results form the yearly balances. If the annual fall of water equalised for the entire Lake Country is above the average, there must be an accumulation. If it is less, there will be a depression. When several years are on the side of wet, the rise continues each year showing an increase of height, as it was from 1819 to 1838; amounting to a little more than five feet. Then a rapid change of the seasons occurred, on the side of drier and more evaporative weather. From 1838 to 1841 inclusive, taking the mean water of each year as a plane of comparison, the water fell 4.15 feet. Since 1819 the water has not been permanently as low; but in 1846 it reached a point 4.77 below 1838, or within five inches of extreme low water; as at present known. There are, however, causes in operation that increase the suddenness of the discharge of water from the Lake tributaries into the Lakes and thus tend to increase the height of water. If these excessive discharges should occur when other circumstances are in favor of high water, the lakes will reach a higher stage than has been yet known. Thus it it may occur, that the range between high and low water may be greater than five feet, and the mean level be somewhat different from what we now put it. For the present it is fixed at two and a-half feet below the flood of 1838; which is five hundred and sixty-four feet above mean tide water at Albany, New York. The city directrix or zero of city surveys, was fixed by an ordinance in 1854 at high water mark of June, 1838, which is also made the zero of most of the railway surveys in Ohio. In a note there will be found some of the bench marks established by the City Engineers. These two classes of fluctuations, the annual and the general or secular, must not be confounded with those which are temporally due to storms, variation of atmospheric pressure, and aerial movements or undulations; not yet fully understood, and which I have called "transient oscillations.” Prior to 1859, there were daily registers kept at Cleveland for only two short periods. The first was by George C. Davies, under the direction of the Government Harbor Agent, Ashbel W. Walworth, Esq., from August to December 1838. Colonel T. B. W. Stockton, who was in charge of the Harbor improvements in 1845-6, caused a full meteorological and water register, to be kept from August 15th, 1845, to September, 1846. A large number of irregular readings were made by the late General Ahaz Merchant, I. N. Pillsbury, late City Engineer, Captain B. Stanard and myself, extending from 1834 to 1859, but not at regular hours, nor on consecutive days. The labor is too great for any person to undertake who is not employed for that purpose. In addition to the observations made at Detroit, by the first Geological Survey and by A. E. Hathan, City Engineer, and Jacob Houghton as Engineer of the Water Works, there have been a large number of readings at Black Rock, and at Buffalo, New York, by the Engineers of the Erie Canal. All these can be brought together and thus made to supplement each other. On the supposition that the Lake in calm weather is approximately level, readings made here and at either of the other places at the same time, may be regarded as representing one plane surface. The Detroit gauge is higher than the others by the descent of the river from there to Lake Erie; but the fluctuations are in consonance with those in the Lake, and therefore may be used. After the water tables at Detroit, Cleveland and Buffalo were made out, it appeared that they had some periods of time in common, and thus they could be brought together as one series of observations, good for the entire Lake. For instance, Mr. John Lothrop, an intelligent engineer in the employ of the State of New York, and myself, made observations for the month of July 1851. The average for that month at Cleveland was 1.96 feet, and at Buffalo 9.46 feet above the metre sill of the guard lock. zero. This gives for the Cleveland zero 11.42 feet above the Buffalo At Detroit Mr. Hathan used the base of the tower of Water Works, and measured downwards from that as zero. By comparing his tables with ours and disregarding the descent of the river, I find his zero to be 3.43 feet above ours, or 14.85 above bottom of Canal at Buffalo. In this manner, I have combined all the reliable monthly averages from 1838 to 1853, at the three ports of Buffalo, Cleveland and Detroit, into one expression in the form of curves, as shown in the engraving on the next page. These results and those which may follow from the Government observations are of great importance to the commercial interests of this Lake. Harbors, piers and channels to be permanent must be constructed with reference to low water. Prior to 1854 the chief of the Topographical Corps, under whose direction the surveys of the Lakes were conducted, paid no attention to these fluctuations. One of the consequences of this oversight has been the reconstruction of the Canal at the Sault Ste. Maric. Locks that were built to pass vessels of twelve feet draft, would at times allow of only nine feet. Soundings were referred to no fixed planc. There may be a difference of five feet, between the early soundings on the lakes and the true depth of water. Private docks and warehouses are also affected. The proper plane of reference is that of mean water level. Below this, arrangements should be made for a depression of two feet six inches for extreme low water, which may temporarily reach three feet. There is another cause of depression which is having its effect continually; but is so small as to be imperceptible during the life of a generation. This is the perpetual wearing away of the channel at the outlet. On the Upper Lakes there are evidences of a perceptible lowering of the outlets, since they assumed their present general level; but on Lake Erie it is not yet perceptible. It does not probably exceed an inch in a century. According to tradition among the French residents of Detroit, which was settled in 1701, there has not been since that time as high water as that of 1838. A conjunction of circumstances such as to cause a state of extreme depression, or extreme high water, will occur only at long intervals, owing to the extent of country drained by the lakes. The tables show that there is no period of seven years, or a multiple of seven. This is a popular belief derived from Indians, by the early settlers, which has not yet entirely died away, but which never had the support of observations. Mean annual fnctuation, result of sixteen years' observations .... 1 ft. 11 in. Difference of highest and lowest months within the year. Greatest temporary difference between 1819 and 1838.... 6" 11" Bench marks in the city of Cleveland, referring to city zero, which is the line of high water of Lake Erie in June, 1838, 566.50 feet above mean tide water at Albany, N. York:* 1. Surface of stone work, East Pier, 400 ft. from the south end (now lost). ...... 2. Capt. Meade's U. S. Top. Engineers, 1859, on a pile east of No. 1 3. N. E. corner of base water table, Hotel corner of Main and River streets, west side. City Engineer Strong, 1874..... 4. N. E. corner Myers' Stove Works, River street, west side. Asst. Engineer Wheeler, U. S. Survey, 1874 5. Door sill, S. west corner of Engine House, C. C. & C. R. Road, Front street. I. N. Pillsbury, City Engineer, 1854 ... 6. Coping of west wing wall of canal lock at the Cuyahoga river. R. E. Howe, State Engineer, 1838. 7. First course of masonry, base of Light House, 3 ft. above ground, Water street; projection of 0.200 ft. over the course below. Asst. Wheeler, Lake Survey, 1874 ...... 8. N. E. corner of base of Perry Monument. C. G. Force, Asst. City Engineer, 1874..... 9. Mitre sill of guard lock, Erie canal, Buffalo State Engineer, John Lothrop, 1854..... 2.00 feet A. 10. Base of water works tower, Detroit. A. E. Hathan, City Engiueer, 1854... 3.430 66 A. Plane of Soundings at Cleveland: U. States Assistant Engineer, Geo. Fell-fall of 1873.... City Engineer, Chas. Strong, Feb. 1873. Col. T. B. W. Stockton, Harbor Agent, April, 1846.... Lowest water, monthly mean, March, 1846. Stockton's daily register.... Average low water at Cleveland, Detroit and Buffalo, 1846..... Extreme low water-by monthly average-1846...... Stage of water 2,500 feet B. * Mr. Jos. T. Gardner, Geographer, Washington, D.C., has in connection with the U. S. Coast Survey revised the elevations of the Lake region and the Mississippi valley, by whom mean tide at Albany is 4.84 feet above mean tide at New York. |