HANDSPIKE

, or Handspec, a lever or piece of ash, elm, or other strong wood, for raising by the hand great weights, &c. It is 5 or 6 feet long, cut thin and crooked at the lower end, that it may get the easier between things that are to be separated, or under any thing that is to be raised. It is better than a crow of iron, because its length allows a better poise.

HARD Bodies, are such as are absolutely inflexible to any pressure or percussion whatever: differing from soft bodies, whose parts yield and are easily moved amongst one another, without restoring themselves again; and from elastic bodies, the parts of which also yield and give way, but presently restore themselves again to their former state and situation. Hence, hard bodies do not bend, or indent, but break. It is probable however there are no bodies in nature that are absolutely or perfectly either hard, soft, or elastic; but all possessing these qualities, more or less, in some degree. M. Bernoulli goes so far as to say that Hardness, in the common sense, is absolutely impossible, being contrary to the law of continuity.

The laws of motion for hard bodies are the same as for soft ones, both being supposed to adhere together on their impact. And these two sorts of bodies might be comprized under the common name of Unelastic.