408 tliE CANADIAN NATURALIST. [Vol. vil. 



results form the yearly balauccs. 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 ihsiU Jive fiet. 

 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 

 diifereut from what we now put it. For the present it is fixed 

 at two and a-half feet below the fiood 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 tem- 

 porally duo 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. AYalworth, Esq., from August to December 1838. Colonel 

 T. B. W. Stockton, who was in charge of the Harbor improve- 

 ments iu 1845-6, caused a full meteorological and water register, 

 to be kept from August 15th, 1845, to September, 1846. A 

 lars:e number of irregular readings were made by the late General 



