Great North American Lakes. 79 



T820. But none of the last named travellers, appear to 

 have noticed a similar flux and reflux of the water, in any of 

 the lakes, except that of Michigan ; and have generally ex- 

 pressed opinions, from the limited data which they had ob- 

 tained, that the effect was produced chiefly, if not entirely, by 

 the winds, rather than by the influences of the moon and sun. 



In the autumn of 1826, Capt. Greenleaf Dearborn of the 

 army, informed me, that he had observed a like, but more 

 marked ebb and flow of the waters, in Lake Superior. He 

 had been stationed, for two years, at the Sault de St. Marie» 

 and gave such indisputable evidence, of the existence of a 

 great and regular tide in that immense lake, that I became 

 deeply interested in the subject, and determined to institute 

 an inquiry, which, I was in hopes, would have resulted in the 

 acquisition of more particular and extensive information ; 

 and as I had often heard it remarked, that there was a rise 

 and fall of the water, of two or three feet, in some of the 

 great lakes, during periods of from three to seven years, I en- 

 deavored, at the same time, to obtain positive data as to this 

 current report. At the close of the year 1826, and early in 

 1827, letters were written to several gentlemen, who I pre- 

 sumed might furnish the results of their own observations, 

 or of others who had resided on the borders of the lakes, and 

 with whom they had been in habits of intimacy. Very inter- 

 esting answers were kindly returned to the queries submitted, 

 by Maj. Storrow, Doct. Lovell, surgeon general of the army, 

 and Captains Whiting and Dearborn, but so few and limited 

 have been the attempts, to ascertain the character, extent 

 and periods of the fluctuations of the level of the water, in 

 any of the lakes, that theoretical speculations, as to the cause, 

 would be premature ; and I have concluded, that I could not 

 better subserve the interests of science, than by transmitting 

 to you, for publication in the American Journal, such infor- 

 mation as I had procured, as it may tend to excite investiga- 

 tion, and superinduce more numerous, accurate and contin- 

 ued observations, than have hitherto been made, for the solu- 

 tion of this problem. 



It is not sufficiently certain, that tides may not be produced 

 in the great chain of lakes, in the same manner they are in 

 the ocean. The following theory of the distinguished Doct. 

 Young, which has been sanctioned by the scientific, for more 

 than twenty years, not only presumes the possible existence 

 of such tides, but furnishes the means of demonstrating that 

 such is the fact, in deep and broad lakes. 



