124 
EXPOSITION AT VIENNA. 
is safe to bum them, but the machine-made bricks, it is claimed, 
do not contain more than one-eight this amount of water. 
This permits expensive sheds and drying floors to be dis- 
carded, and renders it possible to manufacture continuously 
throughout the year. 
In Chicago, in 1872, there were some 400,000,000 of bricks 
made and used, and about half that number in 1873. The 
clay for the common brick is obtained from the excavations 
nlade for docks and slips along the river in the city. Fine 
front or facing bricks are made from clay procured at Gregg 
Station, eighteen miles from the city, on the Chicago, Bur 
lington and Quincy Railroad. Brick made from this clay in 
the Excelsiör Press are surpassed in color only by the finer 
grades of Philadelphia and St. Louis brick, but are as strong 
as any. 
Chambers’ Continuous Delivery Machine.—There were 
brick-making machines exhibited, belonging to the dass of 
tempcred clay continuous delivery machines, in which the 
clay, being properly mixed, is forcecl through a rectangular 
die in a continuous stream or column of clay, of the breadth 
and thickness required for brick. From this column of clay, 
bricks are cut off at proper intervals by wires, stretched 
in a frame, or by knives. The principle is the same as that 
of the machine invented and patented in the United States, by 
Cyrus Chambers, Jr., of Philadelphia. These machines have 
been in Operation for several years, and havo produced many 
millions of brick. 
The machine is constructed almost wholly of iron, and is 
made very strong. It receives the clay direct from the bank, 
tempers it with water, and forms it iuto bricks, with well- 
defined corners, and smooth, straight surfaces, at the rate of 
from tifty to eighty per minute, or from twenty-five to thirty- 
five thousand per day for ten hours. 
The tempering portion of the machine consists of a strong 
iron case, in which revolves a horizontal shaft, into which are 
set spiral 1}', strong tempering knives, or blades of steel, so 
that, as they pass through the clay, they move it forward 
their thickness, or whatever distance they may be set to do. 
The clay being stiff, and not having much water on it, is not