The possession of the Nile was of extraordinary advantage to Egypt, not merely as the source of fertility, but as a means of rapid communication. One of the greatest impediments to progress and civilization which Nature offers to man in regions which he has not yet subdued to his will, is the difficulty of locomotion and of transport. Mountains, forests, torrents, marshes, jungles, are the curses of "new countries," forming, until they have been cut through, bridged over, or tunnelled under, insurmountable barriers, hindering commerce and causing hatreds through isolation. Egypt had from the first a broad road driven through it from end to end--a road seven hundred miles long, and seldom much less than a mile wide--which allowed of ready and rapid communication between the remotest parts of the kingdom. Rivers, indeed, are of no use as arteries of commerce or vehicles for locomotion until men have invented ships or boats, or at least rafts, to descend and ascend them; but the Egyptians were acquainted with the use of boats and rafts from a very remote period, and took to the water like a brood of ducks or a parcel of South Sea Islanders. Thirty-two centuries ago an Egyptian king built a temple on the confines of the Mediterranean entirely of stone which he floated down the Nile for six hundred and fifty miles from the quarries of Assouan (Syêné); and the passage up the river is for a considerable portion of the year as easy as the passage down. Northerly winds--the famous "Etesian gales"--prevail in Egypt during the whole of the summer and autumn, and by hoisting a sail it is almost always possible to ascend the stream at a good pace. If the sail be dropped, the current will at all times take a vessel down-stream; and thus boats, and even vessels of a large size, pass up and down the water-way with equal facility.