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16 MARINE REVIEW. [May 15 WORK OF LAKE SURVEY OFFICIALS. Major W. L. Fisk of Detroit, engineer in charge of the United States Lake Survey, contributes the following interesting account of the work of his office to the 1902 edition of the directory issued by the Ship Masters Association: The duties of the United States Lake Survey in addition to the publi- cation and issue of charts are the making of surveys for keeping these charts corrected to date, the maintaining of a system of water gages ' which give continuous records of the stage of water, and the investigation of the causes affecting the changes in the elevations of the lakes. In connection with its work, the Lake Survey is publishing in colors entirely new charts of many of the harbors upon the great lakes, and expects to continue until all have been similarly charted. In addition the old charts are being brought up to date as rapidly as possible and re- issued in colors, which work will be continued until eventually all charts will be colored. The special value of the new charts is that the blue color at a glance shows all water less than 18 ft. in depth. From Jan. 1, 1901, to April 1, 1902, new charts and revisions of old ones to the total number of twenty-seven have been issued in colors. - A matter of special importance in the use of charts is a knowledge of the prevailing stage of water in the area covered by the chart being used. The Survey publishes early each month in the daily and marine papers the mean stage of each lake, as given by its water-gage records of the pre- vious month. This mean stage compared with the stage to which the soundings on any of the charts are reduced will give the correction to be applied to obtain the prevailing depths of water. To simplify the making of this correction to all new charts, that is those on which the soundings have been reduced to the new standard low-water reference planes--all of which will have a note on them calling attention to the matter--the Sur- vey will inaugurate during the coming season and maintain in the future a system of automatic gage indicators, the readings of which will be the amount, in feet and tenths, to be added to the soundings on these news charts. One of these indicators will eventually be found at all of the prin- cipal harbors and at all important points along the rivers. The standard low-water lake surface or reference planes adopted for the new charts to which all future soundings will be reduced are: Peet above mean sea level. Hoe-a charts of Lake Superior... .wemewrivers 600.00 - ft. Ue a "Lakes Huron and Michigan. .578.00 " eo aes : OP iawe Pile... voces aa 570.00: * eee . Pe Ontario 6... Fes ee 2438.00 " . The standard low-water reference planes for all river charts will be made consistent with those for the lakes which they connect. The object of adopting the above elevations for the standard low-water reference planes is that there will always be more water in the lakes themselves than is shown on the charts. The correction for stage must always be added. The soundings on all new charts issued by the Survey will be referred to these new planes. Those on all old charts will also be reduced to these new planes as rapidly as the work can be accomplished, and will be noted on them when issued. In the last forty-two years the elevations of high and low water for monthly stages are shown for the different lakes in the following table: EXTREME MONTHLY MEAN STAGES OF GREAT LAKES SINCE 1860. HIGH WATER LOW WATER Range Lake Dat Eleva- aie Eleva- | ft. cae tions, ft. tions, ft. Superior........................] Sept., 1869 | 603.63 | Mar., 1880 | 600.19 | 3.44 Michigan and Huron.......| Feb., 1876 | 583.15 | Dec., 1895 | 578.58 | 4.57 Ty alec yelslisics. ds June, 1876 | 574.61 | Nov., 1895 | 570.79 | 3.82 Ontario. 0.25.5;....3°:' Piles May, 1870 | 249.04 | Nov., 1895 | 243.50 | 5.54 The water gages on the different lakes for March, 1902, indicate the following conditions: _ STAGES OF WATER AT OPENING OF NAVIGATION, 1902. Above standard Lake Elevation | low water plane : in feet iirc ncccececsp in vcnnne 601.41. 1.41 a 9 FACOG, 8... ose ces c occ scans 579.28 1.28 Oe 571.04 1.04 Ie. oe. sss, hk Besoin 245.0 2.0 The Lake Survey is continuously sweeping lake areas where shoals are suspected to exist, and masters are requested to communicate. the discovery of any new shoals to Major W..L. Fisk, United States Lake Survey office, Detroit, giving as accurate a description of location as practicable, draught of vessel and date. All such reported. dangers will be examined and charted at the earliest date possible. _ Of course, the object in view in eventually reducing all charts to the new standard low-water planes is to have always at least the depth shown by the chart, and as much more as the reading of the gauge for that local- ity, and the intention has been to take the planes low enough so that the chart user may always have the same thing to do with his gauge reading-- that is add it to the soundings shown. Had higher planes been adopted it would have been necessary to some times add and some times subtract the gauge reading. The five-masted ship Preussen, said to be the largest sailing ship in the world, was launched at Geestemunde this month. She is of 8,000 tons deadweight capacity. The largest sailing vessel heretofore known was the German five-masted ship Petosi. ye ¢ so tth@hhew'tug boat Jolin G. Chandlerthr the | Codtinarcisl thin Phe': ig boat J 'for the Commercial Towboat 'Gd oF Boston 'was gitkesstuly launched tas week froth me i 8 host lley, Speut Co; 'Bath, Me. The tug will cost, when completed, $40,000. CHANGES ON CHICAGO RIVER. Chicago, May 14.--A change, slight in itself, but important to the owners of large vessels on the lakes, has just been made in the north branch of the Chicago river. Incidentally it shows the energy of the management of the Ship Owners Dry Dock Co. and is therefore interest- ing from both points of view. The Ship Owners bid on overhauling the steamer Mauch Chunk, recently; they were told that their bid was good, but that the vessel was too wide to get to their yard on the north branch They replied that they would get her there and were given the contract. She measures 50 ft. beam and has a 9-in. wale strake outside of that, making a total width of 51 ft. 6 in. Indiana street crosses the river at an angle and the abutments and bridge protection are placed at right angles with the street instead of being parallel with the banks of the river. One draw is. narrower than the other, and the widest opening from the piles protecting the abutment to the bridge protection was 49 ft. A survey Alterations (0 -- Indiana Street Bridge Protection. showed that by pulling up the piles and taking off a portion of the pier on the north end an opening of 55 ft. clear could be made. The city had no money with which to do the work and the Ship Owners Dry Dock Co. did it themselves, thus getting the Mauch Chunk to their yard for over- hauling. The vessel is now in the new dry dock. This opens the north branch to vessels of 50 ft. beam and 16 ft. 6 in. draught, something that the owners of such craft. will be glad to hear, as there are numerous coal docks, grain elevators, lumber yards and ore docks on the north branch which have been heretofore obliged to depend upon the smaller vessels. ; eae The accompanying sketch shows the nature of the work. performed on the bridge protection. The dotted lines show that part which was cut off from the west draw and added to the other side, making the protection irregular in shape but permitting the passage of the 50-footers. To draw and replace the. piles, stringers and ties took nearly a week and the company is entitled to considerable credit for the determination and energy displayed. AROUND THE GREAT LAKES. Grain trimmers at South Chicago have advanced the: trimming rate from 65 to 75. cents. per 1,000 bushels. : : The steamer L. C. Smith, built for the United States Transportation Co., of which Capt. W. W. Brown of Cleveland is manager, was launched Wednesday at West Bay City. The new steamer is of the 5,000 ton kind, similar in nearly all respects to several other large freighters which the American company has built of late for Capt. Brown and his associates. On Saturday of this week the Eastern States, first of the big side- wheel steamers for the Detroit and Buffalo line, will be given a trial by the Detroit Ship Building Co., and it is expected that she. will. be in readiness to inaugurate the Detroit-Buffalo service on Monday, June 2. The second steamer, Western States, will be ready about a week later. The new steel passenger steamer Columbia for the Detroit, Belle Isle & Windsor Ferry Co. was launched last Saturday at the Wyandotte yards of the Detroit Ship Building Co. When completed the 'Columbia will be placed on the route between Detroit, Bois Blanc island and Amherstburg. She is 216 ft. in length over all, 200 ft. keel and will carry 3,200 excursion- ists. Gage records of the United States lake survey show the following mean stages of water for April, above mean sea level: Lake Superior, 601.46 ft.; Lakes Huron and Michigan, 579.47 ft.: Lake Erie, 571.58 ft. These stages show Lake Superior to have been 0.20 ft. lower than during same month last year, and 0.01 ft. higher than in April, 1895; Lakes Huron and Michigan were 0.62 ft. lower than during same month last year, and 0.07 ft..lower than during April, 1895; Lake Erie was 0.20 ft. higher than during same month last year, and 0.28 ft. higher than during April, 1895. Capt. R. Jollie of the steamer John Ericsson has made the following suggestion in a letter to the hydrographic office: "TI would suggest that the woods back of the Bernard ranges be removed. There is no time in the forenoon that they can be seen coming down from Point Iroquois until very,near the can buoy at the turn, and it is very hard to locate them. If the woods were cut down it would leave a gap, and steamers coming down could right themselves by steering for it. It would be a great help to everybody. The ranges above mentioned are located above Round island, Waiska bay, Lake Superior, and are a guide out to and from Point Iro- quois. me, + : s DAL LIL J - a -- : fon | Mr. Lewis Nixon' fas" resigned a3' the head' of "Tamithahy Hall and "Says that hereafter he will devote hi§ entire attentiofi'to ship building, © ;