File:The conquest of nature (1911) (14763170511).jpg

Identifier: conquestofnature00will (find matches)
Title: The conquest of nature
Year: 1911 (1910s)
Authors: Williams, Henry Smith, 1863- Williams, Edward Huntington, 1868-1944, joint author
Subjects: Industrial arts Machinery
Publisher: New York and London, The Goodhue company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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ityis sufficiently obvious once the thing has been done.In point of fact, it so enormously reduces the frictionthat a man may convey ten times the burden with itsaid that he can without it. But how was the primitiveman, with his small knowledge of mechanics, to predictsuch a result? In point of fact, of course, he madeno such prediction. Doubtless his attention wasfirst called to the utility of rolling bodies by a chanceobservation of dragging a burden along a pebbly beach,or over rolling stones. The observation of logs orround stones rolling down a hiU might also have stimu-lated the imagination of some inventive genius. Probably logs placed beneath heavy weights, suchas are still employed sometimes in moving houses, wereutiHzed now and again for many generations beforethe idea of a narrow section of a log adjusted on anaxis was evolved. But be that as it may, this idea wasput into practise before the historic period begins, andwe find the earHest civihzed races of which we have (56)
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THE ANIMAL MACHINE record—those, namely, of Old Egypt and of Old Baby-lonia—in full possession of the principle of the wheelas applied to vehicles. Modem mechanics have, ofcourse, improved the mechanism as regards details,but the wheels depicted in Old Egyptian and Babylonianinscriptions are curiously similar to the most modemtypes. Indeed, the wheel is a striking illustrationof a mechanism which continued century after centuryto serve the purposes of the practical worker, with seem-ingly no prospect of displacement. MODIFIED LEVERS For the rest, the mechanisms which primitive manlearned early to use in adding to his working efficiency,and which are still used by the hand laborer, are vir-tually all modifications of our famihar type-implement,the lever. A moments reflection will show that thediversified purposes of the crowbar, hoe, shovel, ham-mer, drill, chisel, are all accomphshed with the aid ofthe same principles. The crowbar, for example,enables man to regain the power which

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