Derr being the principal place in Nubia, and the usual residence of the chiefs, whenever they are not travelling about, is resorted to by strangers, and carries on some commerce. The dates of Derr and Ibrim are much esteemed in Egypt, and the merchants of Esne and Assouan export many ship-loads from hence in autumn, when the height of the waters insures a quick passage down the river. Young date trees are also carried hence to Egypt, as the trees propagated there from seed soon degenerate. The dates are paid for in Dhourra, and in coarse linen and Melayes, of Esne and Siout manufacture; but if the harvest of Dhourra has been abundant in Nubia, the payment is then made in Spanish dollars. The state of commercial intercourse in this country is, however, very bad; dates, for example, bought at Derr, even when paid for in cash, leave, when sold at Cairo, a clear profit, after paying all expenses, of at least 400 per cent. Dhourra, on the contrary, carried from Assouan to Derr, yields there 100 per cent. profit. The hundred weight of dates at Derr is worth about eight shillings. The common currency is the Moud, or small measure of Dhourra, by which every article of low value is estimated. The dollar is rather an article of exchange than a currency. Piastres and paras have only been known here since the invasion of the Mamelouks. The village of Derr stands in a grove of date trees, and consists of about two hundred houses. Hassan Kashef and his two brothers have each a good house. The greater part of the inhabitants are Turks, the descendants of the Bosnian soldiers who were sent by Sultan Selym to take possession of the country.[23]