Farms and Villages. 
55 
attached to it. The lower end of the bar is jointed on to a lever, 
attached to the valve, and the upper end to the horizontal arms 
of a bell-crank lever, the vertical arm of which is fitted with a 
counter-weight, and forms a "tumbler" arrangement, that is, 
it is free to move a certain distance on the axis of the horizontal 
arm between stops. As the water falls in the tank, the float 
slides down the rod till it rests on the lower stop ; its weight 
then pulls the bell-crank lever over, and as soon as the upright 
weighted arm passes the centre, it falls over against a stop on the 
horizontal arm and depresses that without affecting the float, 
till the valve is closed and the ram stopped. As the water rises, 
the float travels up the rod to the upper stop, and by its buoyancy 
throws the upright arm of the bell-crank over on to the opposite 
side, where its weight holds the valve open till the water sinks 
again to its lowest level. 
The duty which hydraulic-rams are capable of performing 
depends upon the fall, the rate of inclination of the injection- 
pipe, and the relation w hich the lift bears to the fall ; but it 
maybe taken at 80 per cent, duty at proportions of lift to fall of 
4 to 1, down to about 50 per cent, for the highest ratio. The 
most useful size of ram has a 3-inch injection-pipe, and, while 
consuming a constant quantity of about 25 gallons per minute, 
will discharge according to the following table : — 
Proportion of Lift 
Gallons delivered 
toFaU. 
per minute. 
4 
5' 
5 
3- 5 
6 
2- 9 
7 
2- 4 
8 
2- 
9 
1- 7 
10 
1- 4 
11 
1- 2 
12 
1- 1 
13 
0-95 
14 
0-85 
15 
0-75 
As with pumps, the friction of the rising main must be added 
to the actual lift in estimating the quantity of water the machine 
will deliver. 
Rams are made of various sizes, but they do not work well 
when very large, say, with injection-pipes more than 6-inch 
diameter. They use water, and raise it approximately in pro- 
portion to the area of their injection-pipes, that is, as the square 
of their diameters. Thus, for example, a ram with a 2-inch 
