Note 13 — Chapter XV
Reading edition
Every one knows the simple experiment in which a coin lying at the bottom of an empty basin, and hidden from the eye by its side, becomes visible when a certain quantity of water has been poured in. This is an example of refraction. The rays of light coming from the coin ought not to reach the eye, on account of the basin's side being in the way; yet by the action of the water they are refracted, or bent over its edge, in such a manner that they do.