Are Great Lakes Retaining their Ancient Level? 383 
ing with great force and evaporating effect when forming 
the dry rear semicircle of the revolving storms which pass 
over the lakes. An alteration in the meteorological condi- 
tions to cause for a period a preponderance of these winds 
in duration and force would. no doubt, have a marked 
effect on the water of the lakes. 
The Welland Canal is an additional outlet for Lake Erie, 
the Sault Canal for Lake Superior, the lower canals for the 
River St. Lawrence, and the deepening of St. Clair River 
for Lake Huron. But I leave it to hydraulic engineers to 
calculate the additional quantity of water carried off in this 
artificial way. 
Another interesting calculation would be the wearing 
effect of continual running water at the various rapid out- 
lets. It is possible the rocky outlets of these lakes are 
wearing deeper by this natural means. 
It is not necessary to say much about the reported sub- 
terranean passage from Lake Huron to the Gulf of St. Law- 
rence, because, if it exist, it is probably of very ancient 
origin, and may be considered a constant factor affecting 
equally both sides of the equation, the future and the past. 
Should any member of the Society have made a survey 
of this passage at any time, a few words from him about it 
might be interesting. This tradition has some value, how- 
ever, on account of its being handed down by seamen whose 
veracity on all matters maritime has never yet been impugned. 
In 1838 there seems to have been the highest stage of 
water of which we have any authentic record. This high 
water has been used by the United States authorities as the 
plane of reference for the soundings on their charts, and 
for the records of the oscillations to which I have alluded. 
From 1859 to 1887 the mean water-surface of Lake On- 
tario was 2°1 feet below the high water of 1838. There has 
been, on the whole, a gradual fall from 1859 to 1872, and a 
similar rise to 1888. [have not the records from 1888 to date, 
but have reason to believe the fall has been similar to that 
in Lakes Huron and Michigan, for which there are records 
to the end of last year. In Lake Ontario during this period 
