| [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 1⁄1000 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 |