make a tight fit.

To charge the generator, proceed as follows: Open the vent valve by turning
the handle which extends over the filling tube until it stands at a right
angle with the generator. Open the valve in the water filling pipe, and
through this fill with water until it runs out of the overflow pipe of the
drainage chamber, then close the valve in the water filling pipe and vent
valve. Remove the carbide filling plugs and fill the hopper with
1-1/4"x3/8" carbide ("nut" size). Then replace the plugs and the
safety-locking lever chains. Now rewind the motor weight. Run the pressure
up to about five pounds by raising the controlling diaphragm valve lever
by hand (Figure 12, lever marked _E_). Then raise the blow-off lever,
allowing the gas to blow off until the gauge shows about two pounds; this
to clear the generator of air mixture. Then run the pressure up to about
eight pounds by raising the controlling valve lever _E_, or until
this controlling lever rests against the upper wing of the fan governor,
and prevents operation of the feed motor. After this is done, the motor
will operate automatically as the gas is consumed.

[Illustration: Figure 11.--Pressure Generator (Davis Bournonville).
_A_, Feed motor weight;
_B_, Carbide feed motor;
_C_, Motor Control diaphragm;
_D_, Carbide hopper;
_E_, Carbide feed disc;
_F_, Overflow pipe;
_G_, Overflow pipe seal;
_H_, Overflow pipe valve;
_J_, Filling funnel;
_K_, Hydraulic valve;