1903-4. ] THE FLUCTUATIONS OF LAKE ONTARIO. 9 
inches. The harbour records from 1854 to 1903 show a diminution of 
the water level of Lake Ontario of 13.61 inches. This great diminution 
in fifty years demands close scrutiny and enquiry, as the diminution of 
the rain and snowfalls does not explain the discrepancy. During the 
last period of ten years the Sanitary Canal at Chicago has been com- 
pleted, and the outlet from Lake Ontario, at the Galops rapids, has 
been deepened, which may account for the extraordinary diminution. I 
have no accurate data with respect to these constructions, but when it 
is considered that the drainage of Chicago has been diverted from Lake 
Michigan to the River Mississippi, the water levels of Lakes Michigan, 
Huron, Erie and Ontario must be considerably affected. An expert was 
appointed by the Dominion Government to examine and report on the 
discharge of the Sanitary Canal at Chicago, but I am not aware that 
any examination or report was made. The Dominion Government is 
now constructing a dam between the Galops and Adam’s Islands, at the 
head of the Galops rapids. This dam is only constructed in order to 
increase the depth of water in the rapids, but not intended to raise the 
water level of Lake Ontario. The decrease in the water levels of the 
lakes can be rectified by engineering skill—in fact a dam has already 
been recommended to be constructed across the Niagara River, near 
Buffalo, to regulate the water level of Lake Erie, and the Detroit River, 
but the diminution of the rain and snowfalls cannot be checked except 
by replanting and reforestation. As the period of low water on Lake 
Ontario occurs generally during the winter months, the shipping in- 
terests are not much affected, but dredging is constantly required in the 
harbours round Lake Ontario. 
The record of extraordinary fluctuations is limited to one instance, 
which was detected by Denison’s automatic gauge, placed in the storm 
signal hcuse at the Queen’s Wharf, by the Dominion Government in 
1898, the particulars of which I notified Mr. Stupart on November 29th, 
1900, requesting to be informed if there was any unusual disturbance of 
the barometer at the Observatory at that time. “On Monday, the 26th 
inst., there was an extraordinary fluctuation of the lake level from 5.45 
to 6 a.m., wind strong from the north-west. The feading at 5.45 a.m. 
was 1.60 inches above Dominion zero, in ten minutes the reading was 
a little below 1.00, and in fifteen minutes it went up to 2.25 inches, at 
6 a.m. The level gradually subsided to the normal reading for the day.” 
On November 30th Mr. Stupart replied : “I enclose herewith a print of 
our barogram, showing a marked and rapid change of barometer at 
about the time you say there was an extraordinary fluctuation in lake 
level. The change of reading between 5 o'clock, and the lowest, 5.30, 
