Mr. A. W. Von Schmidt has made an offer to remove Blossom Rock, to the depth of 24 feet below mean low water, for $75,000; which proposal was submitted to the Chief of Engineers for decision, but at the end of the fiscal year the matter was undecided. V 1. SAN FRANCISCO, CAL., November 7, 1868. COLONEL: I have the honor to report that, in accordance with your instructions, I sailed from this place for Oregon on July 24, 1868, for the purpose of organizing parties for the continuance of work in the Willamette and Upper Columbia Rivers. Parties were organized immediately after my arrival at Portland, Oregon, and the dredging apparatus was soon set at work at Swan Island Bar, in the Willamette River. As the surveying schooner for the survey of the Upper Columbia River needed extensive repairs, those repairs were not completed until August 21. The succeeding day we sailed up the river and arrived at Homly Rapids on August 26, and began the survey next day at HOMLY RAPIDS. This rapid is in the Upper Columbia River, about one hundred and thirty miles above the Dalles, and about five miles below the mouth of Snake River. The nearest town is Wallula, (old Fort Walla-Walla,) Washington Territory, which is about four miles below the rapid. The river at Homly Rapids is three thousand three hundred feet wide, and contains numerous gravel bars. The current is rapid and varies with the stage of water in the river, being very much stronger in high than in low water. While we were at this rapid the rate of the current was six miles per hour, but during high-water season I am informed that it will average at least ten miles an hour; but during the lowest water the rate will probably not exceed five miles an hour. The soundings on the map indicate the depth of water at low-water stage, expressed in feet. The only part of the rapid where very careful soundings were made was between the two gravel bars, (see map,) as this was the only place in the rapid where there was much hope of being able to improve the navigation. The whole rapid was examined by me in a small boat, but with the exception of the place just mentioned, where the soundings show for themselves, the water was so shoal and rocks so plentiful that it was almost useless to devote much time to its survey; these shoals are indicated on the map by dotted lines. The whole of the river at this place is shoal, its bed is comparatively flat, covered with boulders, varying in size from an inch to several feet in diameter, and occasionally a portion of the bed rock (basalt) crops out and is visible under the water. The obstructions to be removed are ledges or portions of reefs of basaltic rock. Formerly there were large boulders in the river here, that interfered with steamboat navigation, but they were removed by private enterprise. The ledges which would require removal here are indicated on the map by dotted red lines, and measure one thousand one hundred and ninety-two cubic yards. One of the advantages that would result from improving this rapid would be that boats would be enabled to reach Lewiston, Idaho, on Snake River, a few weeks earlier in the season than at present. (See letter of J. C. Ainsworth, in Report of Chief of Engineers for 1867, page 509.) According to that letter it would also enable boats to reach Priest's Rapids, in the Columbia; but, as there is no settlement at or near Priest's Rapids, I see no necessity of boats going there. ROCK CREEK RAPIDS. The next rapid surveyed is known as Rock Creek Rapids, situated in the Upper Columbia River, about forty-two miles above the Dalles. The shores on both sides of the river are rocky, and, within a mile of the river bank, the hills rise to a height of over a thousand feet. One thousand and eighty-two soundings were made in and near the channel of this rapid, and although many rocks were found, there were none that offered any serious obstacle to navigation. There are, therefore, no rocks recommended for removal in this rapid. The rapid is three-quarters of a mile in length, and in this distance has a fall of 8.34 feet; its current varies from five to ten miles an hour; during an ordinary stage of the river the current will not exceed six miles an hour, while immediately above and below the rapid, the current runs at the rate of one mile an hour. BLASTING EXPERIMENTS. Blasting experiments were made on a submerged rock in John Day Rapids, with a view of estimating the cost of removal of the various rocks in the river, but the results were unsatisfactory. A frame (see sketch of frame appended) was placed on "John Day Rock." It was thought advisable to put one or two drill holes in the rock, then insert some explosive compound, throw down as much rock as possible, by firing the blast, and thus make an estimate of the cost of removal of this rock. The drills used were of various shapes; some were plain, others curved like the letter S, while still others had a cross-section like this +, known as double bits or diamond drills; each of these drills was made so as to drill a three-inch hole, and were tried, but it was found that the plain bit would continually wedge in the hole; the curved bit (S) would chip off almost immediately after being inserted in the hole; therefore, the double bits or diamond drills were the only ones that could be used that promised any good results. With this bit we could drill a very round hole; it required three men to handle the drill, and the method adopted is called the churning process. The average depth of hole drilled per day, when work could actually be done, was twelve inches; each drill would require sharpening for every three inches of hole bored. The rock was so hard in places that the drill in striking against the rock would sometimes rebound three inches, and sound as though it were striking against an anvil. Considerable time was lost in preparing the drill-holes by not having a blacksmith on hand, but none could be obtained in that section of country; the drills had, therefore, to be sent to the Dalles (distant about thirty miles) to be dressed, and we were obliged to await their return. Eventually, after considerable trouble, we succeeded in getting the hole four feet deep, and placed in it a tin canister, containing four pounds of gunpowder, then endeavored to explode it by means of a Bickford fuse, but owing to some defect in the fuse, it failed to ignite the charge; the canister was jammed into the hole so tight that it could not be withdrawn. A cartridge was then prepared containing two pounds of giant powder and inserted in the hole (on top of the canister containing the ordinary powder) and exploded; the result was that 43.6 cubic feet of rock was removed. As it would have taken many weeks more to have drilled another hole in the rock, we concluded to see what effect a surface blast would produce; a cartridge, containing five pounds of giant powder, was then placed under water, and under an overhanging shelf of the rock, in about six feet of water, and exploded, but without effect. The experiments just made were of but little assistance in enabling me to make a fair estimate of the cost of removal of the rock. My impression is that the rocks can be removed by drilling holes in them, then inserting explosive material and firing the charge. I think, too, that that is the only practicable way of doing the work, but for such a hard rock a three-inch drill is too large; drill one inch in diameter would be large enough, for with a one-inch drill a man ought to be able to drill two feet a day, whereas with a three-inch drill three men can only drill one foot per day; moreover, as the drill-holes will in no case be over seven feet in depth, a one-inch hole is better adapted to that depth than is a three-inch hole. I would also suggest that giant powder be used instead of ordinary blasting powder. The following is the data obtained from the recent experiment on which to base estimates for the removal of the rock: Amount of rock removed; 43.6 cubic feet, cost per cubic yard, $81 25. Owing to my inexperience in blasting, the above cost per cubic yard was very great, and should not be considered as anything like a fair estimate of the cost per cubic yard for removing the various rocks in the river. The subjoined estimate I consider more nearly correct. $10,967 in gold=$15,667 14 currency, rating legal-tender notes at 70 cents; which would make the cost per cubic yard for removing the rock at John Day rapids = $18 09; to which should be added $10 per yard for removing the debris, making a total of $28 09 per cubic yard. The various rocks in the rapids to be removed will measure 5,934 cubic yards, which at a cost of $28 09 per cubic yard would require $166,686 06 to be appropriated for this purpose. Very respectfully, your obedient servant, Lieut. Col. R. S. WILLIAMSON, U. S. A., W. H. HEUER, Lieutenant of Engineers. Major of Engineers. Description of frame for submarine blasting. Each of the four legs is a cast-iron gas pipe four inches in diameter, into the bottom of which a conical piece of iron is fitted to prevent the legs from slipping. In each of the four angles of the wood-work of the frame is an iron cylinder through which the legs can slide freely; each leg is firmly held, (when in position,) by means of a set screw attached to the cylinder. The diagonal braces are ordinary one-inch gas pipes and are fastened in iron bands, which slide up and down each leg and which can also be clamped by set screws; each leg has two of these bands, and each brace runs from the bottom band of one leg to the top band of the adjacent leg. The frame weighs about twelve hundred pounds, is stable and durable, offers but little resistance to the current, and the platform from which the drilling is done can always be levelled irrespective of the shape of the rock on which it may be placed. It was used this year in John Day rapid of the Columbia river, where the rate of the current was seven miles an hour, and was found to work very well. Respectfully submitted. Bvt. Lieut. Col. R. S. WILLIAMSON, W. H. HEUER, Lieutenant of Engineers. Major of Engineers. SAN FRANCISCO, CAL., November 20, 1868. GENERAL: I have the honor to forward herewith a report, with maps, of the survey made by Lieutenant Heuer, United States engineers, of Homly and Rock Creek rapids of the Upper Columbia River. These surveys complete the series contemplated in the act making appropriation for the survey and examination of that portion of the river. Some experimental blasts have also been made with a view to furnish data for an estimate for removing the obstructions. As the expense of such experiments is considerable, and as they are of no ultimate benefit unless an appropriation is made for actually removing the rocks, I did not consider it advisible to make further expenditures for that purpose. If the rocks are to be removed, the amount that can be profitably expended towards that object during the next fiscal year is estimated to be $50,000. As the work of surveying the obstructions on the Upper Columbia River is completed, and as, after this month, no further expenditures under that appropriation are anticipated, I respectfully submit the following as the amount already received and expended since the first of July last: On hand July 1, 1868.... Received during the fiscal year.. Total amount on hand and received.... Expended and to be expended during the year . On hand December 1, 1868... $10,165 16 10, 165 16 4,478 62 5,686 54 Very respectfully, your obedient servant, R. S. WILLIAMSON, Bvt. Lieut. Col. U. S. A., Major of Engineers. Gen. A. A. HUMPHREYS, Chief of Engineers United States Army. V 1a. SAN FRANCISCO, October 16, 1869. GENERAL: I have the honor to transmit herewith a report of Lieutenant W. H. Heuer, who has recently returned from the Willamette River, by my order, in order that he may be available to conduct the proposed survey at San Diego Harbor, very important duties, as engineer of lights on the coast, preventing my conducting it in person. The views expressed in Lieutenant Heuer's report are approved by me, and I respectfully request that the sum of $31,000 be appropriated for operations in the next fiscal year, which sum, it is supposed, will complete the work on Swan Island Bar, and keep open the one at the mouth of the river during that year. I have the honor to be, very respectfully, your obedient servant, R. S. WILLIAMSON, Bvt. Lieut. Col. U. S. A., Maj. of Engineers. Gen. A. A. HUMPHREYS, SAN FRANCISCO, CAL., October 16, 1869. COLONEL: I have the honor to report that, in accordance with your instructions, I went to Portland, Oregon, on the steamer which sailed from here September 29, 1869. Having arrived at Portland I went on board the dredger which was busily engaged in dredging at the lower end of Swan Island Bar. Previous to recommencing work at this point this summer we had excavated a channel, which carried fifteen feet of water, entirely across the bar. In your annual report of operations of the Willamette River it was stated that "this year it is expected to nearly complete Swan Island Bar to eighteen feet of water, at an estimated cost of $31,200." This estimate, both as to time and cost, was made on the supposition that the cost of dredging, at a depth between fifteen and eighteen feet, would not vary very materially from what the previous dredging had cost; but, upon resuming work at Swan Island, (since the annual report referred to was submitted,) we find that |