There can be no question that the ship-building on the Red Sea, just like the architecture of the towns along its coast, is of Indian origin, all the timber required in Arabia being procured from India. At Khartoom, on the contrary, this art, although in many respects it has peculiarities of its own, has been derived from an Egyptian source. Taking their own special requirements into account, the boat-builders of Egypt have completely altered the structure and shape of their river boats. It must be borne in mind that the recurring cataracts, which interrupt the navigation of the Nubian Nile valley, rendered any ascent of the river a matter of difficulty, demanding indeed the most strenuous exertions. The cataracts are ten in number, and only recently have they been overcome by some small steam vessels of about 60-horse power. The only wood which is used in Khartoom for ship-building is that of the Sunt acacia (_A. nilotica_), which, though far heavier and harder than our oak, is the only wood which the soil of the Soudan supplies, which appears capable of being sawn into planks. But on account of the irregular texture and numerous branches of the trunk of this acacia, it is impossible to cut it into boards more than ten feet in length, and even these are rare. Masts and sail-yards, since those of deal seldom reach Khartoom, and then are of an exorbitant price, must be made by splicing together a number of small pieces. Externally these are bound with ox hide; but in violent gales they are extremely liable to start. Not only does the wood fail to be either straight or long, it is also so hard, that it requires to be sawn while it is green. The saw is an instrument so rarely employed throughout Nubia, that it is handled most unskilfully by the carpenters; as matter of course, there are neither steam-mills nor water-mills in Khartoom, and consequently the planks are cut without the faintest pretence to regularity.