114 The A liter lean Geoloyiaf. February, i8f 5 
that time the outtiow by the St. Chiir river has i)r()babl3^ never 
been interrui)ted, and i'roni this fact there J'oUows an impor- 
tant conclusion. At the present time lalce Erie is nearly nine 
i'eet below lal^e Huron.* It follows that at about nine feet 
above tlie water to the head of the Niagara river at Buffalo 
there is a point in the air which is now exactly in the plane of 
lake Huron. And since the outtiow of the upper lakes has 
been through Niagara ever since the establishment of the St. 
Clair outlet, it follows further that this same point must have 
been at all times very nearly in the plane of lake Huron, de- 
parting from it only so far as the fall from lake Huron to lake 
Erie may have changed, or the Niagara river lowered its level 
at its head by erosion. As we shall see later, it is certain 
that the fall from Huron to Erie was a little greater at first 
than now. But both these factors together are evidently' 
small, probably not exceeding 10 or 12 feet at most, making 
the fall at that time about 20 feet. The relation of the plane, 
of lake Huron to the head of Niagara river must have been 
very nearly the same all the time. It follows that at the last 
hour of lake Algonquin thrs point nine feet above the river at 
Burt'alo was only 10 or 12 feet below the plane of the Nipis- 
sing beach. For this reason then, that plane is extended by 
inference to Buffalo, and that place becomes the hinge upon 
which all the subsequent eastward elements of deformation 
turn. But Bufl'alo is almost exactly east of Port Huron so 
that the whole relative change between them has been an east- 
ward component. Kelative eastward elevation has taken place, 
probably amounting to 35 feet at Buffalo. This would be 
enough to drown the Nipissing beach about 25 feet at Port 
Huron ; and the St. Clair and Detroit rivers were aleo similarly 
affected. Since this has taken place, Buffalo has become vir- 
tually the hinge of the northward component of deformation 
also. The truth of this is evident when we consider that the 
present level of lake Huron is to a considerable extent de- 
pendent upon the level of lake Erie. If Erie were to run dry, 
the level of Huron would speedily be lowered b}^ several feet, 
presumably by 25 feet or to the former level of the St. Clair 
outlet. Buffalo is nearly straight south of North Bay so that 
*"PhysicH] Characteristics of tho Northern and Northwestern Lakes," 
L. Y. Schcrmerhorn, C. E., Am. .lour. Sci.. III. vol. xxxiii, April, 1887. 
