164 NEW YOEK STATE MTTSEUM 



functions of a spatter {See detailed account of * yards). All clays 

 are not sufficiently strong to permit drying on pallets. 



Btirning. — This is one of the most important steps in the 

 whole process of manufacture. ISTine tenths of the manu- 

 facturers who make common bricks by the soft mud process, 

 burn them in temporary, up-draft kilns, or scove kilns, as they 

 are properly called. The other one tenth use an up-draft kiin 

 which differs from the preceding in having permanent walls. 

 The following description of burning applies directly to scove 

 kilns, but the principle, whether it be a temporary or stationary 

 up-draft kiln, is practically the same. When the bricks are 

 thoroughly dry, they are set up and burnt in " arches," several 

 of which go to make up a kiln. The number of bricks in an 

 arch varies from 35,000 to 40,000. An arch is about 40 courses 

 high, and about 15 arches make up a kiln. The open portion 

 of the arch is about 14 courses high, and the bricks above the 

 arch are set three one way and then three on top at right 

 angles. They are kept slightly separated by putting small 

 pieces of clay in between them. The first row of brick on top 

 of the arch is called the tie course, and the first 14 courses, 

 including the tie course, above th6 arch are called the "lower 

 bench," and the rest of the courses .above are called the "upper 

 bench." When the arch and lower and upper benches have 

 been set, brick are laid flat over the top of the kiln ; this is the 

 " raw platting," and then on top of this is laid burnt bricks at 

 right angles to those of the raw platting; this is the "burnt 

 platting " Hanging from the roof of the kiln shed at the same 

 level are a number of bricks which serve as a guide for height 

 in building the kiln. A wall of two thicknesses of "double- 

 coal" brick is put around the outside of the kiln, scoving the 

 kiln it is called, and this is "daubed" over with mud. The 

 daub is to prevent any air entering except through the 

 doors. These latter consist of an iron frame about 14 inches 

 high, with an iron plate to close the opening; the frames 

 are set in the courses of double-coal brick, at the bot- 

 tom of the arch on both sides of the kiln. Double-coal 

 brick have six or seven times as much coal dust in them 

 as others, and are used for placing around the outside of 



