Six of the seven strands forming each of the cables were laid around the seventh as a center, and when all were properly placed they were again saturated with oil and paint. After this, by another contrivance of the engineers, they were wound or wrapped with wire, like winding a rope cable with marlin, and thus the whole cable was made into a thoroughly compact, huge, round, iron rope. This was covered with numerous coats of paint to prevent the oxidation of the inner wires. The oleaginous coating of the wires, together with the small triangular spaces between them, would seem to reduce the destructive power of the vibrations to zero. But the vibrations are very greatly reduced and the stiffness of the structure is greatly increased by the use of a series of triangular stays, the triangle being the only geometrical figure whose angles cannot be shifted. There are sixty-four of these triangles. Their hypothenuses are formed by over-floor stays of wire rope reaching from the tops of the towers to different points in the lower floor, this latter, of course, forming their common base and the towers their altitude. The stays are fastened to the suspenders so as to form straight lines. As the towers and the floor are rigid and solid in the direction of the lines they represent, it follows that the intersections of the hypothenuses with the common base form so many stationary points in the latter. These stationary points present a powerful resistance to vibrations. The side trusses, with their system of diamond-work braces and the weight of the railway track on the upper bridge, also help to stiffen the structure. There are likewise fifty-six under stays or guys of wire rope fastened to the rocks below, designed to prevent upward and lateral vibrations. A heavy locomotive with twenty loaded cars produced a depression of the upward curvature of the track of nearly ten inches. The ordinary loads make a depression of only five inches. In Part II., attention was directed to a point on the American side of the river, just below this bridge, where the disintegration of the shale and abrasion of the superposed rock is strikingly exhibited. A singular phenomenon was witnessed here in 1863. A mass of rock and shale, about fifty feet long, twenty feet wide, and sixty feet deep, fell with a great crash. Directly following the fall a remarkable motion was developed in the bridge itself. A strong wave of motion passed through the whole structure from the American side to the opposite shore, and returned again to the same side.