On the Tides in the great JVorth American Lakes. 213 



these influences to act without disturbance from other causes, nice 

 observations, at different points, would doubtless detect a small lunar 

 tide. But such a halcyon lapse of time is improbable, if not impos- 

 sible. And as long as shifting winds, or even breezes, are continu- 

 ally varying the surface of the waters, they will so interfere with 

 these delicate tumefactions caused by the moon, as wholly to disguise 

 or overpower them. 



Reasoning from our knowledge of the great inland waters of the 

 other hemisphere, we should take it for granted, that the North Amer- 

 ican Lakes have no sensible tide. The Caspian, Black and Baltic 

 seas, are said to have none ; and even the Mediterranean is indebted 

 to the sharpsightedness of modern times, for the development of such 

 a phenomenon on her wide spread bosom. 



As General Dearborn has thrown out a hint respecting the sup- 

 posed tide in Lake Superior, I have obtained a communication from 

 H. R. Schoolcraft, Esq. on that subject. His long residence at the 

 foot of that lake, combined with his enlightened powers of observa- 

 tion, and habitual use of them in the furtherance of scientific objects^ 

 give much weight to his opinions. Gov. Cass, whose opportunities 

 have been great, not only to see himself, but to collect the opinions 

 of others, is satisfied that there is no sensible lunar tides on the lakes* 



" Detroit, January 19thj 1831. 



Maj. Henry Whiting. — Dear Sir, — ^The idea of the existence 

 of a tide in our lakes, caused by lunar attraction, appears to have 

 originated in those changes in the level of the waters, which are pro- 

 duced by atmospheric phenomena. These changes were observed 

 at a very early day, and they have continued to be observed, by 

 travellers' and by the resident population, down to our own times* 

 The attention you formerly bestowed upon the subject, induces me 

 to hope that you will resume your observations, and give the result 

 of thbm to the public, in such a form as may enable others to 

 judge of these phenomena, and the particulars wherein they dif- 

 fer — if, as I believe, they do indeed differ, from the ordinary, and 

 from any known appearances of oceanic tide. I know not that your 

 own observations will go the length of these conclusions, or that the 

 conclusions themselves are based on remarks, which can be fully 

 brought to mind. But I will endeavor to put you in possession of 

 some facts bearing on the subject. 



Vol. XXL— No. 2. 28 



