Mechanics: the Science of Machinery

Volume Five

P. F. COLLIER & SON COMPANY NEW YORK

Copyright 1922 BY P. F. COLLIER & SON COMPANY

MANUFACTURED IN U. S. A.

MECHANICS

THE SCIENCE OF MACHINERY

A. RUSSELL BOND FORMERLY MANAGING EDITOR, SCIENTIFIC AMERICAN

P. F. COLLIER & SON COMPANY NEW YORK

PREFACE

ALTHOUGH strictly speaking the term “Mechanics” applies to that branch of Physics that deals with the actions of forces on material bodies, originally the word had a broader meaning embracing all machinery and mechanical inventions. To-day popular usage is restoring to the term its original broad interpretation, and it is in this popular but rather unorthodox sense that “Mechanics” has been chosen as the title of this book; for although certain elementary principles of mechanics are described and explained, the major portion of the book deals with machines and their evolution to their present stage of perfection.

Machines are man’s creation, and yet in a sense the man of to-day is a machine product; for modern civilization owes its material and in large measure its esthetic development to machinery. The story of machinery, from primitive man’s first attempts to augment his physical powers with mechanical aids down to the present era of gigantic, steel-muscled machinery and marvelously intricate mechanisms, is the story of human progress. It is this story that we have endeavored to tell in the following pages, but the subject is too large to be covered in a single volume or even a dozen volumes. Under the circumstances we have been obliged to confine ourselves to a mere outline, selecting certain avenues of progress more marked than others and presenting brief sketch maps of them. We have aimed in this way to give a bird’s-eye view of the whole story of human progress in things material.

The book has not been written for the mechanical engineer, but for the layman who would learn of the mechanical contrivances that contribute to his material welfare; hence technical terms have been avoided, as far as possible, and where unavoidable have been explained and defined.

A. RUSSELL BOND

CONTENTS

CHAPTER PAGE

I. TOOL-MAKING ANIMALS 9 II. THE ANATOMY OF A MACHINE 20 III. MACHINES FOR MAKING MACHINES 42 IV. COUNTING SECONDS 57 V. PUTTING RIVERS TO WORK 75 VI. LIQUID LEVERS AND GEARS 94 VII. AIR vs. WATER 109 VIII. AIR SPRINGS AND CUSHIONS 126 IX. POWER FROM HEAT 139 X. BURNING FUEL IN THE ENGINE CYLINDER 155 XI. WHEN COAL AND OIL ARE EXHAUSTED 171 XII. INVASION OF THE SEA 182 XIII. SLIDING, ROLLING, WALKING, AND CREEPING 203 XIV. INVASION OF THE SKY 219 XV. HELPING THE FARMER 239 XVI. MACHINING THE EARTH 251 XVII. FROM FIBER TO FABRIC 268 XVIII. THE MAKING OF PAPER 289 XIX. TYPESETTING AND PRINTING MACHINERY 300 XX. CAST IRON, WROUGHT IRON, AND STEEL 314 XXI. ANIMATED MACHINERY 326 XXII. HEAT VACUUMS 345 XXIII. ENGINES OF DESTRUCTION 359 XXIV. SUMMARY OF MECHANICAL PROGRESS 376

LIST OF ILLUSTRATIONS

THE DROP FORGE--FORGING A STEEL PLATE Frontispiece

FACING PAGE

RAISING WATER WITH A CHAIN OF POTS--A PRIMITIVE PUMP USED IN EGYPT 32

HORSE-OPERATED CHAIN PUMP USED IN GREECE 32

MULTIPLE SPINDLE DRILL IN A MOTOR CAR FACTORY 33

BUCKET OF A GIANT DREDGE WITH ITS JAWS WIDE OPEN 64

GOLD DREDGE EATING ITS WAY THROUGH RIVER SANDS 65

SUCTION DREDGE EXCAVATING A CHANNEL AND BUILDING NEW LAND 65

AIR LOCK OF A PNEUMATIC CAISSON 96

SUBAQUEOUS TUNNEL SHOWING THE SHIELD IN THE BACKGROUND 97

WHARF PROTECTED BY A PNEUMATIC BREAKWATER 128

SUN-POWER PLANT IN EGYPT 129

CLOSE-UP OF ONE OF THE REFLECTORS OF A SUN-POWER PLANT 129

GIANT CAPRONI HYDROAEROPLANE 160

CONCRETE STEAMSHIP “FAITH” 161

“VIRGINIAN,” THE LARGEST LOCOMOTIVE IN THE WORLD 161

LOOM PROVIDED WITH A JACQUARD ATTACHMENT 224

BATTERY OF MULE SPINNING FRAMES 225

JACQUARD ATTACHMENT FOR LOOM 225

DIGGING A TRENCH WITH A MACHINE OF THE CHAIN TYPE 256

MULTIPLE PLOWING ON A WESTERN WHEAT FIELD 257

SAWING LOGS OF PULPWOOD INTO 16-INCH LENGTHS 288

HEATER IN A PULP MILL WHERE THE WOOD PULP IS MIXED WITH CLAY 288

MODERN FOURDRINIER PAPER-MAKING MACHINES 289

MOLTEN METAL FROM A BLAST FURNACE 320

BESSEMER CONVERTER BLOWING AIR THROUGH A MASS OF MOLTEN IRON 320

STEEL BEAM PASSING THROUGH THE FINISHING ROLLS 321

COMPOSITOR AT WORK ON A LINOTYPE MACHINE 352

THE OPTOPHONE, WHICH ENABLES THE BLIND TO READ PRINT 353

BLIND MAN READING WITH HIS EARS 353

CHAPTER I. Tool-Making Animals

TOOL-MAKING ANIMALS

WHEN we review the marvelous achievements of modern civilization we are quite willing to agree with the ancient psalmist that man is “little lower than the angels.” But at the other end of the scale our complacency is liable to receive a rude shock; apparently the boundary between man and beast is not so very easy to draw.

We used to be told that one important superiority of mankind lies in the fact that he makes use of tools, while the beast never uses any implement except those that nature has furnished him as part of his own organism. But a gorilla will throw stones at his enemy; and he knows how to brandish a club and use it with telling force. Some of the apes are known to use sticks to knock down fruit which is out of the reach of their hands, and they will crack nuts with a stone. Clearly these animals are tool users. A very intelligent orang-utan in the Bronx Zoölogical Garden, New York, after trying for days to wrench off a bracket from the wall of his cage eventually used the horizontal bar of his trapeze as a lever and with it pried the offending bracket from its fastenings. Here was real invention and the discovery of the principle of leverage. The great black arara cockatoo of New Guinea uses his beak as a saw to weaken the shells of hard nuts, and to keep his bill from slipping off the smooth shell he is ingenious enough to wrap a leaf around the nut to hold it steady.

Even in the insect world we find creatures resourceful enough to make use of tools. Prof. Franz Doflein of the University of Breslau tells of an interesting study of certain ants, known as the Oecophylla smaragdina, who build their nests in bushes by fastening leaves together with fine threads. But the ants that build the nests cannot spin these threads, because they possess no spinning glands. They must depend upon their larvæ for this product. When a rent was made in one of these nests, a band of the tiny creatures ranged themselves side by side along the torn edge of the leaf and reached across the gap until they could catch hold of the opposite edge with their mandibles. Then they drew back step by step, with perfect teamwork, until the two edges were brought together. In the meantime, other ants had rushed to the nursery and each one had picked up a larva, not with the idea of bearing it off to safety, but in order that the babies might spin the thread which the adult ants were unable to do. The larvæ were carried to the breach in the nest and moved back and forth across the rent. They were pressed first against one side of the tear and then the other and all the while were squeezed tightly, evidently with the purpose of making them spin. Gradually a fine silky web was woven across the torn leaf and eventually the rent was completely patched.

Unquestionably these little ants are tool-using animals, because they make their larvæ serve as spinning spindles and also as weavers’ shuttles. However, this can hardly be cited as a point in common with even the lowest type of man, for the ants merely use the tools they find at their disposal. They certainly cannot be credited with having produced or even improved the tool which they use, whereas even in the most primitive of men we find that the tools used are not only carefully selected for the work to be performed, but are actually, shaped, be it ever so crudely, to suit the job.

Clearly we must shift the boundary between man and beast, distinguishing the former as the creature who artificially improves his tools. But even here it is not absolutely certain that the boundary will stand. Wilhelm Boelsche, a well-known German writer on natural history, calls attention to the “blacksmith woodpecker” which will thrust hard pine nuts into cracks in the trunk of a tree, so that they are held as if in a vise, enabling the bird to operate upon the seed more easily. Furthermore, this woodpecker will actually make a hole in the tree to receive the nut if there is not a hole or crack handy, so that evidently this animal does produce or artificially improve the tool that it uses.

There are a few such examples in nature, just enough to cast a bit of uncertainty on the boundary we have set. But although the actual line of demarcation may not be clear, there is no question but that the lowest type of humanity now existent, or of which we have any record, is or was a tool maker. Chipped stones evidently fashioned by man for some useful purpose are found even in the remains of the Middle Tertiary Epoch. The spirit of inquiry, of experiment, of invention, and the ambition to dominate over other members of the animal kingdom or over the obstacles imposed by nature, are to be found more or less active among all peoples, no matter how lowly a position they may occupy in the scale of civilization.

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