Elementary Statics (Paperback)

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. 1871 Excerpt: ...pressure at B equal to P. Then for equilibrium we must have WxAC=PxBC=P (AB-AU); .AC=p.AB. Hence, making W= 1 lb., 2 lbs, 3 lbs.... successively, we shall be able to mark upon the steelyard the corresponding positions of the fulcrum; and when the beam is thus graduated we shall be able to ascertain the weight of any given body suspended from A, by observing the mark of graduation which is nearest to the fulcrum. 7. It will be seen that the distances between the successive marks of graduation on the common steelyard are equal, but on the Danish unequal. In fact, the distances of the successive marks of graduation from A, the extremity of the beam which supports W, in the common steelyard form an arithmetical progression, in the Danish they form an harmonical. 8. The Windlass. The principle of the lever may be conveniently applied for the purpose of lifting or sustaining great weights; this is done by means of a windlass or capstan. The windlass is used for such purposes as that of raising an anchor. It may be described as a strong cylindrical beam, moveable about a horizontal axis, the extremities being inserted into two strong upright pieces in which they are capable of turning freely. One end of a rope is coiled partially round the windlass, and to the other end is attached the anchor or the weight to be raised; a number of apertures are made in the windlass perpendicular to its axis, and in these are inserted short bars called handspikes; by means of these it is evident that the windlass may be made to revolve, and when by its revolution a handspike is brought inconveniently low it is taken out and reinserted in a more convenient place. The windlass in the figure is represented with fixed bars, instead of handspikes, which in some applications of the mach...