— 158 — is fixed, and motive power is supplied thereto by bulls. The entire structure is made of local timber by the village carpenter, who is also responsible for the frequent repairs required. The rope hangs freely in the water, and as the wheels revolve the pots are filled in succession, carried up and emptied as they pass over the top into a receiving trough, which in turn empties into the irrigation channel. The sakia is suitable for raising water to heights of from 3 to 8 metres, and is worked by one or two animals according to the lift, the number and size of the pots, and the number of teeth in the cog-wheel.

Costs of Sakia Irrigation.—With an average lift of 5 metres, the usual capacity of the sakia is some 30 m'' of water per hour, or, say, 240 m-' per diem with a single pair of bulls. According to local custom the hire of a pair of bulls with driver costs 200 milliemes per diem. The cost of water raised by sakia may consequently be stated as almost equivalent to that obtained by the use of the shadoof, but a greater lift is secured and a larger body of water is delivered.

The latter feature reduces losses from evaporation and seepage and a larger proportion of the water raised actually reaches the cultivated area. In 1913, 10,075 sakias were working in the Sudan.

Direct experiment has determined the duty of water in local circumstances to be about 470 m per watering per feddan for the clay loams constituting the majority of sakia lands on the river bank. This figure is based upon a discharge of from 5,000 to 6,000 gallons per minute as delivered by a modern pump through carefully-constructed canals, and if allowance be made for excessive losses where small streams of water are led through ill-constructed channels, it is certain that at least 500 m** will be required from sakia or shadoof. In either case, the duty is roughly equivalent to the output of two working days with the sakia, and the cost, according to local custom, is 400 milliemes.

A means of controlling this estimate is foimd in the payments made by tenants of sakia lands for water supplied by the owner. By local customs such a tenant would pay half his crop for the hire of the land and the water received from the sakia, and in addition would be responsible for half the land-tax. On this basis, if we take the yields per feddan on a 3-feddan holding, as follows : Cotton ... 3 kantars @ £E.3 = £E.10.500, the tenant would pay £E.5.250 Wheat ... 4 ardebs @, £E.l = £E.4.G00 „ „ 2.000 Dura ... 5 ardebs (Tv £E.0.600 = 3.000 „ „ 1.500 £E. 17.500 £E.8.750 If this cotton requires twelve waterings, the wheat six, and the dura four, the average number of waterings per feddan would be seven and a third. For rent and watering of one feddan the tenant pays £E.2.917 exclusive of land-tax. By common convention the rent alone amounts to a tithe of; the crop, so the cost of