ee sa nett 
Major Lachlan on the Rise and Fail of the Lakes. 169 
“'The great interest which this subject possesses, in connection 
with our Lake Harbors, as well as with those agricultural inter- 
ests connected with the flat lands bordering the Lakes and Rivers, 
may be a suflicient apology for introducing the following facts 
and reflections upon the subject. An accurate and satisfactory 
determination of the total rise and fall of the waters of the Lakes 
is a subject, the importance of which, in connection with some 
t our works of internal improvement and harbors, can at this 
time scarcely be appreciated. 
“Much confusion is conceived to have arisen in the minds of 
a portion of our citizens, in consequence of a confounding of the 
regular annual rise and fall to which the waters of the Lakes are 
subject, with that apparently irregular elevation and subsidence 
which only appears to be completed ina series of years; changes 
that are conceived to depend upon causes so widely different, 
that, while the one can be calculated with almost the same cer- 
tainty as the return of the seasons, the other can by no means be 
calculated with any degree of certainty. 
_ “Tt is well known to those who have been accustomed to no- 
tice the relative height of the water of the Lakes, that during the 
winter season, while the flow of water from the small streams is 
either partially or wholly checked by ice, and while the springs 
fail to discharge their accustomed quantity, the water of the lakes 
IS Invariably low. As the spring advances the snow that had 
fallen during the winter is changed to water, the springs receive 
their accustomed supply, and the small streams are again opened, 
their banks being full in proportion to the amount of snow which 
may have fallen during the winter, added to the rapidity with 
which it may have been melted. ‘The water of the Lakes, in 
Consequence of this suddenly increased quantity received from 
the immense number of tributaries, commences rising with the 
first Opening of the spring, and usually attains its greatest eleva- 
‘on—at least in the upper Lakes—sometime in the month of 
June or July. As the seasons advance, or during the summer 
and a large portion of the autumnal months, evaporation is in- 
creased, and the amount of water discharged by the streams les- 
sened, in consequence of which the water of the Lakes falls very 
gradually until the winter again sets in, when a still greater de- 
Pression takes place, from the renewed operations of the causes 
‘ready mentioned. 
nt, as it manifestly is, upon causes which are somewhat uni- 
®rm in their operation, must not be confounded with that eleva- 
Stoonp Sems, Vol. XIX, No. 56—March, 1855. 22 
