Smithsonian Report, 1948.—Glaze PLATE 1 
1. AN OPTICAL GLASS POT, AND ITS STIRRING THIMBLE, SET IN A POT 
ARCH PREPARATORY TO BURNING 
2. TWO MELTING FURNACES AT THE NATIONAL BUREAU OF STANDARDS 
The pot of glass in furnace 5 is being stirred and its temperature is being determined by the furnaceman 
by means of an optical pyrometer. The pot in furnace 6 is being filled with batch. Photographs courtesy 
National Bureau of Standards. 
