MACHINE

, denotes any thing that serves to augment, or to regulate moving powers: or it is any body destined to produce motion, so as to save either time or force. The word, in Greek, signifies an Invention, or Art: and hence, in strictness, a machine is something that consists more in art and invention, than in the strength and solidity of the materials; for which reason it is that the inventors of machines are called Ingenieurs, or engineers.

Machines are either simple or compound. The simple machines are the seven mechanical powers, viz, the lever, balance, pulley, wheel-and-axle, wedge, screw, and inclined plane; which are otherwise called the simple mechanic powers.

These simple machines serve for different purposes, according to the different structures of them; and it is the business of the skilful mechanist to choose them, and combine them, in the manner that may be best adapted to produce the desired effect. The lever is a very handy machine for many purposes, and its power immediately varied as the occasion may require; when weights are to be raised only a little way, such as stones out of quarries, &c. On the other hand, the wheel-and-axle serves to raise weights from the greatest depth, or to the greatest height. Pulleys, being easily carried, are therefore much employed in ships. The balance is useful for ascertaining an equality of weight. The wedge is excellent for separating the parts of bodies; and being impelled by the force of percussion, it is incomparably greater than the other powers. The screw is useful for compressing or squeezing bodies together, and also for raifing very heavy weights to a small height; its great friction is even of considerable use, to preserve the effect already produced by the machine.

Compound Machine, is formed from these simple machines, combined together for different purposes. The number of compound machines is almost infinite; and yet it would seem that the Ancients went far beyond the Moderns in the powers and effects of them; especially their machines of war and architecture.

Accurate descriptions and drawings of machines would be a very curious and useful work. But to make a collection of this kind as beneficial as possible, it should contain also an analysis of them; pointing out their advantages and disadvantages, with the reasons of the constructions; also the general problems implied in these constructions, with their solutions, should be noticed. Though a complete work of this kind be still wanting, yet many curious and useful particulars may be gathered from Strada, Besson, Beroaldus, Augustinus de Ramellis, Bockler, Leupold, Beyer, Limpergh, Van Zyl, Perault, and others; a short account of whose works may be found in Wolfii Commentatio de Præcipuis Scriptis Mathematicis; Elem. Mathes, Univ. tom. 5, pa. 84. To these may be added, Belidor's Architecture Hydraulique, Desaguliers's Course of Experimental Philosophy, and Emerson's Mechanics. The Royal Academy of Sciences at Paris have also given a collection of machines and inventions approved of by them. This work, published by M. Gallon, consists of 6 volumes in quarto, containing engraved draughts of the machines, with their descriptions annexed.

, Architectonical, is an assemblage of pieces of wood so disposed as that, by means of ropes and pulleys, a small number of men may raise great loads, and lay them in their places: such as cranes, &c.—— It is hard to conceive what sort of machines the Ancients must have used to raise those immense stones found in some of the antique buildings; as some of those still found in the walls of Balbeck in Turkey, the ancient Heliopolis, which are 63 feet long, 12 feet broad, and 12 feet thick, and which must weigh 6 or 7 hundred tons a piece.

Blowing Machine. See Bellows.

Boylcian Machine. Mr. Boyle's Air-Pump.

Electrical Machine. See Electrical Machine.

Wind Machine. See Anemometer, and Wind Machine.

Hydraulic, or Water Machine, is used either to signify a simple Machine, serving to conduct or raise water; as a sluice, pump, and the like, or several of these acting together, to produce some extraordinary effect; as the

Machine of Marli. See Marli. See also Fire- engine, Steam-engine, and Water-works.

Military Machines, among the Ancients, were of| three kinds: the first serving to launch arrows, as the scorpion; or javelins, as the catapult; or stones, as the balista; or fiery darts, as the pyrabolus: the 2d sort serving to beat down walls, as the battering ram and terebra: and the 3d sort to shelter those who approach the enemy's wall, as the tortoise or testudo, the vinea, and the towers of wood. See the respective articles.

The Machines of war now in use, consist in artillery, including cannon, mortars, petards, &c.