This part of the work was given out in contract to Mr. John Brown, on the Canada side, and to Messrs. Latham and Gage, on the New York side. lts inspection was placed under the charge of the late Mr. George Watson, who fell a victim to the cholera last year. The base of the towers presents a rock face, the stones are large, and well bonded and bedded. The beds of the backing were all cut true, and all the stones were laid in a heavy bed of cement mortar, and the joints grouted. In tile towers above a uniform bond has been observed, all the blocks being dimension stone. The backing was bedded with the same care as the face. To increase the solidity of this work still more, the upper courses were dowelled. The entire security of this masonry may be relied upon. Without expending much labour upon its appearance, nothing has been spared to secure its strength.

The base of the lower work at the level of the lower floor is 60 + 20 feet, pierced by an arch of 19 feet wide, which forms the entrance to the lower bridge. Each of the four towers is 15 feet square at the base, 60 feet high above the arch, and 8 feet square at the top, therefore has a top surface of 64 square feet. The limestone, of which this masonry is built, will support a pressure of 500 tons upon every superficial foot, without crushing. Whilst the greatest weight that can fall upon one tower will rarely exceed 600 tons, it would require a pressure of more than 32,000 tons to crush the top course.

The base and towers on the New York side contain 1350 cubic yards, which weigh about 3000 tons. Add to this the weight of the superstructure of 1000 tons, and we have a total of 4000 tons, in a compact and solid mass. For lateral stability, I have relied entirely upon this weight and the central direction of the forces, which act upon the top course. The inclination of the tangents of the suspension cables very nearly coincides with the angle of the land cables, consequently their united tensions will produce a vertical pressure through the axis of each tower.

As regards the apparent lateral pressure of the cables upon the towers, the danger is only imaginary and not real. The strongly inclined position of the upper or railroad cables, which insures that remarkable degree of lateral firmness so observable in the upper floor, appears to produce a lateral pressure towards the inside, which these small masses of masonry could not long resist. When, however, the observer takes his stand, either on top of the towers or back of the anchorage, in line with the anchor cables, he will discover that all is right and as it should be. A medium line between the two anchor cables, when continued towards the river, will be found to correspond precisely with a mean line between the tangents of the two suspension cables, consequently, the force growing out of the united tension of the cables, is bound to keep within a vertical plane, which descends through the axis of the towers. The horizontal projection of the cables on the plan, shows the perfect safety of this arrangement. By connecting the towers by an arch, and forming a gateway, instead of isolated columns, the appearance of the want of lateral stability could have been avoided. But this would have changed the whole plan of masonry, and its cost would have been more than doubled, without adding to its safety.

The character of the anchor masonry is that of strong rubble, laid in cement mortar, no regard being had to outside appearance.