Page:Economic History of Virginia Vol 1.djvu/132

 and the mouth being calculated to be four feet, which permitted vessels of as much as three hundred tons in burden to make their way, in spite of the accumulation of logs on the floor of the stream, to a point about five miles below the place where all further advance was suddenly interrupted. In this stretch of five miles before the Falls were reached, the river was navigable for barges of a draught not exceeding six feet. On the north side of the river below the Falls, soundings disclosed a depth here and there of five and six fathoms. Throughout the whole of the upper course of the Powhatan, large and small islands were discovered, and so numerous were they at the Falls that the forest seemed to extend in an unbroken line of verdure across the breadth of the river. Islet after islet arose among the tumbling waters, suggesting to the English voyagers their admirable suitability as sites for water-mills, a use, however, to which they have never been put, although a great city has arisen on the eastern shore of the main stream. The fact that most of these islets have been subject to overflow in the sudden inundations of the river has probably acted as a deterring influence; canals have also brought the propulsive force of the Falls to mills situated on the mainland many feet above the danger of floods in the stream below. The water of the Powhatan, in spite of the regular flow of the tide, was entirely devoid of brackishness in the vicinity of the