LIV. W. E. COOK. 



the bell being fixed concentrically with the cylinder in which the 

 upper piston works. 



Under pressure of top piston, the lower piston descends for 

 2 feet, when it is stopped. The moulded pipe is then cut off with 

 a fine wire, and removed on the board with the interior collar 

 mould still in it. Another board is placed on the piston head, 

 another interior collar mould is placed in position, the lower piston 

 is raised till the board touches the inner collar mould, and the 

 operations are then repeated. 



After moulding, the pipes are partially dried in sheds or in 

 partly cooled kilns before burning. In the kilns they are stacked 

 as close as possible, the smaller sizes being placed inside the larger 

 ones. The ^ipes are also stacked one above another to the full 

 height of the kiln. After burning for about a week, and while 

 the material is white hot, salt is thrown into the kiln with the 

 last three or four charges of fuel to form the glaze, and shortly 

 after the burning ends. The kilns and contents are allowed to 

 cool slowly to the temperature of the outside air very nearly, and 

 the pipes are then ready for use. 



Testing Machine. 



The machine used for testing the pipes for crushing, consists of 

 an oil ram which descends on a block of wood placed on the 

 middle of the pipe lying horizontally in a bed of moist sand, con- 

 tained in a wrought iron box about 3 feet square. At each of 

 the four corners of this box, a large screw is fixed vertically. The 

 upper and working part of the machine is carried on these four 

 screws, so that it can be raised or lowered to suit the different 

 sizes of pipe, varying from 6 inch to 24 inch internal diameter. 

 The raising or lowering is effected by a horizontal band wheel on 

 one screw. Turning this handle causes a toothed wheel of small 

 diameter to revolve, and in doing so to turn a toothed wheel of 

 large diameter, which causes a toothed wheel of small diameter to 

 revolve on each of the other three vertical screws. In this way 

 all four corners are raised or lowered equally. Resting on these 

 four toothed wheels, and screwed by bolts to the under side of the 



