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Major Lachlan on the Rise and Fall of the Lakes. 65 
that the rise on this occasion was wholly owing to fortuitous 
circumstances, and not to any regular established law of nature; 
and that its being greater than usual was more imaginary than 
real; and he formed this opinion from the circumstance that 
when the Lake had risen to its unusual height in 1795, he had 
questioned some of the oldest people as to the comparative height 
of the water on this and former occasions, when they affirmed 
term risen periodically above their usual level.* 
hat Mr. Carver relates concerning this subject rather tends to 
confirm the opinion that the waters of the Lake do rise periodi- 
cally. “I had like to have omitted (he says) a very extraordinary 
circumstance relative to these Straits (of Michilimackinae, be- 
tween Lakes Michigan and Huron). According to observations 
made by the French, whilst they were in possession of the fort 
there, although there is no diurnal flood or ebb to be perceived in 
these waters, yet from an exact attention to their state a_periodi- 
cal alteration has been discovered. It was observed that they 
arose by gradual but almost imperceptible degrees till they had 
reached the height of three feet. This was accomplished in 
seven and a half years; and in the same space of time they as 
gently decreased, till they had reached their former situation. So 
that in fifteen years they had completed their inexplicable revolu- 
tion. At the time I was there, the truth of these observations 
could not be confirmed by the English, as they had then been only 
a few years in possession of the fort, but they all agreed that some 
alteration in the limits of the Straits was apparent.” “It is to-be 
lamented (added Mr. Weld jndiciously) that succeeding years have 
not thrown more light on this subject. . . . A long series of 
observations are neccessary to determine positively whether the 
waters of the Lakes do or do not rise and fall periodically. It is 
well known, for instance, that in wet seasons they rise much 
above the ordinary level, and that in very dry seasons they sink 
considerably below it; a close attention, therefore, ought to be 
Paid to the quantity of rain that falls, and to evaporation ; and it 
ought to be ascertained in what degree the height of the Lake is 
_* The destruction of these trees would depend more on the length of time bose 
were inundated, than on the mere fact of their having been temporarily flooded. 
Szconp Serius, Vol, XIX, No. 55.—Jan., 1855. 9 
