412 
GEOLOGY OF THE FOURTH DISTRICT. 
Table of the mean length, breadth, depth, elevation and area of the Great Lakes and the 
River St. Lawrence* 
Mean length. 
Mean 
breadth. 
Mean depth. 
1 Elevation 
above the le¬ 
vel of the sea. 
Area. 
Miles. 
Miles. 
Feet. 
Feet. 
Square miles. 
Lake Superior,.__ 
400 
80 
900 
596 
32,000 
Green Bay, __ 
100 
20 
500 
578 
2,000 
Lake Michigan,___ 
320 
70 
1,000 
578 
22,400 
Lake Huron,____ 
240 
80 
1,000 
578 
20,400 
Lake St. Clair,_ 
20 
18 
20 
570 
360 
Lake Erie,___ 
240 
40 
84 
565 
9,600 
Lake Ontario,___ 
180 
35 
500 
232 
6,300 
River St, Lawrence,..._ 
20 
940 
94,000 
It will be perceived that there are some differences in the two preceding tables ; and not 
having the means of deciding the absolute truth, both are given. These are to be regarded 
as an approximation to the truth, rather than as absolutely correct. 
The following are the elevations of the principal lakes within the district. 
—-——— - 
Above Lake 
Ontario. 
Above tide 
water. 
Feet. 
Feet. 
Cayliga lake, ____ 
156 
387 
Seneca lake,__ 
216 
447 
Crooked lake,_ 
487 
718 
Canandaigua lake,..__ 
437 
668 
Chautauque lake,_ 
1,060 
1,291 
The elevation of the other lakes is not known with sufficient accuracy to give them in this 
table. 
The three following tables of elevations, from the paper of Prof. Henry before quoted, 
present three lines of section in a north and south direction across the district. 
Report of Dr. Hooghton, State Geologist of Michigan. 
