166 Major Lachlan on the Rise and Fall of the Lakes. 
it is evident that the present rise (1838) is higher than has oecur- 
red for many years before, for extensive tracts of forest are now 
overflowed, and timber killed in consequence, the trees of which 
indicate a long period of growth. he causes that may concur 
to produce such a variation in the level of the Lake are :—Ist, 
An obstruction to the drainage to the usual quantity of water, in 
consequence of which, if the usual supply continues, the water 
must rise. 2d, The increased or diminished supply of water, de- 
dependent on the wetness or dryness of the season, the relative 
temperature, and amount of evaporation, both from the surface 
of the Lake and the country which receives its drainage waters, 
and the amount of water supplied by the Lakes above, as Lakes 
Huron, Michigan, and Superior,—the amount of water contribu- 
ted by ‘which is due to the same general causes, with the possible 
addition of an increasing water-way from the cutting down o 
their outlets, and pouring down an additional supply. 3d, An- 
other possible cause may be taken into account in the varying 
level (or upheaval) of the solid earth itself—examples of which 
are mentioned-in various works on geology, as to be seen in part 
of the coast of Sweden, where it is said to be slowly rising at 
the present time.’ 
To this the as well adds ;—“ It is considered an object 
of great importance to determine what are the cuuses of this 
effect ; and it was therefore intended, if the Legislature had made 
an appropriation corresponding to the estimate, and with provisions 
to the Bill which was reported last Session, to have set in train a 
series of observations in several localities on the Lake coast, and 
in different parts of the States, so that by the period for the ‘close 
of the survey, a determination of the causes of the rise and fall 
of the Lake might have been attained. All the aid which the 
various branches of meteorology could have secured would also 
have decided the question as . the small tides, which are said to 
be very sensible in some place 
To the foregoing remarks’ of robo Mather, I may be per- 
mitted to add that it is much to be regretted that any circum- 
stances should have prevented his excellent suggestion from being 
carried into effect ; but that such having unfortunately been the 
case, it now remains for the British province of Canada to have 
the credit of completing so desirable a work, on a far more eX- 
tended scale. 
‘urning again to Lake Superior, I am happy to be able to 
quote'the following (abridged) remarks by the same writer :* 
ae great rise and fall of the level of the waters of the great 
ae aseries of years has been long noticed. The 
ess due to a greater quantity of snow and rain, oF 
