158 Report oF THE BOTANIST OF THR 
the water-box constructed entirely of iron; only cylinders, glands 
and plungers being of bronze or bronze lined. As manufactured 
these pumps are geared back 5 to 1. All the gearing was re- 
moved and a small sprocket-wheel attached directly to crank 
shaft. This pump had the advantage over single-cylinder punaps 
of maintaining a nearly constant pressure without the aid of an 
air chamber. The position of the pump and the method of con- 
necting with tank and carrier are shown in Fig. 2, Plate XVII. 
CONNECTIONS. 
The pump used had 1} inch suction and discharge hence 14 
inch connections were used throughout. The method of connec- 
tion and arrangement of parts is shown in Fig. 2, Plate XVII. 
The use of a style of shaft and gearing given later would per- 
mit of the pump being placed nearer the tank and the use of 
shorter nipples. The distance between the first gate-valve and 
lock-out connecting to tank is 74 inches. The gate-valve, also the 
Ts, are standard trade lengths and sizes. A ], with valve con- 
nection as shown at h, Fig. 2, Plate XVII, was placed next to 
the pump for two purposes. It is desirable to run clean water 
through the pump without having to run it through the tank. 
Furthermore it was necessary to arrange to dragn the pump from 
both sides. This T and gate-valve also allow of emptying the 
tank through the suction pipe. 
A shut-off valve was placed in main supply pipe at wv, for 
the purpose of maintaining the pressure when the machine is 
stopped, also to hold the liquid in the carrier. This proved to be 
of little value. A JT was used in connecting main supply pipe 
with pump for the purpose of attaching a pressure valve and re- 
turn overflow pipe. At the same time the latter valve was used 
as means of draining the outer side of the pump and the main 
supply pipe. A power pump should be so geared that it will 
give good pressure no matter how slow the team moves, hence 
the necessity of a pressure valve to allow of pumping back into 
the tank when the speed of the machine is increased. The pres- 
