Railroad, which connects the coast with Los Angeles. The latter is a city of six or eight thousand inhabitants, surrounded by a fruitful and growing country. The trade of the past year, it should be remembered, is that of a very dry season. The occurrence of droughts every few years is indeed the greatest drawback to this section of the country. San Pedro is a port of delivery. Among the drawings herewith inclosed is a section of the water-way between Deadman's Island and the shore, from which it appears that a rocky reef makes out from both sides, and which is lost in the middle of the channel. Supposititious lines of its outline where not found are given on the section. It is not as yet clearly defined in position and extent, and it will be necessary to make some further observations on this point. It is probable that these observations may develop a necessity to make the entrance to the harbor on the other side of Deadman's Island; but however that may be, the part of the line which it is proposed to build with the present appropriation, viz, XY on the plan, is common to either project. The entrance to the west of Deadman's Island is better than the other, for the reason that the latter would open to the eastward, directly in face of the heavy swells which roll up in the winter storms, which would have a tendency to fill up the mouth of the harbor. This particular point will be the subject of a future report. The observations and survey upon which this report is based were made by Mr. White, civil engineer. They were intended to exhibit the direction of the changes which have taken place since the survey of 1859, to determine the character of the underlying strata, to ascertain the tidal conditions of the harbor, and to determine the practicability of the constructions proposed. He discovers that on the upper portion of the line the substrata are of sand to the depth of at least 15 feet, and that piles may be driven without unusual difficulty. On the lower part of the line near Deadman's Island we find a soft and, at times, hard clay a few feet, generally less than 6, below the surface of the bottom. The same kind of formation extends at least in part (for on this point our observations are not extended) across what is now the shallowest section, from Deadman's Island to the goose-necked spit that makes out from the main shore. The overlying sand in the channel will be easily moved by the ebbing. current. Whether the underlying clay will be worn to the desirable depth by the action of the current can only be satisfactorily known after trial. Our observations indicate with certainty a depth at mean low water of 7 feet at the mouth of the harbor; it is very desirable to have 10 feet. It is possible that this can only be attained by dredging. No estimates for deepening by dredging are included. It will be time enough to esti mate for this when the necessity for it becomes apparent. The safety and preservation of this harbor lie in the preservation of its tidal area, which is mainly made up of the extensive flats heretofore referred to. It is indispensable that they should not be occupied so as to diminish the quantity of water to ebb and flow. Drawings accompanying this report: 1. Coast Survey map of Wilmington Harbor, with certain changes marked thereon. 2. Profile of line proposed from Rattlesnake for Deadman's Island. 3. Profile section of reef between Deadman's Island and the main. 4. Sheet of plans and sections proposed for different constructions. Papers accompanying this report: A. Exhibit of the commerce of Wilmington for the year 1870. B. Sheet of estimates. C. Proposed advertisement for lumber. In view of the possible contingencies in a construction of this kind, and of the disastrous results that might ensue from even a very small deficiency in money, at the last moment, I think good policy requires appropriation beyond the estimates. For these reasons I venture to recommend an additional appropriation of $200,000. Respectfully submitted. G. H. MENDELL, Major of Engineers. P. S.-Advertisement not inclosed; it will be forwarded in a few days. Drawings in a roll mailed the 16th of June, 1871. G. H. M. 559 sacks bread. 76 sacks castor-beans. 19 sacks buckwheat. 32 tons scrap-iron. 103 express freight measurement, equal to 62 tons weight. Total weight 7,050 tons. WILMINGTON OFFICE, LOS ANGELES, CALIFORNIA, JANUARY 1, 1871. Imports during A. D. 1870. 17, 171 tons assorted merchandise and measurement, equal to 10,303 tons weight. 266 tons express freight and measurement, equal to 135 tons weight. 59 wagons and buggies. 280 head sheep. 41 head horses and cattle. 1,096 empty pipes and puncheons. 693 empty barsels. 87 cords wood. 1,250 bales hay, 162 tons. 5,860,005 feet assorted lumber. Total weight 10,600 tons, and 5,860,005 feet assorted lumber. Total tons merchandise received and shipped, 17,550. Weight exclusive of lumber. Vessels arriving, delivering, and receiving freight at this port during the year, 147 steamships and 56 sail-vessels. I certify the foregoing to be a correct statement of exports and imports during the year 1870. Report examined and approved. Cost of 30 cribs, 16 feet high, other dimensions the same, per foot.... .$67 60 per foot. $82 00 8.00 Estimate for 6,700 feet of construction for Wilmington Breakwater. *3,080 feet of construction, No. 1, at $20 per foot. 550 feet of construction, No. 5, at $35 per foot. 1,500 feet of construction, No. 3, at $70 per foot. 1,570 feet of construction, No. 4, at $90 per foot.... Add for contingencies..... Amount of the present appropriation.............. Additional amount required * X to Y, 3,680 feet. 250 00 3,194 65 $31 94 3 06 W 11. Annual report for the breakwater at Wilmington, California, for the year ending the 30th June, 1871. SAN FRANCISCO, CALIFORNIA, July 31, 1871. Under the instructions of the Engineer Department, dated the 22d March, 1871, an examination and partial survey of the harbor of Wilmington was made in the months of April and May. A report and plan for the proposed improvement of the harbor, based upon the results of this examination, was submitted on the 15th June. Under date of the 1st July the project was approved in part by the Chief of Engineers, and orders given to contract for the first division of the line, about 3,630 feet in length. By subsequent telegraphic authority from the Chief of Engineers, dated the 14th July, engagement was made in open market for the timber, to be delivered at San Pedro anchorage. By the same authority, bids have been invited for the construction of this first division. These bids will be opened on the 14th August, and the work advertised is to be completed by the 1st day of March, 1872. After this part of the construction is inaugurated, preparations will be made to construct the remaining portion so far as the available funds will permit. Respectfully submitted. G. H. MENDELL, Major of Engineers. Washington, D. C. The CHIEF OF ENGINEERS, U. S. A., APPENDIX X 1. OFFICE OF WASHINGTON AQUEDUCT, GENERAL: I have the honor to make the following report for the last year concerning the Washington Aqueduct: THE DAM AT GREAT FALLS. The permanent dam extending across the Maryland channel, or from a point near the head of the aqueduct to Conn's Island, remains in excellent condition, and has required no repairs during the year. There was an appropriation of $5,500, available for expenditure during the last fiscal year, for removing the obstructions in the river above the dam, which prevented the free access of the water to the head of the aqueduct. These consist of some low, grassy islands and rocks, and ledges. When I took charge of the aqueduct, in November last, there was a party of workmen engaged at this point, but the water in the river, soon after, had risen so much that the work could no longer be prosecuted to advantage, and I suspended operations at this point till the low water of the present season. On the 15th of July the water had subsided so that work could be resumed, and it will be continued till the appropriation is exhausted, unless high water should interfere. It is believed that the work done and to be done, under the appropria |