Copyright
George Iles.

Inventors at work, with chapters on discovery online

. (page 1 of 41)
Online LibraryGeorge IlesInventors at work, with chapters on discovery → online text (page 1 of 41)
Font size
QR-code for this ebook


INVENTORS




UNIVERSITY OF CALIFORNIA LIBRARY




Copyright by Park & Co., Brantford, Ontario.

PROFESSOR ALEXANDER GRAHAM BELL.



Inventors at Work

With Chapters on Discovery



By George lies

Author of " Flame, Electricity and the Camcn



Copiously Illustrated




or THE
UNIVERSITY




New York
Doubleday, Page & Company

1906



Copyright, 1906, by
GEORGE ILES

Published October, 1906

All rights reserved, including that
of translation into foreign Ian-
guages, including the Scandinavian



iv



TO MY FRIEND

JOSEPHUS NELSON LARNED

OF BUFFALO, NEW YORK



CONTENTS

PACT

LIST OF ILLUSTRATIONS xiii

ACKNOWLEDGMENTS xxi

CHAPTER

I. INTRODUCTORY I

II. FORM

Form as important as substance. Why a joist is stiffer
than a plank. The girder is developed from a joist. Rail-
road 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-post truss, adapted for bridges in the sixteenth cen-
tury, neglected for two hundred years and more. A truss
replaces the Victoria Tubular Bridge. Cantilever spans at
Niagara and Quebec. Suspension bridges at New York.
The bowstring design is an arch disguised. Why bridges
are built 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 the arch
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
to improvements 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 . . . . 5 2
vii



viii CONTENTS

VI. FORM CONTINUED. RESISTANCE LESSENED
Shapes to lessen resistance to motion. Shot formed to move
swiftly through the air. Railroad trains and automobiles
of somewhat similar shape. Toothed wheels, conveyors,
propellers and turbines all so curved as to move with ut-
most freedom 65

VII. FORM CONTINUED. ECONOMY OF LIGHT AND

HEAT

Light economized by rightly-shaped glass. Heat saved 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 heat promoted or prevented
at will 72

VIII. FORM CONTINUED. TOOLS AND IMPLEMENTS
Tools and implements shaped for efficiency. Edge tools old
and new. Cutting a ring is easier than cutting away a
whole circle. Lathes, planers, shapers, and milling ma-
chines far out-speed the hand. Abrasive wheels and presses
supersede old methods. Use creates beauty. Convenience
in use. Ingenuity spurred by poverty in resources ... 89

IX. FORM CONTINUED. ABORIGINAL ART

Form in aboriginal art, as affected by materials. Old forms
persist in new materials. Nature's gifts first used as given,
then modified and copied. Rigid materials mean stiff pat-
terns. New materials 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. The farmer as a divider. Dust and
its dangers. Models may mislead. Big structures econom-
ical. Smallness of atoms. Advantages thereof. Dust re-
pelled by light . 120

XI. PROPERTIES

Food nourishes. Weapons and tools are strong and lasting.
Clothing adorns and protects. Shelter must be duraHe.
Properties modified by art. High utility of the bamboo.
Basketry finds much to use. Aluminium, how produced and
used. Qualities long unwelcome or worthless are now gain-
ful. Properties created at need 135



CONTENTS



IX



XIT. PROPERTIES CONTINUED

Producing more and better light from both gas and elec-
tricity. The Drummond 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, and heat 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 un-
der 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 those hid-
den from cursory view. Radio-activity revealed by the elec-
trician. A property which may be universal, and of the
highest import. Its study brings us near to ultimate ex-
planations. Faraday's prophetic views 197

XVI. MEASUREMENT

Methods beginning in rule-of-thumb proceed to the utmost
refinement. Standards old and new. The foot and cubit.
The metric system. Refined measurement as a means of
discovery. The interferometer measures .^1^ inch. 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 de-
signs, and points the way to utmost economies. The Bureau
of Standards at Washington. Measurement in expert plan-
ning and reform 219

XVIII. NATURE AS TEACHER

Forces take paths of least resistance. Accessibility decides
where cities shall arise. Plants display engineering prin-
ciples in structure. Lessons from the human heart, eyes,
bones, muscles, and nerves. What nature 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



x CONTENTS

XIX. QUALIFICATIONS OF INVENTORS AND DISCOV-
ERERS

Knowledge as sought by disinterested inquirers. A plente-
ous 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. Lenses reveal worlds great and small other-
wise unseen. Observers of the heavens and of seashore life.
Collections aid discovery. Happy accidents applied 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 construc-
tive. The passion for making new things. Aid from imag-
ination and trained dexterity. Edison tells how the phono-
graph was born. Telephonic messages recorded. Hand-
writing transmitted by electricity. How machines imitate
hands. Originality in attack 299

XXII. AUTOMATICITY AND INITIATION

Self-acting devices abridge labor. Trigger effects in the
laboratory, the studio and the workshop. Automatic tele-
phones. Equilibrium of the atmosphere may be easily up-
set 329

XXIII. SIMPLIFICATION

Simplicity always desirable, except when it costs too dear.
Taking direct instead 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 indis-
pensable. The proving process. Theory gainfully directs
both observation and experiment. Tyndall's views. Dis-
cursiveness of Thomas Young 355

XXV. THEORIZING CONTINUED

Analogies have value. Many principles may be reversed
with profit. The contrary of an old method may be gain-
ful. Judgment gives place to measurement, and then passes
to new fields 366



CONTENTS xi

XXVI. NEWTON, FARADAY AND BELL AT WORK

Newton, the supreme generalizer. Faraday, the master of
experiment. Bell, the inventor of the telephone, transmits
oeech by a beam of light 387



XXVII. BESSEMER, CREATOR OF CHEAP STEEL. NOBEL,

INVENTOR OF NEW EXPLOSIVES
Bessemer a man of golden ignorances. His boldness and
versatility. The story of his steel process told by himself.
Nobel's heroic courage in failure and adversity. His tri-
umph at last. Turns an accidental hint to great profit. In-
ventors to-day organized for attacks of new breadth and
audacity 401



XXVIII. COMPRESSED AIR

An aid to the miner, quarryman and sculptor. An actu-
ator for pumps. Engraves glass 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
and carving. Concrete for dwellings ensures comfort and
safety from fire. Strengthened with steel it builds ware-
houses, factories and bridges of new excellence .... 429



XXX. MOTIVE POWERS PRODUCED WITH NEW

ECONOMY

Improvements in steam practice. Mechanical draft Auto-
matic stokers. Better boilers. Superheaters. Economical
condensers. Steam turbines on land and sea 446



XXXI. MOTIVE POWERS, CONTINUED. HEATING SER-
VICES

Producer gas. Mond gas. Gas engines. Steam and gas
engines compared. Diesel engine best heat motor of all.
Gasoline motors. Alcohol engines. Steam and gas motors
united. Heat and power production together. District
steam heating. Isolated plants. Electric traction. Gas for
a service of heat, light and power 457



xii CONTENTS

XXXII. A FEW SOCIAL ASPECTS OF INVENTION

Why cities gain at the expense of the country. The factory
system. Small shops multiplied. Subdivided labor has
passed due bounds and is being modified. Tendencies
against centralization and monopoly. Dwellings united for
new services. Self-contained houses warmed from a
center. The literature of invention and discovery as pur-
veyed 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 ... 1 1

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



xiv LIST OF ILLUSTRATIONS

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



LIST OF ILLUSTRATIONS xv

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 81

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



xvi LIST OF ILLUSTRATIONS

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-shaped vessel, Arkansas 108

Gourd and derived pottery forms 109

Pomo basket 109

Bilhoola basket no

Bilhoola basket, a square inch of 1 1 1

A free-hand scroll : same as woven in

Yokut basket bowl 112

Sampler on cardboard 115

Bark vessel and derived form in clay 115

Vase from tumulus, St. George, Utah 1 16

Wooden tray. Clay derivative 1 16

Shell vessel. Earthen derivative 116

Electric lamps in candle shapes 117

Notre Dame de Bonsecours, Montreal 118

NEW AMSTERDAM THEATER, NEW YORK. facing 118



LIST OF ILLUSTRATIONS xvii

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 I3 2

Beam of light deflects dust 133

DR. CARL FREIHERR AUER vox WELSBACII 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 STEEI 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



xviii LIST OF ILLUSTRATIONS

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 i/iooo 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



LIST OF ILLUSTRATIONS xix

Mechanism of Pianola 335

AUTOMATIC TELEPHONE 336 and facing 336

Blenkinsop's locomotive, 181 1 345

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



xx LIST OF ILLUSTRATIONS

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 Peres Bridge, Forest Park, St. Louis 444

Memorial Bridge, Washington, D. C 444

Francis vertical turbine wheel 446

5000 HORSE- POWER ALLIS-CHALJMERS STEAM ENGINE, facing 448

Smoke-jack 449

POWER HOUSE, INTERBOROUGH Co., NEW YORK, ex-
terior facing 450

Schmidt superheater 451

POWER HOUSE, INTERBOROUGH Co., NEW YORK, in-
terior 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



ACKNOWLEDGMENTS

AID in writing this volume is acknowledged in the course of its
chapters. The author's grateful thanks are rendered also to
Dr. L. A. Fischer, of the Bureau of Standards at Washington,
who has revised the paragraphs describing the work of the
Bureau ; to Mr. C. R. Mann of the Ryerson Physical Laboratory,
University of Chicago, who corrected the paragraphs on the inter-
ferometer; to Mr. Walter A. Mitchell, formerly of Columbia
University, New York, who revised most of the chapters on
measurement. Mr. Thomas E. Fant, Head of the Department
of Construction and Repair at the Navy Yard, Washington, D. C.,
gave the picture of the model basin here reproduced. Mr. Walter
Hough of the National Museum, Washington*, D. C., contributed
a photograph of the Pomo basket also reproduced here. Mr. John
Van Vleck and Mr. Henry G. Stott of New York, Mr. George R.
Prowse and Mr. Edson L. Pease of Montreal, have furnished
drawings and photographs for illustrations of unusual interest.
Mr. George F. C. Smillie, of the Bureau of Engraving, Washing-
ton, D. C., Mr. Percival E. Fansler, Mr. Ernest Ingersoll, and
Mr. Ashley P. Peck, of New York, have read in proof parts of
the chapters which follow. Their corrections and suggestions
have been indispensable.

Professor Bradley Stoughton, of the School of Mines, Colum-
bia University, New York, has been good enough to contribute a
brief list of books on steel, supplementing the chapter on that
theme written with his revision. Had it been feasible, other chap-
ters would have been supplemented in like manner by other
teachers of mark. In 1902 the American Library Association
published an annotated guide to the literature of American his-
tory, engaging forty critics and scholars of distinction, with Mr.

xxi



xxii ACKNOWLEDGMENTS

J. N. Larned as editor. It is hoped that at no distant day guides
on the same helpful plan will be issued in the field of science, duly
supplemented and revised from time to time.

In the present volume the author has endeavored to include in
his survey the main facts to the close of May, 1906.

NEW YORK, September, 1906.



INVENTORS AT WORK



rr -HE
L

OF



CHAPTER I
INTRODUCTORY

INVENTORS and discoverers are justly among the most
JL honored of men. It is they who add to knowledge, who
bring matter under subjection both in form and substance, who
teach us how to perform an old task, as lighting, with new econ-
omy, or hand us gifts wholly new, as the spectroscope and the
wireless telegraph. It is they who tell us how to shape an oar
into a rudder, and direct a task with our brains instead of tugging
at it with our muscles. They enable us to replace loss with gain,
waste with thrift, weariness with comfort, hazard with safety.
And, chief service of all, they bring us to understand more and
more of that involved drama of which this planet is by turns the
stage and the spectator's gallery. The main difference between
humanity to-day and its lowly ancestry of the tree-top and the
cave has been worked out by the inventors and discoverers who
have steadily lifted the plane of life, made it broader and better
with every passing year.

On a theme so vast as the labors of these men a threshold book
can offer but a few glances at principles of moment, to which
the reader may add as he pleases from observations and ex-
periments of his own. At the outset Form will engage our
regard : first, as bestowed so as to be retained by girders, trusses
and bridges; next, as embodied in structures which minimize
friction, such as well designed ships ; or as conducing to the effi-
ciency of tools and machines ; or deciding how best heat may be
radiated or light diffused. A word will follow as to modes of
conferring form, the influence on form of the materials employed,
and the undue vitality of old forms that should long ago have
bidden us good-by. Structures alike in shape may differ in
size. Bigness has its economies, and so has smallness. Both will
have brief attention, with a rapid survey of new materials which



2 INTRODUCTORY

enable a builder to rear towers or engines bolder in dimensions
than were hitherto possible.

Substance, as important as form, will next receive a glance.
First a word will be said about the properties of food, raiment,
shelter, weapons and tools. Then, the properties of fuels and
light-givers will be considered, as steadily improved in their ef-
fectiveness. How properties are modified by heat and electricity



Online LibraryGeorge IlesInventors at work, with chapters on discovery → online text (page 1 of 41)