CONTENTS

PAGE
LIST OF ILLUSTRATIONS[xiii]
ACKNOWLEDGMENTS[xxi]
CHAPTER
I.INTRODUCTORY[1]
II.FORM
Form as important as substance. Why a joist is stiffer than a plank. The girder isdeveloped from a joist. Railroad rails are girders of great efficiency as designed and tested by Mr. P. H. Dudley
[5]
III.FORM CONTINUED. BRIDGES
Roofs and small bridges may be built much alike. The queen-posttruss, adapted for bridges in the sixteenth century, neglected for two hundred years and more. A truss replaces the Victoria TubularBridge. Cantilever spans at Niagara and Quebec. Suspension bridges at New York. The bowstring design is an arch disguised. Why bridges arebuilt with a slight upward curve. How bridges are fastened together in America and in England
[18]
IV.FORM CONTINUED. LIGHTNESS, EASE IN MOTION
Why supports are made hollow. Advantages of thearch in buildings, bridges and dams. Tubes in manifold new services. Wheels more important than ever. Angles give way to curves
[39]
V.FORM CONTINUED. SHIPS
Ships have their resistances separately studied. This leads toimprovements of form either for speed or for carrying capacity. Experiments with models in basins. The Viking ship, a thousand years old,of admirable design. Clipper ships and modern steamers. Judgment in design
[52]
VI.FORM CONTINUED. RESISTANCE LESSENED
Shapes to lessen resistance to motion. Shot formed tomove swiftly through the air. Railroad trains and automobiles of somewhat similar shape. Toothed wheels, conveyors, propellers andturbines all so curved as to move with utmost freedom
[65]
VII.FORM CONTINUED. ECONOMY OF LIGHT AND HEAT
Light economized by rightly-shaped glass. Heatsaved by well-designed conveyors and radiators. Why rough glass may be better than smooth. Light is directed in useful paths by prisms.The magic of total reflection is turned to account. Holophane Globes. Prisms in binocular glasses. Lens grinding. Radiation of heatpromoted or prevented at will
[72]
VIII.FORM CONTINUED. TOOLS AND IMPLEMENTS
Tools and implements shaped for efficiency. Edge toolsold and new. Cutting a ring is easier than cutting away a whole circle. Lathes, planers, shapers, and milling machines far out-speed thehand. Abrasive wheels and presses supersede old methods. Use creates beauty. Convenience in use. Ingenuity spurred by poverty inresources
[89]
IX.FORM CONTINUED. ABORIGINAL ART
Form in aboriginal art, as affected by materials. Old formspersist in new materials. Nature’s gifts first used as given, then modified and copied. Rigid materials mean stiff patterns. Newmaterials have not yet had their full effect on modern design
[108]
X.SIZE
Heavenly bodies large and small. The earth as sculptured a little at a time. Thefarmer as a divider. Dust and its dangers. Models may mislead. Big structures economical. Smallness of atoms. Advantages thereof. Dustrepelled by light
[120]
XI.PROPERTIES
Food nourishes. Weapons and tools are strong and lasting. Clothing adorns andprotects. Shelter must be durable. Properties modified by art. High utility of the bamboo. Basketry finds much to use. Aluminium, howproduced and used. Qualities long unwelcome or worthless are now gainful. Properties created at need
[135]
XII.PROPERTIES CONTINUED
Producing more and better light from both gas and electricity. TheDrummond light. The Welsbach mantle. Many rivals of carbon filaments and pencils. Flaming arcs. Tubes of mercury vapor
[154]
XIII.PROPERTIES CONTINUED
Steel: its new varieties are virtually new metals, strong, tough, andheat resisting in degrees priceless to the arts. Minute admixtures in other alloys are most potent
[163]
XIV.PROPERTIES CONTINUED
Glass of new and most useful qualities. Metals plastic under pressure.Non-conductors of heat. Norwegian cooking box. Aladdin oven. Matter seems to remember. Feeble influences become strong in time
[180]
XV.PROPERTIES CONTINUED. RADIO-ACTIVITY
Properties most evident are studied first. Then thosehidden from cursory view. Radio-activity revealed by the electrician. A property which may be universal, and of the highest import. Itsstudy brings us near to ultimate explanations. Faraday’s prophetic views
[197]
XVI.MEASUREMENT
Methods beginning in rule-of-thumb proceed to the utmost refinement. Standardsold and new. The foot and cubit. The metric system. Refined measurement as a means of discovery. The interferometer measures15,000,000inch. A light-wave as an unvarying unit of length
[208]
XVII.MEASUREMENT CONTINUED
Weight, Time, Heat, Light, Electricity, measured with new precision.Exact measurement means interchangeable designs, and points the way to utmost economies. The Bureau of Standards at Washington. Measurementin expert planning and reform
[219]
XVIII.NATURE AS TEACHER
Forces take paths of least resistance. Accessibility decides where citiesshall arise. Plants display engineering principles in structure. Lessons from the human heart, eyes, bones, muscles, and nerves. Whatnature has done, art may imitate,—in the separation of oxygen from air, in flight, in producing light, in converting heat into work:Lessons from lower animals. A hammer-using wasp
[245]
XIX.QUALIFICATIONS OF INVENTORS AND DISCOVERERS
Knowledge as sought by disinterested inquirers.A plenteous harvest with few reapers. Germany leads in original research. The Carnegie Institution at Washington
[267]
XX.OBSERVATION
What to look for. The eye may not see what it does not expect to see. Lensesreveal worlds great and small otherwise unseen. Observers of the heavens and of seashore life. Collections aid discovery. Happy accidentsapplied to profit. Popular beliefs may be based on truth. An engineer taught by a bank swallow
[279]
XXI.EXPERIMENT
Newton, Watt, Ericsson, Rowland, as boys were constructive. The passion formaking new things. Aid from imagination and trained dexterity. Edison tells how the phonograph was born. Telephonic messages recorded.Handwriting transmitted by electricity. How machines imitate hands. Originality in attack
[299]
XXII.AUTOMATICITY AND INITIATION
Self-acting devices abridge labor. Trigger effects in thelaboratory, the studio and the workshop. Automatic telephones. Equilibrium of the atmosphere may be easily upset
[329]
XXIII.SIMPLIFICATION
Simplicity always desirable, except when it costs too dear. Taking directinstead of roundabout paths. Omissions may be gainful. Classification and signaling simpler than ever before
[340]
XXIV.THEORIES HOW REACHED AND USED
Educated guessing. Weaving power. Imagination indispensable.The proving process. Theory gainfully directs both observation and experiment. Tyndall’s views. Discursiveness of ThomasYoung
[355]
XXV.THEORIZING CONTINUED
Analogies have value. Many principles may be reversed with profit. Thecontrary of an old method may be gainful. Judgment gives place to measurement, and then passes to new fields
[366]
XXVI.NEWTON, FARADAY AND BELL AT WORK
Newton, the supreme generalizer. Faraday, the master ofexperiment. Bell, the inventor of the telephone, transmits speech by a beam of light
[387]
XXVII.BESSEMER, CREATOR OF CHEAP STEEL. NOBEL, INVENTOR OF NEW EXPLOSIVES
Bessemer a man ofgolden ignorances. His boldness and versatility. The story of his steel process told by himself. Nobel’s heroic courage in failureand adversity. His triumph at last. Turns an accidental hint to great profit. Inventors to-day organized for attacks of new breadth andaudacity
[401]
XXVIII.COMPRESSED AIR
An aid to the miner, quarryman and sculptor. An actuator for pumps. Engravesglass and cleans castings. Dust and dirt removed by air exhaustion. Westinghouse air-brakes and signals
[417]
XXIX.CONCRETE AND ITS REINFORCEMENT
Pouring and ramming are easier and cheaper than cutting andcarving. Concrete for dwellings ensures comfort and safety from fire. Strengthened with steel it builds warehouses, factories and bridgesof new excellence
[429]
XXX.MOTIVE POWERS PRODUCED WITH NEW ECONOMY
Improvements in steam practice. Mechanical draft.Automatic stokers. Better boilers. Superheaters. Economical condensers. Steam turbines on land and sea
[446]
XXXI.MOTIVE POWERS, CONTINUED. HEATING SERVICES
Producer gas. Mond gas. Gas engines. Steam andgas engines compared. Diesel engine best heat motor of all. Gasoline motors. Alcohol engines. Steam and gas motors united. Heat and powerproduction together. District steam heating. Isolated plants. Electric traction. Gas for a service of heat, light and power
[457]
XXXII.A FEW SOCIAL ASPECTS OF INVENTION
Why cities gain at the expense of the country. Thefactory system. Small shops multiplied. Subdivided labor has passed due bounds and is being modified. Tendencies against centralizationand monopoly. Dwellings united for new services. Self-contained houses warmed from a center. The literature of invention and discovery aspurveyed in public libraries
[478]
INDEX[489]

LIST OF ILLUSTRATIONS

[Professor Alexander Graham Bell]Frontispiece
[Bell Homestead, Brantford, Ontario]facing 2
[Lens of ice focussing a sunbeam]5
[Rubber strip suspended plank-wise and joist-wise]7
[Board doubled breadthwise and edgewise]7
[Telegraph poles under compression. Wires under tension]8
[Rubber cylinder, flattened by compression, lengthened by tension]9
[Rubber joist compressed along top, extended along bottom]10
[Girder cut from joist]10
[Rubber I-beam suspended flatwise and edgewise]10
[Girder contours simple, built up, in locomotive draw-bars]11
[Steel ore car]12
[Bulb angle column, New York Subway]12
[Strap rail and stringer, Mohawk & Hudson R. R., 1830]13
[Plimmon H. Dudley]facing 14
[Dudley rails]16
[Steel cross-ties and rails]17
[King-post truss]18
[Frames of four sides]19
[Cross-section Arctic ship “Roosevelt”]20
[Pair of compasses stretch a rubber strip]20
[Queen-post truss]21
[Upper part of roof truss, Interborough Power House, New York]21
[Two queen-post trusses from a bridge]22
[Palladio trusses]22
[Burr Bridge, Waterford, N. Y.]23
[Howe and Pratt trusses]24
[Baltimore truss]25
[Whipple Bridge]25
[Simple cantilevers]26
[Victoria Bridge, Montreal, original form]27
[Victoria Bridge, Montreal, present form]28
[Cantilever Bridge, near Quebec]29
[Kentucky River Cantilever Bridge]30
[Arch Bridge, Niagara Falls]31
[Bowstring Bridge, Philadelphia]32
[Williamsburg Bridge, New York City]33
[Continuous Girder Bridge, Lachine, near Montreal]34
[Rubber strip supported at 4 points, and at 2 points]34
[Plate girder bridge]35
[Lattice girder bridge, showing rivets]36
[Bookshelf laden and unladen, showing camber]36
[Pin connecting parts of bridge]37
[Bridge rollers in section and in plan]38
[Girder sections in various forms]39
[Rubber cylinders solid and hollow compared in sag]40
[Handle bar of bicycle in steel tubing]40
[A sulky in steel tubing]41
[Pneumatic hammer in steel tubing]41
[Fishing rod in steel tubing]41
[Bridge of steel pipe]41
[Arch bridge of steel pipe]42
[Spiral fire-lighter]42
[Spiral weld steel tube]42
[Largest stone arch in the world, Plauen, Germany]43
[Church of St. Remy, Rheims, France]43
[Curve of suspended chain]44
[Dam across Bear Valley, California]44
[Ferguson locking-bar]45
[Hand-hole plates, Erie City water-tube boiler]46
[Bullock cart with solid wheels]47
[Ball thrust collar bearings]48
[Rigid bearings for axles of automobiles]48
[Hyatt helical roller bearing. Ditto supporting an axle]49
[Treads and risers of stairs joined by curves]49
[Corner Madison Square Garden, New York]50
[Two pipes with funnel-shaped junction] 50
[Model Basin, U. S. Navy, Washington, D. C.]facing 54
[Viking Ship]56
[Clipper ship “Young America”]58
[Steamship Kaiser Wilhelm II]60
[Cargo steamer]61
[U. S. Torpedo-boat destroyer]62
[Cross-sections of ships]63
[Racing automobile. Wedge front and spokeless wheels]66
[Bilgram skew gearing]67
[Grain elevator]68
[Robins conveying belt]68
[Ewart detachable link belting]69
[Curves of turbines]70
[Steel vanes of windmill]70
[Pelton water wheel and jet]71
[Luxfer prism]74
[Fresnel lens]74
[Lamp and reflector a unit]75
[Inverted arc-light]75
[Sacramento perch totally reflected in aquarium]77
[Diagram illustrating total reflection]78
[Holophane globe, sections]79
[Holophane globe, diffusing curves]80
[Holophane globe, three varieties]80
[Holophane globe, and Welsbach mantle]81
[Wire shortened while original direction is resumed]81
[Four mirrors reflect a ray in a line parallel to first path]82
[Prisms for Zeiss binocular glasses]82
[Sections for Zeiss binocular glasses]83
[Tools for producing optical surfaces]84
[Bi-focal lens for spectacles]85
[Canadian box-stove]86
[Canadian dumb-stove]86
[Tubing for radiator]87
[Gold’s electric heater]87
[Stolp wired tube for automobiles]87
[Corrugated boiler]88
[Pipe allowing contraction or expansion] 88
[Carving chisels and gouges]90
[Lathe cutters]90
[Ratchet bit brace]90
[Eskimo skin scraper]91
[Double tool drill cutting boiler plate]91
[Common drill compared with ring drill]92
[Twist drill]93
[How a tool cuts metal]94
[Dacotah fire-drill]94
[Lathe, with parts in detail]95
[Compound slide rest]96
[Blanchard lathe]96
[Turret lathe, with side and top views]97
[Ericsson’s Monitor]98
[Iron planer]99
[Iron shaper]99
[Milling machine]100
[Milling cutters with inserted teeth]100
[Milling cutters executing curves]101
[Emery wheels]102
[Carborundum wheel edges]102
[Rolls to reduce steel in thickness]104
[Gourd-shaded vessel, Arkansas]108
[Gourd and derived pottery forms]109
[Pomo basket]109
[Bilhoola basket]110
[Bilhoola basket, a square inch of]111
[A free-hand scroll: same as woven]111
[Yokut basket bowl]112
[Sampler on cardboard]115
[Bark vessel and derived form in clay]115
[Vase from tumulus, St. George, Utah]116
[Wooden tray. Clay derivative]116
[Shell vessel. Earthen derivative]116
[Electric lamps in candle shapes]117
[Notre Dame de Bonsecours, Montreal]118
[New Amsterdam Theater, New York]facing 118
[Cinders large and small on hearth] 120
[Cube subdivided into 8 cubes]121
[Cube built of 27 cubes]122
[Two rubber strips, varying as one and three in dimensions, compared in sag]127
[Air bubbles rising in oil]128
[Dvorak sound-mill]132
[Beam of light deflects dust]133
[Dr. Carl Freiherr Auer von Welsbach]facing 156
[Boivin burner for alcohol]157
[Alcohol lamp with ventilating hood]158
[Welsbach mantle]159
[Tantalum lamp]160
[Tungsten lamp of Dr Kuzel]160
[Hewitt mercury-vapor lamp]161
[Sections Pearlite and Steel]facing 164
[Cleaning Cars by the “Vacuum” Method]facing 164
[Open hearth furnace]165
[Professor Ernst Abbe]facing 182
[Bliss forming die]184
[Bliss process of shell making]184
[Mandolin pressed in aluminium]185
[Pressed seamless pitcher]185
[Barrel of pressed steel]185
[Range front of pressed steel]186
[Pressed paint tube and cover]186
[Norwegian cooker]189
[Aladdin oven]190
[Mayer’s floating magnets]193
[Alum crystal, broken and restored]194
[Marble before and after deformation by pressure]195
[Professor Ernest Rutherford]facing 202
[Professor A. A. Michelson]facing 214
[Michelson interferometer]215
[Light-wave distorted by heated air]216
[Ancient Egyptian balance]219
[Rueprecht balance]220
[Earnshaw compensated balance wheel]223
[Riefler clock]224
[Photometer]227
[Compass needle deflected by electric wire]230
[Compass needle deflected by electric coil]231
[Maxwell galvanometer]231
[Weston voltmeter]232
[Micrometer caliper measuring 11000 inch]236
[Plug and ring for standard measurements]237
[Two lenses as pressed together by Newton]237
[Newton’s rings]238
[Flat jig or guide]239
[Deciduous cypress]247
[Deciduous cypress, hypothetical diagram]248
[Section of pipe or moor grass; of bulrush]251
[Human hip joint]252
[Valves of veins]252
[Built-up gun]253
[Achromatic prisms and lens]255
[Three levers]256
[Arm holding ball]256
[Beaver teeth]258
[Narwhal with twisted tusk]259
[Lower part of warrior ants’ nest, showing dome]260
[Wasp using pebble as hammer]260
[Cuban firefly]263
[Dr. R. S. Woodward]facing 276
[Perforated sails for ships]292
[Edison phonograph]312
[Telegraphone]314 and
facing
314
[Gray Telautograph]315 and
facing
318
[Hussey’s mower or reaper]321
[Mergenthaler linotype, justifying wedges]323
[Schuckers’ double-wedge justifier]324
[Two wedges partly in contact, and fully in contact]325
[Polarized light shows strains in glass]327
[Stop-motion]330
[Dexter feeding mechanism]331
[Schumann’s “Traumerei” in musical score and on Pianola roll]334
[Mechanism of Pianola]335
[Automatic Telephone]336 and
facing
336
[Blenkinsop’s locomotive, 1811]345
[Notes on loose cards in alphabetical order]350
[Sectional bookcase, desk and drawers]351
[Burke telegraphic code]353
[Burke simplified telegraphic signals]354
[Pupin long-distance telephony]367
[Water-gauge direct and reversed]370
[Thomas Alva Edison]facing 374
[Cube-root extractor]376
[Square-root extractor]377
[Sturtevant ventilating and heating apparatus]380
[Bicycle suspended from axle]382
[Telephones receiving sound through a beam of light]395
[Selenium cylinder with reflector]398
[Perforated disc yielding sound from light]399
[Sir Henry Bessemer]facing 402
[First Bessemer converter and ladle]406
[New Ingersoll coal cutter]418
[Drill steels]418
[Sculptor at work with Pneumatic Chisel]facing 418
[Haeseler air-hammer]419
[Rock drill used as hammer]420
[Little Giant wood-boring machine]420
[Water lifted by compressed air]421
[Harris system of pumping by compressed air]422
[Hardie nozzle for painting by compressed air]423
[Vacuum renovators for carpets and upholstery]424
[Injector sand-blast, Drucklieb’s]425
[Vertical receiver, inter- and outer-cooler]426
[Concrete silo foundation]431
[Concrete silo]432
[Mansion in Concrete, Fort Thomas, Kentucky]facing 432
[Wall of two-piece concrete blocks]434
[Ransome bar for concrete]436
[Corrugated steel bar]436
[Thacher bar]436
[Kahn bar]437
[Hennebique armored concrete girder]437
[Monier netting]437
[Expanded metal diamond lath]438
[Tree box in expanded steel]438
[Royal Bank of Canada, Havana]facing 438
[Lock-woven wire fabric]439
[Column forms for concrete, Ingalls Building, Cincinnati]440
[Section of chimney, Los Angeles, Cal.]441
[Coignet netting and hook]442
[Section of conduit, Newark, N. J.]442
[Water culvert]443
[River des Pêres Bridge, Forest Park, St. Louis]444
[Memorial Bridge, Washington, D. C.]444
[Francis vertical turbine wheel]446
[5000 Horse-Power Allis-Chalmers Steam Engine]facing 448
[Smoke-jack]449
[Power House, Interborough Co., New York, exterior]facing 450
[Schmidt superheater]451
[Power House, Interborough Co., New York, interior]facing 452
[De Laval steam turbine, sections]453
[Westinghouse-Parsons Steam Turbine]facing 454
[Combustible gas from a candle]458
[Taylor gas-producer]460
[Four-cycle gas engine]463
[Fire syringe]467
[Sturtevant fan wheel, without casing]472
[Sturtevant Monogram exhauster and solid base heater]473
[New York Central R. R. Electric Locomotive with Five-Car Train]facing 476