The first experiment is a very simple one. Partly fill the bottle with
water; then take one of the corks, make a slit in one end in the
direction of its length, into which insert a coin. Next stick two forks
into the cork, on opposite sides and near the other end, at angles of
about 30deg. With the forks so placed, as balance-weights, it is an easy
matter to balance the coin upon one edge of the mouth of the bottle, as
in Fig. 1. With a steady hand it is also possible to execute the
effective termination shown in the lower portion of the same
illustration--_i.e._, to slope the bottle gradually so as to pour out a
glass of the contents, retaining the while the coin in equilibrium upon
the neck of the bottle.