411 THE CANADIAN NATURALIST. [Vol. VU. 



LAKE ERIE. 



By canal surveys in Xcw York, 1817, 561.20 feet. 



By Capt. Williams report of 1834, Nia^^,Hra tSliip Caual, 563.00 '' 



By surveys Caatskill & Portland Kailway, 1828, 565.33 " 



By loeUs of New York Canal, 567.00 « 



(f 



Mean, 564.13 feet. 



LAKE HURON. 



S. W. Higgiiis, Geological lieport of Michigan, 1838, 577 feet. 



A. Murray, Geological Report of Canada, 1849, 578 " 



Mtiiu, 577J feet. 



Lake tSt. Clair, Geological f{?port Michigan, 570 " 



LAKE MICHIGAN. 



Southern Michigan Railway, J.H. Sargent Engineer, survey 



of 1856, south end 583 feet. 



LAKE SUPERIOR. 



By Cayt. Baytield's harometical measurement in 1824, 627 



feet, evidently too great. 

 A. Murray's determination. Geological Survey of Canada, 



1849, 599.4 1 feet, say 600 feet. 



Survey of Bay D'Enoch k Marquette Rail Road, 1859, 610 '< 



Mean 605 feet. 



