Procure a large gallipot; place on the bottom, next the side furthest
from you, a sixpence, and next to it, but towards the centre, a
shilling; move to such a distance as will render the coins invisible;
then let another person pour water gently in, and as it rises in the
gallipot, it will cause both the sixpence and shilling to be seen,
without your approaching nearer to the gallipot, or moving it towards
you.