118 On the Manufacture of Glass. 
The furnace is supported at the four corners, by pillars of 
masonry and upon each of these it is usual to build a cal- 
cining oven, with a flue communicating with the furnace. 
door where he deposits the other in the same manner ; con- 
tinuing his travels, he encircles the furnace, and again sup- 
plies himself with wood. Thus moving at the rate of about 
three miles an hour, he continues his route supplying regular- 
ly the furnace with fuel, until he is relieved at the end of six 
hours, by another stoaker, who is likewise relieved by the first. 
We usually employ, and always prefer for this business su- 
annuated blowers, as they are familiar with the manner 
in which the fire should be regulated, so as to produce the 
quickest melt, with the least quantity of fuel. Although 
it appears a very simple operation, yet two hours of time 
will be gained in every melt, by employing an experienced 
stoaker. . . 
_ Melting.—When the furnace has arrived at what is cal- 
led a white heat, the vitrifiable materials, (or mixing,) are 
thrown into the pots through the rings, by means of an iron 
shovel made for the purpose. After the pots are filled, the 
cookies are replaced, and the fire increased to its max- 
imum, and regularly continued, until the materials are per- _ 
fectly fused, during which operation, the superintendant of 
the furnace or master stoaker as he is termed, occasionally 
examines the glass with an iron rod, to ascertain the state 
of the melt, and that it is going on prosperously. The fu- 
sion of the first laying in being accomplished, the pots are 
again filled with mixing—and this process is repeated, until 
the melted metal, is within three inches of the top of the 
o insure an intimate mixture of the different layers 
of glee, and form a perfectly homogeneous mass ; it is now 
stirre : we. 
_ This is done either by means of a billet of wood or wh: 
is better a potatoe put on the end of an-iron rod. Thi 
