[Illustration]
A similar experiment may be performed on a larger scale by bending up a
longer and proportionately stouter piece of wire, and substituting for
the coin a small plate and for the ring a bunch of keys--Fig. 15--or a
larger plate and a tea-cup. In the latter case the weight of the tea-cup
may be built up to counter-balance the plate by dropping a number of
coins one by one into the cup until the required weight is obtained.