A Treatise of Mechanics, Theoretical, Practical, and Descriptive

by Olinthus Gregory

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1815. ... CHAPTER IV. On the Mechanical Powers. 126. Def. A machine is any thing that serves to augment or to regulate moving forces or powers; or it is any body destined to motion so as to save either time or force; or, we may in general apply the term machines to the material agents by the aid of which forces operate one upon another, and which when employed to second the efforts of certain powers enable them to overcome others which may be more considerable. 127. Machines are distinguished into simple and compound. The only machines which we think can be strictly called simple, are the lever, the inclined plane, and it has been customary, however, to cousider as simple machines those of w hich all compound machines are found to be constituted, paid into which when their combined powers are estimated they must be divided m the investigation; these are in number six, viz. the lever, the whiel and axle, the pulley, the inclined plane, the screw, and the wedge. These are most commonly known by the name of the mechanical powers. In all these the mechanical advantage arise.' from distributing the power to be overcome among the different part of the machine, so that the part sustained by the contrary power shall bear but a small ratio to the thus a power incapable of communicating motion to a body, or of supporting its pressure, without mechanical assistance, may effect its designed purpose by transferring a part of the weight upon a fulcrum, distributing it among a system of pulleys, placing it upon an inclined plane, screw, &c. 128. Forces of different kinds may, it is obvious, be made to operate so as to counteract each other's effects, by the intervention of as for example, the muscular force of men and animals may be applied to mac...

210 pages, Paperback

Published February 2, 2012

About the author

Olinthus Gilbert Gregory (29 January 1774 – 2 February 1841) was an English mathematician, author and editor.

He was born on 29 January 1774 at Yaxley in Huntingdonshire. Having been educated by Richard Weston, a Leicester botanist, in 1793 he published a treatise, Lessons Astronomical and Philosophical. Having settled at Cambridge in 1796, Gregory first acted as sub-editor on the Cambridge Intelligencer, and then opened a booksellers shop. In 1802 he obtained an appointment as mathematical master at the Royal Military Academy, Woolwich through the influence of Charles Hutton, to whose notice he had been brought by a manuscript on the Use of the Sliding Rule; and when Hutton resigned in 1807 Gregory succeeded him in the professorship. Failing health obliged him to retire in 1838, and he died at Woolwich on 2 February 1841.