Glass vessels, by placing a hot prepared cameo, of the usual composition, upon the hot manufactured vessel; a small piece of liquid Glass is dropped on it, and becomes welded; and, if rubbed while hot, the upper coat of fused Glass will be spread as thinly as possible upon and around the cameo, behind which are driven any air bubbles that may be entrapped; thus completely isolating the device between the two Glasses. These incrustations require very careful annealing.

Pressing is a mechanical operation, unknown to the