Levelling System, a term which since the commencement of the French revolution has been grossly misinterpreted, and cannot be found in any civilized country to answer any other purpose than that of delusion; such was the calumny raised by the patricians of Rome, when they having plundered the soldiers of their lands and appropriated to themselves; when the people complained they were thus reproached; the agrarian law which proposed only to restore the lands to the owners, was called a levelling system; but the people were robbed and the consequence was the ultimate ruin of Roman liberty, and Rome itself; the word Jacobin in modern times has superseded leveller.
LEVER, a balance which rests upon a certain determinate point called a fulcrum.
Lever in mechanics, an inflective line, rod, or beam, moveable about, or upon a fixed point, called the prop or fulcrum, upon one end of which is the weight to be raised, at the other end is the power applied to raise it; as the hand, &c.
Since the momentum of the weight and power are as the quantities of matter in each, multiplied by their respective celerities; and the celerities are as the distances from the centre of motion, and also as the spaces passed through in a perpendicular direction in the same time, it must follow, that there will be an equilibrium between the weight and power, when they are to each other reciprocally as the distances from the centre, or as the celerities of the motions, or as the perpendicular ascent or descent in the same time; and this universally in all mechanical powers whatsoever, and which is therefore the fundamental principle of all mechanics. See [Mechanical Powers].
LEVET, the blast of a trumpet.
LEVIER, Fr. Lever. The French writers having been more explicit on this head than any of our lexicographers, we shall extract the following passages as conducive to general information. The levier or lever is an instrument made of wood or iron, by whose means the heaviest weights may be raised with few hands. When the lever is made of iron, it is called pince or crow. The lever may be considered as the first of all machines. Wheels, pullies, capstans, &c. act only by the power it possesses. The lever must be looked upon as a straight line, which has three principal points, namely, the one on which the load is placed, and which is to be raised, the appui or rest which is the centre round which it turns, and which the French mechanics call orgueil, and lastly the human arm, which is the power that puts the lever into motion. The different arrangements or disposition which is given to these three points, or rather the unequal distances at which they are placed, occasion the force that is collectively displayed.
Belidor makes the following remarks on this useful machine. It is an inflexible bar which must be considered as having no weight in itself, upon which three powers are made to act in three different points in such a manner, that the action of two powers must be directly opposed to the one that resists them. The point where the opposing power acts is called the point d’appui.
Levier, in artillery, a wedge.
Levier de pointage, Fr. a wedge to assist in pointing pieces of ordnance.
LEVIERS de support, Fr. a wedge by which cannon is raised to a certain line of direction.