— 25 — capacity, as determined by cross-section and fall. Similarly, an economic limit in the size of the pumping plant will be based on mechanical considerations.

Questions of control and supervision, together with that of the association of a number of units in one general scheme, should also receive consideration.

Avoiding reference to technical details, it may be provisionally stated that early experience would point to the unit of 1,000 feddans irrigated by 100-120 h.p.

engine and 18-inch pump, being one of a continuous series of similar areas, as affording collective opportunities of most economic working. While little additional economy can be effected by increasing the size of the pumping plant, which in most cases would take the form of additional power units, the losses from seepage and evaporation in an unduly extended canal system would be enhanced by the difficulty of obtaining an adequate fall for the main canal.

In the case cited, however, the cost of expert supervision should be divided over a series of adjacent units, which arrangement, coupled with the use of floating and interchangeable pumps, would obviate the necessity for a stand-by plant, which costly expejience has indicated to be essential on the self-contained estate. In the absence of such provision even temporary engine trouble in the middle of the cropping season may spell disaster and the loss of a year's work and outlay.

The Cost of a Pumping Station.—In existing circumstances, a pumping station to serve an area of 1,000 feddans can be organised in the neighbourhood of Khartoum at a total cost of approximately £E. 1,800, including landed cost of machinery, erection and provision of a float to carry the plant. The cost of headworks will naturally vary with the contour of the land, but should not exceed £E.100 in a majority of cases, while canalisation has been actually completed for such an area at an outlay of £E.30O. Preliminary surveys, the provision of bridges, modules and weir-gauges and other incidental expenses may involve an additional expenditure of £E.200, making a capital charge in all of £E.2.400 per feddan on land which is worth at least £E.20. The remaining mortgagable balance should suffice as ample security for the cultivator's working capital, as soon as agricultural credit has been placed upon a sound footing.

Pending consideration of this vital requirement, local experience has shown that he is often borrowing money at impossible rates of interest and burdening himself irretrievably with debt.* Demarcation.—The irregular size and shape of sakia holdings constitute a somewhat serious difficulty, and compUqate canalisation and accountancy.

* " As long as there was no bank in existence in the Sudan the Government granted to the peasants small advances, mostly for a period of three years, against payments of 7J per cent, interest per annum, under the supervision of the local authorities, provided the money was required for the purchase of cattle and agricultural implements, and for the construction of water lifts. In 1906, the National Bank of Egypt, which has agencies in Khartoum, Suakin, and Port Sudan, introduced the system of granting peasants advances against mortgage of their crops, and of protecting them against usurious rates of interest and artificially kept-down prices. Generally speaking, however, agricultural credit in the Sudan is very difficult to obtain for the small farmer, except at an excessive rate of interest." (Cotton in Egypt and the Sudan.)