4 
Tlic Economical Application 
to be worked on the liquid manuip system ; tlie ground should 
be level on the surface (not in high ridges), and divided into 
four 5-acre fields ; supposing the li(juid has to be forced through 
the pipes by pumps, two will be required with plungers of 
6^ inches diameter, having a stroke of 2 feet, with a speed of 
20 revolutions per minute, and throwing 70 gallons per minute.* 
The plungers should be of cast-iron, the valves of brass, and so 
placed as to be easily accessible in case of requiring examination ; 
a small brass cup connected by a cock to the barrel of the pump, 
•close under the stuffing-box, will be found useful to prevent the 
accumulation of air in the pumps, and also to facilitate their 
starting. A large air-vessel should be placed on the delivery- 
pipe, as close to the pumps as possible, and a safety-valve as well, 
i need not suggest an arrangement of pumps, &c., as I presume in 
an undertaking of this sort most men would place themselves under 
the guidance of a person experienced in such matters. The centri- 
fugal pump would be a most economical and efficient machine for 
this purpose ; under ordinary pressure it performs a greater per- 
centage of work in proportion to the power employed than can 
be got out of the common lift and force pump ; the economy of 
first cost, as well as of power, — the absence of all valves and air 
vessels,— ease of motion and freedom from jerks, — the almost total 
^impossibility of stoppages from choking (some solid substances 
of moderate size can be forced through with perfect impunity), — 
these are advantages which should command an extensive employ- 
ment of tbese pumps. 
When the supply of water cannot be made to flow naturally 
into the tanks, the pumps must be looked to for raising the 
supply needed ; an additional suction-pipe and cocks will gene- 
Tally effect this. A branch-pipe from the rising main should be 
taken into both the tanks ; and by a simple arrangement of stop- 
cocks, water or liquid manure may occasionally be discharged 
into either tank with such force, before or during the time oi 
pumping out, that little sediment will remain behind. 
The fluid should only be charged with that amount of matter in 
suspension which is due to its bulk. It is a mistake to put on the 
liquid in a thick state, as it not only stops up the pores of the 
soil by forming an incrustation on the surface, but is also in an 
unfit state for immediate assimilation by the plants. The chief 
value of liquid manure arises from its prompt action and imme- 
* There are many advantages in having a good long stroke, as with the same 
power the number of strokes made in a given time is thereby diminished, and 
therefore the inertia of the fluij less frequently to be overcome ; the quantity of 
water which at each closing of the fixed valve returns below it is less, and the 
shakings in the joints of the mechanism, which are produced by changes in the 
direction of the motion, are decreased. 
