[Illustration]
Nearly fill a glass tumbler with water, and hold it, with your back
to the window, above the level of the eye, as in the engraving. Then
look obliquely as in the direction E, _a_, _c_, and you will see the
whole surface shining like burnished silver, with a strong metallic
reflection; and any object, as a spoon, A C B, immersed in the water,
will have its immersed part C B, reflected on the surface, as in a
mirror, but with a brilliancy far surpassing that which can be obtained
from quicksilver, or from the most highly-polished metals.