The idea advanced in that report, that these shoals, being nearly in the same straight line, might be parts of the same ledge, and "that this ledge may come within 18 feet of the surface in other places not now known," seems to have been verified by the finding of this heretofore unknown shoal. The mid-channel shoal, about one-quarter of a mile below Sister Island, was also surveyed, but its removal does not appear to be as necessary on account of its nearness to a light-house. Very respectfully, your obedient servant, Maj. M. B. ADAMS, Corps of Engineers. F. M. BARSTOW, 2. SHOALS NEAR CROSS-OVER LIGHT. UNITED STATES ENGINEER OFFICE, GENERAL: In compliance with your indorsement dated January 7, 1892 (file-mark, 187, 1892), a survey has been made of four shoals in the St. Lawrence River near Cross-over Light, by Assistant Engineer F. M. Barstow, under my instructions, and I have the honor to transmit herewith a tracing* from the drawing made of the shoals and his report on the survey. The bearings for locating the shoals on the river charts were taken from well-defined bench marks, and Cross-over and Coles light-houses were used in this connection before the recent instructions on the subject were received from the Light House Department. Soundings were made over the shoals to 21-foot depths and their contents calculated, so as to be in readiness to estimate for their removal. In view of the recent movement towards effecting a depth of 20 feet in the upper lake channels, I have the honor to recommend that the excavations of the shoals in the St. Lawrence River be carried to the same depth that may be authorized by Congress for the upper lakes; i. e., as soon as authorized there, then the excavations in the St. Lawrence River be planed and estimated for the same depth. * It is believed that of the several shoals found and sounded Haskell Shoal, the one situated one-fourth of a mile above Haskell Shoal, and the one near Cross-over Light (No. 1), are the most dangerous. Very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, Chief of Engineers, U. S. A. M. B. ADAMS, Major of Engineers. REPORT OF MR. F. M. BARSTOW, ASSISTANT ENGINEER. CEDAR ISLAND, N. Y., June 30, 1892. SIR: I have the honor to submit the following report on the survey of certain shoals in the St. Lawrence River, New York. The survey was made to find, locate, and measure four certain shoals reported to you as having been struck by large vessels navigating these waters during the low water of last fall. They will be designated as Nos. 1, 2, 3, and 4. * Omitted. Shoals Nos. 1 and 2 were found, located, and measured without trouble. Nos. 3 and 4, after most careful and repeated soundings, I am unable to find, but have found two others, Nos. 5 and 6, in the channel that are liable to be struck by large vessels at any time. Shoal No. 1, from its location between Cross-over Light, Whale-back Shoal, and Bay State Shoal in mid-channel, where the channel is narrow and crooked, is one of the most dangerous shoals in this vicinity. I consider its removal to 18 feet below low-water mark necessary to afford safe navigation for large vessels. Shoals Nos. 2 and 5 are in Canadian waters, near a light-house, where the channel is wide. A buoy placed upon them would appear to be sufficient protection. Shoal No. 6 is near the Bay State Shoal, and on side of the channel, so it seems to me that if a buoy were placed upon it the protection would be ample. None of the above-described shoals are indicated on the sailing charts now in use. Their exact location, with soundings taken upon them, are included in the map, field book, and more detailed letter accompanying this report. REPORT OF CAPTAIN WILLIAM L. MARSHALL, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30, 1892. (For letter of transmittal see Appendix J J.) An allotment of $2,000 from the appropriation for the fiscal year ending June 30, 1892, was made and assigned by the Chief of Engineers to this office for a resurvey of the obstructions due to rock reefs, lying off shore between Thirty-fifth street and the south limit of Jackson Park, for the correction of existing maps. A party was organized in April, 1892, and prosecuted work during the remainder of the fiscal year. A base line was measured on the exterior breakwater and a triangulation carried from Diversey street to Calumet Harbor, fixing the shore line. Six angles of this triangulation remain to be measured. Forty-three lines of soundings were made south of Thirty-fifth street and 18 lines north of Thirty-fifth street. The rock obstructions have been located, but more detailed examination will be made of them. The survey will be completed to include the harbors and approaches to Chicago and Calumet harbors, at the expense of the appropriations for these harbors. No further funds required. The report of Assistant Engineer L. M. Mann, herewith, shows in detail the work done. Money statement. April 6, 1892, amount available per letter Chief of Engineers July 1, 1892, balance unexpended.... $2,000.00 1, 172.99 827.01 827.01 REPORT OF MR. L. M. MANN, ASSISTANT ENGINEER. CHICAGO, ILL., June 30, 1892. CAPTAIN: I have the honor to report the work done on the survey of the lake front, Chicago, during the fiscal year ending June 30, 1892. After a few days spent in preparing tools, instruments, etc., and putting steam launch in good condition, actual work in the field was commenced April 25. A base line was measured on the exterior breakwater with a 100-foot steel tape with spring balance attachment. Four measurements resulted in a mean of 5,407.87 feet. Starting from this base a triangulation system was established covering the shore line from Diversey street (north end of Lincoln Park) to Calumet Harbor (South Chicago). The unusual advantage of the three lake cribs and the Auditorium tower as triangulation stations enabled me to evolve a very good system. All points south of the Auditorium to South Chicago form independent triangles with the 4-mile crib and the tower. There are thirty-four triangles in the system, requiring observation of one hundred and two angles. One of the sides, CC', on the easterly breakwater was subsequently measured, making a second base line. Also connections were obtained with the city base line, giving three measured bases in the system. The angles were observed with a transit reading to thirty seconds; four repetitions for each angle were read. Two-thirds of the triangles were closed within four seconds. Total number of angles observed 161 sets; in some cases more than one set was read to close triangle within limits. The triangulation is very nearly complete; six angles are still required to close four triangles. The stadia work, which covers about 16 miles of shore line, is complete. All piers, slips, jetties, revetment, etc., along the shore were located; also prominent streets, buildings, etc. Total number of stadia readings 1,813. Twenty sounding stations were located from Chicago Harbor to Twelfth street, 400 feet apart; and from Twelfth to Seventy-first street 171 sounding stations were located, 200 feet apart. Forty-three lines of soundings were run in lake south of Thirty-fifth street, some of them extending 2 miles from shore. Eleven lines were run east of easterly break water to 25 feet of water. Seven lines were run in Outer Harbor. Total number of soundings=7,833; total number of sounding angles=2,858. A preliminary examination of rocky reefs off Forty-seventh street and between Fifty-sixth and Fifty-eighth streets shows that a very close location of same is essential. Inner reef at Forty-seventh street is about three-fourths of a mile from shore; least sounding taken over same was 3.9 feet at datum. Outer reef at Forty-seventh street is about 2 miles from shore; least sounding taken, 20 feet at datum; but probably there is shoaler water. Outer reef at Fifty-sixth street is about 1 miles from shore; least sounding taken, 11.6 feet at datum. Inner reef about 14 miles from shore; least sounding taken, 9-10 feet at datum. There is over 30 feet of water between these reefs, and also inside of inner reef. Both the months of May and June have been about the rainiest months on record; the extraordinary bad weather has delayed the work to an unusual degree. Very respectfully, your obedient servant, L. M. MANN, CCC 5. SURVEY OF BLACK CREEK SHOAL, LAKE ONTARIO. REPORT OF CAPTAIN DAN C. KINGMAN, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30, 1892. UNITED STATES ENGINEER OFFICE, Oswego N. Y., October 28, 1891. GENERAL: I have the honor to transmit herewith a copy of the report of Assistant Engineer Judson upon an obstruction to navigation which was said to exist in Lake Ontario at a point about 4 miles west of Little Sodus Light, and about 1 mile out from the shore. It will be seen from his report that such an obstruction does exist, but it is of less importance than I was led to believe, because it is only about one-third of a mile from the shore, where the chart calls for 12 feet of water, instead of 1 mile from the shore, where the chart shows a much greater depth. It can hardly be regarded as an obstruction to large vessels, though it might be dangerous to small ones. The original lake survey sheet* is mailed to you to-day in a separate package. I have the honor to be, very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, Captain of Engineers. REPORT OF MR. WILLIAM PIERSON JUDSON, ASSISTANT ENGINEER. UNITED STATES ENGINEER OFFICE, Oswego, N. Y., October 27, 1891. SIR: I have the honor to report that, in compliance with your orders to find, and make a survey of unlocated rocks said to lie in Lake Ontario about 4 miles west of Little Sodus, I left Oswego on the night of October 2 with the steamer Hasleton (which had been hired at $10 per working day or $5 per idle day), ran in to Little Sodus for the night, and, on the morning of the 3d found the shoal in question, with the aid of George Carter, a fisherman, whose partner had reported its existence. The main rock in the shoal has 4 feet depth at present stage of water level (1 foot above extreme low water), and lies one-third mile off the Black Creek outlet, where the lake survey chart shows 12 feet depth. Conspicuous landmarks were identified on the original detail sheet of the lake survey, and a base line was located on the beach by triangulation from these landmarks. From this base line buoys on the shoal were located, checked by sextant angles taken at the buoys. Five deeper rocks near the main and largest one were also located, and the vicinity for one-half mile radius was closely examined to obtain assurance that no shoal spots were overlooked. The only rocks to be noted were five, which were found within 200 feet of the shoalest and largest one. The details are fully given upon the maps* herewith submitted. ANNUAL WATER-LEVEL CURVES OF THE NORTHERN AND NORTHWESTERN LAKES. Tridaily observations were made at Charlotte, N. Y., on Lake Ontario, from July, 1887, to June 30, 1892, and at Oswego, N. Y., from July, 1890, to June 30, 1892. Observations were also made at Cleveland Harbor, Ohio, and at Erie Harbor, Pa., on Lake Erie, from July, 1887, to June 30, 1892; at Milwaukee, Wis., on Lake Michigan, from July, 1887, to June 30, 1892, and daily observations at Escanaba, Mich., on Green Bay, from July, 1887, to June 30, 1892. At the last-named place observations were not made in January, February, March, and *Omitted. April of 1888, nor in January, February, and March of the years 1889, 1890, 1891, and 1892, by reason of ice and snow. Daily observations were made at Sand Beach, Mich., on Lake Huron, and at Sault Ste. Marie and Marquette, Mich., on Lake Superior, from July, 1887, to June 30, 1892. The accompanying tables and plates are continuations of those published in the Annual Report of the Chief of Engineers for 1887, Part III, page 2418. Monthly mean of water levels for the several stations below the planes of reference adopted in 1876. (See plates). 1887. 1888. Stations. June. July. Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May. June. Charlotte. Erie. Cleveland Milwaukee.. Escanaba Sand Beach Marquette Sault Ste. Marie. 3.36 3.19 2.94 2.81 3. 12 2.79 2.66 2.50 2. 13 2.95 2.697 2.690 2.697 2.844 3.143 3.531 3.476 4.030 4.037 4.103 3,640 3.020 3.49 3.63 3.87 3.89 3.69 3.23 2. 63 2.90 3.08 3.46 3.90 3.83 3.80 4.01 3.97 5. 200 4.917 4.98 4.92 4.84 4.71 4. 18 4.31 4.30 3.97 3.945 4.303 4.483 4.331 3.820 3.228 3.231 3.074 3.376 3.90 3.90 3. 468 3.456 3.522 3.466 3.575 3.840 4.76 4.55 4.62 4. 64 4.22 13.98 3.40 3.92 3.85 3.29 3.36 2.56 1.84 3.41 2. 61 1.85 3.854 4.450 4.18 3.59 3.460 |