confined to dredging on Swan Island Bar, and the bar at the mouth of the Willamette River, as well as removing snags at each of the abovementioned localities. Surveys of the Willamette Slough and of the mouth of the Willamette River were also made The Willamette River being sufficiently low during August, 1868, to commence dredging, a crew was hired and work resumed August 1, 1868, and continued until December 12, 1868, when work was suspended on account of high water. During this time 18,515 cubic yards of material were removed. The season had been very unfavorable for work; owing to the dense smoke from the woods which were on fire, we were unable to see more than fifty yards from the dredge. The Willamette is also so low during the summer that vessels of much draught must, in passing up and down, occupy the channel in which the dredging is done, and consequently every time a vessel passed we were compelled to stop work, haul out of position, allow them to pass, then get back into position and resume work, all of which caused much delay. While digging we also came into contact with numerous snags imbedded in the sand, whose presence would only be made known by the breaking of some part of the machinery of the dredger owing to the increased strain to which certain parts would be subjected. In December last, when dredging was temporarily sus pended, we had cut a channel over Swan Island Bar which carried fifteen feet of water during low-water stages. Steamers found no difficulty in keeping in the cut, which was well defined by buoys placed at its entrances and angles. The total length of channel cut since the commencement of the work in 1867 at this place has been 3,200 linear feet. On the 25th of February, 1869, the Willamette River was again low enough to resume dredging. We therefore commenced excavating a channel at the mouth of the river, and continued dredging until May 8, 1869, when high water caused a suspension of operations. During this period of work we excavated 12,425 cubic yards of material. The channel cut was 841 feet in length by 100 feet in width by an average of 4 feet in depth, giving a channel carrying 17 feet of water during lowwater stage. There yet remains to be dredged at this place about 300 linear feet, averaging 2 feet in depth, which will probably be completed in August, at an estimated cost of $2,700. Besides dredging, we removed 31 snags which were imbedded in the sand, the largest of which measured 30 feet in length by 9 feet in circumference. The quantity of material removed during the year was 30,940 cubic yards at a cost of $26,414 28, being an average of 85.4 cents per yard. This amount included the repairs of the dredger, the removal of snags, and the surveys of the Willamette Slough and River, which cost $4,861 77. During the latter part of 1868 a survey of the Willamette Slough was made by F. H. West, (one of my assistants,) with a view of ascertaining its adaptability as a ship channel. The survey showed that the slough was not adapted for that purpose on account of its numerous rocky reefs. Maps of the slough, together with a map of the mouth of the river, were sent to the Engineer Department last February. A current chart was also prepared during the early part of 1869, showing the velocity and direction of the current during the winter freshet of 1868-'9 at the mouth of the river. This chart, also a map giving the latest survey of the mouth of the river, by Mr. F. H. West, accompany this report. It was thought that the freshet in the river during January, 1869, would produce certain changes in the bed of the river at its mouth. This actually occurred, and by comparing the last survey (accompanying this report) with those previously made in 1867 and 1868, it will be seen that the current washed out the sand so as to make a channel carrying 12 feet of water in places which previous surveys showed to be almost bare. The June rise of the Willamette River (occasioned by high water in the Columbia) seems to act injuriously to the channel at the mouth of the Willamette, causing a considerable deposit of sand which is only partially removed by the current of the Willamette, after the subsidence of the freshet. The accompanying current chart was made in January of 1869, when the Willamette was only about 10 feet higher than the ordinary low-water stage. This was the greatest height attained during the winter, and was 11 feet lower than the river was during the freshet of December, 1867. The current chart shows that the rate of the current during January, 1869, freshet averaged between two and a half and three miles per hour, which during a heavy freshet would probably be accelerated 33 per cent., the general direction of the current remaining the same. In the June freshets the direction of the current is materially changed. The current then seems to come down the Columbia, passing_between Percy's Island and Nigger Tom, as well as between Nigger Tom and Coon Islands, thence passing back into the Columbia through the slough B between Coon and Laurie's Islands. During this time the Columbia Slough also carries a considerable volume of water, the current of which passes in a northwesterly direction toward Gillingham Point, then separating, a portion passing through the slough B, the other portion takes a southwesterly direction, passing through the Willamette Slough back into the Columbia. The Columbia Slough was formerly used by steamboats in running to Vancouver, but it is now nearly blocked up. I am directed to report on the following eleven points: 1. A survey of Swan Island Bar was made during the year, also of the bar at the mouth of the Willamette River and Willamette Slough. The plan adopted was to dredge Swan Island Bar so as to have 15 feet of water in the channel during the low-water season. Finished the work to that depth. At the mouth of the river we intended to dredge to 17 feet of water over the bar. That work is about three-quarters completed. Items of expense during the year have been as follows: Dredging at Swan Island Bar....... Dredging at mouth of Willamette... Total expended during the year.. $11, 387 31 10, 165 20 4,861 77 26, 414 28 2. It is estimated that the amount that will be required to complete the work at the mouth of the river will be $2,700. To deepen the channel at Swan Island bar to 18 feet of water will probably cost $31,200. It will also probably require a small annual appropriation to keep the channel open to 18 feet of water. 3. The amount that can profitably be expended upon the work during the next fiscal year is $26,500. 4. The collection district is Astoria, Oregon. 5. Portland, Oregon, is the nearest town. 6. The amount of revenue collected is unknown to this office. 7. The amount of commerce to be benefited by the completion of this work is very great. Steamers measuring two thousand tons leave San Francisco weekly for Portland. A large number of sailing vessels also ply between these two ports. 8. No proposals were invited during the year, as the work is not being done by contract, but by the United States, by means of hired labor. 9 and 10. Hence no contracts were made. 11. The following are the amounts of money received and expended on account of the Willamette River work: Cash on hand June 30, 1868..... Received during the year from appropriation for removing obstacles to navigation in Willamette River... For preservation, completion, &c., of rivers and harbors.. Total on hand and received.. On hand June 30, 1869.. The total amount of money appropriated which could be made available for improving the Willamette River was. Total expended to June 30, 1869... Amount available to complete the work.... SURVEYS AND EXAMINATIONS ON PACIFIC COAST. During this fiscal year the only work done under this appropriation was a survey, by Lieutenant W. H. Heuer, United States Engineers, of portions of the Upper Columbia River, known as Homly Rapids and Rock Creek Rapids, with a view of ascertaining the size and position of dangerous sunken rocks on these rapids, with a view to their removal. A few experiments in blasting were made on a submerged rock at John Day Rapids, for the purpose of ascertaining the cost of removal of the numerous rocks in the various rapids of this river. For maps and detail, see reports of my assistant, Lieutenant W. H. Heuer, United States Engineers, forwarded to Engineer Department, November 20, 1868. During the year an allotment of $50,000 was made for the removal of this obstruction. Advertisements were made and proposals invited. Only one proposal was received, which was from Mr. Townsend, of Boston, Massachusetts, and that, proving unsatisfactory, was rejected. Subsequently two allotments, amounting in all to $25,000, were added, making the total amount available for the work $75,000. Mr. A. W. Von Schmidt, a civil engineer, submitted a plan for the removal of the rock, and offered to remove it to a depth of twenty-four feet, mean low water, for $75,000; no money being paid out by the government until the satisfactory completion of the work. Mr. Townsend also presented another proposition. These propositions were submitted to the Chief of Engineers for his decision. At the end of this fiscal year no decision had been made in the matter. PACIFIC RAILROAD. In October, 1868, the Secretary of the Interior appointed me one of the special commissioners to examine and report upon the Central Pacific railroad, and, upon the completion of our report, I was immediately appointed on another commission to examine the Central and Union Pacific railroads, from Sacramento to Omaha. On my arrival at Sacramento, on my way back to my station at San Francisco, I was met by an order to examine at once the Western Pacific railroad, between Sacramento and San José, California. These duties have occupied me during a large portion of the fiscal year, and during the remaining portion much time has been consumed in duty as engineer of the twelfth and thirteenth light-house districts, (Pacific coast.) Respectfully submitted. R. S. WILLIAMSON, Bvt. Lieut. Col. U. S. A., Major of Engineers. Maj. Gen. A. A. HUMPHREYS, Chief of Engineers U. S. A., Washington, D. C. Synopsis of contents of annual report for year ending June 30, 1869. SURVEYS OF MILITARY DEFENSES. The only disbursements under this appropriation have been about $150 per month. The following amounts were received and expended during the fiscal year ending June 30, 1869: This account was closed, by order of the Chief of Engineers, at the end of the first quarter of 1869. It stood as follows: On hand July 1, 1868... Expended during the year.. Balance on hand March 31, 1869.. $651 75 105 08 546 67 which was deposited with the assistant treasurer at San Francisco, California. REMOVING OBSTRUCTIONS TO NAVIGATION IN WILLAMETTE RIVER. During the year surveys were made of the Willamette Slough and of the mouth of the Willamette River Dredging was done at Swan Island Bar, and a channel 3,200 feet long, carrying 15 feet of water at the lowest stage of the river, was completed during this year. This year it is expected to nearly complete Swan Island Bar, excavated to 18 feet of water, at an estimated cost of $31,200. A channel at the mouth of the river was also excavated 841 feet long by 100 feet wide by 4 feet in depth. There yet remains to be dredged at this place about 200 linear feet, which will be completed this year, at an estimated cost of $2,700. Total amount of appropriation for removing obstructions Total amount appropriated and allotted for this work.. Amount available to complete the work... $45, 000 00 21, 000 00 13, 500 00 79,500 00 52,576 26 26, 923 74 SURVEYS AND EXAMINATIONS ON PACIFIC COAST. Under this appropriation Homly and Rock Creek Rapids of the Upper Columbia River were surveyed, and some experimental blasts made on a submerged rock in John Day Rapids, with a view of estimating the cost of removal of dangerous rocks in the various rapids of this river. BLOSSOM ROCK, SAN FRANCISCO HARBOR, CALIFORNIA. No special appropriation has been made for the removal of this rock, but there has been allotted for its removal the following amounts: From the appropriation for the repair, preservation, extension, and completion of public works on rivers and har bors. From the appropriation for rivers and harbors for fiscal year ending June 30, 1869, and June 30, 1870, there has been allotted.... Total amount allotted for the work.... $50,000 00 25, 000 00 75,000 00 |