Wherever cattle and stock are numerous, farmyard manure is used, as well as the guano from the immense colonies of pigeons, kept for the purpose in specially built pigeon-lofts throughout Egypt. Between Halfa and Kena there are inexhaustive supplies of nitrates in the desert, and north of Kena the mounds which mark the sites of ancient cities, like Abydos, Ashmunên, Medinet, and the rest, serve the same purpose. The ruins of the past are thus valued by the agriculturist not less than by the archæologist, perhaps even more so; for lands in proximity to them are rented higher in consequence. Year by year more attention is now paid to the dressing of the soil, as perennial irrigation is more understood and more studied; besides the natural resources of the country, an increasing amount of manures is imported from abroad, and there is little doubt that the growing tendency in this direction will continue. But all preparation of the soil is worse than useless labour unless the necessary amount of water can be provided. This amount varies both with the nature of the crop, the season of the year, and the position of the land. The critical time is, of course, the summer, when the supply of water is least and the heat is greatest, and, of course, in Upper Egypt, where the sun is strongest, and the loss by evaporation consequently greater, the demand is more urgent than in the Delta. The total amount of cultivable land in Egypt is 6,250,000 acres. Before the completion of the new works, to which period all the figures in this chapter refer, the total nominally under cultivation was about 5,750,000 acres. Of this, Upper Egypt claimed 2,320,000—viz., 587,000 nominally under perennial irrigation, and 1,732,000, including 1,435,000 under basin irrigation every year, and 297,000 of Nile berms, which are only flooded once in six or seven years, and at other times irrigated directly from the Nile by means of shadoofs and water-wheels. Of the whole of this area only about 20 to 30 per cent. produce double crops in the year; for the amount of perennial irrigation is but small, and, although the whole of the Fayoum—329,000 acres—was supposed to be perennially irrigated, so faulty was the water-supply that the summer crops were only about 30 per cent. of the whole, instead of 50 per cent., which is the rule in the Delta. It seems, indeed, as though matters had been arranged expressly for the benefit of the tourist; it is Upper Egypt in the winter season that he goes to see, and it is then that the fields are green with corn, clover, and other crops. The following table shows the different crops, and the acreage devoted to them at the different seasons in Upper Egypt: _Season._ _Acreage._ _Crops._ Summer 372,500 Sugar, cotton, vegetables, melons, summer sorghum (or millet). Flood 530,000 Flood sorghum, rice.