2.] This is the earliest known specimen of _transparent glass_, which is not found in Egypt until the time of the Psammetichi.
The Assyrians used also opaque glass, which they colored, sometimes red, with the suboxide of copper, sometimes white, sometimes of other hues.
They seem not to have been able to form masses of glass of any considerable size; and thus the employment of the material must have been limited to a few ornamental, rather than useful, purposes.

A curious specimen is that of a pipe or tube, honey-combed externally, which Mr.Layard exhumed at Koyunjik, and of which the cut [PLATE LXXXIII., Fig.

1] is a rough representation.
An object found at Nimrud, in close connection with several glass vessels, is of a character sufficiently similar to render its introduction in this place not inappropriate.

This is a lens composed of rock crystal, about an inch and a half in diameter, and nearly an inch thick, having one plain and one convex surface, and somewhat rudely shaped and polished which, however gives a tolerably distinct focus at the distance of 4 1/2 inches from the plane side, and which may have been used either as a magnifying glass or to concentrate the rays of the sun.

The form is slightly oval, the longest diameter being one and six-tenths inch, the shortest one and four-tenths inch.