— H4 — Plant No. 2. Central Research Farm.

The irrigation of native-owned lands at Shambat, adjoining the farm, necessitated the purchase of a new pumping plant capable of providing the large amount of water demanded, which the old farm plant was entirely unable to supply.

It was thought advisable to instal a pump capable of irrigating both the farm and native lands, their combined areas being about 1,000 feddans.

In view of previous incessant trouble caused by the formation of sand banks, a permanently-fixed plant was thought inadvisable, and it was decided to float the engine and pump on a barge.

This system obviously possesses many advantages, the lifting and lowering of heavy pumps and pipes is obviated and, greatest recommendation of all, its mobility allows of rapid transfer to any section of the irrigated area.

As an instance of this, the plant after erection was uncoupled from its position and towed up the river a distance of two miles to save a valuable wheat crop which was jeopardised by engine failure.

The whole time taken in the operation did not exceed fifteen hours, and this fact, as a recommendation for the system of flotation, speaks for itself.

This plant contains three locomotive-type boilers, furnishing steam to a compound, high-speed, vertical, condensing engine of the open type.

The pump is of the centrifugal pattern, coupled directly to the face of the engine disc fly-wheel, and carries suction and delivery pipes of 18 inches diameter.

The condenser is of the jet type, fixed vertically behind the H.P. crosshead.

The engine cylinders are of Hi inches and 18 J; inches diameter, the pistons having a stroke of 11 inches.

The jet condenser air-pump bucket is 1 2 inches diameter, and has a stroke of 4 inches. Two boilers are fired, the third one being cleaned out and made ready for firing in rotation. Little trouble is experienced with scale, the river water being practically free from injurious scaling salts.

A feed-water heater is fitted for use when running non-condensing, though this is seldom done.

The movement of the floating barge necessitates the insertion of two short lengths of flexible leather pipe in the delivery pipe line, and the arrangement adopted may be readily seen from the illustration.

The flume runs for 400 metres in length before delivering water into the main canals, and has a maximum capacity of 20 cubic feet per second, sufficing for the irrigation of 1,000 feddans. The presence of a shallow khor between canals and river necessitated the flume being carried over the depression as a