264 



ON THE HYDROLOGY OF TIIK HASIN 



fully drawn to the subject, and appropriation was made accordingly, to effect the clearing 

 up, and buoying and lighting of a channel; and since that time, viz., frem and including 

 the year 1857, to the end of 1858, the total quantity of dredging done was one hundred 

 and fifty thousand seven hundred and sixty cubic yards, and the charmed at the upper 

 end was made two hundred feet wide, the average widtli being two hundred and seventy- 

 five feet wide. 



The channel is now excavated to insure a minimum depth of twelve feet throughout ; 

 and in the middle of the channel, for a width of two hundred and thirty feet, the depth 

 is thirteen feet. 



The total appropriation to the work was $45,000 from the United States Government, 

 and $20,000 from the Canadian Government, and the work has hitherto appeared to be 

 perfectly satisfactory ; and the South Pass is now the master current into the lake. 



The material excavated was removed to a distance of five hundred yards from the 

 channel, and re-deposited in the lake. It consisted for the most part of sand, gravel, and 

 mud, with a little hard-pan and drift, corresponding with the drift found on the Michigan 

 peninsula. 



The cost per cubic yard was : 



Sand, gravel, and mud, 



Hard-pan, or concreted clay and sand, . 



$0 80 

 1 50 



There are three main channels or passes through the delta, known as the North, Middle, 

 and South Passes, — the latter being the one selected for the operations described, and 

 forming the boundary line between Canada and the United States. 



1 C E. 



The phenomena attending the formation of the ice, and its removal, which form the 

 natural limits to all the economical operations of the people living within the district, 

 deserve especial consideration. During the long winters, in -the earlier periods of the; 

 history of the country, the people were driven to their homes, without much occupation 

 beyond what was essential to the support of existence. It was a period of four months, 

 with a mean temperature of twelve degrees below the freezing point, — but with extreme 

 fluctuations, of deep snows, — and during which, if they could not obey the same instincts 

 which led most of the animals of this vast region to migrate, they would follow that of 

 others which were fitted for hibernation. It is this curtailment, perhaps, of a third part 

 of the year which has encouraged — if it has not developed — that remarkable activity and 

 change in habits (rapid as the changes of the temperature itself), observable in every 

 person and in every operation, upon the opening of navigation. 



