3 
Major Lachlan on the Rise and Fall of the Lakes. 49 
ticular year; and that though the rise and fall in the different 
Lakes may, under ordinary circumstances, be generally simul- 
taneous, it does not follow that such will always be the case; or 
in other words, that there may sometimes be a rise for a season, 
or part of a season, in one Lake, altogether independent of the 
others, arising from temporary obstructions at its outlet—a con- 
clusion which I have arrived at, after much inquiry, observation, 
and reflection, in addition to the evidence furnished in the fore- 
going Table,—as will be found more particularly adverted to im- 
mediately. 
2udly. With regard to the annual variations in the level of the 
kes, and their general extent; and how far these also occur 
simultaneously, and are likewise owing to the amount of rain 
and snow compared with that of the evaporation; or what other 
cause :—I am free to confess that, ceteris paribus, and in accord- 
ance with the various authorities adduced, as well as all other in- 
formation which I have been enabled to obtain, the same obser- 
vation must apply to these variations as to the septennial fluctu- 
ations just noticed: but that while the extremes between the 
maximum and minimum range of the: great floods may be rated 
at about six feet, the average difference of level during a single 
year may be between two and three feet; and that as already 
stated, though the-rise and fall in all the Lakes may usually be 
simultaneous, one may sometimes be low while the others are 
high. As, for instance, it will be seen by a reference to the 
* Miscellaneous Remarks,” that in 1795-96, Lake Ontario was 
so high as to drown trees of many years’ growth while Lake 
Erie was described as so low that the gravelly beach near Cleve- 
land was used asa public road; and that in 1814, ‘the upper 
Lakes were full,” whereas “the centre and lower Lakes” were 
not so till the following year; and that in 1827 Lakes Erie and 
Ontario were between two and three feet above their usual level, » 
while Lake Superior was lower than ever known before ;—all 
which circumstances combined, with others yet to be noticed, have 
produced a conviction that each Lake is independently liable to 
irregularities of level peculiar to itself. Lallude to the well known, 
ut little thought of, fact, that during the winter months large 
boulders as well as smaller masses of stone and gravel, lying along 
shore, become firmly imbedded in the bordage ice, and on any 
rise of the waters, towards the close of the season, remain firmly 
attached to the moving floating masses, liable to be either ad 
3 
the Lake. Admitting such to be the case—for there is every 
year abundant evidence of the fact—it only remains to suppose 
that towards the end of winter, as frequently occurs, an accumu- 
Szconp Series, Vol. XX, No. 58.— July, 1855. 7 
