At Price's Creek and Stott's Mill, an unfinished embankment on the "flats" and in the river has been built, 5,000 feet in length, averaging ten feet in height and twenty feet in width, with slope of one and one-half to one, protected on the outside by a riprap wall for its whole length. This riprap wall, extending 3,000 feet of the distance, averages two and one-half feet in thickness; average height, seven feet. On the inside the embankment is protected by a riprap wall for 800 feet of its length, averaging ten feet in height.

The prism of the canal has been correspondingly excavated by the removal of the earth and work. The whole length of the railroad required to be changed by the location of the canal has been changed, the bridge and culverts built, the ties and iron replaced, and the whole placed in good running order.

The line of public road required to be changed has also been completed and accepted by the supervisors of the county.

From the above we see that the whole amount of embankment completed up to the 30th day of June, 1869, is as follows: 22,200 feet of embankment, averaging ten feet high and twenty-five feet wide at the surface of the water, protected by a riprap wall for 20,000 feet of this distance, averaging two and a half feet thick and seven feet in height above the surface of the ordinary low water; also, 10,380 feet of "toe" or base of riprap wall has been placed in the river, averaging ten feet wide, and two and one-half feet above the surface of ordinary low water, and with an average depth below the surface of two feet, with slope of one to one.

The above is about half of the work necessary to be done in order to complete the embankment wall, and to excavate the prism of the canal for the improvement of the Des Moines Rapids of the Mississippi River.

GENERAL REMARKS.

The work has been done during this year principally by the use of cars and locomotives; the track being laid upon either the embankment or the base of the riprap wall as the case required, and extended as the work progressed. Side and end dumping cars are used for earth, and small plat-cars for stone. The locomotives are small, being built expressly for this purpose, the gauge of the track being four feet.

All things being considered, and due regard being had for the unfavorable weather, the progress made during the year has been satisfactory.

The weather during the spring has, however, been particularly unfavorable for out-door work. A mild, wet winter being followed by a rainy spring, has rendered the movement of earth very difficult, and has interfered considerably with the handling of rock.

The river was unusually high during the months of March, April, and May, and still continues so.

The average force employed during the year was as follows: One superintendent, thirteen foremen, two hundred and forty laborers, twentyone supernumeraries with sixteen teams, one locomotive, fifty earth cars, twenty-seven stone cars, two steam pumps, and three stone boats; average number of working days two hundred and sixty-five, giving for total days' work 72,875 for men, and 4,240 for teams.

The various field operations for the above work were performed for a time by civil engineer assistants O. C. Wetmore and E. Hudson Worrall; then by E. Hudson Worrall alone.

The above gentlemen, with the necessary assistants, were employed

daily during the year in locating the line, laying out and superintending the work, making the necessary measurements, and in estimating and calculating the approximate amounts of work performed each month; all of which was performed in a satisfactory manner under the general supervision of Mr. D. C. Jenné, United States civil engineer, and myself.

The necessary maps and plans for the above work were drawn by civil assistant William Hormuth.

LOCK WORKS.

On Monday, August 17, 1868, Mr. E. Owen, to whom the contract for the labor in the construction of the lower lock was duly awarded, commenced the work by extending a guard-bank of earth across the head of the lock section.

During September, the coffer work for the dam was commenced by running out the timber dam across the foot of the lock section. Meanwhile, the work upon the guard-bank was pushed rapidly ahead. On the 10th of November the entire dam was completed, and united with the earth bank at the head and side, thus entirely inclosing the lock-pit. Pumping was immediately commenced, and the bottom exposed by the 15th of November, but owing to high water, which immediately ensued, it was thought best to flood the dam again, as it was a new one, and not thoroughly settled. The water having fallen off, it was pumped out again November 21st. For the details of this dam, and other points connected with its construction, I would respectfully refer to my monthly report for October, 1868.

On the night of November 30 a break occurred, owing to the high stage of water in the river, the head being at the time nine and a half feet, and the thickness of the dam only ten feet. The leak, however, was promptly stopped, and the entire dam strengthened by timber braces.

The bottom of the river, as exposed by pumping and blasting, shows a coarse, stratified limestone. It was covered with nearly sixteen inches of gravel, shells and sand, but this debris was to be expected, as the dam was built at the foot of the lower chain of the rapids.

Rock excavation was commenced immediately, and carried on with tolerably satisfactory success, the excavated rock being used as a riprap protection for the outside of the main bank, which formed the east side of the dam. On the night of December 30, a break occurred in the east bank; for particulars of which, I respectfully refer to my report for December, 1868.

On the 23d of December, the first stone was dressed, since which time, the dressing of the stone has continued slowly, owing to the difficulty experienced in getting the stone delivered in a sufficiently rapid manner. Owing to the continued high water in the river, the dam was overflowed until the 20th of January, 1869, during which time but little work was done save to continue the dressing of stone, and to fill out with earth between the shore line and lock, with borrowed material. On the 16th of February the dam was again flooded with high water, suspending the work, as in January. The dam was again pumped out, and work resumed by the first of March, and the work pushed forward with tolerable rapidity during the entire month, the weather being favorable. On March 23d, the weather being mild, the work of laying up the outside wall of the pier was commenced, a few stone having been laid December 14, 1868.

On the 3d of April the dam was again flooded by the high stage of water in the river, and the dam has remained overflowed ever since. During this time nothing has been done toward the construction of the lock, except to dress a few stone, and to continue the "filling in" between the shore line and the line of the inside face of the lock walls. The whole amount of work performed by Mr. E. Owen, under his contract for the labor in the construction of the lower lock, up to June 30, 1869, is as follows:

2,880 cubic yards of earth excavated from lock-pit.

4,042 cubic yards of rock excavated from lock-pit.

100

34,718,19% cubic yards of earth embankment from "borrow-pits." 2,150 cubic yards of loose stone in riprap walls from "borrow-pits." 29,271 cubic yards of vertical wall, laid in cement for the pier.

343 cubic yards of stone, dressed for lock walls.

760 feet b. m., white oak timber, prepared and put into the work. 600 pounds of wrought iron, handled and put into the work.

With the above material, the main embankment, forming the outside of the lock section, has been built for four hundred and seventy-five feet in length, with an average width of twenty-five feet, and an average height of thirteen feet above ordinary low water, with slope of one to one and one-quarter, covered on the outside for its entire length and height with a heavy riprap protection. The space between the shore line and the line of the lock wall has been filled in for two-thirds of the distance, with an average height of "fill" of eight feet. The vertical wall is about two hundred feet in length, and ten feet in height. The timber and iron were employed to form a step" against which the foot of the wall rests; the timber being bolted to the rock bottom of the river. The dressed stone is merely prepared, none having as yet been laid.

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The progress made has been satisfactory during the time when the contractor could work, but the work has been much delayed, and considerable time lost by the low timber dam which Mr. Owen constructed. He was advised differently, but from principles of false economy, and through the advice of others, he built only a twelve-foot dam, instead of one fifteen feet high, which was recommended by the engineer in charge. The additional three feet would have prevented all overflows which thus far have taken place; and other work instead of being continually delayed might have progressed regularly and rapidly from the commencement of the work to the present time.

ASSISTANTS.

The field work necessary for the above has been performed by civil assistant O. C. Wetmore, then by civil assistant George A. Keefer, and latterly by civil assistant H. A. Ulffers. The necessary plans, maps, &c., have been drawn by civil assistants G. A. Keefer, William Hormuth, and J. P. Frizell, all of which work has been performed in a satisfactory manner, under the immediate direction of Mr. D. C. Jenné, United States civil engineer, and myself.

STONE.

On the 31st of August, 1868, Mr. Charles E. Tobie, to whom the contract for furnishing the stone for the construction of the lower lock had

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been duly awarded, commenced operations by the opening of a natural quarry, purchased by him near what is known as Ballinger's Run," six miles northeast of Keokuk, and near the line of the Keokuk and St. Paul railway. The months of September, October, November, and a part of December, were expended by Mr. Tobie in opening, stripping, clearing out, and equipping his quarry, and in grading and constructing a line of railroad from his quarry to the Keokuk and St. Paul railway, a distance of about thirteen hundred feet. The first stone was delivered on December 18, 1869, and from that time until May, 1869, the stone was brought down very slowly, and in small quantities.

Much dissatisfaction was felt and expressed at the manner in which Mr. Tobie was fulfilling the terms of his contract. He had delayed the delivery so long, by the dilatory construction of his track, &c., that when he was prepared to deliver the stone the weather interfered very much with the quarrying and the handling of the stone.

No improvement, however, took place during the spring, in consequence of which the cutting and preparing of the stone by the "contractor for the labor on the lower lock" was very much delayed-the quantity delivered being so small as not to keep the cutters employed from day to day.

On the 8th of May, 1869, Mr. Charles E. Tobie formally abandoned his contract entered into the 28th day of September, 1868, to deliver stone for the construction of the lower lock, assigning as a reason for so doing the low prices at which he had agreed to deliver the stone.

The case was reported to the engineer department in Washington, and authority obtained to make a new letting immediately. An advertisement was accordingly placed in six of the leading newspapers throughout the country, naming Monday, May 31, 1869, as the day for opening the bids. Upon a canvass of the bids received it was decided to reject them all, for the reason "that the lowest bidders were not able or willing to give satisfactory evidence of their capacity to deliver the stone in the quantities and within the time required, while all other bidders proposed at too high prices." Authority having been received "to purchase the stone in open market," an agreement was, on the 10th day of June, 1869, entered into with Charles G. Case and F. D. Van Wagenen, to furnish all the stone required for the lower lock, and face and backing stone for the upper and middle locks, so far as the sum (less the necessary contingencies) of $200,000 would pay for the same. For details I would respectfully refer to official letter and report of operations for June, 1869. Up to June 30, 1869, no stone had been delivered by Messrs. Case & Co., the unfavorable weather and necessary preparations preventing.

The whole quantity of stone delivered by Mr. Charles E. Tobie, from the date of his contract to the time that he abandoned the same, was as follows:

331.92 cubic yards of face stone.

335.34 cubic yards of backing stone. 41.63 cubic yards of slope wall stone.

As this was over eight months' work, and the proportion necessary to be delivered in each and every month was eleven hundred and thirtythree cubic yards, it is evident that he had not fulfilled, nor could not fulfill, his contract in any reasonable time.

The stone delivered by Mr. Tobie was a first-rate quality of magnesian limestone, of the "Keokuk group," and is well adapted, and fully complies with the specification as to quality, for the purposes for which it is intended.

Messrs. Case & Co. have purchased the quarry, with its tools, machinery, track, &c., of Mr. Tobie, and are preparing to extend and work it extensively. The appearances are, that that quarry alone will be able to furnish all the stone required.

Messrs. Case & Co. have, however, opened another quarry near Nashville, Lee County, Iowa, from which they propose to obtain stone for the upper lock, situated near Nashville.

The inspection, selection, and measurements of the stone thus far delivered have been made by civil assistant George A. Keefer, under my immediate supervision, until the date of his resignation. Since that time they have been made by Second Lieutenant Joseph E. Griffith, United States Corps of Engineers.

PROBABLE OPERATIONS DURING THE PRESENT WORKING SEASON.

Upon the "section work" steps have been taken to largely increase the amount of work in each month as soon as the water in the river permits. The contractors have been required to increase their appliances, and have now two locomotive engines for hauling earth and stone; some sixty dirt cars and the same number of stone cars, and iron, &c., sufficient to lay a track for the same over four miles in length. About three miles of track is already down and in use.

If favorable weather and a low stage of water ensues for the remainder of the year the whole of the appropriation will be expended by January 1, 1870, and the "section work" about two-thirds finished. The working season for section work is continued throughout the year, as winter interferes but little with the excavation of rock from the prism of the canal, the largest item of the work.

Upon the lock work preparations are already made to push the work with great rapidity, as soon as the stage of the water will permit.

The contractor has all the necessary machinery for doing work rapidly, including steam derricks, and "Burleigh's patent steam drill," for rock drilling, a description of which was given in my report of operations for the month of February, 1869. All the other necessary appliances are on the ground.

It is hoped that by November 15, (the usual close of the working season for such work in this latitude,) work to the amount of $100,000 will be finished, which expenditure will complete all the necessary excavation for the lock, chamber and walls, prepare the masonry, embankment, lay up and complete the pier at the foot of the lock, and probably lay the foundation, and the first course of the lock walls

proper.

The dressing of stone for the pier and lock will be continued as rapidly as the stone is delivered.

The present arrangements for the delivery of stone, it is hoped, will be sufficient to push forward its delivery to the lower, middle, and guard locks, at rapid rates. It is anticipated that by January 1, 1870, about $150,000 worth of stone will be delivered at the various locks.

Preparations are being made to commence cutting the stone for the middle and upper locks, by "days' labor," as soon as Messrs. Case & Co. deliver the stone, and to push the cutting as rapidly as the delivery will allow. The excavation of the lock pits for the middle and upper locks will also be commenced during the present working season.

LAND DAMAGES.

The commission of six freeholders appointed April 28, 1868, by the sheriff of Lee County, Iowa, under the laws of the State, to assess and