CLAY MANUFACTURES. 693 
1 to stroke, one to sand and place the molds, two to carry off, and one odd 
man. Making 12,000 brick a day, or half the capacity of the machine, 
these six men do the work of three molders, six off-bearers and one or 
two odd hands. The products are well-shaped brick, with square edges 
and corners, but are always rough on one side where they were stroked. 
A machine-made brick can usually be distinguished by this peculiarity. 
The work done on the whole is good for brick to be used in second 
class work, such as boiler settings, flue linings etc., as all machine- 
made brick are, because,they all use plastic clays. The cost of the 
machine and its running power are both small. 
The molding done, the pressing and drying are next in order. The 
drying of hand-made brick may be done in two ways—by hot air or by 
a hot floor; the latter is much the more important and common in its 
use. One of the principal features of a fire-brick works is the dry- 
ing floor. 
Some of the best examples in use are built as follows: Across the end 
of the floor, which is nearly always rectangular, is dug a pit some six feet 
below the general level. In the wall of this pit are set fireplaces at 
intervals of from 5 to 6 ft. These fireplaces proceed inward about a 
yard, and then break up into from three to five parallel flues. These 
flues are about 10 inches square, and are separated by 4 inches of brick. 
The flues traverse the whole distance of the floor and unite in a chimney 
or chimneys at the other end, which must be high enough to make every 
individual flue draw. These flues are covered by square tile 12 inches 
ona side; they are placed 4 thick at the fire end of the flue, and run 
down to 1 at the opposite end. This is done to equalize the heat of the 
floor. The depth of the flues is so arranged that their unequal covering 
brings the tile to a level plane; on this is spread a cement adapted to 
this use; it is made of basic furnace cinder and sandy clay in equal 
parts, ground fine, and wet. Ifthe cinder is not basic enough, lime is 
added; the mixture sets very hard and will last four or five years if 
well treated. Sometimes the flues are covered with one thickness of 
tile all over, and are then leveled up with sand and another layer of tile. 
This is undoubtedly cheaper, and is also as even a distributer of heat as 
a plain tile floor would be, but is rather more apt to cause trouble in 
repairing by blocking up the flues with sand. The custom is to keep 
the floors hot constantly ; the mass of the body heated makes this easy 
to be done. The fuel used is coal slack in almost all cases, as its com- 
