From Damer, Burckhardt proceeded to Shendy, where he passed a month, during which time no one suspected him to be an infidel. Shendy had grown in importance since Bruce's visit, and now consisted of about a thousand houses. Considerable trade was carried on--grass, slaves, and cattle taking the place of specie. The principal marketable commodities were gum, ivory, gold, and ostrich feathers. According to Burckhardt, the number of slaves sold yearly at Shendy amounts to 5000; 2500 of these are for Arabia, 400 for Egypt, 1000 for Dongola and the districts of the Red Sea. The traveller employed his time during his stay at Sennaar in collecting information about that kingdom. Amongst other curious things, he was told that the king having one day invited the ambassador of Mehemet Ali to a cavalry review, which he considered rather formidable, the envoy in his turn begged the king to witness part of the Turkish artillery exercises. But at the outset of the performance--at the discharge of two small mounted guns--cavalry, infantry, spectators, courtiers, and the king himself, fled in terror. Burckhardt sold his wares, and then, worn out by the persecutions of the Egyptian merchants who were his companions, he joined the caravan at Suakin, intending to traverse the unknown district between that town and Shendy. From Suakin he meant to set out for Mecca, hoping to find the Hadji useful to him in the realization of his projects. "The Hadji," he says, "form one powerful body, and every member is protected, because if one is attacked the whole number take up arms." The caravan which Burckhardt now joined consisted of 150 merchants and 300 slaves. Two hundred camels were employed to convey heavy bales of "danmour," a stuff manufactured in Sennaar, and cargoes of tobacco. The first object of interest to the travellers was the Atbara, a tributary of the Nile, whose banks, with their verdant trees, were grateful to the eye after the sandy desert. The course of the river was followed as far as the fertile district of Taka. During the journey the white skin of the pretended sheik Ibrahim (it will be remembered that this was the name assumed by Burckhardt) attracted much attention from the female population, who were little accustomed to the sight of Arabs. "One day," relates the traveller, "a girl of the country, of whom I had been buying onions, offered to give me an extra quantity if I would remove my turban, and show her my head. I demanded eight more onions, which she immediately produced. As I removed my turban, and exposed my white and close-shaven head to view, she sprang back in horror and dismay. I asked her jokingly if she would not like a husband with a similar head, to which she replied with much energy, and many expressions of disgust, that she would prefer the ugliest slave ever brought from Darfur."