Page:Africa by Élisée Reclus, Volume 1.djvu/329

 CLIMATE OF KORDOFAN. UB reached the Nile through this fluvial chunncl. Throughout the course of the AbQ- Hableh the surplus waters form during the kharif season, that is to say from June to October, tein|>orary sheets of water which are usually raarkwl on the maps as El-Birket, or El-R^ihad, that is, '* Lukes," in a pre-eminent sense. But water rarely remains in this reservoir till the end of the dry season ; however, on digging in the sand to a depth of 8 or 10 feet, sufficient can be obtained to quench the thirst of both man and beast. Most of the other pools, generally called fulahn, are flooded only during the rainy season. In the inhabited region of Northern Eordofan, estimated by Prout at 17,200 square miles, there are neither rivers nor ponds, but only funnel-shaped wells sunk to a depth of 80 and even 160 feet, as far as the mica schist bed, which forms a layer through which the rain water, filtering through the light soil on the surface, cannot penetrate. The water in these wells is reached by steps cut round the excavation. The scientific exploration of this country has proved the existence of eight hundred wells, but at least two hundred of these are completely dry for half of the year, and the water of many is brackish or even salt. According to Escayrac, Lauture, and Matteucci, the general dessication of the country has been undoubtedly going on for many generations, and several wells which formerly furnished water in abundance have had to be abandoned. The annual rainfall, which is on the average 9 inches at El-Obeid, somewhat more in the mountains of the south, and less in those of the north, is not sufficient to fill all the wells sunk in the hollows. Hence entire villages are abandoned during the dry season. As soon as the dokhn, the only kind of millet which flourishes in this dry climate, has been harvested, the cultivators migrate to the wells which contain a little water throughout the year, and do not return to their fields till the com- mencement of the kharif. In the villages and towns water is a commercial article, and towards the end of the dry season it occasionally costs more than wine in wine- growing countries ; in 1873 a measure of two or three gallons was sold for a dollar. Climate of Eordofan. In spite of the altitude of Kordofdn, the temperature of this country is one of the hottest in the world. The season of intense heats commences in March, when the thermometer frequently rises to 105° F. in the shade, and the air mixed with the desert sand is almost suffocating. After the three months of the sef, or dry season, dense clouds are collected in the southern horizon, announcing the approach of the kharif. The beginning of June is ushered in by heavy showers, very violent but of short duration, with intervals of fine weather. The rainy season usually commences with atmospheric disturbances, whirlwinds rushing over the steppes ; but soon the aerial currents regain their equilibrium, and the south-west wind, a continuation of the south-east trade wind in the southern hemisphere, prevails over this part of the north, following the direction of the sun. During this season the temperature is maintained with a remarkable uniformity between 77° F. and 92° F., the oscillations of the thermometer seldom exceeding 12° F. Such a climate would be very agreeable, but for the vapours and miusmos with which the air is saturated,