TO SHOW THE VELOCITY OF MOTION.
Take a long hollow stalk or reed, suspend it horizontally by two loops of single hairs; by striking it with a sharp quick stroke at a point nearly in the centre, between the hairs, it may be cut through without breaking either of them. The hairs in this case would have been ruptured, if they had partaken of the force applied to the stalk; but the division of the latter being affected before the impulse could be propagated to the hairs, they must consequently remain unbroken.
A smart blow, with a slight wand or hollow reed on the edge of a glass tumbler, would break the wand, without injury to the glass.
Lay a small piece of money upon a card placed over the mouth of a glass tumbler, and resting upon the rim of the glass. The card may be withdrawn with such speed and dexterity, that the piece of money will not be removed laterally, but will drop into the glass.