340 QUEENSLAND AGRICULTURAL JOURNAL. [1 Nov., 1902. 
The following mechanical contrivances are also valuable for raising large 
bodies of water to a small height, but they differ from water lifts in that they 
are capable of forcing water to a limited height. Of these, the most important 
is the Centrifugal Pump. 
_ This pump has the power of sucking water for a few feet and forcing it a 
height of 20 to 25 feet. To do good work, the suction should not exceed 5 feet 
and the force 25 feet, a total lift of 30 feet, but given increased power the 
pump will work up to as much as 40 feet of total lift, but beyond this, other 
pumps are to be preferred. © 
Under favourable conditions no pump will do more work for the power 
employed than the centrifugal, or is better adapted for irrigation purposes, 
especially when a large body of water is required, such as in the case of a large 
orchard or garden on level land adjoining creeks, lagoons, &c. 1+ will deliver the 
water at or a few feet above the level of the bank of the creek, &c., as desired, 
provided the total lift does not exceed that already mentioned, and the water 
can be distributed thence by means of gravitation. 
A centrifugal pump requires to be driven at a high speed, hence a combined 
engine and boiler is best adapted to work it when a large supply of water is 
required, but small pumps may be worked by a high speed horse-gear or geared 
windmill. 
Full particulars as to the price of different sized pumps and of the 
machines necessary to work them can be obtained from any implement house, 
the cost depending entirely on the quantity of water required. 
Rorary Pumes. 
Like the centrifugal, these pumps require to be worked by an engine, 
horse-gear, or geared windmill, but are not driven at anything like the same 
speed. They answer the same purposes as the centrifugal, but will force 
the water to a considerably greater height if necessary, but the total lift 
should not exceed 60 to 70 feet. They, however, do their best work at 
moderate lifts, as even at the heights mentioned other pumps to be mentioned 
later are much more satisfactory. They are made in small sizes, and are 
useful for the small grower who only requires a supply of 2,001 or 3,000 
gsllons an hour. They are inexpensive, not liable to get out of order, and are 
easily worked. They are obtainable from most machinery agents. 
There is also one other type of pump suitable for moderate lifts—viz., the 
ulsometer, which does its best work when the total lift does not exceed 40 
eet, though it will force water toa greater height, but to do so requires a 
considerable increase in power. It is a direct acting steam pump, though its 
principles and mechanical construction are entirely different from ordinary 
pumps, and requires a boiler to work it. It is an easy machine to work, and not 
liable to get out of order. In actual practice a pulsometer driven by a 4 nominal 
horse-power boiler will lift from 3,5U0 to 4,000 gallons an hour 40 feet. 
Wenowcome to the question of where water has to be raised from a greater or 
lesser depth to the surface, and then forced to the land that itis desired to irrigate. 
This necessitates the use of totally different pumps to those already 
described-—viz., that; of combined lift and force pumps. It is essential that 
pumps of this type shall be placed as near the water to be raised as possible, 
for though they will lift water by suctiona height of some 30 feet theoretically 
it is found in practice that it is not safe to allow more than a maximum lift of 
25 feet; and even this should be reduced whenever possible, as the shorter the 
suction the less chance of leakage, and any leakage, no matter how small, 
greatly reduces the capacity of the pump. ‘These pumps lift by suction, and 
then force to any height or distance that may be necessary, the quantity of 
water required and the height to which it has to be forced governing the size of 
the pump and the power necessary to work it. These pumps will lift water 
from any source of supply, and are made in all sizes from the small hand pump 
capable of raising a sufficient supply for household purposes to the most 
powerful steam pumps capable of raising many thousands of gallons per 
