reconstruct the Virginia channel-pier. Instead of the present spans of 210, 210, 214, and 327 feet to the Virginia channel-pier, we would have 210, 327, and 424 feet, being three spans instead of four. The last-mentioned span would be the new channel-span, and it would give a clear opening at low water of 399 feet.

The cost of making this change would be as follows:

One new channel-span, 424 feet

One new channel-pier:

2,944.5 cubic yards masonry, at $18....
368.5 cubic yards masonry, at $10..

Preparing foundations..

One new pier to replace No. 1:

$150,000 00

$53, 001 00

3, 685 00

56,686 00 5,000 00

1,624.7 cubic yards masonry from old pier,

One span 210 feet...

Preparing foundations...

Removing and rebuilding present channel-span, and framing false-work...

Deduct for spans available elsewhere:

15, 000 00

263,414 50

$35,000 00

One span 214 feet...

35,000 00

This estimate is somewhat larger than it would otherwise be, on account of the necessity of so conducting the changes as not to interfere with the traffic of the road. The method of making the changes indicated would probably be to replace pier No. 1 by a strong wooden pier straddling the present stone one, until the new and larger pier No. 1 is built up to the height of the present one, and truss No. 1 is seated on its new resting-place in an offset of the new pier. At the same time the new channel-pier could be built up to the same height. After this is done spans Nos. 2 and 3 and the channel-span could be replaced by trestle-work, while the new channel-pier is raised to its full height, the old channel-span removed, and the new channel-span is put in place. This might be done during low water in the summer, when coal-tows are not running. The work would probably require two seasons for its accomplishment. Some of the stones in piers 2 and 3 could be used in raising the new piers to their full height, but the greater portion of this material would be unavailable. It is possible that the new channel-span could be built outside of the present channel-span before its removal, and thus save filling the channel-space with false work; but this plan would not be altogether safe, and has not been considered in the esti mate. After the work is finished the rest of piers 2 and 3 can be removed, and the material in them can be sold, or used elsewhere on the road.

The material will about pay the cost of taking down. The new piers should be parallel with the present ones.

As this bridge was built at a time when such long spans were deemed almost impracticable by Congress, and was itself a marked advancement in bridge-building, and as it seems to have been built in good faith, the board hesitate to recommend that the modifications be made at the expense of the bridge company, and regard it as a question for Congress to consider whether in ordering the change for the benefit of navigation, it would not be proper to bear at least a part, if not the whole, of the expense of making it.

Bridge-building is subject to so many contingencies that may increase or diminish the cost, that it is impossible to make an estimate that can be considered as rigidly correct. We would recommend that if the Government pays for this work, the bridge company, to whom it should be intrusted, be directed to keep an exact account of all expenditures, to be audited in the usual way. If the actual cost should exceed the appropriation, an additional appropriation can be made to cover it.

WHEELING AND BRIDGEPORT BRIDGES.

These are highway bridges owned by the Wheeling and Belmont Bridge Company, and they connect that portion of the city of Wheeling which is built on Wheeling Island with the city proper, and with Bridgeport, in Belmont County, Ohio. The suspension bridge was commenced in February, 1848, and opened to travel in November, 1849. On the 17th of May, 1854, it was destroyed by a hurricane. It was at once rebuilt out of the old material, with a single track, and in 1860 it was again rebuilt, with an additional amount of wire in the cables and new suspending-rods. The height of the bridge was not altered during these changes.

These two bridges were erected under authority from the State of Virginia. A violent opposition to the suspension bridge was at once manifested by the river interest, and suit was brought against the bridge company by the State of Pennsylvania on the ground that the bridge was an obstruction to navigation and an illegal structure. The proceedings and testimony in this case are reported at length in the report to the Supreme Court of Special Commissioner R. Hyde Walworth, to whom was intrusted the duty of reporting upon the case. This report was printed at Saratoga Springs in 1851 by George White, and reference is made to it for many interesting details, that we must necessarily omit. Pending the suit, an act of Congress was passed August 31, 1852, (see Appendix A,) legalizing the suspension bridge and the Bridgeport bridge as post-routes and lawful structures.

THE SUSPENSION BRIDGE.

This is a "high" bridge on the suspension plan, made for highway traffic only. The highest point of its under surface is 914 feet above extreme low water, and 48 feet above highest water, the extreme oscillation of the river at this place being 434 feet; for a width of 155 feet, it has a height of 91 feet above low water, and for a width of 235 feet a clear headway of 90 feet. It is proper to remark that these widths, and the grades on the bridge-floor, are taken from the levels made by our own surveying party, and that they differ slightly from the measurements as given in Chancellor Walworth's report to the Supreme Court. These discrepancies may be partly due to changes made when

the bridge was rebuilt in 1854, and partly to the coldness of the weather at the time of our survey, whereby the suspension-cables were necessarily shortened, and the road-way elevated above its mean position. There is but one span to the bridge, the abutment on the eastern side being at the top of the high bank on which the city of Wheeling is built, and that on the other side being on the shore of the island, at the 12-foot line. The distance between the centers of the towers is 1,010 feet, and between the faces of the two abutments 980. The width of road-way is 16.4 feet, and each side-walk has a clear width of 4.2 feet, the entire width of the bridge, from out to out, being 28 feet. In low water the river does not occupy all the space between the abutments, and, consequently, the velocity at that time is not affected by the bridge. There are no spans between the towers and the two shores, as the eastern towers are on the natural surface, and a solid embankment, 341 feet in length, extends from the western towers to the natural surface of the island. The eastern towers are 15 by 15 at their bases, and 60 feet high above the road-way, making their tops 1523 feet above low water; they rest upon a single pier or abutment, which is built up to the height of the road-way, and they are connected on top by a masonry arch, 40 feet above the floor of the bridge. The western towers are 16 by 15 at their bases and 693 feet high, their tops being 1311⁄2 feet above low water; they are also built upon a single mass of masonry, and are similarly connected on top. The eastern abutment is founded upon the sand of the high bank upon which it is placed, and the western upon the river-gravel, a few feet above low-water mark. The bank under the eastern abutment is carefully paved with stone on edge, as also the shore of the island between the western abutment and low-water line.

In low water, as mentioned before, the bridge occupies no part of the water-way; in extreme high water the western abutment and the bridge approaches occupy 6,137 square feet, which is 14 per cent. of the entire high-water section at the bridge-site. The mean velocity of the river at this stage will not, however, be increased by this amount, as in extreme high water the entire width of the island between the two bridges is covered, and the water-way is ample.

The road-way at the face of the eastern abutment is 91.6 feet above low water. From this point the floor of the bridge rises with the following grades per 100 feet, viz, 2.56 for 50 feet, 2.54 for 50 feet, 2.06 for 50 feet, and 0.97 for 163 feet, at which point it attains its highest elevation of 95.34 feet above low water, having risen 3.74 feet in a distance of 1661. From this point the road-way descends with the following grades per 100 feet: 1.58 for 33 feet, 3.52 for 50 feet, 4.26 for 50 feet, 4.80 for 50 feet, 4.33 for 500 feet, 380 for 50 feet, and 3.55 for 84 feet, at which point it reaches the face of the western abutment, where the elevation of the road-way is 62 feet above low water, and 33 feet below the highest point of the bridge. The length of descending grade is 817! feet, measured on the floor.

The following tables are compiled from a record of from seventeen to twenty-one years, some of the months being missing in the earlier years. The record commences in 1840, is continuous to 1850, omits subsequent years to 1861, and thence is carried on to January 1, 1871, with some omissions during the period of the late war. The depths reported at Wheeling are those on the bar opposite the lower end of the city; at extreme low water there is one foot on this bar, and therefore the heights above low water are one foot less than those given in the table.

There have been no actual losses of boats at this bridge, though when first built, before steamboats had made arrangements to lower their chimneys, much damage, as well as loss by detention, was occasioned. This was entirely due to the efforts made to pass this bridge with chimneys standing, but since that has been given up, and boats on the upper river have been provided with hinged chimneys, there has been neither loss nor detention; we therefore have no changes to recommend in this bridge.

Its original cost was $161,594; the repairs on account of the hurricane of 1854 cost $37,000, and the partial reconstruction in 1860 cost $55,000.

THE BRIDGEPORT BRIDGE.

This bridge is over the western branch of the Ohio, which at Wheeling is divided by Wheeling (formerly Zane's) Island. It belongs to the same company as the suspension bridge, and was built under the same law of the State of Virginia and legalized by the same act of Congress. It is one of the common kind of wooden bridges, being a long truss strengthened by arches; it is in bad condition and needs rebuilding. This bridge is 638 feet in length and consists of three spans of about 212 feet each. Each span is composed of three trusses, with two roadways 10 feet in the clear between them, and two balcony sidewalks, 5 feet wide on the outside.

The channel on the west of Wheeling Island is no longer used for navigation. In order to improve the draught of water on Wheeling Bar, the western channel has been closed by a 6-foot dam just below the mouth of Indian Wheeling Creek. Under these circumstances it was unnecessary to make any current observations or to examine this bridge in detail.

The bridge is 53 feet above low water and 93 feet above highest water. Rafts and flats can at all times pass under, and no passage-way is required for steamboats.

Under these circumstances we have no changes to recommend in this bridge. Its original cost was $68,500.

BELLAIRE RAILROAD BRIDGE.

This is a single-track railway bridge and is being built by the Baltimore and Ohio Railroad Company under the general authority given by the act of July 14, 1862. It crosses the Ohio four miles below Wheeling, and connects the main stem of the Baltimore and Ohio Railroad with the Central Ohio. The bridge is a "high" bridge 4,001 feet long, and that portion over the river consists of six spans of the following dimensions, beginning on the Ohio side, viz, 210, 241, 348, 213, 212, and 211 feet, so that the bridge proper has a length of 1,435 feet. These dimensions are from center to center of piers, and are in excess of the clear water-way. The trusses are of the Linville or Keystone pattern, the two longest being "through" or "over-grade" and the others "deck or under-grade." The two "through" spans are both channel-spans, giving clear openings at low water of 322 and 220 feet, respectively. It will be noted that in both the bridges built by the Baltimore and Ohio Railroad Company the span adjacent to the main-channel span (required by law to give an opening of at least 220 feet) is made a channel-span as well as the longest span. This was doubtless the intent of Congress in directing that one of the spans adjacent to the channel-span should give a 220foot opening, but the act does not require the track to be on the bottom chord, and it is not so placed in either the Steubenville or Newport and Cincinnati bridge. Moreover in this bridge the law only requires a clear opening of 300 feet, while the company has voluntarily given 22 feet more. The bottom chords of the channel-spans are 911 feet above low water, but the track being supported on roadway bearers suspended below the bottom chords, the lowest line of the channel-spans is 90 feet above low water and 40 feet above highest water. There is no daily record of the stage of water kept in Bellaire, but levelings from the highest known water-marks make the maximum oscillation of the river surface 50 feet. The two main channel-piers Nos. 3 and 4 are each 91 feet above low water; No. 2, the Ohio pier of the 220-foot channel, is 90