210 On the Tides in the great North American Lakes. 



though somewhat modified in their height and recurrence by winds, 

 and other terrestrial agents, are, nevertheless, so regular in their flux 

 and reflux, as to show a constant and inseparable connexion with the 

 movements of the moon and sun. We presume the only question here 

 to be, whether the apparent tides in the lakes exhibit any character- 

 istics of a similar connexion ; tha:t there is a frequent rise and fall in 

 the level of the lake waters is beyond dispute. And it is as certain, 

 that these fluctuations, in some places, appear to be as independent of 

 atmospheric, as of lunar control. But, while we are unable to refer 

 them to. one cause, it does not follow that they must be assigned to 

 the other. Gov. Cass did not annex to his observations any note of 

 the "moon's southings" at the time. If there were the remotest 

 probability that such a reference could be useful, it might still be 

 done. But the utter discrepancy between all lunations and the ebbs 

 and floods noted down in his table, renders such a task supereroga- 

 tory. If the table be examined throughout, there will probably not 

 be found an instance, where the time of high water tallies with the 

 moon's southing, admitting the usual retardation. Even if there 

 were several such instances, they ought to be regarded as fortuitous 

 coincidences, as nothing but a prevailing concurrence would authorize 

 us to link them together as cause and effect. 



It may be well to draw a few facts from the table, to show the ir- 

 regularity and caprice of the times of high water. To avoid any ap- 

 pearance of making partial selections, we begin at the first dates.. 

 July 15th, it was high water at i past 7, P. M. the 16th, at i past 

 8, P. M. the 17th, at 8, A. M. the 18th, at noon, and again at| past 

 7, P. M. the 19th, at 9, A. M. the 20th, at 4, P. M. the 21st, at | 

 past 7, P. M. the ?2d, at 4, P. M. the 23d, at 4, P. M. the 24th, at 

 4, P. M. the 25th, at | past 7, P. M. Making allowance for a part 

 of the night, during which no observations were made, the intervals 

 would still appear without the slightest accordance with planetary at- 

 traction. They rather, so far as these instances go, evince some- 

 thing like a diurnal variation, arising from some local atmospheric 

 habitude. Upon reference, however, to the course of the wind, as 

 stated to have prevailed during those days, we do not find any such 

 alternations of its currents, as would sustain such an opinion. 



It will be seen, as we have before remarked, that the changes of 

 elevation are independent of the course of the winds; that the fluc- 

 tuations continue, notwithstanding the winds.remain the same. Gov. 

 Cass suggests a reason why the Fox River should fall, even while 



