes, and
lean it well over in using, and make the side v w
straight along its whole length for deep holes; but
in all chisels for slots or mortises it is desirable to
have if circumstances will permit, some bevel on the
side that meets the work, so that the depth of the
cut can be regulated by moving the chisel head.
In all these chisels, the chip on the work steadies
the cutting end, and it is clear, th?t the nearer
you hold the chisel at its head the steadier yoi can hold it
and the less the liability to hit your fingers, while the chipped
surface will be smoother.
To take a chip off wrought iron, if it is a heavy chip,
stand well away from the vice, as an old. hand would do, in-
stead of close to it; if, instead, you wish to take a light chip,
you must stand nearer to the work, so that you can watch
the chisel's action and keep its depth of cut level. In both
cases you must push the chisel forward to its cut, and hold it
as steadily as possible.
It is a mistake to move it at each blow, as many do, be-
cause it cannot be so accurately maintained at the proper
height. Light and quick blows are always necessary for the
finishing cuts, whatever the kind of metal may be.
TURNING OR LATHE TOOLS FOR METALS.
Few lathe tools, except scrapers, can be used indiscrimi-
nately for cast iron, wrought iron or brass; each metal needs
its particular set of tools, differing not so much in the shape
of their cutting edges, as in the angles which they make with
the surface of the work to be turned. Thus, Figs. 17, 18,
19 are each intended to represent in profile the ordinary
roughing-down tool, but their angles are very different, the
one from the other. Fig. 17 being only suitable for wrought
iron, Fig. 18 for cast iron and Fig. 19 for brass. In all
these, everything (temper of course excepted) depend upon
the angle at which the tools are ground. The brass tool with
the flat face would not cut the iron, but would simply scratch
it; while the iron tools would hitch in the brass and tend to
" chatter," or " draw-in. " Neither would the tool ground at
an acute angle for wrought iron, cut cast metal, but would
itself become broken off at the tip, while the thicker cast iron
tool would not take clean shavings offwrought iron. Fig. 20
is a common roughing tool for cast
iron. The side view gives a proper
.angle to insure a clean cut without
breaking the top across ; in the di-
rection of the dotted line. The
angle is drawn on the supposition
that the tool is held horizontally, as indeed it should be, but
a tool that will not cut nicely in a horizontal direction will
often work by inclining it at a slight angle. Neither is the
angle at which a tool should be ground, in order to cut well
horizontally, necessarily the same. It should be about 65°
with the verical for cast iron, but may vary slightly either
way.
In fact, not one workman in ten could say what angle he
grinds his tools to ; he simply judges the proper angle by his
eye. The angle which the front of the tool makes with the
work may vary somewhat more than the upper face, depend-
ing upon the diameter of the work to be turned, but should
Dot slope more than 4° or 5° from the vertical for cast iron
(Fig. 1 8). If it becomes excessive the tool is weak and soon
breaks off.
•
i These details may seem trivial, but they are really of the
utmost importance. These sketches are taken from tools in.
79
actual use and doing their work well. Fig 21 shows a round
nose, Fig. 22 a parting tool, Fig. 23 a knife-tool for finishing
edges and faces of flanges, and ends and sides of work, either
right or left-handed (Fig. 24). The end views of these tools
show the upper and clearance angles, which are about the
same as in Fig. 1 8, but may vary somewhat according to the
work required.
Figs. 25 are boring- tools for hollow cylinders, tools capa-
CD
ble of much modification, their cutting edges not only taking
the forms of all other tools, but each form also being often
right and left-handed. In reference to the more usual shape,
that of the round nose for boring, when used simply as a
roughing tool, the shape b showing it
in place, with the axis of the cutting
angle in the direction of the dotted
line, is better than that of a, because
in b the true cutting edge is carried
**»* forward. Hence, in work-shops the
cutting tools generally take the form b, and the scrapers form^.
Fig. 26 is a square nose for taking finishing cuts, and Fig.
t-,
27 is a tool for scraping; Fig. 28 is a spring tool, also used
for finishing a turned surface; Figs. 29 and 30 are for finish-
ing hollows and rounded parts of work, and are either kept
in different sweeps or ground to circles as wanted. These
Jtn,
latter forms are only used for smoothing and polishing, and,
as they act simply as scrapers, are flat on their upper surfaces.
For grinding tools, a very handy little grind-
stone may be made in this fashion (Fig. 31). A
piece of broken grindstone, 2 inches thick, is
rudely clipped round to 7 inches in diameter, and
a yz inch hole bored through the center with a
common stone-bit; two wooden washers, a'9 }4
inch thick by 4 inches in diameter, also have l/2
So
inch holes bored in their centers. A ^ inch bolt, b, thrust
through the whole keeps them firmly together with the stone
in the center.
As the stone is intended to work chucked between cen-
ters, a small drilled hole is run both into the bolt head and
into the screwed end, and a V shaped slit, c9 is filed in the
head to hold the fork.
^ Turned up in place, it makes an efficient little grindstone,
in readiness for use the moment it is supped into the lathe.
A shallow tin pan slipped between the stone and bed will
catch any mess that may be made.
The grindstone or emery wheel alone is used to sharpen
roughing-down tools; but those used for smoothing and pol-
ishing should have the edge finished with an oil-stone.
NOTES ON BELTING.
Having your machinery, shafting and pulleys properly
arranged, preparatory to belting, the next thing to be deter-
mined is the length and width of the belts. When it is not
convenient to measure with the tape-line the length required,
the following rule will be found of service:
Add the diameter of the two pulleys together; divide the
result by 2> and multiply the quotient by j%> then add this
product to twice the distance between the centers of the shafts^
«nd you have the length required. The width of the belt
depends on three conditions: — I, The tension of the belt; 2,
the size of the smaller pulley and the proportion of the sur-
face touched by the belt; 3, the speed of the belt.
The working adhesion of a belt to the pulley will be in
proportion both to the number of square inches of belt con-
tact with the surface of the pulley, and also to the arc of the
circumference of the pulley touched by the belt. This ad-
hesion forms the basis of all right calculations in ascertaining
the width of belt necessary to transmit a given horse-power.
In locating shafts to be connected by belts, care should be
taken to secure a proper distance one from the other. This
distance should be such as to allow a gentle sag to the belt
when in motion. A general rule may be stated as thus:
When narrow belts are to be run over small pulleys, 15 feet
is a good average, the belt showing a sag of 1% to 2 inches.
For larger belts, working on larger pulleys, a distance of
20 to 25 feet does well, with a sag of 2% to 4 inches.
For main belts, working on very large pulleys, the dis-
tances should be from 25 to 30 feet, the belts working well,
with a sag of 4 to 5 inches.
8i
If the distance be too great the weight of the belt wifl
produce a very heavy sag, which is a decided objection, pro-
ducing great friction on the bearings, while at the same time
the belt will have an unsteady flopping motion which will
destroy both the belt and machinery. Connected shafts
should never be placed one directly over the other, as in that
case the belt must be kept very tight to do the work.
It is best that the angle of the belt with the floor should
not exceed 45 degrees. It is also best in locating the ma-
chinery and shafting so that the belts will run off on opposite
sides, thus relieving the bearings from the friction incident to
having the tension all on one side.
The pulleys should be of as large a diameter as can be
admitted, provided they will not produce a speed of more
than 3,750 feet a minute.
Pulleys should be a little wider than the belts required for
the work.
The motion of driving should run with, and not against ^
the laps of the belts.
In using tightening or guide pulleys, apply them to the slack
side of the belt and near the smallest pulley. Belts to run at
high speed should be made as straight and uniform in section
and density as possible; if practicable, make them endless;
that is, with permanent joints, A loose running belt will last
and wear longer than a tightly-drawn belt. Tightness is evi-
dence of overwork and disproportion. Never add to the ^vork
of a belt so much as to overload it.
The strongest part of a belt leather is near the flesh side,
about one-eighth of the way through from that side.
It is best to run the grain (or hair) side of the belt next to
the pulley.
The flesh side is not liable to .crack, as the grain side will
do when the belt is old ; hence, it is ' better to crimp the
grain instead of stretch ing it.
The grain side next to the pulley will give the belt thirty
per cent, more power than if the flesh side was on the pulley.
The belt, as well as the pulley adheres best when smooth,
and the grain side is the smoother.
A belt adheres much better and is less liable to slip when at
a high speed than at a low speed. Therefore it is best to gear
a mill with small pulleys and run them at high velocity, than
with large pulleys and to run them slower. Besides, the cost
is less, and appearance much neater.
Keep belts clear of grease and accumulation ^
especially from contact with lubricating oi^
82
Protect leather belts from water and moisture.
Belts should be kept soft and pliable.
RULES FOR CALCULATING THE HORSE-POWER. WHICH CAN
BE TRANSMITTED BY BELTING.
To find the horse-power a single b<>lt can transmit > the size
of the pulley and the width of the belt being given. — Multiply
the diameter of the pulley in inches by the number of revolu-
tions per minute; multiply this product by the width of the
belt in inches, and divide by 2,750; the quotient will be the
horse-power.
For' a double belt divide the last product by 1,925 instead
of 2,750.
The horse-poiver to be transmitted \ and the size of the pulley
being known^to find the width of the belt required. — Multiply
the horse-power by 2.750 if the belt is single (by 1,925 if the
belt is double); also multiply the diameter of the pulley in
inches by the revolutions per minute. Divide the first prod-
uct by the last, and the quotient will be the width of belt
required.
The horse-pcnver and width of belt being knoivn, to find the
'diameter of the pulley. — Multiply the horse-power by 2,750
for a single belt (or 1,925 if double); also multiply the revolu-
tions per minute by the width in inches; divide the first prod-
uct by the last, and the quotient will be the diameter of the
pulley in Inches.
7*he horse -power ) diameter of pulley and width of belt being
known j to find the number of revolutions necessary. — Multiply
the horse-power by the 2,750 if a single belt (1,925 if double);
also multiply the diameter of the pulley in inches by the width
ei the belt in inches; divide the first product by the last, and
the quotient will be the number of revolutions per minute
required.
It is assumed in these rules that the belts are open, and
that the pulleys — both driver and driven — are of same
diameter. If, however, the pulleys are of different diameters
the smaller pulley will have less surface in contact with the
belt than on the larger pulley. If this surface — called the
arc of contact, is less than one-half the circumference, the
above rules must be modified. In that case, instead ot using
the numbers 2,750 for single belts, and 1,925 for double belts,
use the following: When the arc of contact of the smaller
pulley is
I
Single
Belt.
the circumference ..... . ............. 6,080
................... 4,730
.................. 4,400
................ 3,850
?
16
/*'
K
.3.220
2,750
Double
Belt.
4?25o
3>310
3,080
2,700
2,390
2,250
1,925
TABLE SHOWING STRENGTH OF HELTIXG MATERIALS.
MATERIALS.
Breaking
Strain for i in.
Wide.
Thickness.
*K)ak- tanned leather
1,250
1-4 in.
*t"Oak- tanned leather
1,166
1-4 in.
•fOak-tanned leather. ...
7^o
1—4 in.
TSucrar-tanned leather
721;
1—4. in.
Ordinary tanned leather
">So
3—16 in.
^3 -ply rubber . .
1,000
7-12 in.
TCotton-duck. . ...
2OO
"fRaw-hide
958
5-32 in.
Flax
1,489
fTests at Centennial Exposition, 1876.
An examination of this table will show that it will be safe
to estimate the breaking strain of leather and rubber belting
at 4,000 pounds to the square inch of section, or 1,000
pounds to each inch of width. Cotton belting is usually laid
4-ply for the narrower widths, making, according to tables, a
breaking strain of 800 pounds to the inch of width. This
brings the three principal materials very near together.
It is usual in allowing for the working strength of belts, to
make the safe working strain i to 16 of the actual breaking
strain, so that we have in this practice, 166 pounds as the
working strain for leather and rubber to each one inch of
width, and 133 pounds for that of 4-ply cotton belting.
84
FEED-WATER HEATERS.
All water used in the generation of steam for mechanical pur.
Doses is more or less heavily impregnated with foreign matter
held in solution; lime, magnesia, sulphur, iron, silica, etc., or
mud, sand and vegetable impurities held in suspension.
Where feed-water is pumped directly into boilers without
first being purified, the heat used for generating steam sets
free all impurities, and they are precipitated upon the inner
surfaces of the boiler in the form of scales or incrustation.
This scale is a non-conductor of heat, and as it is inter-
posed between the water and iron of the boiler, causes a
7 /eat deterioration of the boiler and corroding the iron. Be-
sides, the impurities in the water will cause priming and foam-
ing, which injures the engine by allowing grit to work into
the cylinder, causing explosions, stoppages, delays and ex-
pensive repairs. ->
To eradicate these evils various solutions and patented
nostrums are introduced into the boiler; but this is a danger-
ous and bad practice, as the majority of them are not only
valueless, but injurious. Sal-soda, however, makes a good
purge ) as it is called, and may be used with good effect where
the water causes the boiler to prime or foam.
It is more economical, however, to purify the water before
it is fed into the boiler, and to this end, a good feed-water
heater and filterer is necessary.
The subject of feed-water heaters has not received much
attention until within the last few years, but no plant is now
considered complete without one. Besides purifying the
water, the heater will increase the temperature of the water
from its initial temperature to 200° (in some heaters). This
it does by means of the exhaust steam from the engine pass-
ing through it, and every degree of temperature raised in the
feed -water, is so much clear gain in economy of fuel, as the
table on page 86 will show.
For instance, if the feed- water enters the heater at 60° and
is delivered to the boiler at 1 80°, there is a saving in fuel of
10.46 per cent. If the feed-water enters the heater at 40°
and is delivered to the boiler at 200°, the saving in fuel
would be 13.71 per cent.
The cut of the feed-water heater and purifier represents a,
standard heater called the Excelsior, made in Chicago, and
heats the water up to 212°, or boiling point.
It is thus readily seen that a saving of 13 per cent, in fuel
by the use of a good feed-water heater is a matter of some con*
siderable importance. A further saving, which cannot be so
accurately calculated, is the save in the wear and tear of the
boiler. The forcible injection of a stream of cold water into
a highly heated vessel is bound to make a sudden variation
in the degree of temperature, and any such variation is bound
to affect the boiler to a greater or less extent. Where the
water for steam purposes is drawn from the city pipes, the
consumer is charged for the amount of water he uses, as
measured by the water meter. This expense can be lowered
fully 30 per cent, by using a feed-water heater, into which
the exhaust of the engine passes. The steam is condensed
and is fed back into the boiler again, so that the water, in-
stead of passing into the open air from the exhaust pipe, is
collected and again made to do duty as steam.
&* The feed-water heater should be placed in such a position
as to be easily accessible on all sides, so that it can be readily
and easily cleansed, and the sediment removed without dirty-
ing up the engine or boiler room.
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8?
SETTING SLIDE-VALVES.
We will suppose the engine to be new, and of the rocker
type, and horizontal.
First find in which direction the engine is to run. Set
the crank on the forward dead-center by means of a square,
or by a line. Be sure that it is on the center. Set the eccen-
tric at right angles to the crank, high side turned up. If the
engine was to run the other way the eccentric would have to
be turned down, or the engine turned on the other center.
To get the eccentric accurately at right angles I us 2 the
following method: I get a planed board and fasten it wher-
ever I can, at the eccentric side of the engine, in such ? posi-
tion that it will come under the eccentric rod. I put en ths
straps and rods loosely. I then hold, or fasten a pencil to "h
rod, and have an assistant turn the eccentric once arour/f,
holding the pencil so it will mark the exact travel of the rocf
on the board. I find the center of this line with a pair of
dividers or a rule. I turn the eccentric up until the pencil
comes to the center of line. Fasten the eccentric loosely
so it won't slip. It is now at right angles to the crank, and
in the neutral position. If the valve had no lap nor lead the
eccentric would now be properly set. Next I find the exact
center of the valve and mark it with a fine line in such a
manner that the line will show on top of the valve. I also
find the center of all the parts. I mark a fine line running
up the side of steam-chest so it can be seen above the
valve. I then place the valve over the parts, and bring
line on valve and line on steam-chest, so they are together
This puts the valve in its central or neutral position. I
put in the rod and connect it to rocker-arm. I plumb
the rocker with a plumb-line and bob so that the center of
eccentric rod-pin will be cut by the line, and screw jamb-nuts
up to the valve with my fingers. I now fasten the valve so
it can't move. That is, if I can, without too much trouble.
Valve, rocker and eccentric are now in the neutral position,
and temporarily fastened. The eccentric- rod must now be
brought into such a position that it will hook onto the
rocker-arm without moving it a hair's breadth. I now turn
the eccentric the way the engine is to run until I have the
proper lead or opening. If I have been accurate in my work
the valve is properly set. To prove it I put the engine on
the other center, and if the lead is the same I fasten every-
thing. The valve is set. The distance I turned the eccentric
88
from a right angle with the crank is known as the angle of
advance.
POINTS ON BOILER'S CIRCUMFERENCE.
In text-books we have the areas and circumferences of
circles, but if we don't know how to use them, they are of no
use to us. They are- all right for tin or any thin stuff, but
not for boiler-makers. As an instance, supposing we have a
boiler to make 36" diameter. If we look at the table of cir-
cumference we will find that it takes 113.098" — one hundred
and thirteen inches and about one-sixteenth. This would not
give either side or outside diameter, but would be the thick-
ness of iron, less, if we were wanting inside measurement, or
more, if for outside diameter. If the shell is of ^"material we
must add the %" to the diameter for inside diameter, making
it 36^". For this we will find that it takes 113.883" or a
little over g of an inch more, and for outside diameter we
must take off the thickness of material, making the diameter
35^' • For this it would take 112.312", or about 113^5 as
near as can be got by the common rule. There are several
ways for figuring this. My plan is to multiply the diameter
by three, and divide the same by seven, and add the product
together. But it must be understood that neither this or the
taking from tables in text-books gives laps. In working this
rule, three times 36^ is 108^, and 7 into 36 will go 5 times
and \ over, but instead of calling it \ call it ^, and we have it
on the rule. For the small course there is a difference of six
and one-half times the thickness of material. This will hold
good in all cases, so that if we get one course out by figuring,
the other maybe got by adding or subtracting this difference.
As in the majority of men, they have a holy horror of figures,
especially boiler-makers, in " manufactories. " Another thing
that is not generally understood among them is the properties
of a circle. A circular vessel will contain a greater quantity
than a vessel of any other shape, made of the same amount
of material. That is to say, if an iron plate, six feet long,
was rolled to a circle and a bottom put in it, it would hold
more water than if it was bent square or any other shape.
The areas of circles are to each other as the squares of their
diameters. Any circle twice the diameter of another, is
also four times its area and twice its circumference. The
diameter of a circle is a straight line drawn through its
center, touching both sides. The radius of a circle is half the
diameter, or the distance fro*» ^foe renter to the circumference.
89
HOW TO SET A LOCOMOTIVE ECCENTRIC.
I am familiar with the rule for setting a slipped eccentric
by placing engine on center and marking the stem
by using the eccentric that is not slipped, for a guide, but
what I want is a rule to set a slipped eccentric without
another to go by; suppose I slip both eccentrics on the right
side, what am I to do, and why should I do it? A. — If both
eccentrics on a side slip stop at once, protect your train, and
be sure the eccentrics are slipped, before you go to work on
them; if they are "off" beyond a doubt, take off the chest
cover and pinch the engine onto the center (no matter which
center), take the eccentric next the box first, as you can get the
other out of the way to work at it; if this is the go-ahead ec-
centric, place the reverse lever in forward notch and turn
the eccentric around on the shaft ahead until the port
opens rV' or £", the amount of lead you want, and fasten it
there; put the reverse lever in the back notch and turn the
back-up eccentric back until the port is open, the same as it
was with the go-ahead, and fasten eccentric Where only one
eccentric it slipped, it is best to set it by marking the stem;
that plan is the quickest, as you do not have to take off the
cover. You will readily see that when one side is on the
center, the engine will go either way, as steam is admitted to
one side or the other of the piston on the other side of loco-
motive, as it is in the center of cylinder, and by setting the
eccentrics to give lead on the center, and by turning them
the right way, you can't get them wrong. A good engineer
will always save himself all this trouble and delay on the road
by marking the eccentrics in their proper position, if he is
running a locomotive without eccentric keys.
CHIMNEYS.
The following table shows the proportion of sizes of chim-
neys to the horse-power of the boiler using the chimney.
The measurements given for the diameter is for internal diam-
eter. By referring back to the article on " Steam Boilers"
commencing at page 45, the rules given for fire grate surface
can be utilized in connection with this table in planning for
the steam power of a plant. This table has been carefully
compiled and arranged, and the proportions given may be
accepted as correct. Too little attention is paid to chimneys,
and the furnace is often blamed for poor results when the
ckimney is the part in wrong. Proper draught is all-import-
ant, and one chimney should never be made to do the work
of two.
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External diameter at the base should be one-tenth of the height, unless supported by some other
structure. The" batter" or taper should be from 3-16 to % inch to the foot of each side.
Thickness of brick work, one brick (8 or 9 inches) for 25 feet, from top downward.
If the inside diameter exceed 5 feet, the top length should be i% brick, and if under 3 feet it may
be $£ brick for ten feet.
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HEIGHT OF CHIMNEYS AND COMMERCIAL
HORSE-POWER.
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DEFINITIONS AND USEFUL NUMBERS.
ARITHMETICAL SIGNS USED IN THIS T.OOK.
+ Plus, or more, the sign of addition, as 2 + 2 = 4.
— Minus, or less, the sign of subtraction, as 4 — 2 =2.
X signifies multiplied into or by, as 3 X 3 — 9.
•4- signifies divided by, as lo -4- 5 = 2.
= signifies equality, or equal to, as 4 + 4 = 8.
: :: :, the sign of proportion, as 2 : 4 :: 3 : 6; which reads
thus: as 2 is to 4 so is 3 to 6.
V , the sign of the square root, as A7 49 = 7 ; that is. 7 is
the square root of 49, or 7 is the number which, if multi-
plied by itself, produces 49.
72 means the square of 7, or that 7 is to be squared or multi-
plied by itself. The square of any number is the product
of the number multiplied by itself.
7s means the cube of 7, or that 7 is to be multiplied by 7,
and again by 7. The cube of any number is the product
of that number multiplied by itself, and again by itself.
SQUARE MEASURE AND CUBIC MEASURE.
144 square inches = I square foot.
9 square feet = I square yard.
1,728 cubic inches = I cubic foot.
27 cubic feet = I cubic yard.
DEFINITIONS OF TERMS WHICH ARE EMPLOYED IN THE
FOLLOWING RULES.
A £ & A Point has a position without mag-
nitude, as at c, Fig. i.
S E F A Line has length without breadth,
Figa. 1 and 2. as D E, Pig. 2.
A Right Line is the shortest distance
between any two points, P P, Fig. 3.
fig 3.
A Superficies has length and breadth only.
Fig. 4.
Fig. 4.
92
A Solid has length, breadth and thickness.
Fig- 5-
An Angle is the opening of two lines hav-
ing different directions, and is either Right,
Acute, or Obtuse.
A Right Angle is made by a line being drawn
perpendicular to another, as in Fig. 6. «
Fig. 6*
^S An Acute Angle is less than a Right Angle.
— Fig. 7.
An Obtuse Angle is greater than a Right
Angle. Fig. 8.
A Triangle is a figure bounded by three straight lines.
Figs. 9, 10, ii.
A An Equilateral Triangle is a Triangle of which the
three sides are equal to each other. Fig. 9.
Fig- 9-
An Isosceles Triangle has two of its sides equal.
Fig. 10.
Fig. 10.
A Scalene Triangle has all its sides unequal.
Fig. ii.
Fig. 11.
93
A Right-angled Triangle has one Right Angle.
Fig. 12.
Fig. 12-
A Square is a 4-sided figure having all its sides
equal, and all its angles Right Angles. Fig. 13.
p Fig. 13.
A Rectangle is a 4-sided figure, having its
angles Right Angles, and of which the length
4 exceeds its breadth. Fig. 14.
£ig. 14.
An Arc is any part of the circum-
ference of a circle, as A c B, Fig.
Fig. 15.
A Chord is a right line joining
the extremities of an Arc, as A B,
Fig. 15.
A Segment of a Circle is any part
bounded by an Arc and its Chord,
as the Segment A C B, Fig. 15.
A Diameter is a straight line
passing through the center of a
Circle, and bounded by the circum-
ference at both ends, asG H, Fig. 15.
A Semicircle is half a Circle, as G c II, Fig. 15.
The Circumference of a Circle is the outside boundary line
described on the center with a length equal to the radius.
A Quadrant is a Quarter Circle, as G o I, Fig. 15.
A Tangent is a Right Line that touches a Circle without
C cutting it, as E v, Fig. 15.
3 Concentric Circles are Circles hav-
ing the same center, and the space
included between their circumfer-
ences is called a Ring. Fig. 16.
Fig. 16.
94
USEFUL NUMBERS IN CALCULATION.
Lbs. Pounds x
X
Diameter of Circle X
Circumference X
Cubic inches X
Cubic feet X
Cylindrical in. X
Cylindrical feet X
Diameter of circle X
Side of a square X
.009
.00045 =
3.1416 =
.3183 =
.003607 :
6.232
.002832 =
Square of the )
diameter )
Radius of circle
Cubic inches
Cylindrical inches
Cubic ft. of water
Gallons of water
.88622
1. 128
.7854
6.2831
X
•f- 277.274
+ 353-03
X 35-9
X 10
Hundredweights.
Tons.
Circumference.
: Diameter.
Gallons.
Gallons.
Gallons.
Gallons.
= Side of equal sq.
= Diam. of circle of
equal area.
= Area of circle.
= Circumference.
= Gallons.
= Gallons.
= Tons.
= Pounds weight.
MENSURATION.
To find the circumference of a circle when the diameter is
given. — Multiply the diameter by 3.1416; the product is the
circumference.
A common method of calculating the circumference is to
multiply the diameter by 3, and add \ of the diameter to the
product. The sum is the circumference, very nearly. Or,
what amounts to the same thing, multiply the diameter by
22, and divide the product by 7.
Another method of finding the circumference is to multi-
ply the diameter by 3, and add -fg inch to the product for
every foot-length in the product. ' The reason for adding -fy
inch for each foot of the product, is, that it is the same in
effect as the addition of } of the diameter. As the product
is equal to three times the diameter, the addition to be made
per foot of product should be only a third of the addition
per foot of diameter; that is, instead of } of the diameter,
the addition is ^ of }, or -/,- of the product, which is at the
rate of ^ inch per foot of the product.
To find the diameter of a circle when the circumfer-
ence is given — Multiply the length of the circumference by
the decimal .3183; the product is the diameter.
95
Or, divide the circumference by 3.1416; th£ quotient
is the diameter.
Or, multiply the circumference by 7, and divide the
product by 22; the quotient is the diameter, very nearly.
To find the area of a circle. — Square the diameter — that
is to say, multiply the diameter by itself, cay, in inches
— and multiply the product by the decimal .7854. The
product is the area of the circle in
square inches.
To find the length of an arc of a-
circle. — From 8 times the chord, A
D, Fig. 17, of half the arc A D E,
subtract the chord of the whole arc,
A E, and divide the remainder by 3.
The quotient is the eighth of the
arc, nearly.
Kg. 17.
To find the diameter when the chord of an
arc and the versed sine are given. — Divide
the square of half the chord by the versed
sine, and to the product add the versed
sine. The sum \. s the diameter.
Note. — The versed sine is the height of the
arc.
fo find the area of a segment of a ring. x^^^X
- ^Multiply half the sum of the bounding f ** — *O\
/res by their distance apart; the product *( J* A. X>
is the area. Thus, let the arc A x D be 90 l" T " J "j
inches long, and the arc B c 40 inches long, V ^ — / /
and the distance A B or C D 18 inches long; ^**&~S
then 90" + 40" == 130; and 130 -r- 2 = pjg. ^
65; and 65 X 18" = 1 1 70 square inches,
the area.
To find the area of a segment of a circle. — To z/z °f tne
product of the chord A B and versed ine
n c D of the segment, add the cube of
the versed sine divided by twice the
chord; and the sum is the area, nearly.
Thus —
C Given the chord A B as 20 inches, and
Fig. 20. the versed sine 3 inches; required the
area. 20 X 3 = 60; and 60 X 2 -f- 3
: 40. Then 3 inches cubed =3 X3 X 3 = 9 X 3 = 27;
96
and 27 -f- (20 X 2) = .675; and .675 + 40 = 40.675 = area
nearly.
When the segment is greater than a semicircle, find the
area of the remaining segment and deduct it from the area
of the whole circle, the remainder is the area of the seg-
ment.
To find the area of a sector of a circle. — Multiply half the
length of the arc by the radius of the circle. The product is
the area of the sector. See Fig. 17.
To find the circumference of an ellipse. — Add the two dia-
meters together; divide the sum by 2,
and multiply the quotient by 3.1416.
Or, multiply the sum of the two dia-
-\ HO meters by 1.5708. The product in
^/ either process, is the circumference,
-5 — nearly. Thus — what is the circumfer-
Fi 2i. ence °f an ellipse of which the diameters
are 10 and 14? 14 + 10 = 24; and 24
X 1.5708 = 37.6992; or, 10 + 14 = 24; and 24 -f- 2 = 12;
and 12 X 3.1416= 37.6992 = the circumference of the
ellipse.
Fofind the area of an ellipse. — Multiply the two diameters
together, and multiply the product by .7854. The final
product is the area.
To find the area of a square. — Multiply the length of one
side by itself, or square the side. The product is the area.
For example, a square has each side 12 inches long; what is
the area? 12 X 12= 144 square inches is the area of the
square.
To find the area of a rectangle. — Multiply the length by
the breadth; the product is the area. For example, a rect-
angular plate is 24 inches long and 12 inches wide; what is
the area? 24 X 12 = 288 square inches.
To find the cubic content of a rectangular or cubical body .—
Multiply the length by the breadth, $
and multiply the product by the depth. *~
The last product is the cubic content. .
For example, a box or cistern is 5 feet
long, 2^2 feet wide, and 3 feet deep;
what is the cubic content? 5 feet mul-
tiplied by 2.y2 feet makes an area of 22.
12^ square feet; and \2l/2 feet multiplied by three is equal
to 37^ cubic feet.
97
To find J he cubic content of a square-ended cylinder.—
Find the area of one end by the rule for the area of a circle,
and multiply the area by the length. The product is the
cubic content cf the cylinder.
•Fig. 23.
Note. — The dimensions are to be taken all in inches or all
in feet. The square measure and the cubic measure, corres-
pondingly, will be in inches or in feet.
Example. — A cylinder is 22 inches in diameter and 36
inches in length, what is the cubic content?
22 inches. .7854
22 484
44
44
484
31416
62832
31416
380. 1336 square inches, area of the end.
36
22808016
11404008
13684.8096 cubic inches, solid content.
To find the area of a tn-
angle. — Multiply the length
of the base A B by the perpen-
dicular height c D, and divide
the product by 2. The quo-
tient is the area of the tri-
angle.
When the triangle is equi-
lateral, or equal sided, the area
B
A D
Fig. 24
may be calculated by squaring the side, dividing the square
by 4, and multiplying by 1.732.
To find the cubic content of a sphere. — Multiply the cube
of the diameter by the decimal .5236; the product is the
cubic content. For example, let the diameter be 12 inches.
The cube of 12, or 12 X 12 X 12 = 1728, and 1728 X .5236
= 904. 78 cubic inches.
To find the content of a segment of a sphere. — Square the
radius, or half diameter, of the base, and multiply the square
by 3. To the product add the square of the height of the
segment, and multiply the sum by the height and by the
decimal .5236. The product is the content of the segment.
To find the content of a frustum of a cone. — Square the
diameter of each end, and multiply one diameter by the
other ; add together the two squares and the product, and
multiply the sum by the height of the frustum and by
.2618. The final product is the content.
To find the content of a frustum of a square pyramid.—
Add together the areas of the two ends and the product of
the lengths of side of the ends; multiply the sum of the
height, and divide the product by 3.
PRACTICAL GEOMETRY FOR MECHANICS, EN-
GINEERS, BOILER-MAKERS, ETC.
To bisect a given right line. — That is, to divide it, or
fquare it across in two
^
/
equal parts. Let A B, Fig.
25, be the given right line.
\
/AX
Fig 26.
\
HB
Fig. 25.
Then, with any radius greater than A E— that is greater than
half the length of the line— and on A and B, as centers, de-
scribe two arcs cutting each other at C and D; draw the line
C E D through the intersections. Then c E D will be at right
angles to A E, and the line A B is divided into two equal
parts at E.
99
To draw a perpendicular to a straight line from one of
its extremities. — Let A B, Fig. 26, be the given line, and B the
extremity from which the perpendicular is to be drawn. Take
any point, c, and with the radius c B describe an arc of a
circle, A B D; draw a line from A, through c, cutting the arc
at D; then, a line drawn through the intersection at D
from B will be perpendicular to A B. (
To draw a perpendicular to a right line from a point with-
out the line; that is,
0 when the point is not
on the line. Let A B,
Fig. 27, be the given
line, and c the point
through which the per-
pendicular is to be
j drawn. Then, on C as
~' * a center, with any radi-
us greater than the dis-
tance to the line A B,
describe an arc cutting
\, /* A B at E and D; and on
E and D as centers, with
^ yf any radius greater than
ED, describe two arcs
cutting each other at F
E; a line drawn through F and c will be perpendicular to A B.
To draw a line parallel to
B if y a given straight line. — FIR ST,
" / ..-*"*-.^ to draw the parallel at a giv-
en distance. Let A B, Fig.
28, be the given line. Open
--• i the compasses to the distance
1> required, and from any two
Fig- 28. points, c and D, describe arcs
E and F. Draw the line G H,
touching the arcs. It is the required parallel.
C — £. 5_B SECOND, to draw a parallel
/ ^v* * ' through a given point. Let c,
/ "\x / Fig. 29, be the point. From
j NX-,^ / C draw any line C D to A B.
^*""J = ' J * On C D, as centers, describe
Fig> o0 arcs D E and c F. Cut off D E
equal to c F, and through the
points C and E draw the parallel G H.
A
To draw a rectangle from the center lines. — Draw the line
A B, Fig. 30, equal to one of the center lines, bisect it
£ at C, draw the other
• center line, D E,
through c, at right
angles to A l>; then
with c D as a radius,
and on B and A as
.centers, describe
arcs at H, j, F, and
G; again \\ith C A
as radius, on E and
D as centers, de-
scribe arcs cutting
. the arcs at H, J, F,
: and G. Join the
in t er sect ions by
D
Fig. 30.
straight lines, these will be at right angles and will form a
rectangle.
To draw a square on a given
line. — Let A B, Pig. 31, be the
given line. Erect a perpendicu-
lar at B, and on B as a center,
with B A as a radius, describe an
arc at D, and on D as a center
describe another arc at C. On A
as a center, with the same radius
describe an arc cutting the other
arc at C. Join the intersections FIR. 31.
by straight lines, and the square
is formed. If truly square, it should measure the same length
in the two diagonal directions; that is, the distance A n should
be equal to the distance B c. A
To bisect an angle. — That is, to divide
it in two equal angles. On the point of
the angle, A, Fig. 32, as a center, with
any radius, describe an arc cutting the
sides of the angle at D and E, and on D and
E as centers, describe two arcs cutting each
other at F. The line drawn through A and
E will bisect the angle.
101
Fig. 33.
6Jto;z a given right line to construct
an equilateral triangle. — Let A. B, Fig.
33, be the given right line; then on A
and B, with A B as radius, describe two
arcs cutting each other at c, join A c
and B C, and the triangle ABC, thits
formed, is an equilateral triangle.
In a given circle to inscribe a
square. — Draw any two diameters at
right angles to each other, and join
the extremities, as in Fig. 34.
To inscribe an octagon. — First in-
scribe the square, then bisect the
quarter circles and join the extremi-
ties. Or, bisect the angle A o D, Fig.
34, by the line o F. Then D F is the
length of the side of the octagon.
Fig. 34.
To draw a circle through thrte given points, no matter how
they may are placed. —
This is a very useful
problem, as it enables
any one to determine
the diameter of the circle
of which an arc is a part.
Place the three points, f ,
I, 2, 3, any where. With
any radius greater than
half the distance be-
tween two of the points,
I and 2, and on these
points as centers, de-
scribe two arcs cutting
each other at A and B.
Similarly, describe in-
tersecting arcs on the
points 2 and 3 as cen-
Fig. 35.
ters. Draw straight lines through the intersections respect-
ively, meeting at o. Then o is the center from which the
arc is to be described, with the radius o I, which will pass
through all the three points.
To draw a straight line equal in length to a given arc of
a circle. — Divide the chord A B into
four equal parts; set off one of these
parts from B to c, and join c D. The
line c D is equal to the length of half o
the given arc nearly. Fig. 36.
To describe a rectangle when the length of the diagonal
and that of one of the ends is given. — Draw the diagonal
A B. Bisect it at the center o, and with O A as radius,
describe a circle. Set off the length of the end from A, cut-
ting the circle at D, and from B cutting the circle at c, and
join A c, C B, B D, and D A, to form the rectangle required.
Biff. 87. Fig 3g.
To construct a square whose diagonal only is given. —
Divide the diagonal into seventeen equal parts. Twelve of
these parts are the measure of the side of the square. From
A take up twelve parts in the compasses, and draw arcs of a
circle at B and at c; and on D as a center, with the same
radius, draw arcs, cutting those at
c and D, and join the intersec-
tions to form the square A B D c.
Another method. — Bisect the
diagonal at o, by the perpendicular
line c D; and on the center o and
with the radius o B, describe arcs
at c and D. Join the intersections
to form the square A C B D.
To draiu a square equal in area
to a given circle. — Divide the diame -
ter A B into fourteen equal parts:
set off eleven of these from A to o,
Fifr.39.
io3
and from o draw the perpendicular o c, cutting the circle at
c; and draw A c. Then A c is the side of a square of which
the area is equal to that of the circle. To complete the square,
from c draw a line
through the center
of the circle, cutting
the circumference
at E; and from A
draw the straight line
A E F, through the
point E. This line is
at right angles to A C.
With the radius A c,
and on A as a center,
describe an arc at F ;
Fig. 40.
on F, with the
same radius, draw an
arc at G. From c,
again, draw an arc
cutting the former at
G with the same ra-
dius. Join the in-
tersections, and the
square is completed.
Or, multiply the diameter of the circle by .886226: the
product is the side of a square of equal area.
To draw a square equal in area to a given triangle. — Let
B P A be the given triangle. Draw the perpendicular p c
from the summit P, and bisect it. Produce the side of the
triangle B A, and
set off A E equal to
the half of p c.
Divide E B into
two equal parts at
D; and on D as
center, with D B as
radius, describe
w the semicircle E B.
DC B Draw the perpen-
Fig. 41. dicular A F, cutting
the circle at F ; then A F is the side of a square equal in area
to that of the given triangle.
104
Another method. — A right-angled triangle being given,
to construct a square of the same area. Divide the diagonal
into thirty-four equal parts ; set off ten of these parts from
B
Fig. 42.
A, and ten from B, leaving fourteen in the middle. Draw G C
and G E through the ten divisions, parallel to F E and c F
respectively. The square c F E G has an area equal to that
of the triangle A B F.
To produce a circle equal in area to a given square. —
Given the square A B c D; draw the diagonals and divide
A ^ ^ B
Fig. 43.
half a diagonal, o c, into fifteen equal parts. On o as
center, and with a radius of twelve of these parts, describe
a circle. This circle is of the same area as the square.
Or, multiply the side of the square by 1. 12837. The prod-
uct is the diameter of a circle equal in area to the square of
which the side is given.
IDS
The square is divided
into four triangles, each of
which is one-fourth of the
square in area. The quar-
ter circles, whose figures
differ of course materially
from those of the triangles,
have each the same area as
one of the triangles.
To find the side of a
square which shall con*
tain the area of a given
square any EVEN number
of times. — Draw the given
square A E. The diagonal
F G is the side of a square
I 1 H F
Fig. 44.
of double the area of the given square. Set-off E H, equal to
the diagonal F G; then
the square E B has four
times the area of the
given square. C^ Set-off
again E I, equal to the
diagonal H J of the
square EB, and draw the
square E C on that base;
the square E c has twice
the area of E B, or four
times that of the square
Fig. 45. E A. Set off E L equal to
the diagonal I K; the square E D, erected on that base, has
twice the area of E C.
And so on.
To draw an ellipse
approximately, of a
given length without
regard to breadth. —
\0 Divide the given
length into three equal
parts at o and V; and
on o and v as centers,
with A O as radius,
describe two circles
cutting each other at
I and Kon I and K as
io6
with the diameter of the circle A o v as radius, describe
centers arcs D E F G, to complete the form of an ellipse.
If the radius of the ends is too larg£ and flat, divide the
given length into four equal parts, Fig. 4$A, and describe
three circles as shown; and on H and F as centers, describe
the lateral arcs to touch the first and third circles, and so
complete the figure.
To draw an ellipse when the length and breadth are given
— Draw the diametrical lines at right angles to each other,
intersecting at o. Set out the length and breadth of the
figure on these lines, equally from the center o. Set off the
length o D with the compasses on the longer diameter from
B to E, and on o as a center, with the radius o E, describe the
quadrant E F. Draw the line or chord E F, and set off the
half of it from E to G. On o as a center, with o G as radius,
describe the circle G H j I; then I and G are the centers for
the segmental arcs at A and B, and H and J are the centers for
the lateral arcs at c and D.
TABLE OF SQUARE AND CUBE ROOTS.
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
No.
""""
Square
Root.
Cube
Root.
z
i .
6
2-449
1.817
6.481
3-476
1-16
.031
.020
1-4
2-5
1.832
43
6-557
3.503
1-8
.060
.040
1-2
2.550
1.866
44
3-16
.089
.059
3-4
2-599
1.890
45
6. 708
3-557
.118
.077
7
2.646
1 •9I3
46
6.782
3-583
5-16
.146
•095
2.602
i .935
47
6.856
3-609
3-8
• J73
.112
1-2
2-739
I-957
48
6.928
3-634
7-16
.199
.129
3-4
2. 784
1.979
49
7-
3-659
1-2
.225
•145
8
2.828
2.
So
7.071
3.684
Qr-l6
.250
1-4
2.872
2.021
7.141
3.708
5-8
11-16
•275
-299
!i76
.191
1-2
3-4
2.915
2.958
2.041
2.o6l
52
53
7.211
7.280
r$
3-4
-323
.205
9
3-
2.080
54
7-348
3.780
13-16
.346
.219
3.041
2.098
55
7.416
3-803
7-8
•369
•233
1-2
3.082
2.II8
56
7-483
3.826
15-16
.392
•247
3~4
3. 122
2.136
57
7-550
3-849
2
.414
.260
IO
3.162
2.154
58
7.616
3-871
x-i6
-436
• 273
II
3-3I7
2.224
59
7.681
1-8
.458
.286
12
3-464
2.289
60
7.746
3.9*5
3-16
-479
.298
13
3.606
2.351
61
7.810
3-937
•5
.310
14
3-742
2.410
62
7.874
3.958
5-i6
.521
•322
15
2.466
63
7.937
3-979
3-8
•541
•334
16
4-
2.52O
64
8.
4-
7-16
.561
•346
J7
4.123
2-571
65
8.062
4.021
1-2
.581
-358
18
4-243
2.621
66
8.124
4.041
9-16
.600
-369
IQ
4-359
2.668
67
8.185
4-o6z
5-8
.620
.380
2O
4.472
2.714
68
8.246
4.082
11-16
-639
•391
21
4-583
2-759
69
8.307
4.102
3-4
•658
-402
22
4 -690
2.802
70
8.367
4.12*
13-16
-677
• 412
23
4.796
2.844
8.426
4.141
7-8
-695
• 422
24
4.899
2.885
72
8.485
4.160
15-16
.714
•432
25
5-
2.924
73
8-544
4.179
3
•732
•442
26
5.099
2.963
74
8.602
4-108
x-8
.768
.462
27
5-196
3-
75
8.660
4.217
1-4
.803
.482
28
5.292
3-037
76
8.718
4-236
3-8
•837
•5
29
5.385
3-072
77
8-775
4-254
X-2
.871
. -518
.30
5-477
3-107
78
8.832
4-273
5-8
.904
•535
31
5.568
79
8.888
4.291 ,
3~4
•936
•553
32
5.657
3-175
80
8.944
4-309
7-8
.968
•570
33
5-745
3.208
81
9-
4 327
4
•587
34
5-831
3.240
82
9.056
4-345
.061
•619
35
5.916
3.271
83
9. no
4.362
1-2
.121
-651
36
6.
3-302
84
9.165
4-379
3-4
.179
.681
37
6.083
3-332
85
9.220
4-397-
5
.236
.710
38
6.164
3-362
86
9.274
4.414.
.291
•738
39
6.245
3-391
87
9-327
4-431
1-2
•345
•765
40
6-325
3.420
88
9.381
4.448
3-4
.398
.792
6.403
3-448
89
9-434
4.465
io8
TABLE OF SQUARE AND CUBE ROOTS. — Continued,
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
90
9.487
4.481
138
11.747
5-167
286
13-638
5.708
9i
9-539
4.498
J39
11.789
5.180
287
13-674
5-7x8
92
9-592
4-5I4
140
11.832
5.192
1 88
13.712
5.728
93
9.644
4.531
141
11.874
5.204
289
13-747
5-738
94
9-695
4-547
142
ir .916
5-217
190
13-784
5.748
95
9-747
4-563
143
11.958
5-229
291
13.820
5-758
96
9.798
4-579
144
2.
5-241
292
13-856
5-769
97
9.849
4-595
J45
2.041
5-253
193
23.892
5-779
98
9.899
4.610
146
2.083
5-265
294
23.928
5.788
99
9-950
4.626
M7
2. 124
5-277
195
13.964
5.798
xoo
10.
4.641
148
2 .165
5-289
296
24.
5.808
XOI
0.049
4-057
149
2.206
5-3°i
197
14-035
5-828
202
0.099
4.672
150
2-247
5-3I3
198
24.072
5-828
I03
0.148
4-687
151
2.288
5-325
200
24.142
5-848
104
0.198
4.702
152
2.328
5-335
202
24.212
5.867
105
0.246
4.717
153
12.369
5.348
204
24.282
5.886
106
10.295
4-732
154
12.409
5-36o
206
14-352
5-905
107
o-344
4-747
155
12.449
5-371
208
24.422
5-924
jo8
0.392
4.762
156
12.490
5-383
2IO
14.492
5-943
109
0.440
4.776
157
12.529
5-394
212
14-560
5.962
no
0.488
4.791
158
12.569
5.406
214
24.628
5.981
III
0-535
4-805
159
12.009
5-4I7
216
24.696
6.
222
0-583
4.820
160
12.649
5-428
218
24.764
6.018
"3
0.630
4.834
161
12.688
5-440
220
24.832
6.036
114
0.677
4.848
162
12.727
5-451
222
24.899
6.055
«5
0.723
4.862
163
12.767
5.462
224
24.966
6.073
116
0.770
4.877
164
12.806
5-473
225
15-
6.082
117
0.816
4.890
165
12.845
5-484
226
15-033
6.092
1x8
0.862
4.904
266
12.884
5-495
228
25.099
6.209
«9
0.908
4.918
267
22.922
5-506
230
25.265
6.226
120
o-954
4.632
268
22.962
5-5I7
232
25.232
6.244
221
i.
4.946
269
13-
5-528
234
15.297
6.262
IC2
2.045
4-959
270
13-038
5-539
236
15-362
6-279
«3
1.090
4-973
272
13-076
5-550
238
15-427
6.297
124
2.235
4-986
272
23.214
5-562
240
I5-49I
6.224
125
2.280
5-
173
13-152
5-572
242
15-556
6.23X
126
2.224
5-oi3
174
23.290
5-582
244
25.620
6.248
127
2.269
5.026
175
23.228
5-593
246
25.684
6.265
128
i-3i3
5-039
276
23.266
5.604
248
15.748
6.282
129
1-357
5-052
277
I3-304
5-624
250
25.812
6.299
130
22.402
5.065
278
I3-34I
5-625
252
15-874
6.326
131
"•455
5.078
279
'3.379
5.635
254
z5-937
6.333
232
22.489
5.091
280
13-416
5-646
256
26.
6-349
133
"-532
5.204
282
J3-453
5-656
258
26.062
6.366
134
"-575
5.227
282
23.490
5.667
260
26.224
6.382
*3S
22.628
5.229
183
13-527
5-677
262
26.286
6.398
136
22.662
5.242
284
13-564
5-687
264
26.248
6.415
137
22.704
5-155
*85
23.601
5-698
266
26.309
6.43*
•5
TABLE OF SQUARE AND CUBE ROOTS. — Continued.
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
268
16.370
6.447
360
18.973
7.113
500
22.360
7-937
270
16.431
6.463
361
19.
7. 1 20
505
22 . 472
7.963
272
16.492
6-479
362
19.026
7. 126
22 . 583
7.98?
274
16.552
6-495
364
19.078
7.140
515
22.693
276
16.613
6.510
366
19.131
7-153
520
22.803
8.041
278
16.678
6. 526
368
19.183
7.166
525
22.912
8.067
280
16.733
6.542
370
19-235
7-J79
530
23.021
8.092
282
16.792
6-557
372
19.287
7.191
535
23.130
8.118
284
16.852
6-573
374
19-339
7.204
540
23.237
8.143
286
288
16.911
1 6 Q7O
6.588
6.603
376
078
19.390
7.217
545
23-345
8.168
8 T.Q1
289
iv_>. y/>J
17-
6.610
o/"
380
19-493
7.241
555
23-558
o. iy.j
8.217
290
17.029
6.619
382
19-544
7.225
560
23-664
8.242
292
17.088
6.634
384
19-595
7.268
565
23.769
8.267
294
17.146
6.649
386
19.646
7.281
570
23.874
8.291
296
17.204
6.664
388
19.697
7-293
575
23.979
8.315
298
17.262
6.679
390
19.748
7.306
580
24-083
8-339
300
17.320
6.694.
392
19.798
585
24.186
8.363,
302
I7-378
6.709
394
19.849
7-331
59°
24.289
8.387
3°4
17-435
6.723
396
19.899
7-343
595
24.392
8.410
306
17.492
6.738
398
19.949
£-355
600
24.494
8.434
308
17-549
6-753
400
20.
7.368
605
24.596
8-457
310
.17.606
6.767
402
20.049
7.580
610
24.698
8.480
312
17.663
6.782
404
20.099
7-3^-
615
24.799
8.504
17.720
6.796
406
20.149
7.404
620
24-899
8-527
316
17.776
6.811
408
20.199
7.416
625
25*
8-549
17.832
6.825
410
20.248
7.428
630
25.099
8.572
320
17.888
6.839
412
2O.297
7.441
635
25.199
8-595
322
17.944
6.854
414
20.346
7-453
640
25.298
8.617
324
18.
6.868
416
20.396
7-465
645
8.640
326
18.055
6.882
418
20.445
7-476
650
25.495
8.6*2
328
18.110
6.896
420
20.493
7-488
655
25-592
8.68st
33°
18.165
6.910
422
20.542
7-5
660
25.690
8.706
332
18.220
6.924
425
20.615
665
25.787
8.728
334
18.275
6.938
430
20.736
7-547
670
25.884
8.750
336
18.330
6.952
435
20.857
7-576
675
25.980
8.772
338
18.384
6.965
440
20.976
7.605
680
26.076
8.793
340
18.439
6-979
445
21.095
685
26. 172
8.815
342
18.493
6-993
450
21.213
7-663
690
26.267
8.836
343
18.520
7-
455
21.330
7.691
695
26.362
8 857
344
18.547
7.006
460
21-447
7.719
700
26.457
8.879
346
18.601
7.020
465
21.563
7-747
7°5
26.551
8.900
348
18.654
7-033
470
21 .679
7-774
710
26.645
8.921
350
18.708
7.047
475
21.794
7.802
1 7*5
26.739
8.942
352
18.761
7.060
480
21.908
7.829
720
26.832
8.96a
354
18.8x4
7.074
485
22.022
7-856
i 725
26.925
8.983
356
18.867
7.087
490
22.13£
7.883
730
27.018
9.^04
358
18.920
7,100
I 495
22.248
7 Qi°
1 735
27 no
9.024
tf\
TABLE OF SQUARE AND CUBE ROOTS. — Contimu
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
No.
Square
Root.
Cube
Root.
740
27.202
9-°45
820
28.635
9-359
900
30.
9.654
745
75<>
27-294 .
27.386 <
9.065
9.085
825
830
28.722
28.809
9.378
9-397
905
910
30.083
30.166
9-67*
9.690
755
27.477
9.105
83S
28.896
9.416
915
30-248
9.708
760
27-568
9.125
840
28.982
9-435
920
30-33I
9.725
765
27.658
9-M5
845
29.068
9-454
925
30-413
9-743
770
27.748
9.165
850
29-154
9.472
93°
30.496
9.761
775
780
27-838
27.928
9.185
9.205
855
860
29.240
29-325
9.491
9-509
940
950
30.659
30.822
9-796
9-830
785
28.017
9.224
865
29-410
9.528
960
30.983
9.864
79°
28 . 106
9 244
870
29-495
9.546
970
31 • *44
9.898
795
28.195
9.263
875
29.580
9.564
980
3I-3°4
9.932
800
28.284
9.283
880
29.664
9.582
990
31.464
9-966
805
28.372
9.302
885
29.748
9.600
IOOO
31.623
10.
810
28.460
9.321
890
29.832
9.619
I TOO
33-J66
10.323
«i5
28.548
9-340
895
29.916
9.636
I2OO
34-64I
10.627
HOW TO GEAR A LATHE FOR SCREW
CUTTING.
There is a long screw upon every screw-cutting lathe,
called the lead-screw. This lead-screw feeds the carriage of
the lathe while cutting screws, and has a gear wheel placed
upon its end which takes motion from another gear wheel
attached on the end of the spindle. Each of these gear
wheels contain a different number of teeth, so that different
threads may be cut. All threads are cut a certain number
to the inch, from one to fifty or more. In order to gear your
lathe properly to cut a certain number of threads to the
inch, you will first multiply the number of threads to the
inch you wish to cut by 4, or any other small number, and
this will give you the proper gear to put on the lead-screw.
Now. with the same number, 4, multiply the number of
threads to the inch in the lead-screw, and this will give you
the proper gear to put on the spindle.
Example.— You wish to cut a screw with ten threads to the
inch. Multiply 10 by 4 and it will give you 40; put this gear
on the lead-screw. The lead-screw on your lathe has 7
threads to the inch: multiply 7 by 4, and you will have 28.
Put this gear on your spindle, and your lathe is geared to
cut 10 threads to the inch
Ill
The rule above is for those lathes which have not a stud
grooved into the spindle. As this stud runs with but half
the speed of the spindle, you must change the rule somewhat.
First, multiply the number of threads to the inch you wish
to cut, by 4 (or some other small number), and this will give
you the proper gear to put on your lead-screw. Next multi-
ply the number of threads to the inch on your lead-screw by
the same number, and multiply this product by <?, and this
will give you the proper gear to go on your stud.
Example. — Using same numbers — 10 times 4 is 40. Put this
gear on your lead-screw; 7 times 4 is 28, and 2 times 28 is 56$
put this gear on your stud, and your lathe is grooved to cut
lo threads to the inch.
THE THEORY OK THE STEAM ENGINE.
For many year-; engineers cared nothing about the
theory of the steam ea^ine. They went on improving
and developing it without any assistance from men of pure
science. Indeed it may he said with truth that the greatest
improvement ever effected, the introduction of the com-
pound engine, was made in spite of the physicist, who always
asserted that nothing in the way of economy of fuel was to
be gained by having two cylinders instead of one. In like
manner, the mathematical theorist was content to make cer-
tain thermo-dynamic assumptions, and, reasoning from them,
to construct a theory of the steam engine, without troubling
his head to consider whether his theory was or was not con-
sistent with practice. Within the last few years, however,
the theorist and the engineer have come a good deal into
contact, and the former begins at last to see that the theory
of the steam engine is laid down by Rankine, Clausius, and
other writers, must be deeply modified, if not entirely re-
written, before it can be made to apply in practice We
have recently shown what M. Hirn, who combines in himself
practical and theoretical knowledge in an unusual degree,
has had to say concerning the received theory of the steam
engine, and its utter inutility for practical purposes ; and
papers recently read before the Institutions of Mechanical
and Civil Engineers, and the discussions which followed
them, have done something to convince mathematicians that
they have a good deal to learn yet about the laws which
determine the efficiency of a steam engine. It has always
been the custom to class the steam engine with other heat
engines. It is now known that nothing can be more errone-
ous. The steam engine is a heat engine sni generis, and to
confound it with a hot-air engine, or any motor working
with a non-condensible fluid, is a grave mistake. It is not
too much to say that many engineers now understand the
mathematical theory of the steam engine better than do
men making thermo-dynamics a special study. But there
remains a large number of engineers who do not as yet quite
see their way out of certain things which puzzle them, or
which they fail to understand. There are, indeed, phe-
nomena attending the use of steam which are not yet quite
comprehended by any one, and we may be excused if we say
something about one or two points which require elucidation.
^One of these is the mode of operation of the^' Steam
jacket. It is a very crude statement that it does good be-
cause it keeps the cylinder hot. It might keep the cylinder
hot, and yet be a source of loss rather than gain ; and, a^ a
matter of fact, it is doubtful now if the application of steam
jackets to all the cylinders of a compound engine is advisa-
ble. It is well known, too, that circumstances may arise,
under which the jacket is powerless for good. Thus, for
example, the late Mr. Alfred Barrett, when manager of the
Reading Iron Works, carried out a very interesting series of
experiments with a horizontal engine, in order to test the
value of the jacket. This engine had a single cylinder fitted
with a very thin wrought -iron liner, between which and the
cylinder was a jacket space. The jacket was very carefully
drained, and could be used either with steam or air in it.
Experiments were made on the brake with and without
steam in the jacket. The result was a practically infinitesi-
mal gain by using steam in the jacket. In one word, the
loss by condensation was transferred from the cylinder to
the jacket. On the other hand, it is well known that single
cylinder condensing engines must be steam jacketed if they
are to be fairly economical. Circumstances alter cases, and
the circumstances which attend the use of the jackets a.:--
more complex than appears at first sight.
In considering the nature of the work to be done, we
must repeat a fundamental truth which we have been the first
to enunciate. A steam engine can discharge no water from
it which it did not receive as water, save the small quantity
which results from loss by external radiation and conduction
from the cylinder, and from the performance of work. At
first sight, the proposition looks as though it were untrue.
Its accuracy will, however, become clear when it is carefully
considered. After the engine has been fully warmed up, the
cycle of events is this: Steam is'admitted to the cylir.der from
the boiler. A portion of this is condensed. It parts with
its heat to the metal with which it is in contact. The piston
makes its stroke, and the pressure falls. The water mixed
with the steam is then too hot for the pressure. It boils and
produces steam, raising the toe of the diagram in a way well
understood and needing no explanation here. During the
return stroke the pressure falls to its lowest point, and the
water, being again too hot for the pressure, boils, and is con-
verted into steam, which escapes to the atmosphere or con-
denser without doing work, and is wasteA The metal of the
cylinder, etc., falls to the same temperature as the water.
At the next stroke the entering steam finds cool metal to
come into contact with, and is condensed, as we have said,
and so onfi But the quantity condensed during the steam
stroke is precisely equal to that evaporated during the
114
exhaust stroke, and consequently no condensed steam can
leave the engine as water.
Let us suppose, for the sake of argument, however, that
an engine using 20 Ibs. of 100 Ibs steam per horse per hour,
discharges two pounds of water per horse per hour. As
each of these brought, in round numbers, f 185 thermal units
into the engine, and takes away only 212 units, it is clear
that each pound must leave behind it 973 units ; conse-
quently the cylinder will be hotter at the end of each revolu-
tion than it was at the beginning, and the process would
go on until condensation must entirely cease. It will be
urged, however, that a steam jacket certainly does discharge
water, and that h; considerable quantity, which it did not re-
ceive ; and, as this is apparently indisputable, we are here face
to face with one of tht» puzzles to which we have referred.
The fact, however, is in no wise inconsistent with what is ad-
vanced, v If an engine with an unjacketed cylinder regularly
receives water from the boiler, that engine will discharge
precisely an equal weight of water. The liquid will pass
away in suspension in t he exhaust steam The engine has
no power whatever of converting it into steam. The case
of a jacketed engine is different. Such an engine will evap-
orate in the cylinder water received with the steam, but it
can only do so at the expense of the steam contained in the
jacket. For every i Ib. of water boiled away in the cylinder
I Ib. of steam is condensed in the jacket ; and the corollary
is that, if an engine were supplied with perfectly dry steam,
there would be no steam condensed in the jacket, save that
required to meet the loss due to radiation and the conver-
sion of heat into work. The effect of the jacket will be to
boil a portion of the water during the close of the stroke,
and so to keep up the toe of the diagram, and so get more
work out of the steam. If, however, the steam was deliv-
ered wet to the engine, it is very doubtful if the jacket could
be productive of much economy. The water would be con-
verted into steam during the exhaust stroke, and no equiva-
lent would be obtained for the steam lost in the jacket.
In a good condensing engine about 3 Ibs. of steam per
horse per hour are condensed in the jacket. The cylinder
will use, say, 15 Ibs. of steam, so the total consumption is
1 8 Ibs. per horse per hour. It is none the less a fact, al-
though it is not generally known, that the average Lancashire
boiler sends about 8 per cent, of water in the forif of in-
sensible priming with the steam. Now, 8 per cent, of 1 8
Ibs. i's 1.44 Ibs., so that in this way we have nearly one-half
the jacket condensation accounted for as just explained.
One horse-power represents 2,562 thermal units expended
per hour, or, say, 2.6 Ibs. of steam of 100 Ibs. pressure con-
densed to less than atmospheric pressure; aiid 1.44— •
260= 4. 04 Ibs. per horse per hour, as the necessary jacket
condensation, if no water is to be found in the working
cylinder at the end of each stroke. That this quantity is not
condensed only proves that the water received from the
boiler, or resulting from the performance of work, is not all
re-evaporated.
Something still remains to be written about the true
action of the steam jacket, but this we must reserve for the
present. We have said enough, we think, to show that, as
we have stated, the jacket has more to do than keep the
cylinder hot. With jacketed engines, more than any other,
it is essential that the steam should be dry. In the case of
an unjacketed engine, water supplied from the boiler will
pass through the engine as water, and do little harm; but, if,
the engine is jacketed, then the whole or part of this water
will be converted into steam, especially during the period of
exhaust, when it [can do more good than if it were boiled
away in a pot in the engine room. This is the principal
reason why such conflicting opinions are expressed concern-
ing the value of jackets. That depends principally on the
merits of the boiler.
TREATMENT OF NEW BOILERS.
No ne-.v boiler should have pressure put upon it at once.
Instead, it should be heated up slowly for the first day, and
whether steam is wanted or not. Long before all the joints
are made, or the engine ready for steam, the boiler should
be set and in working order. A slight fire should be
made and the water warmed up to about blood heat only,
and left to stand in that condition and cool off, and absolute
pressure should proceed by very slow stages. Persons who
set a boiler and then build a roaring fire 'under it, and get
steam as soon as they can, need not be surprised to find a
great many leaks developed; even if the boiler does not actu-
ally and visibly leak, an enormous strain is needlessly put
upon it which cannot fail to injure it. Of all the forces en-
gineers deal with, there are none more tremendous than ex-
pansion and contraction.
COMPARATIVE ECONOMY OF HIGH AND
SLOW SPEED ENGINES.
In nearly every case where a flour mill is built, it is
intended to be a permanent investment. The very nature of
the milling business makes it necessary that the plant shall
be built and operated, not for one, two or three years, but
for a long term of years. It is the ambition of every mill
owner, when he builds a mill, to make it the foundation of a
permanent business, and, if he is wise, he will build such a
mill and select such machinery as will prove economical, not
in first cost, but in the long run. In no part, of the milling
plant is this more important than in the power outfit of
steam mills, and, as most of the mills now being built are
steam mills, the comparative economy of different kinds of
steam engines becomes an important subject for considera-
tion. No matter whether the mill is large or small, unless
it is so advantageously located as regards its supply of fuel
that the cost is practically nothing, any wastefulness in the
consumption of fuel creates a steady drain on the earning of
the mill which will seriously affect the balance of the profit
and loss account, and, where fuel is expensive, may result in
transferring the balance to the wrong side ofthe account,
In selecting a power plant, it is a mistake, frequently made,
to consider the first cost of the plant as of the highest
importance, and any saving in this direction as so much
clear gain. Especially is this the case in flouring mills of
small capacity, where the builder's capital is limited, and
where the idea is to get as much mill for as little money as
possible. In such case, any money borrowed from the
power plant to put into the balance of the mill, is bor-
rowed at a ruinously high rate of interest, and it is, more-
over, borrowed without any chance of repayment, except
by throwing out the cheap plant and substituting the
higher priced and more economical one at great expense.
In no way is the miller more often misled than by the
claims of the builders of the high-speed automatic engines,
where the name automatic is relied upon to cover a mul-
titude of sins in the direction of low economy. In this
connection, some facts from a paper by J. A. Powers are
instructive:
After carefully analyzing the problem and considering
the requirements of the load to be driven in electric
lighting stations, which are more favorable for the high
speed engines than is the case in flouring-mill work, Mr.
Powers reaches the conclusion as to the different styles of
engines in t"he consumption of steam, as stated by engine
builders :
Steam per H. P. per hour.
High speed engines 28 to 32 Ibs
Corliss engines, non-condensing 24 to ?6 Ibs.
" < " condensing 20 to 21 Ibs.
compound condensing. 15 to 16 Ibs.
With an evaporation of eight pounds of water per
pound of coal, the coal consumption would be as follows :
Coal per H. P. per hour.
High speed engine 3.50104 Ibs.
Corliss engines, non-condensing 3 to 3.25 Ibs,
" condensing 2.50 to 2.62 Ibs.
" compound condensing 1.87102 Ibs.
As the interest on the first cost of the steam plant should
properly be charged against its economy, the following
statement of comparative first cost is given:
High speed engine $31 to $36 per H. P.
Corliss engines, non-condensing 42 to 46
condensing 43 to 48
" " compound condensing 5210 57 "
The comparison of first cost and fuel saving is as follows :
Coal.
Cost. Consumption.
High speed engine 100 per cent. 100 per cent.
Corliss engine, non-condensing 131 " 62 "
" " condensing 136 " 56
" " compound cond'g.. 163 44
If the cost of coal is taken at $3 per ton and interest i>
figured at six per cent., which figures may be considered a
fair average, the results, based on the foregoing figures, fcr
a plant of 400 horse-power, will be as follows :
Cost of Coal Saving in Coal
per day. over High Speed.
High speed engine $24.75 $
Corliss engine, non-condensing. .. 18.90 5.85
condensing 15-24 9.51
" " com'd condensing 11.64 13.11
Interest Loss in Interest
per day. over High Sp eed.
High speed engine $2.36 $....
Corliss engine, non-condensing 3.08 .72
condensing 3.15 .79
" " com'd condensing. 3.75 1.39
And the saving per day over the high speed engine is:
Corliss engine, non-condensing $ 5.13
" " condensing •' 8.72
" " compound condensing 1172
So far as the steam consumption is concerned, results in
every-day work show that the comparison is made as favor-
able as possible for the high speed engine, for, while records
of actual tests of Corliss engines show that the figures given
are not'understated, the average of high speed engines after
running a short time is not nearly as low as thirty-two
pounds per indicated horse power per hour. So far as the
cost of the respective plants are concerned, we should be
inclined, especially for small plants, to put the average cost
of the high speed plant a little lower than that, of the Corliss a
little higher, but this change would not materially affect the
result so far as comparative economy is concerned.
To bring the matter in shape to fairly apply to the
requirements of the average 100 barrel mill, it may be assumed
that the power required will be 50 horse power. In the
absence of exact data as to the cost of the high speed plant,
and to give it as favorable a showing as possible, the cost of
the respective plants may be stated as follows :
High speed $1,500
Corliss, non-condensing 2,700
condensing 3,200
" compound condensing 4,300
The economy would then be :
Water per Coal per
H. P. per hour. H. P. per hour.
Highspeed 32 Ibs. 4 Ibs.
Corliss non-condensing 26 Ibs. 3.25 Ibs.
" condensing 20 Ibs. 2.5 Ibs.
" compound condensing 16 Ibs. 2. Ibs.
And with coal and rate of interest assumed as above,
based on a continuous run of 280 days, 24 hours per day, the
comparison is summarized as follows :
Cost of
Fuel per Year Interest. Total.
~ High speed $2,016 $90 $2,106
Corliss, non-condensing 1,638 162 1,800
" condensing 1,260 192 J,452
" comp'd condensing 1,008 258 1,266
The ratio of saving to difference in cost between the high
speed plant and the others, may be stated as follows :
Between high speed and Corliss non-condensing, 25 per cent.
" condensing 38^ "
" " comp.condens'g 30 "
Or, in other words, it would take four years to save the
difference in cost using the non-condensing Corliss, a little
over two and one-half years if condensing, and three and one-
half years if compound condensing. In either case, the sav-
ing would be steadily continued, long after the cost of the
plan,t had been wiped out.
U9
RULE FOR SAFETY VALVE WEIGHTS.
There seems to be a steady demand for this rule. The
following is an easily remembered formula which may be of
service to some :
D2 X .7854 X P— D W + F
L = W*
Now, this looks somewhat formidable to those who are
not familiar with calculations in any form, but a few words
and a little study will make it clear to most persons. The
explanation is this :
D2 means that the diameter of the valve is to be multi-
plied by the same figure. If the valve is 4" diameter multi-
ply it by 4. If it is 2" multiply it by 2 ; if ^y2" multiply it
by 3^. This is called squaring the diameter. Now multi-
ply the sum by .7854 and observe the decimal. This gives
the area, as it is called, or number of square ' inches in the
valve exposed to pressure. Of course, the end of the valve
exposed to steam has been measured — not the top of it.
Now multiply the sum last found by the pressure to be car-
ried on the boiler, say 60, if it is 60 pounds. This gives the
force pressing on the bottom of the valve to blow it off its
seat. Take half the weight of the lever and whole weight
of valve and stem from this last sum, and then multiply by
the distance from the center of the valve-stem to the center
of the hole in the short end of the lever. Divide the sum so
found by the whole length of the lever. Then you have the
weight of the ball to go on the end to give 60 Ibs. per square
inch on the boiler.
This is, in brief, the rule ; but it is of no earthly use to those
who are not familiar with ordinary arithmetic, for they will
be very likely to make serious errors in the result by mis-
takes in figuring.
The steamboat inspection law demands that candidates
for marine licenses shall know this rule; but in many cases it
would be just as useful to demand that a man should be able
to jump twenty-five feet from a standstill, for those who are
incompetent can learn the rule as above given, and pass mus-
ter, without being practical working engineers, while those
who have mathematical abilities and practical experience
also, are only affronted by such appeals to the knowledge
they have of their calling.
The qualifications and abilities of engineers for their
positions are in nowise determined by such trifling exercises
as these.
Amount of horse power transmitted by single belts to pul«
leys running 100 revolutions per minute when the diameter of
the driving pulley is equal to the diameter of the driven pulley.
Diameter
of
Pulley.
WIDTH OF BELT IN INCHES,
2
2^2
3
Zl/2 \ 4
4^
5
6
H. P.
In.
H P
H. P.
H P
H. P.
H. P.
H. P
H. P
•44
•54
.65
.76
.87
.98
.09
•31
W
•47
•59
•7i
•83
•95
.07
.19
.42
7
•51
.64
.76
.89
.01
.14
•27
•53
rA
•55
-68
.82
•95
.09
•23
•36
.64
8
•58
•73
.87
.02
.16
•31
•45
• 75
8/2
.62
' -77
•93
.08
,24.
•39
•55
.86
9 ,
•65
.82
.98
•*5
•31
.48
.64
•97
9K
.69
.86
.04
.21
-391 -56
•74
2.08
10
•73
.91
.09
.27
•45
•63
.81
2.18
ii
.8
i.
.2
•4
.6
.8
2.
2.4
12
.87
.09
•31
•53
•75
•97
2.18
2.62
13
•95
.18
•42
•65
.89
2.12
2.36
2.83
H
.02
.27
•52
•77
2.02
2.27
2-53
3-05
r$
.09
•36
.64
.91
2.19
2.46
2-73
3-29
16
.16
•45
•74
2.0^
2.32
2.6l
2.91
3-48
17
•2*
•55
.85
2.16
2.47
2.78
3-09
3-70
18
•31
.64
.96
2.29
2.62
2.95
3-27
3-92
*9
•39
•73
2.07
2.42
2.76
y 1 l
3-45
4.14
20
•45
.82
2.18
2.55
2.9I
3-27
3-64
4-36
21
•52
.91
2.29
2.67
3-05
3-44
3.82
4-58
22
.6
2.
2.4'
2.8
3-2
3-6
4
4-8
23
.67
2.09
2-51
2-93
3-35
3-75
4.18
5.02
24
3-5
4-4
5-2
7-
8.7
10.5
12.2
14.
25
3-6
4-5
5-5
7-3
9.1
10.9
12.7
14-5
26
3-8
47
5-7
7.6
9-5
11.3
I3.2
15.1
27
3-9
4.9
5-9
7.8
9.8
11.8
*3-7
15.6
28
4.1
5-i
6.1
8.1
10.2
12.2
14-3
16.3
29
4-2
5-3
6-3
8.4
10.5
12.6
14.8
16.9
30
44
5-4
6.6
8.7
10.9
I3-I
15-3
17.4.
31
4-5
5-6
6.8
9-
"•3
J3-5
15.8
1 8.
32
4-7
5-8
7-
9-3
ii. 6
14,
16.3
18.6
33
4.8
6.
7-2
9.6
12.
14.4
16.8
19.2
34
4.9
6.2
7-4
9-9
12.4
14.8
17-3
19.8
35
5-1
6.4
7.6
10.2
12.7
!5-3
17.9
20.4
Amount of horse power transmitted by single belts to pul-
leys running 100 revolutions per minute when the diameter of
the driving wheel is equal to the diameter of the driven pulley.
Diameter
of
Pulley.
WIDTH OF BELT IN INCHES.
2
2/2
3
3/2
4
4/2
5
6
In.
H. P.
H. P.
H. P.
H. P.
H. P.
H.P.
H. P.
H. P.
36
5-2
6-5
7.8
10.5
'3-1
15.7
18.3
20.9
37
5-4
6.7
8.1
10.8
13.5
16.2
18.9
21.5
38
5-5
6.9
8.3
ii.
13.8
16.6
'9-3
22.1
39
5-7
7- l
8.5
11.3
14.2
17.
19.9
22.7
40
5-8
7-3
8.7
u. 6
14.6
175
20.4
23-3
42
6.1
7-6
9.2
12.2
'5-3
I&2
21.4
24.3
6.4
8.
9.6
12.8
16.
19.2
22.4
25.6
46
6.7
8.4
10.
13.4
1 6.
20.1
23-4
26.8
48
7-
8.8
10.4
14.
17.4
21.
24.4
28.
50
7.2
9-
10.9
14.6
18.2
21.8
25.4
29.
54
7.8
9.8
ii. 8
I5-6
19.6
23.6
26.4
31.2
60
8.8
10.8
13.1
17.4
21.8
26.2
30.6
34-8
66
9.6
12.
14.4
19.2
24.
28.8
33-6
72
10.4
13.
15.6
21.
26.2
31.4
36.6
41.8
i
11.4
12.2
14-2
15.2
17-
19.4
22.6
24.4
28.4
30.6
34-
36.4
30.8
42.8
45-4
48.6
26
3-8
4-7
5-7
7.6
9-5
"•3
13.2
15.1
27
3-9
4-9
5-9
7.8
9.8
H.8
13-7
15.6
28
4.1
6.1
8.1
10.2
12.2
14-3
16.3
29
4.2
5-3
6.3
8.4
10.5
12.6
14.8
16.9
30
4.4
5-4
6.6
8.7
10.9
13.1
15-3
17.4
4-5
5-6
6.8
9-
II.3
13.5
15.8
1 8.
32
4-7
5.8
7-
9-3
ii. 6
14.
16.3
18.6
33
4-8
6.
7.2
9.6
12.
14.4
16.8
19.2
34
4.9
6.2
7-4
9-9
12.4
14.8
17.3
19.8
35
6.4
7.6
10.2
12.7
15-3
17.9
20.4
36
5-2
6.5
7.8
10.5
I3.I
15-7
18.3
20.9
37
5-4
6.7
8.1
10.8
13-5
16.2
18.9
21.5
38
5-5
6.9
8.3
ii.
13.8
16.6
19-3
22.1
39
5-7
7.1
8.5
11.3
14.2
17-
19.9
22.7
40
5-8
7-3
8.7
u. 6
14.6
17-5
20.4
23-3
42
44
6.1
6.4
7.6
8.
9.2
9.6
12.2
12.8
'I'3
1 6.
18.2
19.2
21.4
22.4
24-3
25-6
HOW TO TRUE AN EMERY WHEEL.
An emery wheel may be trued by using a bar of rough iron
or copper as a turning tool.
122
HOW TO FIND THE DIAMETER OF HIGH AND
LOW PRESSURE CYLINDERS AT DIF-
FERENT PRESSURES.
The following is a table from actual practice giving the
diameters of the high and low pressure cylinders at different
boiler pressures, the piston speed being taken at 420 ft.
minute :
Indicated
horse-power.
PH .
I
.2 &
Q
Boiler pres-
sure 45 Ibs.
Boiler pres-
sure 80 Ibs.
Boiler pres-
Isure 125 Ibs.
Diam. H.P.
cylinder.
Diam. H.P.
cylinder.
Diam. H.P.
cylinder.
10
20
25
3°
40
50
100
150
7X in.
10
nX
I2#
1*
16
22>£
27^
4 in.
&
*>y2
71/*
W
9X
13
16
3^ ^.
\1A
6#
I?
uX
H
3Xin-
4K
S'A
5%
W
7X
10%
™tt
THE LARGEST STEAM BOILER IN AMERICA.
The largest steam boiler ever constructed in America has
been manufactured at Scranton, Pa. The boiler is 35 feet 4
inches in length, 10 feet 6 inches wide, and n feet 6 inches
high. It is made of steel, weighs 45 tons, and is of 1,000
horse-power. One sheet of steel used weighed two tons.
The metal from the " crown sheet " to the " wagon top " is
i y$ inches in diameter, that near the valve is ^ of an inch,
and the other parts 9-16 of an inch in diameter. There are
198 three-inch tubes in the boiler, a double fire box connect-
ing with the flues, and stay bolts and rivets are used varying
in length from six to ten inches.
HOW TO MAKE A STRONG FLANGE JOINT.
To make a flange joint that won't leak or burn out on
steam pipes, mix two parts white lead to one part red lead to
a stiff putty ; spread on the flange evenly, and cut a liner of
gauze wire — like mosquito net wire — and lay on the putty, of
course cutting out the proper holes ; then bring the flanges
*' fair," put in the bolts and turn the nuts on evenly. For a
permanent joint this is A i.
123
DENSITY OF WATER.
Tempera-
ture F.
Comparative
Volume.
Water 32°-=:!.
Comparative
Density.
Water 32°= I.
Weight of
I Cubic Foot.
32
i .00000
.00000
62.418
35
0.99993
.00007
62.422
40
0.99989
.ooou
62.425
45
0.99993
.00007
62.422
46
.00000
.00000
62.418
50
.00015
.99985
62.409
55
.00038
.99961
62.394
60
.00074
.99926
62.372
«5
.00119
.99881
62.344
70
.00160
.99832
62.313
75
.00239
.99771
62.275
80
.00299
.99702
62.232
85
.00379
.99622
62.182
90
.00459
•99543
62.133
95
.00554
.99449
62.074
100
.00639
.99365
62.022
105
.00739
.99260
61.960
no
.00889
.99119
61.868
"5
.00989
.99021
61.807
120
.01139
.98874
6i.7i5
125
.01239
.98808
61.654
130
135
.01390
•01539
.98630
.98484
61.563
61.472
140
.01690
.98339
61.381
145
.01839
.98194
61.291
150
.01989
.98050
61.201
155
.02164
.97882
61.096
160
.02340
.97715
60.941
165
.02589
-97477
60.843
170
.02690
.97380
60 783
175
.02906
.97193
60.665
180
.03100
.97006
60.543
185
.03300
.96828
60.430
190
.03500
.86632
60.314
195
.03700
.96440
60.198
200
.03889
.96256
60.081
205
.0414
.9602
59-937
210
• 0434
.9584
59 822
112
.0444
•9575
59.769
I24
CALKING STEAM BOILERS.
No well-made boiler ought to require to be heavily calked,
and to provide fcfr light calking it is imperative that the
plates of a boiler should be effectually and thoroughly
cleaned of all fire scale before being riveted up. Good boiler
work should be very nearly tight without calking, but it is
difficult to attain this degree of excellence with hand work.
Hydraulic riveting, in which the plates are forcibly pressed
together before the rivet is closed and made to fit the hole,
will, if carefully done, be found to give a tight boiler without
calking. It is obvious that tightness can only be secured by
insuring metallic contact. If all the rivets fill the holes per-
fectly, no leakage can percolate past the rivet heads. If any
rivet heads require calking, they should be cut out and a
fresh rivet inserted, as a leak is a sure indication that the
rivet does not fill the hole, and is possibly imperfectly closed
in addition. It is also obvious that to insure a tight boiler
the surfaces of the plates must be in metallic contact, and
must remain so when the boiler is subjected to the working
pressure which, with the alterations of temperature, will pro-
duce certain inevitable changes in the form of the boiler. It
is obviously necessary
that the surfaces of the
plates should be smooth
in order to insure metal-
lic contact, and that
this cannot be attained
unless the scale covers
the plates completely,
or is wholly detached.
As a slight pin-hole in
the magnetic oxide with
which steel plates are
coated will cause aleak-
age, and under certain
circumstances, set i|3 a
F galvanic and corrosive
IG> 2' action, it is advisable to
wholly detach the scale. This is easily done with iroiv
pUtes, but steel plates cannot be completely cleaned of mag-
n£tic oxide by the usual mechanical methods. An excellent
arid effective method is that used at the Crewe Works of the
London & Northwestern Railway (England). The plates
Are brushed over with muriatic acid diluted with water, and
Applied with a brush or pad made with woolen waste- This
FIG. i.
125
loosens and detaches all the scale, and the plates are then
cleaned by a solution of lime, which effectually removes any
surplus muriatic acid. If the plates are not wanted imme-
diately, they can be protected from rust by a coat of turpen-
tine and oil. If these precautions be not taken, the scale or
dirt upon the plates becomes crushed to powder by the
squeeze of the riveter, and a close metal to metal joint is i en-
deied impossible, and the consequent leakage must be stopped
by calking. With clean plates much calking is not neces-
sary, nor should it be countenanced, for, after all, calking is
only an evidence of, and a concession to, 'more or less in-
ferior, or, at least, imperfect workmanship.
Some boiler-makers firmly believe that calking should be
performed both internally and externally, and we may fre-
quently hear this double calking expatiated upon as adding
to the value of a boiler. As a matter of fact, however, in-
ternal calking should never be resorted to. By internal calk-
ing we mean specially to indicate the calking of edges ex-
posed to steam or water, especially the latter, for long expe-
rience has shown, with very little room for doubt, that internal
calking has frequently been either a cause or an aid in the
initiation of corrosive channeling of the plates along the line
of the rivet seams. Though channeling is commonly met
with along the longitudinal seams, being started, more fre-
quently than by any other cause, by the want of perfect cir-
cularity of the boiler, yet it is aggravated by the calking of
the edge of the plate which borders the channeling, and the
explanation is that an abnormal stress is set up in the plate
upon which the calked edge is forced down, and too fre-
quently the calking toul itself is driven so severely upon the
plate surface as to cause an injury which develops as chan-
neling when other conditions, such as bad water, etc., are
present. These causes have been mainly contributory to the
modern practice of outside calking only, and, with proper
workmanship, this is all that should be required, but the best
practice rejects any calking at all in the strict acceptation of
the term, and demands that the edges of the plates shall be
planed and "fullered;" fullering being the thickening up of
the whole edge of the plate by means of a tool having a face
equal to the plate thickness. With such a tool as this, it is
impossible to wedge apart the plates forming the joint, and
so frequently done in the manner shown (exaggerated) in
Fig. i, when the narrow edge of the calking tool, driven per-
haps by a heavy hammer, actually forces the plates apart and
insures a tight joint only, by the piece of damaged plate corner
which remains driven fast into the gap.
126
In contrast to this, Fig. 2 may be taken to fairly repre-
sent the correct action of the more correct fullering tool, the
plate edge being simply thickened, and contact between the
two plates rendered certain for some distance in from the
edge. To thus thicken, or " fuller " a plate, requires con-
siderable power, and yet, even the use of a more than usually
heavy hammer will not cause injury, as it certainly would do
in careless hands, if used with a narrow calking tool. All
modern first-class boiler work in England is inviarably ful-
lered, and, though the practice of inside calking is still fol-
lowed by firms who " fuller, " nevertheless, outside work is
gaining the day. A further advantage of the " fulling " tool
may be named. If inside calking be still practiced, the
tendency to cause grooving will be less marked than with
the narrow tool, and where, as at times, it is absolutely
necessary to internally calk, as may sometimes happen, the
last is a great point in favor of the broad tool.
The foregoing remarks are suggested by a few notes on
calking in an engineering work, wherein calking tools are
described as having from y% to 3-16 of thickness, and "best
work " as being calked both inside and out. In itself,
calking properly carried out, and lightly performed on good,
close-riveted joints, is not necessarily bad, but too frequently
is badly performed by careless workmen and boys, and hence
" fullering," which is better practice, and is also a safeguard
against carelessness, is to be preferred to the old method.
HOW TO THAW OUT A FROZEN STEAM-PIPE.
A good way to thaw out a frozen-up steam pipe, is to
take some old cloth, discarded clothes, waste, old carpet, or
anything of that kind, and lay on the pipe to be thawed;
then get some good hot water and pour it on. The cloth
will hold the heat on the pipe, and thaw it out in five min-
utes. This holds good in any kind of a freeze, water-wheel,
or anything else.
How many people, outside of practical men, know that
steam is an invisible gas until the moisture it bears is con-
densed l.y contact with cold air. Such is a fact, neverthe-
less, as we may readily see by boiling water in a glass vessel.
The bubbles that rise to the surface of the water are appar-
ently empty — the white vapor appears after they burst iiithe
air at the surface of the water.
THE PREVENTION OF ACCIDENTS FROM RUN*
NING MACHINERY.
A German commission \vas appointed to investigate acci-
dents in mills and factories, and draw up a series of rules fof
their prevention. Some of these rules are as follows:
SHAFTING.
All work on transmissions, especially the cleaning and
lubricating of shafts, bearings and pulleys, as well as the*
binding, lacing, shipping and unshipping of belts, must be
performed only by men especially instructed in, or charged
with, such labors. Females and boys are not permitted to
do this work.
The lacing, binding or packing of belts, if they lie upon
either shaft or pulleys during the operation, must be strictly
prohibited. During the lacing and connecting of belts,
strict attention is to be paid to their removal from revolv-
ing parts, either by hanging them upon a hook fastened to
the ceiling, or in any other practical manner; the same
applies to smaller belts, which are occasionally unshipped
and run idle.
While the shafts are in motion, they are to be lubricated,
or the lubricating devices examined only when observing the
following rules: a. The person performing this labor must
either do it while standing upon the floor, or by the use of b.
Firmly located stands or steps, especially constructed for the
purpose, so as to afford a good and substantial footing to the
workman, c. Firmly constructed sliding ladders, running
on bars. d. Sufficiently 'high and strong ladders, especially
constructed for this purpose, which, by appropriate safe-
guards (hooks above or iron points below), afford security
against slipping.
The cleaning and dusting of shafts, as well as of belt or
rope pulleys mounted upon them, is to be performed only
when they are in motion, either while the workman is
standing : #, on the floor ; or £, on a substantially con-
structed stage or steps ; in either case, moreover, only by
the use of suitable cleaning implements (duster, brush, etc.),
provided with a handle of suitable length. The cleaning of
shaft bearings, which can be done either while standing upon
the floor or by the use of the safeguards mentioned above,
must be done only by the use of long-handled implements.
The cleaning of the shafts, while in motion, with cleaning
waste or rags held in the hand, is to be strictly prohibited.,
All shaft -bearings are to be provided with automatic
Imbricating apparatus.
Only after the engineer has given the well understood
signal, plainly audible in the work-rooms, is the motive en-
gine to be started. A similar signal shall also be given to
a certain number of work-rooms, if only their part of the
machinery is to be set in motion.
If any work other than the lubricating and cleaning of
the shafting is to be performed while the motive engine is
standing idle, the engineer is to be notified of it, and in what
Toom or place such work is going on, and he must then allow
the engine to remain idle until he has been informed by
proper parties that the work is finished.
Plainly visible and easily accessible alarm apparatus shall
be located at proper places in the work-rooms, to be used in
cases of accident to signal to the engineer to stop the
motive engine at once. This alarm apparatus shall always
be in working order, and of such a nature that a plainly
audible and easily understood alarm can at once be sent to
the engineer in charge.
All projecting wedges, keys, set-screws, nuts, grooves, or
other parts of machinery, having sharp edges, shall be sub-
stantially covered.
All belts and ropes which pass from the shafting of one
story to that of another shall be guarded by fencing or
casing of wood, sheet -iron or wire netting four feet six
inches high.
The belts passing from shafting in the story under-
neath and actuating machinery in the room overhead,
thereby passing through the ceiling, must be inclosed with
proper casing or netting corresponding in height from the
flooi to the construction of the machine. When the ^on-
strucHon of the machine does not admit of the introduction
of c&sing, then, at least, the opening in the floor through
which the belt or rope passes should be inclosed with a
low casing at least four inches high.
Fix xl shafts, as well as ordinary shafts, pulleys and fly-
wheels, running at a little height above the floor, and being
within the locality where work is performed, shall be securely
covered.
These rules and regulations, intended as preventions of
accidents to workmen, are to be made known by being con-
spicuously posted in all localities where labor is performed.
ENGINEERS.
The attendant of a motive engine is responsible for the
preservation and cleaning of the engine, as well as the floor
of the engine-room. The minute inspection and lubrication
I29
of the several parts of the engine is to be done before it is
set in motion. If any irregularities are observed during the
performance of the engine, it is to be stopped at once, and
the proper person informed of the reason.
The tightening of wedges, keys, nuts, etc., of revolving
or working part^, is to be avoided as much as possible during
the motion of the engine.
When large motive engines are required to be turned
over the dead point by manual labor, the steam supply valve
is to be shut off.
After stoppage, either for rest or other cause, the engine
is to be started only after .a well-understood and plainly
audible signal has been given. The engineer must stop his
engine at once upon receipt of an alarm signal.
The engineer has the efficient illumination of the engine-
room, and especially the parts moved by the engine, under his
charge.
The engineer must strictly forbid the entrance of unau-
thorized persons into the engine-room.
An attendant of a steam or other power motor, who is
charged with the supervision of the engine as his only duty,
is permitted to leave his post only after he has turned the
care of the engine over to the person relieving him in the
discharge of his duties.
The engineer is charged with the proper preservation of
his engine, and means therefor. He must at once inform
his superior of any defect noticed by him.
The engineer on duty is permitted only to wear closely
fitting and buttoned garments. The wearing of aprons or
neckties with loose, fluttering ends, is strictly prohibited.
GEARING,
Every work on gearing, such as cleaning and lubricating
shafts, bearings, journals, pulleys and belts, as well as the
tying, lacing and shipping of the latter, is to be performed
only by persons either skilled in such work, or charged with
doing it. Females and children are absolutely prohibited
from doing such work.
When lacing, binding or repairing the belts, they must
either be taken down altogether from the revolving shaft or
pulley, or be kept clear of them in an appropriate manner.
Belts unshipped for other reasons are to be treated in the
same manner.
The lubricating of bearings and the inspection of lubri-
cating apparatus must, when the shafting is in motion, be
performed either while standing upon the floor- or by the use
of steps or ladders, specially adapted for this purpose, or
proper staging or sliding ladders. The lubrication of
wheel work and the greasing ol belts and ropes with solid
lubricants is absolutely prohibited during the motion of the
parts.
In case of accident, any workman is authorized to sound
the alarm signal at once by the use of the apparatus
located in the room for this purpose, to the engineer in
charge.
The following rules, classified under proper sub-heads,
are published by the Technische Verein^ at Augsburg:
TO PREVENT ACCIDENT BY THE SHAFTING.
While the shafts are in motion, 51 IB strictly prohibited:
a. To approach them with waste or rags, in order to clean
them. b. In order to clean them, to raise above the floor
by means of a ladder or other convenience.
It is allowable to clean the shafting and pulleys only while
in motion.
These parts of the machinery must be cleaned by means
.:f a long-handled brush only, and while standing upon the
floor.
The workmen charged with these or other functions
about the shafting must wear jackets with tight sleeves, and
closely buttoned up ; they must wear neither aprons nor
neckties with loose ends.
Driving pulleys, couplings and bearings are to be cleaned
only when at rest.
This labor should, in general, be performed only after the
close of the day's work. If performed during the time of
an accidental idleness of the machinery, or during the time
of rest, or in the morning before the commencement of
work, the engineer in charge is to be informed.
HOW TO FIND THE HORSE-POVER OF AN
ENGINE.
Multiply the square of the diameter of the cylinder by
0.7854, and, if the cut-off is not known, multiply the product
by four-fifths of the boiler pressure; multiply the last
product by the speed of the piston in feet per minute (or
twice the stroke in feet and decimals, multiplied by the revo-
lutions per minute). Divide the final product by 33.^00.
and the horse-power will be the answer.
ECONOMY IN THE USE OF AN INJECTOR.
The following is an interesting discussion of the economy
due to the use of an injector, in comparison with a direct-
acting steam-pump, both with and without a feed-water
heater, and a geared pump with heater. Although the in-
vestigation is theoretical, it seems to be based on reliable
data, so that the results, as summarized in the following
table, differ little, in all probability, from the figures which
would be obtained by actual experiment :
Manner of feeding
boiler.
Temperature Relative amount
Per cent, of
of Jeed-
of coal required
fuel saved
water.
for feed
over first
Fahrenheit.
apparatus, in
case.
equal times.
i.
D ir ec t- acting )
steam-pump, V
600
IOO
o.
no heater )
'2.
Injector, no heater
150 o
98-5
1 -5
3-
Injector, w i t h 1
heater \
2OO 0
93-8
6.2
4-
D irec t- acting |
steam-pump, V
2OO 0
87.9
12. I
with heater. . . j
5-
Ge a red-pump, )
a c t u ated by |
*
the main en- }•
2000
86.8
13-3
gi n e , with]
heater J
This does not make the comparison between the eco-
nomical performance of an injector and pump actuated by
the main engine, wi'.hout heater in each case, or, in other
words, he does not consider one of the most general divisions
of the problem. Some experiments made on the Illinois
Central Railroad may be briefly cited to supplement the dis-
cussion. The figures given represent averages of eight trips
of 128 miles in each case :
Pounds of coal per trip. . .
Pounds of water per trip.
Pounds of water evapo-
rated per pound of coal
Feeding
with
pump.
9,529
4S:SS8
5.14
Feeding
with
injector.
8,736
46,826
Per cent,
of grain
for injector
9.08
4.04
5.26 4.28
In the experiments with pump, the trains were slightly
heavier than when the injector \vas used, and more time was
132
lost in switching and standing, for which reason the experi-
menters considered that the economy of coal consumption
for the injector should be reduced from 9.08 to 6.21 per cent.
Some incidental advantages were observed in the case of the
injector, the boiler steamed more freely, and there was less
variation of pressure.
TELEPHONES.
Telephones are of two kinds— magneto and electric. In one
sense of the word they both work on the same principle.
namely: A series of pulsations, corresponding in length and
SECTION OF A BLAKE TRANSMITTER
strength to the sound waves made by the voice, cause simi-
lar pulsations in the receiving end of the telephone circuit,
and these pulsations in turn make sound waves which reach
the ear. Magnetism and electricity work together in a tele-
phone. If a wire is moved just in front of the poles of a
magnet, whether it be an electro or a permanent magnet, a
current of electricity is induced in the wire. If a current of
electricity is set to flowing around a piece of soft iron, that
133
piece of iron becomes an .electro-magnet and remains as such
as long as the electricity flows around it. A steel magnet,
however, is always a mnguet unless particular pains are
taken to de-magnetize it. Around every magnet is a mag-
netic field, and the iield is traversed by what are known as
lines of force. Any change in the lines of force induce elec-
tricity, and this is the bottom principle in the working part
of a telephone. In the receiver of a telephone of the Bell pat-
SECTION OF A BELL RECEIVER.
tern is a bar or straight permanent magnet. At one end of
this bar-magnet is an electro-magnet. Two small copper
wives lead back from the electro-magnet to the closed end of
the receiver and the diaphragm of the telephone fits into the
case so near the poles of the electro-magnet as to almost
touch it. This is a magneto-telephone, and such telephones
are usually used as receivers. When the diaphragm is
moved back and forth by sound waves, it cuts the lines of
force in the magnetic field and induces undulatory currents
134
of electricity, which are transmitted by the telephone wire
to the other telephone. In practice, ho-vever, the imdulatory
currents are induced by the transmitter which is an electric
telephone. The most common type of transmitter in the
United States is the Blake. In this transmitter the working
parts are the diaphragm; touching it is a platinum bottom
which in turn rests lightly against a carbon button. The
current of electricity flows through the carbon button, then
through the platinum bottom and so out to the wires. When
the diagraphragm, vibrating on account of the sound waves
of the voice, presses against the platinum* bottom, it in turn
presses against the carbon button giving it a succession of
little squeezes which make the current of electricity stronger
or weaker, thus producing an unduiatory current. The un-
dulations carried over the wires affect the magnet in the re-
ceiving telephone, causing the diaphragm to respond, thus
reproducing speech at that end of the telephone circuit.
RAPID KAILWAY TRANSIT.
As an illustration of the speed at which railway traveling
can be effected wnen the necessity arises, it may be mentioned
that an American having missed the train in London, and
having to catch an Atlantic steamer at Liverpool, proceeded
by the ordinary train to Crewe, where a special engine had
been chartered to convey him direct to Liverpool. The dis-
tance between Crewe and Liverpool is 36 miles, and one of
the large Crewe engines completed the journey in 33 min-
utes, reaching the landing stage at Liverpool 10 minutes
before the timed departure of his steamer.
USEFUL CEMENTS.
A cement said to resist petroleum is made by taking three
parts resin, one part caustic soda to five of water, boiled to-
gether, the resin being melted first, of course. This makes a
resin soap, to which must be added half its weigh of plaster.
It hardens in forty minute;?. Useful for uniting lamp tops
to glass. Glycerine and litharge, mixed thoroughly, is said
to form a cement which hardens rapidly, and will join iron
to iron or iron to stone. Not affected by water or acids.
A cement for leaky roofs is made by the following articles
in the proportions named: -4 pounds resin, i pint linseed oil,
2 ounces red lead; stir in finest white sand until of the
proper consistency, and apply hot. It possesses elasticity,
and is fireproof.
Starch and chloride of zinc form a cement which hardens
quickly, and is durable. Sometimes used for stopping blow-
holes in castings.
A cement for uniting metal to glass is made with 2 ounces
thick solution of glue, i ounce linseed oil varnish. Stir and
boil thoroughly. The pieces should be tied togeth""' for
three days.
A cement of 100 parts each white sand, litharge ,.nd
limestone, combined with 7 parts of linseed oil, makes the
strongest mineral cement known. At first the mass is soft
and of little coherence, but in six months' time it will, if
pressed, become so hard as to strike fire from steel.
A free application of soft soap to a fresh burn almost
instantly removes the fire from the flesh. If the injury is
very severe, as soon as the pain ceases apply linseed oil, and
then dust over with fine flour. When this covering dries
hard, repeat the oil and flour dressing until a good coating is
obtained. When the latter dries, allow it to stand until it
cracks and falls off, as it will in a day or two, and a new skin
will be found to have formed where the skin was burned.
A new form of electrical railway is being erected at St.
Paul, Minn. The cars do not touch the ground, but are
suspended from girders which form the track and at the
same time the mains conveying the current. Speeds of from
eight to ten miles per hour are expected.
CELLULOID SHEATHING.
Among the various uses of celluloid, it would appear to
be a suitable sheathing for ships, in place of copper. A
French company now undertakes to supply the substance for
this at nine francs p^r surface meter, and per millimeter of
thickness. In experim -,its by M. Butaine, plates of celluloid
applied to various v?s-e!s in January last, were removed fivft
or six months after a id found quite intact and free from
marine vegetation, \\hich was abundant on parts uncovered.
The color of the .substance is indestructible; the thickness
may be reduced to o 0003 meter; and the qualities of elas-
ticity, solidi'y and impevmeability, resistance to chemical
action, etc , a c> a 1 in favor of the use of celluloid.
13*
TRANSMITTING POWER BY A VACUUM.
The idea of producing a vacuum in a receiver or in a sys-
tem of pipes, and utilizing this vacuum to transmit power,
was put forth many years ago. In an article published in
1688 Papin recommends the use of this mode of transmission.
He mentions its advantages, particularly its simplicity and
convenience ; he gives for different cases, the proper diameters
of the pipes in which the vacuum is made, and recommends
lead as the material from which to make them. The idea is
therefore old, but it is only recently that it has been put into
practice. There is now a central station running on this prin-
ciple in Paris, distributing 250 h. p. by means of pipes in
which a seventy-five per cent, vacuum is maintained. One
year ago the company running this station had fifty custom-
ers ; now there are 105 leases signed.
The possibility of maintaining a vacuum in an extensive
system of pipes has sometimes been questioned. Repeated
experiments, however, have shown that in a line of pipes a
third < f a mile long a pressure of a quarter of an atmosphere
can be maintained so that two gauges, one at each end of the
pipe, stand at exactly the same point.
In the station at Paris the exhauster is operated by a
Corliss engine of special construction, the speed of which is
automatically controlled by a regulator operated by the
variations in pressure in the main pipe. The branch pipes are
of lead, and are of different diameters, according to the num-
ber of consumers that each is to supply. Each of these branch
pipes is provided with a cock that can be opened or closed by
means of a wrench that is kept at the central station. The
smaller branches that supply the individua1 ruc "omers are also
of lead, and are likewise provided wich o cks that can be
opened or closed only by the employes of tne company, who
retain possession of the wrenches that open them.
Two kinds of motors are in use, one, the rotary class,
being used for the smaller powers; the other class, which have
cylinders and pistons, being used only for larger powers. The
small motors have an efficiency of about 40 per cent., while
in the largest size the efficiency is said to be as high as 80 per
cent.
SPONTANEOUS COMBUSTION.
No one of average intelligence and information now
believes in the possibility of human beings or the lower ani-
mals undergoing spontaneous combustion ; and yet it is
barely forty years since Liebig devoted a long chapter of his
137
celebrated " Familiar Letters on Chemistry " to exposing the
fallacy of this idea, thus showing that at that date it was preva-
lent. Every reader of Dickens will remember that in one of
his most interesting stories an important episode is made to
turn on the popular belief in spontaneous combustion, a belief
which Dickens himself would seem to have shared. Of
course, as Liebig points out, it requires no explanation
to account for the connection which has often been shown
to exist between death by burning and the too frequent indul-
gence of ardent spirits. Spontaneous combustion, though
not of living animals, may, however, occur in certain cases,
and give rise to fires in buildings, etc., and it may, therefore,
be of interest to the reader to examine shortly some of those
possible cases and their causes. But first of all, a few words
as to " combustion " itself, the true nature of which was
explained by the famous French chemist Lavoisier, toward the
end of last century.
An act of combustion is an act of chemical combina-
tion attended by the evolution of heat and light, and, for such
an act, two conditions are necessary, viz. : (i) There must
be a gas in which the given substance will burn, /'. e. with
which it will combine chemically, and (2) there must be a
certain temperature, the degree of temperature being different
for each different substance. Thus, to take only one common
example, a piece of coal will remain unaltered, at the ordi-
nary temperature of the air, for practically an unlimited
period of time; but, if it be heated to a sufficiently high
temperature, it will burn. /. e. , the carbon of wrhich it is com-
posed will combine with the oxygen of the air, to form car-
bonic acid gas; chemical combination goes on in this case
so rapidly, comparatively speaking, that the heat and light
set free by it are palpable to our senses. Now, the two
requisite conditions just mentioned sometimes occur together
in nature, giving rise to true cases of spontaneous combustion,
of which the following examples may be cited :
1. The ignis fatmiS) or "will-o'-the-wisp," is the effect
of the spontaneous ignition of a volatile compound of phos-
phorus and hydrogen, which is generated, under certain con-
ditions, from decomposing animal and vegetable matter.
This compound has such an intense affinity for the oxygen of
the air, that, ihe moment it comes in contact with ihe latter,
it ignites of itself, giving out the flash of light that has de-
luded so many a wanderer.
2. Spontaneous combustion also occurs not unfrequently
in coal ships, or in the coal bunkers of ordinary vessels. Coal
generally contains iron pyrites or " coal brasses " disseminated
138
through it, and this pyrites, which is a compound of iron and
sulphur, has a great tendency to absorb oxygen from the air
and to combine with it, forming sulphate of iron, or " green
vitriol." This absorption and combination are accompanied
by a rise of temperature, and they sometimes go on so rapidly
as to raise the temperature of the mass sufficiently high to
cause the coal to catch, fire.
3. Fires in buildings are often to be traced to the presence
of heaps of old cotton waste. Such waste is always more or
less impregnated with oil, and, being very loose in texture, it
exposes a large surface to the air. The result is that the oil
rapidly absorbs and combines chemically with the oxygen of
the air, just as the pyrites in coal does, raising the temperature
to such a degree that a fire ensues.
4. The " heating of corn which has been stacked before
the sheaves have been sufficiently dried, and which sometimes
ends in the corn stack catching fire, is the result of chemical
changes of the nature of fermentation.
5. Every one must have observed what a large amount
of heat is set free when lime is slacked — so much, indeed,
that fires have frequently been known to result from it. The
reason of this is, that the lime combines with a certain pro-
portion of water, this act of combination causing much heat
Vo be liberated.
The above instances are sufficient to show that sponta-
neous combustion in no way differs from ordinary combustion,
excepting in that the requisite temperature is attained by
natural causes, and not artificially, and that the old idea held
by the superstitions of last century, that the spontaneous
combustion of animals (which we now know to be impossi-
ble) was caused by a peculiar kind of fire, differing from ordi-
nary fire, and not extinguishable by water, \\as the result of
ignorance. There is still one other cause of spontaneous
combustion, often very dangerous in its effects, and which
leads us on to the subject of explosions, which must be men-
tioned here. One occasionally reads in the newspapers of
explosions occurring in flour mills, sometimes from no appar-
ent cause. These explosions are cases of rapid sponta-
neous combustion, in which a spark from the grindstone sets
fire to the fine flour dust with which the air of the mill is
impregnated.
But what is an "explosion"? An explosion is nothing
more nor less than a combustion which spreads with great
rapidity throughout the whole mass of the combustible matter.
To our senses it appears to be instantaneous, but it is not really
so. An example \viil make this clear. A mixture of hydrogen
339
and oxygeii, or hydrogen and air, is a highly dangerous one,
because the instant that a light is introduced into it it explodes ;
that is to say, the particles of hydrogen and oxygen in the
immediate neighborhood of the flame are raised to the requisite
temperature at which chemical combination can take place
between them. They therefore do combine to form water
vapor, and, by doing so, give out heat enough to cause com-
bination between the particles next to them, and so on
throughout the whole mass of the gas. This action goes on,
as already stated, so rapidly as to be practically instantaneous.
The terrible effects of explosions are caused, then, by the
sudden production of immense quantities of hot gases. ' The
newspapers constantly tell us of disastrous explosions resulting
from the bringing of a light into a room in which an escape of
gas is going on. A mixture of coal gas and air behaves
in precisely the same manner as the mixture of hydrogen
and oxygen, or hydrogen and air, mentioned above, with
the exception that the products of the combustion or ex-
plosion are different. When an escape of gas is suspected, all
lights should be rigorously excluded, the gas turned off at the
meter or main, and windows and doors opened, so as to get
rid of the already-escaped gas as quickly as possible ; and only
then, after complete ventilation has taken place, may a light
be brought into the room with safety. It is to be hoped that
such a technical instruction bill will soon be passed by parlia-
ment as will render avoidable accidents of this nature less and
less likely to occur. It is likewise a dangerous thing to blow out
aparaffine lamp instead of turning the wick down, as, by blow-
ing the flame downward, one is apt to ignite the mixture of
oil, gas and air which is in the upper portion of the oil reser-
voir, and so to produce a serious explosion.
The explosion caused by the ignition of gunpowder or any
other ordinary explosive, is explicable in the same way, but
can only be touched upon in this article. Gunpowder is a
most intimate mixture of charcoal, sulphur and nitre (potassic
nitre), the last named substance being a compound containing
a very large percentage of oxygen, which can be liberated on
heating it. On applying a light to gunpowder," we raise the
temperature sufficiently to allow of the carbon and sulphur
burning in the oxygen liberated from the nitre; and, since the
three substances are so intimately mixed together, this com-
bustion proceeds with explosive rapidity, and produces a rela-
tively enormous quantity of hot gas.
Steel, when hardened, decreases in specific gravity, con-
tracts in length and increases in diameter.
140
RULES FOR THE FIREMAN.
In the care and management of the steam boilef the
first thing required is an unceasing watchfulness — r,vatch-
careis the very word which describes it. The accidents
arising from neglect or incompetency in care of the engine
are few and unimportant compared to those which come
from negligence in attending to the boiler.
Hence the fireman needs to be a man possessed of some
of the highest qualities of manhood. The fact that many of
the best steam engineers in the country have begun their
careers by handling the shovel is evidence that good men
are required and employed in this capacity, and that they
are rewarded for their faithfulness by advancement.
An intemperate, reckless or indifferent man should never
be given this place of trust. The sooner a man is dismissed
who is either of these the better, both for himself and his
employers, to say nothing of the innocent and unsuspecting
public.
!^A.n employer should know something of the character
and habits of the man who does the firing. A daily visit,
and, at irregular times, with an eye to things in the boiler-
room, as well as the engine-room, will keep him posted, to
his great advantage. This regular inspection is most wel-
come to faithful and careful men, and is a great inspiration
to good service. A steam -user should visit his steam depart-
ment as regularly as he does his office, although he may not
spend as much time there. The failure of scores of other-
wise flourishing establishments is due to the waste and
recklessness in the use of fuel under the boilers, or the
heavy losses incurred by repairs and explosions — by which
the whole business is stopped while the expenses continue
undiminished.
A feeling of conscientious responsibility should be the
uppermost thing upon the mind of a fireman when on duty.
He should consider and know how to figure the total tons of
pressure upon the plates of his boiler, and have constantly in
mind the importance of unceasing vigilance.
To know how to be a good fireman cannot be taught by
a book. The knowledge comes by experience and by instruc-
tion of engineers who have themselves been good firemen,
but the following are some of the hints and rules which may
be of advantage to the new beginner. #$
First — The fireman should be a sober and temperate
person. Frivolous or reckless conduct about a steam-boiler
^entirely out of place, and should not be permitted. There
/s too much danger and too much cost — not to call it
waste — of fuel to allow any indifference or recklessness in,
the man upon whom so many depend.
Second — The fireman should be punctual in beginning
his work. A loss of five minutes in starting into vigorous
activity the men and machines of an establishment is some-
times caused by inattention of the fireman, and the blame
which is showered upon him is a stern reminder that he is
held accountable for the loss.
Third — A habit of neatness is an almost necessary qual-
ity, and which pays better for the cost of investment than
any other.
Fourth — The tools should be kept hi their places, and
in good order.
Fifth — The boiler and all its attachments should be kept
in the very tidiest and attractive condition possible.
Sixth — The fireman, notwithstanding its apparent diffi-
culty, should keep himself — as said once — "respectable
abjut his work." Scattered coal and ashes and dripping oil
should be constantly cleaned up, and every effort made to
make the boiler-room an attractive and cheerful place.
Seventh — The fireman needs to know all the details of
his work, and to do with exactness every duty imposed upon
him. He needs to be cool and brave in the presence of
unexpected conditions, such as sudden leaks, breakages of
the glass gauges and sudden stoppages of the engine with a
heavy head of steam on. (
Eighth — He should have an idea of the importance of his
work, and keep in mind to learn to do everything that may
fit him in time for an advanced position.
GRAPHITE IN STEAM-FITTING.
Few steam-fitters or engineers understand the valuable
properties of graphite in making up joints; this valuable
mineral cannot be overestimated in this connection. Inde-
structib'e under all changes of temperature, a perfect lubn
cant and an anti-incrustator, any joint can be mnde up per-
fectly tight with it and can be taken apart years a.ter r.s ensy
as put together. Rubber or metal gaskets, when previous!}
smeared with it, will last almost any length of time, and wiH
leave the surface perfectly clean and bright. Few engineer-
put t> sea without a good supply of this valuable nuiier?!
while i eems to be airr.oot overlooked on shore
142
HORSE POWER — NOMINAL, INDICATED AND
EFFECTIVE, WITH RULES FOR DETERMIN-
ING THE HORSE POWER OF AN ENGINE.
Engineers and others who never carefully considered
the matter, often use the three terms above as synonymous.
While the terms are far from having a like meaning, still we
often hear the nominal horse power of a steam engine spoken
of when the person using the expression really means the
indicated power. To show the distinctive difference between
the meanings of the words nominal, indicated and effective,
as applied to the term horse power, is our aim.
A horse power is merely an expression for a certain
amount of work, and involves three elements — force, space
and time. If the force be expressed in pounds and the space
passed through in feet, then we have a solution of, and
'meaning for, the term foot-pound ; from which it will be
seen that a foot-pound is a resistance equal to one pound
moved through a vertical distance of one foot. The work
done in lifting thirty pounds through a height of fifty feet is
fifteen hundred foot-pounds. Now, if the foot-pounds
required to produce a certain amount of work involve a
specified amount of time during which the work is performed,
and if this number of foot-pounds is divided by the equiva-
lent number representing one horse power (which number
will depend upon the time), then the resulting number will
be the horse power developed.
^ For example, suppose the 1,500 foot-pounds just spoken
of to have acted in one second. To find the horse power
divide by 550, and the result will be the horse power.
A horse power is 33,000 foot-pounds per minute; or, in
other words, 33,000 pounds lifted one foot in one minute, or
one pound lifted 33,000 feet in one minute, or 550 pounds
lifted one foot in one second, etc.
Ths capacity for work of a steam engine is expressed in
the number of horse powers it is capable of developing.
Nominal horse power is an expression which is gradually
going out of use, and is merely a conventional mode of
describing the dimensions of a steam engine for the con-
venience of makers and purchasers of engines. The mode
of computing the so-called nominal horse power was estab-
lished by the practice of some of the early English manu-
facturers, nnd is as follows :
As ume the velocity of the piston to be 128 feet per
minute m'Htipl-ird by the cube root of length of stroke in feet.
Asftn vi- the moral effective pressure to be seven pounds
ner square inch. From these fictitious data and the area of
the piston compute the horse power ; that is, nomma. hors*
power- 7 X 128 X3 \f stroke in feet X area of piston m
square inches-f- 33, ooo. ,
Indicated horse power is the true measure of the work
done within the cylinder of a steam engine, and is based upon
no assumptions, but is actually calculated. 1 he data neces-
sary are : The diameter of the cylinder in inches, length in
feet the me«n effective pressure and number of revolutions
per 'minute. As we have before stated, or implied, work is
force acting through space, and a horse power is the amour
of work in a specified time. In a steam engine the force
which acts is the product of the area of the piston in square
inches multiplied by the mean effective pressure ; the space
is twice the stroke in feet, or one complete revolution, mul-
tiplied by the number of revolutions per minute.
Therefore, indicated horse power equals the area ot tne
piston, multiplied by the mean effective pressure, multiplied
by the piston speed in feet per minute divided by 33,000
Effective horse power is the amount of work which an
engine is capable of performing, and is the difference be-
tween the indicated horse power and horse power required
to drive the engine when it is running unloaded
Engine rating, guarantees, etc., are usually based upon
the indicated horse power, owing to the c:se and accuracy
with which it can be determined, and as a means ot com-
parison.
Nominal horse power is computed from fictitious data.
Indicated hoise power is computed from actual data,
which is arrived at by means of what is known as the steam
engine indicator. .
Effective horse power is computed from actual data,
either by means of the indicator, brake or dynamometer.
THE CARE OF MACHINERY.,
The monev spent in keeping machinery clean and in
order is by no' means wasted. The better the machinery,
the greater the necessity for proper supervision. I he first
knock in an engine, the smallest leak in a boiler, the slight-
est variation from truth in a mill spindle, the wearing down
of roller bearings, heating of journals, should be recti
immediately. The smooth and even working of machinery
has a great deal to do with the cost of driving, while avoid-
ance of the risk of breakage saves a large sum that would
otherwise be spent in i epairs.
144
FOAMING IN BOILERS.
The causes are dirty water; trying to evaporate more
water than the size and construction oi the boiler is intended
for; taking the steam too low down; insufficient steam
room; imperfect construction of boiler, and too small a
steam pipe.
Take a kettle of dirty water and place it on a fire and
allow it to boil and watch it foam, and it will be the same in
a boilei.
Too little attention is paid to boilers with regard to
their evaporating power. Where the boiler is large enough
for the water to circulate, and there is surface enough to
give oft the steam, foaming never occurs. As the particles
of steam have to escape to the surface of the water in the
boiler, unless that is in proportion to the amount of steam
to be generated, it will be delivered with such violence that
the w4t£r will be mixed with it and cause what is called
foaming.
A high pressure insures tranquillity at the surface, and,
the steam itself being more dense, it comes away in a more
compact form, and the ebullition at the surface is no greater
than at a lower pressure. When a boiler foams, we close
the throttle to check the flow, and that keeps up the pres-
sure and lessens the sudden delivery.
> Too many flues in a boiler obstruct the passage of the
C'jeam from the lower part of the boiler on its way to the
surface; this is a fault in construction, but nearly all foaming
arises from dirty water, or -from trying to evaporate too
much water without heating surface or steam room enough.
Usually, when first put in, a boiler and engine are large
enough, but, as business increases, more machinery is added
until the power required is greater than can be furnished by
the engine, more pressure has to be carried, and the number
of revolutions increased; consequently the evaporating
power of the boiler is forced beyond its ability, the steam
being drawn off so rapidly that a large portion of water is
drawn with it — so much that it would astonish any engineer
if he had a testing apparatus attached to the steam pipe.
For the remedy of foul water there are numerous con-
trivances to prevent it from entering the boiler, which is a
farbrtter way than trying to extract the sediment after it is
there — though there are many ingenious methods for doing
ihat also.. Faulty construction, or lack of capacity, the
engineer cannot help, but he soon learns how to run the
boiler to get the best possible results from it.
H5
Every intelligent engineer has observed that his engine
has an individuality not possessed by any other he ever ran,
and nothing but personal acquaintance can get the best work
out of it; so it is with the boiler.
The steam pipe may be carried through the flange six
inches into the dome, which would prevent the water from
entering the pipes by following the sides of the dome as it
does.
For violent ebullition a plate hung over the hole where
the steam enters the dome from the boiler is a good thing,
and prevents a rush of water by breaking it when the throttle
is opened suddenly.
Clean water, plenty of surface, plenty of steam room,
large steam pipes, 'boilers large enough to generate steam
without forcing the fires, are all that is required to prevent
foaming. A surface blow-off is a grand thing, and helps a
foaming boiler, and would be a good thing on every boiler,
as you can tlien skim it as you would an open kettle.
HAND-HOLE PLATES.
They should be placed in such a position as to be accessi-
ble and at or near all those parts of the boiler where scale or
sediment is liable to accumulate In the locomotive station-
ary boiler there should be one in each outside corner of the
fire box and above the bottom ring, and one in each head
under the tubes. In the upright tubular there should be at
least two hand-hole plates above the ring, and one over the
furnace door, on a line with the lower tube sheet, as in the
locomotive boner. The horizontal boiler should have one
in each head under the tubes, and the rule generally observed
is, that, whenever sediment is deposited, then there should be
a hand-hole to get at it for a regular cleaning out.
These plates should be removed once a month, or oftener
if necessary, to keep them clean, and are never considered
an article of ornament, but of primary importance.
BOILING.
Let it be remembered, that the boiling spoken of so often
is really caused by the formation of the steam particles, and
that, without the boiling, there can be but a very slight quan-
tity of steam produced.
While pure water boils at 212°, if it is saturated with
common salt, it boils only on attaining 224°, alum boils at
220°, sal ammoniac at 236°, acetate of soda at 256°, pure
nitric acid boils at 248°, and pure sulphuric acid at 620°
I46
INCRUSTATION OF STEAM BOILERS.
One of the greatest difficulties to be contended against in
steam engineering is the incrustation on the boiler walls, aris-
ing from impure water. This crust is a poor conductor of heat,
and causes increased fuel consumption, as well as the oxidiz-
ing or " burning " of the plates, owing to their increased tem-
perature. A plate of iron 37^ inches thick conducts heat as
well as a " crust " of one inch. A boiler bearing scale only
1-16 inch thick requires 15 per cent, more fuel, with % inch
60 per cent, more, % inch 150 percent, more. If the plates
be clean, 90 pounds of steam require a plate temperature of
only 325° F. ; that is, about 5° above the steam tempera-
ture. But if there be a y2 inch scale, or crust, the plate
must be heated to about 700°, or nearly '• low red " heat.
Now, about 600° iron soon gets granular and brittle; hence
such a scale is dangerous in its results. Crust also retards
the circulation of the water. Two very common ingredi-
ents in boiler scale are carbonate of lime and"sulphate of
lime, or gypsum. The moderate use of soda ash (say one
part in 5?°°° °f water) holds this deposit in check, by pro-
ducing from the principal ingredients a neutral carbonate of
lime, which will not adhere to the plates, when thus rapidly
formed. -Soda ash,' if used in excess, boils up and passes
into the cylinders and pumps, clogging up valves and pistons
by combining with the lubricants. If the gauge-glasses
become muddy, too much soda water is used. It is much
better to supply the boilers with pure water that can deposit
no scale, this being done by means of filters and heaters, or
by surface-condensers, and being especially advisable with
sectional and water tube boilers.
SUPERHEATED STEAM.
Superheated steam is made by drawing steam from the
boiler and heating it after it has ceased to be in contact with
the water in the boiler. The apparatus by which the extra
heat is imparted is called a super-heater. The steam is con-
ducted through the pipes, and hot air and gases of combus-
tion are passed around the outside of them, thus raising the
temperature and forming a more perfect gas.
STEAM GAUGES.
Steam gauges indicate the pressure of steam above the
atmosphere, the total pressure being measured from a per-
fect vacuum, which will add 14 7-10 pounds on the average
to the pressure shown on the steam gauge.
H7
IMPORTANT TO THOSE OPERATING STEAM
BOILERS.
In view of the numerous boiler explosions that have
recently occurred, we submit to them the following perti-
nent questions asked by the American Machinist, which
should command the careful consideration of every steam
user in the land:
How long since you were inside your boiler?
Were any of the braces slack?
Were J«ny of the pins out of the braces?
Did all the braces ring alike?
Did not some of them sound like a fiddle-string?
Did you notice any scale on flues or crown sheet?
If you did, when do you intend to remove it?
Have you noticed any evidence of bulging in the fire-box
plates?
Do you know of any leaky socket bolts?
Are any of the flange joints leaking?
Will your safety valve blow off itself, or does it stick a
little sometimes?
Are there any globe valves between the safety valve and
the boiler? They should be taken out at once, if there are.
Are there any defective plates anywhere about your
boiler ?
Is the boiler so set that you can inspect every part of it
when necessary?
If not, how can you tell in what condition the plates are?
Are not some of the lower courses of tubes or flues in
your boiler choked with soot or ashes?
Do you absolutely know, of your own knowledge, that
your boiler is in safe and economical working order, or do
you merely suppose it is?
HOW TO PREVENT ACCIDENTS TO BOILERS.
I st. Carry regular steam pressure.
2d. Start the engine slowly so as not to make a violent
change in the condition of the water and steam, aiw*. when
consistent, stop the engine gradually.
3d. Carry sufficient water in the boiler.
4th. Do not exceed the pressure in pounds per square
inch allowed to be carried.
5th. See that every appliance of the boiler, feed pipes
and safety-valve, fusible plugs, etc., are in complete working
order.
I48
PRINCIPLES ON WHICH BOILERS AND THEIR
FURNACES SHOULD BE CONSTRUCTED.
Hitherto, those who have made boiler-making a sepa-
rate branch of manufacture, have given too much attention
to mere relative proportions. One class place reliance on
enlarged grate surface, another on large absorbing surfaces,
while a third demand, as the grand panacea, "boiler-room
enough," without, however, explaining what that means.
Among modern treatises on boilers, this principle of room
enough seems to have absorbed all other considerations, and
the requisites, in general term*, are thus summed up :
1. Sufficient amount of internal heating surface.
2. Sufficient roomy surface.
3. Sufficient air-space between the bars.
4. Sufficient area in the tubes or flues ; and
5. Sufficiently large fire-bar surface.
In simpler terms, these amount to the truism — give suf-
ficient size to all the parts, and thus avoid being deficient
in any.
With reference to the proportions of the several parts of
a furnace, there are two points requiring attention ; fust,
the superficial area of the grate for retaining the solid fuel
or coke ; and, second, the sectional area of the chamber
above the fuel for receiving the gaseous portion of the coal.
As to the area of the grate-bars, seeing that it is a
solid body that is to be laid on them, requiring no more
space than it actually covers at a given depth, it is alone
important that it be not too large. On the other hand, as
to the area of the chamber above the coal, seeing that it is
to be occupied by a gaseous body, requiring room for its
rapidly enlarging volume, it is important that it be not too
small.
As to the best proportion of the grate, this will be the
easiest of adjustment, as a little observation will soon enable
the engineer to determine the extent to which he may
increase or diminish the length of the furnace. In this
respect the great desideratum consists in confining that
length within such limits that it shall, at all times,
be well and uniformly covered. This is the absolute
condition and sine qua non of economy and efficiency;
yet it is the very condition which, in practice, is the
i lost neglected. Indeed, the failure and uncertainty which
has attended many anxiously conducted experiments has most
frequently arisen from the neglect of this one condition.
If ihe grate-bars be not equally and well covered, the
149
fr will enter in irregular and rapid streams or masses,
j^rough the uncovered parts, and at the very time when it
should be there most restricted. Such a state of things at
once bids defiance to all regulation or control. Now, on the
control of the supply of air depends all that human skill can
do in effecting perfect combustion and economy ; and, until
the supply of fuel and the quantity on the bars be regulated,
it will be impossible to control the admission of the air.
Having spoken of the grate-bar surface, and what is
placed on it, we have next to consider the chamber
part of the furnace, and what is formed therein. In marine
and cylindrical land boilers, this chamber is invariably made
too shallow and too restricted.
The proportions allowed are indeed so limited as to give
it rather the character of a large tube, whose only function
should be, the allowing the combustible gases to pass through
it, rather than that of a chamber, in which a series of consecu-
tive chemical processes were to be conducted. Such
furnaces by their diminished areas, have also this injurious
tendency, --that they increase the already too great rapidity
of the current through them. ^
The constructing the furnace chamber so shallow an\
with such inadequate capacity, appears to have arisen from
the idea, that the nearer the body to be heated was brought
to the source of heat, the greater would be the quantity
received. This is no doubt true when we present a body to
be heated in front of a fire. When, however, the approach
of the colder body will have the direct effect of interfering
with the processes of nature (as in gaseous combustion), it
must manifestly be injurious. Absolute contact with flame
should be avoided where the object is to obtain all the heat
which would be produced by the combustion of the entire
constituents of the fuel.
So much, however, has the supposed value of near ap-
proach, and even impact, prevailed, that we find the space
behind the bridge, frequently made but a few inches deep,
and bearing the orthodox title of the flame-bed. Sounder
views have, however, shown that it should be made capa-
cious, and the impact of the flame avoided.
As a general view, deduced from practice, it may De
stated that the depth between the top of the bars and the
crown of the furnace should not be less than two feet six
inches where the grate is but four feet long ; increasing in
the same ratio where the length is greater ; and secondly,
that the depth below the bars should not be less, although
depth there is not so essential either practically or chemically.
150
PROPERTIES OF SATURATED STEAM.
PRESSURE.
VOLUME.
Total heat
required
Tempera-
Latent
to generate
By
Steam
Gauge.
Total
ture in
Fahrenheit
Degrees
Com-
pared
. with
Water.
Cubic Feet
of Steam
from i Ib.
of Water.
Heat in
Fahren-
heit
Degrees.
I Ib. Of
Steam from
Water at 32
deig. under
constant
pressure.
In Heat
Units.
o
15
212. 0
1642
26.36
965.2
146.1
5
20
228.0
1229
19.72
952-8
150.9
.0
25
240.1
996
15-99
945-3
154.6
IS
3°
250.4
838
13-46
937-9
157-8
20
35
259-3
726
11.65
931.6
160.5
25
40
267.3
640
10.27
926.0
162.9
3°
45
274.4
572
9.18
920/9
165.1
35
5°
281.0
5i8
8.31
916.3
167. r
40
55
287. i
474
7.61
912.0
169.0
45
60
292.7
437
7.01
908.0
170.7
50
65
298.0
405
6.49
904.2
172.3
55
70
302.9
378
6.07
900.8
173-3
60
75
307-5
353
5-68
897.5
175-2
65
80
312.0
333
5 35
894.3
176.5
70
85
316.1
3U
5-05
891.4
177.9
75
90
320.2
298
4-79
888. s
179-1
80
95
324-1
283
4-55
8858
180.3
85
100
327-9
270
4-33
883.1
181.4
9°
105
33i-3
257
4.14
880.7
182.4
95
I TO
334-6
247
3-97
878.3
183-5
100
H5
338.o
237
3.80
875-9
184.5
no
125
344-2
219
3-5i
871-5
186.4
I2O
135
350.1
203
3-27
867.4
188.2
130
145
355-6
190
3.06
863-5
189.9
140
155
361.0
179
2.87
859-7
I9I-5
150
I65
366.0
169
2.71
856.2
192.9
1 60
175
370.8
159
2.56
852.9
194.4
170
l85
375-3
151
2-43
849.6
195-8
1 80
195
379-7
144
2.31
846.5
197.2
This table gives the value of all properties of saturated
steam required in calculations connected with steam boilers.
SODA ASH IN BOILERS.
An English boiler inspection company recommends that
soda ash be used to prevent scale, instead of soda crystals;
and that it be pumped in regularly and continuously in solu-
tion, with the feed, instead of spasmodically dumped in solid
through the manhole. Tungstate of soda, instead of either
soda ash or soda crystal, has been recommended strongly by
some high authorities in lieu of the above.
STEAM COAL.
Steam coal, being, as everybody knows, unquestionably
the most important and largest expense in the manufacture
of steam, is deserving a most careful investigation by engi-
neers and owners, who, unlike chemists and college pro-
fessors, consider the subject wholly in a practical way, as
relating to the coal bills of their establishments.
Useful knowledge of e very-day economy of coal is seldom
gained by " tests" conducted by experts, for several reasons so
plain that they will not require explanation. 1st. The cost of
the fuel used in tests, whatever may be stated, is too high, aver-
age or " every-day " coal not being used. The experiments
are made with picked men and picked fuel, for brief period*
with everything at its best, and the results attained, iflookt^
for in the ordinary run of business, will be disappointmerj
in the results of the wholesale order. 2d. Men, working rf
firemen, twelve or fourteen hours per day in the hot furnac «
rooms, cannot be expected, with the ordinary appliances, t 4
watch where every lump of coal falls when feeding the fur
nace*, nor to clean the grates any oftener than they are cor*
pelled to do. 3d. Moreover, too many employers favor t\
low wages plan, and, for the apparent saving of a few do"
lars per month, waste many times the amount in the;r fu
nace doors, and render their establishments most disagrt"
able to their neighbors, by a free distribution of unconsmn-^*
carbon, or what is commonly called soot, and of which most
people have no appreciation. 4. Little or no encourage-
ment is given for careful or economical firing, as a rule.
The fireman who oftentimes wastes as much as his entire
wages, secures the same pay as the man working alongside
of him who saves it all. It maybe remarked that this is
" not business," but many are the concerns who run their
steam plants upon this system. Careful handling of coal in
firing pays better than any other thing about a steam plant,
and it is the wisest economy to secure good and careful men
to do it.
As is well understood, the conditions or circumstances
attending the combustion of coal for steam purposes, embra-
ces a wide range. A very few establishments work under
conditions that admit of a high attainment of economy by
having a fixed performance of duty, and their plants well
proportioned to the regular work, but by far the largest
number having a fluctuating demand for steam, and in that
respect are largely at a disadvantage. Many furnaces are
badly constructed., others suffer from an insufficiency of
152
draft, and in many cases there seems to be no end of compli-
cations detrimental to best results.
These practical difficulties and uncertainties, which are well
known to every experienced engineer, render any investiga-
tion worthy of the name, slow and laborious. It has taken
considerable time and research to arrive at the conclusion,
though differing from the preponderance of hearsay
or guess-work evidence, that now, at least, " the highest
priced coal is not the cheapest for steam production^
and that, in fact, the reverse is undoubtedly true, especially
in the Western country Late improvements in the con-
struction of grate bars ha^e undoubtedly added largely to
the value of Western soft coals. The great difficulty, in
former times, of ridding the furnaces of the incombustible
part of these very valuable coals, has now been removed by
improvements, and there is no doubt but what a large num-
ber of extensive establishments in the West are now, and for
some time past have been, obtaining the same duty from the
Illinois bituminous coals that they in former years obtained
from the high-priced Eastern coals.
BLOWING OFF UNDER PRESSURE.
A boiler can be seriously impaired by blowing it down
under a high pressure, and with hot brick work. The heat
from the latter will granulate the iron and reduce its tensile
strength. A boiler should not be blown right down under
a higher pressure than twenty pounds, and not less than four
hours after the fire has been drawn.
When a boiler is exposed to cold air, especially in the
winter, it is advisable that the damper be closed and the
doors thrown open, or vice-versa. If both are left open,
the strong draught of cold air will cool off the flues faster
than the shell; which abuse, if kept up, would reduce the
length of the life of the boiler.
THE TOTAL PRESSURE.
A boiler eighteen feet in length by five feet in diameter,
with forty-four inch tubes, under a head of eighty pounds of
steam, has a pressure of nearly 113 tons on ea^h head, 1,625
tons on the shell and 4,333 tons on the tubes,, making a total
of 6,184 tons on the whole of the exposed surfaces.
This calculation is made by finding the total square inches
under pressure, and multiplying the totals by the pressure, in
this case, 80 pounds to the square inch.
Table Showing Safe Working Steam Pressure for Iron
Boilers of different sizes, using a Factor of Safety of Six.
ill!
J2
.- ""
Longitudinal Seams,
Single Riveted.
Longitudinal Seams,
Double Riveted.
11 .a
H^
Tensil Strength of Iron.
Tensil Strength of Iron.
45,000
50.000
55,°oo
45,000
50,000
55,000
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Lbs.
Press-
Press-
Press-
Press-
Press-
Press-
ure.
ure.
ure
ure.
ure.
ure.
•
36
i
104
I30
116
145
127
159
156
139
174
152
38
7
99
123
1 10
137
121
119
148
132
l64
\ 8 1
40
1
1.17
104
130
H3
113
140
125
I56
138
172
42
X
89
112
99
124
109
136
107
134
149
163
44
1
85
107
95
118
104
130
102
128
114
142
156
46
i
82
102
"3
100
125
98
122
109
136
120
150
X
78
87
96
94
104
115
48
&
98
109
120
118 131
144
y%
118
131
144
142 157
173
yt
75
83
92
90 ; IOO
IIO
5O
94
104
115
113 125
138
y&
112
125
138
134 ! 150
1 66
(
x
72
80
88
86 i 96
106
52 ]
90
100
IIO
108 120
132
}
y%
108
120
132
130 144
158
£
87
96 i
106
101 112
122
54 j
y&
104
116
127
120 134
148
(
\
121
78
135
87
148
95
140 156
94 104
172
114
60 \
H
94
104
113 125
138
I
il>
109
121
134
I31 i H5
160
85
95
104
102 114
125
66
ft
99
in
121
120
133
146
1
/^
112
117
138
137
152
167
3/£
78
87
96
94 i 104
"5
72 •
fe
9I 102
112
IIO 122
134
102 I 117
128
125 ! 140
153
154
STEAM HEATING.
The advantages of steam heating are set forth by Prof.
W. P. Trowbridge, in the North American Review, as
follows :
1. The almost absolute freedom from risk of fire when
the boiler is outside of the walls of the building to be heated,
and the comparative immunity under all circumstances.
2. When the mode of heating is the indirect system,
with box coils and heaters in the basement, a most thorough
ventilation may be secured, and it is in fact concomitant with
the heating.
3. Whatever may be the distance of the rooms from the
source of heat, a simple steam pipe of small diameter con-
veys the heat. From the indirect heaters underneath the
apartments to be heated, a vertical flue to each' apartment
places the flow of the low heated currents of the air under
the absolute control of the occupants of the apartment.
Uniformity of temperature, with certainty of control, may
be thus secured.
4. Proper hygrometric conditions of the air arc better
attained. As the system supplies large volumes of air
heated only slightly above the external temperature, there is
but little change in the relative degree of moisture of the air
as it passes through the apparatus.
5. No injurious gases can pass from the furnace into the
air flues.
6. When the method of heat is by direct radiation in
the rooms, the advantage of steadiness and control of tem-
perature, sufficient moisture and good ventilation, are not
always secured; but this is rather the fault of design, since
all these requirements are quite within reach of ordinary
contrivances.
7. One of the conspicuous advantages of steam heating
is that the most extensive buildings, whole blocks, and even
large districts of a city may be heated from one source, the
steam at the same time furnishing power where needed for
ventilation or other purposes, and being immediately avail-
able also for extinguishing fires, either directly or through
force pumps.
STOPPING WITH A HEAVY FIRE.
When it becomes necessary to stop an engine with a heavy
fire in the furnace, place a layer of fresh coal on the fire, shut
the damper and start the injector or pump for the purpose of
keeping up the circulation in the boiler.
ANALYSIS OF BOILER INCRUSTATION.
BY DR. WALLACE.
Carbonate of lime 64.98
Sulphate of lime 9. 33
Magnesia 6.93
Combined water 3. 15
Chloride of sodium 23
Oxide of iron. 1. 36
Phosphate of lime of alumina 3.72
Silica 6.60
Organic matter 1.60
Moisture at 212 degrees F 2. 10
100.
CLEANING BOILER TUBES.
The method of cleaning boiler tubes depends upon the
kind of fuel used. A steam jet will not answer where wood
and soft coal are used, but will do for hard coal, though in
any case a scraper is indispensable, where a steam jet is not.
Soot and dust will collect in the tubes and burn on so as to
require more than a jet of steam to move it. A steam jet or
blower should be used only where dry steam is at hand, but
by no means with wet steam. Before using the jet, thor-
oughly blow all the water out of it and heat it up. We have
seen some men put the point of the jet in a tube and turn on
steam before warming, and then wonder what caused the brick
work to crumble away at the back end .
CLEANING BRASS.
The government method prescribed for cleaning brass,
and in use at all the United States arsenals, is said to be
the best in the world. The plan is, to make a mixture of
one part of common nitric, and one-half part sulphuric acid
in a stone jar, having also a pail of fresh water and a box of
saw-dust. The articles to be treated are first dipped into
the acid, then removed into the water, and finally rubbed
with the saw- dust. This immediately changes them into a
brilliant color. If the brass has become greasy, it is first
dipped into a strong solution of potash or soda, in warm
water. This dissolves the grease, so that the acid has power
to act.
THE THERMAL UNIT
Is the heat necessary to raise one pound of water at 39° F.
one degree, or to 40° F.
SMOKE — HOW FORMED.
When fresh coal is placed on a fire in an open grate,
smoke arises immediately; and the cause of this smoke is not
far to seek, as it will be easily understood that, before fresh
coals were put upon the fire within the grate, the glowing
coals radiated their heat and warmed the air above, and
thereby enabled the rising gases to at once combine with the
warmed air to produce combustion; but, when the fresh coals
are placed upon the fire, they absorb the heat, and the air
above remains cold.
By gases, is meant the gases arising from coals while on
or near the fire, and it may not be known to every one that
we do not burn coals, oils, tallow or wood, but only the
gases arising from them. This can be made clear by the
lighting of a candle, which will afford the information
required. By lighting the candle, fire is set to the wick,
which, by its warmth, melts a small quantity of tallow
directly absorbed by the capillary tubes of the wick, and
thereby so very finely and thinly distributed that the burning
wick has heat enough to be absorbed by the small quantity
of dissolved tallow to form the same into gases, and these
gases burning, combined with the oxygen in the atmosphere,
give the light of the candle. A similar process is going on
in all other materials; but coal contains already about sev-
enteen per cent, of gases, which liberate themselves as soon
as they get a little warm. The smaller the coal, the more
rapidly will the gases be liberated, so that, in many cases,
only part of the gases are consumed.
The fact is, that the volatile gases from the coal cannot
combine with cold air for combustion. Still combustion
takes place in the following ways. The cold air, in the act
of combination, absorbs a part of the warmth of the rising
gases, which they cannot spare, and, therefore, must con-
dense, so that small particles are formed, which aggregate
and are called smoke, and when collected, produce soot; but
as long as these particles and gases are floating, they cannot
burn or produce combustion, as they are surrounded by a
thin film of carbolic acid. It is only when collected and this
acid driven off, that they are consumed.
It has now been shown that cold is the cause of smoke,
which may be greatly reduced by care. In the open fire
grate the existing fire ought to be drawn to the front of the
grate, and the fresh coal placed behind, or in the back of the
fire The fire in the front will then burn more rapidly,
warm the air above, and prepare the raising gases for com-
157
bustion. in this way smoke is diminished, as the
from the coals at the back rise much more slowly then when
placed upon the fire and the air partly warmed.
WHAT IS LATENT HEAT?
Heat has its equivalent in mechanical work, and, when
heat disappears, work of some kind will take its place.
When a body changes from the liquid to the gaseous form,
the molecules have to be separated and placed in different
positions with regard to each other. This calls for an ex-
penditure of work. This work is supplied by heat, which
disappears at the time. One can hold his hand in steam es-
caping from a safety valve of a boiler for this reason. The
heat of the steam disappears in pushing apart and rearrang-
ing the molecules of the steam as it expands when it leaves
the safety valve.
The term latent heat, as commonly used, means the
amount of heat which disappears when water changes from a
liquid into steam. This is considerable, as will be seen by
consulting any table of the heat contained in steam, and the
water from which it comes.
Water at 212° contains 180 units of heat. Steam at
212° contains 1,146 units of heat. The latent heat is the
difference of 966 links. Such a large quantity disappears
when liquid water changes to steam, that boiling cannot be
raised above 212°, no matter how hard it is boiled. The
heat becomes latent, and the mechanical work, or rather
molecular work, is sufficient to take up all that is supplied by
the fire.
The specific heat of air at constant pressure being
0.2377, the specific heat of water, which is i, is, therefore,
4.1733 times greater under ordinary circumstances. A
pound oi water losing i° of heat, or one thermal unit, will
consequently raise the temperature of 4.17 pounds, or, at
ordinary temperatures, say 50' of air, i°. A pound of steam
at atmospheric pressure, having a temperature of 212° F.,
in condensing to water at 212° F., yields 966 thermal units,
which, if utilized, would raise the temperature of 5X966=
4830' of air i°, or about 690' from 5° to 70° F.
i58
MISTAKES IN DESIGNING BOILERS.
One of the greatest mistakes that can be made in design-
ing boilers, and the one that is most frequently made of any,
consists in putting in a grate too large for the heating sur-
face of the boiler, so that with a proper rate of combustion
of the fuel an undue proportion of the heat developed passes
off through the chimney, the heating surface of the boiler
being insufficient to permit its transmission to the water.
This mistake has been so long and so universally made, and
boiler owners have so often had to run slow fires under their
boilers to save themselves from bankruptcy, that it has given
rise to the saying, " Slow combustion is necessary for econ-
omy." This saying is considered an axiom, and regarded
with great veneration by many, when the fact is, if the
truth must be told, it has been brought about by the waste-
fulness entailed by boiler plants and proportioned badly by
ignorant, boilermakers and ignorant engineers, who ought to
know better, but don't.
Let us consider the matter briefly : Suppose we are
running the boiler at a pressure of 80 tbs. per square inch,
the temperature of the steam and water inside will be about
325 degrees F. ; the temperature of the fire in the furnace
will, under ordinary conditions, be about 2,500 degrees F.
Now, it should be clear to the dullest comprehension, that
we can transmit to the water in the boiler only that heat due
to the difference between the temperature in the furnace and
that in the boiler. In case of the above figures, about
seven-eighths of the total heat of combustion is all that
could, by any possibility, be utilized, and this would require
that radiation of heat from every source should be absolutely
prevented, and that the gases should leave the boiler at the
exact temperature of the steam inside, or 325 degrees.
To express the matter plainly, we may say that the
utilization of the effect of a fall of temperature of 2.175
degrees is all that is possible.
Now, suppose, as one will actually find to be the case in
many cases if he investigates carefully, that the gases leave
the flues of another steam boiler at a temperature between
500 and 600 degrees. The latter temperature will be found
quite common, as it is considered to give "good draft."
This is quite true, especially as far as the " draft " on the
owner's pocket-book is concerned, for he cannot possibly
utilize under these conditions more than 2,500 — 500=2,000
degrees of that inevitable difference of temperature to which
he is confined, or four-fifths of the total, instead of the
seven-eighths, as shown above, where the boiler was running
just right, and any attempt to reduce the temperature of the
escaping gases by means of slower " combustion," as he
would probably be advised to do by nine out of ten men,
would simply reduce the temperature of the fire in his fur-
nace, and the economical result would be about the same.
His grate is too large to burn coal to the best possible ad van-
tage, and his best remedy is to reduce its size and keep his
fire as hot as he can.
This is not speculation, as some may be inclined to think.
Direct experiments have been made to settle the question.
The grate under a certain boiler was tried at different sizes
with the following result:
With grate six feet long ratio of grate to heating surface
was i to 24.4.
With grate four feet long ratio of grate to heating surface
was o to 36.6.
The use of the smaller grate gave, with different fuels and
all the methods of firing, an average economy of nine per
cent, above the larger one, and, when compared by burning
the same amount of coal per hour on each, twelve per cent.
greater rapidity of evaporation and economy were obtained
with the smaller grate.
AVERAGE BREAKING AND CRUSHING STRAINS
OF IRON AND STEEL.
Breaking strain of wrought iron = 23 tons'")
Crushing strain of wrought iron = 17 tons |
Breaking strain of cast iron about 7^ tons PPer square inch
Crushing strain of cast iron =50 tons. . . . j of section.
Breaking strain of steel bars about 50 tons
Crushing strain of steel bars up to 116 tonsj
PITTING OF MUD DRUMS.
Mud drums have frequently been known to pit through
their close connection to the brick work with which they
are covered. When the boiler is filled with cold water, the
iron will sweat. This moisture mixing with the lime of the
brick work will, after a length of time, injure the iron*
Mud drums are injured on the inside by a similar chemical
action. The sediments of lime, etc., deposit there where
their action goes on undisturbed by any circulation. To
prevent pitting on the inside from this cause, blow down fre-
quently, and, on the outside, keep the brie1* off the rxlates,
so that all moisture can pass off.
i6o
TABLE OF SPECIFIC GRAVITIES.
Weight of a Cubic
Inch in Lbs.
Copper, cast 3178
Iron, cast 263
Iron, wrought 276
Lead ; 4103
Steel 2827
Sun-metal 3177
DIVISIONS OF DEGREES OF HEAT.
The thermometer is an instrument for measuring sensible
heat. It consists of a glass tube of very fine bore, terminat-
ing in a bulb. This bulb is filled with mercury, and the top
of the tube is hermetically sealed after all the air has been
expelled. The instrument is then put into steam arising
from boiling water and, when the barometer stands at thirty
inches, a mark is placed on a scale affixed opposite the place
the mercury stands at. It is again put in melting ice, and
the scale again marked. The space between these marks is
divided into spaces called degrees. In this country and
England it is divided into 180 equal parts, calling freezing
point 32°, so that the boiling point is 212° ; and zero or o is
32° belowfreezing point, and this scale is called Fahrenheit's.
On the continent two other scales are in use; the Centi-
grade, in which the space is divided into 100 equal parts,
hence the name ; and Reaumur's, in which the space is
divided into 80. In both of these scales freezing point is o,
or zero ; so that the boiling point of centigrade is 100°, and
Reaumur 80°.
THE LAW OF PROPORTION IX STEAM
ECONOMY.
The basis of steam engineering science consists in closely
adhering to the absolute ratio or proportion of the different
parts of the steam-plant, representing the power of the en-
gine and boiler to the amount of the work to be done. To
use an extreme illustration, it is not scientific to construct a
^hundred horse power boiler — say j ,500 square feet of heating
Surface — to furnish steam for a six-inch cylinder; nor is it in
proportion to use a cylinder of the latter size to drive a
sewing machine. It may be said truthfully that the law of
true proportion between boiler, engine and the desired
amount of work is less understood than almost any other in
the range of mechanical practice.
101
VALUABLE INFORMATION FOR ENGINEERS.
To find the capacity of a cylinder in gallons, multiply the
area in inches by the length of stroke in inches, and it will
give the total number of cubic inches; divide this by 231,
a:.d you will have the capacity in gallons.
The U. S. standard gallon measures 231 cubic inches, and
contains 8^ pounds of distilled water.
The mean pressure of the atmosphere is usually estimated
at 14.7 pounds per square inch.
The average amount of coal used for steam boilers is 12
pounds per hour for each square foot of grate.
• The average weight of anthracite coal is 53 pounds to one
cubic foot of coal ; bituminous, about 48 pounds to the cubic
foot.
Locomotives average a consumption of 3,000 gallons of
water per ico miles run.
To determine the circumference of a circle, multiply the
diameter by 3. 1416.
To find the pressure in pounds per square inch of a
column of water, multiply the height of the column in
feet by .434, approximately, every foot elevation is equal to
l/2 1 pound pressure per spare inch, allowing for ordinary
friction.
The area of the steam piston, multiplied by the steam
pressure, gives the total amount of pressure that can be
exerted. The area of the water piston, multiplied by the
pressure of water per square inch gives the resistance. A
margin must be made between the power and t"he resistance
to move the pistons at the required speed, from 20 to 40 per
cent., according to speed and other conditions.
To determine the diameter of a circle, multiply circum-
ference by .31831.
Steam at atmospheric pressure flows into a vacuum at the
rate of about 1550 feet per second, and into the atmosphere
at the rate of 650 feet per second.
To determine the area of a circle, multiply the square of
diameter by .7854.
A cubic inch of water evaporated under ordinary atmos-
pheric pressure is converted into one cubic foot of steam
(approximately).
By doubling the diameter of a pipe, you will increase its
capacity four times.
In calculating horse-power of tubular or flue boilers, con-
sider 15 square feet of heating surface equivalent to one
nominal horse-power.
1 62
HOW TO TEST BOILERS.
The safe- working pressure of any boiler is found by
multiplying twice the thickness of plate by its tensile
strength in pounds, then divide by diameter of boiler,
then this result divide by six. This gives safe working
pressure.
EXAMPLE.
Twice thickness plate X tensile strength -5- diameter of
boiler in inches-5-6=safe working pressure + one-half more
= maximum test pressure.
Diameter of boiler, 60". Thickness of plate, yz",
Tensile strength of plate, 60,000 Ibs. i "X 60,000-— 60 =
1,000-7-6=166% Tbs., which. is the safe working pressure-f
83^ Ibs. = 250 ft>s., which is the maximum test pressure.
After the safe pressure has been found as above, the
usual way is to add one-half more for a test pressure, then
apply by hydraulic pressure as high as the test pressure, and,
if the boiler goes through this test all right, it is safe to
run it at two-thirds of test pressure.
Before putting hydraulic pressure on an old boiler, empty
the boiler, go over it carefully with the hammer for broken
braces, weak and corroded spots, figure for safe pressure on
the thinnest place found in boiler, fill boiler full of cold
water, and gradually heat it until the desired pressure is
reached. By this mode of testing by hot water pressure, the
heated water is expanded, and is more elastic than when cold,
and is not so liable to strain the boiler.
Before allowing the pressure to be applied, see that the
boiler is properly braced and stayed, and that the rivets are
of proper size.
All flat surfaces, such as found in fire-box boilers, should
have stays not over 5 or 6 inches apart, for all ordinary
pressure and boiler heads not over 7 inches apart.
On account of the loss of strength in the plates by rivet
holes, some authorities allow only 70 per cent, of the safe
pressure given above, for double-riveted boilers, and 56 per
cent, for single-riveted boilers:
EXAMPLE.
1 66 Tbs. safe pressure in first example x 70 per cent, for
double-rivets = 116.20 Ibs. safe pressure for double- riveted
boiler.
1 66 Ibs. safe pressure in first example X5& per cent, for
single-riveted seams =92.96 Ibs. safe pressure for single-
riveted boilers.
i63
SCALE IN BOILERS
Mr. T. T. Parker writes as follows to the Amerinm
Machinist :
If there is one thing more than another that the average
engineer is careful with, it is the use of boiler compounds.
With an open exhaust heater and an overworked boiler, and
using water from a drilled well sixty feet deep in limestone, I
have had to be rather careful to avoid scale and foaming.
I offer some notes from my experience under the above
conditions.
In using compounds containing sal soda, I had to use 40
per cent, more cylinder oil, and this invariably reacted,
through the heater and feed water, on the boiler, and pro-
duced foaming. I have used six compounds warranted to
cure foaming with above results. The compounds were
tannic acid and soda.
Changing to the use of crude oil, I found that the volatile
parts went over to the engine, and saved loper cent, cylinder
oil over when using nothing, and 50 per cent, over the use
of sal soda. There is a peculiar easy manner of making
steam that is very different from the same boiler using sal
soda. The results on scale are as follows :
In changing to a different solvent, the results for a few
runs were very good, and then it seemed to lose its virtue
while'losing double quantity ; result, foaming. With crude
oil used continually, I have had scale from one-eighth inch
thick, but never any thicker, as it came off clean, and was
very porous. I prefer oil to any acid or alkali solvent.
For cleaning a scaled boiler I would recommend alternate
use of oil and sal soda, but the remedy is heroic. If the
boiler is not clean in two weeks, I miss my guess. I have
tried kerosene, and found it too volatile to be of value in a
limestone district. In summing up the results, I believe :
First — With an open exhaust heater, use only the
best cylinder oil, which should be at least 80 per cent,
petroleum.
Second — If the crude oil does not keep the scale all
out, alternate one run with sal soda.
Now, I only offer this as my experience, knowing full
well that the conditions are never absolutely the same.
But I know of a plant (in this city) where the boiler is not
worked up to its full capacity, and which is kept entirely
free from scale, using hard water, by the alternate use of sal
goda and crude oil.
i64
FUTURE OF THE STEAM ENGINE.
The annual meeting of the British Association for the
Advancement of Science, lately held at Bath, England, was
opened by an address by Sir Frederick Bramwell, the pres-
ident of the association, in which he repeated a prediction
made by him at a former meet ing of the association regard-
ing Ihe displacement of the steam engine in the future. He
said it was a sad confession to have to make, that the very
best steam engines only utilized about one-sixth of the work
which resides in the fuel that is consumed, though at the
same time it is a satisfaction to know that great economical
progress had been made, and that the six pounds or seven
pounds of fuel per horse power per hour consumed by the
very best engines of Watts' days, when working with the
aid of condensation, is now brought down to about one-
fourth of this consumption. Continuing, he said: At the
York meeting of our association I ventured to predict that,
unless some substantial improvement were made in the steam
engine (of which improvement, as yet, we have no notion),
I believed its days for small powers were numbered, and that
those who attended the centenary of the British Association
in 1931, would see the present steam engines in museums,
treated as things to be respected, and of antiquarian interest,
by .he engineers of those days, such as tlie over-topped
steam cylinders of Newcomen and of Smeaton to our-
selves. I must say I see no reason, after the seven years
which have elapsed since the York meeting, to regret having
made that prophecy, or to desire to withdraw from it.
The working of heat engines, without the intervention of
the vapor of water by the combustion of the gases arising
from coal, or from coal and from water, is now not merely
an established fact, but a recognized and undoubted
commercially economical means of obtaining motive power.
Such engines, developing from I to 40 horse power, and
worked by ordinary gas supplied by gas mains, are in
most extensive use in printing works, hotels, clubs,
theatets, and even in large private houses, for the wrorking
of dynamos to supply electric light. Such engines are also
in use in factories, being sometimes driven by the gas
obtained from " culm " and steam, and are given forth a
horse-power for, it is stated, as small a consumption as one
pound of fuel per hour. It is hardly necessary to remind
you — but let me do it — that, although the saving of half a
pound of fuel per horse-power appears to be insignificant
when stated in that bald way, one realizes that it is of the
I6S
highest importance when that half-pound turns out to be
33 per cent, of the whole previous consumption of one of
those economical engines to which I have referred. But,
looking at the wonderful petroleum industry, arid at the
multifarious products which are obtained from the crude
material, is it too much to say that there is a future for
motor engines worked by the vapor of some of the more
highly volatile of these products — true vapor — not a gas,
but a condensable body capable of being worked over and
over again? Numbers of such engines, some of as much as
four horse-power, made by Mr. Yarrow, are now running,
and are apparently giving good results, certainly excellent
results as regards the compactness and lightness of the
machinery; for boat purposes ihey possess the great advan-
tage of being rapidly under way. I have seen one go to-
work within two minutes of the striking of the match to
light the burner. Again, as we know, the vapor of this
material has been used as a gas in gas engines, the motive
power having been obtained by direct combustion. Having
regard to these considerations, was I wrong in predicting
that the heat engine of the future will probably be one inde-
pendent of the vapor of water? And further, in these days
of electrical advancement, is it too much to hope for the
direct production of electricity from the combustion of fuel ?
GAS FOR LOCOMOTIVES.
The problem of obtaining a cheaper fuel than coal for
locomotives, which has long bothered railroad men, seems
likely to be solved soon by experiments now being made with
gds. A very good test of the new fuel has been made at the
works of the electric light company in West Chester, which,
since the fire that destroyed the old plant several months ago,
have been dependent for their motive power upon the Shaw
locomotive. This is the engine that made such a good record
in some trial trips two or three years ago, but which has never
done much road service.
Instead of coal, gns mixed with air has been used in the
locomotive with e.itire success in generating sufficient power
to drive the dynamos. With larger machines for producing
and mixing the gas, it is believed that power enough can be
obtained for driving locomotives with trains, and a special car
is now being built at New York to hold a large machine of
the kind used in mixing the gas, and thestorage receivers.
1 66
PROPORTIONS OF STEAM BOILERS.
In a recent communication to the Societe Scientifique
Industrielle of Marseilles, M. D. Stapfer remarked that, as
he had never met with any good practical rules for the pro-
portions of boilers for steam engines, he had taken the trou-
ble to examine a very large number of different types, which
were working satisfactorily, and from them had deduced the
following rules : The water level in the boilers of torpedo
boats was usually placed at two-thirds the diameter of the
shell, and in marine, portable and locomotive boilers at three-
fourths this diameter. The surface from which evaporation
took place should, however, be made greater as the steam
Eressure was reduced — that was to say, as the size of the
ubbles of steam became greater. To produce 100 Itxs. of
steam per hour, at atmospheric pressure, this surface should
not be less than 7.32 square ft., which may be reduced to
1.46 square ft. for steam at 75 Ibs. pressure, and 0.73 ft. for
steam at a pressure of 150 Ibs. It is for this reason that
triple-expansion engines can be worked with smaller boilers
than were required with engines using steam of lower pres-
sure. The amount of steam space to be permitted depends
upon the volume of the cylinder and the number of revolu-
tions made per minute. For ordinary engines it may be
made a hundred times as great as the average volume of
steam generated per second. The section through the tubes
may be one-sixth of the fire-grate area when the draught is
-due to chimney from 27 ft. to 33 ft. high, which in general
corresponds to a fuel consumption of 12.3 pounds of coal
per square foot of grate surface per hour. This area may
be reduced to one-tenth that of the grate when forced
draught is employed.
TESTING BOILER PLATES.
A good every-day shop plan of testing boiler plates is to cut
ftff a strip i# inches wide and of any convenient length.
Drill a quarter-inch hole, and enlarge it to three-quarters of
an inch by means of a drift-pin and hammer. If the plate
shows no signs of fracture, it may be considered of good
quality.
Another method is to cut off a narrow strip, heat it
to a cherry red and cool suddenly. Grip the piece in a vise,
and bend it back and forth at right angles by means of a
piece of gas pipe dropped over the end. The number of
times the piece can stand this bending is the measure of its
quality. A good piece of soft steel boiler-plate should s'and
twelve or fifteen bendings without showing fracture.
167
MANIPULATION OF NEW ENGINES.
After engines have been set up, they must be adjusted to
/heir work. It is not every man that can do this properly,
for it requires experience and consideration to determine
exactly what is to be done. A new engine is a raw machine,
so to speak, and, no matter how carefully the work has been
done upon it, it is not in the same condition that it will be
in a few weeks, or after the actual work it does has worn
its bearings smooth and true. In the best machine-work,
there are more or less asperities of surface, and very much
more friction than than there will be later on. Bearings and
boxes are not fitted under strain ; they are fitted as they
stand, independently in the shop, and this entails a condi-
tion of things which actual work may show to be faulty.
For this reason an engineer should not go at a new engine
hammer and tongs, and try to suppress at once every slight
noise or click that he may hear. Neither should he key up
solid, or screw down hard, the working shafts and bearings,
for the first few days. It is much better to let the things
run easily for a while, at the expense of a little noise, rather
than to risk cutting before the details get used to each other.
Many good engines have been disabled by too great zeal on
the part of those in charge, when a little forbearance would
have been much better. Pounding, caused by bad adjust-
ment, or valve setting, and pounding caused by new bear-
ings not in intimate relation with each other, are quite
different in character, and a careful engineer will not make
haste to decide upon the remedy until he has indicated and
investigated the engine, and found out exactly where the
trouble is. Not long ago we saw a new engine badly cut in
its guides from this very cause ; a slight jar was noticed, and
the engineer, arguing that the crosshead was the seat of the
noise, set out the gibs so much that they seized and plowed
some bad scores in the cast-iron guides, which will always
remain to remind him of his thoughtlessness. What has
been said above of the engine, is also true of the boiler and
its appurtenances. No new boiler should have pressure put
upon it at once. Instead, it should be heated up slowly for
the first day, and whether steam is wanted or not. Long
before all the joints are made, or the engine ready for steam,
the boiler should be set, and in working order. A slight fire
should be made and the water warmed up to about blood
heat only, and left to stand in that condition and cool off,
and absolute pressure should proceed by very slow stages.
Persons who set a boiler and then build a roaring fire under
i68
It, and get steam as soon as they can, need not be surprised
to find a great many leaks developed ; even if the boiler does
not actually and visibly leak, an enormous strain is need-
lessly put upon it which cannot fail to injure it. Of all the
forces engineers deal with, there are none more tremendous
than expansion and contraction.
TRIPLE EXPANSIONS.
An interesting example of the value of triple expansion
engines, as compared with compound, was exhibited on the
Clyde, on the trial of the Orient liner Cuzco, which has
recently been thoroughly renovated and furnished with new
boilers working to a pressure of 150 pounds to the square inch,
and with triple expansion engines of the most approved type,
The Cuzco is seventeen years old, and has hitherto been
regarded as a 12% knot boat. Recently she was tried on the
measured mile for a six-hours run, when she attained a speed
of 1 6 knots, and made upward of 75 revolutions per minute.
This increase in speed was, a daily newspaper correspondent
says, accompanied with the usual economy in coal consumption,
and the incident is remarkable on account of the success with
which the power of the new engines has developed a high
speed in a vessel, the model of which is comparatively
obsolete.
STEAM AS A CLEANSING AGENT.
For cleaning greasy machinery nothing can be found that
is more useful than steam. A steam hose attached to the
boiler can be made to do better work in a few minutes than
any one is able to do in hours of close application. The
principal advantages of steam are, that it will penetrate
where an instrument will not enter, and where anything else
would be ineffectual to accomplish the desired result.
Journal boxes with oil cellars will get filthy in time, and are
difficult to clean in the ordinary way ; but, if they can be
removed, or are in a favorable place, so that steam can be
used, it is a veritable play work to rid them of any adhering
cubslance. What is especially satisfactory in the use of
Steam, is that it does not add to the filth. Water and oil
spread the foul matter, and thus make an additional amount
of work.
1 69
POINTS FOR ENGINEERS.
When using a jet condenser, let the engine make three or
four revolutions before opening the injection valve, and
then open it gradually, letting the engine make several more
revolutions before it is opened to the full amount required.
Open the main stop valve before you start the fires un-
der the boilers.
When starting fires, don't forget to close the gauge-
cocks and safety-valve as soon as steam begins to form.
An old Turkish towel, cut in two lengthwise, is better
than cotton waste for cleaning brass work.
Always connect your steam valves in such a manner that
the valve closes against t^ie constant steam pressuie.
Turpentine, well mixed with black varnish, makes a good
coating for iron smoke pipes.
Ordinary lubricating oils are not suitable for use in pre-
venting rust.
You can make a hole through glass by covering it with a
thin coating of wax — by warming the glass and spreading
the wax on it, scrape off the wax where you want the hole,
and drop a little fluoric acid on the spot with a wire. The
acid will cut a hole through the glass, and you can shape
the hole with a copper wire covered with oil and rotten-
stone.
A mixture of one (i) ounce of sulphate of copper, one-
quarter (#) of an ounce of alum, half (y2) a teaspoonfitl of
powdered salt, one (i) gill of vinegar and twenty (20) drops
of nitric acid will make a hole in steel that is too hard to
cut or file easily. Also, if applied to steel and washed off
quickly, it will give the metal a beautiful frosted appear-
ance.
It is a fact that thirty-five cubic feet of sea water is equal in
weight to thirty-six feet of fresh water, the weight being one
ton (2,240 pounds).
Remember that coal loses from ten (10) to forty '(40) per-
centum of its evaporative power if exposed to the influence
of sunshine and rain.
Those who have had experience think that for lubricat-
ing_purposes palm nut oil cannot be surpassed, for the rea-
son that it does not gum or waste; neither does friction
remove it readily from the surfaces where it is applied, and
its use is exceedingly economical. The best cylinder oils
produce no better effect.
If you are obliged to make use of such a barbarism as a
rust joint, mix ten (10) parts by weight of iron filings, and
three (3) parts of chloride of lime .with enough water to
make a paste. Put the mixture between the pieces to be
joined, and bolt firmly together.
Too much bearing surface in a journal is sometimes worse
than too little.
Steel hardened in water loses in strength — but hardenii- •;
in oil increases its strength, and adds to its toughness.
RAILWAY GAUGES OF THE WORLU
jreland has a standard gauge of 5 ft. 3 in. ; Spain and
Portugal 5 ft. 6y% in. ; Sweden and Norway have the 4 ft
8/^ in. gauge over the majority of their railroads, but 20
per cent of the Swedish roads have other gauges, varying
from 2 feet 7^ in. up to 4 ft.
In Asia, of the British-Indian roads, about 7,450 miles
have a gauge of 5 ft. 5^ in., the remainder being divided
among six gauges from 2 ft. to 4 ft. Of the narrow gauges,
the most prevalent, embracing 4,200 miles, is the metre,
3 ft. 3% in. ,
In Japan, with the exception of an 8-mile piece begun in
1885, with a gauge of 2 ft 9 in., all the roads have a 3 ft.
6 in. gauge.
In Africa, the Egyptian railroads, amounting to 932 miles,
are of the 4 ft. 8^ in. gauge. Algiers and Tunis, with
1,203 miles in 1884, had the 4 ft. 8)4 i"- standard on
all but 155 miles, which had a 3 ft. 7^ in. gauge. The
English Cape Colony had, in 1885, 1,522 miles, all of 3 ft.
6 in. gauge.
In America, practically the whole of the United States
and Canadian railroads are of 4 ft. 8^ in. to 4 ft. 9 in.
gauge. In Mexico, in 1884, 2,083 miles were 4 ft. 8^ in.,
and 944 3 ft. gauge. In Brazil, at the end of 1884, there
were 869 miles of 5 ft. 3 in. gauge, and 4, 164 miles of various
gauges between 2 ft. and 7 in., over 3,700 miles being I
metre, or 3 ft. 3% in., or that this may be considered the
standard gauge of Brazil.
In Australia, the different colonies, rather singularly,
have different gauges, that of New South Wales being 4 ft.
8^ in., Victoria 5 ft. 3 in., South Australia 4 ft. 3 in. and 3
ft. 6 in., and the other colonies 3 ft. 6 in.
The total mileage in operation in the world at the end of
1885 was 303,048 miles. Of this length, 74 per cent, were
of the 4 ft. 8>£ in. to 4 ft. 9 in. standard, 12 per cent, had
larger gauges, and 14 j er cent, smaller.
MEASURES OF DIFFERENT COUNTRIES
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METRIC SYSTEM
172
THE MONETARY UNITS AND STANDARD COINS
OF FOREIGN COUNTRIES.
The first section of the act of March 3, 1873, provides
" that the value of foreign coin, as expressed in the money of
account of the United States, shall be that of the pure metal
of such coin of standard. value," and that " the value of the
standard coins in circulation of the various nations of the
world, shall be estimated annually by the director of the
mint, and be proclaimed on the first day of January by the
secretary of the treasury.
The estimates of values contained in the following table are
those made by the director of the mint, Jan. i, 1878.
Country.
Monetary
Unit.
Standard.
Value.
Argen Repub. . .
Peso fuerte. . . .
Gold
IX C. M.
I O O
Austria
Florin
Silver
O 4.C 7
Belgium . ...
Franc
Gold & Silver
O IQ 1
Bolivia . . .
Dollar
Gold £ Silver
£. *
O QO ?
Brazil
Milreis of 1000
British Amer . . .
Bogota
reis
Dollar
Peso
Gold. .
Gold
Gold
o 54 5
I O O
O Q6 C
Central Amer.. .
Chili
Dollar
Peso
Silver
Gold
o 91 8
O QI 2
Cuba
Peso
Gold
O Q2 5
Denmark .......
Crown
Gold
o 26 8
Ecuador
Dollar
O QI 8
Egypt .
Pound of 100
France
piasters ....
Franc
Gold
Gold £ Silver
4 97 4
O IQ 1
Gt Britain ....
Pound sterling
Gold . .
4. 86 ofc
Greece .
Drachma ....
Gold £ Silver
O IQ 1
German Emp . . .
India
Mark
Rupee, 1 6 an. .
Gold
Silver
o 23 8
o 43 6
Italv
Lira
Gold £ Silver
o 19 3
1 y
Japan
Liberia . . ......
Yen
Dollar
Gold
Gold
o 99 7
I O O
Mexico
Dollar....
Silver.... .. .
O QQ 8
Neitherlands . .
Florin
Silver
Norway . 0 ...
Crown
Gold
o 26 8
Paraguay ......
Peso
Gold
I O O
Feru . ,
Sol
Silver..
o 06 o
'I UK MONETARY UNITS— Continued.
Country.
Monetary
Umts.
Standard.
Value.
Gold
O 02 5
Portugal
R ussia
Mil. looo r's . .
Rubles, 100 co
Gold
I 80
O77 4.
Sandwich Islands
Dollar
Gold
I O O
%iin . .
Peseta of 100
Sweden
Switzerland ....
Tripoli
centimes . . .
Crown
Franc
Mah. 20 v»''s
Gold& Sil-cr
Gold........
Gold & Silver
Silver
o 19 3
o 26 8
o 19 3
o 82 9.
Tunis
Pi's 16 car
Silver . ...
o ii 8
Turkey
Piaster ..-...,
Gold..
043
Colombia . .
Peso
Silver
o 91 8
Uruguay
Pat aeon ......
Gold..
o 94 9
DIMENSIONS OF AMERICAN ENSIGNS.
Numbers.
Head or
hoist.
Whole
length.
Length of
union.
Feet.
Feet.
Feet.
I
19.00
36.00
14.40
2
16.90
32.00
12.80
3
14.80
28.00
1 1. 20
4
13.20
25.00
10.00
5
1 1. 60
22.00
8.80
6
IO.OO
19.00
7.60
I
8.45
7.40
16 oo
14.00
'!:£
9
.12.00
4.80
10
5.20
IO.OO
4.00
ii
4.20
8.00
3.20
12
3.7o
7.00
2.80
13
3.20
6.00
2.40
14
2.50
5.00
2.OO
TO DETECT IRON FROM STEEL TOOLS.
It is diffiult to distinguish between iron and steel tools.
They have the same polish and workmanship ; use will com-
monly show the difference. To make the distinction quickly,
place the tool upon a stone, and drop upon it some diluted nitric
acid, four parts of water to one of acid. If the tool remains
clean, it is of iron; if of steel, it will show a black spot where
touched with the acid. These spots can be easily rubbed off
174
ARTIFICIAL ICE-MAKING.
Reduced to the fewest words, the scientific principle under-
lying all methods for making artificial ice is that whenever
a liquid is evaporated it takes up more or less heat from sur-
rounding objects. This fact can be easily demonstrated by
any one. Stick your finger in your mouth and moisten it
with saliva. Then hold the wet finger in the wind. At once
that finger feels colder than the rest, for the moving air
takes up or evaporates the moisture, and the skin gives up
some of its heat. It is an old scientific trick to freeze water
in a fire by wrapping the bottle with a rag soaked in ether or
chloroform. The heat of the fire evaporates the highly vola-
tile ether so quickly that the etlicr sucks all of the heat out
of the water and freezes it. This is practically what the ice
maker does, only he uses ammonia or sulphurous oxide in-
stead of ether, and works on a large scale with large pumps,
engines and miles of iron pipe.
175
At ordinary temperature, ammonia is a vapor or gas. The
common ammonia sold in drug stores is really ammonia
water made by saturating water with ammonia gas. The
ammonia commonly used in ice-making is anhydrous am-
monia, which is liquid ammonia without any water in it.
There are many kinds of ice-making machines made, but all
practically work on the same principle.
The principal part of the plant is the compressor pump.
Then follows the condenser, the expansion coils and the re-
ceiver. The anhydrous ammonia is received by the ice-
maker in oblong iron drums containing 100 pounds or more,
and it is fed into the pump through a small pipe to the suc-
tion valve at the lower end of the pump, whether it be single
or double acting. The pump performs a double office, for
with one stroke of the piston it sucks in the anhydrous am-
monia, and on the return stroke compresses the gas to a
liquid, for the anhydrous ammonia is used over and over
again, first as liquid, then as an expanding gas freezing the
liquid, and then back as a liquid again. The ammonia gas
is liquified not only by pressure but by cold. The pump
forces the gas into the condenser first. This is a series of
coils of small pipe over which cold water is constantly flow-
ing. The gas pressed into the smaller pipes is condensed to
liquid ammonia. As it condenses, the liquid ammonia flows
into a storage tank through small pipes leading from the
condenser. The pressure from the pump and suitable check
valves force the liquid ammonia from the storage tank,
which lies in a horizontal position, into two large vertical
cylinders, and from them into the expansion coils which lie
in the bottom of the freezing tanks.
Th*3 pipes of the expansion coil are much larger than the
pipes in the condenser, and here the liquid ammonia expands
or turns to vapor again, and as it evaporates it takes the
heat from the salt brine in the tank and reduces its tempera-
ture from 18 o above to 10 o below zero, depending on the
flow of the gas. The compressor pump, by forcing the liquid
ammonia from it and sucking the gas towards it, keeps the
anhydrous ammonia moving along constantly, and it goes
into the receiver, from which it is pumped to be compressed
and chilled into a liquid again.
The ice factories which use sulphurous oxide instead of
anhydrous ammonia have a brine made from magnesium
chloride instead of common salt, but in other respects the
176
system is about the same. The anhydrous ammonia and
sulphurous oxide processes are called the compression
system. In the absorption system the liquid is first heated
in a boiler and "the vapor which is generated is made up of
about 9 parts of ammonia gas and 1 part of steam. This
vapor first passes through a condenser, where tte steam Is
turned into water again, but as the temperature is not low
enough to liquify the ammonia gas, it is forced along by the
boiler pressure to another condenser. Here the gas is con-
densed to a liquid, and then passes on to the expansion coils
just as it does in the compression system. After doing its
work, the gas is brought back to the "absorber," where it is
taken up by water again and pumped back into the boiler.
In making artificial ice, the manufacturer wants pure
water. To be certain that the water is free from sedimeni
and typhoid germs, he filters and distils the water before it
is frozen. In some ice works the water is filtered once before
it is distilled, and twice afterwards. The freezing tanks are
made of iron. They usually are set below the floor for the
purpose of facilitating the handling of ice. The average
tank is about 50 feet long, 20 feet wide and 4 feet deep. The
cans in which tne distilled water is frozen are 44 inches by
22 inches by 11 inches in size.
ft The pipes which carry the anhydrous ammonia go back
and forth across the tank between the cans, and the salt
water brine is kept in motion by an agitator something like
a screw propeller. This gives the brine an even tempera-
ture. It requires from 34 to 60 hours to freeze a 300- pound
cake of ice. Over the freezing tank is a traveling crane with
a block and tackle for hoisting the cans with the frozen
blocks out of the tank. The cans are lifted, so that when
clear of the tank they tilt upside down. Streams of tepid
water are directed on the can, and in a short time the cake
of ice slips out of the can and slides down the gangway to
the ice-house.
Nearly every brewery in the country has its own refriger-
ating plant. For cooling cellars, vaults and other parts of
the brewery, chilled brine is pumped through pipes. Some-
times, however, as in the direct expansion method, the ex-
pansion pipes are used. Both methods are also employed in
chemical works, cold storage warehouses and packing
houses. Ice machines are rated with capacities varying from
50 to 100 tons of ice a day. They are built vertical and hori-
177
zontal, single or duplicate, operated either direct or from
an engine.
NOVEL USES OF COMPRESSED AIR.
Most people think that compressed air is only used for
automatic car-brakes and rock drills. The fact is, com-
pressed air as an agent for transmitting energy and power
is pushing electricity hard and, on some lines, has distanced
steam.
On many railroads compressed air has taken the place o(
whisk brooms and beaters for cleaning seat cushions of pas-
senger cars. The air at 50 to 75 pounds pressure to the
square inch is brought into the car through an air hose
which has. a brass air nozzle on the end. The women handle
this nozzle as though water instead of compressed air were
coming through, and the air jet drives the dust, cinders and
dirt out of the cushions quicker and better than any other
method.
In the new criminal court building of Chicago, a system of
pneumatic clocks has been installed. The "master" clock
sends pulsations of compressed air through small pipes to :
the connecting clocks, and thus all run on the same time uiv1
are regulated together.
In several machine shops in the country there is not a belt
or a piece of shafting outside of the engine-room. Instead,
pipes run from the compressed air reservoir to compressed
air motors. Each drill, lathe, reamer, milling machine,
emery wheel, bending rolls, punch, drop hammer and press
has its individual air motor or engine, and the mere turning
of a throttle valve starts or stops the machine.
The pneumatic clock system was installed first in Paris
about 1870. From it grew the present compressed air cen-
tral-power system, which supplies over 10,000 horse-power
to users in the French capital. It is there used for all pur-
poses, from running clocks to operating dynamos for elec-
tric lights. The central station furnishes air at a pressure
of 75 pounds to the square inch.
Asphalt used for street-paving is refined by compressed air.
In its original shape, just as it comes from Trinidad, asphalt
is too soft for street-paving, and is not homogeneous To
refine it, the asphalt is boiled in kettles for three or four
days, and while the heat is on it must be stirred. Pipes hav-
178
ing numerous holes are placed in the bottom of the kettle,
and while the asphalt is boiling, compressed air is forced
through the pipes and, escaping through the holes, agitates
the thick black material, thus refining it.
Compressed air was the paint-brush which placed the color
on the World's Fair buildings in Chicago, and which to-day
is painting railroad bridges and corrugated iron plates for
buildings. The compressed air not only draws the liquid
paint from the tubs or buckets, but sprays it over the sur-
face and drives it into the wood.
In the big shipyards, where the government vessels are
built, all the calking is done by compressed air. and one com-
pressed air calking machine does the work of four men.
TLis calker strikes 1.000 blo\vs a minute. The same tool is
used by boiler-makers, and. in a modified form, by stone-
cutters for dressing an i carving stone. The little engine
which does the work is in the handle of the tool which is
about the size of a larne chisel handle. Tiie air is brought
to the tool by a small rubber pipe, which is so flexible it can
be handled easily and at any angle. A piston and spring
shove the tool in and out, and it can be so adjusted that the
heaviest or most delicate work can be done with it.
* Acids which would eat a pump up at once, are raised by
compressed air. Sewage which is below the level of the
sewer is forced up by compressed air. Impure water is
cleaned, gold and silver are dug from mines, letters are
copied in the letter press, elevator signal bells are rung,
cattle are lifted after being killed in slaughter houses, fur-
nace grates are shaken, crude oil is atomized under steam
boilers, grain is cleaned, and a hundred other things are
daily done by compressed air.
CONCERNING ELECTRIC BATTERIES.
In a general way batteries are divided into two classes-
open circuit batteries and closed circuit batteries. In all
kinds of batteries the electro-motive force decreases and the
internal resistance increases when working on a circuit of
low resistance. This is caused by "polarization," which is
the collecting of tiny bubbles of hydrogen gas on the nega-
tive plate due to the action of the current. These bubbles
covering the negative plate not only diminish the working
surface of the plate, and thus reduces the electro-motive
179
f.>rce. but increases the re>ist,ince. In this condition the
battery is said to be polarized. To correct this evil various
chemicals, either fluid or solid are placed in the battery to
generate oxygen which may unite with the hydrogen. Such
chemicals are called "depolarizers."' Those batteries in
which the depolarizers act slowly and after the buttery has
stopped work are called "open circuit1': that in which the
depolarizers is working is "closed circuit." The open circuit
battery is used where the demand for the current is inter-
mittant: the "closed circuit battery" is used where the cur-
rent is required almost continuously.
Batteries should be kept where the temperature is about
even, avoiding extremes of heat or cold. They should be
carefully protected from dust and dirt. The cells should be
covered so as to prevent rapid evaporation of the solution.
The best place for batteries is a dry cool place.
\Vhere zinc is used in a battery the plate should be rolled
and not cast zinc. The carbon plates should be solid, fine
and hard. Those made from gas-retort carbon. The upper
part of carbon rods should be dipped in melted paraffiine
until the wax has soaked in, say to an inch or so from the
top. This will keep the solution from "creeping" or crawl-
ing up, as it will do unless the rod is waxed. Before a zinc
rod is placed in a battery it should first be thoroughly
brightened by scouring it with weak sulphuric acid, and then
a small portion of mercury should be rubbed over it. The
amalgamation will prevent what is known as "local action."
Sal-ammoniac, if used, should be pure, otherwise the battery
will become dirty. Porus cups should be soaked in water
and then thoroughly scrubbed out. Carbon plates, in renew-
ing batteries, should be treated in the same way. Batteries
should never be neglected if good work from them is desired.
A poor battery is often worse than no battery at all, and it is
false economy to re-charge with impure and therefore cheap
chemicals.
HOW BOILER PLATES ARE PROVED.
This is done by placing a piece of Bessmer steel 10 inches
long in a testing machine. Gradually the surface scales off
in the middle, to become smaller in area, and somewhat
elongated, til. at last, it breaks with a sharp snap at a break-
ing strain of about 28 tons to the square inch, the reduction
of area bein«r 51 per cent, and the elongation 23 per cent.
i So
DIFFERENCES OF TIME FROM NEW YORK.
At any Given Time hi New York it is in
HKS. MIN. SKC.
Amsterdam (Holland) 5 16 later.
Berne (Switzerland) 5 26
Berlin ( Prussia) 5 49 * - "
Brusses (Belgium). ... 5 13 30 u
Buda Pesth (Hungary) 6 12
Carlsruhe ( Baden) 5 30
Qhristiania (Norway) 5 39
Cologne (Germany) 5 2 j.
Constantinople (Turkey) 6 52
Copenhagen (Denmark) 5 46
Dublin (Ireland) 4 30 30 "
Frankfort (Germany) 5 30
Geneva (Switzerland) 5 23 30 "
Gothenburg (Sweden) 5 45
Greenwich (England) 4 56
Hamburg (Germany) 5 36
Lisbon (Portugal) , .... . .. .... 4 19 30 '•
London (England) 4 5 > 5^ *"
Madrid (Spain) 4 41 15 u
Moscow (Russia) 7 26 "
M unich ( Bavaria) 5 42 30 "
Naples (Italy) ?, . . . 5 53
Paris (P>ance) 5 05 15 "
Prague (Austria) 5 54 "
Rome (Italy) 5 46 "
St. Petersburg ( Russia) 6 57 "
Stuttgart ( Witrtemberg) . , 5 33 "
Stockholm (Sweden) 6 08 "
Trieste (Austria) 5 51
Venice (Italy) 5 45 30 "
Vienna (Austria 6 01 33 "
Warsaw (Poland) 6 20 ' "
The differences are at the rate of one hour for every
fifteen degrees of longitude, or four minutes for each degree.
A VALUABLE PRESERVATIVE PAINT.
Soapstone incorporated with oil, after the manner of paint,
is said to be superior to any kind of a paint as a preservative.
Soapstone is to be had in an exceedingly fine powder, mixes
readily with prepared oils for paint, which covers well surfaces
of iron, steel, or stone, and is an effectual remedy against
rust.
TIME AT DIFFERENT PLACES, WHEN IT IS
O'CLOCK AT NEW YORK CITY; ALSO, DIF-
FERENCE IX TIME FROM NEW YORK.
New York City 12 M.
Fast.
Slow.
Places.
II
12
II
12
II
12
12
II
I I
II
I I
II
II
12
II
12
12
II
12
II
12
II
10
II
4
ii
12
10
II
12
12
12
12
10
II
II
IO
MS
p.m
a. m.
}.m
a.m.
p.m
a.m.
p.m
a.m.
p.m
a.m.
p.m
a.m.
p.m
a.m.
a. m.
«
p.m
a.m.
p.m
a. m.
«
p.m
«
u
a.m.
! «
11
M
.:
„
u
IO
28
II
41
5
43
10
5
i
12
4
S
II
M
9
10
'9
23
54
4i
3i
36
36
42
u
3i
22
41
46
4
55
4
20
9
27
56
27
40
42
£
24
12
10
40
20
10
56
12
3*
37
16
H
56
Albany, N. Y
Annapolis, Mel
1 l
5° 4
1 6 40
4933
20 52
ii 46
4020
36 18
529
18 2
2836
23 4»
10; 4
2350
28l6
I132
I7|20
4i:33
48 '40
5 r7
2850
37 4
1848
4356
H
1044
5528
423
536
148
1218
418
56|
3944
5046
32 4
4
I
40
52
46
if
32
33
i7
$(
44
36
48
ft
18
i
i
i
1:
Augusta, Me
Baltimore Md
Buffa'o, NY
Charleston S. C
Chicago, 111
Cleveland, O.. . .
Detroit, Mich-
Fall River, Mass
Frankfort, Ky
Halifax, N. S
Harrisburg, Pa
Hartford, Conn
Key West, Fla
Leavenworth, Kan
Liverpool, Eng.
Lowell j^lass
Milwaukee, Wis
Montpelier, Yt
Montreal, Que..
New Bedford, Mass
New Haven, Conn
New Orleans, La
Niagara Falls, N. Y.
Norfolk, Ya
Omaha, Neb
1 82
TIME AT DIFFERENT PEACES.— Continued.
New York City 12 M.
I
II
"as
M
t.
S
S
II
lo\\
M
10
4
4
24
*9
13
9
32
13
28
8
21
' 2
12
S
Places.
II
M
s
u
5
ii
9
u
12
12
12
II
II
8
9
8
1 1
12
10
II
II
II
II
49
5
55
56
35
15
10
ii
40
46
50
27
46
3i
5
54
5i
38
57
A7
36
21
20
52
2
25
II
48
10
9
36
13
39
37
59
12
27
24
/|8
«
]). m
a. m .
p. in
C(
a.m.
u
p. m
a m.
5
5
15
10
ii
5
21
2
25
II
37
2
3
2
3
I
24
40
8
12
50
51
24
47
21
I
48
33
36
12
Paris, France
Philadelphia, Pa
Pike's Peak, Col
?ittsburg, Pa
Portland, Me
Providence, R. I
Quebec, Oue
Raleigh, N. C
Richmond, Va
Salt Lake City, Utah. . . .
San Francisco, Cal
Savannah, Ga. .
St. Loui-, Mo.
Syracuse, N. Y..
Toronto, Ont. . .
Trenton, N. J
Washington, D. C.. .
4.ENGTII AND NUMBER OF TACKS TO THE
POUND.
Title.
Length.
No. p. Ib.
Title.
Length.
No. p. Ib.
I oz.
Y* in-
16,000
10 OZ.
11-16
1, 600
1/2 "
3-i6 '
10,666
12 '
¥
^333
2 "
X '
8,000
14 *
13-16
I»i43
?.y* "
5-i6 '
6,400
16 <
H
1,000
6 "
X '
5>333
.18 «
15-16
888
4
7-16 '
4,000
20 '
I
800
6 "
9-16 '
2,666
22 '
11-16
727
8 "
% '
2,000
24 '
i>*
666
SWITCHING FROM THE ENGINE CAB.
A device that will enable the engineer, from his cab, to
switch his locomotive at pleasure, while the conductor on
the caboose or rear car closes the switch again, would surely
be a novelty in railroading, amounting to a revolution. Yet
a Cleveland inventor claims to have solved the problem, and
to be able to demonstrate its practicability with a working
model. Not to go into the details, it may be sufficient to
say that the " central throw " switch is shifted by a double-
flanged shoe, of any length, dropped from beneath any front
or rear truck, while the train is in motion, first overthrowing
the crank that draws the lock-plate off the fixed rail, then
moving the lug of the angle connected with the fly-rail to the
right or left, as indicated by the target on the engine or
caboose, after which the lock slides forward and grasps the
fixed rail, holding the " fly " in alignment, making a continuous
rail. Thus, a switch is carelessly left open, ai.d a passenger
train is approaching. The engineer detects the danger ; the
improvised " shoe " is dropped to the rail ; it strikes the lug,
the switch is closed, and, a collision avoided. On the other
hand, a train may be side-tracked by the same simple
operation from the cab. Of course, this would do away with
switchmen and frog accidents, and a great many other disad-
vantages incident to the present method, should the invention
come into practical use. This, necessarily is yet to be dem-
onstrated by actual test, under varying conditions, before
success can be confidently claimed ; but the device is certainly
of general interest.
RAILROAD SIGNALS.
The following signals, taken from the " Standard Code,"
are in use on a majority of American railroads. Explanation:
O means short, quick sound; — means long sound.
Apply brakes, stop O
Release brakes O O
Back O O O
Highway crossing signal — . — O, or O O
Approaching stations — blast lasting five C3&
Call for switchman O O O O
Cattle on track ^~~-
Train has parted — O
For fuel O O O Op
Bridge or tunnel warning a * O O — •
Fire aiarm c , — O O 0 3
Will take side track. . — — , ,
184
MANILLA KOPE TRANSMISSION.
A four-strand, hard-laid manilla rope, having a core, or
"heart-yarn," is probably the best rope for transmission pur-
poses, although three-strand rope is generally recommended,
says a writer in the American Miller. Of course it is im-
portant to have the rope, laid in tallow, as that greatly pro-
longs its life. The matter of splice is also important. Sea-
men all agree that the long splice is the best, but the expe-
rience of rope-transmission men is almost universally in
favor of a short splice. The length of a long splice in an
inch diameter rope will be five or si x feet, while a short one
is two and two and a half feet. I think this is what the
sailors term "a short splice." I have seen a short splice suc-
ceed where long ones have repeatedly failed. I have known
of a manilla rope used out of doors being painted with oil,
and then varnished. It seems to work well. Tar is certainly
unsuitable as a dressing for transmission rope. In the first
place it weakens it; in the second, its sticking to the pulley
or sheave would be a detriment rather than an improvement.
There is no difficulty about the ropes sticking on the sheave,
if properly designed and constructed.
SAFE WORKING PRESSURE FURNACE FLUES.
In a report to his company, the chief engineer of the
Engine, Boiler and Employers' Liability Insurance Company,
purposes the following rule for the safe-working pressure for
cylindrical furnaces in fines : Safe-working pressure
50/2 d
where
/=thickness of plate in thirty-second of au inck.
/=length of flue in feet.
//=diameter in inches.
RIVETLESS STEEL SLEEPERS.
^Mr. H.« Hipkins has invented a rivetless steel sleeper for
railroads. The lips or jaws for holding the rails in place are
stamped out of the solid plate, and are stiffened by corruga-
tions or brackets, which are also raised from the solid plate
out of the hollow at the back of each jaw. A center strip
is provided for the rail to rest upon, dispensing with all rivets
and loose parts. These sleepers can be laid rapidly, and they
are claimed to be especially adapted to use underground in
mines
TAKE CARE OF YOUR AUTOMATIC SPRINK-
LERS.
Ma"}* business blocks, workshops, stores, etc., have been
expensively fitted up with automatic sprinklers as a safeguard
against fires, a certain temperature of heat fusing the metal,
opening a valve and letting on a flow of water. But an in-
spection of th3 perforated pipes in a majority of instances will
reveal the fact that the apparatus has been neglected. Cob-
webs and dust cover the pipes, the sprinklers have been per-
mitted to corrode and unsolder, and, should a fire chance to
occur and the friendly services of the sprinklers ever be
required, they would l.e found almost useless, and for all the
work they would perform in the line of throwing cold water
on the devouring elements, the premises might as well have
remained l< unprotected. "
HOW TO OVERCOME VIBRATION.
How to put the smith shop in an upper story without
having the working on the anvils jar the building, has been a
problem that has frequently given manufacturers trouble. A
mechanical engineer says it may be safely done by placing a
good heavy foundation of sheet lead on the floor, and on that
putting a good thickness of rubber belting.
Another person who is interested in the problem has tried
the experiment, with some success, of placing the block, not
on the floor, but on the joist direct, making a cement floor up
to the block, and over the wooden floor, reaching back beyond
the reach of sparks. It is sometimes said that blacksmith
shops never burn, but they keep right on burning in spite of
theory, and cement floors ought to be helpful in guarding
against fires.
BOILER EXPLOSIONS IN GERMANY.
In Germany, during 1887, there were thirteen boiler
explosions, the Germans making up in destructiveness what
they lack in numbers of these accidents.
By the thirteen explosions, seventeen persons were killed;
five seriously, and fifty-nine slightly injured. One of these
explosions was, so far as known, the most destructive that
ever occurred. A battery of twenty-two boilers, at the blast
furnaces of Friedenshutte, Silesia, exploded, completely
demolishing the boiler-house, setting fire to a number of
other houses by throwing red-hot bricks, killing ten persons,
and wounding fifty-two.
i86
ALLOYS AND SOLDERS.
ALLOYS.
H
1)
a.
a,
o
U
G
N
Antimony.
-i
V
Bismuth. 1
Brass enjjine bearmfs
13
15
25
112
100
1 60
14
15
5
Tough brass, engine work. . . .
" for heavy bearings ....
Yellow brass for turning.
Bell metal
16
i
i
Brass locomotive bearings. . . .
" for straps and glands. .
Munt/'s sheathing
7
F')
64
I }O
6
i
i
4
........
Metal t •') expand in cooling. . .
2
9 1
i
9°
I
5
2
3
7
1 l<
. . • •
::::
Statuary bronze
2
Type m^tal from
" to
j
SOLDERS,
For lead
" tin
2
2
I
^
i
i
3
" " (hard)
" " (soft)
I
2
« u a
I
HOW TO MAKE HARD AND DUCTILE BRASS
CASTINGS.
Two per cent, by weight of finely pounded bottle glass,
placed at the bottom of the crucible in which red brass is
being melted for castings, gives great hardness, and at the
same time ductility to the metal. Porous castings are said to
be almost an impossibility when this is done, and the product
is likely tc V of great service in parts of machinery subject to
strain. An addition of one per cent, of oxide of manganese
facilitates working in the lathe and elsewhere where great
hardness might be an objection.
1*7
DECIMAL EQUIVALENTS
of 8ths, i6ths, 32ds and 64ths of an
Inch.
tractions Decimals
Fractions Decimals
of an of an
of an of an
Inch. Inch.
Inch. Inch.
1-64 = .015625
33-64= .515625
1-32 = .03125
3-64 = .046875
17-3 =03125
35-64 = .546875
1-16 = .0625
9-16 = .5625
5-64 = .078125
37-64 =0/8125
3-32 = .09375
19-32 = -59375
7-64= -109375
39-64 = .609375
# = .125
H = .625
9-64 = .140625
41-64 = .640625
5-32 = .15625
11-64= .171875
21-32 = .65625
43-64= -671875
3-16= .1875
11-16 = .6875
13-64= .203125
45-64 V. -703*25
7-32 =.21875
23-32 = .7185
15-64 = .234375
47-64 =.734375
X = -5
^ = •75
17-64 = .265625
49-64= .765625
9-32 = .28125
19-64 = .296875
25-32 = -78125
51-64= .796875
5-16 =.3125
13-16 = .8125
21-64 — -328125
53-64= .828125
1 1-32 = .34375
27-32 = .84375
23-64 = .359375
55-64 = .859375
H = -375
% = -875
25-64= • 390625
57-64 = .89625
13-32 = .40625
29-32 = .90625
27-64 = .421895
59-64= .921871
7-16 = .4375
15-16 = .9375
29-64= .453*25
61-64 = .953125
15-32 = .46875
31-64= .484375
X = -5
31-32= .96875
63-64 = -984375
HOW TO ANNEAL SMALL TOOLS.
A very good way to anneal a small piece of tool steel is to
heat it up in a forge as slowly as possible, and then take two
fireboards and lay the hot steel between them and screw them
in a vice. As the steel is hot, it sinks into the pieces of
wood, and is firmly imbedded in an almost air-tight charcoal
bed, and when taken out .cold will be found to be nice and
soft. To repeat this will make it as soft as could be wished.
1 88
AN EXPERIMENT WITH A LOCOMOTIVE.
A locomotive engineer who takes an intelligent interest
in operating his engine economically, relates the particulars
of runs where careful efforts were made to test the differ-
ence in the consumption of coal that resulted with the re-
verse lever hooked back as far as practicable and the throttle
full open, and running with a late cut-off, and the steam
throttled, or the difference between throttling and cutting off
short.
First Case — A train of 19 loaded and 12 empty cars,
rated at 25 loads. Run from Mansfield to Lodge, distance,
8.6miles, nearly level. Forced the train into speed, and then
pulled the reverse lever to the center notch, and opened the
throttle wide. The engine jarred a good deal, due, doubtless,
to the excessive compression, but the speed was maintained.
Twenty-two minutes were occupied by the run, a speed of
23 miles per hour, and 17 shovelfuls of coal M'eie con-
sumed in keeping up steam. By weighing, it was found a
shovelful averaged 14 pounds, making the coal used per
train mile average 27.7 pounds.
Second Case — A train of 25 loads and six empties, rated
as 28 loaded cars. Ran, as in the first case, from Mansfield
to Lodge. Pulled the train into speed in as nearly as possi-
ble the same time as in the previous test, but, when the
speed was attained, kept the reverse lever in the nine-inch
notch, and throttled the steam to keep down the speed.
Although the train was rated two loads heavier than the pre-
vious one, it consisted mostly of merchandise, while the
other was heavy freight, and handled decidedly easier. Hav-
ing pulled both trains over 40 miles before arriving at Mans-
field, there was full means of judging which was the easier
train to handle.
The run was made in 24 minutes, two minutes longer
than in the other case, and 32 shovelfuls of coal were used,
being at the rate of 52 pounds per train mile. In both
instances the fire was as nearly as possible the same depth at
the beginning and end of the run.
Our correspondent thus concludes his narrative: " It is
interesting to know that on the first occasion 238 pounds of
coal were used to do the same work in less time than 448
pounds were required to do under the changed circumstances
of the second trip; showing that a gain of 88 per cent, may
be effected by running with full throttle and early cut off."'
1 89
FAST AMERICAN STEAMERS.
The following is a list of twenty-eight fast American
steamers of from 2,200 to 4,000 tons, all of which have
shown a sea speed of more than fifteen knots for six consecu-
tive hours, and from which would be made the selection of
vessels to be held in reserve for cruisers:
Vessels. Hailing Port. Tonnage. Speed.
Newport New York 2,735 17-9
City of Augusta Savannah .2,870 16.5
City of Puebla New York .2,624 16.5
Queen of the Pacific. . . .Portland, Or 2,728 16.5
Alameda .Philadelphia 3,158 16.5
Mariposa San Francisco 3*158 16.5
State of California San Francisco 2,266 16
Alliance New York 2,985 16
Louisiana New York .. . . , 2,840 16
Ohio Philadelphia 3,126 15.6
Saratoga New York 2,426 15.4
City of Alexandria New York 2,480 15.4
Nacoochee Savannah 2,680 15.4
Chattahoochee New York 2,676 15.4
Roanoke ... , New York 2,354 15.4
Excelsior. New York 3,264 15.4
Alamo New York 2,943 15.4
Lampasas New York 2,943 15.4
SlPaso New York 3,531 15.4
El Dorado San Francisco .... .3,531 15-4
H. F. Dimock Boston .2,625 15.4
Herman Winter Boston 2,625 15.4
Seminole New York 2,557 15.4
El Monte New York 3,53* J5-4
San Pedro New York 3, 119 15.4
San Pablo New York. 4,064 15.4
Cherokee New York 2,557 15
Santa Rosa New York. -.2,417 "*>
A WARNING TO ENGINEERS.
. Never take the cap off a bearing and remove the upper
brass to see if things are working well, for you never can
replace the brass exactly in its former position, and you will
find that the bearing will heat soon afterward, on account
of your unnecessary interference. If there is any trouble,
you will find it out coon enough.
190
WEIGHT AND AREAS OF
SQUARt & ROUND BARS OF WROUGHTIRON
And Circumference of Round Bars.
One cubic foot weighing 480 Ibs.
i
Thickaesa
Weight of
Weight of
irea of
irea of
CirflUnftlWH
r Diameter
CD Baj
O B«
CD B«
O Bar
of Q Btf
IQ laches.
Oaa Foot long.
On9 Foot long
;n sq inches.
m sq. inahea.
miaehes.
O
.013
.010
.OO39
.0031
.1963
1,
.052
.041
.0156
.O123
.3927
ft
.117
.092
.0352
.0276
.5890
}
.208
.164
.0625
.0491
.7864
ft
.326
.256
.0977
.O767
.9817
.469
.368
.1406
.11O4
1.1781
A
.638
.501
.1914
.15O3
1.3744
*
.833
.654
.2500
.1963
1.5708
A
1.056
.828
.3164
.2485
1.7671
t
1.3O2
1.O23
.39O6
.3O68
1 9635
fi
1.576
1.237
.4727
.3712
2 1598
1
1.875
1 473
.6625
.4418
2 3662
if
2.2O1
1.728
.6602
.5185
2 6625
2.552
2.0O4
.7656
.6013
2.7489
U
2.93O
2.3O1
.8789
.6903
2.9452
1
3.333
2.618
1.0000
.7854
3.1416
A
3.763
2.955
1.1289
.8866
33379
i
4.219
3.313
1.2656 .9940
36343
A
4.7O1
3.692
1.4102
1 1075
373O6
i
5.208
4.091
1.5625
1.2272
3.9270
A
5.742
4.510
1 7227
1 3530
4 1233
i
6.302
4.950
1.8906
1 4849
43197
A
6.888
5.410
&OQ64
1.6230
4.5160
i
7.500
5.89O
2.2600
1 7671
4 7124
8.138
6.392
2.4414
1.9175
4.9O87
¥
8.802
6.913
2.64O6
2.0739
5.1051
H
9.492
7.455
2.8477
2.2365
6.3O14
i '
10.21
8.018
3.0625
24053
6.4978
H
1O.95
8.601 -
3.2852
2.5802
5.6941
11.72
9.2O4
3.5156
2.7612
5.89O5
H
12.51
9.828
3.7539
2.9483
,6.0868
SQUARE AND ROUND BARS.
(CONTINUED.)
Ttttknea
v Diameter
in Inches,
Weight of
QBar
One Foot long.
Weight of
O *"
One Foot long.
ire* of
in sq. inches.
ire* of
O B»
in sq. inchea
3.1416
3.341O
3.5466
3.7583
GrcnmfannM
in inches.
2
!
13.33
14.18
15.05
15.95
10.*47
11.14
11.82
12.63
4.0000
4.2539
4.5156
4.7852
6.2832
6.4795
6.6759
6.8722
|
j*
16.88
17.83
18.80
<L9.8O
13.25
14.OO
14.77
16.55
6.O625
6.3477
5.64O6
6.9414
3.9761
4.2OOO
4.4301
4.6664
7.0686
7.2649
7.4613
7.6578
it
2O.83
21.89
22.97
24.08
16.36
17.19
18.O4
18.91
6.250O
6.5664
6.89O6
7.2227
4.9O87
6.1672
5.4119
5.6727
7.854O
8.O5O3
8.2467
8.4430
I
25.21
26.37
27.65
28.76
19.8O
20.71
21.64
22.69
7.6625
7.9102
8.2656
8.6289
5.9396
6.2126
6.4918
6.7771
8.6384
8.8357
9.O321
9.2284
3
!
30.00
31.26
32.65
33.87
23.66
24.65
25.67
26.60
9.0000
9.3789
9.7656
10.16O
7.0686
7.3662
7.6699
7.9798
9.4248
9.6211
9.8173
10.014
|
36.21
36.68
37.97
39.39
27.65
28.73
29.82
30.94
1O.563
10.973
11.391
11.816
8.2958
8.6179
8.9462
9.28O6
10.21O
10.4O7
10.6O3
1O.799
!
40.83
42.30
43.80
45.33
32.O7
33.23
34.40
35.60
12.25O
12.691
13.141
13.598
9.6211
9.9678
10.321
1O.68O
10.996
11.192
11.388
11.585
H
46.88
48.45
60.05
61.68
36.82
38.O5
39.31
40.59
14.O63
14.535
15.O16
15.5O4
11.O45
11.416
11.793
12.177
11.781
11.977
12.174
12.37O
192
SQUARE AND ROUND BARS.
>r DiuoeUr
Afl Inches.
Weigh: of
D B«
One Koot long.
63.33
65.O1
66.72
68.46
We:?ht of
Das *'no: long.
O*f
in ^. inches.
4re» of .
t O Bar
in sq. inches.
of O Bar
in inches.
4
ji
A
41.89
43.21
44.55
45.91
1G.OOO
16.5O4
17.016
17.535
12.566
12.962
13.364
13.772
12.566
12.763
12.959
13.155
T5
60.21
61.99
63.8O
65.64
47.29
48.69
60.11
61.55
18.O63
18.598
19.141
19.691
14.180
14.607
15.O33
15.466
13.352
13.548
13.744
13.941
1
H
67.60
69.39
71.3O
73.24
63.01
64.60
£6.00
67.52
20.25O
20.816
21.391
21.973
15.904
16.349
16.800
17.267
14.137
14.334
14.53Q
.14.72(3
1
75.21
77.20
79.22
81.26
69.07
60.63
32.22
63.82
22.563
23.160
23.766
24.379
17.721
18.19O
18.665
19.147
14.923
15.119
15.315
15.512
s
83.33
85.43
87.65
89.70
65.45
67.10
68.76
70.45
25.00O
25.629
26.266
26.910
19.635
20.129
2O.629
21.135
157O8
15.9O4
16.1O1
16.297
I
91.88
94.08
96.30
98.55
72.16
73.89
75.64
77.4**
27.563
28.223
28.891
29.666
21.648
22.166
22.691
23.221
16.493
16.69O
16.886
17.082
A
A
100.8
103.1
106.5
IO7.8
79.19'
81.00
82.83
84.69
3O.250
30.941
31,641
32.348
23.758
24.3O1
24.85O
25.400
17.279
17.475
17.671
17.868
y
it
11O.2
112.6
116.1
117.F
86.56
88.45
90.36
92.29
33.063
33.785
34.516
35.254*
25.967
26.635
27.10G
27.688
18.O64
..18.261
18.653
193
SQUARE AND ROUND BARS.
(CONTINUED)
. — , . . —
4
^•kiifJS
We.pht of
I Weight of
ire* of
inn of
Circumferan*
fcimetei
G •-
O B»<
QBar
0 Bar
of O Bw>
Inches.
One Foot long
Oae foot long.
in sq. incbas.
in sq. inches
in inch**.
3
120.0
94.25
36.00O
28.274
18.85O
122.5
96.22
36.754
28.806
19.O46
¥
125.1
98.22
37.516
29.465
19.242
127.6
10O.2
38.285
30.O69
19.439*
130.2
102.3
39.063
30.680
19.635
,
132.8
1O4.3
39.848
31.296
19.831
•i
135.5
106.4
4O.641
31.910
20.028
A
138.1
1O8.5
41.441
i 32.548
20.224
. 4
•I
14O.8
110.6
42.250
33 183
20.420
143.6
112.7
43.O66
33.824
20.617
146.3
1149
43.891
34.472
2O.813
H
149.1
117.1
44.723
35.125
21.000
f *
151.9
119.3 "
45.663
35785
21.206
4.1
154.7
121.5
46.410
36.450
21.402
l|
157.6
123.7
47.266
37.122
21.598
160.4
126.0
48.129
37.800
21,79$
i
.
i
163.3
128.3
49.000
38.485
21,90*
166.3
13O.6
49.879^
39.175
-22.187
u f
169.2.
132.9
50.766
39.871
13s
172.2
135.2 .
51.660
40.674
22.'58O
i*
175.2
137*
52 563
41.282
22.777
1$L
178.2
14O.O
63^473
41.997
22.973
t
181.3
184.4
142.4
144.8
64.391
55.318
'42.718
43.446
23.160
23.366
I
187.5
147.3
56.25O
44.179
23.662
iV
190.6
149.7
67.191
44.918
23.758
f
193.8
152.2
68.141
45.664
23.955
197.0
154.7
59.098
46.415
,24.151
f
500.2
157.2
60.063
47.173
24.347
H
203.5
159.8
61.O35
47.937
24.544
1
2O6.7
162.4
62.O16
48.707
24.74O
il
210.0
164.9
63.0O4
49.483
24.030
194
SQUARE AND ROUND BAfcS.
(CONTINUED.)
feekam
n Inches.
One Foot long
Weight of
QBar
One foot long
Arctof "
in sq. inches.
Area of
O Bar
in sq. inches.
Cireiunferenc*
of O **f
8
213.3
167.6
64.000
50.265
26.133
A
216.7
170.2
65.004
61.O54
25.329
i
220.1
172.8
66.O10
51.849
25.525
A
223.5
175.5
67.035
62.649
25.722
'i
226.9f
J78.2
68.063
53.456
25.918
ft
23O.3
180.9
69.098
54.269
26.114
i
23Q.8
183.6
70.141
65.088
26.311
A
237.3
186.4
71.191
65.914
26.6O7
Fi
1*
240.8
189.2
72.260
56.745
26.704
! (,
244.4
191.9
73.316
67.583
26.9<X>
fY
248.0
194.8
74.391
58.426
27.096
251.6
197.6
75.473
69.276
27.293
1
255.2
200.4
76.563
60.132
27.489
'11
258.9
203.3
77.660
60.994
27.685
ft
262.6
206.2
78.766
61.862
27.882
H
266.3
2O9.1 -
79.879
62.737
28078
v
*•
m*
0)
9
270.0
J2121 '
81.000
63.617
28.274
273.8 1
215.0 r
82.129
64.5O4
28.471
I i I
277.61
218.0
83.266
65.397
28.667
Al
281.41
221.O
84.410
66.296
28.863
IT"
^285.2
224.O
85.563
67.201
29.060
'A
289.1
.227.0.
t 86723
68.112
29.256
293.0
230.1
187JB91
69.029
29.452
A'
296.9
233.2
P9.066
69.953
29.649
|»
300.8
236.3 "•
90.250
70.882
29.845
1
3O4.8
308.8
312.8
239.4
242.5 I
2*5.7
91.441
r 92.641
93.848
71.818
72.76O
73.7O8
3O.O41
30.239
30.434.
I
316.9
248.9
95.063
74.662
30.63r
ft-
321.0
252.1
96.285
75.622
3o]827j
1-
325.1
255.3
97.516
76.589
31.O23
It
329.2
1
258.5
98.754
77.561
§1.220
195
SQUARE AND ROUND BARS.
(CONUINUED.)
iiekaess
Duuaetw
T
Weight of
On* Foot long.
Weight of
QB*r
On* Foot long.
ATM of
in iq. inches.
ireiof
OB-
in sq. inches.
CircuoftraM
of O B«*
in inchM.
0
333.3
261.8
100.00
78.540
31.416
1*5
^37.5
265.1
1O1.25
79.525
31.612
£
341.7
268.4
1O2.52
80.616
31.8O9
A
346.0
271.7
103.79
81.513
32.005
*
350.2
275.1
105.06
82.516
32.201
A
354.5
> 78.4
106.36
83.625
32.398
I
358.8
28i.8
107.64
84.641
32.694
A
363.1
285.2
1O8.94
85.662
32.79O
i
367.5
288.6
' \ 10.26
86.590
32.987
A
371.9
292.1
1O1.57 87.624
33.183
1
376.3
295.5
112.89 88.664
33.379
a
380.7
299.0
114.22 89.710
33.576
i
385.2
302.5
115.56
90.763
33.772
it
389.7
306.1
116.91
, V821
33.968
i
394.2
309.6
118.27
92.386
34.166
H
398.8
313.2
119.63
93.966
34.361
f
L
403.3
318.8
121.00
95.033
i S4.568
X
407.9
320.4
122.38
96.116
34.764
|
412.6
324.0
123.77
97.2O6
34.^50
nr
417.2
327.1/
126.16
98.301
35.147
1
421.9
331.3
126.56
99.402
35.343
A
426.6
335.O
127.97
10O.61
35.539
|
431.3
333.7
129.39
kOl.62
35.736
A
436.1
342.5
130.82
102.74
35.932
i
440.8
346.2
132.25
1O3.87
36.128
A
445.6
35O.O
133.69
105.00
36.325
1
450.6
353.8
135.14
106.14
36.521
H
455.3
367.6
136.60
107.28
36.717
f
460.2
361.4 .
. 138.06
108.43
36.914
H
465.1
365.3-
139.64
109.59
37.11O
|
470.1
369.2
141.02
11O.75
37.3O6
**
475.0
373.1
142.60
111.92
37,503
196
Weight of Sheets of Wrought Iron, Steel Cop*
per and Brass. (From Haswell.)
er Square Foot. Thickness by Birmingham Gauge.
"•O.rf
^ftagai
Thickness
in inches.
Iron.
Steel.
copy.
Brass.
0000
.454
18.22
18.46
20.57
19.43^
t ooo
.425
17.05
17.28
19.25
18.19
>00
.38
15.25
15.45
17.21
16.26
o
.34
13.64
13.82
15.4O
14.55
1
.3
12.04
12.20
13.59
12.84
2
.284
11.40
11.55
12.87
12.16
3
.259
10.39
10.53
11.73
11.09
4
.238
9.55
9.68
10.78
10.19
6
.22
8.83
8.95
9.97
9.42
6
.203
8.15
8.25
9.20
8.69
7
.18
7.22
7.32
8.15
7,70
8
.165
6.62
6.71
7.47
,7,06
,0
.148
5.94
6.02
6.70
6.33
10
.134
6.38
6.45
6.07
6.74
11
.12
4.82
4.88
5.44
6.14
12
.109
4.37
4.43
4.94
4.67
13
.095
3.81
3.86
4.30
^4.07
14
.083
3.33
3.37
3.76
3.55
15
.072
2.89
2.93
3.26
3.08
16
.065
2.61
2.64
2.94
2.78
17
.058
2.33
2.36
2.63
2.48
(18
.049
1.97
1.99
2.22
2.10
19
.042
4.69
171
.90
1.80
20
.035
1.40
1.42
.59
1.60
21
.032
1.28
1.3O
.45
1.37
.22
.028
1.12
1.14
.27
1.20
'23
.025
1.00
1.02
.13
1.07
24
.022
.883
.895
.00
.942
25
.02
.803
.813
.906
.856
26
.018
.722
.732
.815
.770
27
.016
.642
.651
.725
.685
28
.014
.662
.569
.634
.599
29
.013
.522
.529
.589
.556
30
.012
.482
.488
.544
.514
31
.01
.401
'.407
.453
.428
32
.009
.361
.360
.408
.385
33
.008
.321
.325
.362
.342
34
.007
.281
.285
.317
.300
35
.005
.201
.203
.227
.214
Specific Gravity,
7.704
7.806
8.698
8.218
Weight Cubic Foot,
481.25
487.75
543.6
613.6 A
" Inch,
.2787
.2823
314$
.297?
i97
Weight of Sheets of 'Wrought Iron, Steel, Cop-
per and Brass. From Haswell.
Weight per Square Foot. Thickness by American (Brown oc
Sharpen) Gauge.
la of
fa*g*
thickness
in inches.
Iron.
Steel.
Copper.
Brass.
oooo
.46
18.46
18.7O
20.84
19.69
000
.4096
16.44
16.66
18.56
17.53
00
.3648
14.64
14.83
16.53
15.61
0
.3249
13.04
13.21
14,72
13.90
1
.2893
11.61
11.76
13.11
12.38
2
.2576
10.34
10.48
11.67
11.03
3
.2294
9.21
9.33
10.39
9.82
4
.2043
8.20
8.31
9.26
8.74
5
.1819
7.30
7.40
8.24
7.79
6
.1620
6.50
6.59
7.34
6.93
7
.1443
5.79
5.87
6.54
6.18
8
.1285
5.16
5.22
5.82
5.50
9
.1144
4.59
4.65
5.18
4.9O
1O
..1019
4.09
4.14
4.62
4.36
11
.0907
3.64
3.69
4.11
3.88
12
.0808
3.24
3.29
3.66
3.46
13
.0720
2.89
2.93
3.26
3.08
14
.0641
2.57
2.61
2.90
2.74
15
.0571
2.29
2.32
2.69
2.44
16
,0508
2.04
2.07
2.30
2.18
17
.O453
1.82
1.84
2.05
1.94
18
.0403
1.62
1.64
1.83
1.73
19
.0359
1.44
1.46
1.63
1.54
20
.032O
1.28
1.30
1.45
1.37
21
.0285
1.14
1.16
1.29
1.22
22
.O253
1.02
1.03
1.15
1.08
23
.0226
.906
.918
1.02
.966
24
.0201
.807
.817
.911
.860
25
.0179
.718
.728
.811
.766
26
.0159
.640
.648
.722
.682
27
.0142
.570
.577
.643
.608
28
.0126
.507
.514
.573
.541
29
.0113
.452
.458
.510
.482
3O
.O10O
.402
.408
.454
.429
31
.0089
.358
.363
.404
.382
32
.0080
.319
.323
.360
.340|
33
.0071
.284
.288 .321
.303
34
.O063
.253
.256 .286
.270
35
.0056
.225
.221 j .254
.240;
I98
WEIGHTS OF FLAT ROLLED IRON PER
LINEAL FOOT.
For Thicknesses from 1-16 in. to 2 in., and
Width from i in. to 12^ in.
Iron weighing 480 Ibs. per cubic foot.
fUeknesf
la laches.
1"
w
IK"
w
2"
w
2K"
2V<
12"
A
208
260
.313
.365
.417
.409
-521
.573
2.50
i
.417
.521
.625
.729
.833
.938
1.C4
1.15
5.CO
A
.625
.781
.938
1.09
1.25
1.41
1.56
1.72
7.CO
.833
1.04
1.25
1.46
1.67
1.88
2.08
2.29
10.00
A
1.04
1.30
1.56
1.C2
2.08
2.34
2.GO
2.8G
12.60
i
1.26
1,56
1.88
2.19
2.LO
2.81
8.13
3.44
15.CO
A
1.46
1.82
2.19
2.55
2.92
3.28
8.C5
4.01
17.50
*
1.67
2.08
2.50
2.92
3.33
3.75
4.17
4.58
20.00
&
1.88
2.34
2.81
3.28
8.75
4.22
4.C9
5.16
22.50
ft
2.08
2.60
8.13
3.C5
4.17
4.C9
6.21
5.73
25.CO
2.29
2.86
3.44
4.01
4.58
5.16
6.73
6.SO
27.50
jl
2.50
3.13
3.75
433
5.00
5.G3
625
6.88
30.CO
II
2.71
339
4.06
474
5.42
6.09
6.77
7.45
"kco
i
2.92
3.G5
4.38
5.10
6.83
6.56
719
802
33.CO
3.13
3.91
4.69
5.47
6.25
703
7.81
8.59
87.50
i
3.33
4.17
6.00
5.83
6.67
7.60
8.33
9.17
40.00
i&
8.54
4.43
5.31
6.20
7.08
7.97
8.85
9.74
42.50
u
3.75
4.69
5.63
6.56
7.50
8.44
9.38
10.31
45.00
3.%
4.95
5.94
6.93
7.92
8.91
9.90
10.89
47.50
u
4.17
5.21
6.25
7.29
8.33
9.38
10.42
11.46
50.00
I*
4.37
5.47
6.56
7.G6
8.75
9.84
10.94
12.03
52.60
if
4.58
6.73
6.88
8.02
9.17
10.31
11.46
12.60
55.00
til
4.79
5.99
7.19
8.39
9.58
10.78
11.98
13.18
57.50
U
5.00
625
7.50
8.75
10.00
11.25
12.50
13.75
60.00
IT'S
5.21
6.51
7.81
9.11
10.42
11.72
1302
1432
62.50
If
5.42
6.77
8.13
9.48
10.83
12.19
13.54
14.90
65.00
Ifl
5.63
7.03
8.44
9.84
1125
12.66
14.06
15.47
67.50
5.83
7.29
8.75
10.21
11.67
13.13
14.58
16.04
70.00
Hi
6.04
7.55
9.06
10.57
12.08
13.59
15.10
16.61
72.50
If
625
7.81
9.38
10.94
12.50
14.06
15.63
17.19
75.00
tf*
6.46
8.07
9.69
11,30
12.92
14.53
16.15
1776
77.50
8
6.67
8.33
10.00
11.67
13.33 '15.00
16.67
18.33
80.00
199
WEIGHT OF FLAT ROLLED IRON PE*
LINEAL FOOT.
(CONTINUED.)
Thickness
IB Inebn.
3"
1
3'i"
3X»
4" 4^"
4tJ
4%"'
is-
rs
.625
.677: 729
.781
833
.885
.938
.990
2.50
5
1.25
1.35
1 46
1.56
167
1.77
1.88
1.98
5.00
A
1.88
2.03 2.19
234
250
2.66
2.81
2.97
7.50
V
2.50
2.71
2.92
8.13
333
3.54
3.75
396
10.00
^
313
339
3.65
3.91
417
4.43
4.69
4.95
12.50
t
375
406
48g
469
600
5.31
563
5.94
15.00
* ?
4.38
474
6.10
6.47
6.83
0.20
6.56
6.93
17.50
i
5.00
5.42
6.83
6.25
6.67
7.08
7.50
7-92
20.00
A
6.63
6.09
6.56
7.03
750
797
844
8.91
22.50
•I
6.25
6.77
7.29
7.81
8.33
8.85
938
9.90
25.00
6.88
7.45
8.02
8.59
9.17
9.74
10.31
0.89
27.50
1
7.50
8.13
8.75
9.38
10.00
10.63
1155
1.88
30.00
41
8.13
8.80
948
10.16
10.83
11.51
12.19
2.86
32.50
|
8.75
948
10.21 i 10.94
11.67
12.40
13.13
3.85
35.00
i!
9.38
10.16
10.94
11.72
12.50
13.28
14.06
4.84
37.50
10.00
10.83
11.67
12.50
13.33
14.17
15.00
15.83
40.00
f&
1063
11.51 12.40
13.28
14.17-
L5.05
15.94
6.8g
42.50'
**
11.25
12.19
13.13
14.06 15.00
15.94
10.88
17.81
45.00
11.88
12.86
13.85
14.84 15.83
1&82
17.81
18.80
47.50
^
12.50
13.54
14.58
15.63
16.C7
17.71
18.75
19.79
50.00
13.13
14.22
15.31
15,41
17.50
18.59
19.C9
20.78
52 oO
j'a
13.75
1490
16.04
17.19
18.33
19.48
20.63
21.77
65'.00
1T75
14.38
15.57
16.77
17.97
19.17
20.36
21.56
22.76
57.50
15.00
16.25
17.50
18.76
20.00
21.25
22.50
23.75
60,00
1TV
15.63
16.93
18.23
19.53
20.83
22.14
23.44
24.74
C2.50'
16.25
17.60
18.96
20.31
21.67
23.02
24.33
25.73
65.00
pi
16.88
18.28
19.69
21.09
22.50
23.91
25.31
26.72
07.60
«i
17.50
18.95
20.42
21.88
23.S3
24.79
26.25
27.71
70.00
«
18.13
18.75
19.38
19.C4
20.31
20.99
21.15
21.88
22.60
22.66
23.44
24.22
£4.17
25.00
25:83
25.C8
26.56
27.45
27.19
28.13
29.06
23.70
29.ca
30.C3
72.00
75.00
77.59
2
20.00
21.67
23.33
25.00 J26.67
28.33
30.00
01.07
CO.OO
WEIGHTS OF FLAT ROLLED IRON PER
LINEAL FOOT.
(CONTINUED.)
thickness
fc Inches,
5"
a*-
w
~~
G"
«H«X"
w
12"
A
1.04
1.09
1.15
1.20
1.25
1.30
1.35
1.41
2.50
2.08
2.19
2.29
2.40
2.50
2.60
2.71
2.81
5.00
I*?
3.13
3.28
3.44
3.59
3.75
8.9i
4.06
4.22
7.50
\
4.17
4.38
4.58
4.79
5.00
5.21
5.42
5.63
10.00
^
5.21
5.47
573
599
6.25
6.51
6.77
7.03
12.50
Y
6.25
6.56
6.88
7.19
7.50
7.81
8.13
8.44
15.00
7.29
7.66
8.02
8.39
8.75
9.11
9.48
9.84
17.50
y
8.33
8.75
9.17
9.58
10.00
10.42
10.83
11.25
20.00
A
9.38
9.84
10.31
1078
11.25
11.72
12.19
12.66
22.50
10.42
10.94
11.46
1198
12.50
13.02
13.54
14.06
25.00
H
11.46
12.03
12.60
1318
13.75
14.32
14.90
15.47
27.50
4
12.50
13.13
13.75
14.38
15.00
15.63
16.25
16.88
30.00
H
13.54
14.22
1490
15.57
16.25
16.93
17.60
18.28
32.50
14.58
1531
16.04
16.77
17.50
18.23
18.96
19.69
35.00
H
15.63
16.41
17.19
17.97
18.75
19.53
20.31
21.09
37.50
16.67
17.50
1833
1917
20.00
20.83
21.67
22.50
4000
1
i A
17.71
18.59
19.48
20.36
21.25
22.14
23.02
23.91
42.50
18.75
19.69
20.63
21.56
22.50
23.44
24.38
25.31
45.00
i^
19.79
20.78
2177
22.76
23.75
24.74
25.73
26.72
47.50
1 i
20.83
21.88
22.92
23.96
25.00
26.04
27.08
28.13
50.00
l£
21.88
22.97
24.06
25.16
26.25
27.34
28.44
29.53
52.50
^ !
22.92
24.06
25.21
26.35
27.50
28.65
29.79
30.94
55.00
!A
23.96
25.16
26.35
27.55
28.75
29.95
31.15
82.34
57.50
25.00
26.25
27.50
28.75
30.00
31.25
32.50
83.75
60.00
IT'*
26.04
27.34
28.65
29.95
31.25
32.55
33.85
35.16
62.50
M
27.08
28.44
29.79
31.15
32.50
83.85
35J21
36.56
65.00
28.13
29.53
30.94
32.34
83.75
35.16
86.56
37.97
67.50
if
29.17
30.63
32.08
83.54
35.00
36.46
37.92
39.38
70..00
HI
30.21
31.72
33.23
34.74
36.25
3776
39.27
40.78
72.50
31.25
32.81
34.38
35.94
37.50
39.06
40.63
42.19
76.00
*tt
32.29
83.91
35.52
37.14
3875
40.36
41.98
43.59
77.50
e
33.33
35.00 36.67 j 38.83 j 40.00
41.67
43.33
45.00
80.00
WEIGHTS OF FLAT ROLLED IRON PER
LINEAL FOOT.
(CONTINUED.)
Thickness
ID laches.
1"
7K"
7*»
7%<<
,
U>4
b>2
u;4
As
1.46
1.51
1.56
1.61
167
1.72
1.77
1.82
250
1
2.92
302
313
3.23
3.33
3.44
3.54
365
60C
A
4.38.
4.53
4.69
4.84
6.00
516
631
6.47
7.oO
Y
5.83
6.04
6.25
6.46
6.67
688
708
7.29
10.00
IV
7.29
7.55
7.81
8.07
8.33
8.59
8.85
9.11
12.50
8.75
906
9.38
9.69
10.00
10.31
1063
10.94
1500
ll
10.21
10.67
10.94
11.30
11.67
12.03
12.40
1276
1750
1167
12.08
12.50
12.92
13.33
1375
1417
1458
2000
I\
1313
1359
14.06
14.53
1500
1547
1594
16.41
2250
1
14.58
1510 15.63
16.15
1667
1719
1771
18.23
2500
4
16.04
16.61
1719
1776
18.33
1891
1948
20.05
27.50
17.60
1813
1875
1938
2000
20.63
21.25
21.88
30.00
H
1896
1964 2031
2099
2167
22.34
23.02
23.70
3250
1
2042
21 15 21 88 22.60
23.33
24.06
24.79
2552
35.00
H
2188
2333
22.66
2417
23.44
25.00
24.22
25.83
25.00
26.67
25.78
27.50
26.56 27.34
28.3312917
37.50
4000
,r
2479
2568
26.56
27.45
28.33
29.22
30.10
3099
4250
I |
26.25
2719
28.13
29.06
30.00
30.94
3188
32.81
45.00
J 8
27.71
28.70
29.69
30.68
81.67
32.66
33.65
3464
47.50
1 1
29.17
30.21
31.25
32.29
33.38
34.38
3542
36.4C
6000
irV"
30.62
3172
32.81
33.91
35.00
36.09
3719
38.28
68.50
If*
32.08
33.23
34,38
35.52
36.67
37.81
38.96
4010
55.00
4
33.54
34.74
35.94
37.14
38.33
39.53
4073
4193
57.50
35.00
36.25
37.50
38.75
40.00
41.25
42.50
43.75
60.00
IT'S
36.46
3776
39.06
40.36
41.67
42.97
44.27
45.57
6250
l|
3792
39.27
40.63
41.98
43.33
44.69
46.04
47.40
6500
Ifl
39.38
40.78
42.19
43.59
45.00
4641
47.81
49.22
67.50
'40.33
42.29
43.75
45.21
46.67
48.13
49.58
51.04
70.00
HI
42.29
43.80
45.31
46.82
48.33
49.84
51.35
52.86
>^50
H
43.75
45.31
46.88
48.44
50.00
51 56
53.13
54.69
75^00
HI -
45.21
46.82
48.44
50.05
51.67
53.28 [ 54.90
56.51
77.50
&
46.67
48.33
50.00 1 51.67 j 53.33
55.00 56.67 1 58.33
80.00
WEIGHTS OF FLAT ROLLED IRON PER
LINEAL FOOT.
(CONTINUED.)
inlMfra.
9"
9tf<
9V
9*"
10"
UH»
UH"
10|"
12"
A
1.88
1.93
1.98
2.03
2.08
2.14
2.19
254
2.50
i
S.75
3.85
8.96
4.06
4.17
4.27
4.38
4.48
6.00
«*
6.63
6.78
6.94
6.09
6.25
6.41
6.56
6.72
7.50
1
7.60
7.71
7.92
8.13
8.33
8.54
8.75
8.96
10.00
A
0.38
9.64
9.90
10.16
10.42
10.68
10.94
1150
12.50
r*t
1156
11.56
11.88
12.19
12.60
12.81
13.13
13.44
15.00
A
13.13
13.49
13.86
1452
14.68
14.95
15.31
15.68^
-17.50
16.00
15.42
15.83
1655
16.67
17.08
17.50
17.92
20.00
•A
16.88
17.34
17.81
1858
18.75
1952
19.69
20.16
22.50
18.75
19.27
19.79
20.31
20.83
21.35
21.88
22.40
26.00
'i*
20.63
2150
21.77
22.34
22.92
23.49
24.06
24.64
27.60
i
22.60
23.13
23.75
24.38
25.00
25.62
2655
26.88
30.08 1
if
24.38
25.05
25.73
26.41
27.08
27.76
28.44
29.fl
32.50
i
2655'
26.98
27.71
28.44
29.17
29.90
30.63
31.36
35.00
ft
28.1ft
28.91
29.69
80.47
31.25
32.03
32.81
33.59
37.50
\v
30.00
30.83
31.67
32.60
33.33
34.17
35.00
35.83
40.00
31.88
82.76
33.65
34.53
35.42
36.30
37.19
38.07
42.50
11
33.75
35.63
34.69
36.61
35.63
37.60
36.56
38.59
87.50
89.68
88.44
40.57
39.38
41.56
40.31
42.55
45.00
47.50
87.50
88.54
39.58
40.63
41.67
42.71
43.75
44.79
60.00
1 •
39.38
40.47
41.56
42.66
43.75
44.84
45.94
47.03
62.50
11
41.25
42.40
43.54
44.69
45.83
46.98
48.13
4957
65.00
fi
43.13
44.32
45.52
46.72
47.92
49.11
60.31
51.51
57,50
M
45.00
4655
47.60
48.75
60.00
6155
52.60
53.75
60.00
a A
46.88
48.18
49.48
50.78
62.08
53.39
54.69
55.99
62.50
if
48.75
60.10
51.46
62.81
54.17
55.52
66.88
5853
65.00
50.63
52.03
53.44
64.84
5655
57.66
59.06
60.47
€7.50
i}**
52.50
53.96
65.42
56.88
58.33
59.79
6155
62.71
70.00
4H
54.38
65.89
57.40
58.91
60.42
61.93
63.44
64.95
72.50
1 1
6655
67.81
59.38
60.94
62.50
64.06
65.63
67.19
75.CO
Ul
58.13
59.74
C1.35
62.97
64.58
6650
67.81
69.43
77.50
2
60.00
61.67
63.33
65.00
66.67.
68.33.
70.00
71.G7
80.00
WEIGHTS OF FLAT ROLLED IRON PER
LINEAL FOOT.
(CONTINUED.)
Tinckiees
n f jc'hcs.
m
1H"
11 r
III"
12"
2i"
12*"
122"
T:
2.29
2.34
2.40
2.45
2.50
2.55
2.60
2.66
|
4.58
4.69
4.79
490
5.00
5.10
5.21
5.31
J9
6.88
7.03
7.19
7.34
7.50
7.66
7.81
7.97
i
9.17
9.38
9.58
9.79.
10.00
10.21
10.42
10.63
j
11.46
11.72
11.98
12.24
12.50
12.76
13.02
13.28
i
3
13.75
14.03
14.38
14.69
15.00
15.31
15.63
15.94
A
10.04
16.41
16.77
17.14
17.50
17.86
18.23
18.59
1 0
18.33
18.75
19.17
19.58
20.00
20.42
20.83
2155
T95
2063
21.09
21.56
22.03
22.50
22.97
23.44
23.91
|
22.92
23.44
23.96
24.48
25.00
25.52
26.04
26.56
U
25.21
25.78
26.35
26.93
27.50
28.07
28.65
2952
V ,
27.50
28.13
28.75
29.38
30.00
30.63
31.25
31.88
9
41
2979
30.47
31.15
31.82
32.50
33.18
33.85
34.53
f
32.08
32.81
33.54
34.27
35.00
35.73
36.46
37.19
H
34.38
35.16
35.94
36.72
37.50
38.28
39.06
39.84
38.67
37.50
38.33
39.17
40.00
40.83
4167
42.50
1-rV
38.96
39.84
40.73
41.61
42.50
43.39
4457
45.16
(I?
41.25
42.19
43.13
44.06
45.00
45.94
46.88
47.81
4
43.54
44.53
45.52
46.51
47.50
48.49
49.48
50.47
1?
45.83
46.88
47.92
48.96
50.00
51.04
52.08
63.13
t&
48.13
4952
50.31
51.41
52.50
53.59
54.69
65.78
if
50.42
51.58
52.71
53.85
55.00
56.15
5759
68.44
i.A
52.71
53.91
55.10
56.30
57.50
58.70
59.90
61.09
IT
55.00
56.25
5750
58.75
60.00
61.25
62.50
63.75
IT'*
5759
68.59
59.90
6150
62.60
63:80
65.10
&S.41
H
59.58
60.94
6259
63.65
65.00
66.35
67.71
69.08
JH
61.88
63.28
64.69
66.09
67.50
68.9
70.31
71.72
i?
64.17
65.63
67.08
68.54
70.00
71.46
72.92
74.38
Ht
66.46
67.97
69.48
70.99
72.50
74.0
75.52
77.03
if
68.75
70.31
7188
73.44
75.00
76.56
78.13
79.6?
w
71.04
72.66
7487
75.89
7/.50
79.1
80.73
82.34
e -
73.33
75.00
76.67
78.33
80.00
81.67
83.33
85.00
1
204
Weight of Rivets, and Round Headed Bolts
Without Nuts, Per 100.
Length from under head. One cubic foot weighing 480 Ibs.
rngii.
iches.
•K"
Dia.
K
%"
Dia.
DUL
%"
Dia.
1"
Dia.
Dia.
Dia.
Vi
5.4
12.6
21.5
28.7
43.1
65.3
91.5
123.
\%
6.2
13.9
23.7
318
47.3
70.7
98.4
133.
1%
6.9
153
25.8
34.9
51.4
76.2
105.
142.
2
7.7
16.6
27.9
87.9
55.6
81.6
112.
150.
%
8.5
18.0
30.0
41.0
59.8
87.1
119.
159.
2M
9.2
19.4
32.2
441
63.0
925
126.
167.
2%
10.0
20.7
34.3
47.1
68.1
98.0
133.
176.
U
10.8
22.1
36.4
50.2
72.3
103.
140.
184
'*
3^
11.5
23.5
88.6
533
765
109
147.
193.
8)£
12.3
24.8
407
564
807
114.
154.
201.
3%
13.1
26.2
428
594
84.8 i 120.
161.
210.
4
13.8
27.5
45.0
62.5
800
125.
167.
218.
14.6
28.9
47.1
65.6
932
131.
174
227.
4}£
15.4
30.3
49.2
68.6
974
136.
181.
236.
43/
16.2
81.6
51.4
717
102
142.
188.
244.
6 ^
16.9
33.0
53.5
74.8
106.
147.
195.
253.
%
17.7
34.4
556
77.8
110.
153.
202.
261.
5^
18.4
85.7
57.7
80.9
114.
158.
209.
270
65.4
19.2
37.1
59.9
' 84 0
118
163.
216.
278.
6
20.0
38.5
62.0
87.0
122.
169
223.
287.
6M
21.5
41.2
66.3
93.2
131
180*
236.
304 '
7
230
43.9
70.5
993
139.
191.
250
821.
7K
24.6
46.6
74.8
106.
147.
202. *
264.
888.
8
26.1
49.4
79.0
112.
156.
213.
278.
855.
/
4
8^£
27.6
52.1
83.3
118.
164.
223
292 i 37f,
9
292
54.8
876
124.
173
234.
30C
389.
9K
80.7
67.6
91.8
130.
18!
245.
319.
406.
10
32.2
60.3
96.1
136.
189.
256.
333.
423.
10>£
83.8
63.0
101.
142.
198
267.
347.
440/
11
35.3
65.7
105.
148.
206.
278.
361.
457.
UK
86.3
685
149.
155.
214.
289
375.
474.
1?c*
38.4
71.2
113.
161.
223.^
300.
388.
491.
<*
leads.
1.8
5.7
10.9
13.4
22.2
88.0
57.0
205
WEIGHT OP CAST IRON PER LINEAL FOOT. —Example: What Is
weight of a cast iron plate 2" x 14" x one foot long? Ans. — The
thickness multiplied by width equals 28" of sectional area.
In the sixth column, we find that 87^ Ibs. is the weight of a piece
with a sectional area of 28" and one foot long.
Area!
Area T Hfl
Inches.; Lb8'
Area
Inches
Lbs.
Area' T h_
Inches. Lb9'
Area
Inches
Lbs.
1
i
1
If
.20
6
18.75
21 V
67.19
48
194.38
69
215.63
fc
.39
6'4
19.53
22
68.75
43$ 135.94
70
218.75
•j\
.69
6$
20.31
22V
70.31
44 137.5
71
221.88
v»
.78
6*
21.09
23
71.88
4 4 $[1*9.04
72
225.0
I5?
.98
7
1 21.88
28V
73.44
45
140.63
73
228.13
2£
1.17
71'4
' 22.66
24
75.00
45$
142.19
74
231.25
A
1.37
iy
23.44
24?xJ
76.56
46
148.76
75
234.38
y*
t.56
7%.
24.22
26
78.13
46$ 145.31
76
237.6
A
1.76
8
25.00
25 y2
79.69
47 1146.87
77
240.63
/M
1.95
8'4
26.78
26
81.25
47J4,;1 48.44
78
243.75
H
2.15
26.56
26^
82.81
48 150.00
79
249.87
3£
2.34
83K
27.34
27
84.38
48$ 151.56
80
250.00
H
2.54
9
28.13
27$
85.94
49
163.12
81
253.12
?'H
2.78
9V*
28.91
28
87.5
49$
154.69
82
256.25
it
2.93
9!^
29.69
28V£
89.06
50
156.25
83
259.38
i
3.125
ft if
80.47
29
90.63
60$
167.81
84
262.5
IVa
3.51
10
31.25
29$
92.19
51
159.38
85
265.63
IVi
3.91
lOVi
82.03
30
93.75
61V£
160.94
86
268.75
1%
4.30
ioV£
32.81
30$
95.31
52
162.5
87
271.88
j 1$
4.69
10?4
33.59
31
96.87
52$
164.06
^88
275.00
5
5.08
11
34.38
31$
98.44
53
165.63
89
278.13
1%
6.47
ni/i
35.16
32
100.00
63^
167.19
90
281.25
>'•<
5.86
1 " /2
35.94
32^
101.56
54
168.75
91
284.38
6.25
11%
36.72
33
103.12
W6
170.31
92
287.6 J
2Vs
6.64
12
37.6
33$
104.69
65
171.88
93
290.66
2 1^
7.03
ISVJj
39.06
34
106.25
W4
173.44
94
293.76
2%
7.42
13
40.63
84$
107.81
56
175.00
95
296.87
2%
7.81
13$
42.19
85
109.38
66$
176.56
96
300.00
2%
8.20
14
43.75
35$
110.94
57
178.13
97
303.13
8.59
14$
45.31
36
112.5
57^
179.69
98
306.25
2%
8.98
15
46.87
36$
114.06
58
181.26
99
309.38
8
9.88
15Va
48.44
37
115.63
68$
182.81
100
312.5
3l/£
10.16
16
50.00
87$
117.19
59
184.38
101
315.63
4
10.94
11.72
12 5
17
17V;
51.56
53.12
54.69
38
88 J4
39
118.75
120.31
121.88
59$
60
61
185.94
187.5
190.63
102
103
104
105
318.75
822.88
325.00
328.13
4'/4
13.28
18 56.25
39V£
123.44
62
193.75
106
331.25
4$
14.06
18H 57.81
40
25.00
63
196.87
107
334.88
4*
14.84
19 69.88
4 OX>
26.56
64
200.00
108
837.5
6 4ft
lo.G3
19$] 60.94
41
1-28.13
65
•203.125
109
340.63
&^
16.41
•JO 62.5
41$ 129.69
C« -206.25
110
343.75
&$
17. 19
20? .j 64.06
4'J ! 131. 2 5
« 1-209.38
111
346.87
112
350. OQ
206
ftlNEAR EXPANSION OP SUBSTANCES
BY HEAT.
To find the increase in the length of a bar of any material due
to an increase of temperature, multiply the number of degrees
of increase of temperature by the coefficient for 100 degrees and
by the length of the bar, and divide by 100.
NAME OF SUBSTANCE.
Coefficient for 100 c
Fakrenheit.
Coefficient for 180°
Fahrenheit, or IOC1
CenUgradt
Baywood, (in the direction of the J
.00026
TO
.00046
TO
grain, dry,) » •
I
.O0031
00057
Brass, (cast,) -
.
.O01O4
00188
" (wire,)
•f
.00107
.00193
Brick, (fire,) .
*,
.0003
.0005
Cement, (Roman,) - ^
/ ^
.0008
.0014
Copper, - * *
•'.
.0009
.0017
Deal, (in the direction of the grain, J
'.00024
.00044
dry,) -
Glass, (English flint,) - v *
s.
.00045
.00081
" (French white lead,)
T' ^
.00048
.00087
Gold, . - . v -U >
-."* ^ •
.0008
.0015
Granite, (average,) • - * >
.00047
.OOO85
Iron, (cast,) - • %^ • J
^
.0006
.0011
" (soft forged,) * » •••
.0007
.0012
" (wire,) - :"VA^
"* * '
.0008
.0014
T A ""*
0016
OO9ft
Marble, (Carrara,) - x *• ^
V
.00036
TO
.0006
.00065
to
.0011
Mercury, -x • ,'*?.*
^^
.0033
.0060
Platinum, - *v • ' •
'.
.0005
.0009
f
.0005
.0009
Sandstone, • « - «
TO
TO
1
.0007
.0012
Silver, • , <• ,^
Jf
.0011
.002
Slate, (Wales,) .'fC; .
.0006
.001
Water, (varies considerably
the temperature,)
with ]
.0086 ',
.O155
207
Weight of Bolts per 100, Including Nuts.
1
5
I
2
DIAMETER.
i
A '
«
r7*
1
*'»
1
I
•1
4.
4.36
4.75
7.
7.60
8.
10.60
11.25
12.
1520
16.30
17.40
22.50
23.82
26.16
39.60
41.62
48.75
69.
. ......
*i
6.15
8.50
12.75
18.60
26.47
45.88
72.
.....'.-.
*4
6.60
9.
13.60
19.60
27.80
48.'
75.
116.60
1
2J
6.75
9.60
14.25
20.70
29.12
60.12
78.
121.75
i*
«.*5
10.
16.
31.80
8Q.45
52,25
81.
126.
*i
*7.
11.
16.50
24.
33.10
56.50
87.
134.85
7.76
12.
•9,f
26.20
36.76
60 75
93.10
142.60
207
4*
8.60
13.
19.60
28.40
38.40
66.
99.0^
151.
219
6
9.26
14.
21.
80.60
41.06
69.26
105.20
169.66
22t
6i
10.
16.
22.60
32.80
43.70
73.50
111.26
168.^
240
](• .5
16.
24.
35.
46.35
77.75
117.30
176.60
251
J;
25.60
27.
28.60
87.20
39.40
41.60
49.
51.65
54.30
82.
86.25
90.60
128.35
129.40
135.
185.
198.65
202.
261
27S
284
8
80.
48.80
59.60
94.75
141.50
210.70
295
10
11
46.
48.20
60.40
64.90
70.20
75.50
103.25
111.75
1 20.26
153.60
166 70
177.80
227.75
244.80
261.&6
317
839
360
../v.
12
.. '
.. *N .
52.60
80 8Q
128.75
189.90
278.90
382
13
.'».
8&10
137 25
202
29595
404
14
. : ...
91.40
115.75
214.10
3 1 3.'
426
15
16
17
18
19
' i «
Y"
.... .......
_:
96 70
102.
154 25
162. 70
226.20
238.30
•250.40
262.60
274.70
33005
347.10
364.15
381 20
398.25
44»
470
492
614
636
........
i; 1
107.30
1 12.60
117. HO
179.50
188.
• r._
•• '• 1
80
> ' 1 . . •
• ••• j
188.20
200 50
286.80
415.30
55J
208
TENSILE STRENGTH OF COMMON WOODS.
The strongest wood which grows within the confines of the
United States is that known as "nutmeg" hickory, which,
grows in the valley of the lower Arkansas river. The most
elastic is tamarack. The wood with the least elasticity and
lowest specific gravity is the Picus aurea. The wood having
the highest specific gravity is the blue wood of Texas and
Mexico.
The heaviest of foreign woods are the pomegranate and
the lignum vitas; the lightest is cork, which, however, is a
bark, not solid wood. The tensile strength of the best known
woods is set forth in the following schedule:
WOOD. POUNDS.
Ash 14,000
B3ech 11,500
Cedar 11.400
Chestnut 10.500
Cypress 6,000
Elm 13.400
Fir 12.000
Maple 10.500
White Oak 11.500
Pear 9,800
Pitch Pine 12,000
WOOD. POUNDS.
Larch 9,500
Poplar , .. 7,000
Spruce 10,290
Teak 14,000
Walnut 7,800
Lance 23.000
Locust 20,500
Mahogany 21.000
Willow 13,000
Lignum Vitse 11,800
Pour hundred and thirteen different species of trees grow
in the various states and territories, and of this number 10,
when perfectly seasonable, will sink in water.
TEMPEEING STEEL PUNCHES.
Heat your steel to cherry-red, dress out the punch, cut
off the point the size of a horseshoe nail, then heat to a
cherry-red, immerse it a half inch perpendicularly in the
water, then take it out and stand it up perpendicular, clean
the end with a piece of grinding stone. When you see the
first blue pass over the point, dip it in the water the same
depth as before. Clean it again with the stone, and on the
appearance of the blue again, cool it off. The second blue
is to make the punch tough. The reason for keeping the
punch perpendicular is to allow the atmosphere and the
water to cool all sides equally, and to have it cool straight
and true.
HOW TO MAKE TRACING PAPER.
Take some good thin printing paper, and brush it over on
one side with a solution consisting of one part, by measure,
of castor oil in two parts of meth. spjrit ; blot off and hang up
to dry. You can trace by pencil or ink on this. I have tried
it and done it.
209
IN THE SHOP — TURNING A BALL.
To make a ball as nearly perfect as a billiard ball is made,
is not a piece of work that often falls to the lot of the
machinist or pattern-maker ; but occasionally arises the
necessity for such work.
In pumping where chips, sawdust, or dust is very liable to
lodge on the seat under the valve, ball valves are sometimes
used, because their rolling motion has a tendency to remove
the obstruction, and let the valve seat fairly again. Some of
the old-style locomotive pumps had ball valves ; and, in
tannery work, when small pieces of bark are liable to be ir
the liquid, ball valves can be used to advantage.
I have some such valves, four or five inches in diameter,
for tanner's use. They were of brass, cast hollow, with the
core holes in the shell plugged.
I have seen some costly machines which were made for the
purpose of turning balls; but I have never seen any better
work done by them than can be done in a common lathe.
To make the pattern of a ball, first turn the piece on
centers, using the calipers to get it approximately near the
shape, and then cut off the centers. Next make a chuck-
block of hardwood, A, as shown in the cut, Fig. I. Make
a cup. in the block to receive a small section of the ball, as
also indicated. A blunt, wood center is sometimes used
instead of the steel center with a concave piece of copper, as
represented in cut. Either way will do for making the
pattern. Put the work in the chuck so as to take the first cut
around it in the direction of its former centers, or axis.
Cut lightly, and do not try
to make a wide space — let it
be only a narrow ribbon or
turning — but get it round
in the direction of present
revolution ; then change the
chuck so as to make another
ribbon at right angles to the
first, the first tool marks
being the guide for the depth
of the second cutting. Next
change the work so as to get
a ribbon between the other cuts, and continuing this process of
changing and turning over the whole surface, thus making the
axis of the pattern oY equal length in all directions, and then
the pattern will be round — it will be a ball. At first it might
seern as if some laying off were needed to get {he " ribbons,"
as I have called them, at right angles to each other, but there
is no need of that ; by the eye is enough.
When the machinist comes to finish up the casting, he
can bolt the chuck-block to his face plate, and use his steel
center and a concave piece of copper as represented in the
cut. He will have to use a hand tool, or a scraper, after
getting under the scale.
If the ball becomes too small for the cup in the block, it
is an easy matter to make a new fit by cutting deeper into the
chuck -block.
THE ACTION OF SEA-WATKR ON CAST-IRON
PILES.
Indiana Engineering notes the results of some observa-
tions made by the chief engineer of the B. B. and C. I.
Railway on the cast-iron piles forming the piers of the South
Bassien bridge. The piles were put down in 1862. Two
were found almost as fresh in appearance as when sunk, and
showed no corrosions in specimens cut from the metal. The
deepest corrosion found on any pile was ^ inch ; and this
corrosion was the greatest near low-water mark. The pile
bolts were all in excellent condition. All of these piles have
been exposed to the action of sea-water for about twenty-
five years, and the examination was made to set aside a current
suspicion that they were deteriorating under the action of the
water.
JAPANESE WATER PIPES.
The water supply of Tokio, Japan, is by the wooden water
pipe system, which has been in existence over two hundred
years, furnishing at present a daily supply of from twenty-five
to thirty million gallons. There are several types of water
pipes in use, the principal class being built up with plank,
square, and secured together by frames surrounding them at
close intervals. The pipes, less than six inch, consist of bored
logs, and somewhat larger ones are made by placing a cap on
the top of a log in which a very large groove has been cut.
All the connections are made by chamfered joints, and cracks
are calked with an inner fibrous bark. Square boxes are
used in various places to regulate the uniformity of the flow
of the water, which is rather rapid, for the purpose of pre-
venting aquatic growth. TI.c water is not delivered to the
houses, but into reservoirs oa the sides of the streets, nearly
1 5, ooo in number.
THE HEATING POWER OF FUEL.
The heating power of fuel is ascertained by the foil, »Ting
process, which consists in burning one gramme of the o 1 or
fuel in a small platinum crucible, supported on the bow f>f a
tobacco pipe, and covered by an inverted glass test 4i ,be,
through which is passed a stream of oxygen, while the i pie
is placed under water in a glass vessel. The oxygen i fed
into the test tube by a movable copper tube, which ma^ ^e
pushed into the test tube so as to come immediately over tJiC.
crucible. The coals burn away in a few minutes with very
intense heat, and the hot gases escape through the water, the
bubbles being broken up by pissing through sheets of wire
gauze which stretch between the test tube and the walls of
the vessel containing the water in which it is placed. The
temperature of the water is taken before and after the
experiment, and, from the figures thus obtained, the heating
power of the coal is calculated.
THE DEVELOPMENT OF ELECTRICITY.
There are now about $6,000,000 invested in the manufac-
ture of electric motors in the United States, and this large
investment has nearly all been made within the last three or
four years. It represents either the independent invest-
ment of companies engaged in the exclusive manufacture
of motors, or an increase in the capitalization of companies
that manufacture electric appl'ances, and find the construc-
tion of electric motors a good auxiliary industry. Some
of these companies employ many hundred men, some-
times approaching a thousand, and they turn out motors
almost innumerable each year. These motors are of all sizes,
from one-ha'f horse power, for driving sewing machines and
such other light work, up to several hundred horse power for
heavy work. They are becoming a driving force in almost
every industry, and can be utilized in localities where the cost
of obtaining fuel would almost equal their open ting expenses.
The chief secret of the rapid advance of this new mechanical
agent is found in the flexibility of its resources. Electricity is
not the generator of power, but only the agency for its trans-
mission and distribution, as it is an agent for the transmission
of the human voice over the telephone wire. Through its
resources, power can be distributed to any point, and in
quantities to suit the customer. Steam, water, nir, caloric, or
any known agency for generating power, is either stationary
or' it demands stationary appliances; but electricity is its
messenger boy, its " Puck," who will consent to do its errands
invisibly, and never ask a clay off or the grant of liberty.
Does a lady want an infinitesimal bit of electrical energy to
relieve her boot on the treadle of her sewing machine, it can
be delivered in her room through an iron box not much bigger
than her reticule. Is the restaurant keeper plagued by an
invasion of flies that expel all but the most hungry and least
profitable customers, they can be gently \vafted to the door
by a multitude of revolving fans, and turned out either into
the bright sunlight or the refreshing shower. Everywhere,
anywhere, without a particle of dust, offensive odor or dis-
agreeable noise, the electric motor can be set to work, and,
tvhile it will bring the substance of the thing wanted, it will
leave behind everything that can give offense. The electric
motor has passed its experimental stages, and the day seems
to be rapidly approaching when every house will find sorae-
thing for it to do in lifting burdens from floor to floor, and
performing every possible labor that can be done by machinery.
Manufacturers have not yet begun to construct motors orna«
mented with gold leaf, mother of pearl, and precious stones,
to rock cradles in the nurseries, but these requirements will
come in time.
CHEMICAL OR PHYSICAL TESTS FOR STEEL.
Captain Jones, of the Edgar Thomson Steel Works,
Pittsburg, was in Edinburgh at the meeting of the Union and
Steel Institute, and, when invited to speak, said he could not
let what Mr. Clark had said about the practice of punching
steel plates in America pass without comment. Punching
steel plates was a relic of barbarism, and there was an appro-
priateness about the president's suggestion, to " punch a man
who punched a plate." As to the relative cost of punching
and drilling, he had long since made up his mind about that,
for many years ago, in constructing a roof, he had drilled all
the holes and found it cheaper than punching. With regard
to the use of steel in America, they found boiler-makers,
bridge-makers and many others using it largely. They had
started with physical tests, not chemical analysis, but they
had come to the conclusion that physical tests could be met,
andl yet the metal not be what it should be. The test foi
boiler plates at the Edgar Thomson Works was higher than
thai demanded for the boiler plates of the United States
cruiy»ts, the limit for phosphorus being .035, and manganese,
.350 jier cent, He had seen steel made in America, where
the heftt had been blown for eight minutes, the manganese
being put in cold, and he was of opinion that the reaction
had not taVen place up to the time of sinking. With regard
213
to steel for bridge construction, he considered that not more
than .065 per cent, of phosphorus should be present, and the
manganese should be kept low, as that was the great oxidiz-
ing agent. He would like to see these conditions enforced
by law. In conclusion he wished to impress on his hearers
the necessity for judging steel by chemical tests first, and let-
ting the physical tests be subsidiary to them.
SUGGESTIONS TO STEEL WORKERS.
Messrs. Miller, Metcalf £ Parkin, of Pittsburgh, have
issued a pamphlet on this subject. They draw attention to
the following points :
Annealing — There is nothing gained by heating n. piece
of steel hotter than a bright cherry-red heat ; on the contrary,
a higher heat may render the steel harder on cooling than
would be the case with the heat just mentioned. Besides
this, the scale formed would be granular, and would spoil the
tools to be used in working the metal, and the metal itself
Would change its structure, and become brittle.
Steel should never be left in a hot furnace over night, as
the metal becomes too hot, and is spoilt for after treatment.
Forge Steel — The difficulty experienced in the forge fire is
usually due more to uneven heat than to a high temperature.
If heated too rapidly, the outside of the bar becomes soft,
while the inside is still hard, and at too low a temperature for
treatment.
In some cases a high heat is more desirable to save heavy
labor ; but in every case where a fine steel is to be used for
cutting purposes, it must be borne in mind that every heavy
forging refines the bars as they slowly cool, and, if the smith
heats such refined bars until they are soft, he raises the grain,
makes them coarse, and he cannot get them fine again, unless
he has a very heavy steam hammer at command, and knows
how to use it well.
When the steel is hot through, it should be taken from
the fire immediately, and forged as quickly as possible.
w Soaking " in the fire causes steel to become " dry " and
brittle, and does it very great injury.
Temper — The word " temper," as used by the steelmaker t
indicates the amount of carbon in steel ; thus, steel of high
temper, is steel containing much carbon ; steel of low temper,
is steel containing little carbon ; steel of medium temper is
steel containing carbon between these limits. Between the
highest and the lowest, there are some twenty divisions, each
representing a definite percentage of carbon.
The act of tempering steel is the act of giving to a piece
214
of Steel, after it has been shaped, the hardness necessary for
the work it has to do. This is done by first hardening the
piece — generally a good deal harder than is necessary — and
then toughening it by slow heating and gradual softening until
it is just right for work.
A piece of steel, properly tempered, should always be
finer in grain than the bar from which it is made. If it is
necessary, in order to make the piece as hard as is required,
to heat it so hot that after being hardened it will be as coarse
or coarser in grain than the bar, then the steel itself is of too
low a temper for the desired purpose. In a case of this kind,
the steelmaker should at once be notified of the fact, and
could immediately correct the trouble by furnishing higher
steel.
Heating — There are three distinct stages or times of
heating :
First, for forging ; second, for hardening ; third, for
tempering.
The first requisite for a good heat for forging is a clean
fire, and plenty of fuel, so that jets of hot air will not strike
the corners of the piece ; next, the fire should be regular, and
give a good uniform heat to the whole part to be forged. It
should be keen enough to heat the piece as rapidly as possible,
and allow it to be thoroughly heated through, without being
so fierce as to overheat the corners. Steel should not bj left
in fire any longer than is necessary to heat it through ; and,
on the other hand, it is necessary that it should be hot through
to prevent surface cracks, which are caused by the reduced
cohesion of the overheated parts which overlie the colder
central portion of an irregularly heated piece.
By observing these precautions, a piece of steel may
always be heated safely up to even a bright yellow heat when
there is much forging to be done on it, and at this heat it will
weld well. The best and most economical of welding fluxes
is clean, crude borax, which should be first throughly melted,
and then ground to fine powder. Borax, prepared, in this
way, will not froth on the steel, and one-half of the usual
quantity will do the work as well as the whole quantity
un melted.
After the steel is properly heated, it should be forged to
shape as quickly as possible ; and, just as the red heat is
leaving the parts intended for cutting edges, these parts
should be refined by rapid, light blows, continued until.the red
disappears.
tror the second stnge of heating, for hr.rdenin^;, great
care should be used, first, to protect. the cutting edges and
215
working parts from heating more rapidly than the body of
the piece ; next, that the whole part to be hardened he heated
uniformly through without any part becoming visibly hotter
than the other. A uniform heat, as low as will give the
required hardness, is the best for hardening. For every
variation of heat which is great enough to be seen, there will
result a variation in grain, which may be seen by breaking
the piece ; and for every variation in temperature, a crack is
likely to be produced. Many a costly tool is ruined by
inattention to this point. The effect of too high a heat is to
open the grain — to make the steel coarse. The effect of an
irregular heat is to cause irregular grain, irregular strains and
cracks.
As soon as the piece is properly heated for hardening, it
should be promptly and thoroughly quenched in plenty of the
cooling medium — water, brine, or oil, as the case maybe.
An abundance of the cooling bath, to do the work quickly
and uniformly all over, is very necessary to good and safe
work ; and to harden a large piece safely, a running stream
should be used. Much uneven hardening is caused by the use
of too small baths.
For the third stage of heating, to temper, the first
important requisite is again uniformity ; the next is time.
The more slowly a piece is brought down to its temper, the
better and safer is the operation. When expensive tools,
such as taps, rose cutters, etc., are to be made, it is a wise
precaution, and one easily taken, to try small pieces of the
steel at different temperatures, so as to find, out how low a
heat will give the necessary hardness. The lowest heat is the
best for any steel ; the test costs nothing, takes very little
time, and very often saves considerable loss.
SUCCESSFUL TESTS OF SHEFFIELD STEEL
ARMOR PLATES.
The fourth of a series of trials of steel plates took place
on board the Nettle, at Portsmouth, England, last week.
The plate, which was manufactured by Messrs. Vickers, Sons
& Company, Limited, River Don Works, Brightside, Shef-
field, was of the dimensions and thickness prescribed for
these tests, viz., 8 feet by 6, and 1O)4 inches thick. It was
fired at by a six-inch diameter breech-loading gun, with a
charge of 48 Tbs. of powder and 100 Ibs. shot. The first
shot was a Holtzer hardened steel shot, the point of which
penetrated as far as the wood backing, and was driven out
again by the elasticity of the steel with such force that the
216
shot stuck the bulkhead through which the gun was fired
Only slight cracks were made round the hole made by the
projectile. The second shot, also a Holtzer, did not pene-
trate to the backing, as far as could be seen. It rebounded
in the same way as the first one, and caused a slight crack
at the top end of the plate. The third and fourth Palliser,
98 lb. cast-iron chilled shot, which went to pieces against
the plate, only causing an extension of the crack made by
the second shot ; and the fifth shot, another Holtzer, was
also sent back to the front, after making a slight penetration
in the wood backing. These results are considered as very
Satisfactory by those who witnessed them, the target having
resisted all the shots fired at it, and looking quite able to
resist still further trial. The shot appeared to be of unusually
good steel , as only one seemed seriously distorted by the
work.
WATCH AND LEARN.
This is an excellent motto for every young man to adopt,
and, by a close observance of it, it will prove of great value,
even after he becomes grown up and starts out in business
for himself. There is no surer way of gaining knowledge
than by a careful an I understanding watchfulness of others
in the sani^ Iiii3 of business as yourself. As an apprentice,
you cannot expect to know everything, and the best way to
gain information from others is to show a willingness to
learn ; then they will take an interest in teaching. But if,
as is too often the case, a young man, after he lias been a few
months in a place, pretends to know as much, and sometimes
more, than those much older and more experienced than him-
self, he will not get much information from his fellow work-
men ; neither will he retain their good will for any length of
time, and may expect to have all manner of practical jokes
played upon him. As a journeyman, if you are intelligent,
you will very often have occasion to believe that you do not
know it all, and, in fact, the longer you live and the more
you learn, the more you will find that there is to be learned.
The egotistical and loud man is seldom a perfect man, and is
generally very far from being as near perfection as he would
have others think him. The person who, on a first acquaint-
ance, is anxious to tell you what he knows, and is very free
in givingadvice and information without the asking, generally
exhausts the supply before very long. He who is willing to
listen is generally the one whose source of information is
"broader and of a more durable, valuable and substantial
ki*?d An example may prove the idea to be conveyed more
217
clearly. An employer was in want of a good, practical and
experienced man for a certain class of work. A young
man applied for the position, who was very certain that he
" knew all about the machine," and he was engaged. It was
not long before every man in the shop knew all that he did,
and one very valuable thing that he did not, and that was
that he did not know all that he pretended to. His manner
and braggadacio very soon got most of the men down on
him. They were not disappointed. The new machine
arrived, and was set up ready for operation. The young
man was given a job to be worked ofif, and began operation?
with that self-conscious air of superiority that is generally
apparent in characters of this description. One whole day
he worked at the job, and it was not then in a condition to be
run. Not only that, but he had shown to the men, who, of
course, were secretly watching him, that he knew practically
nothing of the machine. Then he begoi to lay the blame
for the trouble upon others, and asked assistance and
" points " from some of the other workmen. This of course
he did not get, and finally another man was put on the job,
and he was discharged amid the taunts and ridicule of the
others. If the young man had shown good sense when he
first came into the shop ; not been quite so free to tell all he
knew, and had shown a willingness to learn, there was not a
man in the place that would not have gladly assisted him, and
he might have remained in a good position. It sometimes
pays to be ignorant, at least a little modesty is a good thing
to take with you on going to a new place. If you know more
than you pretend, it will soon be found out, and you will be
the gainer; but, if you fail to make good your pretensions, not
only your employer but all your fellow workmen will be
"down on you," and things will be correspondingly
unpleasant.
DEOXIDIZED COPPER.
The advantages to be obtained by the use of copper as
nearly chemically pure as possible, are generally admitted,
whether the metal be used as copper, or in the form of brass,
bronze, or the many other alloys into which it enters. The
Deoxidized Metal Company, of Bridgeport, Conn., claims
that the desired result is secured by the process which is used
in its works. The castings of brass, bronze, etc. , made under
this process, are most excellent, while the sheet copper and
brass, and the wire made, when submitted to careful tests,
show an unusually high degree of strength, copper wire hav-
ing been tested up to 70,000 Ibs. per square inch, tensile
218
strength. The deoxidized metal also possesses the property
of great resistance to acids, so that it can be used for many
purposes where ordinary metal is soon destroyed by the
chemical action. Journal-bearings made from this .metal
have also been tested with very favorable results, while for
bells it is claimed that the tone and quality is much superior
to ordinary brass.
MAKING JAPANNED LEATHER
Japanned leather, generally called patent leather, was first
made in America. A smooth, glazed surface is first given to
calfskin in France. The leather is curried expressly for this
purpose, and parcicular care is taken to keep as free as pos-
sible from grease; the skins are then tacked on frames and
coated with a composition of linseed oil and umber— in the
proportion of 18 gallons of oil to 5 of umber— boiled until
nearly solid, and then mixed with spirits of turpentine to its
proper consistency. Lampblack is also added when the com-
position is applied, in order to give color and body. From
three to four coats are necessary to form a substance to re-
ceive the varnish. They are laid on with a knife or scraper.
To render the goods soft and pliant each coat must be very
light and thoroughly dried after each application.
A thin coat is afterward applied of the same composition,
of proper consistency, to be put on with a brush, and with
sufficient lampblack boiled in it to make a perfect black.
When thoroughly dry it is cut down with a scraper aaving
turned edges. It is then ready to varnish. The principal
varnish used is made of linseed oil and Russian blue boiled
to the thickness of printers' ink. It is reduced with spirits
of turpentine to a suitable consistency to work with a brush
and then applied in two or three separate coats, which are
scraped and pumiced until the leather is perfectly filled and
smooth.
The finishing coat is put on with special care in a room
kept closed and with the floor wet to prevent dust. The
frames are then run into an oven heated to about 175 de-
gress. In preparing this kind of leather the manufacturer
must give the skin as high a heat as it can bear, in order to
dry the composition on the surface as rapidly as possible
without absorption, and cautiously, so as not to injure the
fibre of the leather. It is well nigh impossible to guarantee
the permanency of patent leather, no matter how expensive
or how careful be the preparation, for it has a sad trick of
cracking without any justifiable provocation.
219
HOW TO LACQUER BRASS.
It is strange that not one druggist out of ten knows how-
to compound and put up a first-class lacquer, but depends
entirely on the manufacturer, who, owing to the general lack
of knowledge regarding the matter, often imposes upon their
customers, sending a vastly inferior article. Again, not one
customer in ten knows how to apply lacquer, and the drug-
gist is blamed, when the user's ignorance is the cause of
failure. Let both the dealer and the consumer keep the fol-
lowing constantly in mind when selling or using lacquer :
Remove the last vestige of oil or grease from the goods
to be lacquered, and do not touch the work with the fingers.
A pair of spring tongs or a taper stick in some of the holes
is the best way of holding.
Heat the work sufficiently hot to cause the brush to
smoke when applied, but do not make hot enough to harm
the lacquer.
Fasten a small wire across the lacquer cup from side to
side to scrape the brush on ; the latter should have the ends
of the hairs trimmed exactly even with a pair of sharp
scissors.
Scrape the brush as dry as possible on the wire, making a
flat, smooth point at the same time.
Use the very tip of the brush to lacquer with, go very
slow, and carry a steady hand.
Put on two coats at least. In order to make a very dura-
ble coat, blaze off with a spirit lamp or Bunsen burner, taking
special pains not to burn the lacquer.
If the work looks gummy, the lacquer is too thick ; if
prismatic colors show themselves, the lacquer is too thin. In
the former case, add a little alcohol ; in the latter, place over
the lamp, and evaporate to the desired consistency.
If the work is cheap, like lamp-burners, curtain fixtures,
etc., the goods may be dipped. For this purpose use a bath
of nitric acid, equal parts, plunge the goods in, hung on wire,
for a moment, take out and rinse in cold water thoroughly,
dip in hot water, the hotter the better, remove and put in alco-
hol, rinse thoroughly, and dip in lacquer, leaving in but a few
minutes ; shake vigorously to throw off all surplus lacquer,
and lay in a warm place ; a warm metal plate is the best to
dry. Do not touch till cool, and the job is done. Lac-
quered work should not be touched till cold; it spoils the
polish.
Sometimes drops will stand on the work, leaving a spot.
These drops are merely little globules of air, and can be
avoided by shaking when taken out.
The best lacquer for brass is bleached shellac and alco-
hol ; simply this, and nothing more.
In the preparation of goods for lacquering, care should be
taken to polish gradually, /'. <?., carefully graduate the fine-
ness of materials until the last or finest finish. Then, when
the final surface is attained, there will be no deep scratches,
for, of all things to be avoided in fine work, are deep scratches
beneath a high polish.
THE REAL INVENTOR OF THE BESSEMER PRO-
CESS.
William C. Kelly, inventor of the Bessemer process of
making steel, and who died recently in Louisville, Ky., was
years ago, the proprietor of the Suanee Iron Works and
Union Forge, in Lyon County, Ky. The metal produced at
these works was taken from the furnace to the forge, where
it was converted into charcoal blooms. These blooms had a
great reputation for durability and quality, and were used
principally for boiler plates and metal. It was while making
the blooms at this place that Mr. Kelly made his great inven-
tion of converting iron into Bessemer steel, which Judge
Kelly of Pennsylvania, at the Masonic Temple Theater last
fall, termed the greatest invention of the age. The old pro-
cess of making blooms was very expensive, owing to the
great amount of charcoal required in its transformation, and
Mr. Kelly conceived the idea of converting the metal into char-
coal blooms without the use of fuel, by simply forcing powerful
blasts of atmosphere up through the molten metal. His idea
was that the oxygen of the air would unite with the carbon
in the metal and thus produce combustion, refine the metal,
and, by eliminating the carbon, wrought-iron or steel would
be produced. When he announced his theory to his friends
and to skilled iron workers, they scoffed, and were struck with
astonishment that a man of Mr. Kelly's learning and practical
iron-making knowledge would suggest such an idea as boiling
metal without the use of fuel, and by simply blowing air
through it.
His friends thought him demented, and discouraged him
from wasting his time and money upon any such visionary
scheme. Mr. Kelly was confident that his idea was a good
one, and began making experiments, which he kept up with
varying success for ten years, but the blooms were manufac-
tured without the aid of fuel. It was generally known ae
221
" "Kelly's air boiling process," and was in daily use convert-
ing iron into blooms at his forge. Mr. Kelly's customers
learned finally of the process, and, not understanding it, they
advised him that they would not buy blooms made by any
but the old and established method. This was the first diffi-
culty placed in Mr. Kelly's way, and he was consequently
compelled to carry on his work secretly, which subjected him
to many disadvantages. Some English skilled workmen in
Mr. Kelly's employ were familiar with his non-fuel process,
and went back to England, taking the secret with them.
Shortly after their arrival in Liverpool, Henry Bessemer, an
English ironmaster, startled the iron world by announcing
the discovery of the same process as Mr. Kelly's, and applied
for patents in Great Britain and in the United States. Mr.
Kelly at once made his application for a patent, and was
granted one over Bessemer, the decision being that he was the
first inventor and was entitled to the patent by priority.
The history of this remarkable invention is a lengthy one,
and it is generally admitted by persons cognizant of the facts
in the case that Bessemer' s idea was secured from the English
ironworkers employed by Mr. Kelly. Certain it is, however,
that Mr. Kelly's invention and patents have heaped honors
and wealth upon Bessemer, and he has been regarded as
the greatest inventor of the nineteenth century, and the
proper credit was always accorded him. Mr. Kelly's process
was but barely successful until after it was perfected by Rob-
ert Musshult, a prominent English iron worker. Concern-
ing the claims of the different persons, a prominent iron and
steel manufacturer, the late James Park, of Pittsburg, once
said: " The world will some day learn the truth, and in ages
to come a wreath of fame will crown William Kelly, the true
inventor, and that truth will never be effaced by time."
A NOVEL PLANING MACHINE.
A machine for planing the curved surfaces of propeller
blades, so as to render them of uniform thickness and pitch,
has been invented in England, and is herewith described.
The principal feature is guiding and controlling the tool to
travel on the curved surfaces, by a cast-iron former.
The machine is provided with two tables, which can be
rotated through a given range by a worm-wheel and worm,
so that the inclinations of both tables can be simultaneously
varied, and to an equal degree. One of the tables carries a
cast-iron copy of the back or front of the blade it is desired
to produce, whilst on the other table the actual propeller is
222
secure^ one of its blades occupying a similar position on tfcij
table to that of the copy on the other.
To4r*ure the rigidity of the work, the table on which the
propeller is fixed has its upper surface shaped to correspond
with thh form of the blade on it, and is finally brought to the
exact sh*ipe necessary by a coating of Portland cement. A
cut y% i'i; deep can be taken without springing the blade.
The propeller is also held by being mounted on a duplicate
of the }>ropeller shaft, which is secured to the table. The
cutting iV; done by a tool of the ordinary type, work being
commence) at the top of the blade, and a self-acting
traverse fo \sed to feed the tool toward the boss.
The tool-holder is connected by a system of levers with a
similar holder at the other end of the slide, carrying a
follower, which moves over the copy, and thus guides the
cutting tool. As the boss is approached, the inclination of
the two tables to the horizontal is altered by the worm gear,
so as to limit the necessary vertical motion of the tool. In
this way all the blades of the propeller may be successfully
machined, back and front, and will then be of identical form
and thickness, and set at the same angle to the propeller
shaft.
One of the propellers lately turned out by this machine
was 6 ft. \p. diameter, with an increasing pitch, the mean of
which was 7 ft. 9 in., the thickness in the center of the blades
varying from l/% in. at the top to I in. at the boss. The
breadth was 21 in., and the widest part and the cross section
showed a regular taper from the center line to a knife-edge.
The importance of accuracy and uniformity in the shape
of the blades of propellers for high-speed vessels is now
generally acknowledged, and the machine we have described
promises to form a very useful addition to the plant of a
modern marine engineering establishment.
HOW TO REMOVE RUST FROM IRON.
A method of removing rust from iron consists in im-
mersing the articles in a bath consisting of a nearly saturated
solution of chloride of tin. The length of time during which
the objects are allowed to remain in the bath, depends on
the thickness of the coating of rust ; but in ordinary cases
twelve to twenty-four hours is sufficient. The solution
ought .not to contain a great excess of acid if the iron itself
is not to be attacked. On taking them from the bath, th?
articles are rinsed in water and afterward in ammonia. The
iron, when thus treated, has the appearance of dull silver ;
i>ut a simple polishing will give it its n r.nal appearance.
HOW TO ANNEAL STEEL.
Owing to the fact that the operations of rolling or ham-
mering steel make it very hard, it is frequently necessary
that the steel should be annealed before it can be conven-
iently cut into the required shapes for tools.
Annealing or softening is accomplished by heating steel
to a red heat, and then cooling it very slowly, to prevent it
from getting hard again
The higher the degree of heat the more will steel be
softened, until the limit of softness is reached, when the steel
is melted.
It does not follow that the higher a piece of steel is
heated the softer it will be when cooled, no matter how
slowly it may be cooled ; this is proved by the fact that an
ingot is always harder than a rolled or hammered bar made
from it.
Therefore, there is nothing gained by heating a piece of
steel hotter than a good bright cherry red ; on the contrary,
a higher heat has several disadvantages : if carried too far,
it may leave the steel actually harder than a good red heat
would leave it. If a scale is raised on the steel, this scale
will be harsh, granular oxide of iron, and will spoil the tools
used to cut it. It often occurs that steel is scaled in this way,
and then, because it does not cut well, it is customary to heat
it again, and hotter still, to overcome the trouble, while the
fact is, that the more this operation is repeated, the harder
the steel will work, because of the hard scale and the harsh
grain underneath. A high scaling heat, continued for a
little time, changes the structure of the steel, destroys its
crystalline property, makes it brittle, liable to crack in hard-
ening, and impossible to refine.
Again, it is a common practice to put steel into a hot fur-
nace at the close of a day's work, and leave it there all night.
This method always gets the steel too hot, always raises a
scale on it, and, worse than either, it leaves it soaking in the
fire too long, and this is more injurious to steel than any other
operation to which it can be subjected.
A good illustration of the destruction of crystalline struc-
ture by long-continued heating may be had by operating on
chilled cast-iron.
If a chill be heated red hot and removed from the fire as
soon as it is hot, it will, when cold, retain its peculiar crystal-
line structure; if now it be heated red hot, and left at a
moderate red for several hours; in short, if it be treated as
Steel often is, and be left in a furnace over night, it will be
224
found, when cold, to have a perfect amorphous structure,
every trace of chill crystals will be gone, and the whole piece
be non-crystalline gray cast-iron. If this is the effect upon
coarse cast -irons, what better is to be expected from fine cast-
steel ?
A piece of fine tap steel, after having been in a furnace
over night, will act as fallows:
It will be harsh in the lathe and spoil the cutting tools.
When hardened, it will almost certainly crack; if it does
not crack, it will have been a remarkably good steel to begin
with. When the temper is drawn to the proper color and the
tap is put into use, the teeth will either crumble off or crush
down like so much lead.
Upon breaking the tap, the grain will be coarse and the
steel brittle.
To anneal any piece of steel, heat it red hot; heat it uni-
formly and heat it through, taking care not to let the ends
and corners get too hot.
As soon as it is hot, take it out of the fire, the sooner the
better, and cool it as slowly as possible. A good rule for
heating is to heat it at so low a red that, when the piece is
cold, it will still show the blue gloss of the oxide that was put
there by the hammer or rolls.
Steel annealed in this way will cut very soft; it will harden
very hard, without cracking, and, when tempered, it will be
very strong, nicely refined, and will hold a keen, strong edge.
THE BURSTING AND COLLAPSING PRESSURE
OF SOLID DRAWN TUBES.
The following table gives the bursting and collapsing
pressure of solid drawn tubes:
Collapsing
Difference.
1500
1350
1000
1700
1400
1400
IOOO
1600
In this table it will be noticed that the bursting strength
exceeds the collapsing strength, and that the difference in-
creases with the diameter, as shown in the last column.
Diameter.
-<i/
Bursting
Pressure.
4800
Collapsing
Pressure.
33OO
3/+ '
31/6
d^OO
31 SO
3
45OO
35°°
ix
S2OO
3 CQO
2*4
5OOO
3600
a#.,
tjQOO
4.SOO
2
5900
4900
I*.
s6oo
40CO
225
MINERAL WOOL.
Mineral wool is the name of an artificial product now
used for a great variety of purposes, chiefly, however, as a
non-conductor for covering steam surfaces of whatever char-
acter. It is largely used for this, and the underground steam
pipes of the New York Steam Company are insulated with it.
Mineral wool is made by converting vitreous substances
into a fibrous state. The slag of blast furnaces affords a
large supply of material suitable for this purpose. The
product thus obtained is known as slag wool. For the
reason that slag is seldom free from compounds of sulphur,
which are objectionable in the fiber, a cinder is prepared
from which is made rock wool. These products comprise
the two kinds of mineral wool; they are not to be dis-
tinguished from it, but from each other.
The resemblance of the fibers to those of wool and
cotton has given the names of mineial M^OO! and silicate
cotton to the material, but the similarity in looks is as far as
the comparison can be followed. The hollow and joined
structure of the organic fiber, which gives it flexibility
and capillary properties, is wanting in the mineral fibre.
The latter is simply finely-spun glass of irregular thickness,
without elasticity or any such appendages as spicules, which
would be necessary for weaving purposes. The rough sur-
faces and markings of the fiber can only be detected under a
strong magnifying glass.
Aside from its uses as covering for hot surfaces, it is also
largely employed for buildings. A filling of mineral wool in
the ground floor, say two inches thick, protects against the
dampness of cellar ; in the outside walls, from foundation to
peak, between the studding, it will prevent the radiation of
the warmth of interior, and will destroy the force of winds,
which penetrate and cause draughts; in the roof it will re-
tain the heat which rises through stair-wells, bringing about
regularity of temperature in cold weather ; the upper rooms
will not receive the heat of the summer sun, and store it up
for the occupants during the night, but remain as cool as
those on the floor below ; the water fixtures in bath-rooms,
closets and pantries will not be exposed to extremes of heat
and cold.
Analysis of mineral wool shows it to be a silicate of
magnesia, lime, alumina, potash and soda. The slag-wool
contains also some sulphur compounds. There is nothing
organic in the material to decay or to furnish food and com-
fort to insects and vermin ; on the other hand, the fine fibers
226
of glass are irritating to anything which attempts to burrow
in them. New houses lined with mineral wool will not be-
come infested with animal life, and old walls may be ridden
of their tenants by the introduction of it.
Mineral wool is largely used for car linings, in which
service it reduces the noise of travel greatly. Aside from
those mentioned, it can be applied generally in the arts for
all purposes where a non-conductor or a shield is required,
and ihe experience of several years show that it is both
serviceable and cheap.
NICKEL PLATING SOLUTION.
, According to the Bulletin Internationale de F Electricite%
the following solution is employed for nickel plating by sev-
eral firms in Hainault. It is said to give a thick coating of
nickel firmly and rapidly deposited. The composition of the
bath is as follows:
Sulphate of nickel ; I Ib.
Neutral tartrate of ammonia 1 1 . 6 oz.
Tannic acid with ether 08 oz.
Water 16 pints.
The natural tartrate of ammonia is obtained by saturat-
ing tartaric acid solution with ammonia. The nickel sul-
phate to be added must be carefully neutralized. This hav-
ing been done, the whole is dissolved in rather more than
three pints of water, and boiled for about a quarter of an
hour. Sufficient water is then added to make about sixteen
pints of solution, and the whole is finally filtered. The
deposit obtained is said to be white, soft and homogeneous.
It has no roughness of surface, and will not scale off, pro-
vided the plates have been thoroughly cleaned. By this
method good nickel deposits can be obtained on either the
rough or prepared casting, and at a net cost which, we are
told, barely exceeds that of copper plating.
A NEW ALLOY.
An alloy, the electrical resistance of which diminishes
with an increase of temperature, has recently been discovered
by Mr. Edward Weston. It is composed of copper, man-
ganese and nickel. Another alloy, due to the same investi-
gator, the resistance of which is practically independent of the
temperature, consists of seventy parts of copper, combined
with thirty of ferro-manganese.
227
PROOF OK THE EARTH'S MOTION.
Any one can prove the rotary motion of the earth on its
axis by a simple experiment.
Take a good-sized bowl, fill it nearly full of water and
place it upon the floor of a room which is not exposed to
shaking or jarring from the street.
Sprinkle over the surface of the water a coating of lyco-
podium powder, a white substance which is sometimes used
for the purposes of the toilet, and which can be obtained at
almost any apothecary's. Then, upon the surface of this
coating of powder, make with powdered charcoal a straight
black line, say an inch or two inches in length.
Having made this little black mark with the charcoal
powder on the surface of the contents of the bowl, lay down
upon the floor, close to the bowl, a stick or some other
straight object, so that it shall be exactly parallel with a
crack in the floor, or with any stationary object in the room
that will serve as well.
Leave the bowl undisturbed for a iew hours, and then
observe the position of the black mark with reference to the
object it was parallel with.
It will be found to have moved about, and tohavemoved
from east to west, that is to say, in that direction opposite
to that of the movement of the earth on its axis.
The earth, in simply revolving, has carried the water and
everything else in the bowl around with it, but the powder
on the surface has been left behind a little. The line will
always be found to have moved from east to west, which is
perfectly good proof that everything else has moved the
other way.
WHY THE COMPASS VARIES.
The compass, upon which the sailor has to depend, is
subject to many errors, the chief of which are variation and
deviation ; that is, the magnetic needle rarely points to the
true north, but in a direction to the right or left of north,
according to its error at the time and place. The deviation
of the compass comprises those errors which are local in
their character ; that is, due to the effect of immediately
surrounding objects, such as the magnetism of the ship itself;
this is sometimes very great in an iron ship.
The variation of the compass varies with the position of
the ship, as shown by these curves of variation. Thus, from
Cape Race to New York the variation of the compass changes
from 30° W. to less than 10° W. ; and from Cape Race to
22S
New Orleans from 30° W. to more than 5° E., the line of
no variation being indicated by the heavier double line
stretching from the coast near Charleston down through
Puerto Rico and the Windward Islands to the northeastern
coast of South America.
To illustrate these variation curves more clearly, a chart
has been made ujxm which variation curves are plotted for
.each degree. This illustrates very strikingly the positions
of the magnetic poles of the earth, which do not by any
means coincide with the geographic poles. On the contrary,
there are two northern magnetic poles and two southern; up
north of Hudson's Bay, at the point where these curves
converge, there is one magnetic pole, and another to the
northward of Siberia. Similarly, there are two in the south-
ern hemisphere, an I these four poles of this great magnet,
the earth, are constantly but slowly shifting their positions,
and just so constantly and surely does the magnetic needle
c>bey these varying, but ever-present forces, seldom pointing
toward the pole which man has marked off on his artificial
globe, but always true to the great natural laws to which
alone it owes allegiance. The small figures with plus and
minus signs at various places on this chart indicate the yearly
rate of change of variation, and this rate varies at different
positions on the chart. Thus, near the Cape Verde Islands
it is p'us j90 ; here the variation increases ^ of a minute a
year; farther to the southward, near the South American
coast, it is plus 7^,, an I to the northward, near the Irish
Channel, it is minus 7,*,,-. Fortunately, however, these
changes are STiall and comparatively regu'ar, and their
cumulative effect can be allowed for, when large enough to
make it necessary to do so
COST OF ELECTRIC STREET RAILWAYS.
One of the street railways in New York is about running
its cars to Harlem by an electric motor. Experts engaged
in perfecting the scheme have made an exhibit, showing that
it can be done at a cost of about two-thirds of the amount
required to run over the sane route with horses or cable.
There will be sixteen batteries inclosed in one wagon, which
will furnish sufficient power for two round trips. Sixty
w in operation in the
States. Of the ultimate success, there can be but little
.
electric street railways are now in operation in the United
doubt ; the one question of any special importance upon
which the experts differ is the superiority of any particular
system.
229
KEEPING TOOLS.
Keep your tools handy and in good condition. This applies
everywhere and in every place, from the smallest shop to the
greatest mechanical establishment in the world. Every tool
should have its exact place, and should always be kept there
when not in use.
Having a chest or any receptacle with a lot of tools thrown
into it promiscuously, is just as bad as putting the notes into
an organ without regard to their proper place. If a man
wants a wrench, chisel or hammer, it's somewhere in the box
or chest, or somewhere else, and the search begins. Some-
times it is found — perhaps sharp, perhaps dull, maybe
broken; and by the time it is found he has spent time enough
to pay for several tools of the kind wanted.
The habit of throwing every tool down, anyhow, and in
any way, or any place, is one of the most detestable habits a
man can possibly get into. It is only a matter of habit to
correct this. Make an inflexible end of your life to "have a
place for everything and everything in its place. "
It may take a moment more to lay a tool up carefully
after using, but the time is more than equalized when you
want to use it again, and so it is time saved. Habits, either
good or bad, go a long ways in their influence on men's
lives, and it is far better to establish and firmly maintain a
good habit, even though that haoit has no special bearing
on the moral character, yet all habits have their influence.
Keeping tool? in good order, and ready to use, is as neces-
sary as keeping them in the proper place. To take up a dull
*aw, or a dull chisel, and try to do any kind of work with it,
is worse than pulling a boat with a broom, and it all comes
from just the same source as throwing down tools carelessly
— habit, nothing more or less. To say you have no time to
sharpen is worse than outright lying, for, if you have time to
use a dull tool, you have time to put it in good order.
AN IMPROVED SCREW-DRIVER.
A screw-driver has been made in Philadelphia with the
handle in two parts, said parts being capable of rotating one
upon the other. A stop-pin and pawl limit the movement of
the shank in one direction, while the top of the handle will
move backward without turning the shank. The mechanism
appears to be very similar to the principle of a stem-winding
watch.
23°
THE EFFECT OF MAGNETISM ON WATCHES,
At a meeting of the Western Railway Club, Mr. E. M.
Herr, superintendent of telegraph of the Chicago, Burling-
ton & Quincy Railroad, read the following paper :
A magnet is a body, usually of steel, having the property,
when delicately poised and free to turn, of pointing toward
the north, and of attracting and causing to adhere to its
ends or poles, pieces of iron, steel, and some other substances.
Materials which are attracted by a magnet are called mag-
netic, and it is because the rapidly moving parts of a watch
are in general, made, in part at least, of magnetic material,
that these timepieces are affected by that peculiar force
magnetism.
Were magnetic substances only affected while a magnet
is near them, there would be little difficulty as far as
watches are concerned. Such, unfortunately, is not the
case, as certain materials, steel more than any other, are
not only attracted by a magnet, but become themselves per-
manent magnets when brought into contact with or even in
the vicinity of a magnetized body. It is to the latter prop-
erty of steel, namely, becoming permanently magnetized by
the approach of a magnet without coming in contact in any
way with it, that causes trouble with watches.
Again, a small piece of steel is much more easily mag-
netized than a large one; consequently, the small and deli-
cate parts of a watch are most likely to be affected. These are
found in the balance wheel and staff, hair spring, fork and
escape wheel, and are the very ones in which magnetism
causes trouble on account of the extreme accuracy and reg-
ularity with which they must perform their movements. It
is, in fact, upon the uniformity in the motion of the balance
wheel, that the timekeeping qualities of the watch depend.
In a magnetized watch this wheel, as well as all other
steel parts, become permanent magnets, each tending to place
itself in a north and south line, and also to attract and to be
attracted by the others; all of which, it is hardly nece sary
to add, tends to affect its reliability as a timepiece. How
small a variation in each vibration of the balance wheel will
cause a serious error in the daily rate of a watch, is easily
realized when attention is given for a moment to the number
of double vibrations this wheel makes in 24 hours.
This varies in different watches from 174.000 to 216,000,
and the variation of a single vibration in this number will
cause a greater error than is sometimes found in the best
watch movements. It is therefore true that the variation in
each vibration of the balance wheel of 1-200,000 part of
thetimeof such vibration, or in actual time about the 1-500,-
ooo part of a second, will prevent the watch rating as a
strictly first-class time piece.
I wish to state, however, that there are very few watches
made of ordinary materials which are absolutely free from
magnetism. This may seem like a sweeping statement, but,
after taking considerable pains to verify or disprove of it, I
am convinced that it is substantially correct.
Why this should be so becomes evident when we consider
that a few sharp blows upon a piece of steel held in the di-
rection of a dipping needle suffice to sensibly magnetize it, and
then think of the numerous mechanical operations that have
to be performed upon each small piece of steel in the moving
parts of a watch before it becomes a finished product.
In order to determine, if possible, to what extent
magnetism prevails in watches, I have examined and tested
for magnetism 28 watches carried by persons other than train
or engineer men, with the following result : Three were very
seriously magnetized ; one to such an extent that it could not
be regulated closely ; twenty barely perceptibly affected,
possibly, but the normal amount due to the process of
manufacture, and in but four could no magnetism be
detected.
On account of the steel parts of a locomotive being
magnetized during the process of construction, and by severe
usage in a similar manner to those of a watch, it has been
claimed that the watches of engineers are constantly subjected
to the action of the magnetic forces, and cannot therefore
keep as good time as other watches.
I have examined for magnetism the different parts of a
number of locomotives in actual service, and, although they
were in general found to be magnetic, they are so slightly
charged as to render it almost certain they could have no
influence upon the rate of a watch, and would surely produce
less effect upon it than the originally slightly magnetized
parts of the watch itself. That this amounts to practically
nothing, is proven by the large number of finely rated
watches now in use in which magnetism is apparent.
As proof of the statement that engine-men's watches are
not, as a rule, more highly charged with magnetism than
those of men engaged in other occupations, the watches of
twenty locomotive engineers were tested. Of these none
were found heavily charged with magnetism; but two more
than normal; twelve with a barely perceptible charge, and
in six none could be detected, showing actually less magnet-
232
ism in these than in the twenty-eight watches previously
examined, none of which were carried on a locomotive, a
result probably due to the fact that engineers, as a rule, are
very careful of their watches, and are less apt to bring them
in dangerous proximity to a dynamo than those not con-
cerned in running trains, and in whom a well-regulated watch
is less important. This, I take it, would surely be the case
did they all understand that a watch is likely to be entirely
disabled by bringing it near a dynamo or motor in opera-
tion. It therefore seems important that all to whom Accu-
rate time is a necessity, should be carefully instructed as to
where the danger lies.
So much has recently been written about the magnetiz-
ing of watches that many persons approach any kind of elec-
trical apparatus with caution. Even a battery of ordinary
gravity, or LeClanche cells, is regarded with suspicion,
while a storage battery is thought almost as dangerous as a
dynamo.
Others, on the other hand, do not even know that a
dynamo is dangerous to watches. It should be borne in
mind that it is not electricity which affects watches, but
magnetism, and that magnets are the seats of danger. It is
the powerful electro-magnets in dynamos and motors that
magnetize watches, and not the strong currents of electricity
generated or consumed by them. True, there is a mag-
netic field about every current of electricity, but it is so
very slight that no effect is produced on watches worn in the
pocket.
Having spoken of the evils of magnetism in watches, it
is, perhaps, proper to add a few words regarding its preven-
tion. The best and most certain way to prevent a watch
becoming magnetized is to never allow it to come near a
magnet. Unfortunately, in the present age, this is a diffi-
cult matter, as no one can say how soon they may find it
necessary to be in the vicinity of a dynamo in operation or
be seated in a car propelled by an electro-motor.
The only practical protection to watches from magnetism
of which I have been able to learn consists essentially of a
cup-like casing of very pure soft iron surrounding the works
of the watch, which is known as the anti-magnetic shield.
That this device is a protection from the effects of magnet-
ism upon watches, there can be no doubt, but that it pre-
vents magnetizing under all circumstances, even its inventor,
I believe, does not claim.
It therefore becomes important to know how far our
watches are safe when supplied with this protection, and
23}
wnere to draw the danger line for the protected, as well as
the unprotected watch. In order to throw some light upon
this question, the following tests were made:
First, to disc >ver to whit extent magnetic bodies placed
within the shield were protected from external magnetic
forces ;' second, in how strong a magnetic field it was neces-
sary to place a watch protected by this device to effect its
rate by magnetization.
While no pretense of scientific accuracy or precision was
made in these tests, it is believed they are sufficiently accu-
rate for scientific purposes.
The first test was made by filling an inverted shield half
fall of water, on the surface of which a very light magnetized
steel needle was caused to float. In a similarly shaped cup,
made of porcelain, another needle, in all respects like the
first, was also floated. A horseshoe magnet was then
brought near each, and found to affect each needle equally,
at the following distances : in shield, 6 in. ; in porcelain cup,
13^2 in.
Distance below a 3/^-in. wooden board, upon which shield
and cup were placed, at which needles could be just reversed
by magnet-— in shield, 3^ in. ; in porcelain cup, %% in.
With just enough water to cover the bottom of shield, the
following distances for equal effects were observed : first
'exposure in shield, 8 in. : first exposure in porcelain cup,
20 in. ; second exposure in shield, 12 in. : second exposure
in porcelain cup, 30 inches.
Since the intensity of a magnetic force varies inversely as
the square of the distance, the above results indicate that to
produce like effects, at equal distances, magnetic forces from
five to six times as strong would be required, with bodies
inclosed within the shield, than with those not so protected.
The second test was made with watches of different
makes, all furnished with the shield. Space will not permit
my going into the details of these tests, which extended over
several months. I will only say that they in general con-
sisted in obta' ling the rating and perfoimance of the watch
before and afttr it was exposed to magnetic influences. The
exposure consisted in placing it nearer and nearer to the pole
pieces of a powerful arc light dynamo and bbserving the
rate before and after each exposure. After many tests of
this kind, the conclusion wr.s reached that a watch carefully
and properly shielded could be safely placed not nearer than
4 in. to the pole pieces of a 23 arc light Ball dynamo.
When brought nearer they were without exception magnet-
234
ized to a greater or less degree, the amount depending
largely upon the time of such exposure.
Watches are now being made, however, which it is
claimed are entirely non-magnetic and unaffected by the
strongest magnetic fields met with in practice. -Several
such watches were also examined and tested. They were
furnished with a balance-wheel, hair-spring, fork and escape
wheel made of an alloy of non-magnetic metals in which
palladium is the principal component. The first of these
watches tested was furnished only with a non-magnetic bal-
ance and hair-spring, and had a steel fork and escape wheel.
This watch is instantly stopped when brought near a power-
ful dynamo.
Other movements were then tried, in which all of the
rapidly moving parts were of non-magnetic material. These
could not be stopped by the field magnets of the most
powerful arc light dynamos, although when placed in actual
contact with the pole piece the balance-wheel was seen to
vibrate less freely, probably due to the attraction of the
staff and pivots, which were of steel. The rate of the
watch was not, however, altered by this test.
A hair-spring made of this non-magnetic alloy was als»
delicately suspended in still air and subjected to the- action
of a powerful horseshoe magnet without developing the
slightest observable magnetic effect.
One of our best -known American watch manufacturing
firms is now making a non-magnetic watch on a plan similar
to that just described ; others will probably soon follow,
hastening the day when a watch thoroughly protected or
inherently insensible to magnetism will be as common, and
considered as necessary to the successful keeping of correct
time as 'he adjustment for temperature and position is
already.
HOW BARRELS ARE MADE.
Barrels are now being made of hard and soft wood, each
alternate stave being of the soft variety, and slightly thicker
than the hard-wood stave. The edges of the staves are cut
square, and, when placed together to form the barrel, the out-
sides are even, and there is a V-shaped crack between each
stave from top to bottom. In this arrangement the operation
of driving the hoops forces the edges of the hard stave into
the soft ones, until the cracks are closed, and the extra thick-
ness of the latter causes the inner edges to lap over those of
of tin-1 h..rd-wood staves, thus making the joints dorbly
FACTS ABOUT IRON CASTINGS.
Some experience of the changes of shape which castings
undergo by reason of shrinkage strains is necessary, in order
to proportion them correctly. I have seen numerous massive
and very strong looking castings fracture during cooling, or a
long time afterward while lying in the yard untouched, or
while being machined ; the reason being that excessive con-
traction in one portion had put adjacent parts into a condition
of great tension. By putting an excess of metal into some
vulnerable point of a casting, is introduced an element of
weakness, and almost a certainty of its breaking by reason of
the internal shrinkage strains. It is not the excess of metal
in itself which gives rise to these strains, but the position in
which it is placed relatively to other sections. Thus a lump
of metal cast in juxtaposition to a thinner portion will not
break the latter, so long as it is able to shrink freely upon
itself. But if placed between two thinner portions, it may
fracture them by its shrinkage. Hence the great aim is to so
design castings that all portions thereof thall cool down with
approximate uniformity. A founder learns much from the
behavior of cast-iron pulleys and light wheels. As they are
so light and weak, proportioning must be correctly observed,
and when customers ask fora " good, strong boss" or " strong
arms," the request is one which, if complied with in the
manner described ; that is, by unduly increasing the metal,
will either fracture the pulley or wheel, or bring it near
to breaking limit. In alt castings "strong'* is a relative
term, that form or size being strongest which harmonizes
as regards general proportions. In a light pulley, three
different conditions may exist: i. All parts may cool
down alike, or nearly so ; 2. The rim may cool long before
the arms and boss; 3. The arms and boss may cool before
the rim. in the first case, the pulley will be strong and safe.
In the second, the rim, in cooling, will set rigidly, but the
arms and boss will continue shrinking, each arm exerting an
inward pull on the rim, and various results may follow.
First, the strain may simply cause the arm to straighten;
or, in less favorable conditions, and especially if straight
arms, or arms but slightly curved, be used, the arms may
fracture near the rim, but seldom near the boss. Or, if the
rim be weaker than the arm, fracture will take place, or the
pulley may be turned, and then break. , In the third case, the
arms and boss cooling before the rim, they are compressed
by the shrinkage of the latter, and the arms may then become
fractured, if curved; or, if straight, may prevent the rim from
236
coming inward, and S3 break it. Tn mo"t cases, fracture
occurs from the mass of metal in the boss. Asa single instruct-
live example out of many, I may quote that of a pair of
2ft. 6 in. pulleys, fast and loose, which had been running for
several years, the fast pulley had a boss 6 in. in diameter, the
loose pulley one of 5 in. only, and both were bored to 3 in.
By the accidental falling of a bar of iron, both were broken.
The rim of the fast pulley was at once pulled in, while the
loose pulley remained level at the point of fracture. This
illustrates the presence of tension in the rim, due to the
larger bcss, and this tension had been present, since the pulley
was made. The pulley with the 5 in. boss was probably
much stronger than that with the six in. boss. Tn fast pul-
leys, and in wheels keyed on, the necessary strength around
the key way may be obtained by the use of key way bosses,
without increasing the entire diameter Where large bosses
are unavoidable, as in some deep, double-armed pulleys, or
in spur wheels keyed onto large shafts, shrinkage is assisted
by opening out the mold around the bosses, and removing
the central core, thereby accelerating the radiation of heat,
and further by cooling them with water from a swab brush
when at a low red or black heat. Many a casting is saved
in this way J Vnother method is to split the boss with plates,
and bond or oolt it together afterward. When casting fly-
wheels with wrought-iron arms, the rim is first cast around
the arms and allowed to cool nearly down before the boss is
poured. If the latter were cast at the same time as the rim,
it would set first, and, by preventing the arms from coming
inward, would put tension upon the rim.
Whe.tf aggregations of metal occur in castings, they may,
if the castings be too strong to fracture, cause an evil of
a secondary character, known as " drawing;" in other words,
the metal is put into a condition of internal stress, and
becomes open and spongy in consequence. " Feeding " tends
to diminish this evil; but much can often be done by light-
ening the metal with cores, chambering out, or reducing the
metal massed in certain places by other means. There is a
difference in the behavior of cast-iron and of gun metal, of
which advantage may be taken in small, light castings.
Designs which will not stand in cast-iron or steel will stand
t\ gun metal, hence the latter may be useful in cases of diffi-
culty.
Sharp angles very often lead to fracture. When brackets,
ribs, slugs, etc., are cast on work, the corners should never
be left square or angular, for, if there be much disproportion
237
of metal, fracture will almost certainly commence in the
angles.
I have already alluded to the " straining " which large
plated and heavy castings undergo, so that the sides and
faces increase in dimensions, becoming more or less rounded.
The main reason is, I think, that the metal round the
central portions does not cool so rapidly as that at the
sides. The outsides radiate heat quickly, and shrink to
their full extent; but the middle rib or ribs, and the cen-
tral portions of the plate, retain their heat longer, and
hold the sides in a condition of tension, thus forcing them to
bulge or become round. When the central portions cool,
the outsides are too rigid to yield to the inward pull. This
refers to framed hollow work. When plates " gather " or
increase in thickness, it is due mainly to the lifting of the
cope, from insufficient weighting. When a cubical mass of
metal shows no shrinkage, this is due to the pressure of the
entire mass compressing the sand on every side.
Briefly stated, then, in deciding the proper contraction
allowance for a pattern, I should take into consideration its
mass, the manner in which it is molded and cast, the presence
or absence of cores, and the nature of the same, its general
outline, and the character of the metal. For a heavy solid
casting in iron, I should allow considerably less than t!\e
normal contraction for iron ; for a similar casting in stee],
more than the normal contraction for steel ; for a heavy
casting in gun metal, less than the normal contraction for
gun metal. The precise allowance in any case must be
regulated by circumstances. For the vertical depth of a
shallow casting, very little shrinkage, if any, should be
allowed; for a deep casting, the full amount. Then, again,
a mold, with dry sand cores of moderate or large size, will
not allow the casting to shrink so much as if the cores were
of green sand, or were altogether absent. For hard and
chilled iron, the shrinkage will be at its maximum ; for
strong mottled iron, at its maximum ; and for common gray
metal, at about the average.
FLEXIBLE GLASS.
An article called flexible glass is now made by soaking
paper of proper thickness in copal varnish, thus making it
transparent, polishing it when dry, and rubbing it with pumice
stone. A layer of soluble glass is then applied and rubbed
with salt. The surface thus produced is said to be as perfect
as ordinary srlass
SOME ELECTRIC LIGHT FIGURES.
Now that modern improvements in the methods of dis-
tributing electricity for incandescent lighting have rendered it
practicable to establish and maintain central station plants
at a profit, even in towns of not more than 4,000 inhabitants^
it has become possible to ascertain, with some approach to
accuracy, the dimensions of the field which is open to be oc-
cupied by this incomparable illuminant.
Experience shows, that, when house-to-house lighting has
been thoroughly worked up in any town, the capacity of the
central station plant will need to be equal to an average of
about one-sixteenth candle-power lamp for each inhabitant.
According to the census of 1880 of the 50,000,000
inhabitants of the United States, 13,000,000, or 26 percent.,
resided in 580 towns and cities having a population in excess
of 4,000 each.
At the normal rate of increase, we shall have, in five years
from the present writing, a population of nearly 70,000,000,
of whom some 18,000,000 will be gathered within the limits
of towns of 4,000 inhabitants, and upward. Each of these
individuals will represent one incandescent lamp, and the
necessary power for operating the same. Even after deduct-
ing the lamps which have already been installed, there will be
required a total output of more than u,oco lamps, and over
I,ooo horse-power each of steam engines, boilers and
dynamos, every working day for the next five years, to
supply the demand which, from all present appearances, will
inevitably arise. This is entirely aside from the additional
number of lamps which will be required for renewals — itself
an enormous item. The change from gas to electricity,
which is now going on in connection with domestic lighting,
will be not a little accelerated by the action of the gas
companies, who are everywhere evincing an increasing dis-
position to take up electric lighting themselves ; and a very
sagacious policy it is too, in view of the present outlook for
gas illumination.
TO CLEAN RUSTY STEEL.
Mix ten parts of tin putty, eight parts of prepared buck's
horn, and twenty-five parts of spirit of wine to a paste.
Cleanse the steel with this preparation, a. d finally rub off
with soft blotting paper.
239
HINTS ON PATTERN-MAKING.
The pattern shop is one of the most important depart-
ments in a plant for the manufacture of machinery. It is
here that the plans of the mechanical engineer are first
developed, and upon the skillful manner in w'lich the pat-
terns are constructed and those plans faithfully carried out,
depends much of the future success in the manufacture of the
machine. The skillful pattern-maker, by accurate calcula-
tions for shrinkage, finishing and the contingencies of the
foundry, may save a great amount of labor and annoyance in
the machine shop. It is unreasonable to expect perfect cast-
ings from imperfect patterns, and the molder is often blamed
for imperfections of the castings when the fault may be traced
to an imperfect pattern. Holders as a class have sins
enough of their own to answer for without the addition of
the sins of the pattern-maker. Patterns are as a rule neces-
sarily expensive, and should be carefully constructed, so that
they will retain their shape and proportions for future use,
and to this end the selection of materials and the manner of
joining the several parts together becomes an important item.
For all ordinary purposes, especially for patterns of consider-
able size, good, clear, well-seasoned white pine is the best,
and to obtain the best results it should be seasoned in the
open air in the natural way. The sap of all the woods con-
tains a k.rge percentage of water, and to get rid of
this is the object in seasoning. Pine wood, besides
water, 'contains a large percentage of turpentine in
the sap, and in seasoning it, it is desirable to retain
as much of this as possible, as it dries to a hard substance
when seasoned in the open air, and helps in a measure to fill
up the pores of the wood, and renders it close and more
impervious to water, and less liable to be affected by damp-
ness. Kiln-dried lumber, although extensively used at the
present time, is not as good for this purpose. The heat and
moisture used for this purpose expels, not only the water,
but other ingredients, which leaves the grain open and brash,
and patterns made from such materials are more liable to
absorb dampness and warp than otherwise. In constructing
patterns, especially those of considerable size, it is cus-
tomary to build them up of several pieces glued together;
this makes more reliable work, provided good glue is used
and proper care manifested in the manner of putting
them together. No two pieces should be glued together
with grain crossing at right angles, for, no matter how dry
the lumber may be, there will always be soma shrinkage,
240
and, as lumber shrinks, almost entirely, in its transverse sec-
tion, it is sure to warp, unless the glue gives way so as to
allow each part to shrink in its natural direction. In either
case the pattern will be unfit for further use until it is
repaired. It is not good practice either, to glue up stuff for
patterns with the grain of each piece running parallel with
the other, as such patterns are deficient in strength, and are
liable to split. The most practical way is to arrange the
several pieces so that, when put together, the grain will run
diagonally across each piece, at an angle of about twenty-
five or thirty degrees. Pattern stuff prepared in this man-
ner will have sufficient strength to prevent splitting by use
and handling, and the tendency for warping will, to a great
extent, be avoided. In building up circles, the cants should
be short, and cut lengthwise of the grain as far as possible,
so that the grain of each course as it is laid together to
break points, may cross each other diagonally. It is cus-
tomary with some pattern-makers to use nails or birds in
each course as it is laid up, but pegs made of maple
or hickory are much better, and, when the stuff is suffi-
ciently thin to admit of it, the common pegs used in shoe
shops are very cheap and convenient. The advantage of
using pegs instead of brads or nails i-, that, being driven
in glue, they hold better, and the cants are not as liable to
spring apart when exposed to the warm, damp sand in the
foundry; besides, they never give the workman any trouble
when turning it; and experience has demonstrated that pat-
terns put together in this manner are much more durable
than otherwise. Some pattern-makers use but little judg-
ment in the use of glue, and seem to have an idea that the
more glue they can get between two surfaces the better; yet,
every experienced mechanic knows that exactly the reverse
is the case. With a good joint and clear, fresh, thin glue,
the least that is retained between the two surfaces the bet-
ter and stronger will be the joint. In hot weather glue soon
sours, turns black and becomes rancid; when in this condi-
tion, its strength is impaired and it is unfit for use. Alco-
hol mixed with it will prevent souring, but, as soon as it is
healed up, the alcohol evaporates, and its effects are lost.
The most effective preventive is sulphuric acid, but the
acid should not be applied clear. For an ordinary glue-pot
about fifteen drops of the acid mixed writh a couple of
spoonfuls of water may be applied; while this in no way
impairs the strength of the glue, it will effectually prevent
souring, and keep it fresh and clear.
For small gear patterns that are to be in constant use, cut
patterns of iron or brass are no doubt the best and cheapest
in the end; but, if wood patterns are required, they should be
made of some harder wood than pine ; mahogany or cherry
is considered the best for such work. After the hub is turned
to the proper size and width of face, the blanks for the teeth
may be glued on and dressed in their places.. With large,
wide-faced gears, it is not convenient to do so ; the blanks
for the cogs are usually glued to dovetailed slips, or the
dovetailed formed on the under side of the blank so thatr
when fitted to the rim, or dressed off, and laid out, they max
be removed for the convenience of finish ing them. The
dove-tails should be a perfect fit, and the blank well fitted
to the rim; otherwise they will vary the pitch when dressed
and replaced again. In constructing patterns for heavy
castings, such as lathe and engine beds, the careful and evei?
distribution of metal in each part is an important considers
tion, and, in order to give some particular part the requisite
strength to withstand a heavy strain, it is sometimes necessary
to put more metal in some other part where it is not needed
in order to prevent the casting from being distorted in shape
or cracked by the unequal construction caused by one part
cooling faster than another. With the framework for lighter
machinery the same allowanc * for shrinkage must be provided
for. But where a frame is composed of several parts, some
of which are much lighter than others and yet it is necessary
that the whole should be cast together, it is well to make
the lighter portions in curves as far as the nature of the work
will permit. Shurp edges and square corners should also be
avoided as far as possible. A small cove in each corner will
add much to the convenience of molding, besides adding to
the strength of the casting and insure it against cracks, which
are liable to open at these points by shrinkage in cooling.
The pattern-maker should also exercise good judgment
in making provision for withdrawing the pattern from the
sand; but, as no two patterns are just alike in this respect, no
definite rule can be followed. In intricate patterns, which
require considerable skill and care on the part of the molder
in withdrawing them from the sand, if the nature of the
work will admit of it, considerable more draft should be
allowed for this reason. But plain patterns may be nearly
straight, provided their surface is perfectly smooth. For
much draft, especially with gearing, is very objectionable,
for it is impossible for such gearing to run together
accurately, and bear the whole length of the tooth or
cog, unless they are either chipped and filled, «Dr planed
straight. If gear patterns are made accurate and true,
and the face of the cogs perfectly smooth, there will be
no difficulty in molding them if they are nearly or quite
straight. All patterns before being used should be well
covered with at least two coats of pure shellac varnish.
After applying the first coat, and when it is perfectly dry,
the surface should be well rubbed down with fine sandpaper,
and all imperfections, such as nail holes and sharp corners,
not already provided for, should be carefully filled with bees-
wax and rubbed off smooth before the second coat of var-
nish is applied. After a pattern has once been used, it is
good practice to again rub it off with very fine sandpaper,
and apply another coat of varnish. Many well-made pat-
terns are ruined in the foundry by not being provided with
the proper facilities for rapping and drawing. The molder
Jnust have some means for attaching his appliances for lift-
ing it out, and, if suitable provision is not made for this pur-
pose, he will screw his lifter in any part of the pattern that
is most convenient, and the chances are, that it will split the
first time it is used, or badly marred up. Iron plates should
be let into all patterns with holes threaded to suit his lifters,
and well secured either by screws or rivets, and, if a sufficient
number are attached, the molder will respect the pattern and
use them. Wood patterns should never be allowed to
remain in the foundry; as soon as they are used, they should
be taken to the pattern-room, brushed off and placed in such
a* position for future use that they will not become warped
or sprung.
ELECTRIC HAND LANTERN.
A German patent has been granted to A. Friedlander
for an electric hand lantern. This consists of a box of hard
rubber carrying a small three-candle power incandescent
light, together with a reflector and glass protector. The
elements in the box, carbon and zinc, produce the current
necessary to feed the light. The box is divided into five
compartments holding the liquid, and the electrodes are
placed in such position that r,o decomposition occurs when
the lantern is not in uce, The < irciiit is closed when the
electrodes are dipped in the liquid; the current is stronger
and the li^ht brighter if tlvj electrodes are dipped deeper in
the liquid ; this depth ard consequently the brightness of the
light can be regulated by means of a button on the outside.
The liquid is a combined solution of chloride of zinc, bichro-
mate of soda in wa'er and acid, and the lantern can hold a
sufficient supply of th s solution t^ last for about three hours.
243
TABLES OF GEARS FOR CUTTING STANDARD
SCREW-THREADS.
INTRODUCTION.
It may, perhaps, be necessary to state that these tables
are the fruit of much experience, and a deep-seated convic-
tion that their want is sorely felt by many. Notwithstanding
the vast improvements of modern screw-cutting machinery,
much time is still wasted by the most experienced workmen
in endeavoring to find wheels to but any particular pitch o,
screw, or broken number, in consequence of the various
changes to be obtained from the usual set of screw-cutting
wheels, most of which begin with a 2O-teeth, 25, 30, 35, 40,
45> 5°» 55» 6o» 65» 7°» 75 » 8o» 85> 9°> 95> I00> no, I20> i3°»
140 and 150. This may be considered a full set, inasmuch as
any screw may be cut with it Supposing the ao-wheel to
be put on the mandrel, for single changes, without the pinion,
the first figure up to 95 will give the number of threads to
the inch. A 20 and A 25 will cut 2^ ; 20 and 30, 3 to the
inch, and so on in like ratio. When three figures are on the
wheels, however, the first two will indicate the number to
the inch ; as, 20 and 100 will cut 10 ; 20 and no will cut n;
etc. For many common numbers this will save the trouble
of looking to the tables, if a f£, ^, or other coarse pitch.
If the book be referred to for the decimal of the ratios
required, against it will be found the wheels that will cat it.
If the number be required to the foot, then multiply by tv/elve.
These tables are calculated on the assumption that a pin-
ion of twenty teeth is used, and a driving-screw of two
threads to the inch.
Wheels, when affixed to the mandrel, are r Olcu maadrel-
wheels ; those on the screw, screw-wheels ; ar d those inter-
vening, intermediate-wheels. When the may drel and screw-
wheels are connected by one or more whe .Is directly, they
are termed simple wheels. When attach? ( by means of a
pinion joined to the intermediate wheeJ ' =^ey are calledcom*
pound wheels.
io. I, is a table of sim^i« wneels. The mandrel- wheels
are in the first perpendicular column; and the screw-wheels
in the top horizontal column. In the spaces where the per-
pendicular intersects the horizontal, will be found the pitch of
the thread which any two wheels will cut.
The remaining tables are of compound wheels. The
mandrel-wheels will be found in the first perpendicular column,
the intermediate-wheels in the top horizontal column, and
the screw-wheels in the bottom column. The pitch of thread
244
to be cut having been found in the tables, on the left hand
the mandrel- wheel will be found, on the top the intermediate
wheel, and at the bottom the screw-wheel.
All lathes have not a twenty-teeth pinion, in which case,
the following rule will be of use as applying to any other
pinion :
Multiply the pitch of thread intended to be cut, by the
new pinion, and divide by twenty. Find the wheels in the
tables corresponding with the quotient, and use the new pin-
ion instead of the twenty.
In some lathes the mandrel-wheel is a fixture. In these
instances, suppose the mandrel-wheel to be the pinion, and
attach the mandrel-wheel found in the table to the interme-
diate-wheel.
To ascertain the ratio of any series of wheels, multiply
the whole of the driven wheels together, which will give the
total number of teeth in the series. Then divide the result
by the driving wheels multiplied into each other. The quo-
tient will be the number of times the first wheel will revolve
to the last. Suppose a wheel of twentv teeth to be driving
a. wheel of 100 teeth, to which is attached a wheel of thirty
teeth driving a wheel of 150 teeth, and the ratio be required —
loo X 150
=25 revolutions.
20 X 30
To find the number of threads a set of wheels will cut, multiply the
ratio of the wheels by the pitch of the driving-screw.
To cut double or more threads, divide the mandrel-wheel in as
many parts as you require threads, and, as you cut the screw, shift the
mandrel-wheel a division, while the screw-wheel remains stationary.
This plan will insure equal division and regularity of cutting. In all
lathes where the leading screw is two to the inch, and an equal number
of threads being cut, if the saddled clutch be thrown out of gear, it will
always fall into the right place. If an odd number of threads are being
cut, it will fall right every other one. By attending to this rule, run-
ning the lathe backward will be avoided, and a screw cut in about half
the time.
A difficulty frequently arises in finding the number of threads to the
li.ch or foot when a particular pitch or fractional number has to be
matched. This can easily be ascertained J)y measuring onward, for, if
it do not come right in one inch, notice how many there are between
any division of rule. In measuring a screw, you discover there are
twenty-eight threads in three inches. Consequently, if twenty-eight be
divided by three, it gives 9. 333 as the pitch. Against that number in
the table will be found the wheels to cut it. Suppose a coarse pitch be
required, say one thread in 1^3 inch, the wheels may be found thus:
when there is less than one thread to the inch, see how many there are
in twelve inches: as, 1.615 in- pitch into 12 in. is 7.384101116 foot. If
divided by twelve, we have the dec. .615, against which in th<* table
will be found the wheels.
245
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265
TABLE FOR MAKING THE UNIVERSAL TAPS,
WITH THE MOST SUITABLE PROPORTIONS
REQUISITE FOR GOOD WORKING TAPS
USED BY HAND.
From /4 to j^- the head is turned the same sire as the
screw; the ^j, and all above, to pass through the holes
screwed. As the same table shows the size of tap and bol^-
torn of screw, the workman will be enabled to make the
tapping holes a size that will insure a full thread. The bat-
torn of screw will give the size for drills, bits, etc.
rt S J^ : ^ : §
-
o
Wheels fcj cutting
the screws.
«*- r£ t/) | 'O £o
^.S -5 v- ^
GJO oJ
*0 S,
> 'cL "So o "^ £ ;
t
tH trt
r ;
i
£ p 0- C ~ «
o £ rt <u ~ — '
£ i 2 T ~ ^
i— « =3
r- ^
rt
1 §
1
5 .2j
g.sa
C
.2
i
.S : "c o "3 ! S
5-
rt
.S
o
G . PQ ^ h-!
S
^
^
^
£
CO
1
n-i
20
40
So 20
IOO
-j% X 2/^i Ii&e
TO
1,8
40 80
20
90
^ V an(^ 64 2^4 l%,
"ft
io
45 &°
20
90
Simple wheels.
~ \ ] i i o T 3/
10- 3_^ ' J /
H
H
20
140
I 2
20
1 20
72 .< •/ ^^ A "•"'•5
IB , ":{"•> : : ^5/4 ~ _^ i^:?
20
.
120
2O !
110
{'5 " ',j "| V Ti; ^ ;{,
j j
I IO
in 1 (.'• L . <5 ! ^ -r " ° 4
IOO
ft . , ^ n 4 •_ -_s -'4 am
^ iftaucl (;'i 5 2:^ %
g
20 ... J. ... C)0
i -4 aiul ^,1 ; ^ 3 ;4 "s
&
~J ' ^
1 V J an<^- {?<! ^ ' 2 : ?4 i l
;
20 70
I,H «#;. ^ 7 1 4X1 ' '
..... 00
266
TABLE FOR MAKING THE UNIVERSAL TAPS - (Continued.)
£
T3 <L> i CH
' <3 "o rt - " ? .
« 2 ^ i « . o
-= Wheels
.E for cut ting the
Si
•5 IB "o § 6 • u-
cj screws.
5
Tl t
c "£
^ ^
1 | ! -o
"5 ?
rt
2 t ; 5 I "|> " ! | a 1 |
J §
(U
5
PQ
fe ! ^ ; s • x
S
o
T#
lA
7 1/ 1 4"^ j^ 1 6
20
60
i^
iil 9 i 5,^ ' >s 5
20 50
i^
ii76 and CM 9/2 534 ; ^s I 5
20 i 50
ij^
is*
10 6>4 >4
^
/4 40 90
2
i^ and -J.j
ii
63^
V2
^|
^ 40
90
2/^
i % and 33*
1 1^
?x
'y2
4
l/z 40
90
2X
\y% and 11<;-
12
7&
H
4
40
So
2^
2,/4 ; i2}/2
8^
H
4
40
So
2/^
2,^5 : 13
IO^/
H
4
40
So
2^
2/V • I3 "
9X
Ji
4
40
So
2^
2/8
13/4
9^4
H
3
l/2 ! 40
70
2,%
2^
I3/^
10
1^4
3
K ! 40
70
3
2^
H
10
2
3
K 40
70
UNIVERSAL GAS-PIPE THREADS.
WHEELS FOR CUTTING, ETC.
DIAMETER.
Man-
drel.
Interme-
diate.
Pinion.
Screw.
Pitch.
I#» find all above
i . . .
85
20
So
20
120
IAO
11.294
$£
20
IAO
id.
^o
6c
20
8c
18 412
Small brass tube . .
3o
60
20
120
24.
HOW PUMICE STONE IS MADE.
Pumice stone is now prepared by molding and baking a
mixture of white feldspar and fire-clay. This product is said
to have superseded the natural stone in Germany and
Austria.
26;
NOTES ON THE WORKING OF STEEL.
1. Good soft heat is safe to use if steel be immediately
and thoroughly worked.
It is a fact that good steel will endure more pounding than
any iron.
2. If steel be left long in the fire it will lose its steely na-
ture and grain, and partake of the nature of cast iron.
Steel should never be kept hot any longer than is necessary
to the work to be done.
3. Steel is entirely mercurial under the action of heat,
and a careful study of the tables will show that there must of
necessity be an injurious internal strain created, whenever
two or more parts of the same piece are subjected to dif-
ferent temperatures.
4. It follows that when steel has been subjected to heat
not absolutely uniform over the whole mass, careful anneal-
ing should be resorted to.
5". As the change of volume due to a degree of heat in-
creases directly and rapidly with the quantity of carbon
present, therefore high steel is more liable to dangerous in-
ternal strain than low steel, and great care should be exer-
cised in the use of high steel.
6. Hot steel should always be put in a perfectly dry jilace
of even temperature while cooling. A wet place in the floor
might be sufficient to cause serious injury.
7. Never let any one fool you with the statement that his
iteel possesses a peculiar property which enables it to be
" restored " after being " burned;" no more should you waste
any money on nostrums for restoring burned steel.
We have shown how to restore " overheated " steel.
For " burned " steel, which is oxidized steel, there is only
one way of restoration, and that is through the knobbling fire
or the blast furnace.
" Overheating " and " restoring " should only be allowable
for purposes of experiment. The process is one of disintegra-
tion, and is always injurious.
8. Be careful not to overdo the annealing process; if car-
ried too far it does great harm, and it is one of the commonest
modes of destruction which the steelmaker meets in his daily
troubles.
It is hard to induce the average worker in steel to believe
that very little annealing is necessary, and that a very little
is really more efficacious than a great deal.
268
WEIGHT AND NUMBER OF SQUARE NUTS IN A
BOX OR KEG OF 200 POUNDS.
Width.
Thick-
ness.
Hole.
Size of
Bolt.
No. in
200 Ibs.
Weight
of Nut.
yz
X
7-3^
X
14,844
Ibs.
e/
5-16
Q-^2
7,'88o
V
11-^2
•M?
4,440
*A
7*16
o**
I 3-32
7-16
2,772
s°
/
7-16
/ *
5 / d
2,45°
1
i/
7-16
c /*
1,816
Jl/
y
/
Q- 16
1,^00
*1A
X
79-i6
| c/
13 j
M74
•*7
*X
H
9-16
j- /8
898
•23
\$
X
21-32
I v
662
•3
H
21-32
i M
538
•37
1$
7A
25-32
1
392
.51
i%
7A
25-32
C /»
326
.61
1$.
i
X
3<>4
.66
2
i
y%
r*
224
.89
2
i/^
15-16
214
•93
*X
\1A
15-16
r 1%
152
1-32
2X
\%
1-16
1 I/
143
1.4
9.Yz
l%
1-16
y J/4
108
1.85
*X
ift
3-16
*H
83
2.41
3^
i/4
5-16
I//2
65
iH
7-16
1^4
4-
3%
*
9-16
i%
42
4-8
3/4
11-16
ij4
32
6-3
4
2
13-16
2
27
7-4
2 V$2
i ^
21A
7 3xf
A1/
2y
2
t'/O
gl/
A\/
2y
2*A
8^/
4/4
AJ4
I/
2.V
21A
io3/
<f/Z
2y
2 7-l6
fif.
2*2
j^i/
5
3
/ *
2 II-I6
*v*
3
14
AMOUNT OF HEAT REQUIRED TO MELT
WROUGHT IRON.
The temperature necessary to melt wrought iron lies
between 4,000° and 5,000° F., and ev«m at that tremendous
heat, wrought iron is only rendered fluid by the addition of a
small amount of aluminum.
269
WEIGHT AND NUMBER OF HEXAGON NUTS
A KEG OR BOX OF 200 POUNDS.
Width.
Thick-
ness.
Hole.
Size of
Bolt.
No. in
200 Ibs.
Weight
of Nut.
X
X
7-32
X
17,332
IbflL
5^
C- 16
Q-^2
K- 16
8,964
v
li
y
5,016
7A
7 /•
7-16
I V^2
7-16
2,988
7A
7-16
1
2,674
if 9
/!
' -
7-16
c
' 4T
2,160
>0
I/.
9-16
Q-l6
I.44.C
J
9-16
j '
^x
* J^Tj
I ',028
'?
X
^
9-16
\
920
.22
!i8
»
21-32
21-32
\ y*
752
510
:S
i^
$
25-32
} 7/
450
•44
ij^
25-32
\ '8
428
•47
iS
#
I
}'
37|
336
:l4
2
^
15-16
/^
211
•95
2#
Xs
"
1-16
X
159
1.26
2^
3-16
^
119
1.68
5-16
l/z
88
2.27
3
^
7-16
y%
69
2.9
1^
9-l6
i^
56
3-6
3K
2
11-16
\y%
44
46
3^
2
13-16
u
43
4-7
4
2
13-16
i2
29
6.9
l3a
2 V^
~/K
2 V^
c %
'y
2\A.
2
•2y
/
4.
234
6y
.y
2*/2
2I/
2i/
~i/
41A
2*2
2 7-16
2X
gL/
/
*•/•*
3
3
I!5_
HOW TO PREVENT GEAR TEETH FROM BREAKING.
Gear teeth generally have one corner broken off first, after
which they rapidly go to pieces. This may be avoided and
the teeth made much stronger by thinning down the edges
with a file, thereby bringing the whole strain along the centre
of the tooth. jear teeth fixed this way will not break unless
the strain be sufficient to br-sak off the whole tooth.
2JO
NUMBER OF LIGHTS OF WINDOW GLASS IN A
BOX OF 50 FEET.
Size.
No.
Lights.
Size.
No.
Lights.
Size.
No.
Lights.
6x 8
I50
28
16
5°
5
7x 9
Sxio
90
30
18x22
18
30x38
40
I
II
82
24
17
42
6
12
75
26
16
44
6
13
69
28
H
46
5
14
64
3°
48
5
9x12
67
32
13
50
5
13
62
20x26
H
52
5
H
57
28
13
54
4
15
53
30
12
32x40
6
10x13
56
32
II
42
H
52
34
II
32x44
5
15
48
36
10
46
s
16
45
22x28
12
48
11x14
47
30
II
5°
5
15
44
32
10
52
4
16
41
34
10
54
4
18
39
36
9
56
4
12x15
40
38
9
34x44
5
16
38
24x30
10
46
5
18
34
32
10
48
5
20
3°
24x34
9
5°
4
13x16
35
36
9
52
4
18
31
38
8
54
4
20
28
40
8
56
4
22
14X18
25
29
26x32
.34
I
£
4
4
20
26
8
36x46
4
22
24
38
7
48
4
24
22
40
7
50
4
ISXI8
27
42
7
52
4
2O
24
44
6
54
4
12
22
28x36
7
56
4
24
26
20
19
38
40
7
7
58
36x60
3
3
16x20
23
42
6
62
3
22
21
44
6
64
3
24
19
^46
6
38x46
4
26
17
48
5
48
4
NUMBER OF LIGHTS OF WINDOW GLASS IN A
BOX OF 50 FEET.-Continued.
Size.
No.
Lights.
Size.
No.
Lights.
Size.
Na
Lights
5°
4
60
3
66
3
52
4
40x62
3
68
54
4
64
3
70
a
Co
3
66
3
44*54
3
58
3
40x68
3
5S
3
60
62
3
3
70
42x50
3
3
II
3
3
64
3
52
3
62
3
66
3
54
3
64
3
40x48
4
56
3
66
2
50
4
58
3
68
2
52
3
60
3
70
2
54
3
62
3
72
2
56
3
64
3
COMBUSTIBILITY OF IRON PROVED.
Combustion is not generally considered one of the prop-
erties of iron, yet that metal will, under proper conditions,
burn readily. The late Professor Magnus, of Berlin, Ger»
many, devised the following method of showing the combus-
tibility of iron : A mass of iron filings is approached by a
magnet of considerable power, and a quantity thereof is per-
mitted to adhere to it. This loose, spongy tuft of iron pow-
der contains a large quantity of air imprisoned between its
particles, and is, therefore, and because of its extremely com-
minuted condition, well adapted to manifest its combustibil-
ity. The flame of an ordinary spirit lamp or Bunsen burner
readily sets fire to the finely divided iron, which continues to
burn brilliantly and freely. By waving the magnet to and
fro, the showers of sparks sent off produce a striking and
brilliant effect.
The assertion that iron is more combustible than gun-
powder, has its origin in the following experiment, which is
also a very striking one: A little alcohol is poured into a
saucer and ignited. A mixture of gunpowder and iron filings
is allowed to fall in small quantities at a time into the flame
of the burning alcohol, when it will be observed that the iron
will take fire in its passage through the flame, while the gun-
272
powder wPl fall through it and collect beneath the liquid
alcohol below unconsumed. This, however, is a scientific
trick, and the experiment hardly justifies the sweeping asser-
tion that iron is more combustible than gunpowder. The
ignition of the iron under the foregoing circumstances is clue
to the fact that the metal particle- being admirable con-
ductors of heat, are able to absorb *,<_" x-nt heat in their
passage through the flame — brief as this K. -mid they are
consequently raised to the ignition point. The ± 'nicies of
the gunpowder, however, are very poor conductors ^. '-eat,
comparatively speaking, and, during the exceedingly brief
time consumed in their passage through the flame, they do
not become heated appreciably, or certainly not to their point
of ignition. Under ordinary circumstances, gunpowder is
vastly more inflammable than iron.
Another method of exhibiting the combustibility of iron,
which would appear to justify the assert ion that it is really
more combustible than gunpowder, is the following: Place
in a refractory tube of Bohemian glass a quantity of
dry, freshly-precipitated ferric exide. Heat this oxide to
bright redness, and pass a current of hydrogen through the
tube. The hydrogen will deprive the oxide of its oxygen,
and reduce the mass to the metallic state. If, when the
reduction appears to be finished, the tube is removed frcin
the flame, and its contents permitted to fall out into th~ air
it will take fire spontaneously and burn to oxide again.
This experiment indicates that pure iron, in a state of the ex-
tremest subdivision, is one of the most combustible sub-
stances known — more so, even, than gunpowder and other
explosive substances which require the application of con-
siderable heat, or a spark, to ignite them.
HOW IRON BREAKS.
Hundreds of existing railway bridges which carry twenty
trains a day with perfect safety would break down quickly
with under twenty trains an hour, writes a British civil en-
gineer. This fact was forced on my attention nearly twenty
years ago, by the fracture of a number of iron girders of
ordinary strength under a five-minute train service. Simi-
larly, when in New York last year, I noticed, in the case of
some hundreds of girders on the elevated railway, that the
alternate thrust and pull on the central diagonals from trains
passing every two or three minutes had developed a weak-
ness which necessitated the bars being replaced by stronger
ones, after a very short service. Somewhat the same thing
273
I ':. tc be done recently with a bridge over th^ river Trent,
but, the train service being small, the life of the bars was
measured by years instead of months. Jf ships were always
among great waves the number going to the bottom would
be largely increased. It appears natural enough to every one
that a piece, even of the toughest wire, should be quickly
broken if bent back and forward to a sharp angle; but, per-
haps, only to locomotive and marine engineers does this ap-
pear equally natural that the same results would follow in
time if the bending were so small as to be quite imperceptible
to the eye. A locomotive crank axle bends but one eighty-
fourth of an inch, a straight driving-axle a still sn.aller
amount, under the heaviest bending stresses to which they
a: e subject, and yet their life is limited. During the year
1883 one iron axle broke in running, and one in fifteen was
renewed in consequence of defects. Taking iron and steel
axles together, the number then in use on the railways of the
United Kingdom was 14,847, and of these 911 required
renewal during the year. Similarly, during the past
three years, no less than 228 ocean steamers were disabled
by broken shafts, the average safe life of which is said to be
about three or four years. Experience has proved that a
very moderate stress, alternating from tension to compres-
sion, if repeated about 100,000,000 times, will cause a frac-
ture as surely as bending to an angle only ten times.
VALUE OF EMERY WHEELS.
The increased quantity and quality of work that goes on*
of the modern machine shop is clue to the skillful use of solid
emery wheels. A grain of sand from the common grind-
stone, magnified, would look like a cobble stone, a fracture
of which shows an obtuse angle, wnereas a grain of corun-
dum or emery would look lik^ a rhomboid, always break-
ing with a square or concave fracture. No matter how much
it is worn down in use, it does not lo.se its sharpness ; hence
it is evident that the grindstone rubs or grinds and heats
the work brought in contact with it, while the corundum, or
emery wheel, *"ith its sharp, angular grit, cuts like a file or
angular saw.
There are two general classes of emery wheels in the
market — one class of wheels has the grains of emery joined
and consolidated by a pitchy material, as rubber, linseed oil,
shellac, etc. These must run at a high speed to burn out the
cementing material by friction, loosening the worn-out grains,
and thus revealing new cutting nnirk-s. The>e ar.; non-i - n its
274
wheels. Truing up this class of wheels is done with a dla»
moml tool.
The other class consists of two kinds, one made by mix-
ing the emery with a mineral cement and water into a paste,
whit h will harden and bind the grains together ; the other
kind, by mixing the emery with a mineral flux or clay, mold-
ing into shape, and burning in a muffle at a high tempera-
ture. These are porous wheels, in which the grains of emery
are held together by matter having affinity therefor. This
class of wheels, unlike the grindstone, has sharp grains of
emery bedded together among matter which, in some cases,
is as hard and sharp as the emery itself. Such wheels cut
very greedily, and do not need to be run at any particular
speed.
The dresser, made of hardened steel picks, is the proper
tool for truing up this class of wheels.
Manufacturers in metal goods aiming at reducing the cost
of production, would do well to look into the adaptability of
the solid emery wheels or rotary file, and other labor-saving
machinery, before deciding on reducing labor wages.
THE SECRET OF CAST STEEL.
The history of cast steel, remarks a contemporary, pre-
sents a curious instance of a manufacturing secret stealthily
obtained under the cloak of an appeal to philanthropy. The
main distinction between iron and steel, as most people know,
is that the latter contains carbon. The one is converted into
the other by being heated for a considerable time in contact
with powdered charcoal in an iron box. Now, steel thus
made is unequal. The middle of a bar is more carbonized
than the ends, and the surface more than the center. It is,
therefore, unreliable. Nevertheless, before the invention of
cast steel, there was nothing better. In 1760 there lived at
Attercliffe, near Sheffield, a watchmaker named Huntsman.
He became dissatisfied with the watch-spring in use, and set
himself to the task of making them homogeneous. "If,"
thought he, " I can melt a piece of steel and cast it into an
ingot, its composition should be the same throughout." He
succeeded. His steel soon became famous. Huntsman's
ingots for fine work were in universal demand. He did not
call them cast steel. That was his secret. About 1780 a
large manufactory of this peculiar steel was established afc
Attercliffe. The process was wrapped in secrecy by every
means within reach. One midwinter night, as the tall chim.
nevs of the Attercliffe steel works belched forth their sir.oke
275
a traveler knocked at the gate. It was bitterly colcl, and the
snow fell fast, and the wind howled across the moat. The
stranger, apparently a plowman or agricultural laborer seek-
ing shelter from the storm, awakened no suspicion. Scan-
ning the wayfarer closely, and moved by motives of humanity,
the foreman granted his request, and let him in. Feigning
to be worn out with cold and fatigue, the old fellow sank
upon the floor, and soon appeared to sleep. That, however,
was far from his intention. He closed his eyes apparently
only. He saw workmen cut bars of steel into bits, place
them in crucibles, and thrust the crucibles into a furnace.
The fire was urged to its extreme power until the steel was
melted. Clothed in wet rags to protect themselves from the
beat, the workmen drew out the glowing crucibles and
poured their contents into a mold. Mr. Huntsman's factory
had nothing more to disclose. The secret of making cast
Steel had been discovered.
IRON AND STEEL MAKING IN INDIA.
Indian Engineering, in a recent issue, gives a most
interesting account of the manufacture of iron and steel in
India, which we reproduce below:
Notwithstanding the simplicity of their processes, the
iron turned out by the natives is of superior quality, and is
selling very cheaply; so, for instance, a mound of horseshoes
sells at Rs. seven, and of clamp iron Rs. six-eighths. These
low prices are accounted for by cheap fuel, the rich ores, the
miserably cheap labor, and the absence of managing expenses.
There are reasons to believe that "Wootz" (Indian
cast steel) has been exported to Asia Minor more than 2,000
years ago; how long, however, its manufacture has been
commenced, cannot be traced.
The following is a description of the method for making
" Wootz" employed by the natives at Hyderabad.
The minute grains or scales of iron are diffused in a
sandstone-like gneiss or mica schisti passing into a horn-
blende slate. These rocks are excavated with crowbars, and
then crushed between stones; if hard, this is done after prelim-
inary roasting.
The ore is then separated from the powdered rock by
washing. This was at a village called Dundurti, but the pro-
cess of manufacture was ths same as that at Kona Samun-
drum, twelve miles south of the Godavari, and twenty-five
from Nirmal, which has been described by Dr. Voysey. The
furnace was made of a refractory clay, derived from deccm-
276
posed granite, and the crucibles are made of the same, ground
t« a powdei together with fragments of old furnace and
broken crucibles kneaded up with rice, chaff and oil. He
states that no charcoal was put into the crucible, but some
fragments of old glass slag were. A perforation was made
^n the luted cover. Two kinds of iron, one from Mirtapalli
and the other from Kondaporc, were used in the manufacture
of the steel. The former was made from magnetic sand,
and the latter from an ore found in the iron clay (? laterite)
twenty miles distant; the proportions used of each were
3 to 2.
This mixture being put into, the crucible in small pieces,
the fire was kept up at a very high heat for twenty-four hours
by means of four bellows, and was then allowed to cool
down. Cakes of steel of great hardness, and weighing on the
average i% Ibs., were taken from each crucible. They were
then covered with clay and annealed in the furnace for twelve to
sixteen hours; then cooled, and, if necessary, the annealing was
repeated till the requisite degree of malleability had been
obtained. The Telinga name for thi> steel was " Wootz,"
and " Kurs" or cake of it, weighing 1 10 rupees, was sold on
the spot for eight annas. The daily produce of a furnace
was 50 seers, or in value Rs. 37.
Also Mysore is a country where the manufacture of iron
and steel by the natives was of great importance owing to the
excellent quality of its produce.
_ The iron was made from black sand, which the torrents,
formed in the rainy season, brought down, from the rocks.
The furnaces in the Chin-Narayan Durga taluk were on a
small scale", the charge of ore being 42^ pounds, from which
about 47 per cent, of the metal was obtained. Work was
carried on for only four months, the smelters taking to culti-
vation du- ing the remainder of the year. The stone ore was
smelted in the same way as the iron sand, but the latter, it is
said, was alone fit for manufacturing into steel. There were
in this vicinity five steel forges, four in the above taluk, and
ODe at Devaraya, Durga.
The furnace, of which a figure is given by Buchanan, con-
sisted of a horizontal ash-pit and a vertical fire-place, both
sunk below the level of the ground. The ash-pit was about
three-fourths of a cubit in width and height, and was con-
nected with a refuse pit into which the ashes could be drawn.
The fire-place was a circular pit, a cubit in width, which was
connected with the a>h-pit, being from (he surface of the
ground to the bottom two cubits in depth. A screen or mud-
wall five feet high, protected the bellows-man from heat and
277
sparks. The bellows were of the ordinary form, a conical
leather sack with a ring at the top, through which the opera-
tor passed his arm.
The crucibles, made of unbaked clay, were conical in form,
and of about one pint capacity. Into each a wedge of iron
and three rupees' weight of the stem of the Cassia Auricu-
la ta and two green leaves of a species of convolvulus or Jpo~
maia were put. The mouths of the crucibles were then
covered with round caps of unbaked clay, and the junctures
well luted.
They were then dried near the fire, and were ready for the
furnace. A row of them was first laid round the sloping
mouth jof the furnace; within these another row was placeci.
and the center of the dome, so formed, was occupied by *
single crucible, making nfteef. \\\ ic!l
The crucible opposite the bellows was then withdrawn,
and its place occupied by an empty one, which could be
withdrawn in order to supply fuel below. The furnace, being
filled with charcoal, and the crucibles covered with the same,
the bellows were plied for four hours, after which the opera-
tion was completed. When the crucibles were opened, the
steel was found melted into a button with n sort of crystalline
structure on its surface, which showed that complete fusion
had taken place. These buttons weighed about twenty-four
rupees. There were thirteen men to each furnace, a head
man to make and fill the crucibles, and four relays of three
men each, one to attend the furnace, and two for the bel-
lows.
Each furnace manufactured forty-five pagodas' worth of
1, 800 wedges of iron into steel. The net profit was stated
to be 1,253 fanams, but into the further details as to cost it
is not, perhaps, necessary to enter. The total production of
steel in this vicinity was estimated to be 152 cwt., or about
,£300 per annum.
The principal sources of the ores were the magnetic sand
found in rivers, and the richer portion of the laterite.
THE SWISS PATENT LAW.
The Republic of Switzerland has passed a law for the pro-
tection of inventions, thus following in th<? wake of other'
nations. The final disposition of the question, however, as to
whether the law shall be operative or not, %vill first require the
petitions of 30,000 voters asking its submission to the people.
That point gained, the law must then be submitted to a vote
and be approved by a riajoritv Tf, is not stated whether the
278
Swiss Government has a patent on this method of giving a law
force. It will take three months to carry out this rigmarole.
Material objects, and not processes, are protected. It is said
that " this feature is due to the efforts of the manufacturers of
aniline colors and chemicals, whose interests would be inju-
riously effected by a law as comprehensive as that of the United
States, which protects 'useful arts' and ' compositions of mat-
ter,' as well as tools and machines."
HOW BREAKS IN SUBMARINE CABLES ARE
DETECTED AND REPAIRED.
The following is an account of how submarine cables are
found and repaired at an immense depth:
The break, which the " Minia " was sent to repair,
occurred early last summer. The officers of the company
first located the distance of the break from the stations on
shore, on each side of t:\e ocean. The details of the instru-
ment by which this is done nre not easily described, though
easily understood in principle. The machine consists of a
series of coils of wire, which offr a known resistance to the
electric current. Enough of the coils are connected to make
a resistance equal to the resistance offered by the entire cable
when it is in work ing order, and thus, when the machine and "
the cable are connected, a balance is effected. But, if the
cable should break, the balance is destroyed, because that
portion of the cable between the shore station and the break,
wherever it may be, will offer less resistance to the electric
current than the entire cable would do. Enough coils of wire
are therefore disconnected from the machine to restore the
balance. The resistance of the part of the cable that
remains intact is thus accurately determined by the number
of coils remaining connected with the machine. Having,
when the cable was intact, learned the resistance which a
mile of the cable offers, by dividing the entire resistance by
the number of miles of cable, it is easy to find how many
miles of cable are still in good order, by dividing the entire
resistance of the piece by the known resistance of one mile
Having determined how many miles from the shore
station the break is, orders are sent to go to the place, pick up
the ends, and splice them to new piece. Having received such
an order and acted on it, Captain Trott found himself and
his ship, on July 25th last, in latitude 42° 30' north, and
longitude 46° 30' west, or just to the eastward of the Grand
Banks of Newfoundland, with one of the hardest jobs
before him that he had had in some time, for sounding
showed that the water was about 13,000 feet, or a good deal
more than two miles deep. He knew he was somewhere
near the break in the cable, but he did not know absolutely
within about three or four miles, because, while he had been
able to determine his own position by repeated observations
of the sun and stars, he could not tell how accurate the
observations of the officers of the ship laying the cable ^ad
been.
The first work done was to get a scries of soundings over
u patch of the sea aggregating twenty-five or thirty sd1— "«*
miles. The sounding apparatus consisted of an oblong sncn
of iron, weighing about thirty-two pounds, attached to a
piano forte wire in such a way that, when lowered to the bottom,
the shot would jab a small steel tube into the mud down
there, and would then release itself from the wire, and allow
the sailors' to draw up the tube with the mud in it. The
moment the weight was released, the men on deck stopped
paying out the wire, and thus, knowing how much wire had
been run out, they were able to tell the depth. It is a fact
that it took twenty-four minutes and ten seconds for the
weight of the ounding apparatus to reach bottom in 2,097
fathoms of water.
The ship was now ready to begin the search proper for
the cable. She was run off at right angles to the line of the
cable for r. distance of five miles, and a buoy got down to
mark the limits of the territory to be grappled ov-r in that
direction. Buoys were afterward ret elsewhere to mark the
other limits of the territory. The grappling iron was low-
ered over 'he bows, the rope attached to it passing o.ver one
of the three big grooved wheels that revolve where the bow-
sprit of an ordinary vessel stands.
The grappling iron used is the invention of Captain Trott.
It looks something like a four-pronged anchor. It has a shaft
four feet long, and four arms about a foot long, that are set
at right angles to each other at the bottom of the shaft.
Right in each crotch formed by the arms is a little button
that has a spring behind it that may be regulated in strength.
The button projects a third of an inch into the crotch. The
angle of the arms with the shaft is so small that a rock could
not get down in so far as to reach the button ; but, when the
cable is caught by the hooks, it presses down against the but-
ton, and thus closes an electrical circuit through a copper
wire running through the grapnel's rope and the grapnel
itself, and a bell is set ringing upon deck. But the experi-
enced m n in charge of the grappling are generally able to
telJ who ; the hook has hold of without the aid of the bell.
2 So
They judge by the strain on the rope, which is indicated by a
dynamometer on deck. The ordinary strain on the dyna-
mometer is from 3 to 3^ tons when the grapnel is dragging
freely over a smooth bottom as the vessel forges slowly ahead.
Sometimes a rock catches on the hooks. This frequently
breaks off an arm, but sometimes it fetches clear, the strain
indicated by the dynamometer informing the old sailor man
in charge whether an accident has happened or not.
It took two hours and twenty minutes to get the grap-
pling iron from the bow of the ship down to the bottom of the
sea, 13,000 feet below. The cable used to drag it with is the
patent wire and hemp invention of the captain. The drag-
ging began on July 25th, the clay of arrival, but they swept
backward and forward over the territory for ten days without
finding the broken telegraph cable. A good part of .the time
they wt re steaming back and forth d.iy and night, and the
only time when they were not doing so was when the weather
was too bp'-l. On such occasions they went to the buoy at
the supposed end of the broken cable, and hove to till the
gale was ended.
Finally, on August 5th, the bell rang, indicating that the
grapnel had caught the cable. The grapnel drag rope was
thereupon fastened to a buoy and thrown overboard. Then
the steamer went off two miles toward the end of the broken
cable and got out a cutting grapnel. This is like the other
one, except that there are knives in the crotches. When
these crotches catch the cable and strain comes on them, th_
cut the cable off clean.
" Why did you cut off the cable there? " was asked.
" Because, if we had tried to get up the bight of the cable
where we first found it, the cable might have broken under
the strain. That cable was laid in 1869, and is getting
pretty well along in years. It would have been as apt to
break on the shore side as the other, but, when we had only
an end of two miles to deal with, we were sure of being able
to get up without damage. We grappled European end first."
Having cut off the cable, the vessel returned to the buoy
on the grappling rope, and, getting the rope inboard again,
led it to a drum six feet in diameter located on the uppel
deck and operated by a steam engine. Then they began to
wind in the grapnel rope and hoist the old cable to the bows.
They started the drum at 1:20 in the afternoon of August 5,
8x1 at 7:51 had the bight of it at the bow of the ship. Then
the two miles and odd of end that was hanging down from
the bow was fished up and stretched in lengths along the
deck until the end was reached This was connected uirh a.
28l
very complete cable telegraph office located amidships, and
a second later the operators who had been on watch for days
in the British station awaiting this event saw the {lashes on a
mirror in their fftce that told them all about it.
Sometimes it happens that, when an end of the cable is
picked up in this way, and an attempt is made to communi-
cate with the shore, it is found that there is another break,
and that they have only the end of an odd section lying
loose. Then they have to drop that over, after testing it to
see how long it is, and go on toward the shore and begin over
again. In this case, however, they found that they had hold
of a sound wire to Great Britain. Without any delay, the
end of a new cable was spliced to the old end brought from
the bottom. Two experts, one who is trained in splicing
cores, and one who is trained in splicing the outside or
sheathing, are employed in this work.
When the splice was completed and tested, and found
perfect, the cable was started, running out around drums
and grooved wheels controlled by brakes, and over the stern,
the old end having been led fair through these sheaves before
the splicing was done. Then the ship headed for shoal water,
and ran away at from three to four knots an hour until over
a part of the banks where work could be done more easily
than where the water was more than two miles deep. Of
course this involved the abandonment of a good many miles
of old cable, but the old cable wasn't of very much impor-
tance anyhow.
Arriving in shoal water, the end of the new piece was
attached to a buoy and put overboard. Then the old cable
was grappled and cut as before, and a new piece spliced to
it. Then the ends of the two new pieces were spliced to-
gether and the job was complete. It had taken nearly two
months to do it, although in the meantime two easier jobs
were attended to, and a trip to Halifax for provisions was
made, not to mention the encountering of the storm that
damaged the rudder.
The " Minia " has a crew of ninety, all told, including the
captain, three deck officers, a navigator, three expert elec-
tricians, four engineers, a purser and a surgeon. A black-
smith and a boiler maker, with their tools, are carried. There
are three big, round tanks to ho'd the 600 miles of cable
cariied, which includes sizes to fit ail the old cables under the
charge of this shijj. There is a cell-room where the electricity
for telegraphing is generated, and two dynamos with their
engines, one to furnish electricity for a system of arc lights
used wh^n at work at night, and the other for the incandes-
282
cent system that lights the ship below decks. The main
saloon is large, and is comfortably and handsomely fitted.
The captain has a cabin under the turtle-back aft, as fine as
any captain could wish for, and the other officers have rooms
below that are as well fitted as those usually occupied by
naval officers. The crew are all expert men, and get pay
that averages a good deal better than ihe pay in the packet
service between New York and Liverpool. The entire crew
is kept under pay the year round, the ship making her head-
quarters at Halifax when not engaged in repairing cables.
They are as comfortable a lot of sailor men as one could find
anywhere.
Till'! LONGEST KLECTRIC RAILROAD IX THE
COUNTRY.
The longest electric railroad in this country is one under
contract at Topeka, Kansas. The length of the road is to be
fourteen miles and \vill require fifty cars. The Thomson-
Houston system has been applied.
The breaking strain on various metals is shown in the
following table, the si/e of the rod tested being. in each case
one inch square, and the number of pounds the actual break-
ing strain :
Pounds.
Hard steel 150.000
Soft steel 120,000
Best Swedish iron . 84,000
Ordinary bar iron 70,000
Silver 41,000
Copper 35>ooo
Gold 22,000
Tin 5,500
Zinc '. 2,600
Lead 860
To make varnish adhere to metal, add five-hundredthsper
cent, of boracic acid to the varnish.
Machinery will do almost anything, and what machinery
can't do a woman can with a hairpin.
To find the weight of a cast-iron ball, Ilaswellsays — Mul-
tiply the cube of the diameter in inches by 1365, and the
product is the weight in pounds.
NUMBER OF REVOLUTIONS OF WATCH
WHEELS.
Very few who carry a watch ever think of the unceasing
labor it performs under what would be considered shabby
treatment for any other machinery. There are many who
think a watch ought to run for years without cleaning, or a
drop of oil. Read this and judge for yourself: The main
wheel in an ordinary American watch makes 4 revolutions
a day of 24 hours, or 1,460 in a year. Next, the center
wheel, 24 revolutions in a day, or 8,760 in a year. The
third wheel 192 in a clay, or 59,080 in a year. The fourth
wheel, 2,440 in a day, or 545,600 in a year. The fifth, or
'scape wheel, 12,960 in a day, or 4, 728,200 in a year. The
ticks or beats are 388,800 in a day, or 141,882,000 in a year.
A VALUABLE POINT FOR HOLDERS.
It is claimed that a saving, as well as a better job, can be
effected by the substitution of the following for the coal dust
and charcoal used with green sand : Take one part common
tar, and mix with 20 parts of green sand; use the same as
ordinary facing. The castings are smooth and bright, as tar
prevents metal from adhering to the sand, prevents formation
of blisters, and helps the production of large castings by
absorbing the humidity of the sand.
METRICAL AND CENTIGRADE EQUIVALENTS.
As much of the scientific literature of the steam engine,
the metrical system of weights and measures and the centi-
grade thermometrical scale are used, we publish the following
equivalents, which may be of use to our readers in readily
reducing them to British units :
kilogrammetre. 7>233 f°ot pounds.
foot pound 188 kilogrammetre.
French horse power (chevelvapeur) 75 kilo-
grammetres per second 9863 horse power.
British horse power 1.0139 chevaux.
kilogramme per cheval 2,239 pounds H. P.
pound per horse power 447 kilo, per chevaJL
caloric, or French heat unit 3.968 British unltS
British thermal unit 252 caloric.
French mechanical equivalent, 423.55 (usually
called 424) kilogrammetres 3063. 5 ft. pounds.
English mechanical equivalent, 772 footpounds 10.76 kilogrammetre
284
A NEW ALLOY.
An alloy, the electrical resistance of which diminishes
with increase of temperature, has recently been discovered.
It is composed of copper, manganese and nickel. Another
alloy, due to the same investigator, the resistance of which is
practically independent .of the temperature, consists of 70
parts of copper combined with 30 of ferro-manganese
USE OF NATURAL GAS IN CUPOLAS.
At Pittsburgh, Pa., natural gas has been utilized in
cupolas for ordinary castings. The apparatus consists of a
series of pipes, covered with fire-clay tiles, and, at the same
time, ventilating the pipes with a current of air. A combus-
tion chamber is necessarily connected with the furnace, to
insure the required heat and prevent the chilling of the fur-
nace.
A NEW CEMENT.
A cement called magnesium oxychloride, or white cement,
has been discovered, and is now manufactured in California,
as we learn from an exchange. It is composed of one-half
(l/2) magnesium oxide, which is obtained from the magnesite
deposits in the Coast Range, and one-half (^) magnesium
chloride, obtained from various sea-salt manufactories
throughout the State. It may be used for sidewalks, and for
interior decorating, and in appearance resembles pure white
marble. It has a natural polish, and, above all, is much
cheaper than any of the other substances now in use.
HOW TO CAST A FACE.
The person whose face is to be " taken " is placed flat
upon his back, his hair smoothed back by pomatum to pre-
vent it covering any part of the face, and a conical piece of
paper or a straw, or a quill put in each nostril to breathe
through. The eyes and mouth are then closed and the entire
face completely and carefully covered with salad oil. The
plaster, mixed to the proper consistency, is then poured in
large spoonfuls to the thickness of one-quarter or one-half
inch, in a few minutes this can be taken off as if it were a
film. When a cast of the entire head or of the whole human
figure is required, either a cast of the face is added to a mass
of clay, which is to be modeled to the required figure, or the
whole figure is modeled from drawings prepared for thai-
purpose T! > is the work of the sculptor.
When the clay model is finished, a mold is made from it
as in the former cases. If the model be a bust, a thin ridge
of clay is laid along the figure from the head to the base, and
the front is first completed up to the ridge by filling up the
depressions two or three inches deep. The ridge of clay is
now removed, the edges of the plaster are o'led, and the
other half is clone in a similar way. The two halves are like-
wise tied together with cords, and the plaster is poured in.
In complicated figures, say a " Laocoon," the statue is oiled
and covered with gelatine, which is cut off in sections by
means of a thin, sharp knife, each piece serving as a Mold
for its own part of the new statue.
MELTING POINTS OF METALS.
Metals.
Centigrade.
Fahrenheit.
Aluminum
deg
rees 700
425
'£
264
320
,200
,091
,38l
I76
»530
,200
,400
334
235
— 40
i, 600
62
2,600
1,040
96
235
412
deg
<
i
rees 1,292
797
365
507-2
608
' 2,192
1,995.8
< . 2,485. r*
348.8
2,786
* 2,192
2,552
617
455
-40
2,912
143.6
4,712
1,904
172.8
455
773-6
Antimony
Arsenic
Bismuth
Cadmium
Cobalt
Copper
Gold
Indium
Iron, wrought
Iron, cast
Iron, steel
Lead
Magnesium
Mercury
Nickel
Potassium
Platinum
Silver
Sodium
Tin . . .
Zinc
According to experiments recently made at the Royal
Polytechnic School at Munich, the strength of camel hair
belting reaches 6,215 pounds per square inch, while that of
ordinary belting ranges between 2,230 pounds and 5,260
pounds per square inch.
286
WEIGHT AND SPECIFIC GRAVITY OF METAL.
Metals.
Wt. pr
cubic ft.
Wt. pr
cubic ft.
Specific
grav.
Aluminum. ...
Lbs.
1 66
419
613
524
534
537
555
1208
1106
528
450
485
708
711
849
1344
H36
654
644
490
455
437
Lbs.
.096
.242
•353
•3
.308
•3i
•32
.697
.638
•304
.26
.28
.408
.j.i
.489
•775
.828
•377
•371
.284
.262
.252
2.67
6.72
9.822
8.4
8.561
8.607
8.9
19.361
17.724
3-459
7.21
7.78
11.36
11.41
I3-596
21-531
23-
10.474
10.312
7-85
7.29
7-
Antimony, cast
Bismuth
Brass, cast
Bronze
Copper, cast
( ' wire
Gold, 24 carat
* ( standard
Gun-metal
Iron, cast .
" wrought
Lead, cast
" rolled
Mercury .
Platinum
sheet
Silver, pure
'* standard
Steel.
Tin, cast
Zinc
HOW TO MEND PATTERNS.
For mending patterns needing temporary repairs,or for
making additions where but one or two molds are to be
made, the following material will be found very useful.
Melt together I pound beeswax, i pound rosin and one
pound paraffine wax. It is well to note here that the bees-
wax intended is the wax made by the bees, and not the
wax made by the wholesale dealers. The cheap wax sold
to the shipping houses contains but a small portion of
the article made by the bees, and a large proportion of
soft paraffine wax. The result of using this compound wax
instead of the genuine article, in any mixture, is to intro-
duce too much paraffine and only a little beeswax. When
the genuine article is used, this mixture will be found
very useful for making addition to patterns, temporary
patterns, and for a variety of purposes in pattern shop.
287
VALUE OF METALS.
Gold by the pound avoirdupois.
Vanadium (cryst. fused) $4,792.40
Rubidium (wire) , 3,261 .60
Calcium (electrolyctic) 2,446.20
Tantalum (pure) 2,446.20
Cerium (fused globules) 2,446.20
Eithium (globules) 2,228. 79
Lithium (wire) 2,935.44
Lubium (fused) ,67 1 .57
Didymium (fused) ,620.08
Strontium (electrolyctic) ,576.44
Indium (pure) ,522.08
Ruthenium ,304.64
Columbium (fused) ,250.28
Rhodium ,032. 84
parium (electrolyctic) 924. 12
ralliu'H 73&39
Osmium 652. 32
Palladium 498.30
Indium. 466. 59
Uranium 434.88
Gold 299.72
Titanium (fused) 239.80
Tellurium " 196.20
Chromium " 196.20
Platinum " 122.31
Manganese " 108. 72
Molydenum. 54-34
Magnesium (wire and tube) 45-3°
Potassium (globules) 22.65
Silver 18.60
Aluminum (bar) 16.30
Cobalt (cubes) 12.68
Nickel 3.80
Cadmium 5.26
Sodium 3.26
Bismuth (crude) 1-95
Mercury. J .00
Antimony .36
Tin.....' .25
Copper .22
Arsenic .15
Zinc .10
Lead .06
Iron.. .1%
288
LENGTH PER COIL AND WEIGHT OF ROPE PER
HUNDRED FATHOMS.
Manila and Sisal Rope.
Tarred
Cordage.
Diameter in
inches.
Cir. in
inches
Le'gth
in feet.
Lbs.
per
lOoFa
Le'gth
in feet.
Lbs.
per
loo Fa
# or 6th.
#
1,300
'12
840
18
5-16 or Qth.
15-16
1,300
17
840
29
ft or I2th.
iH
1,200
23
840
40
15 thread.
15 thread.
1,200
31
840
47
I 8 thread.
1 8 thread.
1,100
45
840
58
21 thread.
21 thread.
I,IOO
5°
840
68
#
i#
990
' 52
960
64
9-16
#
i#
2
990
99°
7°
83
960
960
79
94
*,
2X
990
105
960
130
%
2^
99°
125
960
140
15-16
2^?
990
155
960
170
3 ,
99°
175
960
207
1-16
3#
99°
205
960
238
3-16
3X
990
255
960
272
X
3^
990
280
960
300
S-i6
4
960
310
960
332
n
4*
960
355
960
376
yt
4^
960
410
96o
440
H
4^
96o
450
960
505
11-16
5
960
500
960
573
iH
sX
960
550
960
610
1%
5K
960
610
960
654
I 15-16
5¥
960
690
960
797
2
6
960
750
960
900
2 3~l6
6^
960
845
960
1.057
2*/S
7
960
1,000
960
1,163
2%
rA
960
1,100
960
i>35^
2#
8
960
1,270
960
1,613
3
9
960
i»595
960
2,013
HOW TO MAKE BRONZE MALLEABLE.
Domier has discovered that bronze is rendered malleable
by adding to it from one-half to two per cent, of mercury.
289
WHEN A DAY'S WORK BEGINS.
The decision of the Supreme Court that a workman who
has agreed to do work at a specified sum per hour, is not
entitled to charge for the time spent in going to or returning
from work, is one that equitably applies to some kind^of
business, but not to others. Where house-building mechan-
ics have several days' work to do at a building, and their
tools and materials are on the spot, they are expected t > re-
port at the building in time to do a full day's work. Where
they are doing odd jobs and are obliged to siart from the
shop in the morning, they do so at the regular hour for
beginning work, thus reducing the hours of actual labor.
But they must be paid for the whole day, and the person for
whom the work is done must be charged for the time occu-
pied in going to and from the job; otherwise, the " boss"
would have to pay his journeymen, for say tea hours* \\ork.
though accounting for only s.x hours work' in his bill to cus-
tomers. In some. of the small trades a journeyman will go to
half a doze.i houses in a day, doing an hour's work in, each,
and spending the other four hours in passing from one job to
another. In one way cr another he is bound to be paid for
the whole time. If he can charge only for the actual work-
ing time, then his rates will be increased so as to compensate
him for the time spent in service that is not to be paid for.
The decision shows the importance of making agreements of
this kind specific, both as to the rate of wages and the hours
and kind of service.
CAMEL'S-HAIR BELTING.
Camel's-hair belting has been recently the subject of
experiments at the Polytechnic school, at Munich, from
which it Dopears that the strength of camel's-hair belting
reaches 6,315 pounds per square inch, whilst that of ordinary
belting ranges between 2,230 pounds and 5,260 pounds per
square inch. A contemporary says the camel's-hair belt is
said to work smoothly and well, and it is unaffecte^ ty
acids
TO PERFORATE GLASS.
In drilling glass, stick a piece of stiff clay or putty on tht
part where you wish to make the hole. Make a hole in tte
putty the size you want the hole, reaching to the glass, of
course. Into this hole pour a little molten lead, when,
unless it is very thick glass, the piece will immediately drop
290
HIGH SPEED GEARING.
During the last few years, and particularly since the
adoption of double-heliacal teeth, a great increase has been
made in speed at which gearing is run, and, in many cases,
there are now successfully adopted speeds which in former
days would have been regarded as utterly impracticable.
The most striking instances of this which we have come
across, is in the case of a pair of double-heliacal wheels at
the works of Messrs. R. Johnson & Nephew, the well known
wire-drawers of Manchester. These wheels, which were cast
by Messrs. Sharpies & Co., of Ramsbottom, Lancashire, are
12 in. wide on the face, by 6 ft. 3 in. diameter, and they have
now been running for over a year at 220 revolutions per
minute, the pitch-line speed being thus 4,319 ft. per minuls.
Notwithstanding this enormous speed, the wheels run with
Scarcely any noise, and their working has been most satis-
factory. This is the highest speed we have heard of for
geared wheels, running iron to iron, and the fact that it ha»
been adopted with success, is a most interesting one.
The large gear on the Corliss engine at the Centennial
Exhibition was 30 feet in diameter, outside, and ran at 36
revolutions per minute. It had a 24-in. face, and the speed
of the pitch-line is about 3, 360 ft. per minute. This speed is
exceeded by a similar gear, also made by Mr. Corliss, which
is now running in a mill in Massachusetts. It is 30 ft. in
outside diameter, and has a 3o-in. face. It makes 50 revolu-
tions per minute, and the speed of the pitch-line is not far
from .4,670 ft. per minute. This is probably the highest
speed at which any gear has yet been run continuously.
The Corliss gears are all accurately shaped by a revolving
cutter: but it is probable that Messrs. Sharpies & Co.'s gears
are not cut, but cast, and then finished up by hand. If that
is the case, their performance is much more remarkable than
that of the Corliss gears.
THE WORLD'S STEAM ENGINES.
According to the Berlin Bureau of Statistics, there is in
the world the equivalent of 46,000,000 horse-power in steam
engines, 3,000,000 being in locomotives. In engines other
than locomotives, the United States comes first with 7,500,-
<X>o horse power; England next with 7,000,000 horse power;
Germany 4,500,000 horse-power; France 3,000,000 horse-
pdwer, and Austria 1,500^000. Four-fifths of the si en in
engines now in operation are said to have bee i built within
the last twenty-five years
291
LIABLE TO SPONTANEOUS COMBUSTION.
Cotton-seed oil will take fire even when mixed with
twenty-five pe/ cent, of petroleum oil ; but ten per cent, of
mineral oil mixed with animal or vegetable oil, will go far to
prevent combustion.
Olive oij is combustible, and, mixed with rags, hay or
sawdust, will produce spontaneous combustion.
Coal dust, flour-dust, starch (especially rye flour), are all
explosive when with certain proportions of air.
New starch is highly explosive in its comminuted state,
also sawdust in a very fine state, when confined in a close
»lhute, and water directed on it. Sawdust should never be
used :xi oil shops or warehouses to collect drippings or leak-
ages from casks.
Dry vegetable or animal oil inevitably takes fire, when
saturating cotton waste, at 1 80° F. Spontaneous combustion
occurs most quickly when the cotton is soaked with its own
weight of oil. The addition of forty per cent, of mineral oil
(density .890) of great viscosity, and emitting no inflammable
vapors, even in contact with an ignited body at any point
below 338° F. , is sufficient to prevent spontaneous combustion,
and the addition of twenty per cent, of the same mineral oil
doubles time necessary to produce spontaneous combustion.
Greasy rags from butter, and greasy ham bags.
Bituminous coal in large heaps, refuse heaps of pit coal,
hastened by wet, and especially when pyrites are present in
the coal ; the larger the heaps the more liable.
Timber dried by steam pipes or hot water, or hot air
heating apparatus, owing to fine iron dust being thrown off,
in close wood-casings, or boxings round the pipes, from the
mere expansion and contraction of the pipes.
Patent dryers from leakages into sawdust, etc., oily waste
of any kind, or waste cloths of silk or cotton, saturated with,
oil, varnish, turpentine.
HOW COMBUSTION IN COAL IS PPODUCED.
In a ton of anthracite coal, there is about 1,830 Ibs. of car-,
bon, 70 Ibs. of hydrogen and 52 Ibs. of oxygen; while a ton
of good bituminous coal is composed of 1, 600 Ibs. of carbon,,
108 Ibs. of hydrogen and 32 Ibs. of oxygen. The combus-
tion of coal proceeds from its combination with oxygen gas,,
and, when fuel of any kind combines with oxygen, heat is pro* '.
duced. All bodies, substances, gases and liquids, are com-
posed of separate particles, often of molecules of inconceiv-
able smp!1n;s>. These particles, it is scientifically conceded,
292
are in motion among themselves, and this motion constitutes
feat, for heat is only a kind of motion. This internal vibra-
tion of mfinitesirnal particles may be transmuted into a per-
ceptible mechanical movement, or the mechanical movement
may be converted into the invisible motion called heat. The
oxygen combined with coal has a very considerable range of
internal motion, and the combining process produces carbonic
acid gas; and, the particles of this gas having a much smaller
range of motion than the particles of the oxygen have, the
difference appears in the form of heat.
CAPACITY OF CYLINDRICAL CISTERNS.
The following table shows the capacity in gallons for
each foot in depth of cylindrical cisterns of any diameter:
Diameter. Gallons. Diameter. Gallons.
25 ft- 3.059 7 ft- 239
20 ft. *>958 6^ ft. 206
15 ft. 1,101 6 ft. 176
14 ft. 959 5 ft. 122
13 ft- ^27 4# ft. 99
12 ft. 705 4 ft. 78
ii ft. 592 3 ft. 44
10 ft. 489 2% ft. 30
9 ft. 396 2 ft. 19
8 ft. 313
HOW TO SELECT A HAND SAW.
A saw-maker has this advice to give to carpenters in the
selection of a saw:
"See that it 'hangs' right. Grasp it by the handle and hold
it in position for working to see if the handle fits the hand
properly. A handle should be symmetrical, and the lines
perfect. Many handles are made of the green wood; they
soon shrink and become loose, the screws standing above
the wood. An unseasoned handle is liable to warp and throw
the saw out of shape. Try the blade by springing it. seeing
that- it bends evenly from point to butt i i proportion as the
•wLltli and gauge of the saw vary. The bl ide should not be
too heavy in comparison to the teeth, as it will re-quire more
labor to use it. The thinner you can get a stiff saw she bet-
ter: it makes less 'kerf and takes less muscle to drive it.
"•See that the saw is well set and has a good crowning
breast. Pluce ir, at a distance from you; .net a pr«p«r light
on it. and you can see if there has been any imperfections in
grinding or hammering."
FBOM ONE TON OF COAL.
From one ton of ordinary gas coal may be produced 1,500
pounds of coke 20 gallons of ammonia water and 140 pounds
of coal tar. By destructive distillation the coal tar will
yield 69.5 pounds of pitch. 17 pounds of creosote. 14 pounds
of heavy oils. 9,5 pounds of naphtha yellow, 6.3 pounds <>f
naphfha'in^. 4. 75 p Minds of iriphtix*!. 2 25 pounds of solvent
na'.Ki'h.i. 1 5 pounds of i>hen<>!. 1.2 pounds of aurine, 1.1
pounds of benzine, 1 1 pounds «>f analine, 0.77 of a pound of
loludine, 0.46 of a pound of anthracine and 0.9 of a pound of
toulene. Prom the latter is obtained the new substance
known as saccharine, which is 530 times as sweet as the best
cane sugar, one part of it giving a vei y sweet taste to a thou-
sand parts of water.
HOW TO SELECT ROPE.
A German paper, in an article on the present methods of
rope manufacture from hemp, and the determination of the
different qualities and the probable strength simply from the
appearance, lays down the following rules: A good hemp
rope i .; hard hut pliant, yellowish and greenish gray in color,
with a certain .silvery or pearly Lister. A dark or blackish
color indicates that the hemp has suffered from fermentation
in the process of curing, and brown spots show that the rope
was spun while the fibers were damp, and is consequently-
weak and soft in those places. Again, sometimes a rope is
made with inferior hemp on the inside, covered with yarns
of good material — a fraud, however, which may be detected
by dissecting a portion of the rope, or, in practical hands, by
its behavior in use ; other inferior ropes are made with short
fibers, or with strands of unequal strength or unevenly spun
— the rope in the first case appearing wooly, on account ol
the number of ends of fiber projecting, and, in the latter
case, the irregularity of manufacture is evident on inspection
by any good judge.
THINGS THAT WILL NEVER BE SETTLED.
Whether a long screw-driver is better than a short one
of the same family.
Whether water-wheels run faster at night than they do in
the day time.
The best way to harden steel.
Which side of the belt should run next to the pulley.
The proper speed of line shafts.
The right way to lace belts.
Whether compression is economical or the reverse.
The principle of the steam injector.
294
THINGS WORTH KNOWING.
Dominer has discovered that bronze is rendered malleable
by adding to it from one-half to two per cent, of mercury.
An " inch of rain " means a gallon of water spread over a
surface of nearly two square feet, or a fall of about loo tons
on an acre of ground..
A steam power plant is divided into five fundamental
parts by a French author — the boiler, motor, condenser,
distributing mechanism, and mechanism of transmission.
Turpentine and black varnish, put with any good stove
polish, is the blackening used by hardware dealers for polish-
ing heating stoves. If properly put on, it will last throughout
the season.
A workman in the Carson mint has discovered that drill
points, heated to a cherry-red and tempered by being driven *
into a bar of lead, will bore through the hardest steel or plate
glass without perceptibly blunting.
To harden copper, melt together, and stir till thoroughly
incorporated, copper and from one to six per cent, of mand-
ganese oxide. The other ingredients for bronze and other
alloys may then be added. The copper becomes homogene-
ous, harder and tougher.
SIMPLE TESTS FOR WATER.
Boiler-users who desire simple tests for the water they
are using will find the following compilation of tests both
useful and valuable :
Test for Hard or Soft Water— Dissolve a small piece
of good soap in alcohol. Let a few drops of the solution
fall into a glass of the water. If it turns milky, it is hard
water; if it remains clear, it is soft water.
Test for Earthy Matters or Alkali — Take litmus-paper
dipped in vinegar, and, if on immersion the paper returns
to its true shade, the water does not contain earthy matter
or alkali. If a few drops of syrup be added to a water con-
taining an earthy matter, it will turn green.
Test for Carbonic Acid — Take equal parts of water
and clear lime water. If combined or free carbonic acid is
present, a precipitate is seen, to which, if a few drops of
muriatic acid be added, effervescence commences.
Test for Magnesia — Boil the water to twentieth part of
its weight, and then drop a few grains of neutral carbonate
of ammonia into a glass of it and a few drops of phosphate
oCsoda. If magnesia is present, it will fall to the bottom.
Tist for Iron — Boil a little nut-gall and add to the
water. If it turns gray or slate-black, iron is present.
Second: Dissolve a little prussiate of potash, and, if iron U
present, it will turn blue.
Test for Lime — Into a glass of water put two drops of
oxalic acid, and blow upon it. If it gets milky, lime is present
Test for Acid — Take a piece of litmus-paper. If it
turns red, there must be acid. If it precipitates on adding
lime water, it is carbonic acid. If a blue sugar paper is
turned red, it is a mineral acid.
Test for Copper — If present, it will turn bright
polished steel a copper color. Second : A few drops of
ammonia will turn it blue, if copper is present.
Tests for Lead — Take sulphureted gas and water in
equal quantity to be tested. If it contains lead, it will turn
a blackish brown. Again : The same result will take place
\f sulphate of ammonia be used.
T*est for Sulphur — In a bottle of water add a little
q '^silver, cork it for six hours, and, if it looks dark on
tli pp, and on shaking looks blackish, it proves the presence
of sulphur.
JAPANESE LACQUER FOR IRON SHIPS.
The Japanese Admiralty has finally decided upon coating
the bottoms of all their ships with a material closely akin to
the lacquer to which we are so much accustomed as a
specialty of Japanese furniture work. Although the prep-
aration differs somewhat from that commonly known as
Japanese lacquer, the b^se of it is the same — viz., gum-lac,
as it is commonly termed. Experiments, which have been
long continued by the Imperial Naval Department, have
resulted in affording proof that the new coating material
remains fully efficient for three years, and the report on the
subject demonstrates that, although the first cost of the
material is three times the amount of that hitherto employed,
the number of dockings required will be reduced by its use to
the proportion of one to six. \ vessel of the Russian Pacific
fleet has already been coated with the new preparation,
which, the authorities say, completely withstands the fouling
influences so common in tropical waters. It took the native
inventor many years to overcome the tendency of the lac to
harden and crack; but having successfully accomplished this,
the finely-polished surface of the mixture resists in an almost
perfect degree the liability of barnacles to adhere or weeds *o
296
grow, while, presumably, the same high polish must materi-
ally reduce the skiu friction which is so important an elejnent
affecting the speed of iron ships. The dealers in gum-lac
express the fear lest the demand likely to follow on this novel
application of it may rapidly exhaust existing sources of
supply.
IRON IN THE CONGO.
Last year Mr. Dupont, director of the Museum of Natural
History of Brussels, went to the Congo for the purpose of
studying the geology of the valley from the Atlantic to the
confluence of the Kassai River, over 400 miles from the coast.
After eight months devoted to this work, he has returned to
Europe, bringing some surprising reports with regard to the
mineral resources of the region. He says that throughout
the entire extent of the country he found in the plateaus
skirting the river, under the thick alluvium, a stratum of iron
ore from a foot and a half to three feet in thickness. In
numerous places he saw blocks of iron ore sometimes many
cubic feet in dimensions, upon the slopes of ravines, where
they had been exposed by denudation. He asserts that there
is scarce' y a country in the world so rich in iron ore as the
Cor^o basin, and the mineral is not only abundant, but can
also be easily reduced. In his opinion, if the other continents
ever exhaust their resources of iron, the Congo basin can sup-
ply the rest of the world for a long period.
GLASS CUTTING BY ELECTRICITY.
The cutting of glass tubes of wide diameter is another of
the almost innumerable industrial applications of electricity.
The tube is surrounded with fine wire, and the extremities of
the latter are put in communication with a source of electricity,
and it is of course necessary that the wire adhere closely to
the glass. When a current is passed through the wire, the
latter becomes red hot and heats the glass beneath it, and a
single drop of water deposited on the heated place, will cause
a clean breakage of the g'ass at that point. Contrary to
what takes place with the usual processes in the treatment of
this frangible material, jt is found that, the thicker the sides
of the tubes are, the better the experiment succeeds.
They have been making 38-ton guns at Portsmouth,
England, and are talking of introducing the 47-ton variety.
Nearly 35,000 people live at Portsmouth on wages earned in
doing some kind of work on Kn^ml'' big guns.
297
OTA* NESS CAUSED BY THE ELECTRIC
LIGHT.
A curious phenomenon was recently related by M. D'Ar-
sonval before the French Academy of Medicine. After gazing
for a few seconds on an arc light of intense brilliancy, he
suddenly became deaf, and remained so for nearly an hour
and a half. Surprised, and somewhat alarmed in the first
instance, but reassured by the d.sa]»r-e.i ranee of the symp-
toms,, he repeated the experiment with the same result.
When only one eye was exposed to the light, no very marked
effect was produced.
BROWNING GUN BARRELS.
Mix 16 parts sweet spirits niter, 12 parts saturated solu-
tion of sulphate of iron, 12 parts chloride of antimony. Bot-
tle and cork the mixture for a day, then add 500 parts of
water and thoroughly mix. Clean the barrel to a uniform
grain free from grease and finger stains. Wipe with a stain-
ing mixture on a wad of cotton. Let it stand for twenty-four
hours, scratch brush the iarface and repeat twice. Rub off
the last time with leathei -aioistened with olive oil. Let dry
a day, and rub down \\ith a cloth moistened with oil to
polish.
SPONTANEOUS COMBUSTION
There is a remarkable tendency observable in tissues and
cotton, when moistened with oil, to become heated when
oxidation sets in, and sad results often follow when this is neg-
lected. A wad of cotton used for rubbing a painting has
been known to take fire when thrown through the air. The
waste from vulcanized rubber, when thrown in a damp con-
dition into a pile, takes fire spontaneously. Masses of
coal stored in a yard have been known to take fire without a
spark being applied, and one cannot be too careful in
storing any substance in which oxidation is liable to take
place.
A LARGE LUMP OF COAL.
One of the largest lumps of coal ever mined in the Monon-
gahela Valley was taken from J. S. N eels' Cincinnati mines,
near Monongahela City, lately. The block measured 7 feet
8 inches long, 3 feet 5 inches high, and 3 feet 7 inches wide.
A temporary track was laid to the river, and the big piece o^
coal loaded in a boat, for Cincinua.' i.
SCREW-MAKING AT PROVIDENCE, RHODE
ISLAND.
It is not known when screws were first made and brought
into use. The first instance known of machinery being applied
to the making of screws, was in France, in 1569, by a man
named Besson, who contrived a screw-cutting gauge to be
used in a lathe. The early method had been to make the heads
by pinching the blanks while red hot between dies, and then
to form the threads by the process of filing. In 1741 Besson's
device was improved by Hindley, a watchmaker, of York,
England; and for a long time the watch-makers of that
country used this device in making the small screws used in
their work. The first English patent appears to have been
issued to Job and William Wyatt, in 1760, for three machines
— one for making blanks, another for nicking the heads, and
a third for cutting the threads. Between that date and 1840
about ten patents were issued, only one of which is worthy of
notice, namely that of Miles Berry, d?*ed January 28, 1837,
which was for a gimlet-pointed screw. The first American
patent was issued December 14, 1798, to David Wilkinson, a
celebrated mechanic of Rhode Island. ' The next American
patent was dated March 23, 1813, and was issued to Jacob
Perkins, of Newburyport, Mass. In that year, also, a patent
was granted to Jacob Sloat, of Ramapo, N. Y. At the exten-
sive nail and iron works of the Piersons, established in Ram-
apo in 1798, Thomas W. Harvey in 1831 applied the tog-
gle-joint to the headings of screws, rivets and spikes. In 1834
Mr. Harvey entered into partnership with Frederick Goodell,
a cotton manufacturer of Ramapo, and established a small
screw manufactory at Poughkeepsie, and early in the next
year Mr. Harvey invented machines for heading, nicking and
shaving screws. These and a thread-cutting machine, pur-
chased from its inventors, Jacob Sloat and Thomas Spring-
steen, were successfully operated, producing a gimlet-pointea
screw.
It is interesting to note that, while the manufacture of
wood screws probably originated in Westphalia, Germany,
and was subsequently carried on in eastern France and Eng-
land before its introduction into this country, American in-
ventors have supplied the machinery that is now universally
employed. The popular feeling that the gimlet -pointed screw
was a modern invention is erroneous. The company has in
its possession sample cards of French screws, pointed, though
299
not as perfectly made as at present, which were brought from
France early in the present century, and from an old piano
now at Northampton, made about the year 1750, screws have
been taken showing the same feature. Patents have been
issued on gimlet-pointed screws, but they covered only a
peculiar form of point.
The Eagle Mill of the American Screw Company is
devoted to the manufacture of wood screws. In the yard
connected with this mill are landed the rods, in coils, from
which the screws are to be manufactured. The larger por-
tion of these rods is .issrswDed from Sweden, Germany and
England. The £r?>t; room into which the reader is to be con-
ducted is the "pickling room." Here the rod is "pickled"
for the purpose of removing the flinty scale on the outside;
and the action of the mixture in that process tends to facil-
itate the drawing of the wire. After being annealed in fur-
naces the wire is subjected to the pointing process, the pur-
pose of which is to reduce the end of the rod to enter the
draw-plate. The wire is taken into the drawing room, where
it is drawn in different sizes needed for the great variety of
screws. The machinery for the different processes is the
result of the skill of many inventors, who have produced a
system of machines mostly automatic and beautiful in opera-
tion. By the automatic wire block used, if anything happens
to the wire while going through the process, the whole appa-
ratus stops. If it did not stop, the wire would break. By a
machine, whose action is accurate and fascinating, the rod
is cut into the sizes of the screws desired and the head
put on almost at the same instant. The metal, in going
through this process, necessarily becomes very oily.
These "blanks," for such they are called at this stage
of their manufacture, are put into what are called "rat-
tlers," revolving boxes, hexagonal in shape, tilled with saw-
dust, where they are cleansed of the oil that covers them, the
oil eeing absorbsed by the sawdust. The blanks are ready to
feave their heads "shaved," which consists in cutting the
heads perfectly round. The blanks are put into a hopper, and
by an automatic feeder they are let down into a trough, from
which they are picked by a metal finger and put into a spin-
dle. The heads are then "shaved," and by a revolving spin-
dle the blank is taken to the small saw which cuts the slot in
the head. Tbe blank is then revolved back again and shaved
again, to get rid of the "burr," or the rough edge left by the
tool, in cutting the slot. The blanks are then fired out of
Vhe machine absolutely perfect. The machine is an automatic
300
but very complicated one ; every part of it, however, does its
work effectively. The blanks, after being shaved and slotted,
are placed in another machine and threaded, when the screw
is complete.
HOW THERMOMETERS ARE MADE.
The first point, in the construction of the mercurial ther-
mometer, is to see that the tube is of uniform caliber through-
out its whole interior. To ascertain this, a short column of
mercury is put into the tube and moved up and tlowr, to see
if i'.s length remai' s the same through ail parts of tl.e tube.
If a tube whose caliber is not uniform is used, slight differ-
ences are made in its graduation to allow for this. A scale
of e jual parts is etched upon the tube; and from observations
of the inequalities of the column of mercury moved in it, a
table gj.ving the temperatures corresponding to these divisions
is formed. A bulb is now blown on the tube, and vhileihe
open end of the latter is dipped into mercury, heat is applied
to the bulb to expand the air in it. This heat is then with-
drawn, and theair within contracting, a portion of the merci ry
rises in the tube, and partly fills the bulb. To the open end of
the bulb a funnel containing mercury is fitted, and the bulb
is placed over a flame until it boils, thus expelling all air and
moisture from the instrument. On cooling, the tube
instantly fills with mercury. The bulb is now placed in
some hot fluid, causing the mercury within it to expand and
flow over the top of the tube, and, when this overflow has
ceased, the open end of the tube is heated with a blow-pipe
flame. To graduate the instrument, the bulb is placed in
melting ice; and, when the top of the mercury column has
fallen as low rs it will, note is taken of its position as com-
pared with the scale on the tube. This is the freezing point.
Jt is marked as zero on the thermometers of Celsius and
Reaumur, and as 32° on the Fahrenheit class.
To determine the boiling point, the instrument is placed
in a metallic vessel with double walls, between which circulates
the steam from boiling water. Between the freezing and
boiling point of water, 100 equal degrees are marked in the
centigrade graduation of Celsius, 180° on the Fahrenheit
plan, and 80° on the Reaumur. In many thermometers, all
three of these graduations are indicated on the frame to which
the tube is attached. Some weeks after a thermometer has
been made and regulated, it may be noticed that, when the
bulb is immersed in pounded ice, the mercury does not quite
descend to the freezing point This is owing to a gradual
expansion of the mercury, which usually goes on for nearly
3oi
two years, when it is found that the zero point has risen
nearly a whole degree. It is then necessary to slide dowa
the scale to which the tube is fastened, so that it will accurately
read the movements of the mercury. After this change, the
accuracy of the thermometer is assured, as there is no iurther
txpansion of the mercury column.
POINTS FOR APPRENTICES.
In starting to learn a trade as an apprentice, first imagine
yourself brighter, and more apt to learn, than the older
apprentices in the shop. Criticise their work on the last range*
they blacked. Show the red spots under the doors or under
the top plates, and if you are not dropped through the trap
door into the cellar the first opportunity they get, it will be
some good fortune that favors you. When working with a
jour., tell him how Tom Jones does that, and his ways are
not right, or tell him how to do it. Of course the jour, ha?
worked fifteen years at the business, but that doesn't make
any difference, you go ahead. If he does not call you c us*
words and tell you to mind your business, he must have
a mother-in-law who comes over to see him seven times a day*
and stays all clay Sunday.
When you have worked about a year at the business and
you think you are competent to take charge of the shop, and
you are given a job of cleaning a furnace, which, of course,
will smut a boiled shirt, you go home, and kick to the old
folks; say you are not going to work for Smith any more, at
he gives you all the dirty work to do, and get the old folks lo-
go around and see Smith about their precious boy. It will
make you, in the eyes of Smith, as large as Jumb ) to a rat.
When you worry your term of apprenticeship t!i rough
and you receive the title of jour., of course you demand jour.'s
wages, say as much as old man Stewpot. lie has worked
eighteen years in the shop, but that doesn't matter. Why,
you made six dozen joints of stove pipe in two hours and it
took him three.' Well, if you don't make satisfactory arrange--
ments, I heard Billy Doepan say that Enos Ket- 1,3, at Inkville,
wanted a man, and you, of course, strike; it pays bi^ wages to
o. first-class man. You go and see Kettle and he as' s you
what you can do. Of course you worked on the cornice for the
Grand Opera House, and on the button factory, r.nd several
other jobs too numerous to mention. You receive n position
to help Kettle out on the Green building cornice. Thi.> being
Thursday night, and hs has to go to Piumtoun to CIT. -n up a
job, he would like to have you come on m the morning. He
302
gives you a simple piece of cutting to keep you going until his
return-on Saturday night, when he makes a practice of paying
off his help. You come under this head, and find that he offers
you the enormous sum of seventy-five rents per day. and orders
the stove porter to go and cover the pig trough with your two
days' work to keep the pigs from making post holes ir iheir
trough, which his wife wanted him to do for the past nine
months. You declare he is a crank; you are going West, or
to some seaport town.
You strike out and get a position in a roofing shop paint-
ing tin. You write home to your brother chip telling what
a position you have, what big wrages, etc. , but not giving
original facts. In a few years you return home broken
down, with no trade. You can't demand a mechanic's
wages, and you look back and see your folly. How many
are there in this boat ? Boys, take my advice: Don't get
to knowing too much. Jf you get into that way, it is little
use for a mechanic to have anything to do with you.
THREE THERMOMETER SCALES.
Much annoyance is caused by the great difference in
thermometer scales in use in the different civilized countries.
The scale of Reaumur prevails in Germany. As is well known,
he divides the space between the freezing and boiling points
into 80°. France uses that of Celsius, who graduated his
scale on the decimal system. The most peculiar scale of all,
however, is that of Fahrenheit, a renowned German physi-
cist, who in 171401* 1715 composed his scale, having ascer-
tained that water can be cooled under the freezing point
without congealing. He therefore did not take the congeal-
ing point of water, which is uncertain, but composed a mix-
ture of equal parts of snow and salammonia, about — 14° R.
This scale is preferable to both those of Reaumur and Celsius,
or, as it is called, Centigrade, because : i. The regular tem-
peratures of the moderate zone move within its two zeros,
and can therefore be written without + or — . 2. The scale
is divided so finely that it is not necessary to use fractions,
when careful observations are to be made. These advan-
tages, although drawn into question by some, have been con-
sidered so weighty, that both Great Britain and America have
retained the scales, while the nations of the Continent use the
other two. The conversion of any one of these scales into
another is very simple. I. To change a temperature given
by Fahrenheit's scale into the same given by the Centigrade
scale, subtract 32° from Fahrenheit's degrees and multiply
303
the remainder by f . The product will be the temperature
in Centigrade degrees. To change from Fahrenheit's to
Reaumur's scale, subtract 32° from Fahrenheit's degrees, and
multiply the remainder by •$. The product will be the tem-
perature in Reaumur's degrees. 3. To change a temperature
given by the Centigrade scale into the same given by Fahren-
heit, multiply the Centigrade degrees by §, and add 32° to
the product. The sum will be the temperature by Fahren-
heit's scale. 4. To change from Reaumur's to Fahrenheit's
scale, multiply the degrees on Reaumur's scale by -J, and add
32° to the product. The sum will be the temperature by
Fahrenheit's scale. Following is a table giving the equiva-
lents in Centigrade, Reaumur and Fahrenheit, up to boiling
point, which will be a convenience to all readers who do not
like the labor of converting one scale to another :
C.
R,
F.
—30
— 24.0
— 22.0
—29
— 23.2
— 20.2
—28
—22.4
-I8.4
—27
—21.6
—16.6
—26
—20.8
—14.8
—25
— 20. 0
—13.0
—24
—19.2
— II. 2
—23
—18.4
—9.4
— 22
-17.6
-7.6
—21
— 16.8
-5.8
—2O
— 16.0
—4.0
— 19
—15.2
—2.2
— 1 8
—14.4
—0.4
—17
-13-6
1,4
— 16
— 12.8
3-2
—15
— I2.O
5-o
—14
—II. 2
6.8
—13
— IO.4
8.6
—12
— II
-9.6
-8.8
10.4
12.2
— IO
—8.0
I4.O
3
-7.2
-6.4
15.8
17.6
—7
-5.6
19.4
—6
—4.8
21.2
—5
— 4.0
23.0
—4
—3-2
24.8
—3
—2.4
26.6
~-2
—1.6
28.4
C.
8
9
10
ii
12
13
H
15
16
17
18
19
20
21
22
23
24
25
26
27
R.
F.
Up, 8
30.2
o.o
32.0
0.8
33.8
1.6
35.6
2.4
37.4
3-2
39-2
4.0
41.0
4.8
42.8
5-6
44.6
6.4
46.4
7.2
48.2
8.0
50.0
8.8
51.8
9.6
53-6
10.4
55-4
II. 2
57.2
12.0
59-o
12.8
60.8
43-6
62.6
144
64.4
15.2
66.2
16.0
68.0
16.8
69.8
17.6
71.6
18.4
73-4
19.2
75-2
20. o
77.0
20.8
21.6
78.8
80.6
304
c.
R.
F.
C.
R.
F.
28
22.4
82.4
65
52.0
149.0
29
23.2
81.2
66
52-8
150.8
3°
24.0
86.0
67
53-6
152.6
3»
24.8
87.8
68
54-4
154-4
32
25-6
89. 6
69
55-2
156.2
33
26.4
91.4
76
56.0
i5S.c
34
27.2
93-2
S6.8
159-8
35
28.0
95 o
72
57-6
161-6
36
28.8
96.8
73
163-4
37
29.6
98.6
74
59-2
165-2
38
30-4
too. 4
75
60.0
167-0
39
31.2
I O2. 2
76
(10.8
168-8
40
32.0
104.0
77
61 6
170-6
4*
32-8
105.8
78
624
1724
42
33-6
107.6
79
63.2
174.2
43
H-4
109.4
80
64.0
176.0
-14
35-2
III. 2
81
64.8
177.8
45
I 13.0
82
65.6
179.6
46
}6.8
114-8
83
66.4
181.4
47
37-6
116.6
84
67.2
1832
48
38.4
118.4
85
68.0
185.0
49
39-2
I 2O. 2
86
68.8
1 86. 8
5°
40.0
122.0
87
19.6
188.6
51
40.8
123.8
88
70.4
190.4
52
41.6
125.6
89
71.2
192.2
53
42-4
127.4
90
72.0
194.0
54
43-2
129.2
91
72.8.
195.8
55
44.0
I3I.O
92
73-6
197.6
56
44-8
132.8
93
74-4
199.4
57
45-6
134.6
94
75-2
201.2
58
46-4
95
76.0
2O3.O
59
47-2
J&2
90
76.8
204.8
60
48.0
140.0
97
7^.0
206.6
61
48.8
141.8
98
78.4
2O8.4
62
49-6
143.6
98
79.2
210.2
63
50-4
145-4
luO
80.0
212.0
64
51 2
147.2
WHY STEEL IS HARD TO WELD.
A metallurgist gives, as a reason why steel will not weld as
readily as wrought iron, that it is not partially composed of
cinder, as seems to be the case with wrought iron, which
assists in forming a fusible alloy with the scale of oxidation on
the surface of the iron in the furnace.
305
DIFFERENT COLORS OF IRON, CAUSED BY
HEAT.
Deg.
Cen.
Deg.
Fah.
261
502
f Violet, purple and dull blue.
1 Between 261° C. to 370° C. it
370
680
^ passes to bright blue sea
[_ green, and then disappears.
f Commences (o be covered
| with a light coating of ox-
500
932
<j ide ; becomes a deal more
j impressible to the hammer,
( and can be twisteel with ease.
525
977
Becomes a nascent red.
700
I2Q2
Somber red.
800
1472
Nascent cherry.
900
1657
C herry.
1000
1832
Bright cherry.
IIOO
2OI2
i hill orange.
I2OO
2192
Bright orange.
1300
2.372
White.
1400
2552
Brilliant white-welding heat.
1500
1600
2732
291^
- Dazzling white.
TO DRAW FERRULES.
A useful tool for drawing thimbles or ferrules out of loco-
motive boiler tubes
is here shown. It is
an English inven-
tion, and it is not
stated that it is pat-
ented. The tube A
is split in quarters on
the enel so that it
can be easily slipped
in. The rest of the
device explains itself,
as does the sev ond figure also, which IP another device for the
same purpose.
306
BELTING SHAFTING AT EIGHT ANGLES.
vn Fig. 1 of the illustration, A is the driver. The belt
leaves the pulley at C, goes to the driven pulley, and then
down to the driver at h. In Fig. 2 this movement is re-
Fig. i. Fig. 2.
versed. Fig. 3 is a side view of the driven pulley Z?, and Fig.
4 shows the driving pulley A, with the driven pulley B in-
side, so as to run in the one direction, while the dotted linesf
Show B outside, so as to run the opposite way. Figs, i and t
show that centers of the faces of both pulleys must be in line
307
with each other, and if this point is attended to the pulleys
will run well together, although they may be of different
diameters.
AN EASY WAY TO LEVEL SHAFTING.
The device here illustrated for leveling shafting I have
found to be very handy. The hangers A. are made of wood
and are cut at an angle of 45 o at the top end, so that they will
fit different sized shafts, and a slot is cut at (a) to receive the
straight edge C. The hangers are placed on the shaft to be
tried, at any convenient place as near the bearings as possi-
ble, and the straight edge placed in the slots, in which it
should fit tight. Then by placing the spirit level D on the
parallel part of the straight edge, it \vill be seen whether the
shaft is level or not. It is best ff the hangers be made of
hard wood.
A SELF-WINDING CLOCK MOVEMENT.
A self-winding clock is now on the market and we present
herewith an engraving of one. It is made by the American
Manufacturing and Supply Co., Limited, 10 and 12 De$r
street, New York. Objection may be made to the employ-
ment of a battery as an auxiliary, and therefore that the clock
Is not self-winding, but the office of the battery is secendaij;
the operation of the clock opening the circuit while the bat-
tery is used only to interrupt it. Appended is a description
Of the movement:
The wheels and arbors below the center are removed from
the clock. In their place a small electric motor is substituted.
This motor connects with a spring barrel on the center arbor,
which incloses a spring six feet long, three-sixteenths of an
inch in widtft and six-one-thousandths of an inch in
thickness. This spring, at its inner end, is attached
309
to the arbor, and at the ou.ef end to the periphery of the
^pring barrel. The spring is coiled around the arbor many
times, but not so close as to 'produce friction between the
Coils; and being attached to the center arbor it follows that
the inner end will unwind one turn every hour. By a sim-
ple attachment the electric circuit is made to pass into the
motor already referred to, which quickly carries the spring
barrel around once (being free on the arbor), and the outer
end of the spring attached to its periphery with it. Upon
the completion of one revolution of the spring barrel, as de-
scribed, the electric circuit is broken and the motor stops.
By this arrangement it will be observed that the inner end of
the spring always has a motion from left to right, or in the
direction the hands are moving, and the outer end of the
spring a motion in the same direction when the clock is
being wound.
Now, since the winding is done in the same direction as
the unwinding of the inner end, and the spring is SO wound
originally as to avoid friction between the coils, it follows
that the tension upon the train is absolutely uniform at all
times whether the outer end of the spring is at a point of tem-
porary rest or is being carried around the arbor at the time
of winding, as above "described. By actual experiment it is
found that to obtain a given force at the escape wheel it is
only necessary to apply a power in this manner at the center
arbor equal to less than one forty-sixth part of that used in
the ordinary clock. The train work is not only shortened
one-half, but the fricfion on the remainder is reduced in the
proportion stated.
The invention lies in bringing a motor and clock-work
together in a time piece, and is not limited to any particular
device. Experiments prove that a motor as constructed for
this purpose can be run for one year at an expense of less
than twenty-five cents; hence a clock may be sealed up and
left to itself for a period of at least one year with a certainty
of closer time during that period than can be secured by any
other known method of giving time. In short, a common
clock constructed on this principle has been found to keep as
accurate time as one of the higher grades with gravity
escapements, etc., run by the old methods. The electric
motor is normally out of circuit, but at stated intervals, by
the operation of the clock itself, the circuit is completed and
the motor is thus set in motion. To be more exact we will
give a general description of the mechanism employed in the
clock. Upon the center arbor there is placed a loose " arm M
between the hour wheel and the wheel carrying the spring
'oox. At one side of one of the " train plates " is secured
an insulated spring connector, Jhe free end of which extends
to, and is within reach of, the " arm," when the same has been
brought to a perpendicular position, which is done by means
of a pin projecting from the hour wheel.
When the hour wheel has thus brought the " arm" to an
jpright position and in contact with the insulated spring
connector, the circuit is completed through the motor, which
at once commences to rotate the spring box one revolution
from left to right, or in the direction that the hp.nds move.
Tbe spring box wheel also carries a projecting pin, but set at
aiCos «-'».'. i<a<?e fro^i tb.e rods than the other pin. Now, as
the motor continues cc* ,.—-.Jj? *'•*? wing box wheel, while
the spring connector is resting upon the "arm," it follows
that as soon as there has been one revolution of the spring
box wheel the projecting pin upon this wheel will press the
"arm" forward and out from under the spring connector,
thereby breaking the circuit and stopping the motor. This
arrangement prevents the possibility of the clock] running
b-yond the regular limit for winding, and prevents the motor
when once set in operation from performing more than the
work required.
TESTS OF STEEL PIPE.
The Riverside Iron Works, of Wheeling, W. Va., has
carried out a series of interesting experiments to ascertain
the relative corrosive action of water acidulated with nitric
acid upon iron and steel plates cut from pipe. The water
was acidulated with one part of strong nitric acid in ninety
parts, the plates being of the same dimensions, free from
scale and grease and polished bright. In each case the
pieces cut from iron and steel pipe were hung side by side in
the same acidulated water, the loss of weight being deter-
mined at the end of twenty-four and of forty-eight hours.
One test was made by exposing both surfaces and edges to
the action of dilute acid, the result being that the loss in
grains after twenty-four hours was 3. 6 in the case of iron
from standard iron pipe, and 1. 15, or less than half, with steel
pipe. In forty-eight hours the figures stood 6. 53 and 2.21
grains, respectively. In a second test the edges of the pieces
were protected from the action of the acid and the two oppo-
site sides only exposed. In this test the loss of iron after
twenty-four hours was 1.89 grains^ against 0.49 grains with
the steel, and after forty-eight hours 4.28 and 1.24, respect-
ively. The dimensions of the test-pieces were i]^. ;nches
3U
square by 3-16-inch thick. A series >. " comparative tests
have also been made to ascertain the rela\ ^ strength of the
weld of Riverside steel and standard iron x *£*>. Two test-
pieces were cut from Riverside pipe, mechanv^i lap-weld,
with the weld at the middle, and in a similar *r*v from
mechanical lap welded iron pipe, in each case with \ weld
in the middle. Not one of the tests broke at the we'K *he
steel showing a tensile strength of 52,400 and 66,330 pou*
with an elongation of 18.75 and 17.25 per cent in 8 inches
while the iron pipe samples showed 62,480 and 35,240 pounds
per square inch, and an elongation of 2.25 and 0.50 per cent
Two samples from a sheet of Riverside steel lap- welded by
hand, with the weld in the middle, showed a tensile strength
of 51,860 pounds, and an elongation of 7 per cent, in 8
inches, the fracture occurring at the weld. A second sample
had an ultimate strength of 56,090 pounds, elongation 13
per cent, and did not break at the weld. Iron plates cut with
the grain and hand-welded have a tensile strength of 44,630
and 43,500 pounds, respectively, with an elongation of 5 and
4.25 per cent., both breaking at the weld.
TOOL FOR COUNTER-BORING.
The above is a sketch of a tool that will be found very con-
venient on many occasions, when
counter-boring work in the [drill
press; usually such work is done with
a cutter of the same shape as it is
desired to have the finished work,
when if there is any scale, as in cast
iron, it is very difficult to get the cut-
ter started. The tool in the sketch
entirely obviates that difficulty, as
only the points come in contact with
the scale at first and are easily forced
through it. Referring to the sketch,
A is the end of a cutter-bar, B, the
cutter, and C, the wedge for keeping
the cutter in place. It will be
noticed that the teeth D, on one side
of the bar will, as it is" revolved,
cover the space left by the part of
the cutter on the other side of the
bar, and thus rapidly remove the
scale and metal, when the work
may be finished by the ordinary flat
cutter.
HO^V TO MAKE A SMALL STORAGE LATTERY.
A storage battery, or accumulator, to light an incandes-
cent lamp of 4 candle-power, would not jgo in an ordinary
sized pocket, because one would require at least four cells,
and if the plates were made too small, the charge put into
them would last scarcely a few seconds. The following di-
rections will enable any person to construct a storage bat-
tery, which, when charged, will light a 4-volt lamp.
The first thing to do is to procure of some dealer in elec-
trical apparatus and material a hard rubber cell, about $}4
inches by 5 inches by i inch, having two compartments of
equal dimensions. Such a cell can be purchased for about
fifty cento.
Next, cut four plates from one-sixteenth inch sheet lead,
4% inches by i^ inch, having an ear to each; punch as
many holes in each plate as you can to within ^ inch from
the ear or top end. Then fill up the holes, and also smear
the plates with a thick paste of red lead (minimum) and di-
luted sulphuric acid. Cut out a piece from thin — >g of an
inch — hard wood, 3^ inches long and i inch wide ; pierce
it with four s its large enough to allow the ears of the plates
to come through (two to each cell), and, also, where con-
venient, two holes s!:ou!d be made and fitted with glass tubes
for the purpose of fiiiing the cells.
As s ion as the rod lead paste has become hard, plac thee
four p!a'es i \ their positions, and solder the ear of one plate
to the ear piece of the next cell. This will leave cue free end
from each cell; to these a wire or terminal should be sol-
dered. Now cement on the top and cover all over, except
the g^ss tubes, wit'1 a composition of one part melted pitch
and two par's of gutta-percfia,
Having filled the eel's three-quarters full with a 10 per
cent, solution of sulphuric acid, connect the wires on a
primary battery or s nail dynamo. Charge, discharge and
reverse every three hours, and let the last charge remain in
all night. Do this till you find your storage battery will
ring a bell, with fifteen minutes' charging, for about ten.
Then only charge one way, and mark the ends in some way.
so as to know where to connect one next time lor charging.
This battery, when completed, will light a 3 or 4 volt
iamp well during intervals for about two hours. A similar
cell, having four compartments instead of two, would suffice
to operate an 8 or 9 volt lamp, or one of about 6 candle-
Dower.
Such a battery as has just been described may be
veniently be formed by a ten-cell Daniel telegraph battery in
about a fortnight's time.
A storage battery of this size should never be charged
until within an hour or so of its being wanted for use, as it
will run down a little by short circuiting, owing to the damp-
ness of the inside.
Finally, it should be stated, that, before putting the plates
in the cells for good, a piece of india rubber ought to be
placed between the plates, as well as a piece on the two out-
sides, and held by a piece of asbestos fiber. This prevents the
plates from touching each other, and also keeps them from
shaking from side to side.
LUBRICATING WITHOUT OIL.
Several interesting facts in regard to cylinder lubrication
were brought out at the recent meeting of the American
Society of Mechanical Engineers, a'. Philadelphia. Among
other things Mr. Denton stated as b s opinion that the fric-
tion of an engine was independent of the lead, and, among
other things, presented the subjoined interesting table:
Indicated II. P.
Friction,
H. P. Kind of engine.
84
7
10
5
5-i
44
40
'9
25
{
\
I
\
\
Westinghouse,
I2xu inches,
300 revolut's.
Buckeye, 7x14
inches, 280 re-
volutions.
Compound con-
densing throt-
tled.
Compound con-
d e n s i n g- ex-
pans ion.
Unloaded
23 ....... ...
Unloaded
"347. .
185
181
I 27. .
This table, it will be observed, shows that the friction is
actually less in all cases but one when the load is greatest.
Mr. Denton thought that the friction of a piston in a cyl-
inder was slight, and that lubrication did not bring about any
noticeable result so far as this particular part was concerned.
In support of these statements he cited first the case of aa
engine in which the steam of the same pressure was admitted
to both cylinder ends at the same time The difference in
area between the two faces of the piston nwingr to the pres-
ence of the piston-rod, and the conseciu^ntly greater effective
3H
pressure on the back, as compared with the frc ^ace, caused
the piston to move slowly to the front end of tv Cylinder.
The friction, therefore, could not have been appreci. . \. As
regards lubrication Mr. Denton gave an accoun! O his
experience with engines which had been cleaned out v>th
ether, and in which no oil whatever had been used for monthfc
The records obtained under such conditions, when compared
with data from the same engines using oil in the cylinders,
showed no difference worthy of special note. The fact that
engines showed less friction under the heavier loads than
under the lighter ones Mr. Denton explained by the assump-
tion that the various journals, through the reversal of motion
of the reciprocating parts of the engines, developed a suc-
tion-pump action, drawing in the lubricating oil, and that
this action was more vigorous when the engines were fully
loaded.
CALKING.
Calking is something that is not always done as it should
be. In fact, in some sections of the country it is done as it
shouldn't be, about as emphatically as it is possible to do any-
thing. The thing most particularly referred to in this con-
nection, and the practice of which should bankrupt any
boilermaker, is known as " split calking." To do calk-
ing in the best manner, and as it should be done, the edges
of the plates should be planed. They are planed in all first-
class shops, and trouble caused by bad calking is something
very rare with such work. But of course this refers to new
work. Repair jobs, and boiler work turned out of the shops
in remote sections of the country where planers are unknown,
afford the demon of split calking a chance to get in his most
effective work. He rarely neglects a chance that is offered
him. Some one may inquire, what is split calking? To
which we would reply, split calking consists in driving a thin
caulking tool, scarcely one-sixteenth of an inch thick, against
the- edge of a sheet so that a thin section of the plate is
driven in between the two plates, with the idea of making a
joint tight. The result generally is that the plates are sepa-
rated from the edge of the lap back to the line of rivets, some-
times as much as one-thirty-second of an inch, the only bear-
ing surface outside of the rivets being the portion split off
from the plate and driven in by the calking tool. This
bearing surface may be an eighth of an inch wide, but it is
apt to be much less, and no patent medicine yet discovered
will keep the seam tight for any length of time. When a
boiler thus calked gets to leaking so badly that it can't be
run, the boiler-maker is sent for, and he usually proceeds to
do more split calking, and in a short time the boiler leaks
worse than ever. In one instance one of our inspectors
examined a boiler and found one of the girth seams leaking
badly. It had repeatedly been calked in the above manner;
so many times, in fact, had the process been repeated, that
there was not enough of the Jap to perform another opera-
tion on. He, therefore, gave instructions for putting on a
patch, with a special caution to the owner, to whom he ex-
plained the cause of the trouble, to allow no split calking to
be done on it. On his next visit he examined the patch, and
he declares that the boiler-maker had put in on it the worst
job of split calking he ever saw in his life.
USEFUL NUMBERS.
3.l4i5926=ratio of diameter to circumference of circle.
.y854=ratio of area of circle to square of its diameter.
33,000 minute foot pounds=i HP.
396,000 minute inch pounds=i HP.
396,000 cubic inches piston displacement per minute of
engine wheel would develop I HP. with I Ib. mean elective
pressure on the piston.
23,760,000 cubic inches piston displacement p^r hour of
engine developing i HP. with i Ib. mean effective pressure on
the piston.
859,375 pounds of water per hour at i tt>. pressure pei
square inch to give i HP.
55 Ibs. mean effective pressure at 600 feet piston speed
gives i HP. for each square inch of piston area.
0.301030=^111^ logarithm 2.
0.477121 " ^ u 3
0.602060 4.
0.698970 " 5.
0.778151 fc 6.
0.845098 «• " 7.
0.903090 " ** 8.
0.954243 " 9-
I.OOOOOO " IO.
2.3025851 times natural logarithm gives hyperbolic log-
arithm.
.5000000= sine of 30° with radius i.
.7071068 " 45° " i.
.8660254 " 60° « i.
9,000 to 13,000 feet per minute velocity of circular sa\\
him.
27,000 tbs. per square inch tensile strength of cast iron.
50,000 tr>s. per square inch tensile strength bf •wrought
iron.
130,000 lt>s. tensile strength of steel.
30,000 Ibs. tensile -strength of sheet copper.
60,000 Ibs. tensile strength of copper wire.
100,000 Ibs. per square inch==crusning strength of cast
iron.
35,000 Tbs. per square inch=crushing strength of wrought
iron.
225,000 Ibs. crushing strength of steel.
300 to 1,200 tons per square foot crushing strength of
granite.
6.500 Ibs. per square inch ci u.shing strength of oak.
(Above crushing strengths are for pieces not over 3 dia-
meters in length. )
600 to 1,000 feet per minute of single leather belt I inck
wide said to give i HP. on cast iron pulleys.
2.645 IDS> Per lineal foot of I inch round wrought iron.
3.368 Ibs. per lineal foot of I inch square wrought iron.
40 Ibs. per square foot of i inch plate wrought iron.
2.45 Ibs. per lineal foot of I inch round cast iron.
12 times weight of pine pattern — iron casting.
13 times weight of pine pattern = brass casting.
19 times weight of pine pattern —lead casting.
12.2 times weight of pine pattern —tin casting.
11.4 times weight of pine pattern =zinc casting.
.06363 times square of inches diameter, times thickness in
inches = weight of grindstone in pounds.
.8862 times cliam. of circle —side of a square equaling.
.7071 times diam. of circle =side of inscribed square.
1.1283 times square root of area of circle =diam. of circle.
57° 2958 in. arc having length = radius
•oi745^X radius=length of arc i deg.
9.8696044=3. 14i5926* = fi*.
1.7724538= \r (3. 1415926)= vn.
o.497i5=nat. log. 3.1415926.
i
. 31831 =reciprocal of 3. 1415926=—
it
.002/78=1-7-360=1-360.
114.59=360^-3.1415926.
3i83Xcircumf. =diam. of circle.
2786° F. =melting point of iron.
2016° F.=melting point of gold.
1873° F.=melting point of silver.
2160° F.=melting point of copper.
74°° F.=melting point of zinc.
620° F.— melting point of lead.
475° F.=melting point of tin.
537 Ibs. per cu. ft.=
450 Ibs. per cu. ft. =
485 Ibs. per cu. ft. =
708 Ibs. per cu. ft.=
490 Ibs. per cu. ft.=
'eight of copper,
veight of cast iron,
veight of wrought iron.
v eight (T cast lead.
v eight of steel.
27.684 cubic inches of wa er p-jr pound at 32° F
27.759011. in. water p-?r li>. at 70°
036 Ibs. par cu. in. water at 60° F.
62.355 Ibs per cu. ft. water at 62 ° F.
59.64 Ib.s per cu. ft. water at 212 ° F.
.54 Ibs. anthracite per cu. ft.
40 to 43 cu. ft. anthracite per ton
49 cu. ft. bituminous coal per ton.
39.3685 inches = I meter.
3.2807 feet = i meter.
1.0936 yards = I meter.
61.02 cubic inches = i meter.
2.113 pints = i liter.
1.057 (marts -— I liter.
BUYING OIL AND COAL.
There arc many establishments which, when buying oil,
coal, and such supplies, consider merely the question of first
cost irrespective of their economic value. The best is not
necessarily the cheapest, nor is it necessarily the dearest.
The true economic value is due to the service it will per-
foivn, divided by the price.
We will take the case of coal. Some coal will evaporate
ten pounds of water per pound of coal under certain condi-
tions, and others only seven. In the one case there will be
2240X10—22,403 pounds of water evaporated, and in the
other only 2240X7=15,680 pounds, under the same condi-
tions. If the first lot sold at $5.25 per ton, and the second
at only $5 the first would be the cheapest, for in the one case
(including freight and labor in stoking and cost of remov-
ing ashes) we would get 22,400-7-5.25=4,266.66 pounds of
steam per d jllar's worth of co:il, and in the other only
I "5,680-7-5— 3, 136 pounds of steam per dollar's worth of coal.
Not allowing for freight and the cost of removing ashes, and
Hot considering the capacity of the boiler with good coal as
compared with its capacity with poor, the first coal would be
a schcap at $6.80 per ton as the second at $5 ; or, to put
it the Other way, the poorer coal ought 10 be sold at $3.85
per ton to make it as cheap as the better material at $5.25.
When the other expenses are taken into consideration, the
economy of buying the better coal becomes greater.
In the matter of oils: these vary in their lubricating
powers, in their coolness of running, and in their durability.
We will consider two oils, one at 25 cents per gallon and the
other at 30, having the same lubricating power and running
equally cool under fee feed, but one requiring 100 gallons to
keep the friction down to a minimum and the other taking
onty 75 gallons to effect the same object. The relative
economy of these two oils is not as 30 to 25, or as 120 to 100,
but as 30X75=2,250 to 25X100=2,500, or as 100 to 90;
that is, the cost of the high-priced oil to effect a given desired
condition is only .90 the cost of the poor oil to do the same
thing ; then the economy is as 100 to 90. At this rate the
better grade of oil would be as cheap at
ioX30_
7~~ =:33/i cents per gallon,
as the cheaper at 25 cents ; or the lower grade would havp
to be sold at
9x25
— 22 ^ cents per gallon,
to bring its economy down to that of the better grade ; and
this without counting freight, which, in many cases, should
be added to the invoice price, or time in oiling, which is time
lost.
NOTES ON PATTERN-MAKING.
Never work with a dull tool.
Take time to sharpen and put your tools in good order; it
saves time in the end.
Above all, never use a dull or badly " set " saw. It will
ruin your work, sour your temper, and make you disgusted
with the whole world.
If you are varnishing or polishing a piece of work, have
the room or shop warm, exclude draught and dust, and don't
be in too big a hurry.
If you are polishing in the lathe, see to it that all dust
and dirt are removed from the lathe-bed before you com-
mence work.
It is better, when possible, to polish all turned work in
the lathe. It always has a better appearance for it.
In making patterns for castings, if you have no experience
319
you had better consult some person who has had experience.
Patterns are difficult things for amateurs to make if they do
not understand the principles of molding and founding.
White pine or mahogany makes the best work for pat-
terns. Lead, brass, copper and sometimes plaster of Paris
are used for making patterns; especially is this so for small
fine castings.
Shellac varnish is the best material for coating pat-
terns.
Beeswax may be used for stopping up holes or to cover
defects in patterns if it is coated with shellac varnish after-
ward. The beeswax will " take " the varnish readily, and
will not cling to the ''sand," like ordinary putty.
Shellac varnish may be mixed with a little lampblack to
give it body and make a black pattern.
Sometimes pattern-makers use stove polish or "black
lead," as it is called, to finish their patterns. It is applied
nearly dry, then polished with a brush.
Wood used for patterns must be of the very best finish,
straight grained, free from knots or shakes, and well sea-
soned.
A clean pattern gives n clean casting, and much labor
may be saved by making the pattern the right size, and
smooth and clean.
After patterns have been used they should be kept in a
dry pb.ce, as damp will distort and otherwise injure them.
Always make a drawing of patterns before making. Much
time and labor will be saved.
Where patterns part in the center they should be made
to separate easily.
Put on your best workmanship when pattern making.
AN INTERESTING EXPERIMENT.
You think you stand pretty straight, don't you? Well,
just back up against the wall of a room and bear against it
all over ; you will find there more buckles, short bends and
offsets between your head and your heels than you had any
idea of.
While you have your heels against, the baseboard, keep
them there, and reach over forward and touch your fingers to
the floor, if you want a specimen of upset gravity.
A steel wire nail mill has just begun work at Hamilton,
Ont. The output at present is a ton a day.
320
THINGS TO REMEMBER ABOUT SHAFTING.
Don't buy light hangers, and think that they will do well
enough, when your own judgment tells you that they will
spring.
Remember that shafting is turned one-sixteenth inch
smaller than the nominal size.
Cold-rolled and hot-rolled shafting can be obtained Tie
full size.
The sizes of shafting vary by quarter inches up to uiree-
and-a-half inches.
The ordinary run. of shafting is not manufactured longer
than from 1 8 to 26 feet.
For line shafts, never use any that is smaller than one-
and-eleven-sixteentli inches in diameter, as the smallest
diameters are not strong enough to withstand the strain of
the belts without springing.
The economical speed of shafting for machine shops has
been found to be from 125 to 150 revolutions per minute,
and for woodworking shops from 200 to 300 revolutions.
A jack-shaft is a shaft that is us^d to receive the entire
power direct from the engine or other motor, which it delivers
to the various main shafts.
Keep the shafting well lined up at all times, as this will
ward off a breakdown, and avoid a waste of power.
Know that the pulleys are well balanced before they are
put in position, as a pulley much out of balance is quite a
sure method to throw shafting out of line.
Look to the pulleys, and see that they have been bored to
the size of the shaft, for unless this is done the pulley may be
out of center on the shaft and prevent smooth running.
If possible, apply the power to a line of shqftingat or near
the center of its length, as this will enable you to use the
lightest possible weight of shafting.
Hangers with adjustable boxes will be found to be the
most convenient for keeping the shafting in line.
Keep your drip-cups cleaned, and Jo not allow them to
overflow or get loose.
Have a supply of tallow in the boxes ; in case of acciden-
tal heating it will melt and prevent cutting ; this rule, while
good for general use, applies particularly to special cases where
there is a supposed liability to heating.
Never lay tools or other things on belts that are standing
Still, for they may I e forgotten and cause a breakdown when
the machinery is started.
Don't attempt to run a shaft in a box that is too larre .>r
321
too small, as you will waste time and fail to secure good re-
sults.
A loose collar held by a set screw will cause the collar
to stand askew, and it will cut and wear the box against
whick it runs.
In erecting a line of shafting, the largest sections should
be placed at the point where the power is applied. The
diameter can then be gradually decreased toward the extrem-
ities remote from this point.
Don't put loose bolts in plate couplings, as this will give
no end of trouble in cutting, shearing and the wearing away
of the bolt holes.
Don't think that because your shafting has been well
erected and you oil it regularly, that it will never need any
inspection or repairs.
Don't try to economize in first cost by having long dis-
tances between hangers, for a well supported shaft will
always do the best work ; short shafts are the surest to be
straight and to remain so, (
The length usually adopted for shafting bearings is twice
to four times the diameter of the shaft, varying with the
diameters of shaft, kind of bearings and the material used in
them. Large shafts- in the gun-metal or bronze boxes may
have bearings only twice theii diameter in length. Cast iron
bearings up to and including three inch shafts are often made
four diameters of the shaft in length, particularly for self-
adjusting hangers.
If Babbit is used for the boxes, use only a good metal;
do not adopt the common mixture of tin, antimony and
lead.
Insist upon having good iron in your shafting, as the
bearings will take a finer polish, and you will not be subject
to sudden ruptures.
If the strain on a pulley is so great that the set-screws
already in will not hold it, d'o not let them score into the
shaft, but put in an extra screw, or cut a key- way and put in
a key. «
The width of a key-way should be one-quarter of an inch
fort^Ci* inch of diameter of the shaft.
The depth of a key-way is one-half its width.
322
WORKSHOP JOTTINGS.
To Prepare Zinc for Put tiling — Apply sulphuric acid
and water for a quarter of an hour ; then wash off clean with
water and dry.
Moisture-Resisting Glue — A glue which is proof againsj
moisture may be made by dissolving 16 ounces of glue in 3
pinte of skim milk. If a stronger glue be wanted, add
powdered lime.
A Good Lubricator — It may not be generally known that
tallow and plumbago thoroughly mixed make the best lubri.
cator for surfaces when one is wood or when both are wood.
Oil is not so good as tallow to mix with plumbago for the
lubrication of wooden surfaces, because oil penetrates and
saturates the wood to a greater degree than tallow, causing it
to swell more.
To Prevent Metals jRusttng—The following is said to
be a good application to prevent metals rusting : Melt I oz.
of resin in a gill of linseed oil, and while hot mix with it two
quarts of kerosene oil. This can be kept ready to apply at
any time with a brush or rag to any tools or implements
required to lay by for a time, preventing any rust, and saving
much vexation when the tool is to be used again.
7*o Prei>ent Slipping of Belts — Belts conveying power
are very apt to slip on pulleys, but a new pulley has been
devised to prevent this. The pulley is covered with per-
forated sheet iron one-sixteenth of an inch thick, which is
riveted to the pulley. The tension of the belt causes it to
grip slightly the holes, and thus slipping is avoided, while at
the same time the pulley is strengthened.
To Calculate Water in a Pipe — To calculate roughly the
quantity of water in any given pipe or other cylindrical ves-
sel, it is only necessary to remember that a pipe one yard, or
three feet, long will hold about as many pounds of water as
the square of its diameter in inches. Thus: If we have a
pipe 20 inches in diameter and 16 feet long, we have simply
to square 20 (2O2— 400), and multiply the result by the
number of times 3 feet is contained in 16 feet=5X times;
hence, 400x5^=2,133 pounds. By increasing the result by
2 per cent., or i-5Oth, a more nearly exact figure can be
obtained.
323
BRASS AND ITS TREATMENT.
Brass, as previously stated, is perhaps the best known and
most useful alloy. It is formed by fusing together copper ^
and zinc. Different proportions of these metals produce
brasses possessing very marked distinctive properties. The
portions of the different ingredients are seldom precisely alike;
these depend upon the requirements of various uses for which
the alloys are intended. Peculiar qualities of the constituent
metals also exercise considerable influence on the results.
Brass is fabled to hivebeen first accidental'y formed at the
burning of Corinth, 146 B. C, but articles of brass have been
discovered in the Egyptian tombs, which prove it to have had
a much greater antiquity. Brass was known to the ancients
as a more valuable kind of copper. The yellow color was con-
sidered a natural quality, and was not supposed to indicate an
alloy. Certain mines were much valued, as they yielded this
gold-colored copper, but after a time it was found that by
melting copper with a certain earth (calamine), the copper
was changed in color. The nature of the change was still
unsuspected.
Alloy of copper and zinc retain their malleability and
ductility when the zinc is not above 33 to 40 per. cent, of the
alloy. When the zinc is in excess of this, crystalline character
begins to prevail. An alloy of one copper to two zinc may
be crumbled in a mortar when cold.
Yellow brass that files and turns well may consist of cop-
per 4, zinc i to 2. A greater proportion of zinc makes it
harder and less tractable; with less zinc it is more tenacious
and hangs to the file like copper. Yellow brass (copper 2,
zinc i) is hardened by the addition of two to three per cent,
of tin, or made more malleable by the same proportion of
lead.
There would be less diversity in the results of brass cast-
ings if what was put in a crucible came out of it. The vola-
tility of some metals, and the varied melting points of others
in the same mix, greatly interfere with the uniformity in
ordinary work. Zinc sublimes (burns away) at 773 to 800
degrees, while the melting heat of the copper — with which it
should be intimately mixed in making brass — is nearly 1,750
degrees. Copper, zinc, tin and lead in varying proportions
form alloys, always in definite quantity for a given alloy.
The ease with which some of the metals are burned away at
comparatively low temperatures renders it a very easy mat-
ter to make several different kinds of metal with*the same
mix. T nls very thing occurs, and the great difficulty in get.
324
ting bearing brasses uniform in quality causes some engineers
to babbitt all bearings as the best way to insure uniformity.
One lot of castings may VJe soft and tough, another hard,-'
and so on. ^
Zinc is added the last thing as the crucible comes out of
the furnace, and the mixing of the mass is a matter of uncer-
tainty. If the metal Is too hot for the zinc a large percent-
age goes off in the form of a greenish cloud of vapor, and
the longer the stirring goes on the more escapes. The two
metals which enter into the composition of brass have an
affinity for each other, but they must be brought into inti-
mate contact before they will combine. Some brass founders
use precautions to prevent volatilization of the more fusible
metals, introducing them under a cover }f powdered charcoal
on top of the copper.
" Brass finisher " is a term many understand as applied
only to those who produce highly-finished brass work ; but it is
not so ; the brass finisher's work is not the superior class of
work supposed, most of it toing comprised in gas fittings,
ormolu mounts, etc., but the Highest class of brass finishing
is a totally different process. Fittings for gas work, all
finished well enough for their several purposes, and as well
done as the price paid for them will allow, as well as the
mountings for furniture, must obviously be produced at a lo\\
price, in order to supply the demand for cheap work of this
character, most of which is simply dipping, burnishing and
lacquering.
Let us follow the process of finishing the highest class of
brass work. Before commencing to polish, all marks of the
file must be removed, and this is clone thus : Having used a
superfine Lancashire file to smooth both the edges and surfaces,
take a piece of moderately fine emery paper and wrap it
tightly, once only, round the file. By having many folds
round' the file the work becomes rounded at the edges,
and so made to look like second-rate things. Some use
emery sticks, made of pieces of planed wood about ft
inch thick and ^ inch wide, quite flat on the surfaces.
They are covered with thin glue, and the emery powdered onto
them, and then allowed to dry hard. Most common work
is rubbed over, not to say finished, with emery cloth. This
will not do for good work. The paper folded once round
the file is used in a similar manner to the file, and when the
file-marks disappear, and the paper is worn, a little oil is
used, which makes it cut smoother. Tphe edges and surfaces
being prepared to this extent, tite cjges must be finished.
To effect this take a piece of flat, soft wood, and apply t > its
325
surface a little fine oil-stone powder; be sure that, it is quite
clean, as it is very annoying to make a deep scratch in the
work just as it is finished; perhaps so deep that it -will re-
quire filing out.
FACTS ABOUT A WATCH.
The watch carried by the average man is composed of
ninety eight pieces, and its manufacture embraces more
than 2,000 distinct and separate operations. Some of the
smaller screws are so minute that the unaided eye cannot
distinguish them from steel filing or specks of dirt. Under
a magnifying glass a perfect screw is revealed. The slit in
the head is two one-thousandths of an inch wide. It takes
308.000 of these screws to weigh a pound, and a pound is
worth $1,585. The hairspring is a strip of the finest steel,
about 9l/z inches long, and one-hundredth inch wide and
twenty-seven ten-thousandths inch thick. It is coiled up in
a spiral form and finely tempered.
The process of tempering these springs was long held us a
secret by the few fortunate ones possessing it, and even now
it is not generally known. Their manufacture requires
great skill and care. The strip is gauged to twenty one-
thousandths of an inch, but no measuring instrument has
yet been devised capable of fine enough gauging to deter-
mine beforehand by the size of the strip what the strength
of the finished spring will be. A twenty one-thousandth
part of an inch difference in the thickness of the stop makes
a difference in the running of a watch of about six minutes
an hour.
The value of these springs, when finished and placed in
watches, is enormous in proportion to the material from
which they are made. A comparison will give a good idea.
A ton of steel made up into hairsprings when in watches is
worth more than 12^ times the value of the same weight in
pure e-old. Hairspring wire weighs 1-20 of a grain to an
inch. One mile of wire weighs less than half a pound. The
balance gives five vibrations every second, 300 every min-
ute, 18,000 every hour. 432,000 every day and 157,680,000
every year. At each vibration it rotates about 1*4 times,
which makes 197.100,000 revolutions every year.
In order that we may better Understand the ^stupendous
amount of labor nerformed by these tiny works, let us make
a pertinent comparison. Take, for instance, a locomotive
with six-foot driving wheels. Let its wheels be run until
they have given the same number of revolutions that a
watch does in one year, and they will have covered a dis-
tance equal to 28 complete circuits of the earth. All this a
watch does without other attention than winding once every
24 hours.
Fig. i.
326
METAL- WORKING DIES AND THEIR USES.
BY HENRY LONG.
In the following pages, which have been specially prepared
for this work, will be found a condensed description of the
commoner kinds of dies now in use for sheet-metal work.
There being several kinds of punching presses, I will specify
the variety in which each die can be used as I describe it.
The commonest in use is the simple cutting-die, and I will
describe it first. It can either
be made by welding a steel ring
of the shape desired on a
wrought iron plate, and then
dressing the hole out roughly
to pattern while hot, or by
drilling out a hole of the shape
required through a piece of
flat steel of proper dimensions,
i and then dressing it out with
' files, etc., to exact size. While
the former plan is most expen-
sive, it is the best in regard to
wear and quality of work. Fig. i represents a die of this
kind. The forging for this die would be made as I explained
above; that is, by welding a steel ring of the shape of
the pattern on an iron plate, and cutting the hole
through the iron afterward. The punch for this would be
made simi'arly, only, that the ring is the shape of pattern
outside, and after welding to the iron plate it is trimmed off
outside. There is also a shank to be welded on the other side
of plate, as nearly central as possible, and large enough to
finish up easily to size required. In making this die the two
faces are planed off clean, and then the pattern is laid on top
face and the die is marked from it. When this is done, it is
put in the shaper and planed out to the marks, care being
taken to throw the work forward in the chuck to give about
/g- in. clearance to the inch, in depth.
It is now filed out and champfered off on face, as shown,
iffe face being hollowed out jg" on three or four sides after-
ward to give it a shearing edge. It is now ready for tempering.
As the tempering requires great care it is very necessary to
watch your heat closely, and while making it even, do not
heat any higher than necessary, and plunge it carefully into
cold soft water with one edge down, keeping it in there until
perfectly cold. Now take it out and polish the face and
inside well, and reheat very evenly as before until you observe
327
a dark stra\v color, when you can cool it off, as that is con-
sidered a good temper, and one that will stand wear without
breaking. The punch is pared off on both sides and shank
turned up to size, and then the die is laid on it face to face
and the shape marked out. Now it is shaped off to the lines
and fitted closely in the die, the inside edge of punch being
afterward champfered off as shown. This die can be used in
any press, and is particularly designed ior light metals such
'as zinc, tin, etc. A flat-cutting die would be made by taking
a piece cut from the bar at least i%" longer and
wider than your pattern, and, after planing it, lay
your pattern on and
inside the marks r.n I
Fig. 2.
mark the hole. Then drill around
file out in same wray as you do
the other. The punch would be
made same as last, but without
champfering off the edge. This die
can be used in any press, and is
designed for heavy work, such as
hard brass, steel, etc. Sometimes
there may be some narrow or weak
part in the die which is likely to
break out in time, in which case it is
economical to insert a plug as shown
in Fig. 2. Of course these plugs
can be renewed as often as necessary without disturbing
the form of the die. For round holes of small size, a steel
plug is fitted in a soft steel plate, and the hole drilled and
reamed through it, after which the plug is tempered.
The punch is simply a socket with a set screw in which
round steel of the right size is used, in this way saving any
turn ins: or fitting. Sometimes a gang of punches is used, as
, for which a special punch is designed, In
this, the shank is a separate pieoe,-and
has a dove-tailed groove planed through
it. This groove should be from fa" to
Yt" larger in every way than the dimen-
sions you wish to punch. It should also
have^1," draft, or taper endwise to allow
of a driving bit on the plate fitted in.
This plate should be YZ" thick at least.
You first drill all the holes in your die
in the right position, and after reaming
them our, harden and temper it. You
now place this plate, which you have fitted in the shank, on
the face of the die in its true position and fasten it securely
there. The next thing is to run the drill you used on the
is shown in Fiq
328
die, through tne die holes, and mark their exact position on
this plate. When this is done, remove the die and drill the
holes through from these marks, and countersink them from
behind. Now, the stripper or guide, which should be about
ffi' thick, is fastened on in the position you wish it, and
marked and drilled in the same way. The wire punches are
made by riveting over a head on one end and then driving
them in from the back, afterward filing off any superfluous
metal which extends above the back. When you have made a
gauge and placed it under the stripper, fastening securely, the
die will be finished.
The punches should be filed to an even face, and then hol-
lowed out a little to give more ease in cutting. All the dies
mentioned thus far can be used in any ordinary press. We
will now take up the different kinds of form-
ing dies. There are only two kinds, half-
round and square; all others are modifica-
tions of these-. The depth of a half-round
forming die should be two-thirds of the
diameter to give the best results, and the
punch should go down into the groove as
shown in Fig. 4. A mandril is necessary to
form the work over in the die. A square
or box-forming die is simply a square hole
of the right size, cut through the die, per-
fectly parallel, and with the upper corners
rounded a little. If a smooth flat
bottom is required it is usual to make
the die of thinest steel, and put a plate
under it as in Fig. 5, with a pad and
spring, to throw it out. The punch
is size of the inside of box, and a close
fit. A die for forming a shape at any
angle is simply a groove planed thro'
the block and having a punch to fit
it. Fig. 6 is a view of a common
form of drawing die for deep work.
They are used for making caps, cart-
ridge cases, etc. It consists of a
round disk of steel about ^6 "deep
Fig. 5-
with a hole the size of shell required bored in it .
% This hole is well rounded off at the corner, and counter-
bored from the bottom with a square, sharp shoulder for
stripping the work off the punch after it has passed through
the die. A cast-iron holder with set screw is generally used
with these dies for convenience in- changing. The punch i&
Fig. 6,
329
fitted into a socket in the shank and held by
a set screw. It is rounded on the corners to
give the metal a better chance to turn up
around it. When the punch and die are set
the blank is laid on the die, and the punch
should be tight enough to carry it through
without a wrinkle. If the shell is not long
enough after this operation, make a die a
little smaller and a punch the same, and after
annealing the shells pass them through it. By
repeating this operation you can produce
shells of almost any length. Sometimes it is
necessary to make a die to perform some
operation on the edge of a box which has already been formed
In this case the die is made in such a way that the box can
be put on it, thus placing the die on the
inside. A hub is made the shape of the
box, and with the die dovetailed into its
upper side, a hole being bored clown
through the hub to allow the cuttings to
fall through. v This hub is fitted into a
special holder as shown. The punch is
made in the same way as others. These
dies can be used for any operation that
a flat die performs, such as cutting, form-
ing, etc. As I have given a description
of the different forms of simple dies, I will now explain some
double and combination dies. A double die is two distinct
dies in one plate, and it may be extended to include three
or four, although the work gets complicated in this case,
and the economy is doubtful.
This die may be composed
of two cutting dies, or one cut-
ting and one forming die, or, in
fact, any combination which
may seem desirable. It is gen-
erally used for cutting dies,
such as washers, etc. Fig. 8
shows the plan of one of these
dies designed to make a washer.
You will perceive that the first
punch is the size of the hole in
the washer and the second cuts
out the washer itself. The
punches are set in a long, flat
socket, and fastened with set
screws. The main point in these
Fig. 8.
dies is to get them correctly spaced so as to cut out all the
stock. They can be used in a power or foot press. A.;com-
bination die is one which performs two or more operations in
one die. Fig. 9 is one of these, designed to make a black-
ing-box cover. In this die the pinch comes down and cuts
out the blank which is
immediately gripped be-
tween the two face a
and b, and held firmly
enough to p r e v cut
wrinkling, but still to
allow of its being drawn
through and over the
form which is in the
center of the die.
When tne press is on the
return stroke, the ring b
follows the punch up and '
pushes the cover off
again, while the pad in
the punch does the same
there, thus having the
cover loose on the top
of the die. These dies
Fig- io.
Fig. 9.
must be operated in a power
press, or one specially de-
signed for the purpose, and
they are more conveniently
worked .in an inclined than
a horizontal press, as the
work will then fall off by the
force of its own gravity.
Fig. 10 is a die of the
same class, but with another
operation added. It is de-
signed to make a pepper-box
cover, and perforates four
holes in it after it is drawn.
The punch, as you will per-
ceive, is entirely different in
its construction. -.The die is
the same, excepting that four
cutting holes • or dies are
drilled in the top of the form
331
or plug, and the inside is bored out to allow the cuttings to
fall through. The stub is also bored out for the same reason.
In the punch a is the shank, bored out as shown, b is the
cutting edge or punch proper ; it is bored or chambered out
for the pad c to work in it. d is a plate that screws into the
top of the punch b, to act as a back for the pad c to press
against, and also as a holder for the four small punches. It
has three holes in it, through which short pins work to com-
municate the power of spring E to the pad c. //is a washer
under the spring, and G is a plug or pin that screws in the top
of shank, and extends down to the plate d, against which
it presses, in this way hold- ing the small pin punches down
to place, and guiding and regulating the spring at the same
time. The operation of the die is the same as Fig. 9, only
that after the tin has been drawn down its full length, the
small punches cut the holes through the top, and then the
pad c acts as a stripper for these punches at the same time
as it punches the cap out of the large punch.
As all other combinations are made on this plan, it is
hardly necessary to describe any others.
Fig. 1 1 represents a die for doing the same work, but in
what is called a cam or double-action press. These dies are
much simpler and
cheaper to make and
do equally good work
with the others. The
piece A is the cutting
punch, and works in
the die B. After cut-
ting the blank it
passes down until it
presses the blank
against the face shown
on the inside of the
die. While it is hold-
ing the blank firmly
there the fo r m i n g
cutting punch
yMMMwxvA
I
Fig. 11.
punch C passes down through the _
forces the tin down through the inside die B, in this way
forming it into any shape desired. In passing up again it
strips the box off against the underpart of the die, allowing it
to fall into a box underneath. This covers the list as an-
nounced in the beginning of this article, and although the
different kinds of dies are endless, the foregoing description
will enable the reader to judge of the best way of doing work,
and there is hardly any pattern which cannot be produced by
fme or more of these dies in coiwbination.
332
RULE TO FIND THE STRENGTH OF BOILER
SHELLS AND FLUES.
The pressure for any dimension of boiler can be ascertained
ty the following rule, viz. :
Multiply one-sixtli (^th) of the lowest tensile strength
found stamped on any plate in the cylindrical shell by the
thickness — expressed in inches, or parts of an inch — of the
thinnest plate in the same cylindrical shell, and divided by the
radius or half diameter — also expressed in inches — and the
quotient will be the pressure allowable per square inch of sur-
face for single riveting, to which add twenty per centum for
double riveting.
Boilers built prior to February 28, 1872, shall be deemed
to have a tensile strength of 50,000 pounds to the square inch,
whether stamped or not.
For cylindrical boileryfej- over 16, and less than 40 inches
in diameter, the following formulas shall be used in determin-
ing the pressure allowable.
Let D = diameter of flue in inches.
1760 = A constant.
T = thickness of flue in decimals of an inch.
P = pressure of steam allowable, in pounds.
1760
• = F, a factor.
D
.31 = C, a constant.
FXT
Formula : = P.
C
EXAMPLE,
Given, a flue 20 inches in diameter, and .37 of an inch in
thickness ; what pressure could be allowed by the inspectors?
1760 88X.37
F = = 88 ; then, = 105 + pounds as the allowa-
20. .31 ble pressure.
TO CALCULATE THE SPEED OF A BELT.
To find the speed a belt is traveling per minute, multiply
the diameter infect of either pulley by 3.7 times its revolutions
per minute ; the result is the feet travel of belt per minute if
there is no slip. At the recent " Inventions Exhibition " in
Liverpool, the indicated horse-power transmitted by the belt-
ing averaged, on trial, per one inch width of belt a horse
power, a speed of 200 feet per minute ; it would seem that a
liberal factor of slip should be allowed outside of this.
333
SIZES AND WEIGHT OF SHEET TIN.
Mark.
Xo. of
sheets
in Box.
Dimensions.
Length | Brdth.
Wt.
of
Box.
Inches. Inches. Lbs.
1C 225 ntf 10 112
IIC.
IIIC i2# 9/2
IX 13% 10 140
IXX " " " 161
IXXX " " 182
IXXXX " •" " 203
DC loo 16^ 12% 105
DX ; " " 26
DXX
DXXX
DXXXX....
DC 200 15 ii
DX...
r DXX 210
r DXXX.... « " « 231
? DXXXX... " " 252
jCW 225 13^ 10 112
The following table, showing the number of pounds per
foot in various woods, in different stages of dryness :
Shipping Thoroughly Kiln
Green. dry. air dried, dried.
White ash 4% 4 3/2 24-5
Gray ash 4/2 3^ 3 2l/4
Birch $/2 4/2 4 3/2 '
Basswood 3^ 3 2^ 2^
Cottonwood 3^ 3 2% 2%
Cherry 5 4/2 3/2 3
Chestnut 41A ' 3/2 2H 2%
Soft elm 4 3/2 3
Rock elm 5 4%. 3^ Z1A
Hickory 5^ 4^ 4 31A
Hard maple S/4 4/4 3^ 3
Bird's-eye maple .... 5j^ 4% 3M 3
Curly maple 4$ 4 3/4, 2^
White oak 6 5 4/2 4
Red oak 5^2 4/4 3/4 3
Sycamore 5 4 3 2^
Walnut 6 5 4 3^
Whitewood 4>2 31A 2H 2/^
334
CALIBER AND WEIGHTS OF LEAD PIPES.
CALIBER.
WEIGHT
PER
FOOT.
CALIBER.
WEIGHT
PER
FOOT.
^ in. tubing
LBS.
I
I
2
2
oz.
6
8
12
8
10
12
4
12
s .
\l/2. in. aqueduct. . .
ex. light
LBS. OZ.
3 8
4
i
7 8
3 12
4 8
5 8
6 8
8
3
4
7 8
8
I
n
H
17
5
9
12
16
20
15
18
21
16
21
25
36
8
y% in. aqueduct ....
light
light
medium
strong . .
medium
strong.
ex. strong. . .
J^ in. aqueduct . . . .
ex. light
lio-ht ....
ex. strong. . .
1 34 in. light . . ...
light
medium
medium ....
strong
strong
ex. strong.. . .
2 in. wastf .
ex. stron r . .
j^j in. aqueduct
ex. light
light ...
2
2
3
I
2
2
3
3
i
2
2
I
2
2
3
4
4
2
2
3
3
4
6
12
4
12
8
S
4 i
8
8
8
8
4
12
8
12
12
2 in. ex. light
light
medium
strong
medium
strong
ex. strong. . .
$£ in. aqueduct ....
ex. light.
ex. strong. . .
2 '2 in. 3-16 thick. .
14 thick
5-16 thick. . .
y% thick.
li<rht ..
medium
3 in. waste
strong
3 16 thick...
% thick
ex. strong . . .
fa in. aqueduct ....
ex. light
5-16 thick. . .
y% thick
3 *A in. % thick ....
5-16 thick.. .
y% thick
light .
I in. aqueduct
ex. light
light
4 in. waste
medium.
% thick
strong
5-16 thick. . .
y% thick
ex. strong. . .
lj£ in. aqueduct... .
ex. light
7-16 thick. . .
4^2 in. waste
5 tn. waste ..,.,...
medium
Strong
ex. strong. . .
WEIGHT OF CIRCULAR BOILER HEADS.
Diam.
in
inches.
Thickness of Iron. — Inches.
3-16
X
5-16
H
7-16
X
9-16
16
ii
H
18
21
25
28
32
18
!3
18
22
27
3i
36
40
20
17
22
27 33
33
44
50
22
20
27
33 ! 40
47
54
60
24
24
32
40
47
55
64
7i
26
28
37
46
56
64
75
84
28
32
43
53
65
75
86
97
3°
37
5°
62
74
87
100
112
32
42
56
70
84
99
112
127
34
48
64
79
96
in
128
H3
36
54
7i
89
1 08
125
I42
161
38
60
79
99
120
139
158
179
40
66
88
HO
132
154
I76
198
42
73
97
121
146
170
194 '
220
44
80
107
J33
1 60
187
214
740
46
88
117
H5
176
204
234
^62
48
95
127
158
190
222
254
286
50
103
138
172
206
241
276
310
52
112
149
1 86
224
260
298
335
54
121
160
200
242
28l
320
362
56
I30
172
214
260
302
344
389
58
139
185
231
278
324
370
4i7
60
149
198
247
298
336
396
446
HOW TO CALCULATE THE CAPACITY OF
TANKS.
In circular tanks, every foot of depth, five feet diameter,
gives 4^2 barrels of 31^ gallons each; six feet diameter, 6}£
barrels; seven feet diameter, 9 barrels; eight feet diameter,
12 barrels; nine feet diameter, 15 barrels; ten feet diameter*
18^ barrels. In the case of square tanks, for every foot of
depth 5 feet by 5 feet gives 6 barre.s ; 6 by 6 feet, 8 ] < bar-
rels; 7 by 7 feet, n)4 barrels; 8 by 8 feet, I ~ T^ barrels ; 9
by 9 feet, 19^ barrels; 10 by lo feet, 23 -V barrel.
NUMBER OK BOILER KIVKTS IN A 100 POUND
KEG.
Length.
/^
Inch.
9-16
Inch.
H
Inch.
11-16
Inch.
;X
Inch.
7/8
Inch.
990
760
56;
450
H
875
725
530
415
X
800
690
490
389
356
228
H
760
650
460
370
329
211
'/2
730
625
425
357
290
i So
1%
710
595
505
340
271
174
i%
690
550
39°
325
264
169
1%
665
530
375
312
257
165
2
630
5io
360
297
248
156
2l/S
590
500
354
289
237
152
2%
555
490
347
280
232
149
2l/2
525
475
335
260
219
141
*%
500
440
312
242
211
133
3
460
AID
290
224
203
127
3X
430
380
267
212
I9O
US
3%
410
350
248
2O I
1 80
108
zH
395
335
241
I92
l62
102
4
326
230
184
158
99
4>4
312
220
177
150
96
4^
298
2IO
171
146
94
4#
284
2OO
166
138
89
5
270
190
161
135
87
SX
256
1 80
156
130
84
5^
244
172
*5i
124
80
5^
233
164
H5
I 2O
77
6
223
157
140
"5
74
6#
213
150
137
in
71
6
207
146
134
107
69
6
203
H3
129
104
67
7
i)8
I4O
125
100
64
To BRONZE IRON CASTINGS.— After having thoroughly
cleaned the castings, immerse them in a solution of sulphate
of copper. The castings will then take on a coaHng of cop-
per. Then wash thoroughly in water.
Copper is said to lose 18 per cent, of its tenacity upon
being raised from 60° to 36o9.
337
NUMBER OK " AMERICAN" " NAILS AND CUT
SPIKES IN A POUND.
.s ^
g
bi>
<u
0
e
CJ
fcJD
.S
'cL
g J5
.'2
5
G
r<v
rt
S
'S
£
^:
u
£
U
2 F
1050
1/g
3 1'
860
2
900
jif
3
500
650
670
4
300
480
45°
500
3^
5
212
350
300
370
2
6
160
85
240
212
260
2X
7
135
65
190
1 60
210
2/^>
8
95
50
135
120
155
234:
9
75
40
3
10
60
35
"5
IOO
135
16
3X
12
48
30
IOO
120
16
34
25
80
IOO
H
4'r
20
24
20
65
85
12
30
18
50
70
IO
5r
40
15
40
60
9
50
12
8
6 2
»y
60
10
6
|
4
Clinch-nails weigh about the same as common.
Box-nails are made ^ inch shorter than common nails of
same sizes.
5 Ibs. of 4d or 3^ Ibs. of 3d will lay i,oop shingles. 5^
Ibs. of 3d fine will put on 1,000 laths, four nails to the lath.
Bricks made from the refuse of slate quarries are stronger
than stone; they stand 7,200 Ibs. compression against 6,000
for stone, and 3,200 Ibs. for common brick. The cost is from
$12 to $20 per thousand.
In London 20,000 men earn their living at carpenter work*
4,000 in Paris, and 4,000 in Berlin. Hours in London are
per week.
33*
WAXING FLOORS.
Take a pound of the best beeswax, cut it up into very small
pieces, and let it thoroughly dissolve in three pints of turpen-
tine, stirring occasionally if necessary. The mixture should
be only a trifle thicker than the clear turpentine. Apply it
with a ~ag to the surface of the floor, which should be smooth
and perfectly clean. This is the difficult part of the work,
for, if you put on either too much or too little, a good polish
will be impossible. The right amount varies, less being
required for hard, close-grained wood, and more if the wood
is soft and open-grained. Even professional "waxers"are
sometimes obliged to experiment, and novices should always
try a square^foot or two first. Put on what you think will be
enough, and leave the place untouched and unsteppecl on for
twenty-four hours, or longer if needful. When it is thor-
oughly dry, rub it with a hard brush until it shines. If it
polishes well, repeat the process over the entire floor. If it
does not, remove the wax with fins sandpaper and try again,
using more or less than before, as may be necessary, and con-
tinuing your experimenting until you secure the desired result.
If the mixture is slow in drying, add a little of any of the
common "dryers" sold by paint dealers, japan for instance,
in the proportion of one part of the drier to six parts of tur-
pentine. When the floor is a large one, you may agreeably
vary the tedious work of polishing by strapping a brush to
each foot and skating over it.
HOW TO MAKE AN IVORY GLOSS ON WOOD.
A most attractive ivory gloss is now imparted to wood
surfaces by means of a simple process with varnish, the latter
being of two kinds, namely, one a solution of colorless resin
in turpentine, the other in alcohol. Eor the first, the purest
copal is taken, while for the second sixteen parts of sandarac
are dissolved in sufficient strong alcohol, to which are added
three parts of camphor, and finally, when all these are dis-
solved, they are combined with five parts of well-shaken
Venice turpentine. In order to insure the color remaining
a pure white,, particular care is essential that the oil be not
mixed with the white paint previously put on. The be>t
French zinc paint, mixed with turpentine, is employee), an 1,
when d,y, this is rubbed down with sandpaper, following
which the varnish described is applied
339
CARE OK OAK LUMBER.
Throughout the civilized world, except in extremely hot
fountries, one or more species of the oak is found. In this
country oak forests abound in almost all the Southern and
Cerrtral States. In species there are so many that even
experienced lumbermen are frequently perplexed to correctly
designate to which class a sample piece of wood belongs.
Ordinarily in the yard trade but two kinds are known —
white and red. Among shipbuilders, carriage-makers and
machinists may be found live oak, a species of wood that is
peculiarly adapted to purposes where immense strength is
necessary. The average lumberman, when he talks about
white oak or red oak, is influenced solely by the color of the
wood when it becomes partially seasoned. Again and again
veterans in the wood-working business have been known to
select red oak for white, and vice versa in fact, from a
dozen specimens of six different species of oak, they have
been unable to correctly name a single sample. f
Oak is a wood • which calls for unusual and unceasing
care .in its manufacture. The tendency of oak, from the
moment an ax is planted in the side of the tree, is to split,
crack, and play all sorts of mean tricks on the owner. Such
tendencies can be held in hand, and almost absolutely
Dbviated, by following certain rules. A thick coat of water-
woof paint applied to the ends of the logs is a wise expendi-
wre ; it prevents the absorption of moisture. Oak, when
piled, should have the ends protected so as to prevent absorp
tion of rain and moisture, followed by the baking process of
a hot sun Alternate moisture and heat is the prime cause
of checks and cracks, and when such defects begin in oak
they are bound to increase and ruin otherwise perfect stock.
Oak should be stuck as fast as sawed. It is a mistake to
permit it to lie in a dead pile even for a single day. It is a
wood that contains a large amount of acid, which oozes to the
surface as fast as the lumber is sawed, and, if the stock is
allowed to remain piled solid, it is apt, even in a few hours,
to cause stain on the surface. The lumber should be stuck
in piles not over six feet* in width. The bottom course
should be raised two feet from the ground, and a space of five
mches left between the pieces. It is advisable to follow this
rule up to about the fifth course, when tne space can be
gradually diminished to two inches, and continued to the top
of the pile! In this way air has free circulation through the
pile, and the lumber will dry readily. The pile should ca»t
toward the back, so that rain will fallow the inclination.
340
Board sticks not over three inches wide should be used,
the front stick placed so as to project a half inch beyond the
lumber. This plan permits moisture to gather in the stick,
not the lumber. Other sticks should be placed not over four
feet apart, and in building the pile the sticks should be
exactly over one another. By this plan, warps, twists and
sags are avoided.
Jt is advisable to pile every length by itself. This rule
permits more systematic piling, and, in shipping, consign-
ments can be made of lengths precisely as wanted. Thick-
nesses in piling should never be mixed. Twisted stock is
certain to be the result if this advice is ignored.
The sap should be placed downward. The draft is up-
ward, and any practical lumberman can readily observe trie
advantage of this advice. Every pile should be well covered
with sound culls, the covering so placed as to project beyond
all sides of the pile. Raise it a foot from the top course.
The piles should not be nearer than twenty inches apart;
twenty-four inches is better.
HOW TO SHARPEN A PLANE-IP ON.
The simple art of sharpening a plane-iron is supposed to
be understood by every mechanic, remarks a writer in a
contemporary, but there are hundreds of men who cannot do
a creditable job in this respect. The common tendency is to
round off the edge of the tool until it gets so stunted that
under a part of the cutting the tool strikes the work back of
the cutting edge. To do the job correctly we will begin at
the beginning, and grind the tool properly. First, the kind
of wood to be cut must be taken into consideration. Com-
mon white pine can best be worked with a very thin tool,
ground down even t > an angle of 30 degrees, provided the
make of the tool will allo ,v it. Some planes will not, for the
iron stards .so " stunt," or nearly perpendicular, that its grind-
ing causes a severe scraping action, which soon wears away the
tool. In such cases, from 45 to 60 degrees is the proper
angle for plane-iror»~ and this, too, is about :ight for hard-
wood planing. . 3) .
Determine the angle you want on the plane-iron and then
grind to that angle, taking care to grind one flat bevel, and
not work up a dozen facets. If the stone be small, say 12 to
18 inches in diameter, the bevel will be slightly concave
like the side of a razor, and this is a quality highly prized by
many good workmen. In grinding, take care to avoid a
"feather edge." If the tool already possesses the right
341
•hape, grind carefully right up to this edge, but not grinding
it entirely off. The time to stop grinding a tool is just before
the old bevel is ground off.
Should the tool need any change of shape, such as the
grinding out of a nick or a broken place, then put the edge
of the tool against the stone and bring the tool to the de-
sired shape before touching the bevel.
Let the iron lay perfectly flat upon the stone, with a
tendency only to bear harder upon the edge of the bevel
than upon the heel. Move the iron back and forth on the
stone as fast as your skill will allow, taking care that the
heel of the bevel is not lifted from the stone. As you be-
come proficient in whetting an iron, the heel may be lifted
from the stone about the thickness of a sheet of paper, or
just enough to prevent it from touching. The reason why
many carpenters cannot set an edge is because they raise
their hand too much, and perhaps rock the tool, thus forming
a rounding bevel, the sure mark of a poor edge-setter. ^
The proper way to oil-stone a tool is to continue the
grinding by rubbing on the oil-stone until the bevel left by
the grindstone is entirely moved and the edge keen and
sharp. If this be properly done the tool need not be touched
upon its face to the stone, but among a dozen good edge-
setters not more than one can do it. It is a delicate opera-
tion, anil can only be acquired by long practice. Nine times
out of ten the average workman is obliged to turn the plane-
iron over and wet the face thereof, and here is where many
men fail who have done the other things well. By raising the
back of the tool only a very little the edge is "dubbed off,"
and regrinding of the face becomes an immediate necessity.
A good stone should " set " an edge on a tool wh» jh will shave
off the hair on a person's wrist without cutting the skin or
missing a single hair.
VALUE OF MAHOGANY.
As is known to every woodworker, mahogany has no
equal for durability, brilliancy, and intrinsic value for any
Work which requires nicety of detail and elegance of finish.
Cherry, which is a pretty wood for effect, and extremely
•leasing when first finished, soon grows dull and grimy-
looking. Oak, which has been so much used of late, is
attractive when first finished, but experience teaches that it
does not take many months to change all this, and instead of
alight, fresh looking interior, one that has a dusty appear-
ance is presented, which no amount of scraping ana re-
caking will restore to its original beauty. What applies to
in this yet more applicable to ash.
Mahogany, however, seems to thrive best under the condi-
tions which are detrimental to these other woods. At first
of a light tone, it grows deeper and more beautiful in color
with age, and although its first cost is more than these other
woods, yet its price is much less than is popularly supposed ;
#1 1 the only objection urged against it has been cost. What
is more valuable, however, and what makes mahogany in
leality a less costly wood, is the fact that, unlike cherry, oak
f»r ash, it is easily cleaned, because it is impervious to dust or
jb'rt, while it does not show wear, and instead of growing
duller, grows brighter and more pleasing in appearance.
While first cost is more than that of cherry, oak or ash, it is
nevertheless true that the judgment of many men has led
tfiem to regard mahogany as the cheaper wood when its dura-
bility and cleanly qualities are considered, and to-day it takes
front rank in first-class material.
POLISHING GRANITE.
The form is given to the stone by the hands of skilled
aiasons in much the same way as is done with other stone of
ihfter nature. Of course, the time required is considerably
greater in the case of granite as compared with other stones.
If the surface is not to be polished, but only fine-axed, as it
is called, that is done by the use of a hammer composed of a
number of slips of steel of about a sixteenth of an inch thick,
which are tightly bound together, the edges being placed on
the same plane. With this tool the workman smooths the
surface of the stone by a series of taps or blows given at a
right angle to the surface operated upon. By this means
the marks of the blows as given obliquely on the surface of
the stone are obliterated, and a smooth face produced.
Polishing is performed by rubbing, in the first place, with
an iron tool and with sand and water. Emery is next
applied, then putty with flannel. All plain surface and
molding can be done by machinery, but all carvings, or sur-
faces broken into small portions of various elevations, are
done by the hands of the patient hand-polishers.
The operation of sawing a block of granite into slabs for
panels, tables or chimney-pieces is a very slow process, the
rate of progress being about half an inch per day of ten hours.
The machines employed are few and simple; they are tech-
nically called lathes, wagons and pendulums or rubbers. The
fethes are employed for the polishing of columns, the wagons
343
for flat surfaces, and the pendulums for molding^and such flat
work as is not suitable for the wagon. In the lathe fhe
column is placed and supported at each end by points upon
which it revolves. On the upper surface of the column there
are laid pieces of iron segments of the circumference of the
column. The weight of these pieces of iron lying upon the
column, and the constant supply of the lathe-attendant of
sand and water, emery or putty, according to the state of
finish to which the column lias been brought, constitute the
m whole operation. While sand is used during the rougher
" state of the process these irons are bare, but when using emery
and putty, the surface of the iron next to the stone is covered
with thick flannel.
The wagon is a carriage running upon rails, in which the
pieces of stone to be polished are fixed, having uppermost the
surface to be operated upon. Above this surface there are
shafts plated perpendicularly, on the lower end of which are
fixed rings of iron. These rings rest upon the stone, and
when the shaft revolves they rub the surface of the stone. At
the ^aiiie time the wagon travels backward and forward
upon the rails, so as to expose the whole surface of the stone
to the action of the rings. The pendulum is a frame hung
upon hinges from the roof of the workshop. To this frame
are attached iron rods, moving in a Horizontal direction. ^In
the line upon which these rods move, and under them, the
stone is firmly placed upon the floor. Pieces' of iron are then
loosely attached to the rods, and allowed to rest upon the sur-
face of the stone. When the whole is set in motion, these
irons are dragged backward and forward over the surface of
the stone, and so it is polished. When polishing plain sur-
faces, such as the needle of an obelisk, the pieces of iron are
flat ; but when we have to polish a molding, we make an
extra pattern of its form, and the irons are cast from that
pattern.
IN FAVOR OF SMALL TIMBER.
The statement that a 12x12 inch beam, built up of 2x12
planks spiked together, is stronger than a 12x12 inch solid tim-
ber, will strike anovice as exceedingly absurd. An authority
on the subject says every millwright and carpenter knows that it
is so, whether he ever tested it by actual experience or not.
The inexperienced will fail to see why a timber will be
stronger simply because the adjacent vertical longitudinal
portions of the wood have been separated by a saw,, and if
this were th: only thing about it, it would not be stronger,
344
but the old principle that a chain is no stronger that its
weakest link comes into consideration. Most timbers have
knots in them, or are sawed at an angle to the grain, so that
they will split diagonally under a comparatively light load.
In a built-up timber no large knots can weaken the beam
except so much of it as is composed of one plank, and planks
whose grain runs diagonally will be strengthened by the
other pieces spiked to them.
VALUABLE ARTESfAN WELLS.
Two artesian wells recently sunk in Sonoma Valley,
Cal., are considered to be worth not less than $10.000 each.
One of them flows 90,000 gallons of water per day, and the
other 100,000.
The cement by which many stone buildings in Paris have
been renovated is likely to prove useful in preparing the
foundations for machinery. The powder which forms the
basis of the cement is composed of two parts of oxide of
zinc, two of crushed limestone and one of pulverized grit,
together with a certain proportion of ochre, as a coloring
agent- The liquid with which this powder 'is to be mixed
consists of a saturated solution of six parts of zinc in com-
mercial muriatic acid, to which is added one part of sal-ammo-
niac. This solution is diluted with two-thirds of its volume
of water. A mixture of one pound of the powder to two
and a half pints of the liquid forms a cement which hardens
quickly, and is of great strength.
Large cylinders of window-glass are now cut by encircling
the cylinder with a fine wire, which is then heated to redness
by an electric current, and a drop of water being allowed to
fall upon the hot glass a perfectly clean cut is obtained.
The old method was to draw out a fiber of white-hot semi-
molten glass from the furnace by means cf tongs, and to
wrap it round the cylinder.
The Hudson Bay Company, which was incorporated 225
years ago, is the oldest incorporated company.
The grindstone quarries along the shores of the Bay of
Fundy are developed when the tide is down. The best ma-
terial is down low in the bay.
Some fine pearls were recently discovered in Tyrone (Ire-
land) rivets.
345
WOODEN BEAMS.
Safe Load. Uniformly Distributed, for Rectan-
gular "White or Yellow Pine Beams one inch
thick,
allowing 1,200 Ibs. per square inch fibre strain.
To obtain the safe load for any thickness, multiply the
safe load given in table by the thickness of beam.
To obtain the required thickness for any load, divide
by the safe load for i inch given in table.
i*
DEPTH OF BEAM.
6"
7"
8"
9"
10"
11"
12"
13"
14"
16"
16"
r«t
Ib,
IbT
Lbs.
Lbe.
LbL
Lbs.
Lbs.
Lbs.
Tfc.
Lbs.
Lbs.
t£
960
1810
1710
2160
2670
3230
3840
4510
5230
6000
6830
6
800
1090 i 1420
180012220
2690
8200
3760
4860
5000
5690
7
690
930
1220
1540
1900
2300
2740
3220
8730
4290
4880
8
600
820
1070
1850
1670
2020
2400
2820
8270
8750
4270
9
530
730
950
1200
1480
1790
2130
2500
2900
3330
8790
10
480
650
850
1080
1880
1610
1920
2250
2610
3000
3410
11
440
590
780
960
1210 i 1470
1750 2050
2380
&730
3100
12
400
540
710
900
1110
1340
1600 1830
2180
2500
2840
18
870
500
660
830
1030
1240
1480 i 1730
£010
2310
2630
14
840
470
610
770
950
1150
1870
1610
1870
2140
2440
15
820
440
570
780
890
r6so
1280
1500
1740
2000
2280
16
300
410
530
680
830
1010
1200
1410
1630
1880
2130
17
280 880
500
640
780
950
1130
1330
1540
1760
2010
18
270 860
470
600
740
900
1070)1250
1450
1670
1900
19
250 840
450
570
700
850 1 1010
1190
1380
1580
1800
20
240 1 830
430
540
670
810
960
1180
1810
1500
1710
21
2801 810
410
510
630
770
910
1070
1240
1430
1630
22
220
300
890
490
610
730
870
1020
1190
isec
1550
23
210
280
870
470
580
700
830
98011140
1300
1480
24
200
270
360
450
560
670
800
940
1090
1250
1420
25
190
260
340
430
530
650
770
900
1050
1200
1370
26
180
250
830
420
510
620
740
870
1010
1150
1310
27
180
240
820
400
500
600
710
830
970
lliC
1260
28
170
230
800
890
480-
580
690
800
930
1070
1220
29
170
230
290
870
460
560
660
780
900
1030
1180
WEIGHT OF
/
A CUBIC FOOT OF SUBSTANCE.
Iverag*
NAMES OF SUBSTANCES. V«*ht
• Lit
Anthracite}' solid, of Pennsylvania, • • 93
'•' broken, loose, - » * • 64
" • " moderately shaken, • . • 68
" heaped bushel, loose, - « „* • (80)
Ash, American white, dry, ? . »/ » • • - 38
Asphaltum, - - • f; *.<••• • • 87
Brass, (Copper and Zinc,) castj •» » .» • - 604
" rolled, - - . ,* * *• * " 624
Brick, best pressed,' • »• • « •» • 16O
" common hard, - - ... * - 126
" soft, inferior, - - • « • - - 100
Brickwork, pressed brick, - •. - - - 140
" ordinary, - - -112
Cement, hydraulic, ground, loose, American, Rosendale, 56
", «' " " H Louisville, 6O
" " " " English, Portland, - 90
Qherry, dry, - - - - - ' .- • • 42
Chestnut, dry, - - - - • - - 41
Coal, bituminous, solid, - - - - • -84
«' " broken, loose, - - - . 49
«« " heaped bushel, loose, • - • (74)
Coke, loose, of good coal, 27
" " heaped bushel, .- (3£>l
Copper, cast, - ^ - - . - 642
rolled, 648
Earth, common loam, dry, loose, - ' - - - 78
" " " moderately rammed, 95
" as a soft flowing mud, • «• 108
^bony, dry,. ..,.». 70
EJm, dry, .,_..». 36
Flint, ^ - • « « 102
Class, common window, • » £ 167
347
WEIGHT OF SUBSTANCE.
(CONTINUED.)
Average
NAMES OF SUBSTANCES. . w««ht
Ite
Gneiss, common. ....... [QQ
Gold, cast, pure, or 24 carat. - ... . 1204
" pure, hammered, - - . . . . 1217
Granite, --.....„ ^70
Grave!, about the same as sand, winch see
Hemlock, dry, . - ..... 25
Hickory, dry, - 53
Hornblende, black, -.-..,. 203
Ice, - . . - . 58.7
Iron, cast. ......... 450
wrought, purest, .-..-„ 485
average, 480
Ivory, 114
Lead, 711
Lignum Vitx, dry, 83
Lime, quick, ground, loose, or in small lumps, - «• 53
thoroughly shaken, - 75
" " " " per struck bushel, - - (881
Limestones and Marbles, ...... 188
" " loose, in irregular fragments, - 96
Mahogany, Spanish, dry, - - - - - " 53
Honduras, dry, - ..... 35
Maple, dry, .-.-..-. 49
Marbles, see Limestones.
Masonry, of granite or limestone, well dressed, - 185
" mortar rubble, - - *••/:- - 154
" dry •• (well scabbled,) - - 138
•• sandstone, well dressed, - - - - 144
Mercury, at 32° Fahrenheit, 849
Mica, 183
Mortar, hardened, 103
Mud, dry, close. -; . . . • 80 to 110
wet, fluid, maximum; - - 120
Oak, live, dry, ......... £9
"WEIGHT OF SUBSTANCES.
(CONTINUED.)
NAMES OF SUBSTANCES. Weight
Oak, white, dry, ...«**. 62
" other kinds, - - - * * • 32 to 45
Petroleum, -.-•.*.- ^55
Pine, white, dry, - • » • » * - 25
" yellow, Northern, - - - « » ? 34
" " Southern, - - • * * - 45
Plarinum, - - - - - » 9 - 1342
Quartz, common, pure, - . . . » . 165
Rosin, - - - £"- - » « + * 69
Salt, coarse, Syracuse, N. Y. - .» - * - 45
" Liverpool, fine, for table use,\ .-» * • *. 49
Sand, of pure quartz, dry, loose, - - - 9Q to 106
" well shaken, - . - , .« 99 to 117
" perfectly wet, - - - * - 120 to 140
Sandstones, fit for building, * • 151
Shaies, red /or black, - - - - - . 162
Silver, - - - - - - - „•- 655
Slate, - - - -..^- . • . . 175
Snow, freshly fallen, - - - - 5 to 12
" moistened and compacted by rain, - .- 15 to 5O
Spruce, dry, -• - - . -'+*'- 25
Steel. - - - »-„.»,* . 490
Sulphur, -.. - •- ».* - 125
Sycamore, dry, ;-• - - - - »- • -X87
Tar, - - . - - - - - . . . 62
Tin, cast, -n- - - - - *',*-. 459
Turf or Peai, dry, unpressed, - - «... 20 to 30
Walnut, black, dry, , . - . -.-'-.,- 38>'
Water, pure rain or distilled, at 60° Fahrenheit, , 62#
" sea, - - -.- .-. -64
Wax, bees, . - , . . - - - 6O.5
Zinc or Spelter, v ........ 437
Green timbers usually weigh from one-fifth to one-half more
than dry.
349
ROUND CAST IRON COLUMNS. — Safe Load in Tons of
2, ooo pounds; safety, 6. — These tables are based on
columns made of the best iron, perfectly molded and
with both ends turned.
M
Ovtlide Diameter. 8 in.
4
m
Ontsl.le Diameter, 4 IB".
'3
36 in.
X »n.
1 in.
•
•i
*/2 in'-
H in.
lin.
3
44,070
69,890
71,190
4
61,020
85,880
106,220
4
*9,8frl
53,535
63,686
6
56,1 40
79.202
98,02(1
i
84,579
46,992
55,859
6
51,246
72,124
KD.81I6
6
30,23 I
4 1 ,083
48.835
7
46,652
65,968
82,035
7
26,268
35,698
42.433
s
41,868
58,912
72,865
8
22,812
81,001
36,851
9
37,912
53,303
65,926
9
19,844
26,967
32,056
10
33,885
47,690
58,985
10
17,889
28,564
28,010
11
80,701
42,681
53.01 1
It
1.6,147
20,694
24,630
12
27,476
38.671
47,880
1*
1 3,402
18,213
21,650
13
2 0.0410
34,794
43,167
13
11,786
16,123
19,228
14
22.464
31,616
39,104
14
10,469
14,335
17,097
15
20,5 1 1
28,667
36,504
15
9,463
'12,847
15,271
16
18,557
26,1 18
32,304
Ootiide Diameter, 6 in.
Outside Diameter, <5 in.
&in.
fc in.
lin.
fcin.
lin.
IK i".
6
79,104)
141,250
118,000
6
140,120
177,410
210,180
6
74,118
13 2 ,3 5 3
105,838
7
132,782
168,1*20
199,174
7
68,996
123,207
98,566
8
125,253
168,587
187,880
8
63,886
114,082
91,266
9
117,676
148,993
176,514
9
68,951
105,270
84,216
10
109,945
139,205
164,908
10
64,261
96,895
77,516
11
108,021
130.438
1A4,;>»2
11
49,876
89,062
71,250
1 2
96,119
121,7011
144,179
12
45,826
81,832
65,466
13
89,6I2i 113,448 134.403
in
42,105
75,187
60,150
14
83,514 105,739 125.371
14
S8,710
69.125
55.300
15
77,810; 98,517
1 1 6,7 1 5
15
85,618
63,603
60,833
16
72,532i 91,835
108,798
16
32,830
58,625
46,900
1 7
67,633 8 ;),<; 3 2
101,449
17
30,298
54,103
43,283
18
63.094 79,886
94.64'.'
.18
28,003.' 50.006
40,005
19
58,9621 74.653!' 8S.44:!
19
25,931! 16,306
37,045
20
55.13I! 69,S03
82,697
20'
24,056
42,957
34.366
21
5l,5S4j 65,818
7 7,:J7»>
22
48,348
•; i ,2 1 5
72,523
1
23
45,365
»7,4«H
68.048
0«Mi<U Diameter, 7 i.
Outfttde Diameter, 8 iu.
Kin.
1 in.
\14 in.
fc in.
1 in.
l!'i ni.
7
166,110
212,440
255,880
8
193,230
•2 4 S, 600
•299,4 r.O
M
158,664
202.917
243,938
9
185,671
•2:{8.H;<; 287.7:$;
9
151,086
193,226
232,282
10
177,942
•_'2S.93%J: 27."»,7.">9
10
148.288
183,375
220,440
11
170.110
2 IS. 85 61 263.628
11
135,769
173,636
208,783
12
162,279
L'OS,;sO 251,48.*
12
128,198
163.954
197,094
18
154.359
P.»S.688 23S»",26H
IS
120,936
154,667
185.930
14
146,700
I8S.7SSI 2t»7,34:{
14
119,948
145,730
175,186
1 5
l:{»,6r»:>
1 79,674' 216.42:*
15
107,824
137,258
165,002
16
ue.5ri'j
170,535: 205.417
10
101,062
129.250
1 55, 3 7:,
17
1 •.',•>,; S I 16 1.832 194.93I
17
95,123
121.654
146,244
IS | 119.328 15:5.516 1X4.917
18
89,567
114,548
137,701
19 n:i.i5o 145,574 i7;>,3.-><»
Itt
84,275
107,780
12 9. 5 65
20 ' I07.3O2
I3S.050! 166,487
30
79,380
101.520
122.040
21 ! 101.796
130.966
i:,7,7.,4
21
74,798
9&,660j 11 4, 995
22 96,580
124.256
149.672
22
23
70,589
664686
90,277 108,525
85,i20! I08,4."»S
28
24
9 1.6.'. li
'S7.O01I
1 17,920
1 1 1.942
1 1-2.040
i:s 4. *::•.•
554
62.980
8<M83 U6.750
8 a
82.695
I06.X92 liS.l.il
R£)UND CAST IRON COLUMNS— (Continued).
-
OdUlde DiEtoeler, ) 5 In.
J3
tf.
e
•1
Outside Diameter, 16 In.
lin
1& in.
vita..
lj£to,
2 in.
2% in.
16
496,974
718,798
922.884
16
772,129
993.6481,198.139
16
17
486,723
496,261
708,972 903.058
688,838| 884.518
17
18
767. US
741,095
974. 785J1, 175,918
955.158!l,161,830
18
460,664
673,5661 804.910
19
726,521
986,397jl. 127.523
19
20
21
464,978
444,242
483,467
658,045 844,980
642,525i 825,050
626,940 805.038
20
21
2 2
711,0421 916,3I2il,103,34ft
695.3911 895.149[l.079,067
879.610! 871. 750:i.054,674
22
422,78f
611,419
785.108
28
604.031! 854. 7»6J1, 080,400
23
412,903
595,898
76i,178
2 I
048.452 88 4.7401 1.006,22 5
24
401,405
580.568
745.45)3
25
632.9 U
814.773
982,156
25
890,938
565,425)
726,054
26
617,567
794,962
95 8. '29!*
26
880,651
550.417
706,777
27
802,329' 775,367
984,057
27
870,401
635,733
687,900
28
587,806; 756,016
011.828
2H
860.241
621,220
669,28(5
29
572.537 737.017
888.365
29
850,565
607,035
651.071
80
o57,988
718,281
865,841
30
840,933
403.105
633.1 S3
31
543.702 699.918
843,681
81
880.921
470.49-2
615,704
8-2
529.69*! 681.866
822,845
82
822,329
466.198
595,633
33
515,060
664,180
800,633
Outside Diameter, 17 In.
On JeUe Diameter, 17 In.
IHin.
2 in.* 1 2y2in..
1)6 in.
2 in.
Wz in.
17
825,852
,065.025, 1/280,84 4
26
(J80.50;;
885.856
1,070,353
1'8
S09,752
,045,798'l.2G8.<H2
27
671,01b
865,875
1.046,216
19
795,883
,026. 19$!U24 0.089
28
655,758
846.176
1.023,415
20
779,994
.000,495 1. 216.125
20
640,031
825.6G7
998,841
21
764,510
986.515 1.101.982
30
625.661
807,846
975,496
22
748,952
906. 43!) 1.167.726
81
(510.007
788,807
952,492
23
788,832
946.270 1.1 43, 355
32
& 96.4 Go
769,645
929.944
24
317.618
22a.oo<; im,87i
33
582.132
744,267
903,737
25
702,060
905, 981i 1.09 4. 01 5
34
560.206
730.626
888.7W8
NEW STEEL RAILS USED AS LINTELS OR GIRDERS.
Safe load In tons or 2000 )bs.
A
Length
f
I
2
1 8
_L
5.50
5 05
5
3.50
4.00
7 8
i)
2:50!
2.70 ,
i
62 Ib. rail,
60 Jb. rail,
per
ycr
yardjlO.76
yard 12.
7.00
8.00
•n n\n
47u
3. J 2.76
«.r>o; a.
TWiHrwil i
in i
. !n
i > t \
n (i? .\ (i IIOA
n i •>. •. n i 9Ain 09 R.
A OrtA '
0 .170jO.226jO.SOO i
tin H 1 15
«<>| I.50J 1.40;
1 SOJ 1 .70 1 00"J
- j
AREAS OF CIRCLES,
Advancing by Eighths.
' .0
n
'«
rf*
>ij
.9*
• K
•«
i.
.0
.0122
.0490
.1104
. 1963
.3068
.441!
.6019
.7854
.9940
1.227
1.484
1.767
2.073
2.405
2.701
3/14 1C
3.546
3.976
4.430
4.908
5.411
5.939
6.4»1
?.0€8
7.669
8.295
8.946
9.621
10.32
11.04
11.79
12.56
13.36
14. 18
15.03
ir,.90
16.80
17.72
13.06
19 63
20.62
21.64'
22.69
23,. 7 5
24.85
25.96
27.10
28.27
29.46
30.67
31.91
33.18
34.47
85.78
37.12
38.48
39.87
41.28
42. 7i
44.17
45.66
47.17
48 70-
50.26
51.84
53.45
55 . 08
5G.74
58-42
60. J3
6 1 . 86
€3.61
78.54
65. 39
80.51
67. 20
82.51
69 . 0-
84.54
86.59
88.66
90.76
92. 8S
95.03
97.20
99.40
101 6
103.8
106.1
108.4
110.7
113,0
115.4
117.8
120.2
122.7
125.1
127.6
130.1
132.7
135.2
137.8
140.5
143.1
145.8
148.4
151.2
153.9
15G.6
159.4
162.2
165 1
lf.7.9
170.8
173.7
17«.7
179.6
182.6
185.6
168.6
191.7
194.8
197. a
201.0
204.2
207.3
210 5
213.8
217.0
220.3
223.6
226.9
230 3
23J.7
237.1
240.5
243.9
247.4
250.9
254.4
258.0
261.5
265.1
268. 8
272 .'4
276.1
279.8
283.5
287.2
29 i . 0
294.8
298 . 6
302.4
306.3
310.2
314.1
318. 1
322.0
326 . 0
330 0
334.1
338.1
342.2
< ] C
t
346 3
350 4
354.6
358 8
363 . 0
367.2
371.5
375 8
380.1
884 4
388.8
393.2
397 6
402 . 0
406.4
410. 9
452.3
457 1
461 .8
466 6
471.4
476.2
481. I
485.9
530.9
536.0
541.1
5(52.0
567.2
572.5
615.7
577.8
62 1.2
583.2
626 . 7
632.3
637 9
64 3. 5
649.1
654.8
660.5
666.2
671.9
677.7
683 . 4
689.2
695.1
700.9
706.8
712.7
718.6
724.6
730.6
736.6
742-6
748.6
754.8
760.9
767-0
773.1
779.3
785.5
791.7
798.0
804.3
810.6
816.9
823.2
829.6
836.0
842.4
818.8
855.3
861.8
368.3
874.9
881.4
888.0
894.6
901.3
907.9
914.7
921.3
928 . 1
934.8
941.6
948.4
955 . 3
9(52. 1
969.0
975.9
982.8
989 8
996.8
1003.8
'.010.8
1017.9
1025.0
1032.1
1039.2
046.8
053.5
1 Ot>0.7
1068.0
1075.2
1082.5
1089.8
1097. 1
104.5
111.8
Iii9. 2*
1126.7
1134.1
1141.6
1149.1
1156.6
164.2
171.7
1179.3
1186.9
1194.6
1202.3
1210.0
1217.7
225.4
233.2
1241.0
1248.8
1256. ff»
1264.5
1272.4
1280.3
288.2
296.2
1304.2
1312.3
320. &
1328.8
1336.4
1344.5
352.7
360.8
1369.0
1377.2
385.4
1393.7
1402.0
1410.3
418.6
427.0
1435.4
1443.8
452.2
1460.7
1469.1
1477.6
486.2
494.7
1503.3
1511.9
520.5
1529.2
1537.9
546.6
,r>55.3
564 . 0
1372.8
581.6
590.4
1 599 . 3
1608.2
617.0
626.0
634 . 9
1643.9
1652.9
352
CIRCUMFERENCES OF CIRCLES.
Advancing by Eighths
CIRCUMFERENCES.
' .0
.*
.,
t«
-H
.*
.H
•H
.0
-892-7
.7894
1.178
1.570
1.963
2.356
2.748
8.141
8.5S4
8.927
4.319
4.712
5. 105
5.497
5.890
6.288
6.675
7.0«8
7.461
7.854
8.246
8.639
9.032
9.424
9.817
10.21
10.60
10.99
11.38
11.78
12.17
12. 56
12.95
13.85
18. M
14.13
14.52
14.92
1J5.31
15.70
16.10
16.49
16. 8ft
17.27
17.67
18.06
is. ir>
18.84
19.24
19.68
20.02
20.42
?O.Rl
21.20
2 J . 5»
21.99
22.38
22.77
23.16
23 56
23.95
24 . 34
21 71
25.18
25.52
25.9
26.31
^t, . 70
27.0-.I
J7.48
27. NH
28.27
28.66
29.05
29.45
SS. 84
SO. 2 3
,-Mf.sa
31.02
81.41
81.80
32.20
32.59
32.. 18
33.37 '*
.3:3.77
34. IK
84.55
84.95
85.34
85.<?3
86.1?
36.52
SO. 91
37.3ft
37.69
88.09
38.48
88.87
39.27
39.66
40.05
40.44
40.84
41.28
41.62
42.01
42.41
42.80
43.19
43.98
44.37
44.76
45.16
45.55
45.94
46.33
46^73
47.12
47.51
47.90
48.30
48.69
49.08
49.48
49.87.
50.26
50.65
51.05
51.44
51.83
52.22
52.62
53.01
53.40
58.79
54.19
54 . 58
54.97
55.37
55.76
5f%. 15
56.54
56.94
57.33
57.72
58 - 1 1
58.51
58.90
59.29
59.69
60.08
60.47
60.86
61.26
6 1 . 65
62.04
62 .*3
62.83
63.22
63.61
64.01
64.40
64 79_
65.18
65.58
65.97
66.86
66'. 75
67.15
67.54
67.93
68.82
68.72
69.11
69.50
69.90
70.29
70.68
71.07
71.47
71.86
72.25
72.64
73.04
73.43
73.82
74.22
74-61
75.00
75.39
75.79
76.18
76.57
76-96
77.86
77.75
78.14
78.54
78.93
79.32
79.71
80.10
80.50
80.89
81.28
81.68
82.07
82.46
82.85
83.25
83.64 '
84.03
84.43
84.82
85.21
85.60
86.00
86.39
86.78
87.17
87.57
87.98
88.35
88 . 75
89.14
89.53
89.92
90.32
90.71
91.10
91.49
81.89
92.28
92.67
93.06
93.46
93.85
94.24
94.64
95.03
95.42
95.81
96.21
96.60
96.99.
97.89
97.78
98.17
98.57
98.96
99.35
99.75
100.14
100.53
100.92
101.32
101.71
102.10
102.49
102.89
103.29
103. 67
104.07
104.46
I 04 . 85
105.24
105.64
106.03
106.42
106.81
107.21
107.60
107.99
108.39
108.78
109. 17
109.56
109.96
110.35
110.74
111.18
111.53
111.92
112.31
112.7%
118.10
118.49
113.88
114.28
114.67
115.06
115 45
115.85
116.24
116.68
117.02
117.42
117.81
118.20
118.61
118.99
119.38
119.77
120.17
120.56
120.95
121.34
121.74
122.13
122.52
122.92
128.31
123.70
124.09
124 49
124.88
125.27
125.66^
126.06
116.45
126.84
127.24
127.63
128-02
128.41
128.81
129.20
127.5
129.98
180.88
130.77
IS i. ift
1.55
181.95
132.34
132.7
133. 13
133.52
133.91
134.30
i3i . 70
135.09.
135.48
135.8
136.27
136.66
137.05
137.45
137.84'
138.29
138.62
139.0
139.41
139.80
140 19
140.59
140.98
Ml. 37
141.76
142.1
142.55
142.94
143.34
143.73
144.12
353
Weight of Cast Iron Columns Per Lineal Foot
Foot of Plain Shaft.
:a
THICKNESS OF METAL.
I
Kin.
Xln.j^m.
Mini
*
n
lin
lifcin.
IK in.
iy2m.
MK
2 tii
2
4.3
6 5
6.0
7 8
7 4
9 8
8 4 9.2 9 7
11 5 12 9 14 0
ul:.::
3
3H
6.8
8 0
9 7
11 5
12 3
14 7
146
17 6
16.6
20.3
18 3
22 6
«? ::::.
4
9.2
13 3
17 .2
20.7
23.9
2f
.8 29.5 ..
10.4
15 2
19 6
23.81
27 e
31 1 34 4! 37.3
39'^
6
11.7
17.0! 22 1
26.9!
31 3
3c
4
39 .1
42 ?
46 fl
12.9
18 9 24 5
29.9'
35 0
&
.7 44 2
48,3
52.:.
6
14.1
20.7 27.8 33 0
as -
44 0
49 1
53.9
58.3
6V$
15 3
22 .6
29 51 36 1
42 3
48 '6
54 0
69 4
64.4
' r.
16 6
24 4 31 9
39 1
46 C
52
.6
58 fl
64 9
70.6
81 0
17 8j 26 2; 34 4
49 7
Bf
.9 63 f
7U.4
7fi 7
88 4:. -
t'-' '
8
19 Ol 28 1 36 8
45 3
53 4
61
68 ',
75 9 82 8i 95 7! .
20.2
29 9! 39 3
4* 3>
57 1
65 ft
73 e
HI 5
89 0 HM. 1; .-.
0
21 5
31 8 41 7
51 4
60 8
69 8
78 S
87 0
w i 110.5!. ...
9H
22 7
33 6, 44.2
54 5j
64 4
74
1
K< 5
92 5
101 I
117.8
J:jy.2'
10
23 9
35 4! 46 8
5- 5
OS 1
7S 4
88 4 08 0
107 4 125.2
HI :
ir.7 r
11
25.2 37 3 49 1
26 4' 39.1 51 6
60 6:
63 7'
71 R
,-,,
fe,
87 0
93 3! 103 f>
98 Si 109 1
119 7
132 5
139 9
150 3, 1«A «»
158 9; 17« T
27 6 4J 0. 54 8
66 7
7y 2
91
3
Iff* 1. 114 6
125 8 147 3l
167 &, 18C .5
I
}
12
28 8 42 8' 56 5
69 K
82 6
95
*?
108 0 120 1
131 9! 15*: 6
176 l! 196 3
44 fl1 58 9
72 9,
865
ww 9
112 9
126 6
m i
162.0
184 7
20«5 2
13
46 5 61 4
759
90 2
104
2
117 R 131.2
U4 2 169 4 103 Ji 216 t>
13/4
63 8
663
79 0
m \>m r,
97 e!l!2 8
!£.' 7
136 7
142 2
151J 3 176 71 201 9j 2L'u i1
15*5.5! 1^4 l! 210 ,V 235 6
44Vi
' 68.7
85 2.1
01 2
117
0:1.12 .-,i 147 7
102 6i iyi 4
219 I
246 *
15
. _ •' ... 71 2
88.2104 9
121
3
137 A! \rS, '2
168 7
108 8
*»7 6
.255 5
16
7fi 1
94 3il
V :5
HJU7 3 1»U .<
!<"*! (V 213 i)\ 244 ^
274 \t
i:
81 0
86 9
100 5:119 71138
106 6127 Oil47
1
157 1
166.0
175 ;}
1S6 4
1M8 3j 228 3 ml 0
24Ja 6 243 0 279 2
.294 5
314 1
u
90 8
112 8il34 4
155
7
170 7! 197 4
217 8
257 7 296 4
S« 8
ft
"."..i .. 95 7
118 9; 141 '.
164
.3 IWJ.5J.208 5
230
274 4 313 5
Sfvl 4
INCREASE IN WEJUE
T fOrt
y-i IN I NCR* AS E IN DIAMETER
*•«.
*».
*m
ft in
HM,
»
m.
l,n I
Sg in, l
,,,,
1 I
fcm. Uiin 2 in.
•7
1 S
2.5
3 i
37
4
T-
77 \
6 1
74
86 [.».»
354
Weight of Square or Rectangular Cast Iron Col*
umn Shafts Per Lineal Foot.
EXAMPLE : Column 6" X 10" X i7 + 10' o'. 6" X
jo" = 1 6" X 2 = 32. Following out line on which 32 is
found in left hand column to column headed i", we find
the weight per foot to be 87.5 pounds, which, multiplied
by 10' i" = 875 pounds.
jftul
i -? 24
M ETAL
*••
V
23.8
28.7
84.2
1"
w-
IX"
"»"
HT
2"
14
<16
18.6
22.5
26.4
21.1
25.8
30.5
25.0
31.3
87.6
26.4
38.4
40.4
27.3
35.1
43.0
28.1
87.5
46.9
49.2
60.0
M
80.8
86.2
89.7
48.8
47.4
50.8
56.3
60.2
•2.6
20
34.2
39.8
45.1
60.0
64.6
68.6
65.6
71.1
76.0
22
f4
26
88.1
42.0
45.9
44.6
49.2
53.9
50.6
56.1
61.5
66.3
62 6
68.8
61.5 66.4
68.51 74.2
7 ft. 6] 82.0
75.0
84.4
93.8
82.0
93.0
103.9
87.6
100.0
112.5
28
49.8
68.6
67.0
76.0
82.6
89.8
103.7
114.8
125.O
90
53.7
63.8
72.6
81.8
89.6
97.7
112.5
126.8
192.6
12
57.6
68.0
77.9
87.6
96.7
105.5
121.9
187.7
150.0
94
61.5
72.7
83.4
93.8
108.7
118.3
131.3
147.7
162.5
86
65.4
77.3
88.9
100.0
110.7
121.1
140.C
158.6
175.O
88
69.8
82.0
94.8
106.3
117.8
128.9
150.0
169.5
187.5
40
73.2
86.7
99.8
112.6
124.8
136.7
159.4
180.5
200.0
42
77.1
91.4
105.3
118.8
131.8
144.6
168.8
191.4
212.6
44
81.0
96.1
110.8
126.0
138.8
152.3
178.1
S02.3
225.O
46
84.9
100.8
116.2
131.3
145.9
160.2
187.5
213.8
2S7.6
48
60
88.8
92.8
105.5
110.2
121.7
127.2
137.6
143.8
152.9
159.9
168.0
175.8
196.9
206.3
224.2
235.2
250.0
262.6
62
96.7
114.8
132.6
150.0
167.0
183.6
215.6
246.3
275.0
64
100.6
119.5
138.1
156.3
174.0141.4
226.0
257.0
287.6
66
104.5
124.2
148.6
162.6
181.0199.2
234.4
268.0
300.0
68
108.4
128.9
149.0
168.8
188.1 207.0
243.8
278.9
312.5
60
112.3
133.6
154.5
175.0196.1 214.9
253.2
289.8
825.0
62
116.2
138.3
160.0
181.3 202.1 222.7
262.5
800.8
387.5
64
120.1
143.0
165.4
187.5209.2230.6
271.9
811.7
350.0
68
124.0
127.9
147.7
162.3
170.9
176.4
193.81216.2
200.o!223.2
238.3
246.1
281.3
290.6
822.7
336.6
362.6
875.0
70
131.8
157.0
181.8120613 230.3 253.9
300.0
344.5
S87.5
;2
135.7
161.7
187.7 212.5287.3261.7
309.4
865.5
400.0
74
139.5
166,4
192.8 218.81244.3 269.5
818.8
366.4
412.6
76
78
143.5
147.4
171.1
175.8
198.3
203.7
226.0J261.8
23I.3J268.4
277.3
285.2
328.1
337.6
877.3
383.3
425.0
487.5
80
151.3
1 &0.5
20».2
237.6265.4'293.0
340.9 399.2
450.0
355
CUBIC MEASURE.
1. £ 0005788
1*728. 1.
46656- 27.
Tard.
.000002144
.03704
J.
Oubir Metre*
.000016386
.028315
764513
A CUBIC FOOT IS EQUAL TO
1728 cubic inches
.037037 cubic yard
803564 U S struck bushe)
of 2150 42 cub in
U S pecks
U. S liquid gallons
of 231 cub in.
$.42851 U. S dry gallons of
268 8025 cub in
321426
7.48052
29 92208 U. S liquid quarts.
25.71405 U S dry quarts
59 84416 U S liquid pints
51 42809 U 8. dry pints.
239.37662 U. S. gills
.26667 flour barrel of 3
struck bushels
23748 U 8. liquid barrel
of 31 >£ gallons
\
A cubic inch of water at 62? Fahr weighs 252 458 grains.
A cubic foot of water ai 02 Fahr weighs 1002. 7 ounces.
A cubic yard of water at 62' Fahr. weighs 1692 pounds
FRECNH CUBIC OR SOLID MEASURE.
Pint
Quart.
Buah.
Cubic Inch.
Cu Ft
Centilitre •
Decilitre . •
Litre j
Dry . .
Liquid
Dry .
Liquid
Dry ..
Liquid
Dry ..
Liquid
Dry .
Liquid
Dry
Liquid
Dry
Liquid
.0181
.0211
.1816
.2113
1.816
2.113
2i 13
211 3
•
J 61016
6.1016
61.016
610.16
6101 6
(51016.
.0353
.3531
3.531
35.31
353.1
0908
1056
908
1.056
908
1056
90.8
1056
10565
10565.
2837
Decalitre •
Hectolitre . •
Kilolitre OT A
Cubic Metre /
MyrioWtre
2.837
28.37
283.7
AVOIRDUPOIS WEIGHT.
The standard avoirdupois pound is the weight of 27.7015
cubic inches of distilled water, weighed in the air, at 39.83
degrees Fahr., barometer at thirty inches.
Ounces.
Pounds.
Quarters.
Cwt8.
Ton.
1.
= .0625 ==
.00223 =
.000558 =
.000028
16.
1.
.0357
.00893
.000447
448.
28.
I.
.25
.0125
1792.
112.
4.
1.
.05
35840.
2240.
80.
20.
A drachm — 27.343 grains.
A stone — 14 pounds.
A quintal ~ 100 kilogrammes.
7000 grains = 1 avoir, pound =
5760 grains = 1 feroy pound —
Kilos p. sq. ceiitim. x 14.22 =
Pounds p. sq. inch x .0703 —
1.21528 troy pounds,
.82285 avoir, pound.
Pounds p. sq. inch.
Kilos p. sq. centiui.
FRENCH WEIGHTS.
EQUIVALENT TO AVOIRDUPOIS.
Gnic*
<>,„,,.
Pounds,
Milligramme
Centigramme
Decigramme
.0154&
1543SI
1.54031
* J352
003527
.000023
.0002^
G ram ine
15.4831
.035275
.00220*
Decagramme. . . .
Hectogramme
Kilogramme .
M vrio*rvammc
154.883
1543.31
15433.1
352758
3.52758
35.2758
352.758
.022047
220473
2.20473
22.0473
Quintal
3527 58
220.473
Millicr or T«Mmt»
35275.8
2204 73
357
SQUARE MEASURE.
Inches Feet- VnnJ Perches. Acre.
1. = .00694 = 000772 -- .0000255 = .0000001 5&
144. 1. .111 .00367 .000023
1296. 9. 1- .0331 .0002066
39204. 272*. 30*. 1. .00625
6272640. 43560. 4840- 160 1
100 square feet = 1 square.
10 square chains - I acre.
1 chain wide =• 8 acres per mile.
I hectare = 2471143 acres.
S= 27.878.400 square feet.
= 3.097.600 square yards."
= 640 acres.
Acres x 0015625 = square milei
Square yard x 000000323= square miles
Acres x 4840= square yards
Square yards x 0002066 = acres.
A section of land is 1 mile square, and contains 640 acres.
A square acre is 208 71 ft at each side; or, ; 20 x 198 ft.
A square * acre is 147 58 ft at each side. or. 110 x 198 ft.
A square * acre is 104 355 ft. at each side, or. 55 x 198 ft.
A circular acre is 235 504 ft in diameter
A circular 4- acre is 166 527 ft. in diameter
A circular ± acre is 117.752 ft m diameter
FRENCH SQUARE MEASURE.
Square
Q
Q
Millimetre.
00154
0000107
000001
Centimetre
15498
0010763
.000119
Decimetre
15 498
107630*5
011956
Met or Ccn
1549 8
10 76305
1 19589
Decametre
154988
1076 305
119.589
Hectare ..
107630 58
1195H 95
Kilometre .
'.38607 amis
10763058
1195895.
Mynamei.
38.607
• ..,'.. -
35*
SURVEYING MEASURE.
(LINEAL.)
Inch**.
Feet.
Yard*.
Chains.
1.
= .0888
= .0278
= .00126
12.
1.
.333
.01515
36.
3.
1.
.04545
792.
66.
22.
1.
63360. 5280.
1760.
80.
Mile.
.000015$
.000189
.000568
.0125
1.
One knot or geographical mile = 6086.07 feet - 1855.11
metres =1.1526 statute mile.
One admiralty knot = 1.1515 statute miles = 6080 feet
LONG MEASURE.
Inehe*. Feet. Yard*. Poles. Furl. Mlie.
1. = .083 = .02778 = .005 = .000126 = .0000158
12. 1. .333 .0606 .00151 .0001894
36. 3. 1. .182 .00454 .000563
198. 16f 5*. 1. .025 .003125
7920. 660.
220.
63360. 5280. 1760.
A palm = 3 inches.
A span = 9 inches.
40.
320,
1.
8.
.125
1.
A hand — 4 inches.
A cable's length — 120 fathoms.
FRENCH LONG MEASURE.
luches.
Feet.
Yards.
MIk-8.
Millimetre
03937
0033
Centimetre
!393G8
.0328
Decimetre
3 9368
.3280
.10036
Metre
39.368
3.2807
1 09357
Decametre
Hectometre
303.68
32.807
328 07
10 9357
100 357
Oo2l;>4
Kilometre
3280 7
1093 57
t>2mo
Myriametre
32807.
!00:V, 7
; -.H.vtn6
359
STRENGTH OF MATERIALS,
ULTIMATE RESISTANCE TO TENSION
W LBS. PER SQUARE INCH.
METALS.
Atertf*.
Brass, cast, 18000
" *>re, ....... 49000
Bronze or ^un metal, 36000
Copper, cast. - - . 19000
sheet, 30000
bolts, . . 36000
w>re, - - ^ - 60000
Iron. casi. 13400 to 29000, - ... 16500
" wrought, round or square bars of 1 to 2 inch
diameter, double refined, - 6OOOO to 54OOO
•• wrought, specimens j£ inch square, rut from large
bars of double refined iron, . 60000 to 53OOO
" wrought, double refined, m large bars of about
7 square inches section, - - 46OOO to 470OO
wrought, plates, angles and other shapes, 48OOO to 61OOO
plates over 36' ' wide. - 46000 to 6OOOO
Wrought iron, suitable for the tension members of bridges,
should be double* refined, and show a permanent elongation of
20 per cmr .n ft", when broker* m small specimens, and a re-
duction o» -irea of 26 per cent at point of fracture
The modulus of elasticii) of Union Iron Mills' double refined
bar .ron »s 25000000 tu 2,6000000, from tests mado on firushed
eyebars
iron, wire. 70000 to 10000O
1 wire-ropes. - • *> - 9000O
Lead, sheet, ....-.-. 3300
Steel, ...... 65000 to 12000O
Tin, cast, - 460O
Zjnc, - - ' - - - - * - 700O to 8000
STRENGTH OF MATERIALS.
(CONTINUED.)
TIMBER, SEASONED, AMD OTHER ORGANIC FIBE&
Ash, English, » „ ...-.- . . 17QOO
« American, - - . - - 11000 to 14000
Beech, " - 1500O to 1800O
Box, - - - w * • \ ~ - - 20000
Cedar of Lebanon, - -. * - - - 11400
" American, red, - • * - - / - 1O3OO
Fir or Spruce, - 1000O to 1380O
Hempen Ropes, - - - - - 12000 to 16000
Hickory, American, - - - - 12800 to 18000
Mahogany, 8000 to 218OO
Oak, American, white, - - - - «- - 18OOO
" European, - -, - - - 10000 to 19800
Hne, American, white, red and pitch, Memel, Riga, - 10000
long leaf yellow, - 120OO to 19200
Poplar, - - - ' . . , ~ . . 7000
Silk fiber, ..---,.. 52000
Walnut, black, .,.-«.. 16OOO
STOKE, NATURAL AND ARTIFICIAL.
Brick and Cement, ------ 28O to 300
Glass, - - ; - -, - . - r - - 9400
Slate, ...-,- r 9600 to 12800
Mortar, ordinary, 50
ULTIMATE RESISTANCE TO COMPRESSION,
METALS.
Brass, cast, - « * * - - - - 103OO
Iron, « . * . * a . 82000 to 14500O
" wrought, * • • < 3600O to 4OOOO
Ifc K.
STRENGTH OF MATERIALS.
(CONTINUED.)
TIMBER, SEASONED, COMPRESSED IN THE
DIRECTION OF THE GRAIN
Average.
Ash, American, - 4400 to 5800
Beech, - - 5800 to 6900
Box, - 10300
Cedar of Lebanon, - - 5900
" American, red, 6000
Deal, red, - -• 6500
Fir or Spruce, 5100 to 6800
Oak, American, white, - 7200 to 9100
" British, 10000
" Dantzig, - - 7700
Pine, American, white, - 5000 to 5600
" long leaf, yellow - - 8000
Spruce or Fir, 5800 to 6900
Walnut, black, - - 7500
STONE, NATURAL OR ARTIFICIAL.
Brick, weak,
" strong,
" fire, -
Brickwork, ordinary, in cement,
. " best,
Chalk,
Granite,
lyimestone,
Sandstone, ordinary,
550 to 800
1100
1700
300 to 450
1000
330
5500 to 11000
4000 to 11000
4000
ULTIMATE RESISTANCE TO SHEARING
METALS.
Iron, cast, -
" wrought, along the fiber,
TIMBER, ALONG THE GRAIN.
27700
45000
White Pine, Spruce, Hemlock,
Yellow Pine, long leaf,
Oak, European,
Ash, American,
500 to 800
- 630 to 960
2300
- 2000
362
/"able of Safety Load of Cast Iron Columns— Factor of Safety 10,
This factor of safety of 10 has been adopted to allow for imper-
fections in casting; such as air-holes, unequal thickness of metal,
•tc., devietion of pressure from axis of columns, and the effect of
latenal forces accidentally applied. Where these risks do not
occur, a factor of 6 may be taken for safe load. Ends of columns
should always be turned- true.
(•q4#ua| .jo jooj
jad eutur.ip3
jo -em ui iqS|o&
55 i! 31522 55253 s:-!^! :B
saqooi
at va&B iBuouoag.
91
•* « CO :c » ® l> ^ »% i^ X X t- 9*O7SM>e» •* »
f
kl
UI
u
M
1
c
|
: : : : : : : : : : : '. : ::::::**
it
ot
1
M : : ! '; 1 N 28
2
J
: : '. : :''.'.:
LENGTH OF'COLUMNS l*i
BOTH EWDB TUBWRD. •£
91
94
|
:] \ i ;=sss :sssasa ss
g
a!
COC r^ 91 A
at
s
fi
OC99 US PS
£' j
rcc ^i- r.
_«„„ ^,-919191 9191WSCW* MM
-
1
S2 £* 2«^CtM OS^^Ot^ A^XM^X C.M
'
94
1
r-o ee r.
^ -^atOM 919J««» «»^»00 **
O
1
22 2, 2,Sxg g5g.5 S!.3S58 5g
OK.
(P
I
«2 2a» »^-wto -«-e9. ,9«.x*o« «e»
I
.*? "§
«< i i? » * «9«et>91r> «MX«9 »• 3t W M 3t « O *
15 91 9J»8« •* « 10 W X »
bi~ . . u . -
; »» *w «*_j **-..; *x^s** xs
TABLE OF SAFETY LOAD OF CAST IRON
COLUMNS.
(CONTINUED.)
•tuihiai jo jooj
^^ ^ ----- --r . 1
en foju iBnouooc
^LENGTH OF COLUMNS IN FEET.
|» | BOTH ENDS TURNED.
e
ee
£_
I
r-3tciec «?-•:« -•*««- -wo Cii.c-r»es.o Oso*
s
-,s,^. -*».^ ^ «^^wo ^ -,cr®^ *xe*
s
Jr
a
$
<N(M9»eBeo«-* .aieseesewe so-r^.e.*®.- ^-ao
Ot
M
•1
,
e
i
^^^^ 9t „ ^ & ~
•-
1
' CODfM^O «. «1 *• » -«~, ^T«cr
^^^^.ooo ^.-h^..^c,t- .e^.-.-Qc-c- ec-oe
CO
1
^-..o^^coo Vke.e««^«> CD^^XSS*. -*a
»
I'
£
I
i(5 *« i- •?» GC «r d O r» » »1 CC ift OS Si OC t^ iffl 8C OS t~ SI 91 "Si
— _Z^!!I — —
0
1
SS^££§ S;3S«SS^ SSI22I5S SSS:
00
I
— OD i» *i SS ® S3 M « 91 — 5: r- » MS»O«®«®» "r<~
'«
1
"Itfjajv
364
TABLE OF SAFETY LOAD OF CAST IRON
COLUMNS.
(CONTINUED.)
* -qiJBuai JO JOOJ
' a ad s u tun [03
EET.
NGTH- OF COLUMNS
BOTH ENDS TURNED
J±_
H^
corsxorco
'•*! O <X t •• » «O
5 OS CO **• «- -* — OS «ff «1 3S r- — CO O
C » (5« r- CC 5: — — — X O «R « — US CC 99 88 O — O 3> r» S
sssccai r>I — csd-r — oJ o'»oo-^cct»«o •^ot^oree*
-CCOSO CSl-QCOSO«-<iN I-XOSC— (M •*• OS O — <N CO •*
waoor- ««J-o^,«- o^09*,Or^r~OD»0-0
OOUOOr^ i- Ct- O5 O — »» CO gjc OS O « W "t- «O OS O «-• 1C -»• CD
»^09 oOOSOi-i»»99kO OSOi-i&4e««Sr- O — w-^fior.
c«-«o
O»t*ke t^osi^ogio**** O«OS»OCDOS« ocDoo»-4«e»
»ie9»or- Of-ieo^n:
~OMCOCCG>1CO GC M r- 01 CO «
df 1-1 <N ^*« U3 CC QC •- Oie9>C
Crushing and Tensile Strength, in Ibs., per square inch jf Natural
and Artificial Stones.
DESCRIPTION.
Weight
per
Cubic ft
tn Ibs
Crushing Force.
Lbs. per Square
Inch.
Aberdeen Blue Graaite .. ..'..
16?
8.400 to 10.914
Quincy Granite
160
15 300
Freeetone, Belleville . . .
3 522
Freestone, Caen . .
1 088
Freestone, Connecticut.
3 319
Sandstone, Acqula Creek, used for Capitol Wash-
ington
5,340
Limestone, Magnestan, Graf ton. Ill
Marble, Hastings, N. Y
17.000
13,941
Marble, Italian
12,624
Marble, Stockbrldge, City Hall, N. Y .
Marble, Statuary
10,382
3,216
Marble, Veined
165
9 681
Slate
9,300
Brick, Red ^ T
135.5
SOS
Brick, Pale Bed
130.3
562
Brick, Common
800 to t 000
Brick, Machine Pressed
6 222 to 14 214
Brick Stock
2,1^7
Brtck-work, set In Cement, bricks not very hard,
Brick, Masonry, Commou
521
500 to 809
Cement Portland
1,000 to 8 309
Cement, Portland, Cement i. Band 1
Cement Roman
1,280
342
Mortar
120 to 240
Crown Gl&M . ; ....
31 000
Portland Cement .. .
TENSION.
427 to 711
Portland Cement wHb Sand
92 to 284
Glass Plate
9 420
Mortar
50
Plaster of Paris . ..
72
6lme .-
11,000
Capacity of Cylindrical Cisterns.'
FOR EACH FOOT OF DEPTH.
Diameter
In Feet.
Gallons.
Pounds.
Diameter
In feet.
Gallons.
Pound*,
2.0
2.5
23.5
36.7
1M
306
9.0
9.5
475.9
530.2
4,421
3.0
52.9
441
10.0
587.5
4,899
3.5
72.0
600
11.0
710.9
5,928
4.0
94.0
784
12.0
846.0
7,054
4.5
119.0
992
13.0
992.9
' 8,280
5.0
146.9
1,225
14.0
1,151.5
9,602
5.5
177.7
1,482
15.0
. 1,821.9
11,023
6.0
211.5
1,764
20.0
2,350. 1
19\596
6.5(
248.2
2070
25.0
8.G72.0
30,820
7.0
287.9
2,401
30.0
5,287.7
44,093
7.5
S30.5
2.756
35.0
7,197.1
60,016
8.0
376.0
3,185
40.0
9,400.3
78,? as
8.5
424.5
3,540
366
PROPERTIES OF TIMBER.
• • I i ! j I \ I 8 n
' : i : : • : ; 2 S
i: i ! I Mi!
s | s s
i -' I §
3 :
S :
2 2
5 3
f* ~ g
222
strength
reftklng.
e = 100.
III
§ 3 s ? * 2 ' S 8 5j i ? =
222§2S222222|3 =
CMO«rt S 0?S???!r)>O «$
rushing
gth per eq
.. In lt>6.
| S §
232
s § S
o §
i I i
£ l
3222
I i. i s
2 2 S 5
| | | |
d c«* a of
P «»
M M
i
S 2 S
000
s 5 i
-»
5 3 S
: I U j i I i I I* *
j>g i Iv I i ••>.-' 3>. " »J «;:' J
I- 1 :» I 1 I * i . * - 1 4l I *
dowan.SsooSa:^^
367
SQUARE CAST IRON COLUMNS.
Safe Load in Pounds. Safety 6.
BOTH ENDS TURNED.
f
} 4utfllde*5Ue Column, 8x8.
LengtL. [|
Outride SizeColBM, I Ox It/
• &in..;
I in.
l&in.
XHL
lin.
Ifein
8
255,486
328,902
458,113
10
325,965
422,874
599,07 1
247,656
318,822
444,073
11
318,015
412,560
684,4**
10
289,457
308,266
429,370
12
309,751
401,839
66»,*7t
231,786
298,430
416,670
13
301,232
390,787
563,61*
12.
222,400
286,308
898,787
14
292,540
379,512
687.««*
1 is
213,752
275,176
888,280
15
283,752
368.111
521, 7*0 '
14
204,896
263,774
267,399
16
274,925
356,669
505,**? t
15
196,642
258,153
252,606
17
266,109
346,229
4H9,07o
16
188,268
242,368
337,584
18
257,362
833,876
472,980
17
180,126
231,887
322,986
19
248;709
822,660
457,087
18
172,220
221,709
808.810
20
240,204
311.616
441,46ft
19
164,589
211,884
295,125
21
231.878
300,809
426,14*
20
157,242
202^,426
281,950
22
223,720
290.282
411,16*
21
150,225
193,354
269,314
23
216,881
280,062
896,754
*2
148,452
184,674
257,224
24
208,083
269,946
382,42f
23
137,014
176,37(i
245,562
25
200,619
260,263
368,704'
£4
180,881
168,490
284,682
26
193,398
250,895
355,434
25
126,849
160,809
223,985
27
186,411
241,830
342,59*
OatBlde Site Column, 12x12.
Outside Site Column, 12x12.
l.in.
l&in.
2 in.
1 in.
iKta.
2 IQ. V
12
616,846
740,029
989,720
21
414,986
594,184
7.>4,52<t
13
606.383
725,048
980,696
28
403.458
577,678
7 38,560
14
495,550
709,537
901,000
23
392,093
561,406
712,890
15
'484,418
693,598
880,765
94
380,864
545,328
692,480
46
473,057
677,382
860,104
25
369.829
529,527
•4)72,416
17
461,579
660,888
839,160
26
359.005J 514.030
652,730
18
449,913
644,194
818,024
27
348.401: 498.847
683,460
10
438,253
627,409
796,824
2ft
337.7311 483.569
614,056
L£
426,693
610,804
775.684
29
3 29,941 j 469.552
690.S**
COST OF LIVING IN CHINA.
Land in China is divided into more holdings than anjr
other land in the world. It takes but a very small piece •£
land to support a Chinese family. The Chinese are the
closest and most thorough cultivators in the world. Field
hands in China are paid $12 per annum. The food is
cooked by the employer. With his food he is furnished
straw, shoes and free shaving — the last a matter which a
Chinaman never neglects for any great length of time where
it is possible to secure the luxury. It costs about $4 a year
to clothe a Chinaman. Much of the land ki China is divided
Up into gardens of areas as small as one-sixth of an acre.
; NOTES OX HOT WATER SYSTEMS.
Let your " risers " not be less than i%", for smaller pipes
soon become coated, if the water used contains lime or otner
matters in solution or suspension.
; Galvanized pipe is best; it does not become rusty and dis-
color the water.'
In ordinary pip? be sure to get " galvanized steam," and
Hot " galvanized gas. "
Let your draw-off services be for bath i", to lavatories
l", for hot water ]£'. Do not make the " draw-offs " too
small, it takes too long to drain a pipe of cold water.
. The larger tire pip?s the freer the circulation, and, if you
have Hard water, they will remain in good order longer.
; Be sure that all joints are secure and free from leaks, and
always look through a pipe before fitting it in place, to see
that there is no dirt or impediment to the flow of water
through it.
Avoid the use of elbows in circulating pipes, use only
bends; if you cannot avoid using an elbow, see that it is a
round one.
TO SOLDER ALUMINUM.
M. Bourbouze has formed an alloy of 45 parts of tin and
55 parts of aluminum, which answers for soldering aluminum.
This alloy possesses almost the same lightness as the pure
aluminum, and can be easily soldered. M. Bourbouze has
invented another containing only ten per cent, of tin. This
second alloy, which can replace aluminum in all its applica-
tions, can be soldered to tin, while it preserves all the prin-
cipal qualities of the pure metal.
A new and curious alloy is produced by placing in a clean
crucible an ounce of copper and an ounce of antimony, and
fusing them by a strong heat. The compound will be hard,
and of a beautiful violet hue. This alloy has not yet beea
applied to any useful purpose, but its excellent qualities,
independent of its color, entitle it to consideration.
A CHEAP FILTER.
A cheap filter which any tinner can make is 12x6 inches ia
size, and 8 inches high. The water flows in near the top, and
»n the top is a door through which to get into it to clean H.
The outlet pipe at the bottom projects two inches up on the
inside to hold the dirt back. A large sponge is placed inside,
which forms the filtering medium, which, of course, can be
cleaned as often as desired.
COMPOSITION OF BABBITT METAL.
Genuine Babbitt metal, according to the formula of the
inventor, is 9 of tin, i of copper. Antimony has been added
since, so that the proportions by hundreds will stand 80 tin,
5 copper, 15 antimony. For high speeds the metals should
be cooler, giving a larger proportion of tin ; for weight the
metal should be harder, giving a larger proportion of
antimony.
THE HEATING SURFACE OF A STEAM RADIA-
TOR.
For instance, the radiator contains 300 feet of one-inca
pipe; what will be its heating surface in square feet? A.
300 feet =3, 600 inches. The outside circumference of one-
inch pipe=4 inches. And 3,600 X 4 = 14,400 square inches
of heating surface. Lastly,
14,400
= 100
144
square feet of heating surface. The way you have calculated
the heating surface is not correct, because you did not multi-
ply the length of the pipe by the circumference.
A CHIMNEY THAT WILL DRAW.
To build a chimney that will draw forever, and not fill up
with soot, you must build it large enough, sixteen inches
square; use good brick, mid clay instead of lime up to the
comb; plaster it inside with clay mixed with salt ; for chimney
tops use the very best of brick, wet them and lay them in
cement mortar. The chimney should not be1 built tight to
beams and rafters; there is where the cracks in your chimney
comes, and where most of the fires originate, as the chimney
sometimes get red hot. A chimney built from the cellar up
is better and less dangerous than one hung on the wall,
ANCIENT USE OF LEAD.
The ancients, like the moderns, used lead to fasten iron
into stone, to give a glaze to pottery, and as a help to the
manufacture of glass. Very singular were the " imprecation
tablets, surreptitiously deposited in tombs, and sometimes
even in the coffin of the deceased, that a curse might follow
him to the other world, '^ which seem "to have been more
frequently deposited by women than by men." Vitruvius
describes elaborately a vast aqueduct, the lead >n which
would cost to-day two millions. The leaden bullets of the
ancient slingers often bore an inscription in relief such as
4i Appear," " Show yourself," " Desist," " Take this," " Strike
Rome." The Greeks were especially fond of bullets with
such mottoes, and they have been found upon Marathon and
many other famous fields.
A RUSSIAN WELDING PROCESS.
The process of welding, invented by Mr. Be Benardox, of
Russia, is now applied industrially by the Society for the
Electrical Working of Metals. The pieces to be welded are
placed upon a cast-iron plate supported by an insulated table,
and connected with the negative pole of a source of electricity.
The positive pole communicates with an electric carbon in-
serted in an insulating handle. On drawing the point of the
carbon along the edges of the metal to be welded, the oper-
ator closes the circuit. He has then merely to raise '.lie point
slightly to produce a voltaic arc, whose high V jperature
melts the two pieces of metal and causes them to unite. The
intensity of the current naturally varies with the \\ork to be
done.** For regulating it, a battery of accumulators is used,
and the number of the latter is increased or diminished as
need be. This process of welding is largely employed in the
manufacture of metallic tanks and reservoirs.
COLD SOLDER.
LaMetallurgie gives the following receipt for cold solder:
Precipitate copper in a state of fine division from a solution
of sulphate of copper by the aid of metallic zinc. Twenty
or thirty parts of the copper are mixed in a mortar with con-
centrated sulphuric acid, to which is afterward added seventy
parts cf mercury, and the whole triturated with the pestle.
The amalgam produced is copiously washed with water to re-
move the sulphuric acid, and is then left for twelre hours.
When it is required for soldering, it is warmed until it is
about the consistency of wax, and in this state it is applied
to the joint, to which it adheres on cooling.
TO TIN MALLEABLE IRON.
W. M. writes : I tin malleable iron, which comes from the
bath nice and bright, but although I keep it covered, after a
few days it gets red, copper colored in spots, and this color
gradually spreads all over the work. Can you tell me the
cause ? A — The red color is probably derived from oxida-
tion of the iron by the acid left in the poies of thr iron.
The acid rusts the iron and oozes out through the* pores of
the tin by the pressure due to increase of bulk by tiic action
yf the acid upon the iron ; possibly also moisture may be
ibsorbed by the acid through the tin, which is porous.
Rinse the work immediately after tinning in boiling water,
holding 2 oz. sal soda to the gallon in solution.
OLD TINS NO LONGER USELESS
A number of people recently gathered at the Colun.l't
rolling mill, Fourteenth street and Jersey avenue. Jersey City,
at the formal opening of the mill. The industry is a novel
one, being the manufacture of taggers' iron from old tin cans,
and other waste sheet metal. This iron has heretofore been
manufactured almost exclusively in Europe, and the Columbia
Rolling Mill Company is the only American company which
turns out the product in large quantities. The process is
simple. The tin cans are first heated in an oven raised to a
temperature of about 1,000°, which melts off the tin and lead.
The sheet iron which remains is passed first under rubber-
coated rollers, and then chilled iron rollers, which leaves the
sheet smooth and flat. After annealing and trimming, they
are ready for shipment. The tin and lead which is melted
from the cans is run into bars, and is also placed upon the
market. All the raw material used is waste, but the sheet
iron turned out is said to be of good quality. It is used for
buttons, tags, and objects of a like nature. The material used
costing little, and the demand for taggers' iron being consider-
able, it is thought that this is a good opportunity to build up
another American industry.
LEAD ON ROOFS AND IN SINKS.
Tenacity is very slight in some of the metals. An in-
stance may be seen where roofs are covered with lead. The
heat of the sun will expand them, and, of course, it is easier
for the sheets to expand down-hill than up; then, when they
get cold, their own weight will be too great for them, and
they will sooner stretch than creep back up hill; so, in fact,
unless properly laid, the lead roof will to some extent crawl
off its frame- work. The same thing will be seen in kitchen
sinks of lead, where very hot water is run into them. The
lining gets wrinkled, because, after buckling by reason of the
expansion, it will sooner pull thinner than come back to the
ordinary position and condition of surface.
37*
,THE USE OF THE STEEL SQUARE.
The standard steel square has a blade 24 inches long and 2 inches
wide, and a tongue from 14 to 18 inches long and \Y2 inches wide.
The blade is exactly at right angles with the tongue, and the angle
formed by them an exact right angle, or square corner. A proper
square should have tke ordinary divisions of inches, half inches,
quarters and eighths, and often sixteenths and thirty-seconds.
Another portion of the square is divided into twelfths of an inch;
this portion is simply a scale of 12 feet to an inch, used for any pur-
pose, as measuring scale drawings, etc. The diagonal scale on the
tongue near the blade, often found on square?, is thus termed from
its diagonal lines. However, the proper term is centesimal scale,
for the reason that by it a unit may be divided into 100 equal parts,
and therefore any number to the icoth part of a unit may be expressed.
In this scale A B is one inch; then, if it be required to take off 73-100
inches, set one foot of the compasses in the third parallel under i at
E, extend the other foot to the seventh diagonal in that parallel at G,
and the distance between E G is that required, for E F is one inch and
F G 73 parts of an inch.
Upon one side of the blade of the square, running parallel with the
length, will be found nine lines, divided at intervals of one inch into
sections or spaces by cross lines. This in the plank, board and
scantling measure. On each side of the cross lines referred to are
figures, sometimes on one side of the cross line, and often spread
over the line, thus, i | 4 — 9 | — We will suppose we have a board 12
feet long and 6 inches wide. Looking on the outer edge of the blade
we find 12; between the fifth and sixth lines, under 12, will be found 12
again ; this is the length of the board. Now follow the space along
toward the tongue till we come to the cross line under 6 (on the edge
of the blade), this being the width of the board; in this space will be
found the figure 6 again, which is the answer in board measure, viz.,
six feet.
On some squares will be found on one side of the blade 9 lines,
and crossing these lines diagonally to the right are rows of figures, as
seven is, seven 25, seven 33, etc. This is another style of board
measure and gives the feet in a board according to its length and
width.
In the center of the tongue will generally be found two parallel
lines, half an inch apart, with figures between them; this is termed
the Brace Rule. Near the extreme end of the tongue will be found
24-24 and to the right of these 33.95. The 24-24 indicate the two
sides of a right-angle-triangle, while the length of the brace is indi-
cated by 33.95. This will explain the use of any of the figures in
the brace rule. On the opposite side of the tongue from the brace
rule will generally be found the octagon scale, situated between
two central parallel lines. This space is divided into intervals and
numbered thus: 10, 20, 30, 40, 50, 60. Suppose it becomes neces-
sary to describe an octagon ten inches square; draw a square ten
inches each way and bisect the square with a horizontal and per-
pendicular center line. To find the length of the octagon line,
place one point of the compasses on any of the main divisions of the
scale and the other leg or point on the tenth subdivision.
373
ENDLESS TIN PLATES.
A patent has been recently granted for a novel process of
manufacturing continuous tin plates. The plates are made
of steel, and the process consists of producing a sheet of
sbeel of any continuous length and of required width, by
first rolling the metal hot and afterward rolling it cold,
until a proper thickness and perfectly smooth surface is
obtained. Next, the surface of the sheet is scoured, and
then it is afterward passed through a bath of molten tin,
thus receiving its coating. Finally the sheet is subjected to
a rolling operation, under heavy pressure, between highly
polished rolls, by which the tin and steel are condensed and
consolidated together, and the surface hardened and pol-
ished. The inventor states that, by this method, the tin
will be found to be so hardened upon and incorporated with
the steel, as to produce a tin plate which is superior, in most
respects, to any tin plate, wherever produced.
HARDWARE IN HAVANA.
The annual value of the imports into Havana of iron-
mongery and hardware is about $600,000, of which England
supplies barely one-half. Consul-General Crowe states that
German trade in these branches is constantly increasing, but
so far has been confined to such articles as white metal spoons
and forks, locks, cutlery and wire nails, which, however,
form an important aggregate, as the consumption is consider-
able. The German goods are generally inferior to the
English, which are often of better quality than is actually
required. German travelers pay more frequent visits, offer
better terms, and give more attention to the requirements of
the country than the representatives of English firms. The
United States supplies barbed fence wire, cut nails, carpenter's
tools, wheelbarrows, bolts and padlocks, and, according to
the British Consul-General, "inferior gas and water valves. "
Their pumps and plows are described as superior to the
European articles.
CRYSTALLIZED TIN [PLATE.
Crystallized tin plate has a variegated primrose appear-
ance, produced upon the surface by applying to it, in a
heated state, some dilute nitre-muriatic acid for a few sec-
onds, then washing it with water, drying, and coating it
with lacquer. The figures are more or less diversified, ac-
cording to the degree of heat and relative dilution of the
acid. Place the tin plate, slightly heated, over a tub of
water, and rub its surface with a sponge dipped iu a liquid
composed of tour parts of aquafortis und two of distilled
water, holding one common sale or sal-ammoniac in solution.
When the crystalline spangles seem to be thoroughly brought
out, the plate must be immersed in water, washed either with
a feather or a little cotton, taking care riot to rub off the
film of tin that forms the feathering, forthwith dried with a
low heat, and coated with a lacquer varnish, otherwise it loses
its luster in the air. If the whole surface is not plunged at
once in cold water, but is partially cooled by sprinkling water
*l it, the crystallization will be obtained by blowing cold air
•hrough a pipe on the tinned surface, while it is just passing
from the fused to the solid state.
USEFUL RECIPES.
Tinning Acid for Zinc or Brass.— Zinc. 3 oz.; muriatic acid,
1 pt. Dissolve, and add 1 pt. water and 1 oz. sal-ammoniac.
To Solder Brass Easily. —Cut out a piece of tin foil the size
of the surface to be soldered. Then apply to the surface
a solution of sal-ammoniac for a flux. Place the tin foil
between the pieces, and apply a hot soldering-iron until the
tin foil is melted.
To Solder Without /Tea/.— Steel filings, 2 oz. ; brass filings,
2 oz. ; fluoric acid, 1 ^ oz. Dissolve the filings in the acid,
and apply to the parts to be soldered, having first thoroughly
cleaned the parts to be connected. Keep the fluoric acid in
earthen or lead vessels only.
To Tin Brass and Copper.— Make a mixture of 3 Ibs. cream
of tartar. 4 Ibs. tin shavings, and 2 gallons water, and boil.
After the mixture has boiled sufficiently, put in the articles
to be tinned, and continue the boiling. The tin will be pre-
cipitated on the articles.
TO POLISH NICKEL-PLATE.
To brighten and polish nickel-plating and prevent rust,
apply rouge with a little fresh lard or lard oil on a wash-
leather or piece of buckskin. Rub the bright parts, using
as little of the rouge and oil as possible: wipe off with a
clean rag slightly oiled. Repeat the wiping every day, and
ttoe polishing as often as necessary.
375
PATTERN FOR FLARING OVAL ARTICLES.
Of all the great variety of patterns with which the tin man
has to deal, t^ere is probably none that seems more difficult
and c^u :cs mere troub'e and perplexity to make than a flaring
oval pan. By following the annexed diagrams and explana-
tions, the development of this pattern will be seen to be sim-
ple, easy and quickly per-
formed.
First, always describe the
oval from two centers — thus
making the bottom of the dish
— parts of two diameters or.
circles. Separate the circles
when they intersect each other,
and proceed the same as in any
roiu d, flaring article.
Jn Fig. i the compasses
are set at a a, and the large circles described as A A B B, then
set the compasses at b b and describe the smaller circles, thus
completing the oval or bottom of pan.
To make the pattern for the body : In Fig. 2 mark A B
the size of large diameter. Then draw the depth of vessel
and flare desired, as A B C D. Extend the lines C A ant
376
D B until they cross at e, set the compasses at <*, and "describe
the curved lines C D and A B. Make the length A F equal
to A A in Fig. i. Add the locks as shown in dotted lines;
this will be the pattern for side of dish.
In Fig. 3, make a a equal to the small diameter and pro-
ceed the same as in Fig. 2, this will be the end pattern. It
takes two pieces of the large pattern and two of the small to
FIG 4.
make the dish. Should it be found desirable to make the
body of pan in only two pieces, then cut the smaller or end
pattern in two and place it upon each side of the large pattern^
as shown in Fig. 4.
An oval can be made from three or more centers upon the
same plan when desired.
FLARING ARTICLES WITH ROUND CORNERS.
First, to cut the pat-
tern of an oblong %r_
ing dish with square-
cornered bottom and
round cornered top,
in two pieces, of which
Fig. I is the ground
plan, and Fig. 2 the
side elevation.
The height of side
A, Fig. 2, is from a to
bt which is also the
radius for the corners.
First mark off the side
A, Fig. 3 ; then strike
the segments of thecircles a b; this gives the corner. Then
377
murk off £>ne-half of end on each side of a b (c and </), whicfc
completes the pattern for pj
one-half the dish;
Fig. 4. For practice,
we will now cut the pat-
tern so the bottom, sides
and corners will be in one
piece.
One end of the seam
comes on the end piece,
and on the other end in
the center of the corner piece.
Fig. 5, B, shows cone made by putting together the two
flaring sides shown in Fig. 2, A and C, the pattern required
to construct said cone D is the ground plan of cone B
divided into four parts. It will be noticed that the four cor-
ners in Fig. I wrill make D, and that the pattern for the four
corners (a b A, Fig. 3) are equal to C, Fig. 5.
As each corner of Fig. i
is one-fourth of a cone, so
the pattern of each corner,
Fig. 4, is one-fourth of the
pattern C, required to make
the cone B? Fig. 5,
We will now suppose A,
Fig. 2, to be the side view
of a triangular dish con-
structed on the same prfnciciple as A. Each of the
37*
sides will be the same size as required to make the square dish.
only the pattern C, Fig.
5, will be required to be
divided into three parts
for each corner of the
triangle. Fig. 6 is a
ground plan of bottom
of dish. We will cut this
pattern in one piece by
marking off one of the
rides, and then transfer-
ing one-third of pattern
Fig. 8.
A, Fig. 7, to each
side, until we have
used the three sides
and three corner
pieces.
The next step will
be to cut the pattern
of a flaring oblong
dish, top and bottom
having round cor-
ners, of which Fig. 2
will be a side view
and A, Fig. 8, the
ground plan.
If the side and end
pieces in A, Fig. 8t
were removed, B
would be the result.
C is a side view and
pattern for B. Now,
if we wish a pattern
for the A, all that is
required is to cut the pattern for the four corners (C) into four.
379
pieces, and place the side and end pieces between, or, if the
Fig. 9.
pattern is wanted in two pieces,
take a side on which we place two
corners and a half of 911 end
against each corner, as follows:
Or we can suppose Fig. 10, B?
to be the side view of dish having
half-round flaring ends, but ends
of different diameters, as shown
by Fig. 10, A.
We will have the small end
the same as in Fig. 8, so as to use
the same pattern.
B, Fig. 10, showing side view
and radius of large and small \ /
circle.
Fig. 10, C, giving the pattern for one-half of A, Fig. 10.
To have the drawings appear plain, locks were not
added.
MAKING EAVE TROUGH.
The outside line on the larger of the two small diagrams
represents a No. 9
v .^^__L_^^ spring wire clamp,
V^L //^?':":"^":=:x\\ °ne t0 be USe(* at
\C)| f/f, \\ eac^ seam °f tue
III Yr-| trough, The dark
^==J\ III V9\ line on outside of the
jt^_^ _ 1 smaller diagram rep-
^^^ resents a small clamp
used to hold the bead down at the ends of the log. The
log with it 3 trough cia':>pt;vl u,> u.
d to the flat side
large diagram shows the
It will be seen that a j^-inch piece is secured
of the log, which piece projects }£ ur in inch beyond one edge
of the log. A rocker may also be placed under the log.
The log is secured to the bench by hooks or staples with a
long shank fastened to the bench and hooking onto spikes
driven intov the ends of the log.
TABLE OF HEIGHT OF ELBOW ANGLED.
The following table gives the height of pitch of miter
lines for elbows from one inch to twenty-five inches in
diameter. It will be
found of great assist -
" ibl--p -
bow patterns quickly
"y, by do-
ance in describing el-
bow patterns c
and accurately,
ing away with draw-
ings and geometrical
calculations, which
would otherwise be
necessary to get the
correct pitch of elbows.
The accompanying dia-
gram indicates the po-
sition of base and
miter lines. The
height of pitch, that
is, the length from O
to W, is shown by the table for all elbows from one inch to
twenty-five inches in diameter, and of from two to ten
pieces. In two-piece elbows the height of pitch is the diam-
eter of the elbow, and this column is added to make the
table complete. No matter how large the sweep of an el-
bow, the angle of pitch remains the same, and the only dif-
ference to be made in cutting the pattern is to add space as
desired, as indicated at X in the diagram. Locks and seams
are to be added.
•Sj
NO. OF PIECES IN ELBOW.
II
2
3
4
5
6
7
8
9
10
I
I
7-16
9-32
7-32
6-32
5-32
i-8
1-8
3-32
2
2
27-32
18-32
11-32
9-32
1-4
7-32
6-32
3
3
13-16
l-f
1-2
7-16
11-32
5-16
9-32
4
4
i 21-32
i 1-16
13-16
21-32
9-16
15-32
13-32
3-8
5
5
2 I-l6
i 5-16
13-16
11-16
9-16
1-2
7-16
6
6
2 1-2
i 5-8
i 3-16
31-32
13-16
11-16
5-8
9-16
7
7
2 29-32
T 7-8
3-8
i 1-8
15-16
13-16
9-16
5-8
8
8
3 5-16^ 1-8
9-16
i 1-4
i 1-16
29-32
13-16
23-32
9
9
3 23-32
2 13-32 13-16
i 7-16.1 3-16 i
29-32
13-16
10
10
4 1-8
2 II-l6
i 9-16 5-16,1 1-8
29-32
ii
ii
4 1-2
2 15-16' 3-16
i 3-4
7-16 i 1-4
3-32
i
12
12
4 15-163 3-16 3-8
i 7-8
9-16 i 3-8
3-16
i 1-16
13
13
5 3-8
3 7-8 9-16 2 1-16
23-32 i 15-32
5-i6
i 5-32
14
14
5 3-4
3 23-32( 3-4 2 7-32
7-8
i 9-16
3-8
i 1-4
15
15
6 5-32
4 3I-32J2 3-8
i 11-16
1-2
i 11-32
16
16
6 19-32
a. 1-4
3 5-32 2 17-32
1-8
i 13-16
19-32 I 7-16
17
17
7
4 7-32
3 6-162 11-16
i 15-16
11-161 1-2
18
18
7 3-8
4 25-32
3 9-162 27-32
3-8
2 1-32
25:321 19-32
19
10
5 1-163 3-4
3
1-2
2 1-8
7-8
i 11-16
20
20
8 1-4
5 5-163 31-32 3 3-16
21-32 2 1-4
i 25-32
21
21
8 5-8
5 19-324 5-323 11-32
13-162 3-8
1-161 7-8
22
22
9 1-16
5 27-32 4 3-8 3 1-2
I5-l62 1-2
3-16.1 15-16
23
2}
9 7-166 3'3?'4 9-163 21-32
3 1-16 2 10-32
9-32 2 1-32
24
24
9 7-8
6 3'8 4 3-4 '3 i3-i6
3 3-162 11-16
3-8
2 1-8
25
2510 9-32
6 5-8 4 15-163 15-16
3 5-162 13-16
7-162 3-16
1
1
The table is adapted to right-angled elbows only. The
line of figures at the top of the table indicate the number of
pieces of which elbows are to be made. All other figures are
in inches, the first or left hand column being the diameter of
elbows, the remaining column being the height of pitch
required.
ZINC AS A FIRE EXTINGUISHER.
Zinc, placed upon the stove, in fire or in grate, is said to
have proved itself an effective extinguisher of chimney fires.
To a member of the Boston Fire Department is reported to
be due the credit of successfully introducing this simple
scheme. When a fire starts inside a chimney, from whatever
cause, a piece of tin sheet zmc, about four inches square, is
merely put into the stove or grate connecting with the chim-
ney. The zinc fuses and liberates acidulous fumes, which,
passing up the flue, are said to almost instantly put out what-
ever fire may be there. It certainly sounds simple enough.
3S2
HOME-MADE ASH SIFTER.
An io\va correspondent sent Good Housekeeping the fol-
lowing diagram and description of a home-made ash-sifter,
any tinner or other person may construct : " I got my idea of
it from seeing sand sifted by
throwing it on a sieve that
stood slanting. The wire
sieve (already wove) can
be bought at a hard-
ware store for twenty
cents a running foot, and it
is two or two and a half
feet wide, and this can be
tacked to a frame made to
fit the sifter, one end just
reaching over the box for
coal, and the other end ex-
tending nearly to the top
of the sifter. There is no
shaking, nor any dust.
Ashes are emptied in the
top of the sifter, the coal
being carried over the sieve to the coal box, while the ashes go
through into the ash box. The sieve should be two and a
half feet long. Can use a sliding or swinging cover."
TO DESCRIBE A MITER.
As there seems to be some interest manifested in regard to
tbj miter question, and nothing definite as to the desired
miter lias been given, I wish to submit the following rule:
Let a in diagram be the size of the article upon which the
miter is to be cut ; strike a circle full size, or from edge to
edge as shown at e and b of the diagram ; draw a line as
shown by </, from e to b> which divides the circle equally. If
you wish a square miter set compass at e and obtain one-
fourth of the circle as shown at figure 2, and draw line b f
3^3
intersecting trie circle where the p >int of the compass shows
one-fourtu of circle. Cutting this line you have a s juare
miter. Sho.ild you wish your work to form six squares, take
the sixth of a circle as shown at figure i by line c b ; or, if
eight squares, one-eighth f circle, and intersect the circle at
point designated by compass.
A miter may be cut for any angle desired by the same
rule ; divide the circle into the number of squares wanted,
and proceed a> shown above. This rule does not apply to
forming a miter for gutters.
TO PESCRIBE A PATTERN FOR A FOUR-PIECE
ELBOW.
Three and four piece elbows have very largely taken the
; old right-angled elbow, on account of their bet-
ter appearance, and also
becajse they lessen ob-
struction to draft. The
machine-made article is
k pt in stock for all
common sizes, but the
'inner is liable to be
called upon at anytime
to make such an elbow,
on account or stock be-
ing sold out or of un-
usual size, or other
cause. Herewith are
given diagrams and ex-
planations which will
enable any tinner t^
construct a pattern for
any desired size.
Let AB E D,Fig. i,
be the given elbov
A98 7
ft 4. 821B
draw the line F C ; make F M equal in length to one-half
the diameter of the elbow, with F as a center ; describe the
arc K L ; divide the arc K L into three equal parts ; draw
the lines F H and F I ; also the line I H ; divide the section
H K into two equal parts, and draw the line F G ; draw the
lins A B at right angles to B C ; describe the semi-circle.
A N B ; div'^~ +he semi-circle into any number of equal
parts; from me points draw lines parallel to B C, as I, 2, 5,
etc.
3*4
Set off the line ABC, Fig. 2, equal in length to the cir-
cumference of elbow A B ; erect the lines A F, B D and
C E ; set off on each side of the line B D the same number
of equal distances as in the semi-circle A. N B ; from the
points draw lines parallel to B D, as i, i, 2, 2, etc. ; make
B D equal to B G ; make A F and C E equal to A J ; also
each of the parallel lines, bearing the same number as i, i,
2, 2, 3, 3, etc. ; then a line traced through the points will
form the first section ; make F G and E J equal to H I ; re-
verse section No. i ; place E at G and F at J ; trace a line
from G to J ; make G H and J I equal to P 6, Fig. 67, or
to D K. Fig. 68; take Sec. No. i, place F at H and E at
i, and trace a line from H to I ; this forms Sec. No. 3
and 4.
Edges to be allowed.
In the West Indies the work of coaling ships is performed
by negresses. Like ants going to and fro, each of these
women, with a load of coal weighing about forty pounds,
carried in a basket on top of the head, climbs the eang-piank,
and the bunkers are filled in a wonderfully short time. For
this arduous work, a cent a basket is the general price, but
night work and emergencies double the rate. A penny is
given to each woman as she fills her basket, and the number
given out forms a check on the tally kept by the parties
receiving the coal. The name of the firm owning the coal
pile is stamped on the coins, which are current throughout the
: slands.
3*5
A WIRE FLOWER STAND.
Tinners are ingenious, and can generally make anything
from sheet metal, wire, or other light material, which tliey
take a fancy to try their hands at. Many have made orna-
mental articles at il'i
moments with which to
beautify their own home,
or possibly that of some
young lady. By their
skill in thi^ direction
they ore frequently able
to make presents yi arti-
cles of their own make,
which are not merely or-
namental, but also useful.
This is commendable,
and such eki!! and enter-
prise is wo/thy Of encour-
agement.
We here present an
illustration of a new
round flower-stand con-
structed in three j arts,
which can be take;* asun-
der so as to convert the
stand at will into a rustic
table. The cut is taken from the London Ironmonger^
which says that the originator of the flower-stand is doing
well with it.
TO STRIKE AN OVAL OF ANY LENGTH OR
WIDTH
In arecet't number of the American Ar isan, which I
have mislaid, some one asks for a rule to stride nn oval of
any desired width and length. There are several different
ways of striking an oval or ellipse, but I find the one 1 en-
close you the most practical.
Let A B and C D equal width jind length. On the line
CD lay off the width of oval a: C C. Divide the distance
from E to D into thr e equal parts, and lay off two of the
parts thus formed on either s'de of the center F, as G and
H. Span the dividers from H to G, and, with F as a center,
check the line A B, as at M and K. Draw 1'ne intersecting
the points H M G K, and, with tin* radius G D and K. B
strike the ends and sides of oval.
386
AN ORNAMENTAL PAPER HOLDER.
Tinners with leisure who desire to use their handiwork in
making something for Christmas, will be interested in the
accompanying illustration which we reproduce from a
European journal. It is intended for a holder for paper,
magazines, or sheet music.
HEATING AND VENTILATION.
Much continues to be said and written about heating and
ventilation, and some may consider it a worn-out subject ; but
so long, as millions of people continue to be poisoned by
impure air, agitation to secure reform cannot be overdone.
It will dd':no harm, therefore, to again name some of the evi-
dences and consequences of a lack of ventilation: Head-
ache; dull pressure on the lungs ; lungs become parched, pro-
ducing irritation ; dfyness of the throat, producing sore
throat ; a feverish condition of the whole system. These are
some of the immediate consequences, but by no means embrace
3*7
all the ultimate evil effects. It shou'd be the duty of all
fnrnacemen to call the attention of their patrons to these
c c
7
Fig I
matters. Furnaces are often blamed for the quality of air
supplied, while the fault lies solely with the operators in not
making provision for the supply of pure air to the furnace,
and proper ventilation.
This subject will not take care of itself. We must first
feel lhat fresh air is worth taking some trouble to obtain, and
then we must study ho\v to obtain it without the body's
becoming either chilled or overheated in summer or winter,
in the daytime or in the night. At night more care needs to
be taken to secure ventilation, because there are no doors
being opened ; no stirring about to promote circulation.
Especially should pure air be supplied to the sick room, and
the vitiated air removed.
In summer we depend on the natural movement of the air
for ventilation, windows and doors being open more or less.
In winter, with the house closed up, it requires thought and
effort to provide fur a change of air in apartments. It must
be remembered that, under natural conditions, air moves hor-
izontally, according to the direction of the wind. Heat causes
air to move in a perpendicular direction. In dry weather,
heated air andsmoke will rise until the same density of atmos-
phere is reached, which soon results from loss of heat. When
the at mo phere contains a great deal of moisture, s.noke will
descend, on account of quick condensation and loss of heat.
This principle, understood by all must be kept in view in.
any plan for ventilation. Suppose we wish to ventilate a
room in the morning when the air outside has become a little
warmer than the air inside. The upper part of a window
being opened the warmer air outside would blow across the
lop of the room, leaving the air below undisturbed Now,
if we open the window at the bottom we shnll secure a cii>
Culation of air in the room. While the outside air is warmer
we do not notice the draft. Suppose we now go 'Lito the
kitchen, where the windows are only opened at the bottom
and raised halfway up; we shall feel the lower part is cool,
while the i.ir in the upper part is undisturbed. ]\o,v, if we
open the top of the window and divide the difference so as to
have the top and oottom open, we shall have a circulation.
Or if we open a door and hold a candle at the top and then
at the bottom, we will see the same circulation illustrated by
the cold air flowing in at the bottom and the hot air out at
the top. These experiments furnish the natural laws which
should govern ventilation.
Carbonic acid gas from respiration and other, exhalations
of the body, as well as gases caused by decayed vegetation in
cellars, or from garbage, sewer emanations or any kind of
filth are all poisonous, and, being heavier than pure air, sink
to the bottom of a room by gravitation. It is a gross error
to suppose, as many do, that the foul air rises to the ceiling
and remains there. The sickness and death of children, often
attributed to other causes, arises from blood-poisoning from
the foul air near the floor to which children are much more
exposed than grown persons.
The illustrations given herewith will show where
the foul air is and how it is confined unless drawn
off by some superior force. In Fig. i, A represents a
cellar, DD the walls, CC the surface of the ground outside of
the house. Foul air seeks the lowest space by gravitation,
therefore all below CC is foul air because there is no ventila-
tion to draw it away. So long as it remains stagnant, pure
air will not take the place of the foul. JVow, if we place a
furnace in the cellar, as shown in Fig. 2, and take the air
from the same, it would amount to almost the same thing as
living in the cellar, for you breathe the same air. Opening
the windows furnishes an outlet for the warm air and thus
Cools off the furnace; but the same foul air, dust and ashes
are brought up from the furnace for inhalation.
Again, if the rooms are closed, the air from the furnace
v ill rise to the ceiling, then pass to the windows, where the
temperature will be reduced, and will then descen I to the
floor and down the sides of the hot-air flue to the furnace to
be reheated and sent up again. This has been proven by ex-
periment. The children will be the first to be affected by
this reheated foul air.
How can we obtain pure air? By ventilation. How can
ventilation be secured? In various ways. The principal
method used is the ventilating shaft. One shaft is generally
sufficient for one dwelling, and is usually in the firm of a
large chimney, as shown in Fig. 3. A is the chimney; B is
a heavy sheet-iron pipe, with air space around the pipe for
ventilation; C is an opening into tne pipe B for connection
with the furnace; Z>is a place for cleaning out just below the
furnace opening; these two openings should be in the cellar
where the furnace is; C is the place for the kitchen stove,
which will supply sufficient heat for ventilating the house dur-
ing the summer season. Fig. 3.
We will next consider how to supply the
furnace with pure air. It should be taken
from the side from which come the pre-
vailing winds. Of course, care should be
taken that it is not polluted by a sewage
hopper, water closet or other source of con-
taination. The opening into the air-duct
should be two feet or more above the ground,
and should be covered with fine wiie gauze.
The air-duct should be carried along the
ceiling of the cellar until it reaches the fur-
nace, as shown by dotted lines in Fig. 2,
then drop down at the side of the furnace to
the bottom. The space around the furnace
should be made air-tight. Any foul air in
the cellar will be drawn into the fire-box of
the furnace to promote the combustion of
the fuel. The area of the cold-air duct
should, in no case, be less than half the area
of the hot-air pipes.
In setting a furnace, particular carej
snould be taken to see that the chimney has
a good draught. There should be sufficient height between
the top of the furnace and the ceiling of the eel ar to permit
a good rise for all the hot-air pipes from the furnace.
If there is not sufficient height in the collar to admit
of this, the furnace should be set into a ^it dug out
below the cellar floor and bricked up. Ample room
should be allowed in front ,of the furnace for cleaning
out ashes. All the pipes should be kept as close to the
furnace as possible. If any hot-air pipe is extended more
than fifteen feet from it, it should be encased with about
half an inch space around, with both ends of casing entirely
closed, to prevent the loss of heat. The location of the
furnace should be so that the length of hot-air pipes shall be
about equal. The smoke-pipe should be run directly to the
chimney. Dampers should be placed ia all the hot-air pipes
close to the furnace, and. when the pipes are not in use, the
dampers should be closed. The vapor-pan should be placed
where the water will not boil. In some cases, if set on the
top of the furnace, the water will boil over aii,l crack the
furnace. A proper place must be provided for it. In a brick-
set furnace, the vapor-pan should be automatic in action,
being connected with an outside pan with a ball and cock.
Without this arrangement it is hard to keep up a regular
supply of vapor, as this is a point generally neglected.
In order to distribute the heat through the rooms, the
ventilating registers must be located in the proper places.
They should be placed in the floor near the windows or in the
coldest part of each room, so as to draw the heat to tliat
part. Never run a hot-air pipe up an outside wall if you
wish success with your work. If ventilators are put into a
side wall, be sure that they extend down entirely to the floor,
otherwise there will be a cold stratum of air next the floor,
causing cold feet. A failure to do this, causes children to
have cold feet at school. People frequently suffer in a simi-
lar way at church.
TWO SPINDLE MILLING MACHINE.
The illustration represents a milling machine of new de-
sign, recently built by E. W. Bliss Company, of Brooklyn,
N. Y., for use in their own works.
As will be seen, the general arrangement is that of a planer,
but, in the place of the ordinary planer tools, are substituted
vertical spindles for butt milling.
The table has a longitudinal travel of 36 inches, and is fed
by a screw which may be operated by the hand-wheel shown
at right side of bed, or fed by power, in either direction.
Four speeds for feed for the table are provided, and in
addition a power '-rapid transit" motion, which is operated
to run the table in either direction, by means of the hand-iever
shown to the right of bed. The quick motion is especially in-
tended for running the table back alter the cut is finished, and
being entirely independent of the cone feed, both can be In
391
operation atone and the same time, thus saving the trouble
of throwing off the cone-feed in order to run the table back
for starting a new cut.
The cross-head is raised and lowered by power, much in
the same manner as in a planer, and in addition ea< h spindle
has an independent vertical adjustment of two inches oper-
ated by the hand cranks shown at the upper boxes on saddles.
Each saddle is capable of independent lateral motion,, oper-
ated by the large hand-wheel at front, and has also a p >wcr
attachment for feeding, supplied with four changes of speed.
As in the case of" the table, the saddles nay be moved
independently from the power feed while the latter is in oper-
tion. The cross-head is made of sufficient lengtli to allow
the saddles to be run out far enough to bring the nulling cut-
ters outside of the housings, between which the distance is
fifty-four inches.
The machine illustrated was built for special v\ork not
requiring a long table, but the latter can be made of any
length required, and the builders are now filling several orders
for machines with five to six feet length of table.
The driving-shaft, carr'ed by cross-head, is splined its
length between bearings to allow for the lateral motion of the
saddles, and is driven from the floor counter by the familiar
arrangement of belting shown, which dispenses with the
necessity of a tightener to make up for the -vertical arljirrt-
ment of the cross-head.
In some of the machines now in corpse of construction,
the arrangement is such as to allow the floor counter to be
dispensed w?ith, and one at top of machine to be substituted,
which, in some cases, might be considered preferable.
By the use of the two spindles on the work for which this
machine was designed, and with special attachments to facili-
tate the setting, this tool is now doing work that heretofore
required the use of five planers, thus proving itself a most val-
uable addition to the equipment of a machine shop.
EXPLOSION OF A DOMESTIC HOT WATER
BOILER.
Explosions of domestic hot water boilers attached to
cooking ranges, water-backs in ranges, etc., through freezing
up of the pipes in cold weather, are becoming so frequent
that it may not be out of place to give an account of one o*
the most destructive ones that has occurred recently, and
point out its cause.
The boiler in question was used in an hotel in a large city
392
in one of the Northwestern States, where the temperature is
very low at times. It was connected to the kitchen range,
the range was a very large one, and the heating surface was
furnished by a coil of j^ inch pipe, placed near the top,
instead of the cast-iron front or back, such as is commonly
used in the smaller ranges in private dwellings. The con-
nections to the boiler were made in the usual manner ; the
accompanying cut shows its essential features.
The operation of all boilers of this sort is as follows :
The connections being made, as shown in cut, the water
is turned on from the main supply, and the entire system is
RANGE
fil. d with water. When it is filled, and all outlets are
closed, it is" evident that no more water can run in, although
the boiler is in free connection with, and is subjected to, the
full pressure of the source of supply. When a fire is started
in the range, and the water in the circulating pipes, or
water-back, is heated, the water expands, is consequently
lighter, and flows out through the pipe into the boiler at A,
as this connection is placed higher up than the one at B ;
this starts the circulation, and the water, as it becomes
393
heated, constantly flows into the boiler at A, and rises to the
upper part of the boiler, while the cooler water at the bot-
tom of the boiler flows out into the circulating pipes at B,
and, if no water is drawn, a slow circulation goes on, as heat
is radiated from the boiler, in the direction indicated by the
arrows, the water at the top of the boiler always being much
hotter than at the bottom. WLien the hot cock is opened,
cold water instantly begins to flow into the boiler at D, by
reason of the pressure on the city main, and forces hot water
out of the boiler at C. Thus it will be seen that hot water
cannot be drawn unless the cold water inlet is free, and it is
equally evident that cold water cannot enter the boiler unless
the hot water cock or some other outlet is open.
The above points being understood, we are in a position
to investigate the cause of the explosion referred to, which
killed one person and badly injured twelve or thirteen others,
besides badly damaging the building.
On the morning of the explosion fire was started as usual
in the range about four o'clock a. m- It was found, on try-
ing to draw water, that none could be had from either cold
or hot water pipes: it was rightly judged that the j>ipes were
frozen. The fire was continued in the range, however, and
the breakfast prepared as best it could be, and a plumber sent
for to thaw out the pipes. He arrived on the premises about
seven o'clock, as would naturally be the case. He opened
both hot and cold water cocks, and, getting neither steam nor
water, concluded there was no danger, and proceeded to
thaw out some pipes in the laundry department first. About
an hour afterward the explosion occurred. The lower head
of the boiler let go, and the main portion of the boiler shot
upward like a rocket through the four stories of the hotel
and out through the roof.
The coroner held an inquest on the remains of the person
killed, and some of the testimony given, as reported in a
local paper, would be amusing were it not for the tragic
nature of the affair which called it out. The usual expert,
with the usual vast and unlimited years of experience, was
there, and swore positively to statements which a ten-year-
old boy who had been a week in the business ought to be
ashamed to make. He had examinee! the wreck with a view
to solving the mystery (?) The matter was as much of a
mystery now as oh the day of the explosion. His theories
were exploded as fast as he presented them. The boiler must
have been empty. If it had been full of water, it could not
possibly have exploded, etc., etc. And then a lot more
nonsense about the "peculiar" construction of the boiler.
394
As a matter of fact, there was nothing peculiar about the
boiler or its connections. Everything was precisely like all
boilers of its class, of which there are probably hundreds of
thousands in daily operation throughout the country, and,
moreover, they were all right.
Now let us inquire what caused the explosion. Every-
thing was all right at eight o'clock the previous evening, for
water was drawn at that time. The fire was built in the
range at four o'clock a. m. It is admitted that the cold
water supply pipes were frozen, for no water could be had
for kitchen use. It is also proved absolutely that the hot
water supply was frozen or otherwise stopped up, by the fact
that at seven o'clock the plumber who came to thaw out the
pipes opened the hot water cock and got "neither water nor
steam." Here was his opportunity to prevent any trouble,
but he let it pass. Any one who understood his business
would have known that there must have been a tremendous
pressure in the boiler at this time, as the range had been fired
steadily for three hours; there were about eight square feet
heating surface exposed to tne fire by the circulating pipe in
the range, and there had been no outlet for the great pressure
which must have been generated during this three hours
firing. The blow-off cock should have been tried at once;
if this were clear, and tha probability is, from its proximity
to the range, that it was clear, the pressure could have been
relieved, and disaster averted. If the blow-off proved to be
stopped up, then the fire should have been at once taken out
of the range. At the time the plumber opened the cocks
connecting with the boiler, it probably was under a pressure
of 400 or 500 pounds per square inch. An ordinary cast-
iron waterback such as is used in small ranges in private
houses would have exploded shortly after the fire was built,
but it will be noticed that the heating surface in this case
was furnished by a coil of 1*4 -inch "pipe; this was very
strong, and the boiler was the first thing to give way, simply
because it was the weakest part of the system.
Accidents of this sort can be easily avoided by exercising
a little intelligence and care. The hot water cock should
always be opened the first thing on entering the kitchen
every morning. If the water flows freely, fire may then be
started in the range without danger- If it does not flow
freely, don't build a fire until it does.*
* A CEMENT TO MAKE JOINTS FOB GRANITE MONUMENTS—
Use clean sand, twenty parts; litharge, two parts; quicklime,
one part, and linseed oil to form a thin paste.
USEFUL SHOP KINKS.
jles, or rise of elevations
The usual rise given to
furnace pipe elbows is
one inch to the foot. A
rule to obtain the desired
result is as follows, and
is almost identical with
the one commonly used
to get the height and
pitch of miter line of
riglit-anglod elbows. It
i > applicable to any sized
tliroat and any sized el-
b.rvv; also, to elbows
wit,h any number of
pieces or sections.
First draw lines a c
and c 6, Fig. 1, at right
angles to each other.
From point c on line c ft,
measure off 1 foot, and
perpendicular from the
point thus obtained erect
line d to r, which is the
desired height you wish the elbow to rise, or angle from a
true right-angled elbow, in this case one inch to the foot.
From point c as center, draw the arc a to r. From point r
draw the line r c for base line. This will give the correct
elevation, as proof clearly shows by the dotted lines c to z
and r to m; these show the continuation that the elbow leads
to, namely, as in this instance, 1 inch to the foot, or 1 foot
in 12 feet. The line c to x is 1 foot, and from x to z, 1 inch.
If an elbow of four pieces is desired, divide the arc or
curve r to a into six equal parts; if an elbow of three pieces
or sections is wanted, divide same into four equal parts.
From point c for a four-piece elbow, draw line c to *, and
from point n, where inner curve of elbow intersects line c s,
draw line n to I parallel to line c r, and same intersecting
line r s at I. This much gives the pitch and rise for miter
line for a four-piece elbow of the desired elevation. For a
three-piece elbow the dotted lines from point k on the inner
890
FIG. 3.
curve to points u and o on outer curve, give the miter de-
sired.
I have also shown a
smaller-sized elbow in
the drawing to show how
the rule works, and is
applied on same. It*i ,
of course, not necessary
to give the same size <.f
throat, as is given in the
drawing, nor the same
outside sweep. This rule
will suit a::y case or sized
elbow as m:iy be desire 1.
and as one becomes f:i-
miliar with the workiry
of the rule, some of the
other lines need not be
drawn out, but are hero
given to make the draw-
ing complete.
The above is given to
get the complete data for
side elevation which are
necessary to develop the •
patterns for the different
sections of an elbow. To develop the same I will give a
quick snap rule, which comes so near right as to be prac-
tically almost correct. I will, however, first give a good
snap rule for angles.
If Fig. 3 is examined, it shows the usual long and tedious
geometrical method of obtaining miter lines for both a two-
piece, and also a three-piece angle, both of the angles being
of the same pitch. The solid lines are for a three-piece angle,
and the dotted lines are for a two-piece angle.
Now, to do away with all this drawing, and to get a quick
and very nearly correct method to obtain the desired result,
suppose an angle is wanted as is given by the lines a b and
a to c, Fig. 3, the diameter to be as full drawing requires,
proceed as follows: First measure off the distance which is
the size of diameter wanted, from a to b; do the same from
a to c, and from points thus obtained, which are c and 6,
draw the line d from c to b. Then from either line, a c or
line a 6, draw at right angles the line a to a?, as shown, the
line a x intersecting line d at x. This much gives the re-
quired elevation for miter line of a two-piece angle as called
397
for; line </from c to x is miter line, a to x is height of rise,
and a to r, base line, which is size of diameter called for.
The line x to a divided into half gives the point r where the
miter line intersects., of a three-piece angle ; r to a is height,
a to c is base line, and c to r is miter line, as will be seen by
dotted line in drawing. Twice the length of distance of line
from points a to is the width of outer curve of center sec-
tion. You must, ot course, allow for laps or burrs for join-
ing same together when cutting pattern.
Compare this with the solid line center section of full side
elevation, and see how much quicker this method is over the
old way. When once accustomed to use this method, you
will use no other. This rule is absolutely correct for a two
piece angle, and varies so little on a three-piece angle from.
'rig. a
being absolutely correct, as that the variation is practically
of no moment.
To develop the stretch-out, Fig. 2, lay out the full length
of circumference, as is shown in Fig. 2 from a to b, and
divide this length into six equal parts as in drawing. Make
the center line, No. 2, same height as required, as in this
case for the two-piece angle of Fig. 3. Next divide the
right and left lines nearest to the center line, into four equal
parts, and mark of one off these parts nearest to the top of
each line ; and do the same as to s ^acing to the lines nearest
to the end of stretch-out, as lines No. 4 and r, but with the
difference that you mark off one space at the bottom of each
Kne as the drawing fully shows. Continue the center line
39s
indefinitely downward, and with dividers strike the arc i, 2
and 3, cutting lines at points i, 2 and 3. Draw line b in-
definitely upward, reverse the dividers, and with line b as
center In", draw the arc from point 5 to point 4, cutting
points 5 a.id4; d;> the sa.ne on the other end. Then draw a
Straight line from paint 3 to 4, and same from i tor. This
completes the pattern. Allow for locks or laps on both
ends, and miter line^, of course.
The met ho 1 given above is an old one, but not so uni-
versally 1- no\\ii a nong tinners as its merits deserve. This
method is also applicable to develop the pattern for elbow
as given in Fig. i. I use it for all kinds of elbows.
TO DRAW ANY OVAL WITH SQUARE AISTI>
CIRCLE.
The following is a correct rule to draw any size or ova!
tised in the tin shop, with square and circle :
Draw the line from I to 2, which is the length of the.ovai
Draw line from center to 3, which is one-half the width, and
draw a line from i 103. Set compass from i to center ;
leave one point on i, and mark 4. Set compass from center
103. Leave one end (of compass) in center ami mark 5. Set
compass from 4 to 5. and from 6 draw head lines of circles 7
and 8, and clut 7 and 8 from points i and 2. Set compass
from 7 to 7, and mark 9 from 7 7 and 8 8. Complete oval
from 9.
399
RAIN WATER STRAINER.
I hand you a sketch of a rain water strainer which I have
put up and which gives good results. It is eighteen
inches high, twelve inches in diameter at the half-circle, five
and a half inches length of bottom, and five inches deep.
Allow for all seams.
At A'2, D> B2y B> represents the outside of finished
strainer. K "ts a, section of circular top hinged at B* and
fastened with a turn button. The dotted lines at E show
the section of circular top, A*, partly open; m is a galvanized
strainer with three-eighth inch holes. The strainer rests
upon supports at the ends, and may be removed at will. /.
is a tin strainer with one-eighth inch holes, and is soldered in
place. F and G are three-inch inlet and outlet. 2 2 are
straps on back side, by which the strainer is fastened to ths
building.
As will be seen, the top strainer catches the refuse whic5i
is washed from the roof and gutters, and is easily taken out;
the finer particles ate <• t^ht below ap-l irt1. -l»e removed
when the top strainer is out.
400
OVAL DAMPER.
Inclosed please find method of obtaining an oval damper,*
tliat when closed in, the pipe will be at an angle of 45°.
Let A B C D
lepre
sent the pipe, and E F
the line through the pipe at
an angle of 45°, which will
be the position of the damper
when closed. Divide the
semi-circle into any even num-
ber of equal parts, as, I, 2, 3,
4, etc. (even numbers, because
in doing so you obtain the
center line of the short diam-
eter of the damper). Carry
lines up until they cut the
line E F as dotted lines, then
draw solid lines across, and
at right angles to the line
E F, and number them to
correspond with spaces in
semi-circle, as I, 2, 3, 4, etc.
With the dividers step from
a to i on dotted line, and
with one point of the dividers
at a'; cut the solid line I each
side of the line E. F. Step
from b to 2, and with one
it
j ytf
point of the dividers on b', cut the solid line to both sides of
the line E F, and so on until all the spaces have been trans-
ferred. Now set the dividers so as to draw an arc through
the points 5, 6, 7, both sides of the line E F, and then set
them to draw the two end circles, as n, 12, n, and 1,0, I.
Draw a' line free hand through the points from i to ,5, and
from 7 to n, both sides of line E F, and you have the re-
quired damper.
The same method is used to obtain the shape of a hole in
piece of sheet metal that a pipe is to pass through on an
angle. For instance, let A B C D represent a pipe, and
E F a roof through which the pipe passes ; we want a piece
of iron or tin laid on the roof for the pipe to pass through ;
we want to know how to get the shape of the opening.
Employ this m"thud and it will give you the required article
A TAPERING ROUND-CORNERED SQUARE
RESERVOIR.
'Not long since, there was an inquiry in your columns for
a pattern for a tapering, round-cornered square reservoir. 1
give herewith diagrams for constructing such a pattern :
Fig. i is the size, top and bottom (A C F H D B G E is
the top, and I.K NP LJOMis the bottom), and Fig. I
the upright height. Take the
perpendicular height ad, Fig
I, and mark it off from h to k,
Fig. 3. Take the radius for
the corners d C, Fig. I, and
mark it off from h to i, Fig.
3, also the radius dK; mark
off from K to 1, drawing ;». line
from il to cut the line li K,
which gives the slanting height
and the radius required for
striking the corners. Draw the
lines I 1C and AC, Fig. 4, the
same length as I K, Fig. 2, am1
the same distance apart as 1 to i,
Fig. 3 ; prolong the lines A I
and C K, Fig. 4, till Ac and
C d equals to i m, Fig. 3.
With radius d C, Fig. 4, using
d and c as centers, strike the
curves C F and A F, and, with
a radius d K, Fig. 4, using the same centers, strike the
curves K N and I M. Take the length of the large quar-
Fig. 3-
ter-circle 1) H, Fig. 2, and dot off the same distance from
C to F, Fig. 4; make A R e^jual to C F. and draw
4O2
lines from E and F to the ceniers c and d; draw EG
and M O at right angles with E c. Take the dis-
tance from A to C, and make the same distance from
E to G and M to O, Fig. 3. DrawGe parallel to EC.
From G mark off point e, the same length as E to c, then,
using e as center, strike the curves G B and O J, making the
curve G B equal to A E ; draw line from B to center c,
draw B T and J R at right angles to Be, taking the distance
from B to S, Fig. 2, mark off the same distance from B to
S and J to R, draw S R parallel with <B e, and proceed in the
same manner with the .other end; adding on the laps, as
shown, will make the pattern complete in one piece, being
joined together at R S.
PATTERN FOR T JOINTS.
The following rule is a short and explicit method of ob-
taining a pattern for T joints where different diameters are
required. Suppose, for instance, a T is required whose diam-
eters are 3 and 8 inches respectively.
Divide the stretch-out, a a (which must be the exact
length required to form up
3 inches, allowing for
locks as shown by dotted
lines) in center as shown
in the figure. Then
divide each half equally
between 6-7 and 7-8 as
shown by indefinite lines
2 and 3. Now spread the
compass to 8 inches, which
is the diameter of the
large pipe, set one point
at 4, and the other at
6; strike a circle to 7;
then set compass on the
other line at 5 and draw
circle 7 to 8. Cut out the circles, and you have your pattern.
The same rule applies to any diameter by spreading compass
to the larger diameter and striking the circle on the stretch-
out required for smaller diameter as shown above.
Ireland has seventy-six collieries — nine in Ulster, seven
in Connaught, thirty-one in Leinster, and twenty-nine in
Minister. Very few of these are being worked.
403
NOVEL DRAWING INSTRUMENT,
A pair of dividers, or
compasses, which will de-
scribe any figure is shown
herewith. It is of Eng-
lish origin and very simple.
The former, or template
A, is affixed to one le<:,
and beats against the mid-
leg B, around which, of
course, revolves the work-
ing leg. By this means
the drawing pen or pencil
is moved in and out in an
obvious manner. Speci-
mens of the work are
shown in Fig. 2.
The quality of wood is determined by the number of
spirals. The best has about thirty " crinkles " in an inch.
404
TO DESCRIBE A PATTERN FOR A TAPERING
SQUARE ARTICLE.
Erect the uerpendicular line G E ; draw the line A B
at right angle to
make E K
G E ;
equal to the slant
height, and draw
the line C D par-
allel to A B; make
AB equal in
length to one side
of the base; make
CD equal in
length to one side
of the top or
smallest end, draw
the lines AGand
B G, cutting the
points A C and
BD, Gasa center
with the radii G C and G A. Describe the arcs K M and J I ;
set off on the arc J I, J A, B H and H I equal in length to A B,
and draw the lines J G, H G, and I G, also the lines J A, B H,
HI, and KC, D L, L M.
Edges to be allowed.
THE PAINTING OF IRON.
Cast and wrought iron behave very differently under
atmospheric influences, and require somewhat different treat-
ment. The decay of iron becomes very marked in certain
situations, and weakens the metal in direct proportion to the
depth to which it has penetrated, and, although where the
metal is in a quantity this is not appreciable, it really becomes
so when the metal is under three fourths of an inch in thick-
ness. The natural surface of cast iron is very much harder
than the interior, occasioned by its becoming chilled, or by
its containing a large quantity of silica, and affords an excel-
lent natural protection, but, should this surface be broken,
rust attacks the metal and soon destroys it. It is very desira-
ble that the casting be protected as soon after it leaves the
mold as possible, and a priming coat of paint should be
applied for this purpose : the othei coats thought requisite
can be given at leisure. Jn considering the painting of
wrought iron, it must be noticed that, when iron is oxidized
by contact with the atmosphere, two or three distinct layers
405
of scale for 1.1 on the surface, which, unlike the skin upon
cast iron, can be readily detached by bending or hammering
the metal. It will be seen that the iron has a tendency to
rust from the moment it leaves the hammer or rolls, and the
scale above described must come away. One of the plans to
preserve iron has been to coat it with paint when still hot at
the mill, and, although this answers fur a while, it is a very trou-
ble^ome method, which iron masters cannot be persuaded to
adopt, and the subsequent cutting processes to which it is
submitted leave many parts of the iron bare. Besides, a good
deal of the scale remains, and, until this has fallen off or been
removed, any painting over it will be of little value. The
only effectual way of protecting wrought iron is to effect a
thorough and chemical cleansing of the surface of the metal
upon which the paint is to be applied ; that is, it must be
immersed for three or four hours in water containing from
one to two per cent, of sulphuric acid. The metal is after-
ward rinsed in cold water, and, if necessary, scoured with
.sand, put again into the pickle, and then well rinsed. If it
is desired to keep iron a'ready cleansed for a short time before
painting, it is necessary to preserve it in a bath rendered alka-
line by caustic lime, potash, soda, or their carbonates. Treat-
ment with caustic lime water is, however, the cheapest and
most easy method, and iron which has remained in it some
hours will not rust by a slight exposure to dampness. Hav-
ing obtained a clean surface, the question arises, what paint
should be used upon iron ? Bituminous paints, as well as
. those containing variable quantities of lard, were formerly
considered solely available, but their failure was made appar-
ent when the structure to which they were applied happened
to be of magnitude, subjected to great inclemency of weather
or to constant vibration. Recourse has, therefore, been had
to iron oxide itself, and with satisfactory results. A pound
of iron oxide paint, when mixed ready for use in the propor-
tion of two-thirds oxide to one-third linseed oil, with careful
work, should cover twenty-one square yards of sheet-iron,
which is more than is obtained with lead compound.
INVENTOR OF THE SCREW-AUGER.
The screw-auger was invented by Thomas Garrett about
IOO years ago. He lived near Oxford, Chester County, Pa^
The single screw-auger was invented by a Philadelphian, and
it is said to be the only one used with any satisfaction in very
hard woods, where the double screw-augers become clogged
RUST PROOF WRAPPING PAPER.
This is made by sifting on the sheet of pulp, in process of
manufacture, a metallic zinc powder (blue powder), about to
the extent of the weight of the dried paper, the pulp sheet
is afterward pressed and dried by running through the
rolls r.nd over the drying cylinders as' usual. The zinc powder
Hberes to the paper, and 'is partly incorporated with it, the
amount varying with the thickness and wetness of the pulp
sheet. The paper may be sized with glue or starch and then
dusted with the zinc powder, or the powder mny be stirred
into the size and then applied to the surface of the p per.
i.f silver, brass or iron articles are wrapped in paper thus pre-
pared, the affinity of the zinc for the sulphureted hydrogen
Always present in the air), chlorine or acid vapors, will pre-
vent those substances from attacking the articles inclosed in the
;j;iper.
IIIP-BATII IN TWO PIECES.
Fig. i.
Draw the hip-bath
full size, as it would
look when finished,
as in Fig. i. Extend
line /', or the front, to
same height as r, the
highest part of the
tub. Draw line d
parallel with e, or
bottom of tub, until
it intersects c and b.
Strike the half-circle
ff9 and divide into
any number of equal
parts, as I, 2, 3, 4,
etc. (the more lines
the better). For the
points draw lines as
shown in profile.
Set dividers same as
when the circles in
Fig. i were described, and strike the circles g g, and with a
T square draw the perpendicular lines// h h h. Draw the line
/' parallel with the lines h. Take the height^ same as from d
to e, in Fig. i, and mark the line /, Fig. : T)raw lines k k
until they intersect at /. Set dividers at /, and strike the
407
circles m m. Draw line ;/, and, taking it as the center Jin*,
step each way one-fourth of the circumference, in as man?
parts as in profile, I, 2, 3, 4, etc., and draw lines same as in
Fig. i.
Take a pair of dividers, and from the bottom of tub in
profile step on the lines, as from 9 to 9, 8 to 8, etc., making
the line in Fig. 2 equal to the lines in profile, stopping where
the curved line a crosses. A line traced through the dots
will give the pattern, is the foot, which is drawn the same as
the other, with the exception of drawing the lines through.i
A VERY durable black paint for out-of-door work, and for
many other purposes, is made by grinding powdered charcoal
in linseed oil, with sufficient litharge or drier. Thin for use
with boiled linseed oil.
408
TRANSMISSION IN ENGLAND.
According to the London Engineer, a fly-rope apparently
was first used in England in 1863, by Mr. Ramsbottom, for
driving cranes at Crewe. These ropes were ^ inch in diam-
eter when new, of cotton, and weighing \l/2 ounces per foot.
They lasted about eight months, and ran at 3,000 per minute.
The total lengths of the rope were 800 feet, 320 feet and 560
feet. The grooves in the pulley were V-shaped, at an angle
of 30°. The cord was supported every 12 feet or 14 feet by
flat pieces of chilled cast iron. The actual power strain on
\he rope was about 17 pounds, and the ropes were kept tight
by a pull of 109 pounds put on by a jockey pulley. Rope-
geftring is now superseding belting and gearing in cotton
mills. It has long been used in South Wales for driving
helve hammers in tin-plate mills. The ropes are usual. y
about 5^ inches to 6j^ inches in circumference, of hemp.
The diameter of the pulleys shouVl be at least 30 times that
of the rope, and the shafts should not be less than 20 feet
apart. A 6^-inch rope is about equivalent to a leather belt
4 inches wide, running at the same speed — 3,000 feet per
minute. Such a rope will transmit 25 horse-power. The
coefficient of resistance to slipping of a rope in a groove is
about four times that of an equivalent belt.
HEAT-PROOF PAINTS.
Steam pipes, steam chests, boiler fronts, smoke connec-
tions and iron chimneys are often so highly heated that the
paint upon them burns, changes color, blisters and often
flakes off. After long protracted use, under varying circum-
stances, it has been found that a silica-graphite paint is well
adapted to overcome these evils. Nothing but boiled linseed
0/7 it required to thin the paint to the desired consistency for
application, no dryer being necessary. This paint is applied
in the usual manner with an ordinary brush. The color, of
course, is black. But another paint, which admits of some
variety in color, is mixed by making soapstone, in a state of
fine powder, with a quick drying varnish of great tenacity
and hardness. This will give the painted object a seemingly
enamele 1 surface, which is durable, and not affected by heat,
acids, or the action of the atmosphere. When applied to
wood it prevents rotting, and it arrests disintegration when
applied to stone. It is well known that the inside of an iron
ship is much more seve-e'y affected bv corrosion than the
outside, and this paint has proven itself to be a most efficient
protection from inside corrosion. It is light, of fine grain,
409
can be tinted with suitable pigments, spread? easily, and
takes hold of the fiber of the iron or steel quickly and tena-
ciously.
A cheap and effective battery can be made by dissolving
common soap in boiling water and adding to it small amounts
of bran and caustic potash or soda. This mixture, while
warm, is poured in a jar containing a large carbon pole and
an amalgamated zinc rod. When cold the battery "sets"
after the manner of a jelly, and consequently will not readily
evaporate or spill over.
NEW PROCESS FOR WIRE MANUFACTURE.
A machine for cheapening and improving steel or iron
wire has been invented, which is calculated to make a change
in many branches of industry in which iron, steel, copper
and brass wire are used. The invention, which has just been
patented, consists of a series of rolls in a continuous train,
geared with a common driver, each pair of rolls having a
greater sp^ed than the pair preceding it, with an intervening
friction clutch adapted to graduate the speed of the rolls to
the speed of the wire in process of rolling. The entire pro-
cess of manufacturing the smallest-sized wires from rods of
one-half inch is done cold. The new process obviates the
danger of unequal annealing, and of burning in the furnaces,
and the wire is claimed to be more flexible and homogeneous
than that produced by the common processes, and capable of
sustaining greater longitudinal strain. It is, therefore,
specially adapted for screws, nails, cables, pianofortes, and
many other uses, and copper wire made by this process is
claimed to be possessed of greatly increased electrical con-
ductivity.
~T EEPERS USED BY THE WORLD'S RAILROADS.
According to the Moniteur Industrie^ the six principal
railways of France use more than 10,000 wooden sleepers per
day, or 3,650,000 per annum. As a tree of ordinary dimen-
sions will only yield ten sleepers, it will be necessary to cut
down 1,000 trees per day. In the United States the con-
sumption is much greater, amounting to about 15000,000
sleepers per year, which is equivalent to the destruction of
170,000 acres of forest, The annual consumption of sleepers
by the railways of the world is estimated at 40,000,000.
From these figures the rapid progress of disfores'ation will
be understood, and it is certain that the natural growth can-
not keep pace with it.
4io
WEIGHTS OF CAST IRON PIPES.
Weights, per foot, of Cast Iron Pipes in general use,
including Socket and Spigot ends.
Diameter.
Thickness.
Wefeht
per foot.
Diameter.
Thickness
x^cijriii
per loot.
g inches.
»4-Kfncli.
ej4 ii.s.
14 inches
% inch.
138 Ihs.
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POINTS FOR BUILDERS,
BY STEEL SOU ARK.
Never compete with a " botch " if you know he is favored
by the person about to build. He will undercut and beat
you every time.
Favor the man who employs an architect. ''• Under an
honest architect you will have less friction, make more
money, be better satisfied with your work, and give greater
satisfaction to the owner than in working from plans fur-
nished by a nondescript.
In tearing down old -work, be as careful as putting up
new.
Old material should never be destroyed simply because it
is old. .
When putting away old stuff, see that it is protected from
rain and the atmosphere.
It costs about fifteen per cent, extra to work up old ma-
terial, and this fact should be borne in mind, as I have known
several contractors who paid dearly for their " whistle " in
estimating on working up second-hand material.
These remarks apply to woodwork only. In using old
brick, stone, slate and other miscellaneous materials, it is as
well to add double price for working up.
Workmen do not care to handle old material, and justly
so. It is ruinous to tools, painful to handle, and very de-
structive to clothing.
In my experience I always found it pay to advance the
wages of workmen — skilled mechanics — while working up
old material. This encouraged the men and spurred them
to better efforts.
Sash frames, with sash weights, locks and trim complete,
may be taken out of old buildings that are being taken down
and preserved just as good as new by screwing slats and
braces on them, which not only keep the frame square, but
prevent the glass from being broken.
Doors, frames and trims may also be kept in good order
until used, by taking the same precautions as in window
frames.
Old scantlings and joists should have all nails drawn or
hammered i.i before piling away.
Counters, shelving, draws and other store-fittings should be
412
kindly dealt with. They will all be called for sooner *r
later.
Take care of the locks, hinges, bolts, keys, and other hard-
ware. Each individual piece represents money in a greater or
less sum.
Old flooring can seldom be utilized, though I have seen it
used for temporary purposes, such as fencing, covering of
veranda floors, while finishing work on plastering, etc. As
a rule, however, it does not pay to take it up carefully and
preserve it.
Conductor pipes, metallic cornices, and sheet metal work
generally can seldom be made available a second time, though
all is worth caring foi, as some parties may use it in repairs.
Sinks, wash-basins, bath-tubs, traps, heating appliances,
grates, mantels and hearth-stones should be moved with care.
They are always worth money and may be used in many
places as substitutes for more inferior fixings.
Marble mantels require the most careful handling.
Perhaps the most difficult fixtures about a house to adapt a
second time are the stairs. Yet, I have known where a
shrewd contractor has so managed to put up new building's
that the old stairs taken from another building just suited.
This may have been a " favorable accident," but the initiated
reader will understand him. Seldom such accidents can
occur.
Rails, balusters and newels may be utilized much readier
than stairs, as the rail may be lengthened or shortened to ~;uit
variable conditions.
Gas fixtures should be cared for and stowed away in some
dry place. They can often be made available, and are easily
renovated if soiled or tarnished.
It is not wise to employ men to take down buildings who
who have no other qualities to recommend them than their
strength. As a rule they are like bears — have more strength
than knowledge, and the lack of the latter is often an ex-
pensive desideratum. Employ fcr taking down the work
good, careful mechanics, and do not have the work " rushed
through." Rushers of this sort are expensive.
Never send old material to a mill to be sawed or planed.
No matter how carefully nails, pebbles and sand have been
hunted for, the saw or planer knives will most assuredly
find some you overlooked; then there will be trouble at the
mill.
Have some mercy for the workman's tools. If it can be
avoided, do not work up old stuff into fine work. If not
413
avoidable, pay the workman something extra because of in*
jury to tools.
Don't grumble if you do not get as good results from the
use of old material as from new. The workman has much
to contend with' while working up old, nail-speckled, sand-
covered material.
RULES FOR ESTIMATING COST OF PLASTER.
ING AND STUCCO WORK.
PLASTERING.
Plastering is always measured by the square yard for aV
plain work, and by the foot superficial for all cornices of
plain members, and by foot lineal for enriched or carved
moldings in cornices.
By plain work is meant straight surfaces (like ordinary
walls and ceilings), without regard to the style or quantity of
finish put upon the job. Any paneled work, whether on
walls or ceilings, run with a mold, would be rated by the
foot superficial.
Different methods of valuing plastering find favor in
different portions of the country. The following general
rules are believed to be equitable and just to all parties:
Rule i. — Measure on walls and ceilings the surface
actually plastered without deducting any grounds or any
openings of less extent than seven superficial yards.
Rule 2. — Returns of chimney breasts, pilasters and all
strips of plastering, less than 12 inches in width, measure as
12 inches wide; and where the plastering is finished down
upon the wash-board, surbase or wainscoting, add 6 inches to
height of wall.
Rule 3. — In closets, add one-half to the measurement ;
01, if shelves are put up before plastering, charge double
measurement. Raking ceilings and soffits of stairs, add one-
half to the measurement. Circular or elliptical work, charge
two prices ; domes or groined ceilings, three prices.
Rule 4. — For each 12 feet interior work is done further
from the ground than the first 12 feet, add five per cent.
For outside work, add one per cent, for each foot the work
is done above the first 12 feet.
STUCCO WORK.
Rule i. — All moldings, less than one foot girt, to be
rated as one foot ; over one foot, to be taken superficial.
When work requires two molds to run same cornice, add
one-fifth.
4H
Rule 2. — For each internal angle or miter, add one foot
to length of cornice ; and each external angle add two feet.
All small sections of cornice less than 12 inches long measure
as 12 inches. For raking cornices add one-half. Circular or
elliptical work, double price ; domes and groins, three prices.
Rule j. — For enrichments of all kinds, charge an agreed
price.
Rule 4. — For each 12 feet above the first 12 feet from
the ground, add five per cent.
CHINESE CASH.
A large number are engaged in molding, casting and fin-
ishing the "cash" used as .coin all over China, Mexican
dollars and Sycee silver being used in large transactions. The
cash are made from an alloy of copper and zinc, nearly
the same as the well-known Munn metal, and it takes
about 1,000 of them to answer as change for a dollar, so
minute and low do prices run in this country, of which 1 will
only give one instance. The fare for crossing the ferry on the
Peiho was only two cash, or one-fifth of a cent.
DEEP SOUNDINGS NEAR THE FRIENDLY
ISLANDS.
Her Majesty's surveying ship Egeria, under the com-
k»...nd of Captain P. Aldrich, R. N., has, during a recent
sounding cruise and search for reported banks to the south of
the Friendly Islands, obtained two very deep soundings of
4,295 fathoms and 4,430 fathoms, equal to five Eng-
lish miles respectively, the latter in latitude ^4 deg.
37 min. S., longitude 175 deg. 8 min. W. , ;e other
about twelve miles to the southward. The/ .* depths
are more than 1,000 fathoms greater than • y before
obtained in the Southern Hemisphere, ant-' are only
surpassed, as far as is yet known, in three spots in the
the world — one of 4,655 fathoms off the northeast coast of
Japan, found by the United States steamship Tuscarora ;
one of 4,475 fathoms south of the Ladrone Islands by the
Challenger; and one of 4,561 north of Porto Rico, by the
United States ship Blake. Captain Aldrich's soundings
were obtained with a Lucas sounding machine and galvan-
ized wire. The deeper one occupied three hours, and
was obtained in a considerably confused sea, a specimei)
of the bottom being successfully recovered. Temperature
of the bottom, 33.7 deg. Fahr.
415
SIZE AND WEIGHT OF FLAT-TOP CANS.
The following table gives the size of the flat top cans and
the amount of material required when galvanized iron is used
in their construction. The table shows the net weight per
can with iron from No. 27 gauge to No. 20 gauge. No al-
lowance is made for seams, hoops, or solder.
SIZE CANS.
WEIGHT 1'ER CAN.
No.
No.
No.
No.
No.
No.
No.
N-
27 G.
26 G.
25 G.
24 G.
230.
22 G.
" G>* ^
O
6
g i
.S*|
Height
Inches.
3 5
3 o
* ,1 ~ ""
3 3
3 o
_Q N
H-3 O
3 o-
*, 6"
3 o
i
6*/4
*K
i 6
i 7
2
%Vz
8^
2 2
2 4
3
9
11^
2 I3
3 o
5
i°/^
13%:
3 13
4 2
4 6
4 14
5 7
5 J5
6 9
7 6
5
nK
ijK
3 13
4 2
4 6
4 Hi 5 7
5 15
6 9
7 6
6
ii^
13!^
4 3
4 8
4 12
5 6
5 J5
6 9
7 2
8 i
8
13*
13^
5 4
5 *o
6 o
6 12
7 8
8 9
9
IO I
10
13^2
165^
6 o
6 7
6 14
7 12
8 9
9 7
10 5
ii 9
15
lsK
9
7 is| 8 8
9 i
10 3
IT 5
12 7
13 9
15 4
20
IIIA
igl/2,
9 8|io 2
10 13
12 3
13 8
14 4
16 3
18 4
20
25
16
18
23
9 8|io 2 10 13
12 3
13 8
14 4
16 3 18 4
30
26^
12 10
13 8 14 7
16 4
18 o
J9 X3
21 IO 23 II
35
181^ y>Y>
14 o 15 o 1 6 o
18 o
20 o
22 0
24 o 27 o
40
18^34 "
15 9
16 10
17 ii
19 is
22 2
24 6
26 9 29 14
45
19^135
16 10
17 13
19 o 21 6
23 12
26 2
28 8 32 i
So
20^ 35
17 ii
l8 15 20 3 22 12
25 4
27 I3
30 5
34 2
55 21%
36
18 14
20 6 21 10 24 3
26 7
29 12
32 736 8
6022
6522^
38
20 3
21 3
21 IO 23 O
22 9 24 3
25 15
27 4
28 12
30 5
31 IO
33 6
34 8
36 5
38 13
40 14
7023
40
22 IO 24 4 25 13
29 i
32 5
35 8
38 12
43 9
75 23 1A 40
23 ' 3
24 14 26 9 29 13 33 2
36 7
39 i3
44 J3
8024^
8525
40
40
24 7
25 i
26 3
26 14
27 15 31 7
28 10 32 7
34 J5
35 13
38 6
39 6
4i 15
43 °
47 3
48 5
9024^
45
26 13
28 ii
30 10
34 7
38 4
42 i
45 i5
95 25
45
27 7
29 6
31 5
35 4
39 3
43 i
47 o 52 14
100 26
45
28 13
30 14
32 14
37 o
41 2
45 4
49 6(55 9
I25 27^
50
33 8
35 i5
38 5
43 2
47 M
52 ii
57 7,64 I0
150 29
52^
37 i
39 12
42 6
47 ii
52 15
58 4
63 9! 71 9
J75 3°
20030%;
64 2
41 9
46 6
44 8
49 12
47 7
53 3
53 6
59 J4
59 5
66 6
65 3
71 380 I
79 10:89 10
Mexican coal has been successfully used for making coke
at Pittsburg.
THE CHICAGO AUDITORIUM.
At a meeting of the Chicago Auditorium Association the
president submitted his report, from which we take the fol-
lowing:
To the Stockholders of the Chicago Auditorium Associa-
tion— Your great undertaking has progressed to a point when
a recital of the condition of affairs, together with a brief his-
tory of the project, will be of especial interest to you.
Ground was broken and the work of tearing down build-
ings was begun in January, 1887. The constvuction has bee*
vigorously prosecuted from that time, the only delay occur-
ring from difficulty in procuring granite, which necessitated
the association taking possession of the quarries, the result of
which was satisfactory. From the date of completion of the
granite work, comprising the two stories of the sub-structure,
all contracts have been thus far satisfactorily and promptly
carried forward, and we feel that we have been exceptionally
fortunate in the selection of all the contractors, especially so
of the architects, who have faced most difficult and unprece-
dented problems.
This enterprise, like all large projects, has been a matter
ot growth and development from its inception, both in mag-
nitude and cost, and, in the judgment of your board, it has
been in every instance wise. It was originally contemplated
by the projectors that a great public hall and a hotel should
be built on a site not including the corner of W abash avenue
and Congress street and the north lot of the Michigan avenue
frontage, which were not then obtainable. From that your
building has grown to cover the entire site now occupied —
710 feet frontage, or an area of one and five-eighths acres.
Strict fire-proof construction of the most approved kind was
always contemplated, and it prevails throughout the entire
structure ; so that under no circumstances can your building
sustain more than slight superficial injury from fire. The
tenth story has recently been changed to make it one foot
higher, and one story has been added to the plans of the
tower this summer.
With the grandeur of the rising building developed the
necessity of absolutely first-class treatment in details and
interior finish. The hotel rooms will be finished in hard-
wood throughout ; mosaic floors will be laid in the vestibule
and lobby in the Auditorium and hotel. The grand stair-
way will be marble, writh bronze sides. An extra elevator
was recently decided upon, making twelve in all, nine passen-
ger and three freight.
4*7
A grand organ, costing about $50,000, was contracted
for, and is being built probably at a loss to the contractor,
the contract for which calls for the most complete and
grandest instrument ever constructed, and which your board
believes will do much for musical education in this city, and
add largely to the earnings of your Auditorium — more than
ordinary interest on its cost.
It was also determined to adopt the most approved and
modern stage, with appointments similar to one at Buda-
Pesth, Hungary, for which purpose Architect Adler was sent
to Europe, and Mr. Bairstow, chief stage carpenter for
McVicker's theater for many years, was employed, and
accompanied him abroad. This will cost much more than
the ordinary stage, but will be unequaled on either continent
in its effects and operating economies, and it is regarded a
judicious step by your board, as it constitutes, in theatre
parlance, a permanent attraction.
Then there are the devices of heavy ironwork for shutting
off the galleries and part of the main balcony, lessening the
cubic contents of our hall, thereby adapting it for many pur-
poses for which otherwise it could not well be used. This
nas added considerably to cost of ironwork.
A few statistics respecting your structure, about which so
many questions are asked, may be of interest to you. It com-
prises five principal features — the auditorium, with its grand
organ and stage; the hotel; the business front on Wabash
avenue, containing seven stories and nine floors of rooms; the
fettle' auditorium, or rehearsal hall; and the public observa-
tory. To which might be added the cafe cm the main floor
on Congress street. The main building will be ten stories
high, or 145 feet, the auditorium proper reaching the seventh
story. The tower will be seventeen stories high, or 240 feet.
The foundations under your buildings have been carefully and
scientifically considered. Every square yard of the ground
was first tested by heavy water-tanks, then horizontal tim-
bers of varying lengths, one square, were laid permanently
below the water-line, covering whi h is a heavy bed of con-
crete, in which from one to four layers of 67-pound steel
rails are imbedded. These, if placed in line, would reach ten
miles in length. Where the rails were insufficient in strength,
steel I-beams were substituted for them. Upon these rails
and beams the piers were constructed. The tower rests on
a solid foundation, 100x67 feet, thus distributing the weight
over a larger surface. The auditorium will contain 5,000 seats,
including forty-two boxes. This capacity can be largely
increased for conventions by utilizing the stage space. The
418
hotel will occupy the entire Michigan avenue and congress
street fronts, and forty feet of Wabash avenue front, and
will contain nearly 400 rooms. The main dining-room will
be on the tenth floor of the east front, 175 feet long, over-
looking the lake. There will be twelve elevators in all.
The cost of the iron in the building is nearly $350,000, no
portion of which will be visible. The number of brinks in
the building is 15,000,000.
The number of electric lights in the auditorium proper
is 4,000; in the hotel and balance of the building, 4,600;
making 8,600 in all. The electric current is generated by
eleven dynamos and nine engines ; there will be eleven
boilers, having a capacity of 1,800 horse-power; and
twenty-one pumping engines to supply water fur the
elevators and other purposes, with a total hourly capacity of
400,000 gallons. There are two distinct heating and lighting
plants for the hotel and balance of building. The tower
weighs 30,000,000 pounds, or 15.000 tons. There are over
twenty-five miles of gas and water pipes.
To calculate number of shingles for a roof, ascertain num-
ber of square feet and multiply by 4; if 2 inches to weather,
8 for 4^ inches, and 7 1-5 if 5 inches are exposed. The
length of rafter of one third pitch is equal to three-fifths of
width of building, adding projection.
PAINTWORK.
Tt may be useful to know that a gallon of paint will cover
from 450 to 630 superficial feet of wood. On a well-painted
surface of iron the gallon will cover 720 feet. In estimating
painting to old work, the first thing to do is to find out the
nature of the surface, whether it is porous, rough ot smooth,
hard or soft. The surface of stucco, for example, will take a
great deal more paint than on of wood, much depending on
the circumstance whether it has been painted, and what state
the surface is in. We have known prices tendered for outside
painting that have been seriously wrong, owing to the want
of knowing the condition of the stucco work. A correct e Mi-
niate of repainting woodwork cannot be made from the quan-
tities only; a personal examination ought to be made in every
tase where there is much work to be done. A great many
painters trust to the quantity; the consequence is, nothing is
allowed to remove old paint, or for scouring, and the stopping
of cracks.
Then, there is painting and painting. It can be done well
and artistically, or indifferently, and few trades allow of
greater scamping. In first-class work, after the first two coats
419
have been put on, the paint, when dry, should be rubbed
down with pumice-stone before the finishing coats are put on.
Inferior painting is so common that it has « fj.emoralizing effect
on painters of the day. The quality of tue material, especially
the white lead, has much to do with the permanency. We
find painting done on old work without any cleaning, stopping
or even pumicing. A slovenly and inartistic class of Drainers
are also met with, who repaint and '-e^rain on work that
ought to bi well rubbed with pumice-sione or sand-paper be-
fore the first new coat is laid.
For painting three coats the following materials are given
for ioo superficial feet of ne\v work: Paint, eight pounds;
boiled linseed oil, three pints; spirits of turpentine, one ] int;
the work taking thre men for one clay. According (o Saxton,
forty-five yards of first coat, including stopping, will require
five pounds of white lead, five pounds of putty, one quart of
oil. The same quantity of each succeeding coat will require
the same allowance of white lead and oil. The best materials
will last for seven years, but the ordinary painting seldom lasts
three.
THE ANNUAL KING IX TREES.
The annual rings in trees exist as such in all timber grown
in the temperate zone. Their structure is so different in
different groups of timber that, from their appearance alone,
the quality of the timber may be judged to some extent.
For this purpose the absolute width of the rings, the regu-
larity in width from year to year and the proportion of spring
wood to autumn wood must be taken into account. Spring
wood is characterized by less substantial elements, the ves-
sels of thin-walled cells being in greater abundance, while
autumn wood is formed of cells with thicker walls, which
appear darker in color. In conifers and deciduous trees the
annual rings are very distinct, while in trees like the birch,
linden and maple the distinction is not so marked, because
the vessels are more evenly distributed. Sometimes the
gradual change in appearance of the annual ring from spring
to autumn wood, which is due to the difference in its compo-
nent elements, is interrupted in such a manner that a more or
less pronounced layer of autumn wood can apparently be
recognized, which again gradually changes to spring or sum-
mer wood, and then gradually finishes with the regular autumn
wood. r\ his irregularity may occur even more than once .,i
the same ring, and this has led to the notion that the annual
rings are not a true indication of age; but the double or
42°
counterfeit tings can be distinguished by a practiced eye with
the aid of a magnifying glass. These irregularities are due
to some interruptions of the functions of the tree, caused by
defoliation, extreme climatic condition or sudden changes of
temperature. The breadth of the ring depends on the length
of the period of vegetation; also when the soil is deep and rich,
and light has much influence on the tree, the rings will be
broader. The amount of light, and the consequent development
of foliage, is perhaps the most powerful factor in wood forma-
tions, and it is upon the proper use of this that the forester
depends for his means of regulating the development and
quantity of his crop.
POINTERS FOR ARCHITECTS, BUILDERS AND
WOOD-WORKERS.
A box of window-glass contains fifty feet of glass, regard-
less of size of sheets.
African teak-wood outlasts any other kind of wood. It
is the only wood found preserved in Egyptian tombs 4,0x30
years old. It shrinks only " on end. "
It is a common practice in France to coat the beams, the
joists and the under side of the flooring of buildings with a
thick coating of lime- wash as a safeguard against fire. It is
a preventive of prime ignition, although it will not check a
fire when once under headway.
Any beam, whether of wood or iron, is as much stronger
when placed on its edge as when on its side, as the width is
greater than he thickness. Thus a stick or bar of iron one
inch by three inches when used as abeam is three limes as
strong when placed on its edge as when on its side. This is
true only within limits. It would not be true of a piece of
boiler-plate, on account of the flexibility.
Mortar made in the following manner will stand if used in
almost all sorts of weather : One bushel of unslaked lime,
three bushels of sharp sand ; mix I Ib. of alum with one pint
of linseed oil, and thoroughly mix this with the mortar when
making it, and use hot. The alum will counteract the action
of the frost on the mortar.
A new system of building houses of steel plates is being
introduced by M. Danly, manager of the Societe des Forges
de Chateleneau It has been found that corrugated sheets
only a millimetre in thickness are sufficiently strong for build-
ing houses several stories high, and the material used allows
of architectural ornamentation. The plates used are of the
42I
finest quality, and as they are galvanized after they have been
cut to the sizes and shapes required, no portion is left
exposed to the action of the atmosphere. Houses so con-
structed are very sanitary, and the necessary ventilating and
heating arrangements can readily be carried out.
Moisture-proof glue is made by dissolving 16 ounces of
glue in 3 pints of skim milk. If a still st ronger glue be want-
ed, add powdered lime.
Shellac and borax boiled in water produces a good stain
for floors.
Don't inclose the sink — no place in a kitchen is so
much neglected.
Porch floors should be of narrow stuff and the joints laid
in white lead.
Lime-water is fire-proof protection for shingles or any
light wood-work.
Common brick absorb a pint of water each, and make a
very damp house.
The lowest -priced builder is not always the cheapest, as-
poor work will testify.
A closet finished with red cedar shelves and drawers is
death to moths and insects.
Do not locate a furnace register next to a mantel — that
is, if you wish to utilize the heat.
Terra-cotta flue linings are a great improvement over
the old, roughly plastered chimney.
For basement fl >oring, oak is preferred to maple because
it will stand dampness better.
To properly select the colors applicable to the proper
place, consult an educated painter
A ventilating flue from the kitchen into the chimney
often does away with atmospheric meals.
Stops to doors and windows should be fastened with
roundhead screws, so as to be easily moved.
It is better to oil floors than to paint them — a monthly
rubbing will make them as good as new.
Do not use one chimney-flue for two stove pipes — the
draft of one will counteract that of the other.
Do not finish windows to the floor — -the circulation
across the floor is one of the causes of cold houses.
Ash-pits in cellars under fire-places and mantels save
taking up ashes, for they may be raked down through a hop-
per.
Do not construct solid doors of two kinds of hardwood
— the action of the atmosphere on one or the other will
cause the door to warp.
422
HINTS ON VENTILATION.
In ventilating — say, a bed-room — by means of the win-
dow, what you may principally \\ant is an upward-blowing
current. Well, there are several methods of securing this
without danger of a draught.
1. Holes may be bored in the lower part of the upper
sash of the window, admitting the outside air.
2. Right across one foot of the lower .-a h. but attached
to the immovable frame of the wind >v. , may he hung or tacked
apiece of strong Willesdeu paper— prettily painte I \\ith
flowers or birds, if you please. The window may then he
raised to the extent of the breadth of this ] aner, ; ml the air
rushes upward between the two sashes.
3. The same effect i; goc from simply having a b:>ard
about six inches \vide and the exact si/.e of the sash's ! readth.
Use this to hold the window up.
4. This same board may have two bent or elbow tubes in
it, opening upward and into the room, so that the air
coming through does not blow directly in. The inside open-
ings may be protected by valves, and thus tlv> amount of in-
coming current can be regu'ated. We thus get a circulating
movement of the air, as, the window being raised, there is an
opening between the sashes.
^ 5. In summer a frame half as big as the lower <-ash may
be made of perforated zinc or wire gau/.e and placed in so as
to keep the window up. There is n > draught ; and, if kept in
position all night, then, as a rule, the inmate wi'.l enjoy re-
freshing sleep.
6. In addition to these plans, the door of every bed-
room should possess, at the top thereof, a ventilating panel,
the simplest of all being that formed of wire gauze.
In conclusion, let me again beg of you t"> value fresh air
as you value life and health itself; while taking care not to
sleep directly in an appreciable draught, to abjure curtains
all round the bed. A curtained bed is only a stable for
nightmares and an hotel for a hundred wonder-ills and ail-
INVENTION OF THE SCREW AUGER.
Tiie screw auger was invented by Tl omas Garrett anout
100 years ago. He lived near Oxford, Chester County,
Pennsylvania. The single screw auger was invented by a
Philadelphia!!, and it is said to be the only one used with any
Satisfaction in very hard woods where the double screw augers
become clogged.
423
THE FORESTS OF THE UNITED STATES.
The total area of forest lands in the United States and
Territories, according to the annual report of the Division
of Forestry of the Department of Agriculture, is 465,795,000
acres. The State which has the largest share is Texas,
which is credited with 40,000,000 acres. Minnesota comes
next with 30,000,000, then Arkansas with 28,000,000; and
Florida, Oregon, California and Washington Territory are
put down at 20,000,000 each. Georgia and North Carolina
nave each 18,000,000; Wisconsin and Alabama, each
17,000,000; Tennessee, 16,000,000; Michigan, 14,000,000;
and Maine, 12,000,000 acres. Taking the States in groups,
the six New England States have, in round numbers,
19,000,000 acres; four Middle States, 18,000,000; nine
Western States, iVo,ooo.ooo; four Pacific States, 53,000,000;
seven Territories, 63.000,000; and fourteen Southern States,
233,000,000 acres, or almost precisely half of the whole for-
est area of the country.
Reviewing the figures given by the department, the
Tradesman, of Chattanooga, Tenn., makes the following
instructive comment: " These statistics show that, while the
process of denudation has been carried on to an unhealthy
extreme in the Eastern, Middle and a few of the Western
States, the forest area still remaining in this country is a
magnificent one. If the estimates of the department are
approximately correct, the timber lands of the country,
exclusive of Alaska, cover an area equal to fifteen States the
size of Pennsylvania. If proper measures are taken to pre-
vent the rapid and unnecessary destruction of what is left of
our forest domain, it should be equal to all requirements for
an indefinite period. It is not yet a case of locking the
stable after the horse is stolen, and never should be allowed
to become so. With the adoption the policy of judicious
trfee planting in the prairie States, and a system of State or
government reservations in the mountainous districts, which
are the sources of the chief rivers of the country, the evil
effects which have followed forest denudation in Europe and
some portions of Asia would never exist here."
TO FIND THE WEIGHT OF GRINDSTONES.
.06363 times square of inches diameter, times thickness
in inches = weight of grindstone in Ibs.
3.1415926--- ratio of diameter to circumfeieuce of circle.
424
ALTITUDE ABOVE THE SEA-LEVEL OF VARI-
OUS PLACES IN THE UNITED STATES.
Portland, Me . .
185
Knoxville, Xenn ....
Concord, N H
• • • 375
Louisville, Ky
'
Cleveland, O
645
480
Detroit Mich
Upper portion of city
t-88
Mt. Washington
Ann Arbor Mich. ..
.... 6,2Q3
800
San Francisco, Cal
Indianapolis, Ind ....
130
Boston, Mass
82
Chicago, 111
r«T
Albany, N. Y
CQQ
New York N Y
60
St Anthony Falls Minn
822
Buffalo N Y
580
Dubuque la
Philadelphia Penn . . .
60
St Louis Mo
/l80
Pittsburg Penn
QT tr
Omaha Neb
Baltimore, Md
• • • 275
Lawrence Kan.
SO-!
Washington,!). C....
. . . 92
Fort Phil Kearney Wy
6 ooo
Charleston, S. C
Yankton, Dak
Vicksburg, Miss
352
Fort Garland, Colo
8 365
New Orleans, La
El Paso, Texas
10
•• 3,831
Salt Lake City, Utah
Sacramento, Cal
4,322
22
TABLE OF PRINCIPAL ALLOYS.
A combination of zinc and copper makes bell metal.
A combination of copper and tin makes bronze metal.
A combination of antimony, tin, copper and bismuth, makes britannia
metal.
A combination of copper and tin makes cannon metal.
A combination of copper and zinc makes Dutch gold.
A combination of copper, nickel and zinc, with sometimes a little iron
and tin, makes German silver.
A combination of -gold and copper makes standard gold.
A combination of gold, copper and silver, makes old standard gold.
A combination of tin and copper makes gun m >tal.
A combination of copper and zinc makes mosaic gold.
A combination of tin and lead makes pewter.
A combination of lead and a little arsenic, makes sheet metal.
A combination of silver and copper makes standard silver.
A combination of tin and lead makes solder.
A combination of lead and antimony makes type metal.
A combination ot copper and arsenic makes white copper.
HOW TO POLISH ZINC.
AVe have been successful in polishing zinc with the follow-
ing solution : To 2 quarts of rainwater add 3 oz. powdered
rotten stone, 2 oz. pumice stone, and 4 oz. oxalic acid. Mix
thoroughly, and let it stand a day or two before using. Stir
or shake it up when using, and, after using, polish the zinc
with a dry woolen cloth or chamois skin. The more thor-
oughly the zinc is rubbed the longer it will stay bright.
425
HOW TO MAKE A GOOD FLOOR.
Nothing attracts the attention of a person wishing to rent
or purchase a dwelling, store or office, so quickly as q, hand-
some, well-laid floor, and a few suggestions on the subject,
though not new, may not be out of place.
The best floor for the least money can be made of yellow-
pine, if the mateiial is carefully selected and properly laid.
First, select edge-grain yellow pine, not too "fat," clear
of pitch, knots, sap and splits. See that it is thoroughly
seasoned, and that the tongues and grooves exactly match, so-
that, when laid, the upper surfaces of each board are on a
level. 1'his is an important feature often overlooked, and
planing-mill operatives frequently get careless in adjusting
the tonguing and grooving bits. If the edge of a flooring
board, especially the grooved edge, is higher than the edge
of the next board, no amount of mechanical ingenuity can
make a neat floor of them. The upper part of the groove
will continue to curl upward as long as the floor lasts.
Supposing, of course, the sleepers, or joists, are properly
placed the right distance apart, and their upper edges pre-
cisely on a level, and securely braced, the most important
part of the job is to " lay " the flooring correctly % This
part of- the work is never, or very rarely ever, done nowa-
days. The system in vogue with carpenters of this day, of
laying one board at a time, and " blind nailing," is the most
glaring fraud practiced in any trade. They drive the tongue
of the board into the groove of the preceding one, by
pounding on the grooved edge with a naked hammer, mak-
ing indentations that let in the cold air or noxious gases, if
it is a bottom floor, and then nail it in place by driving a
six-penny nail at an angle of about 50° in the groove. An
awkward blow or two chips off the upper part of the groove,
and the last blow, designed to sink the nail-head out of the
way of the next tongue, splits the lower part of the groove
to splinters, leaving an unsightly opening. Such nailing
does not fasten the flooring to the sleepers, and the slanting
nails very often wedge the board up so that it does not bear
on the sleeper. We would rather have our flooring in the
tree standing in the woods than put down that way.
The proper plan is to begin on one side of the room, lay
one course of boards with ihe tongue next to, and neatly
fitted to, the wall (cr studding, if a frame house), and be
sure the boards are laid perfectly straight from end to end
of the room and square with the wall. Then nail this course
firmly to the sleepers, through and through, one nail near
426
each edge of the board on every sleeper, and you are ready-
to begin to lay a floor. Next, fit the ends and lay down
four or six courses of boards (owing to their width). If the
boards differ widely in color, as is often the case in pine, do
not lay two of a widely different color side by side, but
arrange them so that the deep colors will tone off into the
lighter ones gradually. Push the tongues into the grooves
as close as possible, without pounding with a hammer, or, if
pounding is necessary, take a narrow, short piece of flooring,
put the tongue in the groove of the outer board, and pound
gently on the piece, never on the flooring board. Next,
adjust your clamps on every third sleeper and at every end
joint, and drive the floor (irmly together by means of
wedges. IDrive the wedges gently at the start, and each one
equally till the joints ail fill up snugly, and then stop, for, if
driven too tight, the fl >or will spring up. Never wedge
directly against the edge of the flooring board, but have a
short strip with a tongue on it between the wedge and the .
board, so as to leave no bruises. Then fasten the floor to
the sleepers by driving a flat- headed steel wire nail of suit-
able size, one inch from either edge of every board, straight
do\Mi into each sleeper. At the end-joints smaller nails may
be used, two nails in board near the edges, and as far from
the ends as the thickness of the sleeper will permit. Pro-
ceed in this manner until the floor is completed, and you
will have a floor that will remain ti^ht and look well until
worn out.
Such minute directions, for so common and simple a job,
sound silly, but are justifiable from the fact that there are so
many alleged carpenters who either do not know how or are
too lazy to lay a floor properly.
GLUE FOR DAMP PLACES.
For a strong glue, which will hold in a damp place, the
following recipe works well : Take of the best and strongest
glue enough to make a pint when melted. Soak this until
soft. Pour off the Mater, as in ordinary glue-making, and
add a little \\ater if the glue is likely to be too thick. When
melted, add three table-spoonfuls of boiled Unseed oil. Stir
frequently, and keep up the heat till the oil disappears,
which may take the whole day, and perhaps more. If
necessary, add water to make up for that lost by evaporation.
When no more oil is seen, a tablespoonful of whiting is added
and thoroughly incorporated with the glue.
427
MORTAR MAKING. ^
Much depends on having mortar made on correct, if not
scientific, principles. The durability, if not the actual safety,
of a building is more or less affected by the kind of mortar
that is put into it. We have seen brick buildings, and not
very old ones either, from which the dry and hardened mor-
tar could easily be picked in cakes from between the bricks.
The advantage of using such mortar is, that, when the
building tumbles down, ^ there will be no trouble in picking
from it the old bricks, preparatory to rebuilding. A brick
wall, if put up with the right kind of mortar, will be solid
and almost homogeneous, as likely to break through the
middle of the bricks as at the joints. Such a building will
never tumble down, except under great strain, and will with-
stand a pretty severe earthquake shock.
An old builder, of nearly forty years' experience in mak-
ing mortar, writing upon the subject to a contemporary,
very justly says: "The mere matter of slacking lime does
not make mortar out of it. Lime and water alone will not
make any better mortar than sand and water." t He sug-
gests the use of plenty of water in slacking the lime, so
that, when it is run out of the box into the bed, it will not
bake or burn, as it is liable to do, if not well watered. The
mortar bed should be large and tight, so there will be no
leakage of the lime water. The proportion should be
about fifty yards of good sand to twenty-five barrels of lime,
for the first mixing, which should be thoroughly done. The
hair should be put into the lime before mixing in the sand.
After the mortar has been mixed in the above proportions
for ten clays or more, if the amount of materials given have
been used, twenty-five to fifty loads of sand may be added
and worked in. It is said that the water that rises on a
bushel of slaked lime, and where plenty of water has been
used, if removed and put on a sharp sand, will make better
stone than lime and sand mixed, showing that the water
should be retained in the sand and lime while it is fresh, and
that the mortar should be tempered in its own liquor. Of
course, where smaller quantities are used, the proportion
should be retained, both at the first mixing and in the sand
added subsequently,
A pound of ten-p«nny cut nails will do as much work as
two pounds of wire nails. Taking the average of all cut nails,
they are worth nearly double as much as wire nails, from
tests made at the Watertown Government Arsenal.
428
COST OF EXCAVATING AND HANDLING ROCK.
The average weight of a cubic yard of sandstone or con-
glomerate, in place, is given as 1.8 tons, and of compact
granite, gneiss, limestone or marble, 2 tons, or an average of
1.9 tons, or 4,256 pounds. A cubic yard, when broken up
ready for removal, increases about four-fifths in bulk, and
f~i of a cubic yard, 177 pounds, is a wheelbarrow load.
Experience shows that, with wages at $i per day of 10
hours, 45 cents per cubic yard is a sufficient allowance for
loosening hard rock. Soft shales and allied rocks may be
loosened by pick and plow at a cost of 20 cents to 30 cents
per cubic yard. The quarrying of ordinary hard rock re-
quires from % pound to ^ pound and sometimes *4 pound
of powder per cubic yard. Drilling with a churn driller
costs from 12 to iScenis per foot of hole bored. Upon
these data, Mr. Rigly estimates the total cost, per cubic
yard of rock in place, for loosening and removing by wheel-
barrow (labor assumed at $i per day of 10 hours), as fol-
lows: When distance removed is 25 feet, total cost=$o. 537;
when 50 feet, $0.549; when 100 feet, $0.573; when 2OO<eet,
$0.622; when 500 feet, $0.768; when 1,000 feet, $1.011; and
when i, 800 feet, $1.401. This is exclusive of Contractor's
profit. ^
When labor is $1.25 per day, add 25 per cent, to the cost
prices given; when $1.50 per day, add 50 per cent, and so
on. In hauling by cart, the cost of loading, which will be
about 8 cents per cubic yard of rock in place, and the addi-
tional expense of maintaining the road must be added.
Allowing, then, 851 pounds as a cart-load, the total cost per
cubic yard is estimated, when removed 25 feet, at $0.596;
when 50 feet, $0.599; when 100 feet, $0.605; when 200 feet,
$0.617; when 500 feet, $0.655; when 1,000 feet, $0.717; and
when j, 800 feet, $0.94.
IRON BRICK.
It is reported that the German Government testing labor-
atory for building materials has reported favorably on a new
paving-block called iron brick. This brick is made by mix-
ing equal parts of finely-ground clay, and adding 5 per cent,
of iron ore. This mixture is moistened with a solution of 25
per cent, sulphate of iron, to which fine iron ore is added
until it shows a consistency of 38 degrees Baume. It is then
formed in a press, dried, dipped once more in a nearly con-
centrated solution of sulphate of iron and finely ground iron
ore, and is baked in an oven for 48 hours in an oxidizing
flame, and 24 hours in a reducing flame-
429
DRY ROT IN TIMBER.
No wood which is liable to damp, or has at any time
absorbed moisture, and is in contact with stagnant air, so
that the moisture cannot evaporate, can be considered safe
from the attack of dry rot.
Any impervious substance applied to wood, which is not
thoroughly dry, tends to engender decay ; floors covered
with kamptulicon and laid over brick arching before the
latter was dry ; cement dado to wood partition, the water
expelled from dado in setting, and absorbed by the wood,
had no means of evaporation.
Woodwork coated with paint or tar before thoroughly
dry and well seasoned, is liable to decay, as the moisture is
imprisoned.
Skirtings and wall paneling very subject to dry rot, and
especially window backs, for the space between woodwork
and the wall is occupied by stagnant air ; the former absorbs
moisture from the wall (especially if it has been fixed before
the wall was dry after building), and the paint or varnish
prevents the moisture from evaporating into the room.
Skirting, etc., thus form excellent channels for the spread of
the fungus. ^
Plaster seems to be sufficiently porous to allow the
evaporation of water through it ; hence, probably, the space
between ceiling and floor is not so frequently attacked, if
also the floor boards do not fit very accurately and no oil
cloth covers the floor.
Plowed and tongue floors are disadvantageous in cer-
tain circumstances, as when placed over a space occupied
by damp air, as they allow no air to pass between the boards,
and so dry them.
Beams may appear sound externally and be rotten
within, for the outside, being in contact with the air,
becomes dryer than the interior. It is well, therefore, to
saw and reverse all large scantling.
The ends of all timber, and especially of large beams,
should be free (for it is through the ends that moisture
chiefly evaporates). They should on no account be imbed-
ded in mortar.
Inferior and ill-seasoned timber is evidently to be
avoided. *
Whatever insures dampness and lack of evaporation is
conducive to dry-rot, that is to say, dampness arising from
the soil ; dampness arising from walls, especially if the
damp-proof course has been omitted ; dampness arising
430
from use of salt sand ; dampness arising from drying of mor-
tar and cement.
Stagnation of air resulting from air grids get ting blocked
with dirt or being purposely blocked through ignorance.
Stagnation may exist under a floor although there are grids
in the opposite walls, for it is difficult to induce the air to
move in a horizontal- direction without some special means
of suction. Corners of stagnant air are to be guarded
against.
Darkness assists the development of fungus ; whatever
increases the temperature of the wood and stagnant air
(within limits) also assists.
PAINTING FLOORS.
Colors containing white lead are injurious to wood floors,
rendering them softer, and more liable to be worn away
Paints containing mineral colors only, without white lead,
such as yellow ochre, sienna or Venetian or Indian red, have
no such tendency to act upon the floor, and may be used with
safety. This quite agrees with the practice common in this
country, of painting floors with yellow ochre or raw
umber or sienna. Although these colors have little body,
compared with the white-lead paint, and need several coals,
they form an excellent and very durable covering for the
floor. Where a floor is to be varnished, it is found that var-
nish made by drying lead salts is nearly as injurious as lead
paint. Instead of this, the borate of manganese should be
used to dispose the varnish to dry, and a recipe for a good
floor varnish is given. According to this, two pounds of pure
white borate of manganese, pounded very fine, are to be
added, little by little, to a saucepan containing ten pounds of
linseed oil, which is to be well stirred, and gradually raised to
a temperature of three hundred and sixty degrees Fahren-
heit. Meanwhile, heat one hundred pounds linseed oil in a
boiler until bubbles form ; then add to it slowly the first
liquid, increase the fire, and allow the whole to cook for
twenty minutes, and finally remove from the fire, and filter
while warm through cotton cloth The varnish is then
ready, and can be used immediately. Two coats should be
used, and a more brilliant surface may be obtained by a final
coat of shellac.
The railroads consume half of the coal used in this country.
431
COLD WATER SUPPLY PIPES.
The following matter, in catechetical form, illustrates
the teachings of the New York Trades Schools in this con-
nection :
I. — What size should the pipe from the street main to
the house be ?
A. — The supply pipes of New York average about i % to
i\4 inches in diameter.
2. — What material is used for this pipe in New York ?
K — Mostly lead pipes.
3. — r^hat other materials, besides lead, are used for sup-
ply pipes ?
A. — Galvanized iron, ^rass, and tin-lined lead pipes.
4. — How is iron used?
A. — Plain, galvanized, and linecc ;nth tin or glass.
5. — What are the advantages and disadvantages of lead
pipes ?
A. — Advantages are its ductility, strength, am* easiness
of working, also its durability. Disadvantages are a^/.^er
of poisoning the water, and of being eaten by rats.
6. — What are the advantages and disadvantages of plain
iron pipe ?
A. —Advantages are cheapness, easiness of putting to-
gether, and freedom from poisoning. Disadvantages are
rusting, and filling up of pipes.
7.- What are the advantages and disadvantages of tin-
lined pipes ?
A. — Advantage is in its freedom from poisoning water.
Disadvantage in not being durable for hot -water pipes.
8. — What are the advantages and disadvantages of glass-
lined pipe ?
A. — Glass-lined pipe makes an excellent water pipe, but
is liable to break in working and putting up.
9. — What are the advantages and disadvantages of gal-
vanized iron pipe ?
A. — Galvanized iron pipe is cheap and free from rust,
but some water decomposes zinc, and its salts are poison-
ous.
10. — What are the advantages and disadvantages of
brass pipe?
A. — When brass pipe is lined with tin it is very light
and strong; but, when the tin wears off, there is danger of
poisoning the water.
ii. — What are the advantages and disadvantages of
block-tin pipe?
432
A. — They are not durable for hot water, and are very
expensive.
12. — What are the advantages and disadvantages of tin-
lined lead pipe ?
A. — They are not durable.
13. — In using tin-lined lead pipe, what must be guarded
against?
A. — The lining must not be disturbed or the tin melted
out. "
14. — How should the supply pipe be connected with
street mains?
A. — By a brass tap and coupling.
15. — How should a lead pipe be joined to an iron pipe?
A. — By a brass spud or soldering nipple.
16.— Should the supply pipe be* so arranged that it can
be emptied? and why?
A. — Yes. To prevent freezing, and the waterjfrom stag-
nating in the pipe.
17. — What precaution can be taken against freezing if
the main is within three feet of surface?
A. — By bending the pipe a few feet lower at the main,
and continuing the pipe at the lower level.
18. — In crossing an area with a supply pipe, what precau-
tion should be taken?
A. — Cover the pipe with felt, or put it in a box filled with
saw-dust, to prevent freezing?
19. — What is gained by putting a supply pipe from street
main to house in a larger iron pipe?
A. — The air in a larger iron pipe protects the supply,
and steam can be injected to thaw pipe if it freezes.
20. — How can water supply be increased after service
pipe enters house?
A. — The flow of water can be greatly assisted by using a
larger pipe after entering the house.
21. — Is there any way to arrange a pipe so that drawing
water from a lower floor will not stop or retard the flow
from upper floors ?
A. — The best way would be to proportion branches on
different floors according to pressure ; the smaller the press-
ure the larger the outlet.
22. — Suppose a three-story house had a % tap from main
to house, and connected from this tap to top of boiler with
a. 1/4 inch pipe ; what size should the branch pipes to base-
ment fixtures be ?
A. — One-half to five-eighths should be large enough.
23. — The parlor floor contains a pantry sink, a wash-
433
basin and a water-closet ; how large should the supply pipe
from basement to parlor floor be ?
A. — About I inch in diameter.
24. — How large the branch pipes to fixtures ?
A. l/z to y% in diameter,
25. — The second floor contains a bath, two Avater-closcts
and five wash-basins ; how large should the pipe from par-
lor to second floor be ?
A. — About I inch in diameter.
26. — How large should the pipe from basement t<. tank
be?
A. — About i% hich in diameter.
27. — In a building of six or more stories in height \vifcN
cold water supply drawn from tank on upper r,oors, dj.as
any difficulty occur ?
A. — Yes. On the lower floors the pressure i : too gresj.
28. — How can it be remedied ?
A. — By diminishing branch pipes to give a y-roportional
supply.
29. — Can supply pipe be so arranged tha> water can be
drawn from the main or from tank?
A. — Yes. By using a special stop-co'\ for the pur-
pose.
30. — What precautions should be tak</ . to prevent pipes
freezing ?
A. — By placing as far from frost as possible, and by
proper boxing and felting.
31. — Why are pipes liable to burst when they freeze ?
A. — The expansion expands the pipes, and, consequently,
they burst.
32. — What is the expanding pressure of freezing water ?
A. — Thirty thousand pounds to the square inch.
33. — What means are taken to thaw out a service-pipe ?
A. — The application of heat externally or steam and hot
water internally is about the best means.
34.— Is the external application of heat objectionable
with iron pipes ?
A. — 'Yes ; as the sudden contraction is as dangerous as
the expansion.
35. — In carrying supply pipes across a floor, what pre-
caution can be taken to protect ceiling below from a leak ?
A. — By putting pipes in a box lined with lead, and hav-
ing a waste, or tell-tale, pipe at lowest point.
36. — Does fresh mortar injure lead pipes ?
A. — As the lime in fresh mortar is corrosive and forms a
soluble compound, it is an injury to lead pipes.
434
PRESSURES ON TANKS.
Q. — In a full cubical tank, what is the pressure on any
Vertical side ?
A. — One-half the weight of the contents.
Q.' — In a full conical vessel standing on its base, what is
the pressure on the tmse ?
A. — Three times the we?gLt rf the contents.
Q. — In a hollow sphere, full of liquitr, \Vrt^: * ixe press-
ure on the surface of the lower half ?
A. — Three times the weight of contents.
TINNING BY SIMPLE IMMERSION.
Argentine is a name given to tin precipitated by gal-
vanic action from its solution. This material is usually ob-
tained by immersing plates of zinc in a solution of tin, con-
taining 6 grammes (about 90 grains) of the metal to the litre
(0.88). In this way tin scrap can be utilized. To apply the
argentine according to M. P. Marino's process, a bath is
prepared from argentine and acid tart rate of potash, ren-
dered soluble by boric acid. Pyrophosphate of soda, chlo-
ride of ammonium, or caustic soda may be substituted for the
acid tartrate. The bath being prepared, the objects to be
coated are plunged therein, first having been suitably pickled
and scoured, and they may be subjected to the action of an
electric current. But a simple immersion is enough. The
bath for this must be brought to ebullition, and the objects
of copper or brass, or coated therewith, may be immersed
in it.
HOW TO FIND THE AMOUNT OF STEAM-PIPE
REQUIRED TO HEAT A BUILDING WITH
STEAM.
Rule for rinding the superficial feet of steam-pipe required
to heat any building with steam : One superficial foot of
steam-pipe to six superficial feet of glass in the windows, or
one superficial foot of steam-pipe for every hundred square
feet of wall, roof or ceiling, or one square foot of steam-pipe
to eighty cubic feet of space. One cubic foot of boiler is
required for every fifteen hundrtd cubic feet of space to be
warmed. One horse-power boiler is sufficient for forty
thousand cubic feet of space Five cubic feet of steam, at
seventy-five pounds pressure to the sanare inch, w«»iohs one
pound avoinl'"^"
435
SEASONING TIMBER.
Timber, when freshly cut, contains -from thirty-seven to
forty-eight per cent, of water, the kind, the age, and the
season of vegetation go /e"iing the percentage. Older i/ood
is generally heavier thai young wood, and the weight of
wood cut in the active season is greater than that of wood
cut in the dormant season. Water in wood is not chemically
combined with the fib* -, and, when exposed to the atmos-
phere, the moisture evaj orates. The wood becomes lighter
until a certain point is reached in the drying-out process,
after which it gains or loses in the weight according to the
variations in the moisture and temperature of the atmos-
phere. Following is a table showing the percentage in
weight of water in round woods from young trees at different
lengths of time after cutting :
Kind of Wood. 6 mos. ^ 12 mos. 18 nios. 2411105.
Beech 30.44 23.46 18.60 19-9S
Oak 32.71 26.74 2o-25 20.28
Hornbeam 27.19 23.08 20.00 J8-59
Birch 39.72 29.01 22.73 19.52
Poplar 40.45 26.22 17.77 I7«92
Fir 33.78 16.87 15.21 18.00
Pine 41.70 18.67 15.^3 17.42
According to these figures, taken from actual trials, there
is nothing gained by keeping wood longer than eighteen
months, so far as drying or seasoning is concerned. In the
woods mentioned, there appears to be an actual loss in
some, and only a slow gain in others after that length of
time. The pine, fir, and beech gained moisture, and the
others in the list lost only very slightly after the eighteen
months had passed.
PROPOSED GREAT ENGINEERING FEAT.
A gigantic scheme has been proposed, by which the can-
ons of the Rocky Mountains are to be dammed up from the
Canadian boundary to Mexico, in order to form vast reser-
voirs of water to be used in the irrigation of arid lands, and so
prevent floods in the lower Mississippi. Major Powell, direc-
tor of the national survey, estimates that at least 150,000
square miles of land might thus be reclaimed — a territory
exceeding in extent one-half of the land now cultivated in the
United States. The plan is to build dams across all the can-
ons in the mountains large enough and strong enough to hold
back the floods from heavy rains and melting snows, and then
let the water down as it may be needed upon the land to be
reclaimed.
436
oN THE USE OF GLUE.
In order to use gl.w* successfully, says a writer of experi-
ence, a great deal of ^vnerience is required, and it is useless
for the amateur to try K ' j he will only spoil the work. So,
unless the workman is\\^H experienced in the treatment
and the application of the ftlue, he had better leave it alone
entirely. To render' the op Cation successful, two consider-
ations must be taken into account: First, to do good glu-
ing requires that the timber be well seasoned and thoroughly
ar /, taking care that the joints to be glued are well fitted.
'jo^t^-.!1. hi preparing the parts to be glued, each piece should
be scratched with a sharp file or piece of a fine saw, to
make the glue hold better. The shop should be kept at a
proper temperature, and the material heated so that the
glue may flow quite freely. Having the glue properly pre-
pared, spread it evenly upon the parts so as to fill up the
pores and grain of the wood, then put the pieces together
as rapidly as possible, using clamps and thumb-screws to
draw the joints tightly together ; all superfluous glue should
be washed off, taking great care not to use too much water,
or allowing any to remain on the pieces put together. The
greatest cause of bad gluing is in using inferior glue and
in laying it on unevenly. Before using a new brand of glue
it is safer to test it by gluing a piece of whitewood and
ash together, clamping it with a thumb-screw, and, when
dry, insert a chisel where it is put together, and, if the joint
separates where it is glued, it is not fit to use, and should be
rejected at once. The wood should split or give way rather
than the substance promoting adhesion. This is a practi-
cal and severe test, but it will pay to apply it, in the sta-
bility of the work.
GLUE PAINT FOR KITCHEN FLOOR.
For a kitchen floor, especially one that is rough and
uneven, the following glue paint is recommended : To three
pounds of spruce yellow add one pound, or two pounds if
desired, of dry white lead, and mix well together. Dissolve
two ounces of glue in one quart of water, stirring often until
smooth and nearly boiling. Thicken the glue water after the
manner of mush, nntil it will spread smoothly upon the floor.
Use a common paint brush and apply hot. This will fill all
crevices of a rough floor. It will dry soon, and when dry
apply boiled linseed oil with a clean brush. In a few hours
it will be found dry enough to use by laying papers or mats to
step on for a few days. WJ' *n it needs cleaning, use hot suds.
EFFECT OF THE ATMOSPHERE ON BRICKS.
Atmospheric i lilaence upon bricks, tiles and other build-
ing materials obtained by the burning of plastic clays,
depends very much on the chemical composition of the
clays and on the degree of burning. Thus, any distinct por-
tions of limestone present in them would be converted
into quicklime in the kiln, and, when the bricks were thor-
oughly wetted, would expand in such a manner as to disin-
tegrate the mass. If the clay used is too poor — that is to
say, if it contains an excess of sand — the bricks will not
become sufficiently fused, ar.d. upon exposure to the weather,
their constituent parts will separate. It is t.> be ob-erved
that in bricks, as in stones, decomposition does not take
•place \vith the greatest rapidity where constant moisture
exists, but rather where, from the absence of capillarity,
variable according to the moisture furnished by the atmos-
phere, either directly or indirectly, a series of alternatic^a
of dryness and humidity prevail.
Th» foundation walls of buildings do noi in fact suffer so
much in the parts immediately upon the ground as they do
in those at a height of from one to three feet, according to the
permeability of the materials employed. When bricks
made of clay containing free silica are laid in mortar, and
moisture can pass freely from either one or the other, it
may be observed that the edges in contact become harder
than the body of the bricks. No doubt this arises from
the formation of a silicate of lime and alumina, the lime
being furnished by the passage of the water through the bed
of the mortar.
THE GREAT EIFFEL TOWER.
Oneof the principal features of interest at the Paris Ex-
position is the Eiffel tower. It is constructed of iron, and rises
^~ ft height of 984 feet. As the greatest height yet reached
in any structure is that of the Washington monument, 550
feet, some idea can be formed of the great distance upward
that this tower will go. This tower weighs 7,000 tons, and
cost 4,500,000 francs. One object of its construction is to
light the Exposition grounds. The tower will be supplied
with elevators, which will land passengers 971 feet from the
earth. There is talk of supplying it with electric lights of
19,000,000 candle power. Four such towers, with a capacity
of 50,000,000 each, it is thought, would light the whole city
of Paris. Perhaps this tower will decide the question
whether or not it is possible to light an entire city from a
few points, if not from one.
43*
ROT IN TIMBER.
The principal cause of the lack of proper durability of
timber in buildings is the porosity of the lumber used and
the consequent liability to absorb moisture. Coarse-grained
woods of quick growth are more liable to this defect than
those of tough fiber and slow growth. When timber be-
comes repeatedly wet and dry, it becomes brittle and weak-
ened, or " its nature is gone," as the workmen say. Rot is
of two kinds, wet and dry, and moisture . is the essential
element in both cases, the only difference being that in the
first the moisture is Quickly evaporated by exposure to the
air, and in the latter, when there is no exposure, it produces
a species of fungus and minute worms which eat in between
the fibers, and gradually produce disintegration. Sap wood
is more perishable than heart wood, for the former contains
more of the saccharine, principle, and renders the wood liable
to a fermentive action.
The prevalent practice of confining unseasoned timber by
building it close into walls, thus preventing the ready evap-
oration of whatever moisture happens to get to it, is a bad
one. The ends of the wood, especially, should be sur-
rounded by an open-air space, however.small, as it is the ends
where the dampness is most liable to penetrate into the
structure of the wood. It is a well-known fact that a log of
green timber, when kept immersed, will become water-logged
and sink, and, of course, become unfit for use afterward.
The same process, only slower, applies when it is exposed
to damp with no facilities for rapid evaporation. Quick-
lime, when assisted by moisture, is a powerful aid in hasten-
ing decomposition, in consequence of its affinity for carbon.
Miid lime has not this effect, but mortar, as used in build-
ings, requires a considerable length of time to become inert
in its action as a corroding agent ; therefore bedding timber
in damp mortar is very injurious, and often the cause of un-
accountable decay. Wood, in a dry state, does not seem to
be injured by contact with dry lime, it being rather a preser-
vative. An example of this is shown in lathing covered with
plaster, which often retains its original strength when sur-
rounding timbers are completely rotted away.
Anything that will hinder the absorbing process will ex-
tend the life of a wood, such as a coating of tar, paint, or a
charring of the surface. The latter method will prove the
most effective, if sufficiently deep, as the charred coating is
practically indestructible, closes the pores of the wood, and
will prevent the bursting into flame in case of a fire. If all
439
joists, girders and inside beams of every kind were treated
to a superficial charring process, it would tend, in conjuno
tion with fire-proof paint applied to outside finishing work,
to make a building as nearly fire-proof as wood in any con-
dition will allow.
NUMBER OF BRICKS REQUIRED TO
CONSTRUCT A BUILDING.
Superficial
feet of
Wall.
Number of Bricks to Thickness of
4 Inch
8 Inch
12 Inch
i 6 Inch
2O Inch
24 Inch
i
2
3
7
15
23
30
38
45
§
68
75
IS°
225
300
375
45°
525
600
675
750
1,500
2,250
3,000
15
30
45
5?
75
90
I05
120
135
15°
300
45°
600
75°
QOO
I,O5O
1,200
1,350
1,500
3,OOO
4,500
6,OOO
22
45
68
90
"3
i35
158
i So
203
225
45o
<-75
900
1,125
i?35o
1.575
i, 800
2,025
2,250
4,500
6,75o
9,000
29 37
60 75
90 113
120 150
150 1 88
1 80! 225
2IO 263
240 300
270 338
300 375
600 750
900 1,125
1,2OO; I,5OO
1,5OO 1,875
I, §00 2,250
2, IOO 2,625
2,4OO 3,OOO
2,/Oo! 3.375
3,000 3,750
6,000 7,500
9,000 11,250
12,000! 15,000
45
90
&
22$
270
315
360
405
450
900
1.350
1, 800
2,250
2,700
3>I50
3,600
4,050
4,500
9,OOO
13>500
l8,OOO
A
t
I::;::::
7
8
9
10 . .
20
30
40
50
60. ..
70 .. . .
80 ...
QO .
IOO
2OO
3OO
4OO
Sycamore is being introduced quite extensively for interior
finish. When properly selected it makes a very handsome
finish. Care should be taken in securing it, rs it is nearly as
bad to warp as elm. It should be well backed with P'r
spruce or hemlock.
440
FIRE-PROOFING WOODWORK.
A door of the right construction to resist fire should be
made of good pine, and should be of two or more thicknesses
of matched boards nailed across each other, either at right
angles or at forty-five degrees. If the doorway be more
than seven feet by four feet, it would be better to use three
thicknesses of same stuff; in other words, the door should
be of a thickness proportioned to its area. Such a door
should always be made to shut into a rabbet, or flush with
the wall when practicable ; or, if it is a slide door, then it
should be made to shut into or behind a jamb, which would
press it up against the wall. Both sides of the door and its
jambs, if of wood, should then be sheathed with tin, the
plates being locked at joints, and securely nailed under the
locking with nails at least one inch long. No air spaces
should be left in a door by paneling or otherwise, as the door
will resist best that has the most solid material i:i it. In
most places it is much better to fit the door upon inclined
metal sliders than upon hinges.
*5 This kind of door miy b 2 fitted with automatic appliances,
so that it will close of itself when subjected to the heat of a
fire ; but these appliances do not interfere with the ordinary
methods of opening and shutting the door. They only
constitute a safegard against negligence. The construction
of shutters varies from that of doors only in the use of
thinner wood.
Under this heading may be classed all the doors of iron,
whether sheet, plate, cast or rolled, single, double or hollow,
plain or corrugated, none of which are capable of resisting
fire for any length of time ; also wooden doors covered with
tin on one side only, or covered with zinc, which melts at
700 degrees Fahrenheit,
The wooden door covered with tin only serves its pur-
pose when the wood is wholly encased in tin, put on in such
a way that no air, or the minimum of air, can reach the
wood when it is exposed to the heat of a fire. Under these
conditions, the surface of the wood is converted into char-
coal ; charcoal being a non-conductor of heat, itself tends to
retard the further combustion of the wood. But, if air
penetrates the tin casing in any measure, the charcoal first
made, and then the wood itself, are both consumed, and the
door is destroyed. In like manner, if a door is tinned only
only on one side, as soon as the heat suffices to convert the
surface of the wood under the tin and next to the fire into
charcoal, the oxygen reaches it from the outside, and the
door is ef little more value than a thin door of iron, or plain
• "
441
DIMENSIONS OF THE MOST IMPORTANT OF
THE GRE-AT CATHEDRALS.
Length, Breadth, Height,
feet. feet. feet.
St. Peter's 613 450 438
St. Paul's 500 248 404
Duomo 555 240 375
Notre Dame 416 153 298
Cologne 444 283
Toledo 395 178 ...
Rheinu.; 480 163 117
Rouen 469 146 465
Chartres 430 150 373
Antwerp 384 171 402
Strasbourg 525 195 465
Milan 477 186 360
Canterbury 530 154 235
York 524 261
Winchester 554 208
Durham 411 170 214
Ely-. 617 .78
Salisbury 473 229 279
SUGGESTIONS FOR COLORS.
In forms, tints, and colors the ocean depths supply valu-
able decorative suggestions. On silverware the iridescent
hues of tropical shells are skillfully reproduced, and on
ceramic ware their fascinating combinations of tints and the
gradations of these shells have been too much hidden away in
cabinets, instead of being studied by designers for their ele-
gant curvatures and attractive colors. The delicate -and
varied hues of the sea anemone, and the curves, volutes and
flowing lines of the univalves and bivalves are worthy of
patient stud/ with reference to graceful and fanciful orna-
mentation.
REMOVAL OF OLD VARNISH.
A Mr. Myer has just patented, in Germany, a composi-
tion for removing old varnish from objects. It is obtained
by mixing five parts of 36 per cent, silicate of potash, one of
40 per cent, soda lye, and one of sal ammoniac (hydrochlor-
ate of ammonia).
442
DECIMAL EQUIVALENTS OF INCHES, FEET AND YARDS.
Frac
Dec.
Dec.
In
Feet.
Yds.
of an
of an
of a
=
•0833 =
.0277
Inch.
Inch.
Foot.
2
=
.1666 =
•°555
1-16
=
.0625 =
.00521
3
=
•25 =
.0833
1A
=
.125 =
.01041
4
=
•33^3 ==
.mi
3-i6
=
•1875 =
.01562
5
=
.4166 =
.1389
X
=
.25 =
.02083
6
=
•5 =
.1666
5-i6
=
•3125 =
.02604
7
S3*
•5833 —
.1944
y*
=
•375 =
•03125
8
=
.666 =
.2222
7-16
=
•4375 =
•03645
9
=
•75 ==
•25
»
=
•5
.04166
10
=
•8333 =
.2778
9-16
=
•5625 =
04688
ii
=
.9166 ==
•3055
#
=
.625 =
.05208
12
=
i. =
•3333
11-16
=
.6875 =
.05729
*
=
•75 =
.06250
13-16
=
.8125 =
.06771
g
=
•8/5 =
.07291
DECIMAL EQUIVALENTS OF OUNCES AND POUNDS.
Oz.
Lb>.
Oz.
Lbs. [
Oz.
Lbs.
l/4 =
.015625
4 =
•25
8l/2
= -5313
y* =
•03125
4K =
.2813
9
= -S625
H =
.046875
5 -
•3!25
IO
==•625
.0625
5K =
•3438
II
= .6875
i^ =
•09375
6 =
•375
12
= -75
2 =
.125
6% ==
.4063
13
= -8125
2*/2 =
.15625
7 =
•4375
H
= .875
3 =
.1875
7K =
.4688
15
= -9375
3^ =
.21875
8 =
•5 !
16
1ECTS.
A person following the occupation of forming plans, draw-
ings and specifications for building purposes, representing
himself as an architect, is presumed in law not only as being
such, but to be learned in the profession.
If there is any obscurity in the drawings and specifications,
the contractor should apply to the architect for directions, or
be liable for the consequences.
There is no fixed rule as to compensation of architects in
the United States law.
The architect's contract does not survive to his represent-
ative. So, if there is a contract to complete certain work
443
for a certain sum, the representative of a deceus ..';
cannot recover for the part performance.
In Competitions it should always be made clearly under-
stood that the drawings, etc., are subject to approval, for
otherwise the party receiving them will be liable fir their
value, whether used or not.
An architect has not the right to substitute another per-
son in h's stead.
If the architect frau lulently or capriciously ie"uses t-> give
proper certificates when required, the buiVIer may maintain
an action for specific performance or against the architect for
damages.
PRESERVATION OK WOOD l;V L1MK.
I have for many years bee i in the habit of preparing
home-grown timber of the inferior sort of fir — Scotch spruce
and silver — by sfeeping it in a tank (that is, a ho'ed'igin
clay or peat, which was fairly water tight) MI a satura'ed s >Iu-
tion of lime. Its effect on the sap- WOOL: is to s-> ) a.'-den it
and fill it with pores that it perfectly resists the attacl.s of the
little wood-boring beetle, and makes it, in fact, e-]ua'!y as dura-
ble as the made wood. I had a mill which was lofted with
Scotch fir prepared in this way in 1850, and it is in perrect
preservation. The timber is packed as closely as it will lie in the
tank, water is let in, and unslacked lime is thrown on the top
and well stirred about. There is no danger that the solution
Will not find its way to everything in the tank. I leave the
wood in the solution for two or three months, by the < n I of
which time an inch board will be fully permeated by it. Joists
and beams would, of course, take a longer time for saturation ;
but, in practice, we find that the protection afforded by two
or three months' steeping is sufficient, if the scantlings are cut
to the sizes at which they are to be used.
A VERY DURABLE WOOD.
The interesting fact is stated that so indestructible by
wear or decay is the African teak wood that vessels built of it
have lasted one hundred years, to be then only broken up
because of their poor sailing qualities from faulty models.
The wood, in fact, is one of the most remarkable known, or
account of its very great weight, hardness and durability, its
weight varying from forty-two to fifty-two pounds per cubic
foot. It works easily, but, on account of the larue quantity
of silex contained in it, the tools employed are quickly worn
away. It also contains oil, which prevents spikes and other
iron work, with which it comes in contact, from rusting.
444
HOW TO BUILD AN ICE HOUSE.
I. The ice house floor should be above the level of the
ground, or, at least, should be above some neighboring area
to give an outfall for a drain, put in such a way as to keep
the floor clear of standing water.
2. The walls should b,? hollow. A four inch lining-wall,
tied to the outer wall with hoop iron, and with a three-inch
air space, would answer ; but it would be better, if the air
space is thoroughly drained, to fill it with mineral wool, or
some similar substance, to prevent the movement of the air
entangled in the fibers, and thus check the transference by
convection of heat from the outside of the lining wall.
3. A roof of thick p'ank will keep out heat far better
than one of thin boards with an air space under it.
4. Shingles will be much better for roofing than slate.
5- It is best to ventilate the upper portion of the build-
ing. If no ventilation is provided, the confined air under
the roof becomes intensely heated in summer ; and outlets
should be provided, at the highest part, with inlets at con-
venient points, to keep the temperature of the air ove*' the
ice at least down to that of the exterior atmosphere.
TESTING EXTERIOR STAINS.
Since the use of stains for exterior work became so gen-
eral, several stains, some good and some bad, have appeared
on the market, so that a few points on estimating their com-
parative values may not be amiss.
The nose, and, to a less degree, the eye, are admirable
allies for this work, but, unassisted, are not infallible. The
following is about the simplest method of testing :
1. Search for kerosene by warming, and then noting the
smell. Als >, note the thinness1 and lack of covering power
which kerosene causes. Kerosene is simply a cheapener.
2. See how fine it brushes out on a smooth shingle.
There should not be the slightest grit or any perceptible
grains of pigment, the presence of which will prove that the
coloring was mixed dry with the vehicle, and w^as never
ground fine.
3- Pour out some of the stain in a tumbler. If it begins
to settle at once, except in the case of a chrome yellow or
/green, it is made r.s above stated, by mixing a dry paint with
the vehicle, and therefore should be avoided.
A well-ground oil stain tested in this way held up a whole
day, and a creosote stain a day and a half.
Of course, when debating between two stains, it is best
445
to try them side by side. In such case the comparative color-
strength may be determined by diluting equal quantities of
both stains at about the same shade, with equal quantities of
turpentine, and then applying the diluted colors to wood, and
noting the depth of the color. One part of stain to ten parts
of turpentine is a good strength.
HOW TO PREPARE CALCIMINE
Soak one pound of white glue over night; then dissolve
it in boiling water, and add twenty pounds of Paris white,
diluting with water until the mixture is of the consistency
of rich milk. To this anv tint can be given that is de-
sired.
Lilac — Add to the calcimine two parts of Prussian blue
and one of vermilion, stirring thoroughly, and taking care to
avoid too high a color.
Gray — Raw umber, with a trilling amount of lamp-
black.
Rose — Three parts of vermilion and one of red lead,
added in very small quantities until a delicate shade is pro-
duced.
Lavender — Mix a light blue, and tint it slightly with
vermilion.
Sfrarv — Chrome yellow, with a touch of Spanish brown.
Buff — Two parts spruce, or Indian yellow, raid one part
burnt sienna.
HOW BASSWOOD MOLDINGS ARE MADE.
Bass wood may be enormously compressed, after which it
may be steamed and expanded to its original volume. Advan-
tage has been taken of this piinciple in the manufacture of
certain kinds of moldings. The portions of the wood to be
left in relief are first compressed or pushed down by suitable
dies below the general level of the board, then the board is
planed down to a level surface, and afterward steamed. The
compressed portions of the board are expanded by the steam,
•""o that they stand out in relief.
BUILDING BLOCKS MADE OF CORNCOIJS.
Building blocks made of corncobs form the object of a
new Italian patent. The cobs are pressed by machinery into
forms similar to bricks, and held together by wire. They are
made water-tight by soaking with tar. These molds are very
hard and strong. Their weight is less than one-third of that
of hollow brick, and they can never get damp.
446
RED V. 001) FINISH.
The following formula a«*d directions Lave been highly
recommended.
Take one quart spirits turpv. \tine.
Add one pound corn starch.
Add % " burnt sienna.
Add one tablespoonful raw linseAl oil.
Add " *' brown Jaj.\ n.
Mix thoroughly, apply with a bnu\\ let it stand say fif-
teen minutes; rub off all you can with -fine shavings or a soft
rag, then let it stand at least twenty-fonr hours, that it may
sink into and harden the fibers of the wood; afterward apply
two coats of white shellac, rub down w^l with fine flint
paper, then put on from two to five coats bt*t polishing var-
nish; afier it is well dried, rub with water ami pumice-stone
ground very fine, stand a day to dry; after being washed
clean with chamois, rub with water and rotten-stone; dry,
wash as before clean, and rub with olive oil unti! dry.
Some use cork for sand-papering and polishing, but a
smooth block of hard wood, like maple, is better. When
treated in this way, redwood will be found the peer of any
wood for real beauty and life as a house trim or finish.
A NEW WALL PLASTER.
A new material for use instead of common plaster is- ow
prepared, which offers many advantages, as it can be apj vd
more quickly, and dries in less than twenty-four hours. It
is impervious to dampness, and there is no possibility of the
window and door casings contracting or swelling and causing
cracks, as very little water is required in the mixing. It is
known as" Adamant " wall-plaster, and deserves its name, as,
when once dry, it is very hard to- break. From a sanitary
point of view, it is also valuable, as it is non-absorbent.
A RELIABLE CEMENT.
A reliable cement, one that will resist the action of
water and acids, especially acetic acid, is : Finely powdered
litharge, fine, dry white sand and plaster of Paris — each
three quarts by measure — finely pulverized resin one part.
Mix ar,d make into a paste with boiled linseed oil, to which
a little dryer has been added, and let it stand for four or five
hours before using. After fifteen hows' standing, it loses
Strength. The cement is said to ha\v bcvn successfully used
in Zoological Gardens, London.
447
PAVEMENTS.
Bricks, impregnated at a warm temperature with as-
phaltiun, have been successfully used in Berlin, for street
pavement. After driving out the water with heat, bricks
will take up from fifteen to thirty per centum of bitumen,
and the porous, brittle material becomes durable and elastic
under pressure, the bricks are then put endwise on a beton
bed, and set with hot tar. It is said that the rough usage
which the pavement made of these bricks will stand is aston-
ishing. A fe\v yenrs ago, in California, a pavement was laid
of bricks, those tint were soft-burned being selected, which
were sat Ufa ted with boiling coal tar. They were placed end-
wise on a bed of concrete, and the interstices filled with the
hot tar. sind being scattered to the depth of about one-half
(^2) inch upon the pavement, and afterward swept off. And
now we learn from an exchange that bricks impregnated
with creosote or bitumen have been adopted for paving pur-
poses in Nashville, Term., and with very satisfactory results.
The wear is very uniform, as the softer and more porous
bricks absorb more bitumen, which has the effect of harden-
ing them, at tlri same time making them absolutely imper-
vious, and thus protecting them from the disintegrating effect
of frost. It is stated that pavement of this type, exposed
for three and a half (3^) years to the wear of fairly heavy
traffic, was. at the end of that period, found to be in excel-
lent condition. The process of bitumenizing, however,
rather more than doubles the cost of the brick.
A POLISH FOR WOOD.
The wooden parts of tools, such as the stocks of planes
and handles of chisels, are often made to have a nice appear-
ance by Freivjh pol;shing ; but th's adds nothing to their
durability. A much better plan is to let them soak in lin-
seed oil for a week, and rub with a new cloth for a few min-
utes every day for a week or two. This produces a beauti-
ful surface, and has a solidifying effect on the wood.
TO CALCULATE THE NUMBER OF SHINGLES
FOR A ROOF.
To calculate number of shingles for a roof, ascertain num-
ber of square feet, and multiply by four, if two inches to
weather, 8 for 4^ inches; and 7 1-5 if 5 inches are exposed.
The length of a rafter of one third pitch is equal to three-
fifths of width of building, adding projection.
VALUABLE FIGURES.
The following figures are wortfi remembering, as they
will save a good deal of calculation and give approximately
accurate results with a minimum of labor :
A cord of stone, three bushels of lime and a cubic yard
of sand, will lay one hundred cubic feet of wall.
Five courses of brick will lay a foot in height on a
chimney.
Nine bricks in a course will make a flue eight inches wide
and twenty inches long, and eight bricks in a course will
make a flue eight inches wide and sixteen inches long.
Eight bushels of good lime, sixteen bushels of sand
and one bushel of hair, will make enough mortar to plaster
one hundred square yards.
One-fifth more siding and flooring is needed than the
number of square feet of surface to be covered, because of the
lap in the siding and matching of the floor.
One thousand laths will cover seventy yards of surface,
and- eleven pounds of lath nails will nail them on.
One thousand shingles laid four inches to the weather,
will cover one hundred square feet of surface, and five pounds
of shingle nails will fasten them on.
FROSTED GLASS.
Verre Givre, or hoar frost glass, is an article now made
in Paris, so called from the pattern upon it, which resembles
the feathery forms traced by frost on the inside of the win-
dows in cold weather. The process of making the glass is
simple.
The surface is first ground, either by the sand blast or
the ordinary method, and is then covered with a sort of
varnish. On being dried, either in the sun or by artificial
heat, the vainish contracts strongly, taking with it the parti-
cles of glass to which it adheres ; and, as the contraction
takes place along definite lines, the pattern produced by the
removal of the particles of glass resembles very closely the
branching crystals of frostwork.
A single coat gives a small, delicate effect, while a thick
film, formed by putting on two, three or more coats, con-
tracts so strongly as to produce a large and bold design. By
using colored glass, a pattern in half-tint may be made on the
color eel ground, and, after decorating white glass, the back
may be silvered or gilded.
449
PERFECT MITERING.
BY OWEN B. MAGINNIS.
The many awkward ways in which so many woodworking
mechanics endeavor to mark and cut in soft and hard wood
moldings, and the botching results of their efforts, has in-
duced the writer to give the following simple and successful
methods which are perfect in their accuracy.
The different conditions which exist through the careless-
ness of those who precede him, when an operator commences
to set in his molding, often cause him much trouble and loss
of patience, as for instance, a molding being run standing on
the little rebated lip or a raised molding being out of square,
or an obtuse angle, instead of a little tinder^ or an acute
angle. This will of course necessitate, either the re-rebating
of the molding by hand, or taking the arris of the corner of
the panel sinkage as shown at A. Fig. i. Then the molding
FIG. i.
is often stuck too thin for sinkage, as will be clearly seen on
the left hand side of the panel at B, and again the surface of
the door, on account of the inequalities of the thickness of
the pieces, especially on the back side, often varies as much
as iJg of an inch. This difficulty is easily overcome by the
following sure process.
Take a small strip, and, placing the end of it down in the
corner, mark the arrises with a sharp pocket knife. Measure
these depths; in the case shown here they will be, for exam-
ple, respectively, ^-inch, ^-inch, -jJg-inch, full, ^-inch full,
and ^-inch, scant. Having done this, make 4 strips, or saddles,
450
equal in width to the different depths of thesinkage, as j^-inch
wide, ^—fg wide, and so on, each being about %-inch thick and
long enough to go into the miter box between the saw cuts.
FIG. 2.
Plac? it in the box as represented at Fig. 2, with the lip of
the molding resting on the saddle as it will rest on the door-
frame, at the miter and saw the left-hand end (say on the ^
scant saddle): To get the neat and exact length without
gauging on the door. From the point where the saw crosses
the saddle at Fig. 3, square across the bottom of the box
with the Den-knife. These lines are the neat and exact
lengths for either end, so if the thin edge — B, Figs, i and 3,
of the molding, be marked at the opposite arris, holding the
already mitered end close into its corners — and then this
mark be placed at the asterisk or intersection, and the
molding sawn on the saddle necessary for the opposite cor-
ner (say l/2 full saddle), and so on all around the panel, it
will, if cut out of one piece, perfectly utersect in its profile,
*he lip will come to a close joint on the frame, and the thin
sdge close to the panel. The dotted line in Fig. 3 shows
now the molding should be neld down in the box. The best
way is tolry a pair of pattern pieces as shown at Fig. I (on
the nedBRry saddle), trying the patterns in each corner.
r
?• miMft
' 1
2, T •-+ n
1
x y - 1
Fig. 3-
By this means it will be easy to find the exact saddle which
will bring a good miter. Be sure they will come right
tbefore commencing to cut the molding all round. If it be
too thick for the sinkage, of course it must be planed down
on the back until it is a shaving thin, so that it will not strike
the fillet, but press closely on the panel.
Great care should be exercised in cutting die miter box, as
451
perfect mitering is almost reliant on a good box, cut exactly
on the angle of forty-five degrees. To set the level, lay o«t
a square on a drawing-board about four inches wide. Join
the opposite angles like at Fig. 4 (be certain it is exact to a
hair, or the bevel will not reverse itself). Place the bevel on*>
to the lines joining the angles as it lies on the board and
mark the miter box by it. This is the only perfect way to
miter and cut in raised moldings, and will always, without
error, assure accuracy and good mitering.
Fig. 4.
Mitering flush molding or molding which does not rise
above the surface of the frame is comparatively simple, and
is usually done with a jack, except in the case of large mold-
ing. All that is necessary is to first miter the left-hand end
and mark the right hand.
The handiest way is to commence at the right-hand
corner next to you, and work to the farthest corner, and soon
all round, returning to the one started from. Should the
lengths, when placed in the panel before drawing down, be
too long, take a rebate plane, shaving off until they be a snug^
tight fit.
THE VENTILATION OF BUILDINGS.
Perhaps no single feature of modern architectural construc-
tion is likely to secure such immediate regard in the near
future, and is already so conspicuously engaging the attention
of the foremost men in the profession, as that of proper ven-
tilation. Nor can it be denied that no feature is more im-
portant for health considerations in private homes, office
452
buildings and public institutions, than the securing of a
steady supply of pure air and the coincident and correspond-
ing removal of the vitiatec1 air, so that the atmosphere in the
rooms is, at all times, fresh and pure. The two points cov-
ered in the last sentence constitute what is known as, and is
technically termed. ."ventilation."
The expedients for obtaining a supply of fresh air to the
room, so that there is a constant dilution and consequent
bettering of the atmosphere, are comparatively simple.
They merely imply that the air warmed by the hot-air fur-
nace or steam coils in the cellar be taken from a place where
It is pure (not, for instance, above a cesspool), that the ducts
in cellar, through which the air travels, be air-tight (prefer-
_ly ;i .Abstracted of No. 22 or No. 24 galvanized iron,
rather than of wood), and that some automatic means be
adopted to regulate the temperature of the air supplied to
the rooms, without shutting off such air supply. Or, when
steam radiators are in rooms, that they be placed below win-
dows, and air pass by means of proper orifices from outside
through the radiators.
Furthermore, in large structures, a fan driven by electric
or steam power is often instituted for forcing in a larger
amount of fresh air than could be secured by the natural
suction of the warmed air.
But the mere supply of warmed fresh air to the rooms is
not enough. For note, if the air in the room has no escape,
it does not take long, whatever the fresh air supply, before
tbe vitiated air contaminates and makes foul the air as it
enters the apartment. To open the windows is the remedy
which the uninitiated at once suggest, and, in fact, in most
houses this is the only palliative at hand.
It is, however, one of the first principles of ventilation,
that the windows must not enter as an expedient. In a
properly ventilated building the windows should never be
open when people are in the rooms, at least in the winter
months. For, opening the windows secures the admission of
cold air in bulk, but does not remove the foul air, and more
especially causes pneumonia-giving draughts, and chills the
room, and in this way more damage is done than by even the
presence itself of vitiated air in the rooms.
A warm or hot room does not necessarily signify an im-
pure atmosphere; while we may have a room cold and the
atmosphere still terribly ynpure. The unthinking never
take this into account, and are apt to confuse the term warm
with impure, and the term cold with pure atmosphere, as far
as the rooms they are in are concerned.
453
The proper way to remove the vitiated air is by means et
vent-ducts, or vertical flues leading from the rooms to the
roof of the building. These flwes should have an aggregate
cross-sectional area at least equal to, and preferably about
ten per cent, greater than, the cross-sectional area of the
fresh air inlets; and should be situated on the opposite
(preferably diagonally opposite) side of the room.
These vent -ducts should have openings controlled by
registers, near the floor and near the ceilings of the rooms,
but the two registers should not be opened at the same time.
The cross-sectional area of the registers should be twenty-five
per cent, more than that of the vent-ducts.
The bottom register is the one ordinarily to be used; for
the heavy, vitiated air sinks to the floor, while the fresher, un-
polluted air rises. When the people in the room are smoking
profusely, it is better to close the bottom and open the top
registers of the vent-ducts, for the smoke rises to the top,
and is then more speedily removed.
These vent-ducts cause a gentle draught in the same way
that a chimney of a steam boiler or hot-air furnace does.
The temperature in the room being higher than that of the
external air, the temperature in the vent-ducts is also higher,
and consequently a draught or removal of the vitiated air is
secured, the amount depending on the area and height of the
duct, and the difference of temperature between the ex-
ternal air and the air in the room. This system is known as
that of natural ventilation.
To make this removal of vitiated air still more rapid than
is secured by the natural draught just mentioned and ex-
plained, one of several expedients may be adopted. An
exhaust-fan, driven by steam or electric power, may be placed
near the top of vent-duct, and the air exhausted from duct by
means of this fan, thus increasing the fresh air supply through
fresh air inlet. This is frequently adopted in public build-
ings, where the rooms are, at times, full of people. Or the
temperature of the air in the vent-ducts, and consequently
the drabght and the removal of vitiated air, may be in-
creased by any of the following means:
1. Gas jets may be burned in the vent-flues near the bot-
tom.
2. Steam risers, through which steam of high or low
pressure circulates, may run through the vent -ducts.
3. Such steam risers may have a large coil near top or
right above vent-flues proper.
For private homes and dwellings; natural ventilation
suffices. For public buildings and large halls, either the fan
454
or the stt?am system should be preferably adopted. The gag
jets give out a comparatively little additional heat, but are
mexpensive in first cost, and in running expense.
In a paper " On the Relative Economy of Ventilation by
Heated Chimneys and Ventilation by Fans," read by Prof.
Wm. P. Trowbridge, of the School of Mines, Columbia Col-
lege, before the American Society of Mechanical Engineers,
Prof. Trowbridge decides that in all cases of moderate ven-
tilation of rooms or buildings, where, as a condition of health
or comfort, the air must be heated before it enters the rooms,
and spontaneous ventilation is produced by the passage of
this heated air upward through vertical flues, such ventila-
tion, if sufficient, is faultless as far as cost is concerned. He
consideres this a condition of things which may be realized
in most dwelling houses, and in many halls, school-rooms and
public buildings, inlet and outlet flues of ample cross-section
being provided, and the heated air being properly distrib-
uted.
If, however, starting from this condition of things, a more
active ventilation is demanded, the question of relative econ-
omy of fan and heated chimney is not so simple a problem.
Prof. Trowbridge points out that ventilation by chimneys is
disadvantageous under one point of view in any case, viz : the
difficulty of accelerating the ventilation at will when larger
quantities of air are needed in emergencies; while the fan
or blower possesses the advantage in this respect, that by in-
creasing the number of revolutions of the fan the head or
pressure is increased. This latter fact makes the fan prefer-
able for the ventilation of hospitals or public buildings of
considerable magnitude, whenever, as is customary, the activ-
ity of the ventilation must be varied occasionally.
Where the power required is only a small fraction of a
horse-power, as in ventilating single large rooms or small
buildings, Prof. Trowbridge concludes it to be evident that as
regards cost of fuel and the care and attention required, ven-
tilation by heated chimneys is preferable, except, of course,
for cases where a fan is driven by machinery employed for
•ther purposes than ventilation, the cost of attendance charge-
able to ventilation being then trifling and the fan evidently
being more appropriate.
The construction of the building, of course, enters as an
important factor, and often precludes the adoption of the ex-
haust-fan system. In large structures it is always important
to take into account, and decide upon, the system of ventila-
tion before the plans of the building proper are finished or
finally adopted.
45i>
BURYING A SCREW HEAD OUT OF SIGHT.
To get the heads of nails and screws out of sight, where
glue can be used without any objection, just raise up a chip
with a thin paring chisel, as shown in the drawing, and then
set the nail in solid. This." leaf" can be covered with a coat-
ing of glue and laid back again in place, where it must fit on
all sides to perfection. A dead weight will hold everything
in place till the glue dries, and a few moments with the
scraper makes the job complete. It will add to the nicety of
the work to draw lengthwise with the grain two deep cuts
with a thin case-knife just the width of the chisel, and this
keeps the sides of the chips from splitting. The chisel should
be set at a steep angle at first till the proper depth is reached,
and then made to turn out a cut of
even thickness until there is room to
drive a nail. If too sharp a curve is
given, the leaf is likely to break apart
in being straightened out again. In
blind nailing a narrow chip is taken
' with a tool made especially for this
purpose, that lifts the cut just high
enough to let in the nail on the slant,
a set slightly concaved, being used to
keep it from ever slipping off the
head, and the upraised cut driven
down again with the hammer.
HIP AND VALLEY ROOF FRAMING.
A simple way of laying out a hip or valley roof and
finding the length of jack rafters, cuts and bevels, is shown
in the accompanying sketch. The method followed is com-
paratively simple and easily understood.
Lay down the plan of the building A^ B, C, D, find the
center line of the ridge E F, and show the plan of hips A F
and B F, also the jacks G H and IK.
To find the length of the common or straight side rafters,
lay off on the ridge line E F the height of the pitch E M.
From the point A7", which is the outside edge of the wall
plate, join N M. This will give N M as the extreme
length, on the upper edge, of the common rafter which is to
stand over the seat E N.
, In order to find the length of the hip rafurs whichi will
stand over the seats C E or B F, draw the line O E
square with the line E C, and make O £=M E the height
of the pitch. Join the point C with the point Ot thus
456
obtained, which will give the length to the hip rafter on its
upper edge.
The length of the jack rafters is generally obtained by
direct measurement, but the following method will be found
correct. Produce the line N E> and make N P equal to
the length of the common rafter, so that N P=M N^ join
P C, which, will equal C O; produce the seat of the jack
JD
rafters k i and g h, until they intersect P C in / and m9
and then / / and g m will be the correct lengths for the
jack rafters.
In raising a roof of this description, it is usual to cut the
ridge E F and the common rafters which abut against it at
each end as at R F. In placing them in position they are
fastened plumb over their seats by braces, and the side
rafters are placed each against its mate, as / against /, 2
against 2, j» against j», and so on.
When all the side rafters are in position, the hips are
inserted, and their accompanying jacks.
PAINTING AND VARNISHING FLOORS.
A French writer observes that painting floors with any
color containing white lead is injurious, as it renders the
Vrood soft and less capable of wear. Other paints without
white lead, such as ochre, raw umber or sienna, are not in-
jurious and can be used with advantage. Varnish made of
drying lead salts is also said to be destructive, and it is
reccpmmended that the borate of manganese should be used
to dispose the varnish to dry. A recipe for a good floor var-
457
nish is given as follows: Take two pounds of pure whit*
borate of manganese, finely powdered, and add it little by
little to a saucepan containing ten pounds of linseed oil, which
is to be well stirred and raised to a temperature of 360° Fahr,
Heat 100 pounds of linseed oil in a boiler till ebullition tak«e
place; then add to it the first liquid, increase the heat and
allow it to boil for twenty minutes. Then remove from tbft
fire and filter the solution through cotton cloth. The var-
nish is then ready for use, two coats^ of which may be used,
with a final coat of shellac, if a brilliant polish is required.
A COLOSSAL STICK OF TIMBER.
A colosal stick of lumber from Puget Sound has been con*
tributed to the Mechanics Exhibition at San Francisco. Its
length is 151 feet, and it is twenty by twenty inches through.
It is believed to be the longest piece of timber ever turned out
of any saw mill.
A few years ago mechanics cared very little about winter
work of any kind. They rather looked forward with pleas*
ure to the prospects of a long rest. Things have been chang-
ing recently, and the tendency now is to secure all the winter
work possible: One reason is, there are more building and
Joan associations, more insurance societies, more lodges and
more organizations of one kind and another, all of which
must be kept up. Besides, there is an increasing amount of
work that has heretofore been done in summer. The cost of
labor in a good many vocations is less in winter than it is in
summer, owing to the small amount to be done and the greater
number seeking it.
PLASTER FOR MOLDINGS.
Where walls and ceilings are to be molded whilst yet in a
plastic state, some decorators are using a fibrous plaster, with
(he object of securing greater firmness and tenacity. The
idea itself is not new, animal hair having formerly been inter-
mixed with lime, but this is a new application. In England
and France a fine wire netting is at times inserted between
two courses of plaster, to afford greater firmness in holding
picture frames. The tenacity of some of the old moldings
in old New York houses, whilom aristocratic, is very
remarkable, retaining as they do their original sharpness of
outline.
458
THE SWEATING OF CHIMNEYS.
The sweating of chimneys is now believed to be due to
condensation of the moisture in the air that is confined in a
poorly ventilated chimney flue. The trouble, as our corre-
spondent indicates, is chiefly to be found occurring in small
chimneys, and in such chimneys whose flues start from the
second or third story of a building. The sweating is the
most copious when a fire is started in a place that has been
for some time in disuse, or, in other words, when the flue is
cold. The humidity of the air is a large factor in the
phenomena of sweating. If the air be charged with moisture,
the flue cold, and a fire newly kindled, the conditions are
favorable for sweating. It is only under these favorable
conditions that a well- ventilated chimney will begin to sweat,
but the sweating will not continue. If sweating should
continue in a chimney after a fire is fairly under way, it can
be safely concluded that the chimney needs an opening near
the ground to provide a better circulation of air within the
flue. It may be, as our correspondent suggests, that rain
may beat in and cause the same effect as sweating, especially
where the rain has continued for several days together, and
in that case a cowl, such as has been lately described in
"Building, in House and Stable Fittings," would cure the
disease by excluding the rain; but such occurrences are
exceedingly rare, and we have seen chimneys guilty of sweat-
ing that were provided with the most approved form of cowl,
:.^1 the remedy applied has been to insert an air-brick at the
nase of the chimney to secure better ventilation, so as to
lessen condensation, and the device has proved successful.
Cowls prove useful only so far as they promote ventilation
by increasing the circulation within the chimney flue. A
cowl may be so improperly applied to a flue as to promote,
instead of abolishing:, sweating. The main point is to pro-
vide an ingress of air sufficient to tax the extractive capacity
of the cowl that is used.
ELECTKIC LIGHTS IN GEEMANY.
According to Dr. Schilling, the number of electric light .
installations in the 13 principal towns of Germany has in-
creased during the last two years from 131 to 604; the num-
ber of arc lamps has increased from 591 to 3,280, and the
number of incandescents from 10,403 to 50,469. The num-
ber of gas lamps in these 13 towns is 1,221,882, and there-
fore, lamp for lamp, electricity furnishes about four per cent
of the total illumination •
459
SMOKY CHIMNEYS AND HOW TO CURE THEM.
A smoky chimney is a complaint we are often called upom
to deal with, and the best way of building chimneys whick
should not smoke into the rooms, and of remedying existing
chimneys which are liable to do so, is a matter of great im-
portance to estate clerks of works. There are many small
matters in building new chimneys which, together, may be a
means of preventing them from smoking at the wrong end ;
but my intention at present is to deal crJy with the shaft or
stack, or portion outside the roof, and my object is not to
give ornamental elevations of chimney heads, which are un-
necessary for the purpose of this article, but to explain a way
of forming them which I have many timesfound to give relief
to inveterate smokers. A common shaft, such a one as
would be adapted for existing old cottages, is 2^ bricks «r
I ft. 10% in. in width, and in my opinion none should be lesi
than this, with a 9-inch earthenware flue-pipe built in solid;
this I usually commence on the damp course, which should
be just above the flashings of roof. As the area of the round
pipe is smaller than the 14-inch by g-'mch brick flue
on which it is placed, a quicker current of air or draught is
thereby generated, and in windy weather a check is given to
sudden down-draughts. Another advantage in a flue-lined
stack is that there is no danger of the brickwork cracking
when the soot in the flue is on fire, and which, owing to the
scarcity of chimney-sweeps, is often the case in countryplaces.
Stoneware drain pipes, however, are quite unfit, as they are
Kable to split with the heat ; but the tubes made of fire-clay
or terra-cotta, only should be used. Another help is to keep
the stack dry ; a damp flue is generally a smoky one, and if a
fire is lighted in the fire-place, say, of a disused bed-room, it
is a common occurrence to see the smoke puff down violently
and the chimney is said to have a down-draught, and by many
people is assumed to be badly constructed, whereas, perhaps,
it may be built in the best possible manner except that it will
not keep out rain and damp. ' The rain may come through the
sides of the stack, or it may comedownward through the head %,
at any rate the chimney for some distance from the top is, in
wet weather, cold and soppy. I roof the chimney top with
plain tiles, with the object of protecting the head and
permitting the rain to drop off at the eaves instead
of running down the stack and making the flue cold,
and 'the stack outwardly black and soot stained I
bed the tiles in cement, using copper nails driven into the
latter through the pin holes — or a plain, cemented we
460
ing looks fairly well. But by forming the covering with tiles
a good drip is obtained, which is not so readily done with
cement. Another point is not to make the slope or
pitch of a suitable angle, and this, in my opinion,
should be about 45 degrees, as I find that inclination most
effectual; when the wind strikes the slope it takes an upward
direction, and, as a matter of course, carries the smoke with
it.
Some time since a gentleman living by the seaside was
much troubled with smoky chimneys, and asked me what
was the best thing to do ; I told him near about what I have
just now written, and a short time afterward I received a letter
(which I must confess somewhat scared me) saying he had
decided to pull down his chimneys and rebuild them on my
principle, and desired me to order for him two truck loads of
George Jennings' flue pipes at once. This I did, and waited
anxiously for the result; at last I was gratified by hearing
" Chimneys are a great success," but it was summer time, 'and
I was not so sure how they would act in cold, boisterous
weather by the seaside, where every patented smoke-curer
had apparently been tried by some one or other ; but eventu-
ally I was glad to learn that they continued to draw well.
*fy I have proved this system of chimney stack building to be
good in a large number of cases ; for instance, my office
chimney is directly under the branches of a large tree, and
the fire is on the hearth, yet I am never troubled with smoke.
For economizing heat in single houses or detached cot-
tages, we all know it is the best plan to get the chimney on
the inside, and not forming a portion of the outer walls, as in
the latter case they are much more likely to smoke, and we
also know that register grates, or grates with doors a few
inches above the fire, generally make the fire draw ; they not
only draw the smoke, but a greater portion of the heat as
well, and necessitate getting very close to the fire to obtain a
portion of the heat going up the chimney. To my mind,
there is nothing to equal a fire on the hearth, and wood, if
Vou can get it, in preference to coals.
There is much might be said about set-offs in flues, and I
know they are objected to as a rule, but I believe a chimney
with- one or two set-offs is all the better for it. I also
believe chimney heads built in cement mortar true economy;
the latter makes good work and looks well, long after chim-
ney heads built with lime mortar, which soon show startling
mortar joints and crumbly bricks. How often do we find
old chimney heads want repointing, for the wcather loosens
the mortar and the birds carry it away.
461
The summary of my experience is briefly this:
1. Put a damn course to new chimneys, or insert one in
old chimneys.
2. Line the chimneys with fine pipes above the damp
course.
3. Roof the chimney tops 'carefully.
4. Don't forget a good projecting eaves-drip to the chim-
ney-head.
4. Build the heads with cement mortar.
FACTS ABOUT FURNACES.
In February, 1881, the committee of hygiene of the Medi-
cal Society of Kings County rendered a report, which is
published in full in the proceedings of that society, upon
catarrh, and whether ^that disease was aggravated by resi-
dence in cities. The opinions of a large number of phy-
sicians of long experience were obtained, and their testimony
showed "that, though climatic and city influences have much
to do with the creation of catarrh, yet defective heating,
lighting, airing, sunning and drainage of houses, with im-
proper views as to air, clothing, bathing and exercise, are
the main causes," Individual physicians laid special stress
upon individual influences, as "dry and irritating air from
villainous furnaces, increased furnace heat and artificial
methods of living."
Furnace air per se is not so unwholesome, but it is the
absence of ventilation which makes it so. If a furnace is of
sufficient size to warm a building without opening every
draft and heating the fire-pot red-hot, and if the fresh air
supply is taken from a proper source and not from a damp
area or unclean cellar; and, furthermore, if there are suffi-
cient openings at the top of the house to allow the impure
air which rises to that point to escape and thus cause a con-
stant circulation of sufficiently warmed but not overheated
air through the house, under these conditions a furnace is
not objectionable.
Furnaces are often badly located. It is easier to force
warm air through a furnace flue fifty feet away from the
prevalent wind than ten feet in the opposite direction.
Mence the furnace should be placed nearest the northern
side of the building, or two should be provided. Hot-air
flues should not be carried for any distance through cold cel-
lars, halls or basements, as they will become chilled, and
will not draw without being cased With some non-conducting
material, as mineral wool.
462
Don't set a furnace in^a pit, especially in a wet soil where
water will collect after every rain storm, but stand it on
brick arches, so as to raise it above the ground ; also cement
the pit. It is unfortunately very common to find such
depressions filled with water ; this causes rusting of the fur-
nace itself and damp in the cellar. In very many houses
occupied by persons of means, the furnaces are no longer
used, but have been replaced by open fires. This is costly
comfort, but it is a commendable plan, as k furnishes ample
ventilation to the living rooms. It is desirable that one room
should at least be thus supplied with a careful and sanitary fire.
Where fresh-air inlets are carried from the house drain to
the front of a house at the yard level, they should not be
located near to the cold-air supply, as there is a chance that
during heavy states of the atmosphere a down-draft may be
created, and the foul air sucked into the air box and thence
upward into the house. Registers should never be placed at
die floor level, as they will collect dust and sweepings, which
are liable to take fire.
Furnaces with heavy eastings heat slowly and are less easily
cracked or warped, and they cool more slowly, so that the
heat evolved is more uniform. It is well to retain the air
close to the fire-pot, and thus keep it longer in contact with
the fire-heating surface.
Water pans are often badly arranged so that they admit
dust, and as they are seldom cleaned that may become offen-
sive. They should always be supplied by a ball-cock so as to
be automatic, rather than by a stop-cock which has to be
opened by a servant, who may be neglectful.
Attempts have been made to filter the air before entering
the furnace, but they usually fail. A screen of galvanized iron
wire of 1-16 mesh will exclude most floating material from
the air. The air supply is sometimes taken from the attic,
but it is apt to be dusty and impure. Others take it from
vestibules of halls or piazzas, which are not bad places.
STEAM vs. HOT-WATER HEATING.
Hot water as a heating agent is one of the oldest in use,
*nd has a number of advantages in its favor. For mild
climates it answers very well. For northern latitudes, how-
ever, and in countries such as Canada and most of our north-
ern States, having long, severe winters, hot-water heating is
not in general use on account of the following objections:
High First Cost — Hot water, as generally used, only-
gives off two-thirds the amount if IK at per square foot of
radiating surface which steam will give under similar cir-
cumstances. To get the same results as from steam it
therefore requires about fifu per cent more of radiators,
and a corresponding increase of piping
Added to the expense of this extra material is that of
labor, which increases in the same proportion, thus
making the entire first cost of hot water about one-
third higher than steam
Leakage — As all the pipes are continually full of water,
any leakage will rapidly flood the house, causing trouble
and damage. With steam , the flow-pipes contain no water
whatever, and the return drip-pipes but very little, so
that in event of a leakage the w-ate would be discovered
and stopped long before it could do any damage.
No Way to Shut Off— We have never yet seen a hot
water radiator which can be turned off and yet allow the
water within it to flow back to the boiler, the construc-
tion of the radiator being such that all the water must
circulate up and down between divisions connected
alternately at the top arid bottom. »
When the radiator is turned off, these divisions still re-
main full of water which has no chance to run off. It is
therefore necessary to keep all the radiators in the house
running all the time, or else take the chan?es of their
freezing and giving trouble if they are shut off. Now
there are certain rooms in almost every house, such as
guest-rooms, which are only occupied occasionally, and
it would be a useless expense and inconvenience to keep
them constantly warmed. The advantage of steam over
hot water in this respect is evident. With steam you can
shut off any radiator you please, and keep every room in
your house at the exact temperature disired, without in-
convenience or waste of heat.
Freezing and Bursting — It is a curious fact that hot
water will cool down and freeze much quicker than ordin-
ary water under the same circumstances. The first effect
in boiling water is to drive off all its air, hence, becoming
more solid and condensed, it is very susceptible to cold
and will freeze very easily. If the fire in the boiler from
any reason goes out, the water of course soon stops circu-
lating, and in cold weather the pipes will rapidly freeze
and burst. Many instances are on record where immense
damage has been done from this cause. The use of steam,
on the other hand, entirely precludes this cause.
464
Difficulty of Regulation,.— In zero weather it is difficult to
keep warm by hot water, unless there is a great amount of
heating surface, and then in mild weather you aiv liable at
any time to have too much heat. This is especially notice-
able in any sudden change of temperature.
Hot water, being slow in acquiring heat and slow in part-
ing with it, is consequently difficult to regulate with any
degree of satisfaction.
This feature is seen in greenhouse heating particularly.
When the sun is shining, on account of the great amount of
natural heating glass surface, the temperature soon runs up
above the normal, causing a necessity for opening the ven-
tilators and so wasting the heat. And should the tempera-
ture once get down, it takes a long time to get it up again.
The advantage of steam in this case is apparent, as it is
capable of being handled nnd regulated rapidly, and there-
fore is superior to any other method wherever an even and
uniform temperature is desired either for a greenhouse or a
dwelling.
Comparative Economy.— Careful experiments have recently
been made by parties owning many greenhouses— some of
which are warmed by steam and others by the most approved
of hot-water heaters— for the purpose of accurately deter-
mining the relative cost of fuel in each case. They had
nothing to gain by such experiments except the truth, as,
with all florists, coal is a very heavy item and one of the
principal expenses attending the running of a greenhouse.
Without entering into details, it has been demonstrated
that greenhouses may be heated by steam on two-thirds the
quantity of coal required for a hot-water apparatus. This
fact has become so well established, that to-day steam is
very rapidly taking the place of every other method for
warming greenhouses.
The objections to hot water for this class of buildings is, ,
moreover, much less than for residences, on nearly all the
preceding five points. For instance, a leakage of a pipe can
do no harm, as in a house, and there is, of course, no occa-
sion to shut off any portion of the system, as is sometimes
desired in a house. \-
^Although the expense of a change from hot water to steam
is heavy, yet the advantages secured are so great and ap-
parent th?-t it will not be long before hot water as a heating
agent will be practically abandoned in every kind of building.
INTERESTING FACTS ABOUT ISINGLASS.
Isinglass consists of the dried swimming bladder of fishes.
The bladders vary in shape, according to their origin, and
they are prepared for the market in various ways. Some
are simply dried while slightly distended, forming pipe
isinglass. When there are natural openings in these tubes
they are called pursers. When the swimming bladders are
slit open, flattened, and dried, they are known as leaf isin-
glass. Other things being equal, the value of a sample is
determined by the amount of impurities present. These im-
purities are ordinary dirt, mucus naturally present inside the
bladder technically called grease, and blood stains. If the
bladderSp were hung up to dry with the orifice downward, the
mucus could be drained off; but usually the fishermen fear
the reduction in weight, and take care to retain all they can.
It is necessary to insist on having the bladders slit up and
rinsed clean as soon as they are removed from the fish. This
would so much increase the value of the product that the
extra labor would be very profitable. Blood stains cannot
be removed without injuring the quality. If any process
could be devised effectual for this purpose, a valuable dis-
covery would be made.
The uses of isinglass are not very varied. The largest
quantity is used by brewers and wine merchants for clarifying.
This property is extraordinary, for gelatin, which seems chem-
ically the same thing as isinglass, does not possess it.
For clarifying purposes the isinglass is " cut " or dissolved
in acid, sulphurous acid being used by brewers, as it tends to
preserve the beer. When reduced to the right consistence, a
little is placed in each cask before sending it out for consump-
tion. *$
There seems to be only six isinglass cutters in England,
all being in London. The sorted isinglass is very hard and
difficult to manipulate. It is soaked till it becomes a little
pliable, and is then trimmed. Sometimes it is just pressed by
hand on a board Math a rounded surface ; at others it is run once
between strong rollers to flatten it a little. The next process
is that of rolling. Very hard steel rollers, powerful and
accurately adjusted, are usedf They are capable of exerting
a pressure of 100 tons. Two areemployed, the first to bring the
isinglass to a uniform thickness, and the smaller ones, kept cool
by a current of water running through them to reduce it to
466
little more than the thickness of writing paper. From the finer
rollers it comes in a beautifully transparent ribbon, many
yards to the pound, " shot " like watered silk in parallel lines
about an inch broad. It is now hung up to dry in a separate
room, the drying being an operation of considerable nicety.
When sufficiently. dried, it is stored till wanted for cutting, or
it is sold as ribbon isinglass to all who prefer this form.
MODERN USES OF TIN.
The uses of tin have greatly increased during the last few
centuries of our era. Salmon, in his splendid work on casting
tin (1788), describes the methods of work, and mentions the
objects manufactured from this metal. We see from the
plates of his atlas that table services (spoons and forks)
pitchers, jugs, candelabra, lamps, surgical instruments, chem-
ical apparatus, boilers for dyeing scarlet, etc., were being put
upon the market in the most varied forms of that epoch.
Griffith, between 1840 and 1850, perfected the manufacture
of tin utensils in a single piece. This industry became espe-
cially developed in France from 1850 to 1860.
In 1860 America began manufacturing impermeable boxes,
without soldering, from single pieces of metal. &>
% To-day tin is being used in the manufacture of bronzes for
guns, money and medals, and in the alloys used for making
measures of capacity for liquids. Its unalterability in the air,
and the harmlessness of its salts when they exist in small
quantity, cause it to be employed in our day in the manufac-
ture of culinary vessels and utensils. Advantage is taken of
its malleability to form from it those tbm sheets that are
used as wrappers for chocolate, tea, etc.
In the various bronzes that it forms with copper, we have
evidence of the influence that relative proportions of the two
metals have upon the properties of the alloy. Thus gun bronze,
which contains ten parts of tin to ninety of copper, is remark-
able for tenacity. The bronze of tom-toms and bells, which
differs from the last named only in its larger proportion of
tin (twenty to eighty of copper) is, on the contrary, very brit-
tle, although it fortunately possesses greater sonorousness
than gun metal does. On still further increasing the propor-
tion of tin to thirty-throe parts per sixty-seven of copper, we
obtain a white alloy capable of taking a polish that causes it
to be used for the manufacture of telescope mirrors. Upon
uniting with tin, copper loses its ductility. The alloys of
these two metals increase in density through being hardened,
as th^y do also by being hammered.
467
A mixture of twenty parts of tin with eighty of copper
gives an alloy which is brittle at a bright red heat and when
cold, but wnich is malleable at a dark red heat.
When alloyed with lead, the tin forms plumbers' solder.
Associated with mercury, it gives the silvering of looking-
glasses. Besides this, it enters into a host of fusible alloys or
compositions, known under the general name of white metal.
One of these alloys, composed of tin, antimony and copper,
is very much used as a bushing for engine bearings. For this
purpose the following are very good proportions: Tin, 100;
antimony, 10 ; copper, 10. It is also alloyed with antimony
alone, or with bismuth. It serves for tinning copper and iron
kitchen utensils. To this effect the wrought-iron utensils
are cleaned with sand and then wiped, and afterward im-
mersed in a bath of molten tin, and finally rubbed with tow
saturated with sal-ammoniac. Food cooked in tin vessels has
a slight fishy taste, because it dissolves a little of the tin, just
as food prepared in iron contracts a slight taste of ink.
Tin is used in enormous quantities also in the manufacture
of tinplate. In order to prepare this, the sheet iron designed
for the manufacture of it is cleansed by plunging into diluted
mlphuric acid, which dissolves the pellicles of oxide. Then
it is rubbed with sand and immersed in melted tallow, and
afterward in a bath of tin covered with tallow. When taken
out it is tinned, there having formed upon the surface of the
sheet iron a true alloy of iron and tin covered with pure tin.
Tin plate is as unalterable a*s tin itself, because the iron does
not come into contact with the air at any point; but if, upon
cutting it, we expose the iron, oxidation proceeds more rapidly
than it would if the iron had not been tinned.
Upon washing the surface of the tinplate with a mixture
of hydrochloric and nitric acids, we remove the superficial
layer,"and render visible the crystallized surface of the tin and
iron alloy. We thus obtain what is called moire metallic or
crystallized tinplate.
It now remains for us to say a few words about the new
and important use of tin for the preparation of phosphor
bronze.
In the melting of bronze the absorption of oxygen is
very detrimental, the formation of an oxide of tin rendering
the metal brittle. In former times an endeavor was made to
prevent this oxidation by stirring the mass with wood, or by
adding a little zinc to it ; but for the last fifteen years
greater success has been obtained by the addition of a little
phosphorus This substance extraordinarily increases the
compactness, toughness and elasticity of the product, and
468
gives it, in addition, a beautiful golden color. Guns,
statues, ornaments and bearings are now cast from phosphor
bronze with the greatest success.
Kunzel, of Dresden, has taken out a patent for an alloy
composed one-half to three parts, by weight, of phosphorus,
from four to fifteen of lead, from four to fifteen of tin, and
for the rest, copper up to 100.
Schiller & Sewald, of Graupen, prepare two kinds of
phosphor brojze; one with 2>^ and the other 5 per cent, of
phospnorus. The demand for this article is daily becoming
more extensive.
The most important uses of tin are, in Asia, for tinning
copper, and in Europe and America, for the manufacture of
objects from tinplate. The manufacture of bronze and
white metal likewise consumes a large quantity.
USES OF MICA.
The peculiar physical characteristics of mica, its resistance
to heat, transparency, capacity of flexure and high electric
resistance, adapt it to applications for which there does not
appear tc be any perfect substitute. Its use in windows,
in tKe peep-holes on the furnaces used in metallurgical pro-
cesses, as well as the ordinary use in stoves for domestic pur-
poses, are examples of its adaptability to specific purposes
which it does not seem to share with any other material. Its
fitness for use in physical apparatus is represented by its
application for the vanes on the Coulomb meter, recently in-
vented by Prof. George Forbes, F. R. S. For electrical
purposes mica has proved useful, acting as an insulator be-
tween the segments of commutators of dynamos and safety
fuses in lighting circuits, also as the base part of switches
handling heavy currents, to obviate the dangers of ignition
by the arc formed when the switch is changed. For this
latter purpose it shares the field with sheets of slate. Both
of these uses were first suggested a number of years ago by an
insurance expert in America in the course of regulations gov-
erning the safe installation of electric-light plants. As a
lubricator, mica answers a veiy peculiar purpose for classes
of heavy bearing, where the powdered mica serves a useful
office in keeping the surface separate, thereby permitting the
free ingress of oil. It is used in roof-covering mixtures in a
powdered condition in combination with coal tar, ground
steatite and other materials, its foliated structure tending to
bond the material together. Not affected by ordinary chem-
icals which are corrosive to many other substances, it has
469
been applied in the valves to sensitive automatic sprinklers,
where a sheet of mica placed over a leather disk has proved
to be non-corrosive, and without possibility of adhering to
the seat, while the leather packing rendered the whole suffi-
ciently elastic to provide a tight joint.
IMPROVED PROCESS OF TINNING.
An improved process of coating metals with tin, by Borthel
and Holler, of Hamburg, is said (by a metropolitan contem-
porary) to possess the advantage of preventing, or at least
delaying, oxidation. The process can be employed with
special advantage for tinning cast-iron cooking utensils,
household and other implements of cast iron, as the employ-
ment of poisonous enamel is avoided and a much higher
degree of polish attained. The process can also be employed
for protecting architectural or other iron decorations from
rusting by the coating of tin or other metal, without detri-
ment to the sharpness of the form, as is the case with the
customary oil or bronze paints. In order to produce a per-
fectly even coating of tin on cast iron, the same is first provided
with a thin coating of chemically pure iron, regardless of the
form of casting. This coating is produced in galvanic man-
ner in a bath composed as follows : Six hundred grammes
of sulphate of iron, FeSO4, are dissolved in five liters of water,
to which add a solution of about 2,400 grammes of carbonate
of soda, Na2CO3, in five liters of water. The precipitate of
ferro-carbonate (FeCo3) resulting is dissolved in small quan-
tities in so much concentrated sulphuric acid until the fluid
has a green color. The bath is then rendered aqueous by
adding about twenty liters of water. Blue litmus paper
dipped in the bath must assume a deep claret color, and red
litmus paper remains unchanged.
> The objects to be provided with a coating of chemically
pure iron are placed in the bath opposite to the abode of cast
or wrought iron or iron ore, and both parts connected to the
Corresponding poles of a dynamo machine, electric battery, or
other appropriate source of electricity. In a very short time
the objects placed in the bath are covered with a coating of
iron, the thickness of which depended on the duration of the
action of the bath or the strength of electric mrrent. $ The
Coated objects are then well rinsed in clear wat /r, dried, then
painted with, or immersed in, a solution c-f ammonia in
chloride of zinc alone, and then immersed v* a vessel contain-
ing molten tin The tin adheres with g>Vat tenacity to the
prepared surface, and the surplus of tin '/an be readily removed
470
by a brush, or any other manner. If the object to be tinned
is of such size, or so complicated in form, that it cannot be
readily immersed in molten tin, it can be placed in a galvanic
tin bath, which can be readily made in any desired size, and
be provided with a layer of tin of desired thickness, which,
after having been painted either with a solution of chloride of
zinc or ammonia in chloride of zinc, can be heated to such a
degree that the tin is equally melted on the object.
In like manner objects cast or made of lead or other
readily melting metal, which would lose their form by melt-
ing when immersed in molten tin, are, previous to tinning,
provided with a coating of pure iron, and are then provided
with a coating of tin in a galvanic bath, as mentioned above,
without being subjected to heat for melting the layer of tin
deposited on the same. With objects of wrought or rolled
iron, or which clo not require the before described treatment
— id est, the production of a coating of chemically pure
iron — it will be sufficient to carefully clean the same and
paint them with a solution of ammonia or chloride of zinc
or a concentrated solution of chloride of zinc. This tinning
process combines the advantage of simple manipulation and
the great durability of the coating with cheapness of manu-
facture, which is partially attained in the saving of tin.
SOLDERING.
The term soldering is generally applied when fusible
alloys of lead and tin are employed for uniting metals.
When hard metals which melt only above a red heat, such
as copper, brass or silver, are used, the term brazing is some-
times used. Hard-soldering is the art of soldering or uniting
two metals or two pieces of the same metal together by
means of a solder that is almost as hard and infusible as the
metals to be united. In some cases the metals to be united
a»e heated, and their surface united without solder by flux-
ing the surfaces of the metals. This process is then termed
burning together. Some of the hard-soldering processes are
often termed brazing. Both brazing and hard-soldering is
usually done in the open fire on the brazier's hearth."*^ A
soldered joint is more perfect and more tenacious as the
point of the fusion of the solder rises. Thus, tin, which
greatly increases the fusibility of its alloys, should not be
used for solders, except when a very easy-running solder is
wanted. Solders made with tin are not so malleable and
tenacious as those prepared without it. The Egyptians sol-
dered with lead as long ago as B. C. 1490, the time of Moses.
Pliny refers to the art, and says it requires the addition of
tin to use as a solder. The tin came mainly from the Cas-
siterides (Cornwall). Plumbers use solder composed of two
parts of lead and one of tin, and a very slight variation in
the quantities makes a very considerable difference in the
working and also in the soundness of the joint. If a slight
excess over the above proportion of lead is used, the soldef
is more difficult to work, and the joint when made fre-
quently leaks, the water passing through the small cellules o*
pores in the metal, and the joint is then said to " sweat." If
an excess of tin is used, the solder melts too easily, and con«
siderable difficulty is found in keeping it on the joint, and it
cools so suddenly that the joints always look rough and
ragged at the ends. They sometimes require trimming up to
make them look better ; this solder also keeps running, an<?
then congealing, in such a way as to be difficult to keep
it at a workable heat Small portions of the metal also
keep sticking to the cioth used for molding (technically
called wiping) the joint or seam as the case may be.
Plumbers' solder, with the above proportions, on being
melted, and then allowed to cool, will generally exhibit sev-
eral bright spots on its surface, due to the two metals partly
separating. These bright spots are generally a very sure
guide as to the proper quantities of each metal used. If
none are seen, it is too coarse; and if too many are seen, it
contains too much tin and is said to be too fine. If the spots
are small the metal may not be good, although it may have
beyond its proper quantity of tin; but if the spots are about
the size of a threepenny piece the solder very rarely fails to
work well. In uniting tin, copper, brass, etc., with any of
the soft solders a copper soldering-bit is generally used. This
tool and the manner of using it are well known. In
many cases the work may be done more neatly without the
soldering-bit by filing or turning the joints so that they fit
closely, moistening them with the soldering fluid described
hereafter, placing a piece of smooth tin foil between them,
tying them together with binding wire, and heating the
whole in a lamp or fire till the tin foil melts. Pieces of brass
are often joined in this way so that the joints are invisible.
With good soft solder almost any work may be done over a
spirit lamp, or even a candle, without the use of a soldering-
bit. Advantage may be taken of the varying degrees of
fusibility of solders to make several joints in the same piece
of work. %• Thus, if the first joint has been made with the
fine tinners' solder, there would be .no dangej^pf melting it
in making a ioint near it with bismuth solder: The fusibil-
472
jty of soft solder is increased by adding msmuth to the com-
position. An alloy of lead 4 parts, tin 4 parts, and bismuth
i part, is easily melted; but this alloy may itself be soldered
with an alloy of lead 2 parts, bismuth 2 parts, and tin r part.
By adding mercury a still more fusible solder can be made.
Equal parts of lead,bismuth and mercury, with two parts of
tin, will make a composition which melts at 122 degrees
Fahr. ; or an alloy of .tin 5 parts, lead 3 parts, and bismuth
3 parts, will melt in boiling water. In melting these solders
melt the least fusible metal first in an iron ladle, then add the
others in accordance with their infusibility. It is convenient
— and in fact, often necessary — to hare solders which will
melt at different degrees of temperature, to avoid the risk of
spoiling the work by subjecting it to too great a heat, when,
with a little easy-flowing solder, there would be no danger.
POINTS ON SOLDERING.
For tinning soldering coppers nothing is bettev than a
soft -burned brick to contain the tin and solder. Dig a cavity
on the side two or three inches long, and wide enough to
receive the soldering tool. Melt some solder in the cavity thus
formed, and throw in some pieces of sal-ammoniac and rosin.
See that the copper bits are hot enough to melt solder ; a
great heat will not tin as well as a low one. Rub the tool
om the brick, melting the solder, ammoniac and rosin. The
trick scours the copper bright, and the flux causes the solder
to adhere very easily. One of the worst things ever
attempted is to solder a dirty job with a dirty, untinned
copper.
See that the surfaces to be soldered are clean. If not,
make them so by filing or scraping ; then protect the surfaces
from oxidation by an application of flux or muriatic acid in
which zinc has been dissolved. Have the soldering copper
hot. Hold it two inches from your face, and the right
degree of heat will soon be learned. When all of these
conditions exist, the melted solder will flow along the seam
with the greatest ease, leaving a smooth, well-finished surface
behind it. •* >
To do work in the best manner and the easiest, a flux
should be provided for each metal to be soldered. The
hydrochloric (muriatic) acid and zinc flux is worthless when
rust is to be avoided, for in some cases the acid continues
to act after the soldering is done, and in a few months may
eat far enough to separate the solder from the work, la
this case, of course, the joint falls apart.
473
In soldering zinc some use muriatic acid diluted with
water for a flux, and the rusting action is to be feared in
this instance, but may be lessened by adding soda carbonate
(washing soda) to the acid. There are few pieces that can-
not be soldered without the use of an acid flux, and rosin
will do nearly as well if a little oil be added, or if the solder-
ing copper be dipped in acid and then into oil before apply-
ing it to the seam with rosin on it.
Sal-ammoniac is the proper flux for copper, and this
agent works well with tin, but it is not necessary, for rosin
is all that is needed. Lead is perfectly fluxed by tallow (the
plumbers call it " touch "), but may be soldered with either
of the other fluxes.
NEW METHOD OF BRONZING IRON.
The following method is successful in producing a bronze-
like surface which practically prevents rust. All the
methods as yet known for producing a bronze-like surface, by
rubbing over the surface of the iron an acid solution of cop-
per or an iron solution, letting it dry in the air, brushing off
the rust produced in this way, and an abundant repetition of
this method, give a more or less reddish-brown crust or rust
on the iron body. Objects formed of iron can easily be
covered with copper or brass by dipping them in the requisite
solution, or by submitting them to the galvanic method. The
surface so prepared, however, peels off in a short time, by
exposure to moist ajr in particular. By the method given
below it is possible to cover iron objects, especially such as
have an artistic aim, with a fine bronze-like surface ; it resists
pretty satisfactorily the. influence of moisture, and one is,
moreover, enabled to apply it to any object with great ease.
The clean, polished objects are to be exposed to the action of
the vapors of a heated mixture of hydrochloric acid and
nitric acid, in equal portions, for from two to five minutes;
they are not to be shifted, and the temperature may range
from 300° to 350° C. The heating is continued so long that
the bronze-like surface is well developed on the surface of the
objects. After the objects have cooled they should be
well ruboed down with vaseline and again heated until the
vaseline begins to decompose. When again cold they should
be a second time treated with vaseline in the same way. If
the vapor of a mixture of the twro concentrated acias is
allowed to act on an iron object in this manner, a light red-
dish-brown tone is developed. If some acetic acid be mixed
with the two acids, and the vapor of all the acids together be
474
allowed to act On the metallic surface, a fine bronze yellow
color can be obtained. By using different mixtures of these
acids every tint, from a dull red-brown to a light brown, and
from a dull brownish yellow to light brown yellow, can be
produced on the surface of the iron. In this way some
T-rods for iron boxes were covered with a bronze-like surface,
and at the end of ten months, although exposed during the
whole time to the action of the acid fumes of a * bnratory,
they had undergone no trace of any change.
MAN JFACTURE OF RUSSIAN SHEET IRON.
There appears to be much misunderstanding in reference
to the manufacture of sheet iron in Russia, and questions
are frequently asked the writer : " What are the secrets con-
nected with it ? " " How is it made ? " " Could admission be
obtained to the iron works in the Urals, where the iron is
made?" It is difficult to understand why such questions
should be asked by persons versed in the literature of
iron and steel, for Dr. Percy wrote a very excellent and
accurate monograph on the subject a number of years ago.
Not having had the opportunity of personally visiting the
Russian iron works in the Urals, Dr. Percy's paper was com-
piled from data furnished him by a number of persons who
had actually visited these sheet iron works. Since it has
been my good fortune to have the opportunity of seeing
some of these works in the Urals, but a short time ago, I
will, at the risk of telling an old story, briefly describe the
process of manufacture as I saw it.
The ores used for the manufacture of this iron are mostly
from the celebrated mines of Maloblagodatj, and average
about the following chemical composition: Metallic iron,
60 per cent. ; silica, 5 per cent. ; phosphorus from o. 15 to 0.06
per cent. The ore is generally smelted into charcoal pig
iron, and then converted into malleable iron by puddling or
by a Franche-Comte hearth. Frequently, however, the
malleable iron is made directly from the ore to various kinds
of bloomaries.
The blooms or billets thus obtained are rolled into bars 6
inches wide, % inch thick and 30 inches in length. These
bars are assorted, the inferior ones " piled " and re-rolled,
while the others are carefully heated to redness and cross-
rolled into sheets about thirty inches square, requiring from
eight to ten passes through the rolls. These sheets are twice
again heated to redness, and rolled in sets of three each, care
being taken th t every sheet before being pas?ed through the
475
rolls is brushed off with a wet broom made of fir, and at the
same time that powdered charcoal is dextrously sprinkled
between the sheets. Ten passes are thus made, and the
resulting sheets trimmed to a standard size of twenty-five to
fifty-six inches. After being sorted and the defective ones
thrown out, each sheet is wetted with water, dusted with
charcoal powder and dried. They are then made into pack-
ets containing from sixty to one hundred, and bound up with
waste sheets.
The packets are placed one at a time, with a log of wood
at each of the four sides, in a nearly air-tight chamber, and
carefully annealed for five or six hours. When this has been
completed the packet is removed and hammered with a trip-
hammer weighing about a ton, the area of its striking surface
being about six to fourteen inches. The face of the hammer
is made of this somewhat unusual shape in order to secure a
wavy appearance on the surface of the packet. After the
packet has received ninety blows, equally distributed over its
surface, it is reheated and the hammering repeated in the
same manner. Sometime after the first hammering the packet
is broken and the sheets wetted with a mop, to harden the
surface. After the second hammering the packet is broken,
the sheets examined, to ascertain if any are welded together,
and completely finished cold sheets are placed alternately
between those of the packet, thus making a large packet of
from 140 to 200 sheets. It is supposed that the interposition
of these cold sheets produces the peculiar greenish color that
the finished sheets possess on cooling.
This large packet is then given what is known as the
finishing or polishing hammer ing. For this purpose the trip-
hammer used has a larger face than the others, haying an
area of about 17 to 21 inches. When the hammering has
been properly done the packet has received 60 blows, equally
distributed, and the sheets should have a perfectly smooth,
mirror-like surface. The packet is now broken before cool-
ing, each sheet cleaned with a wet fir broom to remove the
remaining charcoal powder, carefully inspected, and the good
sheets stood on their edges in vertical racks, to cool. These
sheets are trimmed to regulation size (28 by 56 inches) and
assorted into Nos. i, 2 and 3, according to their appearance,
and again assorted according to weight, which varies from
10 to 12 Ibs. per sheet. The quality varies according to color
and freedom from flaws or spots. A first-class sheet must be
without the slightest flaw, and have a peculiar metallic gray
color, and on bending a number of times with the fingers,
very little or no scale is separated, as in the case of
476
ordinary sheet iron. The peculiar property or Russian sheet
iron is the beautiful polished coating of oxides ( ' glanz")
which it possesses. If there is any secret in the process, it
probably lies in the " trick " of giving this polish. As far as I
was able to judge, from personal observation and conversa-
tion with the Russian iron masters, the excellence of this
sheet iron appeared to be due to no secret, but to a variety of
conditions peculiar to and nearly always present in the
Russian iron works of the Urals. Besides the few partic-
ulars already noted in the above description of this process, it
should be borne in mind that the iron ores of the Urals are
particularly pure, and that the fuel used is exclusively char-
coal and wood. Another and equally important considera-
tion lies in the fact that this same process of manufacturing
sheet iron has been carried on in the Urals for the last hun-
dred years. As a consequence, the workmen have acquired a
peculiar skill, the want of which has made attempts to manu-
facture equally as good iron outside of Russia generally
unsuccessful. It is difficult to understand what effect the use
of charcoal powder between the sheets, as they are rolled and
hammered, has upon the quality. It is equally as difficult to
understand the effect of the interposition of the cold-finished
sheets upon the production of the polished coating of oxide.
The Russian iron-masters seem to attribute the excellence of
their rroduct more to this peculiar treatment than to any
other cause. One thing is 'quite certain, there is no secret
about the process, and if the Russian sheet iron is so much
superior to any other, it is due to the combination of causes
already indicated.
THE LARGEST ELECTRIC LIGHT IN THE
WORLD.
The largest electric light in the world is on St. Catharine's
Point lighthouse, Isle of Wight. Some idea of the power of
this light will be conveyed when it is known that the carbons
employed in electric arc lamps commonly used for street
lighting are about ^ inch in thickness, while these have a
diameter of nearly 2^ inches.
There are two dynamos, and if both worked in conjunc-
tion it is computed that the concentrated light from the
lantern would equal six millions of candles. The induction
arrangement of each machine consists of sixty permanent
magnets, and each magnet is made up of eight steel plates. The
armature, 2 ft. 6 in. in diameter, is composed of five rings with
twenty-four bobbins in each, arranged in groups of four in
tension and six in quantity.
477
LUMBER MEASUREMENT TABLE.
LENGTH
LENGTH
LENGTH
LENGTH
LENGTH
LENGTH
2X4
2x6
2x8
2XIO
3X6
3*8
12 8
12 12
12 l6
12 20
12 18
12 24
14 9
14 14
14 19
H 23
14 21
14 28
16 ii
16 16
16 21
16 27
16 24
16 32
18 . 12
18 18
18 24
18 30
18 27
18 36
20 13
20 20
20 27
20 33
20 30
20 40
22 15
22 22
22 29
22 37
22 33
22 44
24 ID
26 17
24 24
26 26
24 32
26 35
24 40
26 43
24 36
20 39
24 48
26 52
3\IO
3X12
4x4
4x6
4x8
6x6
12 30
12 36
12 l6
12 24
12 32
12 36
H 35
14 42
14 19
14 28
H 37
14 42
16 40
16 48
16 21
16 32
16 43
16 48
18 45
18 54
18 24
1 8 36
18 48
18 54
20 50
20 60
20 27
20 40
20 53
20 60
22 55
22 66
22 29
22 44
22 59
22 66
24 60
24 72
24 32
24 48
24 64
24 72
26 65
26 78
26 35
26 52
26 69
26 78
6x8
8x8
8xio
IOXIO
10X12
12X12
12 48
12 64
12 80
12 100
12 120
12 144
H 56
H 75
H 93
14 117
14 140
14 168
16 64
16 85
16 107
16 133
16 160
16 192
18 72
18 96
18 120
18 150
18 180
18 216
20 80
20 107
20 133
20 167
20 2OO
20 240
22 88
22 117
22 147
22 183
22 220
22 264
24 96
24 128
24 1 60
24 200
24 240
24 288
26 104
26 139
26 173
26 217
26 260
26 312
A blast at 800 degrees temperature will ignite charcoal ;
900 degrees will ignite coke, and 1,300 degrees will ignite
anthracite.
478
THE DYNAMO.
HOW MADE AND HOW USED.
The interest awakened in machines for the generation of
current electricity, consequent upon the demand for electric
lighting and transmission of power, has induced many
amateurs to turn their energies to the construction of small
dynamos, such as might replace a battery of eight or ten
cells, without the disagreeable features of changing acids,
cleaning plates, etc. Such efforts have not generally met
with success, owing to the fact that no work of a practical nat-
ure has yet appeared in which the construction of the
dynamo is fully explained. When the principles which con-
trol the manufacture of such machines is understood,
dynamos can be constructed with as much ease and cer-
tainty as induction coils.
§ i. What a Dynamo is. — As understood at present, the
dynamo-electric machine may be defined as a machine
whereby energy (motion) is converted into electricty by the
aid of the permanent magnetism present in certain iron por-
tions: which electricity is caused to react on the iron and so
heighten its magnetism; and this increased magnetism in its
turn gives rise to more powerful electrical effects, and so on,
until a limit is reached, depending partly on the velocity of
the motion, partly upon the relative apportionments of the
size and quality of the wire and iron employed in its con-
struction, and partly on the resistance throughout the cir-
cuit. ^Although this principle was fully understood, and de-
scribed by Soren Hjorth, of Copenhagen, in his patents, dated
October, 1854, and April, 1855, yet the name "dynamo" (from
dynamisy Gr., force] does not appear to have been used in
this connection until Dr. Werner Siemens employed it in a
communication to the Berlin Academy, January 17, 1867.
§ 2. Faraday"1 s Discovery. — The closeness of the relation-
ship between the phenomena which we call electricity and
magnetism had struck many philosophers of the eighteenth
century. Oersted, of Copenhagen, in 1819, was the first to
prove, by a series of masterly experiments, the magnetic
properties of current electricity; Ampere and Arago, in
France, and Sir Humphry Davy in England, then distin-
guished themselves by their zeal and activity in this research;
but the keystone of the arch was laid when Faraday, in
November, 1831, showed that it was possible to call forth
electric currents by means of a magnet. In order that the
479
reader should have an intelligent knowledge of the principles
which underlie the construction of the dynamo, it would be
well for him to repeat some of the experiments about to be
described, more especially as they are easy of performance
and trifling in cost.
The first thing required will be a galvanometer, an
instrument for indicating the presence of current electricity
(and in some cases to measure its quantity). To make this,
a piece of spring steel, 2 inches long and y& of an inch in
width, is "softened" by heating the middle portion over a
gas jet or other flame, until red hot, then allow to cool
gradually. By laying this across a knife blade the exact
center is found and marked. By means of a screw-arill a
hole about -3\> of an inch diameter clear through the center
of this steel "needle," as it is
called, is bored. By filing from the
center toward the side the needle
is brought to the shapev of a
lozenge, as seen at Fig. i, A.
Holding this needle by means of a
piece of copper wire passed
through the hole, it is heated to
dull redness over a flame and
plunged into cold water to restore
its temper. A piece of brass rod,
y% of an inch in diameter, and
about y% of an inch long, is now
soldered centrally, just over the
hole. This is easily done by
cleaning the needle with a bit of sandpaper, specially
round the hole, cleaning also the little piece of brass
rod, on its end, then putting a little piece (as big as a grain
of mustard-seed) of plumbers' solder just over the hole bored
in the needle. Holding the needle with a pair of forceps (a
little rosin powder having been previously applied roundabout
the hole) over the flame of a spirit-lamp or gas-burner, wil1
cause the solder to melt and adhere to the steel. The piece
of brass is now taken up with another pair of forceps, and
laid (flat side downward) as centrally as possible over the
hole. Keeping the needle still over the flame, the solder
will also flow round the brass and adhere to it, making a firm
junction, when it may be removed from the flame, and placed
at once on a cold metal or stone surface. It should now
present the appearance shown at Fig. i, B. Any solder
which may have exuded from between the brass and steal
should be filed away. Using the same bit in the screw-drill
that was employed originally to bore the hole through the
steel, a conical hole, reaching nearly but not quite to the
opposite surface of the brass piece, is drilled from the hole in
the steel. This serves as a pivot on \vhich to poise the needle.
A trial may now be • made to find whether the needle
is fairly centered; but no attempt need be made yet to balance
it if not true. Having cut off the head of a fine-pointed pin,
drive it, blunt end downward, into the center of a little slab
of well-seasoned pine 3 inches by 3 inches by }< an inch,
leaving not less than % of an inch protruding. On the point
poise the needle, and mark with a pencil the end which
hangs (if either does). Fig. i, C, will show what is meant.
The needle must now be magnetized by being allowed to
remain for some tiiue (twenty minutes or half an hour) across,
and in contact witL. the poles of a horse-shoe magnet, care
being taken that having once placed the needle in one position
' it should not be reversed, as its polarity would be reversed
if this were done; and since in our latitude the north-seeking
pvle of a freely suspended needle Jiangs downward, if the needle,
when tried previous to magnetizing, had one end heavier than
the other, ///<?/ end must be placed against the north pole of the
horse-shoe imgnet, by which means it will acquire south-seek-
ing polarity, and consequently neutralize to a certain extent
the inclination of the poised needle. After magnetization
it should be again poised, any deviation from the horizontal
line noted auxi corrected by cautiously filing the needle on
one of its flat sides, at its heavier extremity, with a fine file,
until perfect equilibrium is obtained. Fig. i, D, illustrates
the position in which the needle should be placed with rela-
tion ta the magnet during magnetization. When the needle
has betu mrell balanced it ought to turn very freely on its
pivot, making several free swings, but finally taking up a
position pointing norfh and south. It should also show de-
cided polarity when tested with a magnet; that is to say, one
extremity should be strongly attracted, and the other just as
stron iy repelled on the approach of the north pole of a
horso-shoe or bar magnet. When all these conditions have
been satisfied, it will be well to mark with a pencil the letter
N on the extremity of the needle, which is repelled by the
north -seeking (or marked) end of the magnet. This extrem-
ity will be the north-seeking end of the needle, and is gener-
ally (though inaccurately) called its north pole.
$ 3. We have now succeeded in making and poising a
magnetic needle. In so doing we have learned two impor-
tant facts: (a) that steel becomes permanently magnetic
when placed in proximity to a magnet; (b) that each pole of
the new magnet thus formed evinces a polarity of opposite
kind to that possessed by the pole of the original magnet
which induced its magnetic condition; in other words, the
north pole of the original magnet induces south polarity in
that portion of the steel nearest to it, while the south pole
induces north polarity.
Our next step is to surround the needle with a coil of in-
sulated copper wire. To this end a piece of wood 2^ inches
wide by i^ inches thick, and of convenient length to hold in
the hand, is prepared as a form, the edges being slightly
rounded to admit of the wire being
slipped off; this is then wound
with about ten feet of No. 30 silk-
covered copper wire, as shown at
Fig. 2, A, leaving about three
inches of wire projecting at each
extremity, The four corners of
the rectangle thus formed should be bound with silk, so as to
prevent uncoiling when the rectangle is drawn off the wooden
form. The coil, on removal from the form, should present
the appearance shown at B, in which the ends of the silk
used to tie the corners are purposely exaggerated in length,
the better to show their position. The center of the coil
being found, the wires forming one of the
flat sides are slightly parted by means of
a blunt pin (care being taken not to abrade
the silken covering), and the coil passed
over the pin-point fastened in the center
of the little baseboard above described
(§ 2), and attached thereto with a little
dab of hot sealing-wax, or, better still, with good elastic
cement. The needle is then replaced, and tried, to see
whether it "oscillates freely without catching at any point in
the coil. The two free ends of the wire are now to be de-
nuded of their silk covering, cleaned with a bit of sand or
flass paper, and attached to two small binding screws (those
nown as telephone binding-screws, and sold at most elec-
482
tricians' at 50 merits per dozen,
will do admirably), inserted
one at each corner of the base-
board. The galvanometer or
multiplier is now complete,
and should appear as figured at
C. When all is in position,
note from which binding-screw starts the wire which goes
over the needle. Mark this binding-screw by writing rt over "
near it. The galvanometer is used to detect the presence of
current electricity by causing any such current to pass
through the coils of the instrument. For this purpose the
two opposite extremities of any circuit, through which it is
supposed a current is flowing, are each connected to one of
the binding-screws. If a current passes, the needle (which
previously must be made to lie parallel with the coil, by
turning the baseboard round until the coil points north and
south, like the needle) will immediately start out from its
position of parallelism with the coil, and take up a position
which will approach nearer to right angles with the coil, in
proportion as the current is stronger. To test whether the
galvanometer just made be fairly delicate, attach a piece of
copper wire about ^ of an inch thick and six inches long to
one of the binding-screws; to the other attach a similar piece
of iron wire. Now bring the free ends of the wire (by bending)
within l/% of an inch of each other. Turn the baseboard round
until the north end of the needle points between the two
binding-screws, perfectly parallel to the coil. Put a single
drop of vinegar on a little piece of glass, and bring it under
the two ends of the wires, which must be lowered until
they are both in the drop of vinegar, but do not touch
each other. By the action of the vinegar on the two
metals, an electrical disturbance is set up, which produces a
so-called" current " which starts from the iron; passes through
the vinegar, along the copper wire, through the coils of the
galvanometer, and back again into the iron, this action being
continuous as long as the vinegar acts on the iron. Simulta-
neously with this, the needle is seen to deflect from the line
of the coil, and if our galvanometer LG a success, it should
stand out at least 20° from the centrai line of the coil. Far-
aday's great discovery, on which all dynamos are based, con-
sisted in proving that a magnet could be caused to excite a
current, similar to that produced by the action of acids on
metals. We can now repeat his experiment
with the aid of our galvanometer. Let A,
Fig. 3, be a rod of % inch soft iron, about
6 inches long, bent to the shape of the letter
U, and wound round its central portion with
about 100 feet of No. 24 cotton-covered
copper wire, the two ends of which (about a
yard each end) having been stripped of their
covering, must be attached to the binding-
screws of the galvanometer. If a good horse-
shoe magnet, B, be placed in contact with
the two legs of the coiled U, this latter being
kept motionless, while the magnet is alter-
nately approached to and separated from
it, it will be found that the needle of the
galvanometer is powerfully affected, first in
one sense and then in the other, according
to whether we make, or break contact with
the U, or armature ', as it is called. We shall
also find that, although the most powerful
effects are noticed when actual contact and
actual separation take place, yet currents are
also produced on approaching or removing
gnet to or from a distance. In other words, motion
field of a magnet gives rise to electricity. If we study
the effects thus obtained, we shall find that they differ in
some points very markedly from those obtained by the action
of acids on metals (voltaic electricity — galvanism), inasmuch
as first, the action is not continuous ; secondly, it is contrary
in direction when contact is made to what it is when it is
broken.
§ 4. The student will do well to compare the effects pro-
duced on the galvanometer by the battery current, and by the
current obtained from the magnet. Any single cell will
do for this purpose ; and in order to have an intelligent per-
ception of what takes place, the student must bear in mind,
that in the battery itself, the electricity (undulatory move-
ment of the molecules) passes from the zinc to the negative
plate (be it copper, silver, platinum, or graphite), while out-
side the battery, the electricity passes from this latter round
through the wires, galvonometer, or other circuit open to its
passage, back again to the zinc plate. (See Fig. 4, where the
direction of the undulation, or "current, "is shown by the
arrows ; the plate marked Z being zinc, the one marked C
being carbon, copper, or other conductor ; W W being the
wires forming the /<?/£$• or electrodes. ) If the positive pole (the
one from which the /'current " is flowing, the wire attached
to the C plate) of such a battery be connected to the galva-
nometer by means of the binding-screw marked " over," the
other pole being attached to the other binding-screw, the north
pole of the needle having previously been adjusted so as to lie
between the two binding-screws, it will be found that the
north pole of the needle will deflect to the left of the
line of the coil ; the operator being sup-
posed to be standing at the binding-screw
end of the galvanometer. Since the wire
of our coil returns below the needle, it
is evident that a positive current (an out-
flow of undulation) passing over the north
pole of a horizontally suspended needle,
of a negative current (an influx of undula-
tion) passing under such a north pole,
causes it to deflect to the left.
If we disconnect the battery and reverse
the connections — that is, join the negative
pole (the wire coming from the zinc) to the
binding-screw marked " over, " the other pole
being connected to the other screw — the
opposite effect results, viz., the north pole
now deflects to the right of the coil. This
will be understood by reference to Fig. 5, in
which a represents the effect of the positive
current flowing/>ww the operator over the
needle, the north pole in both illustrations
being nearest to him ; in b the positive
current is supposed to be flowing from the operator, below
the needle, in either case returning to the battery the oppos-
ite way.
§ 5. The effect will enable us at once to recognize, by
means of our galvanometer, the direction in which a current
is traveling; for, on connecting the two terminals of any
source of electricity to the binding-screws of the galvanom-
eter, ..while the north pole is in a line with the coils, be-
tween the two binding-screws, the operator facing the north
pole of the needle, it is evident that if the north pole
of the needle is deflected to the left, the terminal at-
485
tached to the binding-screw marked " over " is positive; but
that if the north pole deflects to the right, then the said
terminal is negative. It must be borne in mind that by the
term positive in this connection is meant the point from
which electricity is flowing, negative being the point toward
which it is flowing, or at which it enters. This power of
NO. C.
r
recognizing the direction of a current will be found of great
service to us in the construction of the dynamo.
§ 6. Returning now to our experiments with the magnet
(see latter portion of § 3), and using in preference a straight
soft iron rod, about 6 inches in length and J^ inch in diameter,
coiled with about loo feet of No. 24 covered wire as pur
armature, and a good bar magnet to produce the electrical
effects, we shall find, on coupling up the armature wires to
the galvanometer, and approaching one end of the armature
to or receding it from the north pole of the magnet, that the
-electrical flow set up is always in one direction in approach-
ing or making contact, and in the opposite direction on re-
ceding or breaking contact. Fig. 6 will make this clear.
The arrow at a shows the direction of the current produced
on approaching or making contact with the north pole of a
magnet; b illustrates the direction of current produced on
receding from or breaking contact with the north pole of a
magnet. If now we reverse the experiment by presenting the
south pole of the magnet to the coiled armature, we
shall find that the direction of flow is also reversed; that is
to say, the withdrawal of a south pole produces the same
effect as the approach of a north pole, and vice versa, the
approach of a south pole is equivalent in its effects to the
recession of a north pole. It must be noted that the direction
in which the wire is coiled round the soft iron rod (or arma-
ture), while it has no influence on the direction of the elec-
trical ctorrent set up round the iron rod (which is always the
reverse to the hands of a clock in the face approaching the
north pole) determines the extremity of the said wire at
which the current leaves or enters the coil. In the figure
we have supposed the wire to be wound from left OVER
toward right ; had we wound our rod from left UNDER
toward right, the opposite ends of the wire would have been
respectively + and — . This must be borne in mind when we
proceed to actual work.
§ 7. Currents can produce Magnetism, — If we take the
coiled soft iron U, of which we made use § 3, and apply it to
pieces of soft iron, nails, filings, etc., we shall find that it
possesses little or no magnetic power of attraction ; but if
we couple the projecting ends of the coiled wires one to each
terminal of a single-cell battery, we shall find that the U will
become powerfully magnetic, retaining its magnetism as long
as electricity flows around the coils, but losing nearly all the
instant that the flow is caused to cease, either by breaking
connection with the battery or by any other interruption.
The rapidity and completeness with which the iron loses its
magnetism depends almost entirely on its softness and purity.
Anything which tends to put a strain on the molecules of the
iron, such as hammering, filing, twisting, sudden cooling,
vibration, etc., render it liable to retain magnetism, or
increase its coercitive force ; whereas raising to a high tem-
perature and very gradual cooling, which allows the mole-
cules to range themselves with little or no strain, furnishes a
soft iron, eminently incapable of retaining magnetism, or
possessing little coercitive force.
$ 8. The direction, in which the flow of electricity
takes place around the iron bar decides which end of the
bar acquires north-seeking, and which south-seeking po-
larity. Let us suppose as in Fig. 7> A, that one ex-
tremity of the bar be made to face us, and that the
current be caused to flow in the direction of the motion
of the hands of the clock; in this case, the farther ex-
tremity of the bar becomes a north-seeking pole, while the
nearer extremity becomes south-seek-
ing. The direction of the current,
and consequently the polarity of the
bar, may be reversed by joining up
the opposite electrodes cf the battery
(or other source of electricity) to the
ends of the wire coiled round the bar,
as shown at B; where, as the wire is
joined to the electrodes in a manner
just the reverse to that shown at A,
so also the current enters at the op-
posite end of the wire, and produces
I\J» contrary magnetic effects. The same
i result may also be attained by coiling
I the wire around the bar in the con-
trary direction, while leaving the
connection with the electrodes un-
changed, as represented at C (Fig. 70). Perhaps the simplest
means of remembering the relation
which exists between the direction of /«? r*
the current and the position of the
magnetic poles produced, is one known
as " Ampere's Rule," in which the ex-
perimenter considers himself to be
swimming head foremost, •with the
current, along the wire, always facing
the iron core; then the NORTH-SEEK-
ING POLE will always be at his LEFT HAND. (See Fig. 8).
§ 9- It must be borne in mind, as
being of the greatest importance in
the construction of successful dyna-
mos, that although steel, or hard
iron, when subjected to this induc-
ing action of the current, becomes
magnetic, yet it does not acquire
nearly such powerful magnetism as
soft iron; and, in fact, the softness
of the iron, and its capacity for be-
coming powerfully magnetic, run side by side. On the other
hand, it must not be forgotten, as we learned at § 7, that the
softer the iron the sooner it loses the magnetism imparted to
it; while the harder brands of iron (and more especially steel)
retain nearly all the magnetism which it is possible to confer
upon them.
§ 10. The student who has carefully and intelligently
performed the experiments described in the previous sec-
tions, will now find himself in a position to understand the
principles which underlie the construction of the dynamo,
even though he may have little or no previous knowledge of
electricity. ^The first machine constructed after Faraday's
discovery was that of H. Pixii, in 1832. In this machine
a powerful horse-shoe magnet was caused to rotate rapidly
before a soft iron U-piece, wound with insulated cop-
per wire, the two extremities of which were prolonged by two
brass springs pressing against a rotating split collar of brass,
whose office was to rectify the direction of the currents pro-
duced by rotation of the magnet, before the iron core; cur-
rents which, as we have set. (^ 4), are in different directions,
according to \vhether a given pole of a magnet is approaching
to or receding from the core. This arrangement for causing
alternating currents to flow in one direction, is known as
the commutator, and it, or some modification of it, is most
extensively used in all dynamos in which it is of importance
that the current should flow in one direction only. The
chief disadvantage in this machine was that of having to
rotate a heavy magnet (built up of a number of thin steel
plates), since the mere rotation tended to destroy, or at all
events, to weaken its magnetism. In 1833 Mr. Sexton had
the happy idea of fixing the heavier and causing the lighter
portions of the apparatus to rotate: in other words, the
magnet (or magnets) was now made a fixture, while the U-
shaped soft iron armature, with its surrounding coils of wire,
was caused to rotate rapidly before it, on axis or spindle,
either by gear-wheels or wheel and band. Mr. E. M. Clarke,
in 1834, noticed that the thickness of the wire coiled round
the armature had a considerable influence on the nature of
the current produced by these machines. If the wire em-
ployed be very thin, say about the TJC of an inch in diameter,
and a large number of convolutions be coiled around the
legs of the armature, the electricity produced is of high
tension, capable of overcoming considerable resistances, and
of giving severe shocks. If, on the contrary, a smaller
quantity of a much thicker wire, say from the ^ to the ^
of an inch be made use of, the current produced is that
Renown as a quantity current, o^ a " large " current, p< s^ess-
ing but little power of overcoming resistances, not capable
of giving shocks, but giving fine large sparks, and able to de-
compose water, and other chemical bodies. ^Clarke usually
furnished two armatures with his machines, one wound with
about 1, 500 yards of covered wire /g of an inch in diameter,
which he designated the " intensity " armature; the other,
wound with about 40 yards of wire Tl8-of an inch thick, to which
he gave the name of the " quantity " armature. One pecu-
liarity of the machines turned out by Clarke was the fact o£
the rotating U-shaped armature being made to rotate near
the flat sides of the magnet instead of in front of the poles.
This, though it facilitates somewhat the mechanical arrange-
ments, is open to some objections
on the score of lesser efficiency, since
the most active portion of the mag-
net is certainly in front of the poles.
As Clarke's machine embodies near-
ly all the principles found in later
dynamos, we shall give an illustra-
tion, together with detailed explana-
tion of the commutator, etc., in our
next paragraph.
§ Ii.^ In Clarke's machine the
horseshoe magnet, A, Fig. 9, is
clamped to a rigid backboard, which
is mortised to the baseboard. In
front of this magnet, and in close proximity to its poles, is the
armature B B', which can be made to rotate on its axis at
<?9 which passes right through the backboard, behind which
49°
k is supported on bearings. The distant end of the axis is
fitted with a pulley, around which plays a band or gut coming
from the fly-wheel / On turning the handle of /, the
small pulley enters into rotation, carrying with it the
armature. This armature (which represents the U -piece
described at $ 3, Fig. 3) is really constructed of three
pieces of very soft iron, two short
circular bars and a cross-piece, held
together by screws, as shown at b.
Around the two bars is carefully
coiled the insulated* copper wire,
in such a manner that, if the bars
were straightened out, the winding
would be always in one continuous di-
rection,either from left over to right ^
or vice versd, and the two extreme
ends of the wire are brought out
and joined metallically with the two
metal half-cylinders which form the
commutator c. This commutator
is illustrated more fully at Fig. 10
i Against the commutator press the two brass springs <
</', to which are connected the wires e and <?', which form the
real electrodes or poles of the machine. Fig. lo shows how
the wire is wound round the two soft iron cores B and B', which
are screwed to the soft iron cross-piece at A and A', thus con-
stituting virtually a coiled U-piece. The two ends of the
wire which forms these bobbins come out at opposite sides of
the bobbins, and are soldered or screwed to the naif -cylinders
(of brass) c and c', as shown at b and b '. In order that the
two cheeks of the commutator, c and c' (which are shown sep-
arately to the right-hand of Fig. 10), should not allow the
electricity to escape from one to the other, the spindle which
carries the bobbins B B' and the cross-piece A A', is encased
in a thick ring of ivory, baked boxwood or other insulator,
which in the illustration is shaded darkly.
FUNCTION OF THE COMMUTATOR. — § 12. If we follow
one of the bobbins of the armature during its revolution be-
fore the poles of the magnet, we shall find that it change?, its
magnetic condition, and consequently its electrical state, twice
during each revolution. Let us take, for instance, the bob-
* A body is said to be insulated when surrounded by substances
which pretent the passage of electricity.
491
bin B' in either figure in its rotation from the north pole ©f
the magnet toward the south pole, as we learnt at § 6, leav-
ing a north pole or approaching a south pole produces the
same effect; and this effect will be that a current will flow
round the bobbin from the right over toward the left. Hence,
if the wire (which is coiled round the bobbin in the same di-
rection) have its corresponding extremity joined to any cir-
cuit, this extremity will be found to be negative. In practice
this extremity is actually connected with the cheek ff of the
commutator. This cheek c1 during the whole of the semi-
revolution of the bobbin B' from north to south, is being
pressed against by the spring d1, which, with its wire e'9 is
consequently kept continuously in a negative state until the
bobbin B' has arrived quite opposite the south pole of the
magnet. At this instant the spring d' touches neither of the
brass half-cylinders, but presses against the ivory, boxwood,
or other insulator, which separates the two half-cylinders of
the commutator c and c' . Hence, no current flows; but di-
rectly Cleaves the middle of the south pole and begins to
complete the under half of the revolution, its cheek comes
into contact with the spring on the opposite side, d. f|But
now we find that the bobbin B' is leaving a south pole to ap-
proach a north pole; therefore, according to § 6, the current
is flowing in the opposite direction round the bobbin. There-
fore the spring d collects from the cheek c' positive electricity.
What has been said of bobbin B7 is, of course, equally true of
bobbin B at similar points of its revolution; hence we see that,
although each bobbin becomes alternately north and south as
it approaches the south or north pole of the permanent magnet,
and sends therefore a current alternately in contrary direc-
tions, yet, since (owing to the insulated half -cylinders) we
are able to cause one spring to pick up the current from the
bobbins whilst the free extremity of their encircling wire is
sending a positive current only (the other spring picking up
the current only whilst the free extremity of the coiled wire
is negative), it follows that the springs d and d' are main-
tained in oppositely electrified conditions. It must be borne
in mind that the wire is coiled continuously round both bob-
bins; hence, that as the bobbins are always exposed at the
same time to opposite magnetic influences, so the conditions
of the two extremities of the coiled wires are electrically
opposite — viz., while one is positive the other is negative^
and vice versd; but that as the bobbin, whichever it be,
492
which travels from north over to south has the free extremity
of its wire always negative and in connection with the spring
d'y while the bobbin (each in turn) which passes under
from south to north has its extremity always positive and in
connection with the spring d! it follows that, providing
always the motion be that indicated by the arrow in Fig. 10,
the spring d1 will always be kept in a negative condition,
while the spring d will simultaneously be positive.
Since the comprehension of the function of the commuta-
tor is of the highest importance in the manufacture of the
dynamo, we recommend the amateur to digest carefully the
contents of this last section.
§13. The next great step in the development of the
dynamo was the application of the current generated by the
armature to the heightening of the magnetism of the magnets
which set up that current in the armature. We have seen
(§ 7) that a current sent round a mass of soft iron converts
that iron into a magnet; and we find that the intensity of
magnetization is, up to the point of saturation, proportionate
to the quantity of electricity flowing round the iron. We
also know that magnets produced by such means (that is, the
passage of currents around soft iron cores) are much more
powerful than permanent steel magnets of equal size and
weight^ Hence, apart from the question of less expense and
greatei constancy (for steel magnets gradually lose their
power by the continuous motion of the armatures before
their poles), there is actually a great gain in efficiency in em-
ploying electro-magnets instead of permanent magnets
wherewith to induce the current, in Hjorth's machine
(which was perfected so far back as October, 1854)
two compound cast-iron magnets A A (Fig. II), which
may or may not be surrounded by a coil of wire, are
bolted to the frame of the machine. These magnets
are shaped like the letter C; and in the gap between
the poles rotates a wheel, B B, on the circumference of
which are fastened several armatures consisting of soft iron
cores wound with insulated copper wire, the ends of which
are brought out to a peculiarly constructed commutator,
which rectifies the dissimilar currents produced. The wheel
(and consequently the armatures) is caused to rotate by
means of the rigger C and driving-axle. Around these
movable armatures, and also bolted to the frame, are several
soft iron cores wound with insulated copper wire, D D D D.
493
The currents produced in the first instance by the passage of
)he armatures before the poles of che magnets, A, after being
tendered uni-direction by means of a commutator, are led on
trough wires to the coils which surround the soft iron
lores, D D D D. These become, therefore, powerful
electro-magnets, and induce in their turn more powerful cur-
rents in the armatures. The larger currents thus produced,
again reacting in their passage on the electro-magnets, super-
*nduce a higher state of magnetism in them, and this again
exalts the electricity generated in the armatures, and so on
until the limit of saturation is reached. The current, after
traversing the coils, is led to terminals to which connection
can be made for exterior work.
It is remarkable that, although this discovery was so
important, and the description and designs were so clear in
the specification, so little attention should have been attracted
to it. Soren Hjorth was, indeed, much before his time,
many of the machines now doing excellent work being
simply trifling modifications of his " magneto-electric bat-
tery."
§ 14.' The intensity of electric and magnetic effects does
not increase in the simple proportion of the nearness of the
bodies acted on, but in a much greater ratio, which, in the
case of electrified bodies and permanent magnets, is directly
as the square of the nearness, or (what amounts to the same
thing) '^inversely as the square of the distance. For instance,
we find that a magnet which exerts a " pull " of i Ib. on a
given piece of iron at 6 inches, if placed at 3 inches, or twice
the nearness, "pulls with a force of 2 X 2 = 4lb.; and if placed
four times as near, namely i^ inches, pulls with a force of
4 X 4 = 16 Ib.
It would appear that in the case
of electro magnets the ratio between
the distance and the effect increases
even more rapidly, being, according
to the best authorities, equal to in-
versely the cube of th<> distance nearly.
Hence it struck Dr. Werner Siemens,
of Berlin, that if the armature could
be constructed of such a form as to
allow of its remaining always very
close to the poles of the magndt
during its rotation, greatly exalted electrical effects would
494
result; and in 1856 he patented in this country the specis
form of armature represented at Fig. 1 1 a, so well known as
the "Siemens" or "H -girder" armature. On reference
to the armatures depicted at Figs. 9 and 10, it will be seen
that during a considerable portion of their rotation they are
at some distance from the legs of the magnets, and even
when near them are not at the points of greatest action.
On the contrary, the Siemens armature is placed as
nearly as possible at the most active portion of the
magnet's poles — viz., their extremities, and at every por-
tion of its rotation some portion of the armature is ex-
posed to the action of the said poles. The Siemens arma-
ture, as shown at Fig. u a, consists of a cylinder of soft iron
between three and four times as long as its diameter, around
the sides and ends of which is cut a deep groove or channel,
rather more than one-third the diameter of the cylinder.
This is shown in section at b. The soft iron cylinder c, has
"brass heads and axes fitted to it as shown at f and g — the
latter carrying a pulley or rigger, by which the armature can
be rotated; while the former is encircled by the commutator
e <?, to which are attached the two ends of the insulated wire,
which is wound in the channel. When in action this arma-
ture is placed between the poles of a
compound horse-shoe magnet, and
supported on trunnions or bearings at
both ends; two springs pressing against
the commutator carry off the electric-
ity generated by the rotation of the
armature, the motion being imparted
by means of a band passing over the
pulley at the farther end of the armature. A general idea oH
this arrangement may be gathered by inspecting Fig. 1 1 H.
CURRENTS GIVEN BY THESE MACHINES NOT CONTINUOUS.
$ 15. Since the direction of the current changes at every
semi-revolution of the armature in such machines as those of
Clarke, Pixii, and Siemens, and at every passage of the com-
pound armature before the poles of the inducing magnets in
Soren Hjorth's machine, we are constrained to use a com-
mutator whenever we desire to produce a current in one di-
rection only. But the commutator, by the very fact of its
being necessarily constructed of two or more portions of a
metallic cylinder, separated by intervals of insulating ma-
dai
Ifi
495
terial, interrupts the passage of the electricity every time that
the springs press against the insulating spaces. Hence the
electricity furnished by these machines partakes more of the
nature of rapidly succeeding waves, than of a steady continu-
ous current, like that furnished by the battery. Still, when
the armature is rotated at a high speed (and the Siemens re-
quires to be driven at about 3,000 revolutions per minute, to
give the best effects), these waves succeed each other with
such rapidity as to simulate a steady current, no break in
continuity being perceptible to ordinary tests.
RAPID MAGNETIZATION AND DEMAGNETIZATION PRODUCES
HEAT,
$ 16. It is found that the sudden change from north magnet-
ism to south magnetism, which takes place in each half of the
above described armatures, as they pass over from before a
south pole to before a north pole of the Inducing magnets, is
accompanied by a very considerable rise in temperature; and
that this rise increases with the rapidity of change of magnetism,
which in its turn depends on the rapidity of rotation.^ So
marked is this rise of temperature, that a dynamo fitted with
a Siemens armature of the pattern figured at § 14, and started
at an initial temperature of 10° C., rises in about twenty min-
utes to nearly 50° C., when driven at 3,000 revolutions per
minute. . This rise in temperature is detrimental to the effi-
ciency of the machine: — ist. Because the wires of the arma-
ture, becoming heated, conduct less freely; hence loss of
current. 2d. Because the armature itself is not capable of
such intense magnetisation when hot as when cold (a red-hot
mass of iron is hardly affected by the magnet); hence another
loss of current. 3d. Because the insulating covering of the
wire is impaired, if not actually ruined, if the temperature
exceeds a very moderate limit.
For these reasons it is important to keep the temperature
of the armature as low as possible. The first successful step
in this direction was taken by Dr. Pacinotti, of Florence, in
1860, who constructed an armature of soft iron, in the shape
of a ring around which were coiled, in successive sections,
helices of insulated copper wire, the ends of which were
joined up to a divided ring commutator The ring armature
of soft iron, with its covering of wire, was supported on a
central axle, and rotated before the poles of a magnet, either
permanent or electro, At no part of the revolution is such
496
a ring taken as a whole farther from, or nearer to, the poles
of the magnet; and although its magnetism is constantly
changing, yet^the change is not abrupt, but gradual and con-
tinuous; as will be explained in the following paragraph.
PACINOTTI'S RING ARMATURE.
§ 17. The description and illustration of this machine is t_
be found in the Nuovo Cimento for the year 1864, under the
heading of " Una Descrizione d'una Piccola Macchina Elettro-
Magnetica." The machine itself, as described, can be used
either as a motor, or as a generator of electricity; and its
adaptability to either purpose was specially dwelt upon by
Dr. A. Pacinotti, in his communication; but it is only under
the aspect of a generator that we shall stop to consider it
here.
Two electro-magnets, S, N, Fig. 12 (which may, or may
not, be united together below),
are fastened to a baseboard, and
so arranged that the upper ex-
Uemity of one is a north pole,
while the other is a south pole.
These poles are furnished with
semi-circular prolongations B B,
B' B', between which is poised,
on the axis C D, a soft iron ring
A A. j?This ring is attached to
the axis by means of radial arms.
Coils of insulated wire are
wrapped round the ring at short
intervals about its periphery, the
IT* 9/2.
end of each coil being brought down the axis at D and at-
tached to one of the small copper strips at E (of which there
are as many as there are coils around the ring), the wire
beginning the next coil being also metallically connected to
this same strip. The wire terminating the next coil is
fastened to the next strip, from whence starts a fresh coil,
and so on, until all the strips, which form the compound
commutator E are connected to the coils in such a manner
'that the end of one coil, by its attachment to its strip, forms
.the commencement of the next. Consequently, the wire
forming the coils, although capable of communicating electri-
cally with the springs F F at opposite points of the diameter
of the cojrw^itator, is really continuous. The ring A A is
497
caused to rotate by means of the rigger G and the driving
belt H.
It will be evident on reflection that the half of ring oppo-
site the pole marked N will acquire by induction south
magnetism, while the half facing the pole S will for a similar
reason become north. Hence the ring, whether in motion
or at rest, will, provided the electro-magnets be active, become
a circular magnet, with the south pole facing the north pole
or the electro-magnet, and its north pole facing the south
pole of the electro. When the ring is rotated, though if
viewed as a whole, this magnetic condition remains unaltered,
yet, of course, any given portion of ,the ring will gradually
change as it passes over from one " horn " or prolongation of
the magnets to the other). Still, the change which takes
place is not abrupt, but gradual, and partakes more of the
nature of a wave than of shock. So also, since the springs of
the commutator press on several strips at the same time, at no
time is contact ever entirely broken between the commutator
and the springs; therefore the current which is produced as a
continuous wave, always in one direction, is collected in a sim-
ilar continuous manner by the springs F F, and may be em-
ployed where required by coupling up the wires I I.
This machine, discovered more than twenty years ago, em-
bodies all the essential characteristics of the best modern
machines, and the much vaunted machines of Gramme, Brush,
Siemens- Alteneck, Maxim, Edison, etc., are, at best, but
trifling modifications of the Pacinotti ring machine — modifica-
tions which have not always been improvements. Having
now brought our brief sketch of the essentials of a dynamo
to a close, we shall proceed in our next section to construct-
ive details.
THE PATTERNS.
§ 18. In the dynamo we are about to construct, three sepa-
rate pieces for patterns are absolutely necessary — viz., one for
the armature, one for the legs of the field magnets, and one
for the standard which supports the fly-wheel. There is no
necessity for the amateur to put himself to the trouble of cut-
ting out a pattern for the flywheel, since such wheels with
handles already fixed can be had for a dollar or so. In con-
structing the wooden patterns, from which the iron castings
are afterward to be procured, the amateur should remember
to choose dry, well seasoned wood, free from knots. Red
pine, for such small work as is required, will be found as
498
good as «4ny. Any joints that are absolutely necessary (and
joints should be avoided as much as possible) should be at-
tached together with dowels and glue. It must be borne in
mind tha the molder places the patterns in green (moist) sand,
and that xhis moisture causes ordinary glued joints to come un-
done or e?\ /and. Any roughnesses left on the pattern also swell
up, catch t\e sand, and thus destroy the sharpness and beauty
of the mo\ \ and therefore of the resulting casting. It is
therefore advisable, after having got the wooden pattern
to the hignest possible degree of smoothness and true-
ness by means of emery-paper, etc., to give it a coating
of melted parafifme wax, and polish the surfaces carefully
with a roll of flannel. This renders the surfaces not only
extremely smooth b*t impervious to moisture, so that the pat-
tern does not warp or swell when placed in the sand. In
order that the pattern should come clean out of the sand and
not break away any portion of the mold, care must be
taken that the edges be slightly rounded, so as to give what
is technically called clearance. The possessor of a lathe can
turn up many portions of the fittings with much greater accur-
acy and rapidity than one provided with only ordinary tools ;
but in the ensuing directions the amateur is supposed to pos-
sess tools of the simplest kind only. ^
$ 19. The pattern for the armature first demands our at-
tention. When completed, it presents the appearance shown
at Fig. 13, a being the elevation and b the section, on a scale
of about half the real size, and consists of a wooden cylinder
i^ inches in diameter by 3^ inches in length, with a deep
channel round the ends and sides. To construct this pattern,
procure a piece of pine 8 inches long by \l/2 inches wide and
^ of an inch thick. Lay this on a table on its widest side,
and draw a line along its whole length, that shall divide it
into two halves of ^ of an inch each. Now, draw a line on
each side of this central line, rather better than y& of an inch
from it. Holding a metal rule against one of these side lines,
with a sharp penknife, cut into the wood along the line to a
depth of about Y% of an inch — rather less than more. Now,
perform the same operation on the other side line to the same
depth. With a sharp yz inch chisel, shave away the wood
on the outside of the cut lines to the depth of ^ of an inch
on the outsides, but rising up very slightly toward the center,
as shown at Fig. 13, c. This precaution will ensure the
pattern lifting out clear from the mold.
500
Now, take a piece of stout cardboard, and with a pair of
compasses strike out a circle \l/2 inches in diameter. Cut the
circle out of the cardboard so as to leave a clean circular
aperture of the diameter specified. Tins is to serve as the
templet, or gauge, of the size and general truth of our arma-
ture. Strike out, also, in a similar manner a circle in
a piece of stoutish zinc, or tinned iron, also \y2 inches
in diameter, and cut this into halves (one of which is shown
at d\. These will serve to shave away the last ^ irreg-
ularities from the wood, when it has been roughly trimmed
up to the shape shown at e, by means of a small plane, or
penknife. The piece may now be cut into two halves across
its length, doweled and fastened together with glue, and cut
down to the exact length required — namely, 3^ inches.
All roughnesses should now be carefully sand-papered, and
care should be taken that the finished pattern should pass
exactly through the cardboard pattern, being appreciably
neither thicker nor thinner at any part. When this has been
effected satisfactorily, a small quantity of paraffine wax (a
piece of paraffine candle will do) should be melted in an
iron spoon, and well rubbed into the pattern at all points
with a roll of flannel until it is thoroughly impregnated with
the wax; rubbing the pattern until it acquires a polish com-
pletes the operation, and renders it ready for the founder.
The thin central portion, which joins the semi-circular por-
tions, should be about 2^ inches in length, having rather *
more than yz an inch cut away at each end, so that the chan-
nel is continuous round the armature, being ^ of an inch
wide and about ^ an inch deep all round.
§ 20. The pattern for the legs of the electro-magnet (field
magnet s> exciting magnets} will
next require our care. Since
the two legs are exact counter-
parts, the one of the other, so
we need only make one pattern,
from which, however, two cast-
ings must be obtained. Fig. 14
illustrates the form and dimen-
sions of this pattern on a scale
of about one-quarter the real
size. The dimensions are
marked in inches. A represents
the outside view, i.e., as seen
from the side which is farthest
from the armature; B gives the
view from the inside (close to
which the armature rotates).
To make this pattern, procure a piece
of pine 6 inches in length, 4 inches in
width, and j£ an inch thick, planed smooth,
and free from knots and roughness. Glue
the dowel along the bottom edge a strip
\Y% inch wide, 4 inches long, and J^ of
an inch thick, as shown at Fig. 15, a.
Now, with a sharp plane, remove half"
the inner edge, as shown at Fig. 15, 6,
so that it makes an angle with the edge
of the 6-inch piece. With a fine saw
cut a recess on each side of the jointed
piece i% inches long by 4 inches deep,
502
as shown at <r, and glue and dowel in each recess the two
flanges, made of j^-inch stuff, of the shape and dimen-
sions given at d. To insure the slot e being exactly at the
same point in each flange, the two flanges, after being roughly
shaped with a fretsaw, or other wise, should be clamped
together, and the finishing touches given with a rat-tail file,
for the slot ey and with sandpaper along the rounded edges.
Care must be taken that these flanges should be a. trifle thin-
»ner near the edge marked 1% than on the opposite edge, to
insure the pattern coming out clean from the mold. For
this reason the slot e must not be narrower at the outside
than at the inside, but rather the contrary. The slot e must
be y of an inch wide, and must reach in depth to the 6-inch
piece, to which the flanges are attached. At this point our
pattern will present somewhat the appearance shown aty. A
piece of wood 4 inches long by ij£ inches wide, and # of
an inch thick, perfectly smooth, square, and free from knots,
must now be chosen, and the two sides planed away, on the
upper side to such an extent as to make an angle of 60° with
the base. (See Fig. 17, a.) With some good, thin, hot glue
this piece is to be glued along the bottom edge of the 6-inch
piece, on the side opposite the flanges, and in such a manner
that the slope of the base is continued by the slope of the
piece, as shown at P'ig. 17, b. When the glue is quite dry,
by means of an inch gouge, cautiously hollow out along the
entire length of this piece, in a simicircular form, nearly to
5°3
the depth of the original 6-inch piece, so as to fit accurately
the pattern of the armature which has already been made.
(§ 19-) When this is as true and smooth as it can be made
with the gouge, fold a piece \?f fine glasspaper over the pat-
tern of the armature, rough side outward, lay the armature
in the channel, and work it backward and forward until per-
fect smoothness and a perfect fit are insured. The pattern
should now present the appearance given at Fig. 17, c.
When this end has been attained, four small dowels should
be inserted into the thicker portions of this semicircular piece,
to hold it firmly down to the 6-inch piece. We now need
only make the top flange, by which the bracket or stand-
ard that bears the wheel is clamped to the legs of the dyna-
mo. This is made most easily in two pieces, one being
squared up to 4 inches long, ^ of an inch thick by $ of an
inch wide. The other piece is to be ^ of an inch thick,
and must be cut into a perfect semicircle, with a radius of
I j£ inches. By means of glue and a couple of dowels, this
is neatly attached to one side of the other square piece, as
504
illustrated at Fig. 17 d, and then the whole is carefully and
squarely glued and doweled, in like manner, to the top of the
6-inch piece, so that it now presents the appearance shown at
A and B, Fig. 14. The holes shown in the bottom and top
flanges may be bored, and core prints inserted, if the founder
will take the trouble to put them in his mold; but, as a rule,
founders do not care to cast small castings with holes in
them, as they seldom come true, so that it will be, perhaps,
as well to have them bored afterward, which can be done at
a small cost. This pattern must now be carefully smoothed,
the sharp edges rounded, to insure parting from the mold,
and finally parafined and polished, as recommended for the
armature (^ 19), when it will be ready for the molder.
§21. The next pattern to be made is that of the
standard, which supports the driving-wheel. This should
be made out of ^-inch stuff, a piece of which 5^ inches
long by 2)4 inches wide must be cut to the shape shown
at A, Fig. 1 6* (one-quarter the real size). In order not to
split the top while boring the hole, it is as well to bore the
hole (which should be yz an inch in diameter) before shaping
the piece. •# For the same reason, the piece marked C, which
should be ^ an inch thick and i inch in diameter when fin-
ished, should be glued to the center of the top end of the piece
A, and the whole bored (by means of a brace and sharp l/2 -inch
505
center-bit) oefore trimming up to shape. From the same
#-inch stuff, another piece, figured at B, is cut out, being
y2 an inch wide at the top, sloping gradually, and becoming
wider to about half its length (d) when it should sharply
curve to a width of 4 inches. The length of this piece should
be 5 inches, and it is to be glued and doweled to the center
of the piece A, close against the boss C, as shown at B. A
small piece e must now be glued and doweled to the edge of
the curved flange, so as to make it flush with the front A.
When this has been smoothed and polished with paraffine, the
patterns are ready for the foundry. The three holes shown
at d may be bored in the castings.
THE CASTINGS.
§ 22. The patterns may now be sent to the foundry, with
the following instructions: First, the armature should be
carefully annealed, so as to constitute a malleable iron casting;
second, two legs should be cast from the pattern shown at
Fig. 14, and these also must be carefully annealed, and be
made as soft as possible; third, the standard (Fig. 17, B)
will be better if left pretty hard, as in this way it will retain
sufficient magnetism to start the machine without adventitic as
aid. Particular stress must be laid on the importance of the
iron in the arflflfture and legs being very soft, since much of
the efficiency of the dynamo will depend on this point. (See
§9.) When the castings return from the foundry, their
degree of hardness may be tested by trying with a rather
coarse file. If the file bites easily, the iron is fairly soft; if
it slips over without filing, it is altogether too hard. (This
does not apply to the standard, which may be left quite hard
without any detriment to the machine). The armature must
now be cleaned and trued up. If the student be the happy
possessor of a lathe, this will not prove a difficult job; if other-
wise, he may, by careful filing, remove any irregularities, and
square up the ends. These must be made quite true; other-
wise it will be impossible to center the armature so as to
rotate it between the poles of the magnet. The thin central
portion shown at a, Fig. 13, and there marked 2^, must
have its edges rounded, so as not to cut the wire, which will
have to be wound round it. No trouble should be spared to
get the armature as truly cylindrical as possible; as care ex-
pended at this portion of the process will render the remainder
of the work very much easier, and more satisfactory. The
506
armature having been thus rendered true, the legs will demand
our attention. Having gone over the surface with a bastard
file to remove any irregularities, the curved channels, shown
at A and B, Fig. 14, must be carefully cleaned out. Perhaps
the quickest way to do this, and to clean the armature at the
same time, is to lay the two pieces, channels uppermost, on a
table, putting a little fine sand and water in the channels, and
then to work the armature up and down the channels, first in
one and then in the other, alternating also the sides of the
armature, until the channels, as well as the external surfaces
of the armature, are rendered quite smooth and bright. The
sharp corners' of the legs of the magnets around which the
wire has to be coiled must also be rounded, and the top semi-
circular flanges, between which the standard has to be clamped,
must be filed quite flat on their inner surfaces, and made per-
fectly parallel with the portions marked 3^ B, Fig. 14. The
standard must also be cleaned in like manner, particular care
being taken that the two sides of the piece marked B, Fig.
16, be perfectly parallel. The edges of the front piece e must
be made perfectly square and true, so as to fit exactly on to
the top of the two legs of the magnets, Fig. 14.
§ 23. Before winding the armature and field-magnets with
the wire in which the electricity is at once generated and con-
ducted, it is necessary to fit together accurately the different
portions, and mark tJiem, so as to be able to put them together
again in precisely the same position after winding; since no
filing or fitting can be attempted on the castings after the
wire has been wound without almost certain destruction of the
insulation, and certain ruin to the neat appearance of the
evenly-laid wire.
The part that calls for the greatest care and attention is the
armature, which, as it must rotate in very close proximity to the
poles of the field-magnets at a rate varying from 1,000 to 3,000
revolutions per minute, requires to be centered most accurately
on its bearings or trunnions. This to the possessor of a lathe
presents but little difficulty; for the benefit of those who de-
pend OR ordinary tools only, the following method, by which
the armature can be mounted on its bearings in a fairly accu-
rate manner, is described. With a pair of calipers, the diam-
eters of the two opposite extremities of the armature are taken.
(If the armature casting were finished up quite exactly,
these two measurements would be exactly alike, viz., a trifle
under \V2 inches each. But unless turned on the lathe, it is
507
very rare to get such precision.) Two circles, of exactly the
same diameters as the two extremities of the armature, are
now to be struck out of a piece of hard sheet brass, % of an
inch thick, care being taken to mark the center and the cir-
cumference in an exact and bold manner with the compasses.
These circles will have to be cut out of the brass with a saw
or file, so as to get two discs, filing each one to its respective
armature extremity; but before cutting out the circles thus
marked, three holes should be drilled in each, viz., one in
the exact center -J- of an inch in diameter, which is to take
the driving shaft or trunnion, and one on each side of this
center, y$ of an inch in diameter, to admit the screws which
serve to attach these heads or discs to the iron portion of the
armature. Besides these three holes, which are common to
both "heads," another pair, also % of an inch in diameter,
must be drilled in one of the heads, to allow the ends of the
wire which is to be coiled around the armature to emerge
from them, and pass through to the commutator. All these
holes are shown full size, and in
their correct position at Fig. 18,
where a is the central aperture, to
take the shaft; If b the two holes
to admit the screws, whereby the
heads are attached to the arma-
ture; and c c holes drilled in one
head only, to admit of the passage
of wires to the commutator.
These holes being bored, and the
discs accurately cut out, two pieces
of hard-drawn iron wire (not galvanized) ^ of an inch diameter
and 2 inches long, are carefully straightened, and by means of
a screw-plate, a thread is put on one end of each. With the
corresponding tap, a female screw is cut in the central hole
of each brass disc. "The two iron rods are then screwed in,
particular care being taken that they enter perpendicularly
and centrally. They must be screwed in until they just pro-
trude through to the other side; then the long end being
allowed to slip between the jaws of a vise, while the disc
rests flat upon the surface of the jaws, a few steady blows
with a flat-pened hammer will spread the bead of the screw
end of the iron rod, so as to rivet it firmly to the disc, and
thus prevent it working out. To render assurance doubly
sure, a drop or two of soft solder may be run round the flat
508
side of the end of the rod and disc. Now we come to a part
of the work that very few amateurs can do at home — viz.,
drilling the holes in the faces of the armature. Any black-
smith will, however, do this for a few cents. Four holes are
required, two at each end of the armature (one end is shown
real size at d d), and these holes must be tapped with a
female screw, so as to take the screws which serve to unite
the whole together. It will be well to let the blacksmith
drill and tap these holes to any sized screw that he has near-
est approaching % of an inch in diameter. Now will be
also the time to get the blacksmith to drill the three holes,
right through the top end of the legs and standard, which
serve to allow these portions to be clamped together by
means of bolts and nuts. These
holes should be about ^ °f an
inch in diameter. Further de-
tails as to position and size will
be given a little farther on. If
our work has been properly per-
formed, the heads may now be
screwed down to the armature
with flat-headed screws, which
should project about -^ of an
inch above the level of the disc.
Fig. 19 gives a representation of
the finished armature about half
the real size.
§ 24. Our next proceeding is
to clamp together the stand-
ard, or bracket, which serves to support the wheel to
the two legs of the field- magnets. At the concluding
portion of $ 23, we adverted to the advisibility of getting
the holes bored right through the top end of the legs
and standard, at the same time that the holes were
being drilled in the armature. The position of these holes
f is indicated at Fig. 20; they should
*'*' be about % of an inch in diameter, and
, the two lower ones should be at least •%
of an inch from the bend of the flange,
, so as to allow the nuts to be easily turned
and tightened up. These two bottom
holes should be about two inches apart,
while the upper one should sUnd equi-
distant from the others, but at about ^
5°9
an inch from the top of the flange. The amateur will find at
any hardware store, very neat skate-screws with nuts to fit,
of the form illustrated at Fig. 21. These screws have usually
rounded heads, without the slot for the screw-driver to enter;
but these can be easily cut with a metal saw. Of course,
any small bolts and nuts hav-
ing a section of about # of an
inch will do, but the ones men-
tioned are very neat in appear-
ance. The holes being drilled
and the bolts and nuts chosen,
the bracket and limbs of the
field-magnet may be tempo-
rarily clamped together, in
order to see what opening is
left between the legs for the
armature to turn in, at a, Fig.
22. In all probability some
filing of the faces of the flanges
and of the bracket will be nec-
essary to insure a proper fit.
A well-fittedarmature, if placed
in the center of the channels at
a, should leave a space of a trifle more than ^^Df
an inch to turn in; that is to say, there should be ratner
more than -}$ of an inch clear space all round between the
armature and the field-magnets. Perhaps the quickest
way to insure this distance being obtained is to roll
tightly a single fold of stout brown paper round the
armature and seal down the edge to prevent it slipping; then
having inserted the armature in the channels, to file away at
the inner faces of the flanges, either toward the lower por-
tions at b b, if the channels are too wide apart, or at the
upper extremities at c <r, if too close, until the whole fits
accurately together. It is needless to remark that when the
armature thus wrapped in paper is placed between the field-
magnets, to obtain a correct fit, the solid portions of the
armature should lie against the legs, and not the portion of
the armature which is hollowed out for the reception, of the
wire.^. (See Fig. 22.)
$25. The magnets and brackets being thus properly
clamped together, the hole in the top of the bracket (which
ought to have been left in the casting, but if not may be
5io
bored now) should be cleaned out to ^ an inch in diameter.
When this is done, two pieces of hard rolled brass sheet %
of an inch thick, 6 inches long by I inch wide, must be cut
out and squared up. One of these, which we shall for the
future call the " back bearing," and which must be made to
fit that end %of the dynamo at which the driving wheel is to
be placed, and which we shall henceforward call the " back *
of the dynamo, is to be bent four times at right angles, as
shown at Fig. 23, a, where the dimensions are given. In
Fig. £8.
3fr inches. »
*
<JU
mmmm
&
A
o
order not to crack the brass while bending to shape, it will
be well, after having given the general form by bending
gently and gradually over the jaws of a vice, to heat the
bends over the flame of a spirit-lamp until nearly red hot,
and then to hammer up more exactly to shape, repeating the
heating after each hammering until the desired sharpness of
outline ha«; been obtained.
When this object has been attained, another almost similar
bearing is formed out of the remaining piece of sheet brass,
the principal difference being that, as this is to be the front
bearing, between which the commutator will have to turn,
a much greater depth must be given to the central bent
portion, as may be seen at Fig. 23, b, the dimensions being
given in inches as before. When the brass has been bent
to these forms, the bearings thus produced should be laid
each against its own respective end of the dynamo, in such
a position that the center of the bend comes in the center
of the channel, the two flat extensions lying close to, and
flat against, the slotted lugs shown at Fig. 22, d d. The
bearings should now be cut in a sloping fashion to follow the
outline of the lugs, as shown at Fig. 23, c ; but the outline
of the slotted portion should not be followed, as a J^-inch
hole must be drilled in the brass at this point to take a
5-inch bolt and nut. The exact position of these holes may
be obtained by holding each bearing in succession against its
own proper extremity, and scratching with a steel point on
to the brass the position in which the slots in the lugs fall ;
hen, with a Morse twist drill, a ^-inch hole can be drilled
at each extremity nearest to the center of the bearing, as
shown at Fig. 23, d.
Having got so far, let us clamp the back bearing in its
place by means of two bolts about 5 inches long, passing
through the holes in the bearings and through the slots in
the lugs, held in their places by two nuts screwed down on
to the front lugs of the dynamo. Taking the armature in
one hand, we roll, as before, one fold of paper round it, and
put a dot of Brunswick black on the extremity of the trun*
nion rod at the back end of the armature (the end where the
holes are bored for the wire to come out is the front, the
other is the back), and then insert it into the channel
between the legs of the field-magnets, until the trunnion rod
on shaft touches the brass forming the back bearing. In so
doing it will leave a mark of Brunswick black, which will be
the point at which a #-inch hole must be bored. This
must be done most carefully, so as to preserve centricity ;
and when done must be rimed out and bushed with a piece
of brass tubing of about -^ external diameter, the internal
diameter of which must exactly correspond with the external
diameter of the driving-shaft or trunnion of the armature ; in
fact, this latter must fit exactly into the tube, without any
shake. This piece of tubing should be about i# inches in
length, and should be soldered into the central hole in the
back bearing, and should extend inward to such a degree
that when the back bearing is clamped in its place, with the
armature in its position, with the back trunnion in the tube,
and the back head flush with the back of the magnets, it
should just rest against the back head of the armature.
In a precisely similar manner the center of the front
bearing is found ; that is to say, the back bearing being
removed, the front bearing is clamped to the front of the
dynamo, the armature, rolled in one fold of paper, is inserted
from the back end of the dynamo, front end forward, and
care taken to moisten the front end of the driving- shaft with
Brunswick black or other color, so as to get a mark where
it touches. The hole being drilled and rimed out, as in the
previous case, is to be likewise bushed with the same kind of
brass tubing ; but in the front bearing, the tube should be
only flush with the inside of the bearing, and sJiould not
extend in toward the armature.
§ 26. The Commutator 'next claims our care. This essen-
tial piece of apparatus serves, as the student may remember
(^ 12), to rectify, or send in one direction, the vibrations or
currents which are produced in opposite directions, as each
pole of the armature passes alternately before the north and
south pole of the field-magnets. In screwing the brass heads
down to the armature, the student was advised (§ 23, Fig. 19)
to employ flat-headed screws, projecting about § of an inch
above the level of the discs. The use of the projecting
heads is to prevent the commutator slipping round the axis
or trunnion of the armature when the latter revolves. The
body of the commutator may be turned up out of a piece of
sound boxwood, which previous to turning up should have
been allowed to soak for a couple of hours in melted parafrine.
It should, when finished, present the appearance shown at
Fig. 24, a. While on the lathe, a hole, perfectly central,
should be drifted right through it, into which the front shaft
or trunnion of the armature fits tightly. The length of this
should be 1 2 of an inch, so that it just clears the front bearing
when in its place. The diameter should be about |-ofan
inch, so that the two flat-headed screws of the front arma-
ture head should be covered by the cylinder on opposite
sides of its circumference to the extent of about }/% of an inch.
Two semicircular nicks must be cut out of the bottom of the
cylinder to allow these screw heads to enter, so that the
cylinder when driven home rests quite against the disc or
head. The front of this cylinder (the part farthest from the
disc) must be rounded slightly, so as not to present too great
a surface for friction against the front bearing. A piece of
brass tube, ^ of an inch shorter than the cylinder, and of such
internal diameter as to fit tightly on it, is now cleaned up and
cut into two exactly equal halves longitudinally. The cuts
must not be quite parallel to the axis of the cylinder, but
must make a small angle with it, in order that the " brush "
or spring which takes the current off the commutator should
at no time abruptly leave one half tube before it rests on the
other; otherwise the commutator sparks badly while at wrork,
and the sparks injure both commutator and brushes, besides
entailing loss of current. The amount of angular deviation
from the line of axis should not, in this machine, exceed two
or three degrees of arc, and care must be taken they are
equi -distant, and both inclined in the same direction. To
insure this, stand the tube (already cut to length and cleaned)
on one end. Take the exact diameter with a pair of com-
passes, and strike out on a piece of card a circle of exactly
similar diameter. Rule two fine lines across this circle, both
cutting the center, but exactly ^ of an inch apart at the cir-
cumference, like a letter X. Lay this card on the top of a
tube, and with a steel point or file make a mark on the rim
of the tube at each of the points where the lines touch the
circumference of the circle. Now lay the tube on its side,
and draw four lines straight along the length of the tube,
starting from the points just marked. Fach opposite pair of
lines will be exactly £ of an inch apart, and quite parallel.
Having done this, bring one pair of lines uppermost, and
draw a diagonal line from the top of the right hand to the
bottom of the left-hand line. Now turn the tube half a rev-
olution, so as to bring the lower pair of lines uppermost, and
draw a similar diagonal line, in the same direction- viz. ,
from the top of the right hand line to the bottom of the left-
hand line. Now, with a fine fretsaw cut the tube into two
halves in the direction of the two diagonal lines just de-
scribed. The tube, with the diagonal lines marked ready for
cutting, is shown, as if transparent, at Fig. 24, b. It will be
noticed that though, when seen through, these lines cross
each other, yet when either portion of the marked tube is
uppermost the line of division is from right downward to
left* The split tube is now to be fastened to the boxwood
cylinder in such a position
that the middles of the lines
of division shall be exactly
in a line with the middle of
the channel of the armature.
(See Fig. 25.) These two
half-tubes may be attached
to the boxwood cylinder or
core by means of two short
flat -headed screws, care be-
ing taken that these screws
•J£^J^ do not reach to make con-
tact with the trunnion or
touch the "head' of the
armature. The split ring,
5*5
when fastened in its place, should reach to within about ^
of an inch of each end of the boxwood core; and if screws
are used to fasten it down these should be placed at the end
nearer the armature. But another \ery neat and effective
way of attaching the split tube or ring to the core is by means
of two narrow ivory or bone rings, forced over the split tube,
one at each end. Care must be taken, in either case, that
the divisions in the split tube are maintained; for, of course,
if the two halves of the tube were allowed to touch at any
point the current would flow round at that point or " short
circuit," and no current would be perceptible on the outside.
To insure the distance being maintained, it is well to place a
shaving of paraffined wood of the same thickness as the saw-
cuts between the two halves of the split tube on both sides.
§ 27. Those who have not a lathe can make a very fair
substitute for the boxwood cylinder by rolling and gluing a
stout piece of brown paper/ just as if making a rocket-case,
around a piece of the same iron rod that served for the trun-
nions of the armature, until a cylinder % of an inch thick
and §| of an inch long has been produced. ' This should be
rolled very hard while on the iron rod, so as to insure
its being truly cylindrical; the rod on which it was rolled
should then be pulled out, and the tube allowed to dry thor-
oughly. When dry it should be soaked for half an hour in
melted parafnne, then reared on end to drain and cool. It
will be found to work extremely well. Of course the split
ring can be attached to this, either by screws or by two rings,
as in the former case.
§ 28. Two rectangular pieces of boxwood (previously
boiled in paraffine) must now be cut, planed and drilled.
These are the " brush blocks," which serve to support the
metalliq^prings or " brushes " which press against the com-
mutator. Some operators prefer to mount their blocks on
the stand, separate from the dynamo castings; here the pfan
followed is to cause the bolts which clamp the bearings to
the field-magnets to carry the brush blocks. To this end the
two pieces of boxwood should be cut so as to fit exactly the
space left between the shoulders of the front bearings
on the outside^ and bored so as to allow the bolts to come
right through to take the nuts; that is to say, the blocks will
be almost cubical in shape, being i inch long, \\ of an inch
wide, by % of an inch thick. Fig. 26 shows one of these
blocks in its place, clamped to the bearing by the nut and bolt.
5*5
$ 29. In order to communicate the motion from the fly-
wheel to the armature, a small pulley -wheel, either of iron
or brass, is fitted to the back trunnion, just outside the
bearing. Such a pulley- wheel may be bought at any hard-
ware store, and should be about i% inches in diameter, and
rather over % of an inch thick, with the central hole some-
what smaller than the diameter of the rod which serves for
the armature trunnion. This
may be attached to the trunnion
in either of the two following
ways: ist. By " keying, "which
consists in filing the trunnion
along its length in one direction
only, so as to produce a flattened
side; then, having with a rat-
tail file cleaned out the central
hole of the pulley to such an ex-
tent that the said trunnion will
only just enter, to deepen one
side (corresponding to the
flattened side of the trunnion) so
as to admit of a small steel
wedge or " key " being inserted.
(See Fig. 27, a.) 2nd. By filing
the trunnion-rod to a slightly
conical shape, and producing a
similar " coning " in the interior
of the pulley hole, which may
then be driven on. (See Fig.
27, />, where the " coning "of the
trunnior, is exaggerated, to
render this mode of attachment
more plainly visible.) Which-
517
ever mode of attachment is adopted, one precaution must be
taken — viz. , that the distance between the back of the
field-magnets and the pulley should" not be less than i#
inches; otherwise, when the limbs of magnets are wound with
wire, the fly-wheel will run too close to them to be altogether
safe.
§ 30. The fly-wheel which gives motion to the armature
should be a pretty heavy wheel, about 13 inches in diameter,
with a groove in the rim to take the band which drives the
pulley, furnished with a wooden handle for convenience of
rotating. Such wheels may be obtained ready made in cast-
iron, from most hardware or agricultural implement dealers,
as they are sent out with "rotary blowers," "portable
forges," etc. Fig. 28 a gives an idea of the kind of wheel
necessary, on a scale of i^ inches to the foot. The central
hole is turned, and only requires fittting with an
iron pin, on which it turns. Since the aperture
in these wheels is about ^ of an inch in diam-
eter, the pin must be filed down to yz an inch diameter,
where it hns to fit the hole in the flange at the top of the
dynamo.
The farthest end should have a rounded head, to prevent
the wheel from working off, while the portion which passes
into the eye at the top of the flange must have a thread put
on it, so as to take a nut. (See Fig. 28, b.}
§ 31. All the portions of the dynamo being now fitted, they
should be marked so as to insure putting together again in right
order after winding. When this has been done; the limbs of
the field-magnets, at all parts except the channel for the arma-
ture, and the inner face of the semicircular top which rests
against the wheel bracket, should receive a coat of good
Brunswick-black, allowing them to dry between each applica-
tion, in a warm oven. The bracket should likewise receive
a coat or two of the same varnish, except where semicircular
tops clinch it. This portion must be left metallic, so as to
insure magnetic contact; otherwise much magnetic power is
lost. Two strips of silk (color immaterial) 10 inches long by
3^ inches wide, should now be quickly brushed over with
Brunswick-black, and wrapped, while still sticky, one round
the one limb, and the other round the other limb of the field-
magnets, in the space between the armature channel and the
bend at the top. (See Fig. 14, where the portions indicated
are marked respectively 4" and 3%". ) The object of this silk
wrapping is to insulate the wire thoroughly from the iron,
and to prevent any accidental abrasion of the covering wire,
which may take place during careless winding from short cir-
cuiting to the iron below. When the silk has been laid
smoothly and tightly on, the limbs may be returned to the
oven, and allowed to dry at a gentle heat. In precisely the
same manner the intetior faces and their central portion of
the armature (technically known as the " web ") must be var-
nished with Brunswick-black, and wrapped with one layer of
similarly prepared silk. Three pieces will be required to do
this effectually — viz., two pieces 3^ inches long by i^
inches wide, shaped as in Fig. 29, to fit against the
inner faces, and one piece 6 inches long, by ^ of an inch
wide, to wrap round the web. Particular care must be
taken that every portion of the inside of the armature's
channel be entirely covered in silk. When this has been
satisfactorily performed, another coat of Brunswick-black may
be given (avoiding to soil the outside), and the armature
allowed to dry thoroughly in a warm oven.
§ 32. Our dynamo is now ready for wiring. For this pur-
pose we shall require about 7 Ib. of No. 16 single cotton-
covered copper wire for the field-magnets, and about ^ Ib.
No. 20 double silk-covered for the armature. The amateur
should be careful to get new wire, of the highest conductivity,
and very soft; the employment of old, kinky, and hard wire
is fatal, to success.
§ 33. The quantity of wire above mentioned having been
duly selected, it should be tested for continuity. The No.
16 will give evidence to the sight alone, whether there be
any break in it or not. Should there be such, the covering
from the two broken ends should be uncovered for about an
inch on each end, the two extremities filed down to a fine
flat wedge, so as to fit one another, when each one separately
should be warmed for a second over the flame of a spirit-
lamp, dipped into powdered resin, and rubbed, while being
held in the flame of the lamp, with a rod of solder, until
each has taken a good coating of solder. The two ends may
then be applied with their flattened portions together over
the flame of the spirit lamp until the solder coating melts.
Keeping the ends pressed together, the wire is to be removed
from the flame. The solder soon hardens, and the wires will
be found firmly united. It is now only necessary to file
away any roughness, and rewind the cotton covering over the
519
bared portion, adding a little darning-cotton if the covering
be deficient. The finer wire, which is generally bought on
reels, had better be tested with the galvanometer (Fig. 2).
To this end, find the two extremities of the wire, attach one
to one binding-screw of the galvanometer, the other extrem-
ity being in good metallic contact with the pole of any single-
cell battery. Connect the other pole of the battery with the
other binding-screw of the galvanometer. An immediate
and large deflection of the needle will show that the wire is
continuous. If not, the wire must be unwound from the
reel, and carefully wound on to another until the point at
which the break occurs has been discovered. The two broken
ends maybe joined as described above, great care being taken
after joining to recover the point of junction thoroughly, so
as to preclude all danger of leakage, more silk being used to
this end if necessary. It having been ascertained that the
wire is perfect and in good condition, the next step is to soak
it in melted paraffine wax, The good effect of this is twofold:
(a) The insulation is thereby rendered very much better;
(b} a damp atmosphere has then little or no effect on the in-
sulation, since the paraffined cotton and silk covering is no
longer hygroscopic, and may actually be pumped upon with-
out becoming wetted or spoiling the insulation. To paraffine
nicely the wire should be laid in a shallow dish large enough
to contain it easily — a circular tin baking dish will do admir-
ably. It should then be placed in a warm oven, not too hot,
until it is about the heat of the hand — say, 90° Fahr. About
% Ib. of good paraffine wax should now be placed in the
tin, and the oven closed until the paraffine is all melted. The
wire may then be turned over two or three times until it is
seen to be thoroughly soaked with the paraffine. Two or
three metal rods should now be placed across the top of
the dish, on which the wire may be placed to drain for a few
seconds while still in the oven. When it ceases to drip it
may be removed from the oven and allowed to cool. The
superfluous paraffine, while still hot, may be poured into
a cup (which has been just previously breathed into) to
set, when it may be used for other insulations.
1 3 j. Winding the armature next clains our attention.
Having marked the heads, so as to know which belongs to
a given extremityof the armature, we unscrew and remove
them; about 6 inches of the extremity of the No. 20 wire
should be coiled tightly round the end of a pencil, so as to
520
form a tight helix from which the pencil must then be slipped
out. This helix will form one of the spare ends of the wire
which will be attached to the commutator, and should be, for
the time being, tied with a bit of silk to the outside of the
armature, so as to be out of the way while winding. Hold-
ing the armature in the left hand, with the end which corre-
sponds to the commutator facing us, and beginning at the left-
hand cheek, we wind the wire in the channel, continuing to
wind until we reach the right-hand cheek, taking care to lay the
wire on as closely as possible, never allowing it to ride over
its neighbor, nor yet to leave gaps between. When .one
layer has thus been carefully wound on, as shown at Fig. 30,
it should be tested for insulation, since
the amateur is very apt to wind care-
lessly and cut the insulating covering,
either by catching in the sharp corners
of the channel or otherwise. To test
for insulation, tie the end of the wire
(without detaching it from the reel or
hank) against one cheek of the arma-
ture, to prevent its unwinding during
the trial; then connect one pole of a
battery to one binding-screw of a gal-
vanometer, and the helix end of the
wound wire to the other binding-screw.
On touching the iron of the armature at
any point with the other pole of the bat-
tery, no deflection of *he needle should
take place. Should a deflection show itself, evincing a
metallic contact and want of insulation at some point, the
wire must be unwound, the flaw localized and remedied
by a fresh covering of silk, basted with paraffine, and again
wound on and tested until the insulation is satisfactory. A
layer of thin paraffined paper should now be laid over the
first layer of wire, and the winding proceeded with in exactly
similar manner, until the second layer has been laid on,
remembering that the essentials of success are to wind the
wire as closely as possible in each layer without overlapping;
to avoid grazing the covering of the wire, so as to maintain
insulation, and to wind always in one direction — viz., from
us, over to under. There is no necessity (when using silk-
covered wire) to place a stratum of paraffined paper between
«ach layer of wire, as this, by increasing the distance between
521
the layers, somewhat decreases the efficiency of the machine;
this is only advisable when the insulation of the wire has been
found to be imperfect. The winding should be proceeded
with, layer after layer, evenly, tightly and smoothly, until the
wire just fills the channel. Care must be taken that it does '
not exceed this, for if it comes higher than the cheeks it will
surely catch in the limbs of the field-magnets during rotation.
From eight to nine layers of wire may be laid on, according
to the tightness with which it is pulled during winding.
When the due proportion of wire has been laid on, it should
be fastened down by tying, so as not to unwind, with its free
end at the same extremity (the commutator end) as we
started from. The helix may now be straightened out, and
its condition observed, to insure that it is well insulated.
The end at which we finished winding should also be
straightened out and examined for good covering Then
a stick of elastic glue should be heated and rtibbed
over the covered ends right up to the armature, so
as to thicken them to such an extent that they will
only just pass through the holes bored in the head to which
the commutator is attached. (See Fig. 18, c, c,\ The
wire ends should be passed one through each of these holes
(care being taken that the head be put on as it was previous
to removal), pulled pretty tightly, but not so roughly as to
graze or injure the covering, and having been cut so as to just
reach the heads of the screws, which fasten the two halves
of the split tube of the commutator to its cylinder (see Fig.
25), should have their extreme ends unwound and cleaned,
and then be soldered down, one to each half of the split
tube, care being taken that neither the solder nor the wire
passes beyond the line of the screws; so as to leave plenty
of room for the brushes to press against the commutator.
The heads may now be screwed up in their place, and a
coat of good sealing-wax varnish (best made by dissolv-
ing good scarlet sealing-wax in methylated spirit) painted
over the layers of wire, both for the sake of appearance
and to keep the wires from moving out of place during
rotation, though if the wires are tightly wound this would
be hardly needful. This coat of varnish must be allowed
to dry off in a warm atmosphere (not in the oven), and
the armature will be complete.
? 35. Our labors are now drawing to a close. To wind
the field-magnets it will be as well to rig up a little piece of
apparatus, since, although they may be wound without, it
is very difficult to lay the wire as closely, as tightly,
and as neatly as can be done by its aid; and since the effi-
ciency of the machine is greatly exalted by the greater proxim-
ity of the wire to the core, it is a matter of considerable
importance that this should be attended to. The apparatus
necessary consists of a handle fastened to an axle passing
through a standard supported on a base; the axle having a
prolongation to which each limb of the field-magnets can be
screwed down in its turn. On turning the handle, it is evi-
dent that the iron mass of the field-magnet will rotate on its
axis, and if lare be taken that the center of the mass coincides
with the center of motion, the motion imparted to the iron
will be smooth and even, and the wire may be laid on with
great exactitude and closeness. This apparatus is illustrated
at Fig. 31, a, with one of the limbs of
the field-magnets screwed in its place,
ready for winding. It should be made
out of ^-inch stuff, the base being
about 5 inches wide by 6 inches long.
The upright through which the axle
passes should also be about the same
size, and screwed to the edge of the
baseboard, so as to stand at right an-
gles to it. A short piece of broomstick,
about ^ of an inch in diameter, may
be used as the axle, and a hole must be bored in the upright,
at about 4 inches from this base, to admit this axle. To the
external portion of the axle is fastened a handle; while to the
internal portion, which should protude about i)4 inches, is
screwed a piece of J^-inch stuff about i% inches square, half
the axle being cut away to admit of its lying flat. Previous
to screwing down, the handle, as well as
this latter square piece, should be
rubbed over with a little good hot glue
at the places where they touch the axle,
to insure a good sound joint. This
*' winder " being completed, it may be
clamped to a bench or table by means
of a sewing-machine or fretsaw clamp,
the leg of the field-magnet having been
previously screwed to it by means of the
three holes in the flange, in the position
shown in the figure. Though shown in
523
the cut to the left, the handle of the winder should be to the
right of the operator, unless he be left-handed. In commenc-
ing to wind the wire, the operator should stand over his
work, a sheet of paper having been placed on the floor, and
the coil of paraffined wire at his feet, with a two-gallon stone
bottle filled with water, to keep the bottle from upsetting, in
the center of the coil to prevent its tangling or kinking. The
surface of this jar being glazed, the wire slips from it without
injuring the covering. The winding should be commenced at
the extremity farthest from the handle — that is, nearest to
the channel in the field-magnets in which the armature ro-
tates. Six or eight inches of the wire should be coiled round
a pencil, and so as to form a tight helix, which, with a piece
of strong twine, should be tied to the leg of the magnet, as
shown in Fig. 31, b. Holding the loose end of the wire
in the left hand, keeping it pretty tightly pulled, and
straightening it out from its coiled shape as it passes through
the fingers, it is easy in this manner to wind the wire per-
fectly flat and smooth by turning the handle of the winder in
the direction of the motion of the hands of a watch. (In or-
der to prevent any accidental contact though abrasion against
the corners, etc. , it is advisable previously to cover the legs
of the field-magnets, at all events as far as the wire is to ex-
tend— viz., from c to d in the present figure — with a band of
silk dipped in melted paraffine, and applied hot to the iron,
when it will immediately adhere. This band must be care-
fully smoothed down, so as not to cause unevenness in the
winding of the wire.) If the wire be nicely laid on, it will
be found possible to wind forty rows between c and d. Be-
fore arriving at d it will be necessary to place two pieces of
tape about ^ an inch wide and 3 inches long, as shown
at e e in the figure, the free ends of which must be turned
back smoothly and tightly over the layer just put on when d
is reached. Continuing the rotation of the handle in the
same direction, another layer of wire is now laid over
the first; by holding the ends of the tape fast while
beginning to wind this second layer, all tendency of sinking
into the layer beneath, which may be displayed by the
second layer, is overcome. Without this precaution it is
almost impossible to prevent the outer layers of wire sinking
into the interspaces of the layers below. Continuing in this
manner, layer after layer should be laid on until seven layers
have been wound, remembering to use tapes toward the end
524
of each layer, and that each layer will diminish by two rows.
When the seven layers have been laid on, the wire must be
tied down to the magnet to prevent uncoiling, and cut off
from the hank of wire, leaving about 6 inches free for attach-
ment.
In exactly a similar manner as regards attachment, direc-
tion of winding, etc., must the second limb be wound. The
only difference that need be made is that, for convenience of
having both ends of wire at the same end of the dynamo, it
will be well to fasten the beginning of the wire (the helix) to
the inside of the leg instead of to the outside. Fig. 31, f,
will make this clear.
§ 36. Both for the sake of appearance and to further pro-
tect the insulation from damp air, etc. , it is advisable to give
the wires on the limbs of the field-magnets a coat of
good varnish. The best for this purpose is made by mix-
ing about 2 ounces of the best red lead with yz an ounce
of good white hard varnish. The two should be well incor-
porated together by working with the brush intended to be
used for laying on the varnish.
The varnish should be applied in a thin layer with a soft
brush, so as to disturb the paraffine coating as little as possible,
since if the paraffine mixes with the varnish, this latter never
dries, but remains a sticky mess. For this reason the coating
of varnish should be allowed to dry without the application
of heat, which, if the " white hard " be good, it will do in
about eight to twelve hours. A second coat may be given if
desired; but as this generally fills up the interstices between
the layers of wire, it detracts somewhat from the neatness of
the appearance.
$ 37. The varnish being quite dry^ the dynamo may again
be put together, care being taken that the parts are ad-
justed in the position which they occupied after fitting. If
this has been properly done, the armature ought to turn
freely in its bearings quite close to the limbs of the field-mag-
nets, but without catching anywhere.
Supposing this to be all right (and it must be so, or the
dynamo cannot work properly), the dynamo must be screwed
down to a baseboard, wnich should consist of a slab of oak,
walnut, or mahogany, 10 inches long by 8 inches wide, and
at least i inch thick. The two holes in the lower flange in
the limb of the field- magnets, near the channel in which the
armature revclves, are expressly for the purpose of clamping
525
the dynamo to its baseboard. The baseboard should be
chosen of a well-seasoned nature — polished, for appearance
sake; and the dynamo should be screwed to it centrally, with
the narrowest portion of the dynamo parallel with the narrow-
est portion of the baseboard.
ATTACHMENT OF THE WIRES.
§ 38. The dynamo having been wound as described (and
care must be taken to have fulfilled the instructions exactly,
or else the resulting magnet will
have two north poles, ortwoj0///>fc
poles, instead of one north and
one south), we can proceed to
couple up the various parts. To
this end we begin by joining the
wires at the two extremities at
which we left off winding. This
may be effected by removing a
portion of the covering of the
•wires (by scraping with a sharp
knife) for about an inch along the
places where the two wires cross
each other if made to touch. (See
Fig. 320.)
The wire must be made quite
bright and clean by rubbing with a bit of sandpaper at this
point, and then the wires are twisted tightly together by the.
aid of a pair of pincers. A drop of solder, taken ujfon a hot
soldering-iron and run along the twisted portion will insure
the contact remaining good. The excess of wire should now
be cut off from the twisted end with a pair of cutting pliers;
the bared twist bound round with a layer of darning-cotton,
varnished with the red varnish (§ 36), and turned in out of the
way between the limbs of the magnet. (Fig. 32, b.} k
We may nowproceed to magnetize the field- magnets. ' For
this purpose we need only attach the poles of a single-cell bichro-
mate battery, exposing from 8 to 10 square inches of negative
surface, to the wires of the dynamo for a few seconds; but in or*
der to obtain results which may be deducible from reason, and
which can be corrected if mistakes are made, it is desirable to
determine beforehand which shall be the north pole of our
future magnet. It will be remembered (§ 8) that we have it
in our power to produce a north pole, to our left, in a mass-
526
of iron, by passing a current of electricity away from us,
ever it; and if we wish to produce a north pole to the right,
-the current must come toward us, over the mass. ^
Let us decide to make a north pole of the limb on which
we began to wind the wire on the outside. (See Fig. 31, c.)
To do this the current ought evidently to flow from the
limb of the magnet to the observer; in other words, this wire
must be attached to the negative pole of the cell. (The
negative pole of the bichromate cell is the wire proceeding
from the zinc, the one attached to the graphite being posi-
tive.) The positive pole of the cell must be coupled to the
other wire, that is, the one which was started from the
inside in winding. (See Fig. 31, f.)
While the battery is thus coupled up to the dynamo, we
can test if we have produced the effect desired by bring-
ing a suspended magnetized needle near the supposed north
pole of the dynamo. If all has been properly performed, it
will be found to attract the south pole of the poised needle,
And repel its north pole,
A few seconds' connection with the battery will impart
as much magnetism to the field-magnet as it will retain; but
that little will be sufficient for our purpose. Our next step
is to discover in which direction the current flows in our
armature, when we rotate the fly-wheel in the usual way
with the right hand (in the direction of the motion of the
hands of a clock). Before we can do this we must fasten
two "brushes" or collectors on the brush-blocks, in order to
collect the electricity generated by the revolution of the
armature.
THE BRUSHES.
§.39. These consist of two pieces of springy sheet brass,
y., of an inch thick, 3 ^ inches long, and about ft of an inch
wide. They must be bent twice at right angles, so as to fit
tightly on to the brush-blocks (§ 28, Fig. 26), and slightly
curved inward at the longer portions so as to press
with some force against the commutator. (See Fig.
32, c.) To fasten these on to the blocks, a lateral slot is cut
about half-way into each brush, at about y$ of an
inch from the longest portion, of such a width as to
admit the shank of a small screw passing into it. The por-
tion of the brush which rests against the armature should be
sli; into two or three divisions, and curved slightly upward
to avoid scratching the armature.
527
These two brushes, though alike in shape, must be pat in
opposite positions on the dynamo ; that is to say, the one
which goes o.n the block to the right of the observer has the
longer portion above the block, while the one which goes on
the left-hand block has the longer portion below the block.
Thus the commutator is rubbed by these two brushes
at diametrically opposite points. Care must be taken that
the two screws which serve to fasten the brushes to the blocks
do not touch the metal of the bolts which clamp the bear-
ings to the dynamo, for if they did the current woul d short-
circuit, and the machine would not work. It will also be nec-
essary to observe that sufficient curvature be given to the
longer portion of the brushes to clear the bearings alto-
gether, otherwise, of course, the
current would pass into the bear-
ings and be short-circuited. Fig.
33 shows the brushes in their
proper position ; a, a being the
commutator (exaggerated in size
omewhat to show its position),
d, b the brush-blocks, c, c the
brushes, and d, d the screws which, by being tightened or
loosened, can increase or decrease the pressure of the springs on
the commutator, and to which the two wires which form the
electrodes of the commutator are to be attached. These two
wires, which in our machine may be about 3 inches long, with
a loop at each end, as shown at Fig. 34 «, should be of No.
16 cotton-covered copper wire, the covering being removed
from the two loops, which must be made
quite bright. Before putting in the screws ^
d, d, Fig. 33, each one should be passed <j> ^ ^^ ^
into one eye of one of {he said wires, then
screwed partly into the brush-block, when the brush itself
may be pushed into its place over the block, and under the
screw, the slot in the side admitting of this;
lastly, the screw is tightened up until the desired
pressure on the commutator is obtained.
Fig. 34 shows the position of the wire, screw,
and left-hand brush on the left-hand block. The
1 two free ends of the wires just described project
straight forward to the front of the machine;
they may be screwed down on the baseboard,
at the distance of about 3 inches apart, by means
5-3
of a small pair of binding-screws ; the long screws 01 which
are passed through the free eyes.
Y\ e can now test the direction of the current in our arma-
ture. To do this we place the fly-wheel on its bracket, put
a leather band (such as is used for treadle sewing-machines)
round the fly-wheel and driving pulley, then by means of
two thin wires, which \ve will screw into the hous of the
binding-screws just arranged, we couple up the brushes to
our galvanometer ($ 3), and rotate the handle of the fly-
wheel gently, in the direction we intend to work the machine
for the future.
A deflection of the north pole of the needle, either to right
or left, shows us in which direction the current is traveling ;
we carefully note, and mark with a paper label, which is the
binding-screw which is sending the positive current (which if
coupled to the wire over the needle, causes the north pole to
turn to the left), since this is the binding-screw which must
substitute the positive pole of the battery, and to which we
must attach the wire which comes from the S limb of our
dynamo.
§ 40. Two binding-screws are now to be inserted into the
baseboard, to which the wires proceeding
from the limbs of the field-magnet must be
clamped. These should be placed about
i l/z inches from he side of each limb, the
wires proceeding therefrom being denuded
of their covering and sandpapered at the
extremities where they are clamped to the
binding-screws. These binding-screws (as
also those connected with the brushes)
should, for the convenience of being able to
couple up at one and the same time two or
more wires, be of the pattern shown at Fig.
35, in which case the extremities of the
field-magnets may be also formed into rings,
as sho\vn at Fig. 34(7, and either clamped
down to the baseboard by passing the long
screw c (Fig. 34) into the ring, or the nut
p. a having been removed for the time being,
* ^9* the ring may be slipped over the screw b,
& and then clamped by the nut a. &
Cor.nection is now to be made between the binding-screw
attached to" the current-sending or positive brush (the one
529
which we have marked with a paper label), and the binding-
screw coupled to the wire, starting from the inside of the
limb of the field-magnet (see Fig. 31, c] by means of a short
length of No. 16 copper wire, well cleaned, bent into rings at
the ends, and clamped down as advised above.
If all the instructions have been carefully carried out,
more especially those contained in the last six paragraphs,
we shall find that on rotating the flywheel a powerful current
will flow between the two remaining binding-screws — viz.,
the one connected with the outside wire of the field-magnets,
and the other with the negative brush of the commutator £
current which will be sufficient to heat to bright redness q.%
inches to 5 inches of No. 42 platinum wire, or to light lour
5-candle power lamps, arranged in parallel arc.
The current actually flowing
through the circuit (the number of
amperes) will naturally depend
largely on the resistance interposed
between the poles — that is to say,
between the binding-screws/ con-
nected with the outside wire of the
field-magnet, and the negative brush
of the commutators respectively;
and since the magnetism of the
field-magnet depends entirely on the
amount of current flowing around
it, and this again influences the cur-
rent set up in the armature, it is
evident that every variation in the
resistance or the interpolar or out-
side circuit will produce a corres-
ponding variation in the current, if
the dynamo be connected up as
above described; and that a very
much larger current will traverse the
circuit when the resistance is small than when the resistance
is great. When the machine is doing its best work — that is
to say, when the resistance of the interpolar is equal to the
internal resistance of the machine — the current is equal to
that of eight or ten Bunsen's cells against an equal resist-
ance. * Sometimes it is necessary to send the current through
a greater resistance; in this case, in order not to weaken too
greatly the magnetism of the field-magnet by diminishing so
530
greatly the current, it is necessary to shunt off a portion of
the current, and send it round the limbs of the field-magnet
by another circuit, which diminishes the total resistance.
To render this clearer, let us suppose that we wish to light
up four five-candle lamps, having each an approximate resist-
ance of eight ohms, and requiring a current of about one
ampere each to cause them to give out their proper light. If
we arrange them in series, as in Fig. 36, #, when the total re-
sistance is the sum of their separate resistances = thirty-two
ohms, then, as the electromotive force of our machine when
at best is about ten \olts, so ^ represents the current flow-
ing through the lamps, supposing even that the dynamo lost
no power by the diminution of current (which it does to a
very great evcent), arid this current is not sufficient to light
the lamps. Hut if we arrange the lamps in parallel arc, as at
Fig, 36, />, then the total resistance falls to a quarter of one
single lamp — that is to say; it is
equal to two ohms only; hence the
currrent now flowing becomes
£fl = 5 amperes, and this divided
among the four lamps gives l*^
amperes each, which is ample.
Again, we find that coupling up
one single lamp to the dynamo
presents too great a resistance, so
that no light is given off, since not
sufficient current can pass round
the field-magnets to give an elec-
tromotive force of ten volts. But
if we insert a " shunt," consisting
of about a dozen inches of No. 30
iron wire between the two binding-
screws aforesaid, as shown at Pig.
37, and then connect the lamp also
to the said screws or terminals,
more current circulates round the
field-magnets, since two roads are
now open to the current, the field-
magnet becomes more powerfully
magnetic, and in its turn induces
a much more powerful current in
the armature, and so on until
current enough is produced to
531
light up the lamp. The resistance of the "shunt" to be
inserted between the terminals, to produce the best result,
will depend on the resistance of the interpolar. If this
latter be low, no " shunt " (or one of very great resistance)
will be required; but if the resistance of the interpolar be
very high, the resistance of the " shunt " must be corre-
spondingly low, or else not enough current will pass to
magnetize the field-magnet, and the dynamo will give no
current.
Fig. 38 represents the dynamo complete.
The machinist, mechanic, engineer, artisan, student or
schoolboy who has not only carefully read the preceding
pages on the dynamo, but has made, or attempted to make,
a machine by closely following the instructions, will have ac-
quired a knowledge of the rudiments of electrical science
which will enable him to explore still further into this fasci-
natrhg branch of the mechanical arts. This book is merely
designed to start the explorer on his interesting journey;
new discoveries, new inventions, and new surprises are daily
events in the electrical world; but, the fundamental prin-
ciples, the foundation laws, never change, and, wHh a fair
understanding of the underlying structure, the growing fabric
can be watched with satisfactory understanding.
The wide-awake mechanic will endeavor to keep abreast
with the times. He will be quick to note any novel dis-
covery, any important innovation, and in no branch of his
art are the possibilities of world-thrillinp- sensations greater
than in the electrical field.
Suppose, then, that you have made a dynamo, such as
described in this article ; suppose that you have it in active
operation, and it is giving you a current equal to eight or ten
Bunsen's cells ; you have an instrument which will be of the
highest value to you in your future researches ; instead of
finding the study a laborious grind, a dry, musty, brain
killer, you will find yourself fascinated with the opening
pages of the mysterious book when it is read by the light of
the electrical current generated by the dynamo made by the
skill of your own hands.
Too much value cannot be given a knowledge of the science
of electricity and its application to the mechanical arts, in-
creasing every day, will bring it in contact with every
mechanic and artisan in the country. Make a dynamo as
described, study as you make, and you will be able to keep
abreast of the times.
532
MANAGEMENT OF DYNAMOS.
The use of dynamos is becoming so general for electric
lighting and power that the following hints on the manage-
ment and care of dynamos may be of use to engineers, es-
pecially as the care of the dynamo is usually placed in the
hands of the engineer, and the machine placed in the engine-
room.
Before the dynamo is started for its day's run all the lubri-
cators should be rilled up. For this purpose none but cop-
per oil-cans should be used.
Next in order, the brushes should receive attention, and
should be carefully examined to see that they are properly
trimmed and thoroughly well screwed up to their holders.
If the brushes touch at a bevel angle, they should be oc-
casionally trimmed with a file, so that they will preserve an
even bearing upon the commutator. To do this properly the
brushes should be removed from the machine.
Never leave files or iron tools near the dynamo. If the
machine is in a shop where iron filings are flying about it
should be examined frequently to see if any filings have been
attracted, and if any are found they should be removed.
It is always best, if the dynamo is of necessity placed in
such a position, that it should be boxed in as completely as
possible.
After the machine has been started the brushes should be
put down; when the run is over the brushes should be raised
before the engine is stopped.
The commutator must be kept clean and bright and free
from metallic dust of any kind. It should be occasionally
wiped with a clean rag (never use waste), very slightly
smeared with oil or vaseline; should the brushes press too
heavily it will be worn into ruts, should they not press
firmly enough its segments will v/ear unequally along their
edges.
As soon as the dynamo is started the brushes should be
carefully so rocked that they touch at the neutral points; if
this position is not carefully observed the sparking may
rapidly ruin the commutator.
533
ELECTRICITY SIMPLIFIED.
No one knows what electricity really is. It seems, how-
ever, to be present everywhere. In the air, in the earth, in
the water, in trees, animals, man, fishes, metais, everywhere,
but no one can tell what it is, We know what steam is, for
we can divide it into its various parts. We know what a gas
is, for we can smell it, or taste it, or weigh it We
know what the air is; but we cannot see electricity, it has no
taste, it has no weight, no substance, but it is called a force,
which is made known to us by the peculiar fact that it willat-
tract or repel.
For instance, if you take a piece of glass — a small glass
rod or tube, and a piece of sealing-wax, and bring them near
some small scraps of paper, or shreds of cotton, a feather, or
gold leaf, or bran, you will not notice anything particular.
There will be no movement of any kind. But, suppose you
rub the glass and the sealing-wax briskly with a piece of dry
woolen cloth, then bring them near the light substances men-
tioned, you will find that the paper, or cotton, or gold leaf,
or bran, or feathers, will spring or jump toward the glass rod
or sealing-wax, even if quite a little distance is between them,
and will cling to the glass and wax.
You will further notice, that, after a time, the paper, etc.,
will jump away (not simply/^//) from the glass, or wax, as if
they had been snapped off.
Thus, there was something happened when the glass or
\vax was rubbed by the woolen cloth, something which gave
the glass or wax the property of attracting the paper, etc.
and afterward of repelling or casting off the same paper, etc.
This something was the electricity excited by the friction
between the glass or wax and the woolen cloth.
The writer of this article is smoking an ordinary pipe,
which has an amber mouth piece. He first wiped the moist-
ure from the amber, and then rubbed it for a few seconds
upon the green cloth of his desk, and, bringing it near some
little bits of paper, he found that the paper sprang and
remained upon the amber, ai?d, not only that, but the bit of
paper next to the amber attracted another bit of paper, and
that second piece another, until three little bits of paper, like
a chain, were hanging from the amber.
First, the amber was electrified, then each bit of paper, as
534
it came in contact with the electrified amber, became electri-
fied, and attractec another bit to itself. Now, there are two
kinds of electricity, positive and negative. The positive at-
tracts and the negative repels. This last statement can be
easily proved. Make two little balls from the pith of the
elder bush, or any other plant that has a dry, light pith.
When quite dry, fasten a fine silk thread to each pith ball,
and suspend them from some convenient point so they will
swing freely.
Electrify the sealing-wax with the woolen cloth, but, elec-
trify the glass rod with a piece of soft silk. Touch one pith
ball with the wax, and it will follow it for a moment and then
shoot away, just as the paper did. At the same time touch
the other pith ball with the glass and it will do the same
thing. If you bring the wax and glass nearer the pith balls
after they have been repelled, you will notice that they will
keep away from them. Now quickly change the wax and
glass, so that they will touch the pith ball that was first at-
tracted and then repelled by the glass, and you will see that <
the wax will attract it, and, if you touch the other pith ball
with the glass, it will be attracted also.
If you have taken the trouble to try this simple experi-
ment, you have learned that there is a positive electricity, or
the electricity that attracts, and a negative electricity, or the
electricity that repels.
You have also learned that the ball which was repelled by
the glass was attracted by the sealing-wax, and the ball that
was repelled by the sealing-wax, was attracted by the glass.
This proves that the electricity developed on glass is differ-
ent in kind from that developed on sealing-wax, and by re-
peating the experiment with other substances, it will be found
that all electrified bodies act like either the glass or the sealing-
wax.
There is another thing, two bodies charged with (or hav-
ing) positive electricity will repel each other, and the same
thing will happen if the two bodies are charged with negative
electricity, but, if one is charged with positive, and the other
with negative electricity, they will be attracted t© each other.
The electricity which is excited by rubbing two substances
together is c&lle&frictional electricity.
It has been shown by the above experiments that an elec-
trified substance can impart electricity to another. This is
called conduction. It is not necessary that the bodies should
535
touch. They may be connecter5 by a copper wire or a flax
thread. But, if connected by a silk thread, or a piece of rub-
ber, the electrified body will not electrify the other. Some
substances transmit electricity readily and others do not,
Those that offer little resistance to the passage of electricity
are called conductors; those that offer great resistance are
called non-conductors or insulators. Conductors which are
held up, or wrapped in non-conductors are said to be insu-
lated. Silver, copper and iron are conductors. Rubber,
gutta-percha, glass, porcelain and silk are non-conductors or
insulators. A copper wire, if wrapped in silk or rubber,
would be insulated.
For practical work, conductors are made of wire, either
copper or iron, usually having a covering made of woven silk
or cotton.
Frictional electricity is generated, for purposes where a
large quantity is needed, by electric machines, which con-
sists of a circular glass plate from one to four feet in diam-
eter, that is turned by a crank. Against the sides of this plate
are cushions made of silk or leather, coated with mercury.
On turning the crank, the glass plate revolves between the
silk cushions and is electrified. The electricity is gathered or
caught by metal points called combs, and is carried off by
conductors.
Electricity is also developed by chemical action. AH chem-
ical changes produce electric action. This is true whether the
substance is a solid, liquid or gas, but the chemical action
between liquids and metals gives the most satisfactory result.
Electricity thus developed is called the Voltaic or Galvanic
electricity. As was said before, we do not know just what
electricity is, but we do know that by combining certain
liquids and metals, or by making certain chemical combina-
tions, we can make all the electricity we want.
If we take a strip of copper and one of zinc, and place
them in a glass jar which contains some dilute sulphuric acid
(that is, water which has had sulphuric acid put in it), keep-
ing the zinc and copper separated, but connecting them above
the glass jar by a wire conductor, we will have a current of
electricity produced. In fact, two currents, opposite in kind
and direction, are produced— but, remember that, whenever
the direction of the electric current is referred to, it means
the direction of \he positive current.
It is necessary, for the production of an electric current :n
536
this way, that the liquid should have a greater action upon
one metal than upon the other. The metal which is most
vigorously acted upon by the acid is called the positive
plate (it generates jQr& might say, the electricity), the other
is the negative plate (it collects the electricity). So the cur-
rent starts from the positive plate, through the liquid to
the negative plate, then out of the glass jar through the
wire joined to the negative plate, and back through the
other wire to the positive plate. In the apparatus de-
scribed above(called a galvanic or voltaic element or cell)
the zinc is ^& positive plate, copper the negative plate.
The wires attached to the copper and zinc are called
electrodes or poles. The electrode attached to the copper
plate (which is the negative) is called the positive^ elec-
trode. The one attached to the zinc plate (which is the
positive plate), is called the negative electrode.
When two or more voltaic or galvanic elements(or cells)
are connected together, the apparatus is called a galbanic
or voltaic battery. In a battery the positive plate of one
cell is connected to the negative plate of the next cell, and
so on. When this is done, they are said to be coupled in
series. Sometimes all of the positive plates are connected
by wire, and all of the negative plates by another wire.
The cells are then said to be joined in ' ' multiple arc. ' '
Batteries for producing electricity are divided into two
classes, called ' 'open circuit" batteries, and "closed cir-
cuit' ' batteries. The open circuit batteries are used when
the electricity is not required constantly, but is used for a
short time at different periods. Such batteries are used
with telephones, electric bells, hotel annunciators, etc.
Closed batteries are used where the work is continu-
ous, as for electric lights, motors, etc.
(As galvanic cells can be readily purchased, and are not
expensive, it is recommended that a cell for open circuit
and one for closed circuit be purchased. For open circuit
buy one of the following makes: Leclanche cell, or the
Law; for closed circuit, the Grenet. These cells can now
be bought of any electric supply store).
Batteries as described, generating or producing elec.
tricity by the action and combination of chemicals
liquids and metals, are called "Primary Batteries"
There is another style of batteries, called Secondary or
Storage batteries. A secondary battery does not of itself
537
make an electric current, but is used to store up and hold the
energy of an electric current, which is led to it from a
primary battery or a dynamo. The electrical energy can
then be kept until it is wanted for use.
A secondary or storage battery usually consists of a glass
jar, holding plates, made of lead, and some water, which is
made slightly acku There are always two lead plates in a
secondary battery, but there may be any number above that,
and these plates are called electrodes. Upon the positive
electrode is spread a paste made of red lead. Upon the neg-
ative electrode is spread a paste made of litharge.
When the plates are thus prepared, they are put into the
acidulated water (which is held by the glass. jar), and a wire
from each plate is connected with conductors from a dynamo
or a primary battery. When all is ready for charging, the
current is turned on, and enters by one plate, coming out by
the other.
The electric current, of course, meets with some resistance
from the plate and the paste, and this resistance causes it to
work upon the paste in such a manner that a chemical change
is made, that is, the paste on the positive electrode has been
changed to peroxide of lead, and that in the negative electrode
into spongy lead.
When the current has passed from one plate to another in
this way for a time, the wires are disconnected from the
dynamo or primary battery.
As the acidulated water is still left in the glass jar, the
paste upon the plates begins to work to get back to its orig-
inal shape, and it is this, working that causes a current of
electricity, which will light lamps, run a motor or do anything
the current from the dynamo or primary battery would do.
After the paste has resumed its original form, the battery
is said to be discharged, and can then be again charged.
It is customary, in practical use of secondary or storage
batteries, to charge them from a dynamo. These batteries
are largely used for street car purposes. A motor is attached
to the axle of the car, and is energized by the storage bat-
teries placed beneath the seats, the batteries having been
charged from a dynamo located at the terminus of the road.
In the article on "How to Build a Dynamo," commencing
on page 478, the magnetizing effects of an electric current
are explicitly explained.
Electricity, although it has no weight or tangible form, is
measured as accurately as is steam, or air, or coal.
The three measurements most commonly used are
The Volt;
The Ampere;
The Ohm.
THE VOLT is the practical unit of measurement of press-
ure. That is, " volt " bears the same relation to electricity
as " pounds " does to steam. When we speak of steam in
a boiler or in the cylinder of a steam engine, we say: " There
is a pressure of ten or fifty or a hundred pounds to the
square inch," and steam pressure is calculated and measured
in pounds; thus, a " pound " is the unit of pressure or
intensity.
Now, electricity moves with a certain force and pressure;
this force is called the electro-motive force (represented by the
letters E. M. F»), and the unit of pressure or intensity of this
force, is called a volt. Thus we say that a dynamo has an
electro-motive force of 117 volts, or that the intensity of a
galvanic cell is ll/2 volts, etc.
Suppose, instead of steam, we had used the water which
comes into the house from the water-works, as an illustra-
tion. That water comes in through pipes and is forced
through these pipes by pumps.
Now, the water comes with a pressure of so many pounds
to the inch, and " pound M is the unit by which this pressure
is measured. The water would not flow through the pipes
unless it was pushed or forced through, neither would elec-
tricity flow through the wires without there was pressure
back of it, and this pressure is measured in volts.
THE AMPERE is the practical unit of the rate of flow of
electricity. Electricity flows through the wire at a certain
pressure, just as water flows through pipes at a certain
pressure. Now, if we wanted to speak of the water coming
through the pipes, we would say that the water was flowing
at the rate tf/five gallons per minute, and if the pressure on
the water was ten pounds, we would say that the water was
flowing at the rate of five gallons per minute, at a pressure
of ten pounds to the inch.
In speaking of the electric current, we say, " that a certain
current of electricity is flowing at the rate of one ampere^
acted upon by an electro-motive force of 90 volts, or a
lamp requires a current of two amperes •, at a pressure of 100
volts to light it.
539
Thus, the volts of pressure forces the current to flow through
the wires at a certain rate per second, and this rate is called
the ampere.
THE OHM (pronounced like " ome " in home) is the practi-
cal unit of measurement of resistance.
Electricity is conducted or carried from one place to
another, for the purpose of telegraphing, telephoning, light,
power, etc., by means of wires, made of copper or iron.
These wires do not permit the current to flow through
them without hindrance. There is always a certain amount
of resistance to the current, and the smaller the wire, the
more resistance there is. Sometimes the current is too strong
for the wire, and it becomes hot, gets red, and burns up.
That is, the wire is too small for the volts pressure, and
amperes of current of electricity, and the current, trying to
get through, and fighting to overcome this resistance, becomes
red hot and then may melt.
This resistance is measured by the ohm; thus, a copper
wire of such a size has a resistance of so many ohms.
RULES AND REGULATIONS.
FOR
PROPERLY WIRING AND INSTALLING ELECTRIC LIGHT
PLANTS.
The following rules and regulations for the prevention of
fire risks arising from electric lighting, were issued by the
Society of Telegraph Engineers and Electricians of England,
and every person, connected with an establishment using
electric lights, whether owners or employes, should care-
fully read them, and be governed thereby :
The chief difficulties which beset the electrical engineer are
internal and invisible, and can only be effectually guarded
against by testing with special apparatus, and electric cur-
rents. They arise from leakage and bad connections and
joints, which lead to waste of energy and the production of
heat to a dangerous extent.
MOISTURE DANGER. — The necessity for guarding against
the presence of moisture, which leads to loss of current and
to the destruction of the conductors and apparatus, by cor-
rosion and otherwise, cannot be too strongly urged.
EARTH DANGER. — Injudicious connections of any part of
the circuit with the " earth" tend to magnify every other
source of difficulty and danger.
IGNORANCE AND INJUDICIOUS ECONOMY. — Many of the
dangers in the application of electricity arise from ignorance
and inexperience on the part of those who supply and fit up
inadequate plants, and frequently from injudicious economy
on the part of the user.
SAFETY IN CONSULTING EXPERIENCED ENGINEERS. —
The greatest element of safety is, therefore, the employment
of skilled and experienced electrical engineers to specify the
method in which the work is to be done, and the quality of
the materials to be employed, and to supervise the execution
of the work.
CONDUCTORS.
1. SECTIONAL AREA. — Conductors (wires) must have a
sectional area and conductivity so porportioned to the work
they have to do, that, if. double the current proposed is sent
through them, the temperature of such conductors shall not
exceed 150° Fahr.
2. ACCESSIBILITY. — The conductors, or their coverings,
should be placed in sight, if possible, and they should always
be as accessible as circumstances will permit.
3. INSULATING. — Within buildings they should be insu-
lated; and this rule applies equally to all conductors and
parts of fittings which may have to be handled.
4. MAXIMUM TEMPERATURE. — Whatever insulating mate-
rial is employed it should not soften until a temperature
of 170° Fahr., has been reached, and, in all cases, the material
must be damp-proof.
5. CASINGS. — When wires pass through roofs, floors,
walls or partitions, and where they cross, or are liable to touch
metallic substances, such as bell wires, iron girders, or, pipes
they should be thoroughly protected by suitable additiona'
covering; and, where they are liable to abrasion from an
cause, or the depredations of rats or mice, they should be
encased in some suitable hard material.
6. DISTANCE APART. — Conductors should be kept as far
apart as circumstances will permit, the spacing between them
being governed by their potential difference.
7. INFLAMMABLE STRUCTURES. — When conductors are
carried in very inflammable structures, precaution should be
taken to isolate them therefrom.
8. METALLIC ARMOR. — Conductors which are protected
on the outside by lead, or metallic armor of any kind, require
the greatest care in fixing, on account of the large conducting
surface which would become connected to the core in the
event of metallic contact between them.
9. JOINTS.— All joints must be mechanically and electrically
perfect, to prevent heat being generated at these points.
When soldering fluids are used in making joints, the latter
should be carefully washed and dried before insulation is
applied.
10. GAS AND WATER PIPES. — Under all circumstances
complete metal circuits must be employed. Gas and water
pipes must never form part of a circuit, as their joints are
rarely electrically good, and therefore become a source of
danger.
11. OVERHEAD CONDUCTORS. — Overhead conductors,
whether passing over or attached to buildings, must be insu-
lated at their points of support.
Precaution must be taken to obviate all risks of short-cir-
cuiting, where they are likely to touch a building, or other
overhead conductors and wires, either by their own fall or
by being fallen upon by other conductors.
12. LIGHTNING PROTECTOR. — In the case of overhead
wires, every main should have a lightning protector at each
point, where it enters or branches into a building.
542
13. INSULATION RESISTANCE. — The insulation of a system
of distribution should be such, that the greatest leakage from
any conductor to earth (and, in case of parallel working, from
one conductor to the other, when all branches are switched
on, but the lamps, motors, etc., removed), does not exceed
one five thousandth part (Q^QQ) of the total ciirrent in tended for
the supply of the said lamps, motors, etc., the test being
made at the usual working electro-motive force.
SWITCHES.
14. CONSTRUCTION AND ACTION. — Every switch or com-
mutator should be of such construction as to comply with
the following condition, namely: That when the handle is
moved or turned to or from the positions of " on " and " off,"
it is impossible for it to remain in any intermediate position,
or to permit of a permanent arc, or heating.
15. INSULATED HANDLES.— The handles of every switch
must be completely insulated from the circuit.
16. MAIN SWITCHES, POSITION OF. — The main switches
of a building should be placed as near as possible to the point
of entrance of the conductors, or to the generators of the cur-
rent if they are within the building itself Switches should
be provided on both leads.
17. SWITCH BOARDS. — Switch boards should bear clear
instructions for their use by the inexperienced.
ELECTRICAL FITTINGS GENERALLY.
18. BASES. — Switches, commutators, resistances, bare
connections, lamps, etc., must be mounted on incombustible
bases; cut-outs, mounted on bases of wood, rendered unin-
flammable, are admissible; vulcanite bases are undesirable in
damp situations. The cracking of porcelain and earthen-
ware fittings is a source of danger which can be avoided by
precautions in fixing.
CUT-OUTS.
19. IMPERATIVE USE OF. — All circuits should be protected
by cut-outs ; and all leads from the mains, or small conductors
from larger ones, must be fitted with cut-outs at their branch-
ing points
20. SITUATION.— Where fusible cut-outs are used, the
section should be so situated within its frame that the fused
metal cannot fall where it may cause a " short circuit " or an
ignition.
21. FOR ( + ) AND ( — ) MAINS. — For all main conductors
a cut-out should be provided for both the " flow " and
" return ; " and the two fusible sections must not be in the
same compartment.
22. FOR PORTABLE FITTINGS. — The flexible wires of por-
table fittings must in all cases be protected by cut-outs at
their fixed points of connection.
ARC LAMPS.
23. GLOBES, ETC. — Arc lamps must always be guarded by
globes, netted or otherwise, so to prevent danger from
ascending sparks, or from falling glass and incandescent
pieces of carbon.
24. INSULATION OF PARTS. — All parts of the lamps and
lanterns which are liable to be handled (except by the persons
employed to trim them), should be insulated.
THE DYNAMO.
25. INSULATION, SITUATION, ETC.— The armatures and
field magnet coils should be thoroughly insulated. Dynamos
should always be fixed in dry places, and they must not be
exposed to dust flyings or other industrial waste products
carried in suspension in the a.r. They should not be per-
544
mitted in the working rooms of mills, where the liability to
such dangers exists, or, where any inflammable manufactures
are carried on, or inflammable materials are stored.
26. MOTORS. — Motors should be subject to the same con-
ditions; but when it is necessary to use them in positions such
as those above referred to, they must be securely cased in,
such cases having a non-combustible lining.
BATTERIES.
27. INSULATION. — Both primary and secondary batteries
should be placed and used under the same precautions as pre-
scribed for dynamos; and the room in which they are placed
should be well ventilated. The batteries themselves must be
well insulated.
MAINTENANCE.
28. TESTING. — The value of frequently testing and inspect-
ing the apparatus and circuits cannot be too strongly urged as
a precaution against fire. Records should be kept of all tests,
so that any gradual deterioration of the system may be
detected.
tu
29. CLEANLINESS. — Cleanliness of allaparts of the appara-
is and fittings is essential to good maintenance.
30. REPAIRS. — No repairs or alterations must be made
when the current is " on."
GENERAL.
All the above rules for the reduction to a minimum of the
risks from fire, are also applicable in principle to installations
of electricity for other uses than that of lighting : they also
include precautions necessary to avoid risks of injury to per-
sons, whether the conductors and apparatus are situated
inside or outside a building.
545
A FEW POINTS FOR INVENTORS REGARDING
PATENTS.
The progressive mechanic is always an inventor. He
may not have his invention patented, but he is constantly
planning ways and means to improve the mechanism
and tools which he uses, or devising better methods of
working and manufacturing.
To those mechanics who deem their invention patent-
able, the following pointers will be of value:
It is always well to thoroughly investigate the patent
office reports before undertaking the expense and trouble
incident to the application and issue of patents.
In nearly every town, of any size, bound volumes of
patent office reports, with the all-important index, may
be found in the Public Library.
Thoroughly search and examine these reports before
you apply for a patent. It may save you time and money.
CORRESPONDENCE. — All business with the patent
office, which is located at Washington, D. C., should
be transacted in writing.
No attention is paid to any oral instructions or petitions
All office letters must be sent in the name of the
" Commissioner of Patents. ' '
All express, freight and postage charges must be fully
prepaid.
A separate letter should in every case be written in re-
lation to each distinct subject of inquiry or application.
When a letter concerns an application, it should state
th e name of the applicant, title of the invention, the serial
number of the application , and the date of filing of same.
When a letter concerns a patent, it should state the
name of the patentee, the title of the invention and the
number and date of the patent.
APPLICANTS. — A patent may be obtained by any per-
son who has invented or discovered any new or useful art,
machine, manufacture or composition of matter; ,any new
and useful improvement thereof, not known or used by
others in this country; not patented or described in any
publication, in this or any foreign country, before his
invention or discovery thereof, and not in public use or on
546
sale for more than two years prior to his application, unless
the same is proved to have been abandoned; and by any per-
son who, by his own industry, genius, efforts, and expense,
has invented and produced any new and original design for a
manufacture, bust, statue, alto-relievo or bas-relief; any new
and original design for the printing of woolen, silk, cotton, or
other fabrics; any new and original impression, ornament,
pattern, print, or picture to be printed, painted, cast, or
otherwise placed on or worked into any article of manufact-
ure; or any new, useful and ornamental shape or configura-
tion of any article of manufacture, the same not having been
known or used by others before his invention or production
thereof, nor patented nor described in any printed publica-
tion, upon payment of the fees required by law and other
dfoe proceedings had.
In case of death of the inventor, the application may be
made by, and the patent will issue to, his executor or admin-
istrator.
In case the patent is to be assigned, the application and
path must be made by the actual inventor (not the assignee),
if alive, or his administrator or executor, if inventor is dead.
Joint inventors are entitled to a joint patent; neither can
Claim one separately.
Foreign patents will not prevent an inventor from obtain-
ing one in the United States, unless the invention will have
been in public use in the United States more than two years
prior to the application.
But the patent, 'if issued, will expire at the same time as
the foreign patent.
THE APPLICATION. — Applications for letters patent must
be made to the Commissioner of Patents.
. A complete application comprises tfa petition, specification,
oath, and drawings (or the model or specimen if required),
and the first fee of $15.00.
The petition, specification and oath must be written in the
English language.
The application must be completed and prepared for ex-
amination within two years after filing of the petition, other-
wise it will be regarded as abandoned, unless it is shown, to
the satisfaction of the commissioners, that the delay was un-
avoidable.
547
THE PETITION. — The petition is a communication duly
signed by the applicant and addressed to the Commissioner of
Patents, stating the name and residence of the petitioner, and
requesting the grant of a patent for the invention therein
designated by name, with a reference to the specifications for
a full disclosure thereof.
The following form will serve as a model:
To the Commissioner of Patents-
Your petitioner (name), a citizen of the United States^
residing at (name of town), in the county of (name of county),
and State of (name of State), prays that letters patent be
granted to him for the improvement in (subject of invention)
set forth in the annexed specification.
(Arame of Inventor.)
THE SPECIFICATION. — The specification is a written
description of the invention or discovery, and of the manner
and process of making, constructing, compounding and using
the same, and it must be written in such full, clear, concise
and exact terms, that anybody skilled in the art or science
to which it appertains, or with which it is most nearly con-
nected, can make, construct, compound and use the same.
It must conclude with a specific and distinct claim or
claims of the part, improvement or combination which the
applicant regards as his invention or discovery.
The following order of arrangement should be observed in
framing the specification:
1. Preamble, giving the name and residence of the applicant
and the title of the invention; and if the invention has been
patented in any country, a statement of the country or coun-
tries in which it has been so patented, giving the date and num-
of each patent. If the patent has no number it will be so
stated under oath.
2. General statement of the object and nature of the inven-
tion.
3. Brief description of the drawings, showing what each
view represents.
4. Detailed description, explaining fully the alleged inven-
tion, and the manner of constructing, practicing, operating
and using it.
5. Claim or claims.
6. Signature of inventor.
7. Signature of two witnesses.
548
^ The detailed description must set forth the precise inven-
tion for which a patent is claimed, fully explaining the prin-
ciple thereof and the best mode in which the applicant has
contemplated applying that principle^so as to distinguish it
from other inventions.
Where there are drawings, the description will refer by
figures to the different views, and by letters or figures to the
different parts.
In every original application the applicant must state, under
oath, whether the invention has been patented to himself or
others, with his consent and knowledge, in any country; if so,,
the names of the country or countries, the date and numbev
of each patent must be given.
Two or more independent inventions cannot be claimed in
one application.
The specification must be signed by the inventor or by his
executor or administrator, and two witnesses must attest the
signature. Full names must be given, and all names must be
legibly written.
The specification (and in fact all documents relative to the
invention) must be legibly written, on but one side of the
paper, otherwise the office may require that they be printed.
All interlineations and erasures must be clearly marked in
marginal or foot notes written on the same sheet of paper.
Legal cap paper, with the lines numbered, is best.
Preserve a wide margin on the left hand-side of the page.
THE OATH. — The oath must follow the specification, and
should be as follows :
STATE OF , County of , ss. :
, the above-named petitioner, citizen of
-, and resident of , in the county of -
and State of , being duly sworn (or affirmed), depose
and say that verily believe to be the original,
first and inventor of the improvement in
described and claimed in the foregoing specification; that
the same has not been patented to , or to others with
knowledge or consent, except in the following coun-
tries: , , — ; that the same has not to
knowledge been in public use or on sale in the United States
for more than two years prior to this application, and
549
do not know and do not believe that the same was
ever known or used prior to invention thereof.
(Inventor's name in full) .
Sworn to and subscribed before me this day
of , 1 8 .
[L. s.] (Signature of justice or notary) ,
(Official character) .
N. B.: If not previously patented, erase the words,
"except in the following countries/' and insert the words
" in any country. "
If the applicant is an alien, the oath will show of what
foreign state or sovereign he is a citizen or subject.
If the applicants claim to be joint inventors, the oath will
show " that they verily believe themselves to be the original,
first and joint inventors, etc. "
THE DRAWINGS. — Applicants for patents must furnish
drawings when the nature of the case admits.
Drawings must be signed by the inventor or his attorney,
and attested by two witnesses.
The drawing must show every feature of the invention
covered by the claims.
When the invention consists of an improvement of an old
machine, the drawing must exhibit, in one or more views, the
invention itself, disconnected from the old structure, and
also, in another view, so much of the old structure as will
suffice to show the connection of the invention.
The following rules are rigidly enforced by the patent
office :
1. Drawing*, must be made upon pure white paper, of a
thickness corresponding to three-sheet Bristol board.
The surface of the paper must be calendered and smooth.
India ink alone must be used, to secure perfectly black and
solid lines.
2. The size of a sheet on which a drawing is made must be
exactly 10 by 15 inches.
One inch from its edge, a single marginal line to be drawn,
leaving the " sight," precisely eight by thirteen inches.
Within this margin, all work and signatures must be
included.
One of the shorter sides of the sheet is regarded as its top,
and measuring downward from the marginal line, a space of
550
4
not less than one and one-fourth inch is to be left blank for
the heading of title, name, number and date.
3. All drawings must be made with the pen only.
Every line and letter (signature included) must be absolu-
tely black.
These directions apply to all lines, however fine, to shad-
ing, and to lines representing cut surfaces in sectional views.
All lines must be clear, sharp and solid, and they must not
be too fine or crowded.
Surface shading, when used, should be open.
Sectional shading should be made by oblique parallel lines,
which may be about one-twentieth of an inch apart.
4. Drawings should be made with the fewest lines possible
consistent with clearness.
Shading (except on sectional views) should be used only on
convex and concave surfaces, and then sparingly.
The plane upon which a sectional view is taken should be
indicated on the ground view by a broken or dotted line.
Heavy lines on the shade sides of objects should be used,
except when they tend to thicken the work and obscure letters
of referrance.
The light is always supposed to come from the upper left
hand corner, at an angle of forty-five degrees.
Imitations of wood or surface-graining should not be
attempted.
5. The scale upon which the drawing is made must be
large enough to show the mechanism without crowding.
If one sheet is not enough, use more.
6. Form the letters and figures of reference carefully;
make them, if possible, at least J/% of an inch in height.
Do not draw figures and letters on the lines of the
drawings.
Never place them in shaded places.
Never use the same letter or figure to represent more than
one part.
The signature of the inventor must be placed at the lower
right-hand corner of the sheet, and the signatures of witnesses
at the lower left-hand corner, all within the marginal lines.
The title must be written in pencil on the back of the
sheet.
Drawings should be rolled for transmission to the patent
office, never folded.
The patent office advises inventors to employ a competent
artist to make their drawings. The patent office will do the
work at cost.
THE MODEL. — A working model is often desirable in
order that the patent office may fully and readily understand
the precise operation of the machine.
It must not be over one foot in length, width or height.
It must be neatly and substantially made, of durable mate-
rial, metal preferred.
If made of wood, it must be painted or varnished.
Glue must not be used, but the parts must be constructed
to resist heat and moisture.
It must clearly exhibit every feature of the machine which
forms the subject of a claim of invention, but should not
include other matter than that covered by the actual inven-
tion or improvement, unless it is necessary for exhibiting the
invention in a working model.
ATTORNEYS. — It is always best to employ a competent
patent lawyer as attorney. The inventor can then be as-
sured that all the formalities and regulations of the Patent
Office are being complied with.
The lawyer will see that the drawings and models meet the
requirements of the Patent Office, and he can urge the matter
to a speedier termination than the inventor can do, if acting
himself.
CONSULT A GOOD PATENT LAWYER.
The Patent Office fee for filing each original appli-
cation for a patent is $15 °o
On issue of letters patent 20 oo
On filing a caveat ; 10 oo
On filing a disclaimer 10 oo
On filing application for re-issue of a patent 30 oo
On filing application for a division of a re-issue. .... 30 oo
On filing application for extension of a patent 50 oo
On granting extension 50 oo
552
HOW STEEL RULES ARE MADE.
There are few branches of the engineering trades that
require the exactness and precision requisite in the manufact-
ure of steel rules, standards, and measuring instruments.
Accuracy and reliability are the two absolute essentials. In
the general practice the steel blades, after being prepared by
being ground, glazed, and tempered, are coated by an acid-
resisting varnish, specially made to suit the requirements of
the trade, for upon this depends, in a great measure, the
clearness of the divisions when etched. The varnish being
dry, the blades are placed upon the table of a pentagraph,
which might well be termed a copying machine, as its work is
to transfer to the steel blades, in a diminished size, any marks,
letters, or figures that may be traced ftom the copy. The
latter is a plate of thin zinc, or any suitable metal, usually
four times larger than the rules to be made, the divisions,
figures, and letters all being made four times larger than they
are required to be when engraved upon the steel blades; the
•bject of this increased size being to diminish any imperfec-
tion that may exist upon the copy. There is a tracer con-
nected by a system of steel bands and pulleys to the table so
constructed as to move in two opposite directions at right
angles to each other. Above the table are fixed two rows of
holders, each having a diamond point; these holders are raised
and lowered at the will of the operator by a treadle, so that
both divisions, figures, and letters are traced from the copy
and transferred, in a diminished proportion, to the steel
blades. The diamond points being required only to cut
through the varnish, the blades are taken from the machine
and etched, the acid burning away the steel wherever the
diamond point has been traced.
WHAT INVENTION HAS DONE.
In the manufacture of boots and shoes, the work ot 500
operatives is now done by 100.
In making bread boxes, three workers can do the work of
thirteen box makers by old methods.
In cutting out clothing and cloth caps with discs, one
worker does the work of three by the old methods.
553
In leather manufacture modern methods have reduced the
necessary number of workers from 5 to 50 per cent.
A carpet measuring and brushing machine with one
operator, will do the work of fifteen men by the old methods.
In the manufacture of flour, modern improvements save
75 per cent, of the manual labor that once was necessary.
By the use of coal-mining machines, 100 miners, in a
month, can mine as much coal as 500 miners by the old
methods.
In making tin cans, one man and a boy, with modern
appliances, can do the work of ten workers by the old proc-
esses.
One boy, by machinery in turning wood-work and materials
for musical instruments, performs the work of twenty-five
men by the old methods.
The horse-power steam used in the United States on rail-
ways, steamers, and in the factories and mines was, in 1888,
12,100,000, against 1,610,000 in 1850.
In the manufacture of bricks, improved devices save one-
tenth of the labor; and in manufacturing of fire brick, 40 per
cent, of the manual labor is displaced.
534
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HOUSE FLAGS.
white and blue flag, with red penn
swallowtail flag, with white keystoi
e swallowtail flag, with red anchor
e, red border, three red crescent;
letters C. B.
flag, with yellow lion in centre,
e flag,red ball in corner,and the nam
flag, with blue and white ball in cen
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e and blue flag, with an anchor a
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flag, with square in upper corner
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e flag, key and anchor crossed in <
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white, and two green stripes, N. A
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BELL T1MK ON SHIPBOARD.
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Time, A. M.
,301 Bell 8.30
5.002 Bells 9.00
5-303 " 9-30
6.004 ; 10.00
6.305 " 10.30
7.006 " n.oo
7.307 " 11-30
8.008 " Noon
Time, P. M.
,.30 i Bell 8.30
5.002 Bells 9.00
5.303 " 9-30
6.004 : 10.00
6.305 " 10.30
7.006 " ii. oo
7-307 " 11.30
8.008 " ...Midnight
HOW TO DETECT GAS LEAKAGE.
In order to detect gas leakage, Dr. Bunte, in the
Canadian Magazine of Science^ suggests the use of paper
dipped in palladium chloride solution. Such paper changes
its color in presence of gas coming from the leaks imper-
ceptible by the odor, and which produce no effect upon the
earth covering the pipes. Dr. Bunte suggests the following
method of practically applying the test to street mains :
Above the pipes are excavated, at intervals of two or three
yards, holes twelve to sixteen inches deep, corresponding to
the joints and sleeves. In each opening is placed an iron
tube, half an inch in diameter, within which is a glass tube,
containing a roll of the test paper. The air from about the
main enters the iron tube, and the trace of gas which may be
present reveals itself by coloring the paper brown or black,
according to the quantity. If, after ten or twenty minutes,
the paper is still white, it may be certainly concluded that at
the point tested there is not the smallest escape of gas.
Various author-ities who have experimented with Bunte's
method certify vO its efficacy.
556
POINTERS ON SUCCESS IN BUSINESS.
Buy and sell for cash.
Don't try to start in a big way.
Morality is the basis of co-operation.
Require all employes who handle funds to give bonds.
Confidence in one another is the natural outgrowth of
sound morality.
By doing a cash business every workingman's dollar is
worth $1.10.
Co-operation will insure a good article, and honest weights
and measures.
Beware of credit. He is the undertaker who buries all
foolish co-operators.
Never imagine your work is done. Eternal vigilance is
the price of success.
The primary object of co-operation is to improve the
condition of producers.
Don't make your by-laws too long or technical, and com-
pel their close observance.
The backbiter and slanderer is the most dangerous per-
son you can get into a co-operative society.
^'Seeto it that your manager makes statements quarterly,
or as the by-laws provide, and be on hand to hear them, in-
stead of staying away and grumbling.
Keep clear of all political party manipulators ; long be-
fore you fully understand the science of industrial co-opera-
tion, you will know how to co-operate at the ballot box.
Intelligence, sobriety, industry and economy are indis-
pensable requisites of co-operators. Co-operation can do
nothing for the lazy, immoral or reckless, unless they reform.
Put your enterprise, no matter what it is, in the hands of
a man who understands the business. If you attempt to learn
co-operation and educate a manager in the conduct of the
business at the same time, you will fail.
When you select a manager let him run the business until
he demonstrates his incapability. More enterprises fail
through the meddling of a bad board in things they don't
understand than from any other single cause.
Take the bold step of gradually reducing stock.
Seize the right time for modifying your business with ad-
vantage.
Push your trade with energy and spirit, and by judicious
advertising.
Divide your risks as the insurance people do, so that in
*ase of failure you will not be much hurt .
557
In stock-taking let nothing but real value appear in the
balance sheet, and under rather than over value.
Let the benefit to accrue from vigorous use of the prun-
ing knife sustain you. It will come out all right in the end.
As a rule you lose people and their custom when they get
into your debt. If possible do a strictly cash business.
Strike off all customers who will not steadily pay monthly.
Keep strictly to this rule and you will have a healthy trade.
The true limits of credit may be seen from the etymology
of the word. It is a promise to pay something in the future.
When you have commenced a business go thoroughly into it.
Do not be ashamed of an honest business that is supporting
you. Make it honorable.
When an account is opened ask the parties to what extent
they wish to go and keep them to the amount agreed upon,
which, with their name, should be entered in the ledger.
VARIOUS LOCATIONS OF THE CAPITAL OF
THE UNITED STATES.
The capital of the United States has been located at dif-
ferent times at the following places: At Philadelphia
from September 5, 1774, until December, 1776; at
Baltimore from December 20, 1776, to March, 1777; at
Philadelphia from March 4, 1777, to September, 1777; at Lan-
caster, Pa., from September 27, 1777, to September 30, 1777;
at York, Pa., from September 30, 1777, to July, 1778; at
Philadelphia from July 2, 1778, to June 30, 1783; at Prince-
ton, N. J., June 30, 1783, to November 20, 1783; Annapo-
lis, Md. , November 26, 1783, to November 30, 1784;
Trenton from November, 1784, to January, 1785; New
York from January n, 1785, to 1790; then the seat of gov-
ernment was removed to Philadelphia, where it remained
until 1800, since which time it has been at Washington.
GROWTH OF THE UNITED STATES.
The United States has a population of at least 62,000,000
at this moment. This makes it second in this particular
among the great civilized nations of the world. Keeping in
view the ratio of growth of the countries named between
recent census periods, there are to-day about 88,000,000
inhabitants in European Russia, 47,000,000 in Germany, 40,-
000,000 in Austro- Hungary, 38,000,000 in France, 37,000,000
in Great Britain and Ireland, 30,000,000 in Italv. anJ. r??*
000,000 in Spain-
The population of none of the other countries in Europe
reaches 10,000,000 — Turkey's inhabitants outside of Asia
aggregating scarcely half that figure. Russia alone of the
great powers of Christendom exceeds the United States in
population. Even Russia must soon be left far in the rear.
July i, 1890, when the next national enumeration takes place,
the United States will have 67,000,000 inhabitants. It will
have 96,000,000 in the year 1900, and 124,000,000111 1910.
This computation is based on the average growth of the
country during the century. Employing a like basis for
Russia, that nation before 1910 will have dropped to second
place, the United States taking the first.
Forty years ago the United States stood sixth in point of
population among civilized nations of the globe and twenty
years ago it stood fifth. Twenty years hence it will stand
first.
THE NEW FORTH BRIDGE.
The new railroad bridge over the Frith of Forth, in
Scotland, to replace the one which went down with such
appalling results a few years ago, is now near completion, and
is described as one of the finest pieces of engineering in the
world. The chief engineer of the structure gives the follow-
ing "cold facts" regarding it: The total length of the
viaduct will be 8,296 feet, or nearly i^ miles, and there are
two spans 1,710 feet, two of 680 feet, fifteen of 168 feet
girders, four of 57 feet, and three of 25 feet, being masonry
arches. The clear headway for navigation will not be less
than 150 feet for 500 feet in the center of the 1,710 feet spans.
The extreme height of the structure is 361 feet above, and
the extreme .depths of foundation 91 feet below the level of
high water. There will be about 53,000 tons of steel in the
superstructure of the viaduct, and the material used through-
out is open-hearth of Siemens-Martin steel. That used for
parts subject to tension is specified to withstand a tensile
stress of 30 to 33 tons to the square inch with an elongation
in eight inches of not less than 20 per cent. ; that subject to
compression only a tensile stress of 34 to 37 tons per square
inch, with an elongation in eight inches of not less than 17
per cent.
Rochester, N. Y., has an electric-light plant which sup-
plies i, too arc and 1,025 incandescent lamps. The plant is
said to be the largest in the world run by water power-
559
"ANCIENT" WINTERS.
In 401 the Black Sea was entirely frozen over. In 763
not only the Black Sea, but the Straits of Dardanelle, were
frozen over, the snow in some places rising 50 feet high. In
822 the great rivers of Europe, the Danube, the Elbe, etc.,
were so hard frozen as to bear heavy wagons for a month.
In 860 the Adriatic was frozen. In 991 everything was
frozen, the crops totally failed and famine and pestilence
closed the year. In 1707 most of the travelers in Germany
were frozen to death on the roads. In 1 134 the Po was
frozen from Cremona to the sea, the wine sacks were burst,
and the trees split by the action of the frost with immense
noise. In 1236 the Danube was frozen to the bottom, and
remained long in that state. In 1316 the crops wholly failed
in Germany. Wheat, which some years before sold in
England at 6s. the quarter, rose to £2. In 1308 the crops
failed in Scotland, and such famine ensued that the poor were
reduced to feed on grass, and many perished miserably in the
fields. In 1368 the wine distributed to the soldiers was cut
with hatchets. The successive winters of 1432-3-4 were
uncommonly severe. In 1663 it was excessively cold. Most
of the hollies were killed. Coaches drove along the Thames,
the ice of which was n inches thick. In 1709 occurred very
clod weather ; the frost penetrated three yards into the ground.
In 1 726 booths were erected on the Thames. In 1744 and
1745 the strongest ale in England, exposed to the air, was
covered in less than 15 minutes with ice an eighth of an inch
thick. In 1808 and again in 1812*, the winters were remark-
ably cold. In 1814 there was a fair on the frozen Thames.
STRENGTH OF HORSES.
It is stated that, if one horse can draw a certain load over
a level road on iron rails, it will take one and two-thirds horses
to draw the same load on asphalt, three and one-third horses
to draw it on the best Belgian block, five on the ordinary
Belgian pavement, seven on good cobblestones, thirteen on
bad cobblestones, twenty on. an ordinary earth road, and forty
©n a sandy road.
THE LARGEST DAM IN THE WORLD.
The largest dam in the world is in California. It will be
700 feet long, 175 feet high, 175 feet thick at the base, 20
feet thick at the top, and the reservoir thus formed wild haw
& capacity of 32,000.000 gallon*
56o
THE LARGEST PONTOON BRIDGE IN
WORLD.
The pontoon bridge over the Missouri River at Nebraska
City is said to be the largest in the world. Its length across
the navigable channel is 1,074 feet, while the back channel is
traversed by a causeway 1,050 feet long, supported on cribs.
The charter for this bridge has been held for twelve years,
because of the difficulty of obtaining financial support for a
project that appeared so impracticable. It is stated that the
entire bridge was built in twenty-eight days, at a cost not
exceeding $18,000, by Col. S. N. Stewart of Philadelphia,
assisted by Gen. Lyman Banks, of Iowa. The draw is
V-shaped, with the apex downstream. It is operated by the
current and controlled by one man. The clear span is 528
feet, the largest in the world. The bridge was completed in
August, and is doing good service. It will be removed
during the ice season.
THE| BANK OF ENGLAND DOORS.
The Bank of England doors are now so finely balanced
that a clerk, by pressing a knob under his desk, can close the
outer doors instantly, and they cannot be opened again exc-ept
by special process. This is done to prevent the daring and
ingenious unemployed of the metropolis from robbing the
bank. The bullion departments of this and other banks are
nightly submerged several feet in water by the action of the
machinery. In some bank* the bullion department is con-
nected with the manager's sleeping room, and an entrance
cannot be effected without shooting a bolt in the dormitory,
which in turn sets in motion an alarm. If a visitor, during
the day, should happen to knock off one from a pile of half
sovereigns the whole pile would disappear, a pool of water
taking its place.
NEW SUBSTITUTE FOR LEATHER.
Dr. George Thenius, in Vienna, has a process for the
manufacture of artificial leather from red beechwood. The
best wood for the purpose is taken from fifty to sixty years old
trees, cux :^ jtfoe /Spring, and must be worked up immediately,
bark peeled off, steamed, tr^ted &#& cbsmicaU aaa a kettle
under pressure, and then exposed to several more operations,
which the inventor does not mention, as he wants to have
them patented.
From the prepared wood strong and thin pieces are made
by means of heavy pressure. The inventor states that a solid
sole leather can be obtained, which he claims is superior t :>
the animal leather in firmness and durability, and can be
worked up in the same way as animal leather, nailed and
5ewed. We do not believe that the leather industry needs to
fear the artificial product.
THE USELESSNESS OF LIGHTNING RODS.
The uselessness of the lightning rod is becoming so gen-
erally understood that the agents find their vocation a trying
one. Fewer and fewer rods are manufactured each year, and
" the day will come when a lightning rod on a house will be
regarded in the same light as a horseshoe over a man's
THE WELLAND CANAL.
The enlarged Welland Canal is regarded as one of the
grandest exhibitions of engineering skill in the world. The
water level of Lake Erie is over 300 feet higher than that of
Lake Ontario, and this canal has been built to allow loaded
ships to pass from one lake to the other. For this passage
28 miles of canal and 26 locks are required. The small village
of Port Colborne stands at the entrance of the canal. The
first lock is built near the entrance, to keep back the swash-
ing sea, after which comes a stretch of 14 miles through a
farming country to the second lock, after which the locks are
located about as thick as possible until Lake Ontario is
reached. The greater part of the descent is in the upper
half mile of the route, and it takes about 13 hours to get
through the canal with no hindrances.
A VALUABLE POINT FOR PAPER-MAKERS.
Iron is apt to discolor paper by rusting after it has been
abraded from the paper-making machinery. Magnetism has,
therefore, been called in by a German manufacturer to clear
away the iron specks. A series of magnets are arranged in
the form of a comb and hung across the stream of pulp and
water, which, in passing the magnetic teeth of the comb,
delivers up the iron particles.
HOW TO DRIVE A^CLE THROUGH GLASS.
Iz. drilling glass, stick a piece of stiff clay or putty on the
part where you wish to make the hole. Make a hole in the
putty the size you want the hole, reaching to the glass, of
course. Into this hole pour a little molten lead, when, unless
it is very thick glass, the piece will immediately drop out.
562
THE LARGEST LOCK IN THE WORLD.
The Sault Ste. Marie canal has the second largest lock in
the world. It is built of solid masonry, 560 feet long, 80
feet wide, with walls 40 feet high, the lift 18 feet, and the
depth of I he water in the basin 1 6 feet. This lock belongs
to the United States Government and cost $3,000,000, and
will accommodate four at a time of the largest vessels ever
brought to these waters. A new and still larger lock, to
cost $5,000,000, is now being constructed. The canal now
has a larger daily traffic than the great Suez canal.
HOW GAMBOGE IS PREPARED.
Gamboge is a gum, and an average gamboge tree is said
to yield annually sufficient to fill three bamboo cylinders,
each about 18 to 20 inches long and il/2 inches in diameter.
It takes about a month to fill a cylinder. When full the
bamboo is rotated over a fire to allow the moisture to escape
and the gum to harden sufficiently to admit of being
removed.
7
A human hair is 10,000 times larger than a spider's thread.
The taxable valuation of New York city, real and per-
sonal property, for 1888, was $1,553,442,431.66.
At Erie, Pa., a well has been bored 3,500 feet. The
Schladeback boring was down to 4,515 feet.
A hammer for a pile-driver, made at Jacksonville, recently .
was the largest ever cast in Florida. It weighed 2,350
pounds.
Cavendish, in 1766, discovered hydrogen, and between
1774 and 1779 Priestley discovered oxygen, azote and nitrous
gas.
A New York dealer says that 20,000,000 pounds of rubber
comes to this country every year from Borneo, Africa, and
Para, South America.
The Chinese language is spoken by 400,000,000 persons;
Hindostani by upward of 100,000,000 ; English by more
than 100,000,000; Russian by more than 70,000,000; Ger-
man by 58,000,000; Spanish by 48,000,000, and French by
only 40,000,000.
563
COMMON NAMES OF CHEMICAL SUBSTANCES
Aqua Fortis Nitric Acid
Aqua Kegia Nitro-Muriatic Acid
mue Vitriol Sulphate of Copper
Cream of Tartar Bitartrate of Potassium
Calomel Chloride of Mercury
Chalk Carbonate of Calcium
Salt of Tartar Carbonate of Potassa
Caustic Potassa Hydrate of Potassium
Chloroform Chloride of G. ormyle
Common Salt Chloride of Sodium
Copperas or Green VitriolSulphate of Iron
Corrosive Sublimate Bichloride of Mercury
Diamond Pure Carbon
Dry Alum Sulphate Aluminum and Potassium
Epsom Salts Sulphate of Magnesia
Ethiops Mineral Black Sulphide of Mercury
Fire Damp Light Carbureted Hydrogen
Galena Sulphide of Lead
Glucose Grape Sugar
Goulard Water Basic Acetate of Lead
Iron Pyrites Bisulphide of Iron
Jeweler's Putty Oxide of Tin
King Yellow Sulphide of Arsenic
Laughing Gas Protoxide of Nitrogen
Lime Oxide of Calcium
Lunar Caustic Nitrate of Silver
Mosaic Gold Bisulphide of Tin
Muriate of Lime Chloride of Calcium
Niter of Saltpeter Nitrate of Potash
Oil of Vitriol Sulphuric Acid
Potash Oxide of Potassium
Red Lead , Oxide of Lead
Rust of Iron Oxide of Iron
Sal Ammoniac Muriate of Ammonia
Slacked Lime Hydrate of Calcium
Soda Oxide of Sodium
Spirits of Hartshorn. . . . Ammonia
Spirit of Salt Hydrochloric or Muriatic Acid
Stucco, or Plaster Paris.. Sulphate of Lime
Sugar of Lead Acetate of Lead
Verdigris Basic Acetate of Copper
Vermilion Sulphide of Mercury
Vinegar Acetic Acid (diluted
Volatile Alkali Ammonia
Water Oxide of Hydrogen
White Precipitate Ammoniated Mercury
White Vitriol Sulphate of Zinc
AN IMPROVED METHOD OF MOLDING
It is claimed that a saving, as well as a better job, can be
effected by the substitution of the following for the coal dust
and charcoal used with green sand: Take 1 part common tar
and mix with 20 of green sand ; use the same as ordinary fac-
ing. The castings are smoothed and bright, as tar prevents
metal from adhering to the sand, formation of blisters and
helps large castings by absorbing the humidity of the sand.
564
HYDRAULIC BAMS.
Very few persons understand the method of raising water
by the use of the hydraulic ram, though there are many
places on the farm where they can be profitably employed.
The invention is an old one, and apparently comes near per-
petual motion. The ram itself is a pear-shaped iron cylinder,
placed in the ground at a* depth sufficient to protect it from
the effect of frost in winter. The spring or well which sup-
lies the water is situated at some point above, so that there
will be a fall of one foot for every eight feet of perpendicu-
lar height to which the water is to be carried. For instance,
if it is necessary to force water up a hill to the house, which
stands forty-eight feet above the spring, the fall must be at
least six feet from the spring to the ram. The horizontal
distance has no effect on the calculation, and it is often car-
ried hundreds of feet, and in some cases over a thousand.
The principle on which the water is forced up is by com-
pressed air. The water passes from the spring in a pipe, say
two inches in diameter, against a check valve, which is lifted
up by the force of the water until it reaches a certain point,
when a portion of the water is crowded by its own weight
into the ram until the air is so compressed that it discharges
itself into a small pipe, say half an inch in diameter, which
runs up the elevation to the barn, house or wherever wanted.
In well constructed rams the power has been found to be
about two-thirds of the energy of the falling water.
Wherever small quantities of water are needed, this way
of supplying the want has been found to be very convenient.
The only thing that seems to stop the working is a failure of
the water supply. Night and day, year after year, the little
air engine works away, needing no rest, oil or wind, simply
water, and that in abundance. One in Norfolk county,
Massachusetts, has been in operation for many years, and is
still at work supplying the owner's house and barn with
water. To one who has never seen its workings, it is very
interesting. No visible power in sight; the little valve rises
to its proper elevation, remains there an instant, then drops
to its base of operations, only to start upward again, which
is repeated continually.
GLOSSORY OF TECHNICAL TERMS.
ABSOLUTE. Complete in itself.
Unit of Current. A current of ten ampe*res.
Unit of Electromotive Force. The one hundred mill-
ionth of a volt.
Unit of Resistance. The one thousand millionth of an
ohm.
ACCELERATION. Change in the velocity of a moving body,
either an increase or decrease, constant or variable.
ACCUMULATOR. A secondary or storage battery — a Leyden
jar
ACHROMATIC. — Without false coloration ; a lens is achromatic
when it is free from color and does not produce pris-
matic fringes in the image or object formed.
ACLINIC LINE. The line on the earth's surface connecting
those places where the magnetic needle has no incli-
nation or dip — the magnetic equator.
ACOUSTICS. That branch of natural law which treats of
sound.
ACTINISM. The property or power possessed by the sun's
rays to produce a chemical effect or decomposition (as
shown in photography).
ACTION, LOCAL. The chemical action which takes place in
a primary battery, and which consumes the zinc with-
out generating a working current.
ACTIVITY. Work done per second by any agent.
ADHESION. The force by which particles of different and
unlike bodies stick together.
AFFINITY. (Chemical). The force which combines to-
gether chemical elements to form compounds, some-
times termed " chemical attraction"
AGOUR. The line on the earth's surface of no declination
or variation of a magnetic needle.
ALLOY. A mixture or combination of two or more metallic
substances.
ALTERNATING. A motion up and down, or backward and
forward, instead of revolving.
Current. An electric current which alternately flows in
opposite directions.
AMALGAM. The combination of a metal with mercury.
AMORPHOUS. Without definite crystalline form.
566
AMPERE. The unit of strength of an electric current. The
practical unit ot an electrical current. The ampere
represents a current produced by the electromotive,
force of one volt passing through a circuit whose resist-
ance is equal to one ohm. In other words, the am-
pere represents the volume of electricity, the volt the
pressure, and the ohm the resistance encountered.
AM-METER. A device -used for measuring the strength of an
electrical current in amperes.
ANALYSIS. The process of determining the composition of
a compound substance by dividing it into the simple,
elements of which it is composed. Chemical analysis
is qualitative when it determines the kind of the simple
elements; it is qualitative when it ascertains the rela-
tive proportions of these simple elements.
ANGLE. The opening formed by two lines drawn in different
directions on a plane surface, meeting or intersecting.
ANODE. The positive pole or etectrode of a battery.
ANOMALOUS MAGNET. A magnet which has more that two
free poles.
ARC. The opening or space between two carbon points in
an electric lamp. The source of light in an electric
arc lamp.
ARMATURE. That part of a dynamo-electric machine in
which the useful currents are generated. It is the
which affects atoms, molecules and masses, so that
they will come together.
Magnetic. The mutual attraction of the opposite poles
of a magnet.
Axis. An imaginary line passing through a body, which
may be supposed to revolve around it.
Magnetic. A straight line drawn through a magnet,
joining its poles.
shaft or central revolving arm of an electric generator,
A piece of iron placed on the poles of a magnet to
preserve or keep the magnetism.
ASYMPTOTE. A curved line which, though continually ap-
proaching a straight line, never meets it.
ATMOSPHERE. The mass of air that envelopes the earth.
A pressure of a gas or fluid equal to 15 pounds per
square inch.
ATOM. The smallest quantity of simple matter which exists.
567
ATTRACTION. That force which draws together; the cause.
BALANCE, ELECTRIC. An instrument for measuring the
vahie of electrical resistance,
BARAD. The unit of electrical pressure. It is equal to one
degree per square centimetre.
BAROMETER. An instrument for measuring the pressure of
the atmosphere.
BATTERY. When applied to steam boilers it is the combina-
tion or coupling of two or more steam boilers, so as to
act as one steam source. When applied to dynamo-
electric machines it means that two or more separate
machines are combined so as to act as a single elec^
trie source. *
BATTERY, ELECTRIC. The combination, as a single source,
of two or more electrical sources. The term battery
is sometimes used to designate a single voltaic cell,
but this is incorrect. One electric battery may con-
sist of a combination of two or more Leyden jars;
two or more separate magnets; two or more primary
cells; two or more secondary or storage cells.
Bl-FiLAR. Two fibers. When used in connection with
the term suspension, it indicates that the needle or
magnet is suspended by two instead of one fiber; when
used to designate the winding of a coil (bi-filar wind-
ing of coils), it means that the coil is wound in such
a way that, instead of being wound in one continuous
length, the wire is doubled on itself, and then wound.
BINARY COMPOUND. A chemical compound formed of two
different elements. ^
BOBBIN. An insulated coil of wire — capable of rotation—,
for an electro magnet.
BRIDGE MAGNETIC. A device for measuring magnetic-resis*
tance, similar to an electric balance.
568
BROKEN CIRCUIT. An open circuit.
B. & S. An abbreviation for Brown & Sharpe's wire gauge.
B. W. G. An abbreviation for Birmingham wire gauge.
CALIBER. The inner diameter; bore.
CALORIC. A term applied to that something supposed to be
the cause of heat.
CALORIMETER. A device for measuring the quantity of
heat.
CAM. An eccentric; sometimes called camb or wiper.
CANDLE, STANDARD. A candle of a definite composition
which will produce a definite amount of light, used for
comparative measurement.
CAPILLARITY. A term used to designate the elevation of
liquids in small tubes.
CARCEL. French unit of illuminating power.
A jar containing the elements and liquid of a bat-
tery. The combination of two metals (elements) and
& liquid or liquids in such a manner as to produce a
current of electricity.
C. (J, S. SYSTEM. Cruti-meter — gramme — second system,
used to designate the absolute system of units.
CENTRIFUGAL FORCE. The force which tends to urge a
rotating or whirling body directly away from the center
of rotation.
CHAMFER. A bevel.
CIRCUIT. The path of an electric current.
CLOSURE. Completing an electrical circuit.
COIL. The arrangement of an insulated wire in symetrical
convolutions, through which an electric current can
pass.
Resistance. Coils of wire of known resistance for measur-
ing fhe resistance of any current.
569
COMMUTATOR. That part of a dynamo-electric machine
which collects the currents generated, and changes the
direction of these currents.
CONDENSER. A device for condensing a large amount of
electricity on a small surface.
CONDUCTIVITY. The ability to convey electricity; opposite
of resistance.
CONDUCTORS. Anything which will convey an electric cur-
rent.
CORE. The iron of an electro-magnet.
COULOMB. The unit of electrical quantity.
CURRENT. The flow of electricity in a conductor.
Alternating. A current which periodically reverses.
Continuous. A current which does not change its direc-
tion.
DASH-POT. A mechanical device for checking a sudden
motion, by means of a plunger working against a
cushion of air, water, or spring.
DIAPHRAGM. A thin plate or partition placed across a tube
or other hollow body; a disk ; a flat circular piece.
DIFFERENCE OF POTENTIAL. A term used to designate that
part of the electro-motive force which exists between
any two points in a circuit.
DIP, MAGNETIC- The inclination of a magnetic needle to-
ward the earth.
DYNAMO. A machm-e which furnishes electricity.
DYNAMOMETER. A device for measuring the power of an
engine or motor.
DYNE. The unit of electrical force
ECCENTRIC. Out of center; a modification of a crank; a
circular plate attached to a revolving shaft, but not
having the same center, for producing an alternat-
ing motion.
ELECTRICITY. That which is the cause of electric phenom-
enon.
ELECTRODES. Literally,, roads for electricity. The poles of
a battery. See anode and kathode.
ELECTROLYTE. A liquid which permits an electric current to
pass through it, only by means of the decomposition
of this liquid.
Electrolysis. Chemical decomposition effected by means
of an electric current.
ELECTRO-MAGNET. A magnet produced by passing a cur-
rent of electricity around a soft iron core.
E. M. F. Electro-motive force.
ELEMENT. Matter which cannot further be decomposed.
Voltaic. One of the metal or substances in a cell.
ENERGY. The power of doing work.
ERG. The unit of electrical work.
FARAD. The unit of electrical capacity.
FIELD, MAGNETIC. That space surrounding the poles of a
magnet which is within the magnetic influence.
FILAMENT. The thread of carbon in an incandescent elec-
tric lamp, which is the source of light for the lamp.
The carbon becomes luminous owing to its resistance
against the passage of the electric current through it.
Focus. The point in front or back of a lens or mirror where
the rays of light meet.
FOOT-POUND. A unit of work.
FORCE. That which produces a change in the condition ©f
rest or motion of the body.
TORMUL/E. Mathematical expressions for some general
rule or principle.
FRICTION. The resistance occasioned to the motion of
bodies by the pressure of their surface against each
other.
FULCRUM. Anything which supports a lever, or against
which a lever presses in exerting its force.
GALVANISM. A term to expres the effects of voltaic elec-
tricity.
GALVANOMETER. A device for measuring the strength of
an electrical current.
GAUSS. The unit of intensity of a magnetic field.
GRAVITY. The force which causes masses c*f matter to tend
to move toward each other.
HELICES. Coils of wire which acquire all the properties of
a magnet when traversed by an electrical current.
HYDRODYNAMICS. That branch of general mechanics which
treats of the equilibrium and motion of fluids.
HYDROSTATICS. Same as hydrodynamics.
572
IMPACT. The effect of a blow or stroke from one source to
another, whether in motion or at rest.
IMPETUS. Effect produced by the velocity of a moving body.
IMPONDERABLE. Possessing no weight.
INCANDESCENSE, ELECTRICAL. The electric heating of a
solid to luminosity.
INERTIA. That property of matter which tends to cause
matter when at rest to remain so.
JACK ARCH. An arch the thickness of one brick.
JACK-SCREW. A lifting instrument which acts by the rota-
tion of a screw in a threaded socket.
JAG. A dovetail or barb.
JAG-BOLT. One with a barbed shank.
JAMB. The upright sides of a doorway, frame, window or
fire-place.
JAM-NUT. A check-nut, a lock-nut. One nut screwed down
upon another nut to hold it.
JOURNAL. That part of an axle or shaft which rests on the
bea-ings.
JOULE. The unit of heat — electrical
KATHCBR. The negative pole or electrode of a battery.
KEY. A wedge piece of iron or steel for holding
pulleys in place.
573
. A slot in the centers of pulleys or on a shaft, for
the reception of a key, which holds the pulley or wheel
in place.
KINETIC ENERGY. Is the work a body can do in virtue of
its motion.
LAP. Is the space which the slide valve advances, on the
steam side, beyond the opening of the steam port after
it has closed it, and is given for the purpose of causing
the engine to work expansively by cutting off the
admission of steam before the end of the stroke.
LAP-WELD. A weld in which the welding edges are thinned
down, lapped and welded.
LEAD. An arrangement of the ports of a steam-valve by
which steam is admitted in front of the piston a little
before the end of the piston stroke; also an arrange-
ment of the ports to provide for the escape of the
steam from behind the piston before the completion of
the stroke. When on the steam side it is called outside
lead, when on the exhaust side it is inside lead.
LENS. A piece of transparent substance (usually glass)
fashioned into a shape affording two regular opposite
surfaces, both curved, or one curved, and the other
plane, by which the direction of rays of light are
changed, diminishing or increasing the apparent size of
objects viewed through them.
LEVER. A bar or other rigid device having a fixed point, or
fulcrum, in the use of which an increase of power,
speed or facility is gained in lifting or other exercise
of power. When the fulcrum is between the weight
and power, the lever is* of the first class; when the
fulcrum is opposite the power, the lever is of the
second class; when the fulcrum is opposite the weight,
the lever is of the third class.
574
LINK MOTION. A gear by which the steam-valve of a loco-
motive or engine is operated, so that a reversible
motion may be secured.
LIVE STEAM. Steam direct from the boiler at full nressure.
MAGNET. A body possessing the power of attracting iron,
steel, etc.
Electro. A magnet produced by the passage of a cur-
rent of electricity around a core of soft iron.
MALLEABLE. Capable of being hammered out into thin
plates.
MASS, The quantity of matter contained in a body.
MATTER. That which occupies space, and prevents other
matter from occupying the same space at the same
time. Matter is composed of atoms, which unite to
form molecules.
MOLECULE. The smallest portion of matter capable of being
divided. •
MOMENTUM. Is the rate of change of velocity— and may be
either positive or negative.
MOVER-PRIME. The initial motor, or that which drives
secondary movers.
NEGATIVE. Opposite to positive. One of the phases
(not k'nds) or states of electrical excitement.
NON-CONDUCTORS. Insulators. Substances which offer
considerable resistance to the passage of electricity.
575
OHM. The unit of electrical resistance.
©HMMETER. A device for measuring electrical resistance.
OPTICS. That branch of natural science which treats of the
eye or vision.
ORIFICE. An opening; aperture.
OSMOSE. The unequal mixing of fluids of different densities
through the pores of a separating medium.
PARAMAGNETIC. Substances possessing magnetic qualities.
POSITIVE. Opposite to negative. One of the phases (not
kinds) or states of electrical excitement.
POTENTIAL. The power of doing electrical work. Electric
level.
POWER. Rate of doing work.
FADIATION. The transference of energy by means of ether
waves.
R ECIPROCALS. The quotient arising from dividing unites by
any number.
R fcsuLTANT. A force which represents the effect of two or
more forces acting in different directions.
576
SHUNT. A branch or additional current provided at any part
of a circuit; a short circuit.
SOLENOID. A cylindrical coil of wire, each convolution of
which is a circle, and which acquires all the properties
of a magnet when traversed by an electrical current.
TENACITY, The quality of holding fast.
TENSE. Strained tight; taut.
TENSION. Act or degree of stretching; elastic power.
TERTIARY. Third, of the third formation or power.
TORSION. Act of twisting; state of twist.
VACUUM. A space from which all air or gas has been
removed.
VELOCITY. The rate of motion. It involves the idea of
direction as well a§ magnitude. It is uniform when
the rate of motion does not change.
VIBRATION. A to and fro motion.
VOLT. The practical unit of electromotive force.
WATT. The volt-ampere or unit of electrical work.
WORK. That which is done by a force. It is the product of
the force and the distance through which it acts.
UNIVERSITY OF CALIFORNIA
BRANCH OF THE COLLEGE OF AGRICULTURE
THIS BOOK IS DUE ON THE LAST BATE
STAMPED BELOW
9353
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2dison. 'T.
£?.
1895
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anics1 comple
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