the directions of the current showed that, above the bridge, it made angles of from 14° to 150 with the axes of the channel piers, and that below, the angles varied from 101° to 150. General G. K. Warren made similar observations in June, 1868, at a time when the river was 4 feet above low water, and found that the current then made an angle with the Ohio channel pier of 15°.

It is well known to all navigators that the direction of the current through the channel-span of this bridge varies with the stage of water in the river. Its direction in low and in moderate water is almost entirely determined by the middle, or ferry bar, on the edge of which the Virginia channel pier is located. As the river rises, this bar has less influence, and, in high stages, its effect is imperceptible, the river current being entirely determined by the shape of the bend above. At 4 feet above low water, as just mentioned, the current draws on the Ohio channel pier, striking it under an angle of 150. At 9 feet, this angle is about 1410. At higher stages, the current, it is said, commences to straighten. At 13 feet it is about parallel to the piers, and, as the depth increases, it draws more and more on the Virginia pier. These changes in direction are among the greatest sources of trouble to tow-boat pilots, as their fleets are managed mainly by the current, and therefore navigators must be well posted as to the exact stages of water at the bridge, and the resulting direction of the current, before attempting the passage. Add to this the narrowness of the space and the possible obscurity of the atmosphere from river fogs and mists, or from the smoke of the mills at Steubenville, and the reasons for the accidents at this bridge are at once apparent. The range of the current cannot be less than 30°; from 15° on one side of the axis of the piers to at least the same on the other side. If the range be equal on both sides, (we have no high-water observations by which to determine this point,) it follows that the piers occupy the mean position, and therefore are "parallel to the current of the river, as near as practicable." But it is evident from these facts that the locality is one entirely unsuitable for a bridge, besides the fact that it is on one of the permanent bars, where, at low stages, the river is most shoal and most swift. At such places we might naturally expect the greatest variations in the course of the current. In the pools, on the contrary, the direction of the current is very nearly the same at all stages, and at such places only should bridges be allowed to cross. But it must also be stated that these principles were not well known at the time when this bridge was located, and the company building it very naturally chose the locality that best suited their general line. At low water the natural section of the river is 3,179 square feet, of which 604 square feet, or 19 per cent., is occupied by the piers of the bridge. At high water the total section between the high-water marks is 77,189 square feet, of which 7,342 square feet, or 93 per cent., is occupied by the piers and the riprap about them. The approximate discharge of the river at the time of the observations, as measured 300 feet above the bridge, was 37,858 cubic feet per second, with a mean velocity of 3.883 feet per second, or 2.65 miles per hour. At this stage the waterway at the bridge is as great as it is above the bridge, the increased depth between the piers compensating for the partial occupation of the section. The maximum observed velocity through the channel space was 4.35 feet per second, or 3 miles per hour. The channel span is what is known as a "through" or "over-grade" bridge, with the track on the bottom chord. The other spans are "deck" or "under-grade," with the track on the top chord. In consequence of this arrangement, the tops of the channel piers are 89 feet above low water, and the tops

of the other piers are 663 feet above; the difference between them being the depth of the trusses of the short spans. There is neither grade nor curvature on the bridge.

The channel piers are of substantial stone masonry, with a section on top 42 by 17 feet, which includes a coping projecting 4 inches; and at low-water line of 783 by 233 feet. The sides have the usual batter of inch per foot, and the tops have the usual cut-stone coping. The up-stream ends are provided with ice breakers, with a batter of 9 inches to the foot, and a triangular cross section rising to a height of 41 feet above low water; above the ice breaker, the pier has a semicircular section, with a batter of inch to the foot. The down-stream ends are semi-circular in section, with the usual batter of inch per foot. The other piers are smaller, 30.7 by 10.7 on top, but they are similar in shape. The foundation of the Virginia channel pier consists of three courses of pine timber one foot thick, decked over with four-inch plank. All the other piers have under them four thicknesses of timber. The natural bed was excavated so that the lowest water would always cover this deck one foot deep. The stone is laid on this in courses two feet thick. The timber projects one foot beyond the masonry. The riprap, protecting the timber platform, extends out from 6 to 7 feet, and rises up from one to four feet above low water. The Virginia channel pier stands in shoal water, and is well protected naturally; but the Ohio pier stands in the deepest water of the cross section, and the river bottom abreast of this pier is on a level with the lowest timbers of its foundation. Nothing but the riprap that surrounds it saves it from destruction. It is proper to remark here that none of the foundations are as deep as they should be, and most of the piers owe their stability entirely to riprap. One of the piers deflected 2 feet from the perpendicular while the bridge was being constructed, but a quick and liberal use of riprap prevented further inclination, and it is now proba bly as safe as the others. While we believe that ordinary floods will not imperil the safety of this structure, yet it is not impossible that an ice gorge at the bridge itself might, at some future day, do it great damage. The excuse alleged for the defective foundation of this bridge is the poverty of the company that originally began it. Unfortunately these defects cannot be remedied excepting by outside protection, and that has been freely used.

The bottom chord of the channel span is 90 feet above low water, and 45 feet above highest water, the greatest known rise being 45 feet. This leaves a sufficient headway under the bridge at all stages, and there is no complaint against it on account of height. No record is kept of the daily stage of water at Steubenville.

The railroad track being on elevated ground on both sides of the river, there was no difficulty in making the approaches to the bridge, which consist of short and inexpensive embankments. In this respect it has a more advantageous site than any other railroad bridge over the Ohio. This bridge has been a serious hinderance to navigation ever since it was built, and the causes are quite clear. The great variability in the river current, and the narrowness of the channel span, which, at most stages, is oblique to the current, and therefore practically much lessened, are in themselves sufficient to account for the trouble heretofore experi· enced in passing this bridge. An official statement from the president of the Pittsburg Coal Exchange of the losses hitherto incurred by col lision with the piers of this and of other bridges over the Ohio River, is given in Appendix B. It will be seen that the actual loss by collision with the piers of this bridge, from its construction to the present time,

amounts to $61,588. As navigators have in reality no remedy against the bridge companies, but must bear these losses themselves, it is manifest that, though the losses may sometimes be attributed to inexperience and lack of skill, they can never be considered as the result of design. It is unquestionable that bridges over the Ohio (though a public necessity) are a source of danger and loss to the navigation interest. Cases will sometimes arise where the best of skill will not avail, as in a recent accident at Bellaire, where the bridge was só obscured by the smoke of the rolling mills on the banks that when the steamboat "Star," with ten barges of coal, came to the channel span, the pilot was unable to see the piers, and struck one of them, thereby losing the boat and barges, and the lives of two of the crew. Besides this, it is considered almost impossible to take fleets through these bridges at night, and as a rule they are laid up for daylight, which, of course, increases the length and expense of the trip.

The Steubenville bridge is so very much the worst one on the river that a due regard for the right of the people to have the navigation of the Ohio not needlessly endangered requires that this bridge should be changed.

An examination of the map and profile of this bridge shows that the Virginia channel pier stands in shoal water near the foot of the ferry bar, while the Ohio pier has deep water on both sides of it. If this, alone, were to determine the question, the latter should be removed. Before coming to a decision on this matter, numbers of prominent coalboat pilots and owners were consulted, as the change was intended specially for their benefit, and they were unanimous in the request that the Ohio pier be moved, leaving the other where it is. Their principal reason, besides the one above mentioned, was that in coming out of the bend above at Wills's Creek they are in the habit of keeping their fleets as near as possible to the Ohio shore, for the double purpose of securing the shore as a guide to facilitate steering and in order that there may be less danger of drifting into the bend on the Virginia side below the bridge.

Under these circumstances the board of engineers are of the opinion that the channel span of this bridge should be widened toward the Ohio shore.

In order to make the proposed changes at the least possible cost they have thought it best to utilize the present wide span, throwing out the second and third spans from the Ohio abutment, and introducing one new wide span. The two spans thrown out 210 and 214 feet would not be wasted, as they are of dimensions that are frequently employed and could readily be sold or used elsewhere on the road. The first pier would require rebuilding, as the change would bring upon it a much greater weight than that which it now carries, and it would have to be raised to the height of the channel pier in order to carry the present channel truss, with an offset 22 feet lower for the first deck span. In our estimate we give this pier the same dimensions as one of the present channel piers, though it is probable that a less thickness would do as well. The second and third piers would necessarily be thrown out, being replaced by one nearly midway between them. The whole cost of making the change would then be the reconstruction of the first pier and the building of a new channel pier, the cost of one new span of 424 feet, and of the removal and reërection of the present channel span. This expense would be somewhat reduced by the value of the two spans that would be saved for use elsewhere. It would not be necessary to 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 the change would be as follows:

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

33,72-50 3,000 00 15,000.00

263,414 54

70,000 00
7,000 00

63,000.00

200, 414 50

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 estimate. 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 roadway 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 that between the faces of the two abutments 980 feet. The width of roadway is 16.4 feet, and each sidewalk has a clear width of 4.2 feet, the entire width of the bridge from out to out being 28 feet.