three purposes named, was only eighty-five thousand dollars. If, therefore, we had attempted to apply a little of this sum to every point on the river where improvements are practicable, it would have been all frittered away without the accomplishment of any practical good; hence, it was suggested that the balance, not applicable to "surveys," and "removing obstructions," should be divided at a few points on the Upper Ohio, where the navigation suffered most from shoals during the low-water periods. Wheeling Island, Marietta Island, and other points, heretofore made known to you, were found to be worse than many other places, some of which had already been improved by the government, and they were accordingly designated as points deserving immediate attention on that account, and work was advertised and let. This brings me to the point I desire to present. If the government were prepared to enter immediately upon the construction of works for the radical permanent improvement of the entire river, any material expenditures for the minor improvement of the navigation at Wheeling Island might be indefinitely deferred.

On the other hand, if it could be known that the river would never receive such radical improvement, the greater would be the necessity for prosecuting the minor improvements, including such works as may, under all the circumstances, be deemed best at Wheeling Island.

Hitherto, as you are aware, appropriations toward the improvement of the Ohio River, compared with other national expenditures, have been quite limited, so that the fund, when divided between the surveys, the removing of obstructions, and actual works of improvements, has not been sufficient to warrant the commencement of works excepting at a comparatively few places, as already indicated.

Thus the process is slow, and on this system the improvement of the river, even by the present mode, would occupy a number of years. We asked for larger appropriations than have heretofore been made, in the hope of pushing forward the most needed works simultaneously at all points along the whole river; but Congress has reduced those amounts so materially that we have been obliged to confine our operations to suit the small sums appropriated, and to go on only with the worst places, as they show themselves.

For the reasons included above, it might be deemed expedient at this time to modify the plans so far as they may properly admit of it, at those points where the proposed works appear to bear hard upon important private interests.

The

In the case of Wheeling Island, however, if the private interests on the Virginia side to be benefited by the proposed dam were to be com pared with the private interests claimed to be injured on the Ohio side, they would appear to be the greater of the two, irrespective of the general advantage to the public to be derived from the improvement of the navigation. I do not refer to these for the purpose of presenting an argument in favor of overriding or overlooking the private interests on the Ohio side, but merely as one of the facts belonging to the case. people of Wheeling, so far as I know, have taken no part in any controversy concerning the proposed dam. Yet they are materially interested in the improvement of the main channel adjacent to that city, both immediately above and below it. In low or moderate stages of the water regular daily steam packets ply between Wheeling and the cities below and above. There is a tri-weekly line to Cincinnati; daily lineto Parkersburg, and another to Sunfish, &c., below Wheeling; and to Pittsburg and Steubenville, above, two daily lines; the business of which in low water is now of course regulated during the low-water periods

by the shoalest places they are compelled to pass. Thus a steamer or a barge having an average bearing in the water of 150 by 30 feet, carries 140 tons for every foot of depth she displaces, and an improvement of even 6 inches in the channel depth enables her to carry 70 tons more freight. The advantage of being able to ship even 70 tons more freight on each barge or steamer becomes important when continued through several months of low water, to a city situated as Wheeling is. It is true that the people generally do not pay attention to these points. Yet they are not the less interested. Even the river men themselves are not in the habit of close investigation of the subject, yet it is true that an improvement of one foot in depth along the Ohio navigation is a matter of very great importance, involving material benefit to the commerce of the country, far beyond the sums expended in accomplishing it.

I have recommended the construction of a low dam across the Ohio chute at the head of Wheeling Island, believing that to be the best method of improving the navigation over the shoal places in the main or only channel that is run by river men; but, viewing all the circumstances, my opinion is that for the present it may answer to combine with the erection of a still lower dam dredging of the bars, so as not to reduce the depth, but rather to increase it in the pool at the head of the island.

In order to carry this plan out judiciously and economically there should be some discretion to be exercised respecting the quantity of stone to be put in at the head of the island, and the quantity of dredg ing to be done in the channel.

The estimated quantity required in the dam, and for which a contract exists, is 6,000 cubic yards. A less quantity, say not exceeding 4,000 cubic yards, might be applied to a dam at the head of the island, arranged to suit the case; and dredging, say to the amount of 4,000 cubic yards, made in the channel.

Upon the effect of this work would depend, to some extent, the amount of work required to perfect the channel at Burlington bar, above.

Under the circumstances I think it would be justifiable to authorize the distribution of the 6,000 cubic yards of stone between the two points, namely, the Ohio chute at the head of Wheeling Island, and at Burlington bar, to be arranged to suit the case, with authority to dredge to the extent of not exceeding 4,000 cubic yards in the main channel, on the Virginia side of Wheeling Island.

I think it probable that in this way we may improve these two places without materially injuring any private interests, and without extra cost to the government, bringing them on a par with other points which have already been improved. Coupled with the authority to dredge, and keeping in mind the intimate relation between Burlington bar at the head, and Wheeling Island at the foot of the same point, it would be advantageous to the government if some discretionary power could be given in arranging the amount of riprap and dredging, respectively, at both, to be exercised during the progress of the work. Very respectfully, your obedient servant,

W. MILNOR ROBERTS,
U. S. Civil Engineer, in charge Ohio River Improvement.

Maj. Gen. A. A. HUMPHREYS,

Chief of Engineers United States Army,

Headquarters Corps of Engineers, Washington, D. C.

N 2.

OFFICE OHIO RIVER IMPROVEMENT,

Pittsburg, Pa., February 15, 1869.

GENERAL: In obedience to instructions from Headquarters Engineer Corps, dated October 21, 1868, I respectfully submit the following special report on the subject of the improvement of the Ohio River at Marietta Island. In 1868, at the date of September 9, I had the honor to recommend, among other improvements along the river, the construction of a riprap dam across the Ohio chute at the head of Marietta Island, for the purpose of increasing the depth of water in the main channel, on the Virginia side. Citizens of Marietta having remonstrated against the erection of the dam as proposed at that place, I have, in accordance with my instructions, deferred putting any stone in that part of the river.

The circumstances which led to the present report will more fully appear by referring to letters from this office dated October 16, 1868. Accompanying this report is a chart constructed from new surveys made by Mr. Thomas P. Roberts, assistant United States civil engineer, assisted by Captain George W. Rowley, United States consulting pilot. Proposals were received for furnishing and putting in the riprap stone, and the contract was awarded September 28, 1868.

No work has been authorized excepting quarrying stone, which can be made applicable, in whole or in part, to other points, and especially to Carpenter Bar, if required.

The chart shows very clearly the main features of the case, and will be useful in the determination of the question respecting the proper course to be adopted.

The case is very similar to that at Wheeling Island; at least to a sufficient extent to warrant particular reference to my special report on the proposed improvement at Wheeling Island, dated February 12, 1869, as containing certain general views equally applicable to Marietta Island. In one important respect, the two places are of the same nature; for there is no doubt that, independently of interest at the city of Marietta, the proper method of improving the low-water navigation here is by throwing a riprap dam to turn the water at a three-feet stage (or not exceeding four feet) into the main channel on the left, or Virginia, chute. The fact that no tributary streams of consequence enter on the Virginia side, and that the Little Muskingum River, Duck Creek, (a considerable stream,) and the Big Muskingum River on the Ohio side, in times of freshets contribute large amounts of drift and sand to obstruct the channel, points clearly to the Virginia chute as the natural and best channel, especially in coal-boat stages, when there may be eight or ten feet water in the channel.

But the people of Marietta remonstrate against the building of the proposed dam across the head of the Ohio chute, claiming that it will seriously injure their harbor, and the general interests of the city.

It may be true that a dam put across the Virginia chute, by throwing all the water of the river at and below a four-feet stage into the Ohio chute, would improve the navigation on the Ohio side, and that possibly it might help the harbor at Marietta, to a certain extent; though it is obvious that it would at the same time destroy the low-water channel on the Virginia side, which, for the reason already assigned, may properly be regarded as the main channel of the Ohio River. My judgment, therefore, is decisively adverse to closing the Virginia chute, and in favor of closing the Ohio chute, to the extent indicated, if a dam is to be built across either chute.

The plan of improvement to be carried out at Marietta Island will, to some extent, affect the proposed work for the improvement of the navigation at Carpenter's Bar, one and a half mile above. As suggested by Captain Sanders and Captain Hughes many years ago, the raising of the pool above Marietta Island by means of a dam across one of the chutes, will have the effect of deepening and improving the water at Carpenter's Bar; and owing to the shape of the stream, it is believed that a dam on the Ohio chute would have a better effect, in this respect, than if it were on the Virginia chute.

VIRGINIA CHUTE.

The usual, and ordinarily the best channel is now down the left or Virginia chute. It is shorter, broader, and of the two the more natural. The shoals which now impede navigation on the left chute occur at two points, above Davis's Run, and at Sutton's Run, near each other, at the head of the chute. The bottom is gravel, exempt from sand fillings, such as exist along the Ohio chute, and snags, &c., do not settle in it as they do in the Ohio chute.

OHIO CHUTE.

For the first half mile, from the head down, this chute is the deeper of the two; but snags, &c., thrown out from the Little Muskingum River, which enters above the island, often render the navigation dangerous on that account.

At the end of the first half mile begin the sand-bars, of a shifting, changeable nature, which take off from one foot to two feet or more of the navigable depth elsewhere available at about an eight-feet stage. There have been times, at an eight-feet stage, when boats drawing six feet could not pass Duck Creek. This sand, however, as the river falls, runs off, leaving channels, so that after a long season of what is called "dead low water" this chute sometimes has better water than the other. This occurs, however, when the river trade is also "dead low" or at its minimum, on account of general low water.

Dredging of these sand-bars would be only a temporary remedy, requir ing to be repeated after heavy freshets in the Little Muskingum and Duck Creek.

On the Ohio chute, the channel is very crooked at the foot opposite the city of Marietta, just above the mouth of the Big Muskingum. The jetty, built some years ago by the city, from the foot of the island down stream, was intended to increase the depth and improve the channel and the city harbor, and it has no doubt had some effect.

Dredging has also been resorted to at the city expense, and dredging may temporarily improve the navigation in that vicinity. But the ope rating causes, namely, the general shape of the river, the position of the island and of the city, and the entrance of the three considerable tributaries on that side of the river, may be regarded as permanent, and as always tending during floods to reproduce the same result-sand-bars. My opinion is, therefore, that no work of that character at the lower end of the island, opposite the city of Marietta, can make any permanent material improvement of the general navigation of the Ohio River at Marietta Island, and that consequently it would not be advisable for the government to enter specially upon it. Whatever might be done in that way could only be considered as chiefly a local improvement of the

harbor of Marietta, though incidentally it might temporarily improve the passage for vessels desiring to run the Ohio chute.

The shoals at Marietta Island and at Carpenter's Bar, now afford, in low stages of the river, more than a foot less depth than Petticoat Bar, (one of our improved points, which was formerly much worse,) and nearly a foot less than points up to Wheeling Bar, and down elsewhere on the river. A large profitable freight business can be done at four feet, while with a foot less, the tonnage carried must be reduced one hundred and forty tons on a boat, displacing one hundred and fifty by thirty feet, as shown in my special report on Wheeling Island.

It is not certain that the construction of a low dam on the Ohio chute at the head of Marietta Island will do any serious injury, or any injury to the river business of Marietta. At low water Marietta is now out of the line of the usual channel for steamers, &c., passing along the river, which do not have occasion to stop at that port; and those which touch that port do so when coming down by, rounding to, and passing around the jetty to the wharf boats; while those which touch on their upward passage pass out to the main channel by the same route, as indicated by the red lines on the chart.

At Harmar, on the opposite side of the mouth of the Big Muskingum River, steamers can always land without difficulty when they can run to Marietta, either from above or from below.

Referring to the general remarks contained in my special report on Wheeling Island, dated February 12, 1869, for views having nearly the same bearing upon this case, I would respectfully suggest that we might test the effect of a very low dam on the Ohio chute at the head of Marietta Island, in combination with a dam at Carpenter's Bar, and a small amount of dredging at each place—that is, in the Virginia chute at Marietta Island and at Carpenter's Bar-without increasing the quantity of stone contracted for, but by the addition of, say, three thousand cubic yards of dredging at Marietta Island and two thousand cubic yards of dredging at Carpenter's Bar.

With a little discretionary power authorized to be exercised at these two points, we may succeed in bringing the low-water navigation here on a par with other places we have improved, without material, if any, injury to private interests. And if the people of Marietta become aware that it is our anxious desire to do nothing that will injure their harbor, they will acquiesce in our plans, and perhaps join with us in executing them.

If some discretionary power at this particular locality (Marietta Island) could be made to cover excavation of sand or gravel, or removal of old riprap material that might be found necessary to perfect the general navigation opposite the city of Marietta, in conjunction with efforts of the citizens toward the improvement of the channel, it might prove to be advantageous both to the people of Marietta and to the general navigation interests.

In regard to stone, quarried and delivered along the river bank, and even after it is put into dams, in case of any radical change hereafter in the system of improvement, the material will be conveniently available on any works where such stone may be required.

The bulk of all the work that has been done in improving the lowwater navigation consists of riprap stone, which at a small expense can, whenever it may be necessary, be removed. At present, however, there is no stone quarried, but such as we expect to use during this season. In conclusion, keeping in view all the circumstances of the localities