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withdrawn with such speed and dexterity, that the piece of money will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.