raphy of this survey to be used excepting where improvements have been or will be made. (2). Survey made under the direction of Gen. Weitzel in 1879; this is a survey of the channel only. (3). Precise levels which have been brought from sea level to Lake Superior at Marquette by the United States Lake Survey. The work required under your orders was as follows: (1). A primary triangulation connecting the Lake Survey triangulation in the east end of Lake Superior with that in the north end of Lake Huron, with the nec essary base lines and azimuth determinations. (2). Minute hydrography of those points in the channel which have been dredged or otherwise changed since the previous surveys. (3). Topography of that portion of both banks of the river which is conspieuous from the decks of vessels passing through the river. (4). The determination of the latitude, longitude, and azimuth of at least one point in the triangulation. (5). Carrying precise levels westward as far as Bay Mills, for the purpose of making accurate tide-gauge readings at this point. The actual work of this survey was begun in the last days of May. Assistant Engineer Ripley with a party of about 15 men, the tug Myra, and the quarter boat Swallow made a minute survey of the shoals at Sailors Encampment. Mr. Ripley's report is attached herewith: UNITED STATES ENGINEER OFFICE, SIR: The limestone shoal at Sailors Encampment was selected for beginning the hydrographic work of resurvey of St. Marys River, Michigan. Five stations were located for continuing the triangulation of river survey of 1879 from Sailors Encampment to head of Mud Lake. Each station was marked with a piece of limestone about 1 foot square in which was drilled a hole one-half inch in diameter and 3 inches deep. The stones were placed 3 feet under ground and a wooden tripod built and placed in position over each stone. The angles were read with the Piston & Martin theodolite, and each triangle closed within three seconds. The present steamboat channel is on the Canadian side and has three courses from angle above shoal to the can buoy in Mud Lake. A channel was selected on the American side of the river with only one course, and the improvements required will be out of the way of passing boats. Soundings were taken 10 feet apart over an area 400 feet wide and 3,120 feet long, also 30 by 200 feet apart for the full width of the river for a distance of 3,000 feet. Very respectfully, your obedient servant, Mr. E. S. WHEELER, Assistant Engineer, etc. JOSEPH RIPLEY, Assistant Engineer O. B. Wheeler, of the Missouri River Commission, was directed by you to begin the triangulation. Mr. Wheeler reported on the 21st of May, 1892, with 4 assistants from the Missouri River Commission; selected a base line 2 miles in length on Portage avenue. This was measured four times with satisfactory results; he also planned six stations of the triangulation and measured the angles at four of them. Azimuth was observed from a station about 1 mile from the base. Two of Mr. Wheeler's assistants carried a line of precise levels from the masonry of the lock walls to Bay Mills. Mr. Wheeler's report is attached herewith: UNITED STATES ENGINEER OFFICE, Sault Ste. Marie, Mich., June 28, 1892. SIR: Agreeably to the following instructions I reported at your office, at this place, on May 21, 1892. DETROIT, MICH., May 9, 1892. SIR: As soon as relieved from duty on the Missouri River Commission, for temporary service in connection with the resurvey of St. Marys River, Mich., you will proceed to Sault Ste. Marie, Mich., and report for duty to Mr. E. S. Wheeler, assistant engineer in local charge of the public works at that place. The travel indicated is necessary for the public service. Very respectfully, Mr. O. B. WHEELER, O. M. POE, Colonel Corps of Engineers, Bvt. Brig. Gen., U. S, Army. Assistant Engineer. BASE LINE. The first work was the selection of ground suitable for the measurement of a 2mile base line, to be measured with the steel tape by night. The location of this base line was finally on Portage avenue, in this city, and extended from Bingham street nearly to the Little Rapids lining, for the most part of the way, through the center of the street-car track, which track was not then in use. The staking out and measuring of the line was identical with the method used in 1885 under the Missouri River Commission and fully reported in reports for 1885-87. The same "adjuster” as there used was used here, and a standard tape and thermometers belonging to the Commission, together with a standard thermometer 21 inches in length, belonging to Mr. E. S. Wheeler, were used. Three complete measurements were made on the same date (namely, June 1), the first and last measurements agreeing within one-tenth of an inch, the middle one differing by less than one-half inch from either of the others. A 500-foot ste. 1 tape, belonging to the office here, was standardized by measuring a commensurate distance of 1,500 feet measured also with the 300-foot standard tape. A copy of the adjuster and reel of the Commission was made for use with the 500-foot tape. TRIANGULATION STATIONS. The stations of the base line were so located that the triangulation could be carried off on either side of it. The first station off the base was upon the Ashmun street hill, 1 miles from the west base station, and it was selected also as the azimuth station, while the marks (or lantern) was on station "west base." The second station off the base was in Canada, 3 miles from west-base station. The four stations mentioned constitute the first quadrilateral. The fifth and sixth stations are on Sugar Island and Rankins Mountain Canada, respectively, and with the third and fourth mentioned constitute the second quadrilateral. The seventh station is on Larks Ridge, a commanding ridge, about 2 miles southwest from New Fort Brady. All seven stations are described in the notebook and are marked, six with the regulation stone 18 by 18 by 4 inches with a brass center bolt, set 3 feet or more under ground, the sixth being on naked rock, with a half-inch hole drilled in the rock, in which hole is cemented a 20-penny spike with head down. This spike stays the foot of a target. The station is on the highest point of rock within a half-mile radius of the station. At five of the stations portable tripods answer the purposes of a station. At the first station in Canada it was necessary to erect a 21-foot tripod with a target platform at 24 feet above the ground, and on Sugar Island a 57-foot tripod with a 60-foot target platform was necessary, to save the extensive cutting of timber. Assistant Engineer Glen C. Balch successfully supervised the construction of the latter station. Both stations were built of peeled round timber and are models of their kind. PLAN OF TRIANGULATION. A quadrilateral system with a minimum limit of a 30° angle in triangles used in computation is contemplated. This is to be carried on from an 11-mile line between the sixth and seventh stations in connection with the fifth reaching Gros Cap or Iroquois Point, going above, or a point in Canada back of Lake George, going below, looking over Sugar Island from the seventh station. A point south of Waiska Bay should be selected for good conditioned triangles, going above. Also a point south from here about 12 miles on Sand Hill or Stony Ridge between the Meridian and Mackinac roads, going below. Stations of any great height will be required only on the Michigan side to get above the timber. AZIMUTH AND ANGLE READING. The azimuth and angle readings have been made with the Troughton and Simms Theodolite, No. 1, 14-inch limb, fully described in Professional Papers No. 24, Corps of Engineers, U. S. A. Complete azimuth observations on Polaris near and at elongation with the necessary time-star observations have been secured on two nights. These observations were so satisfactory (differing at elongation by only 1.6 seconds) that it was not considered necessary to obtain a third night's observation, especially as the time for angle reading was limited. No star at western elongation was available or it would have been read upon. One half of the observations were from image of the star from an artificial horizon, thus doing away with the reading of the level, a method most highly to be commended. The mark at west base station, was a light through a vertical slit two-tenths of an inch in width. Fogs and clouds cut off the work on many nights. At three of the stations a portable station 6 feet in height has been used, and the readings over the base line were made before 6 a. m., before the street cars were in motion. The reading on first quadrilateral are completed-three of the triangles closing on the first attempt within the primary limit of 3 seconds, the fourth closing outside this limit was reread at one station. The remaining three stations are approximately located. Vertical angles were read at all stations occupied. The readings on angles and azimuth were all made by Assistant Engineer E. B. Wheeler, and recorded by Assistant Engineer Glen C. Balch or myself. PRECISE LEVELS. A line of precise levels was run from B. M. "F." of the Ship Canal to the water gange established at Bay Mills, on a bay which may be considered a part of Lake Superior proper, to find the slope of the St. Marys River above the canal. The report of the assistant engineers who did the work is herewith appended. An approximate result from the few water-gauge readings at Bay Mills indicate a slope of about 0.42 foot. I desire to commend highly all the assistant engineers who aided me in the work. Very respectfully, Mr. E. S. WHEELER, U. S. Assistant Engineer. O. B. WHEELER, UNITED STATES ENGINEER OFFICE, DEAR SIR: Following your instructions a line of precise level was run from B. M. "F" on the northwest corner of the lock to a gauge in Waiska Bay. The length of the main line was 14 miles and 20 yards. The limit of error allowed was 3mm VK, where K represents distance in kilometers. The main line was run in seventeen sections. Of the seventeen, eleven checked on first trial, three were run three times, two were run four times, and one was run five times. In two cases only did the error exeeed 9mm to the mile on the first trial. The adjustment of the bubbles on the rods was tested daily. The adjustments for collimation and inclination were tested morning and evening, except in one or two cases where prevented by rain. The maximum error allowed in collimation was 2mm. The maximum error allowed in inclination was two divisions of the level tube. Four permanent and seventeen temporary bench marks were established and described in the notebooks. The zero of gauge in Waiska Bay was found to be 1.1541 meters 3.78 feet below B. M., "F." Very respectfully, your obedient servants, Mr. O. B. WHEELER, U. S. Assistant Engineer. B. J. THOMAS. A. O. WHEELER. The following instruments for use on this work have been received: 1 Negus chronometer, No. 1524; 2 Troughton & Simms theodolites, Nos. 1 and 3, with 14 inch limbs; 1 Wurdemann zenith telescope, No. 12; 1 Wurdemann transit, No. 1; 1 chronograph, by Bond & Son. All of these instruments were received in good order, except the zenith telescope, which had evidently been injured in transit. All work was stopped on the 30th of June. Assistant Engineer Wheeler returned to the Missouri River Commission, taking with him the base-measuring apparatus. Very respectfully, your obedient servant, Col. O. M. POE, Corps of Engineers, U. S. A. E. S. WHEELER, CCC 2. SURVEY OF WAVERLY SHOAL, LAKE ERIE. REPORT OF MAJ. AMOS STICKNEY, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30, 1892. UNITED STATES ENGINEER OFFICE, Buffalo, N. Y., January 16, 1892. GENERAL: I have the honor to submit the following report upon the survey of Waverly Shoal, Lake Erie. This shoal takes its name from the fact that the propeller Waverly struck upon it September 26, 1890, on voyage from Buffalo, N. Y., to Gladstone, Mich. The vessel was drawing 15 feet of water at the time of striking the shoal, and remained fast until a part of her load was removed, when she got off, reloaded, and proceeded on her way, after a detention of three and a half days. The shoal lies nearly on the line laid out in the Lake Survey chart as the course from Buffalo, N. Y., to Fairport, Ohio. It was not discov ered by the Lake Survey, as the adjacent lines of deep-water soundings passed on either side of it. The general direction of the axis of the shoal is northeast and southwest, and it is about 24 miles from the Buffalo Breakwater light-house, and about 13 miles from the Canadian shore. The 18-foot contour surrounds an area of about 700 feet in length, by from 100 to 200 feet in width. The 16-foot contour surrounds a space about 160 feet in length by 20 to 50 feet in width. The least depth found was 15 feet, though it is probable that there is less depth over some of the bowlders. A buoy was placed on the shoal by the inspector of the tenth light house district in June, 1891. The survey was made by Mr. Ernest Siegesmund, assistant engineer, in the latter part of Septembr, 1891, when the weather was fair and the lake calm. Buoys were anchored along the axis of the shoal and their bearings taken with a theodolite from a base-line measured on the shore and from the Horse Shoe Reef light-house, the Buffalo breakwater light-house, and the south end of the breakwater. Light lines were stretched between the buoys and other lines to small boats anchored at various points. By means of these lines the points of soundings were located with sufficient accuracy. Nearly 1,300 soundings were made, covering the area of less than 24 feet depth, and some lines run out to deeper water. The soundings are reduced to the same plane of reference as those on the chart of the lake survey of 1875. The bottom is rock, with bowlders upon it. Two charts accompany this report, one showing the soundings and the other showing the location of the shoal. The location, as near as it could be determined, is marked in pencil on the original lake survey chart sent to me from your office. The shrinkage of the paper makes it difficult to locate any point on this chart with precision. Very respectfully, your obedient servant, AMOS STICKNEY, Major of Engineers, U. S. A. CCC 3. SURVEY OF SHOALS IN ST. LAWRENCE RIVER, NEW YORK. REPORT OF MAJOR MILTON B. ADAMS, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30, 1892. 1. HASKELL SHOAL. UNITED STATES ENGINEER OFFICE, GENERAL: I have the honor to report the completion of the survey of the St. Lawrence River near Haskell Shoal made by your instructions of August 10, 1891. A chart is transmitted herewith, on which a very dangerous shoal is indicated in red ink, and the least depth on the shoal, 13 feet, is also shown. Two other shoals were found in the course of the survey of the locality with only 26 feet of water where much greater depths are indicated on the chart; they have also been indicated in red ink on the chart herewith. The search NNW. of Haskell Shoal only developed the existence of the one shoal there that has 26 feet of water over it, and the search was made so thoroughly that it seems reasonable to assume that there is no other shoal in that part of the river. The fact that another shoal has been found to exist in the St. Lawrence River almost in exact course of passing steamers, only known to one vessel captain and located by him half a mile below its true position, would seem to emphasize my recommendation of October 10, 1888. (See Report of Chief of Engineers, 1889, page 2463, 1st to 7th lines.) Again the opinion is advanced that the method of sounding used in the survey of the river for the location of its rocky shoals was not sufficiently searching, and that it might well be supplemented by thoroughly dragging all its navigable portions. Very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, M. B. ADAMS, Major of Engineers. Chief of Engineers, U. S. A. REPORT OF MR. F. M. BARSTOW, ASSISTANT ENGINEER. UNITED STATES ENGINEER OFFICE, SIR: I have the honor to submit the following report on the survey of the midchannel shoal recently discovered between Cross-over and Sister Island lights, in the St. Lawrence River, New York: This shoal is not indicated on the sailing charts, and its existence was unknown until a deep-draft vessel recently ran upon it. It is located in a direction S. 26° 30′ W. from Dark Island, N. 80° E. from Cherry Island, and N. 50° W. from Scow Island, about one-fourth of a mile above Haskell Shoal in mid-channel, directly in the usual sailing route of vessels. It is also situated nearly in the same straight line as the three shoals located and described in my report to you dated June 29, 1889, and the reasons given for the removal of those shoals are applicable to this shoal. * Omitted. ENG 92-215 |