CRANE. | Pumping Machinery. 319 
handle than are the wooden pumps, but on account offacid 
waters the wooden pumps are coming into more general use. 
Wooden column pipes are also replacing the iron suction and 
discharge pipes of the centrifugal pumps. A wooden cen- 
trifugal pump with wooden column pipe is shown in figure 1, 
plate L. 
Tes agate 
Rouen Sores 
ea 
oN apd 
— aaa 
— Besa 
Fig. 85. Side view of metal centrifugal pump. 
Several forms of these wooden pumps have been patented, 
one of the latest of which consists of an iron box which is 
lined with wood in which the spiral-shaped passage is cut; 
the iron box simply holds the wooden channel in position 
