74 F. B. TAYLOR—ORIGIN OF GORGE OF WHIRLPOOL RAPIDS. 
it would leave a record in the gorge, for during that time the falls would 
have only the discharge of lake Erie, and the gorge made then would 
be shallow and narrow in comparison and it would be made much more 
slowly. 
Nipissing Great lake-—All the lands bordering the three upper Great 
lakes have been explored more or less thoroughly, the old abandoned 
beaches have been measured and traced for thousands of miles, and the 
current-worn beds of the several old outlet channels have been examined. 
As a result, the following facts pertinent to this paper have been found : 
Besides a probable temporary discharge through the Trent valley, with 
which we are not especially concerned here, the three upper lakes dis- 
charged for a relatively long time by way of the Nipissing or North Bay 
outlet. The most strongly developed beach that has been found in the 
upper lake basins leads to the North Bay outlet and i° no other, although 
it apparently falls but little below the present outlet at Port Huron. In 
its present attitude this beach is tilted so as to descend toward the south- 
southwest nearly 7 inches per mile, and it passes under the present lakes 
Huron and Michigan in their southern parts and under the west end of 
lake Superior. This is called the Nipissing beach, and the very large 
triple lake of that time is known as Nipissing Great lake.* 
Nipissing-Mattawa river—The abandoned bed of the outlet river of 
this great lake has been traced through the Mattawa valley from North 
Bay to the village of Mattawa, where the Mattawa river joins the 
Ottawa, a distance of about 40 miles. The descent of the river between 
these places was somewhat less than 150 feet, and all of it, excepting 
one fall or cascade of 30 or 40 feet, was accomplshed by rapids of mod- 
erate declivity. In a previous paper, in which a brief account of this 
river was given, it was proposed to call it the Nipissing-Mattawa river.y 
Space permits the enumeration here of only a few of the principal facts 
relating to it. The region is rough and rocky, the country rock being 
mainly gneiss and red granite of the hardest quality. The modern Mat- 
tawa river is made up of a chain of lakes, mostly long and deep and 
narrow and connected by short bouldery or rocky rapids. Some of these 
lakes are simply canyons, standing two-thirds or three-fourths full of 
* The writer proposed this name and has used it hitherto in the plural number, ‘* The Nipissing 
Great lakes.” The name was first suggested in a paper read by the writer before the Fortnightly 
Club of Fort Wayne, Indiana, Dee. 2, 1895, entitled “A sketch of the quaternary history of the 
Great lakes.” An abstract under the same title was afterwards printed in the Public Oceurrent 
(weekly), Fort Wayne, Indiana, vol, 1, no. 2, pp. 6 and 7, Dee. 14,1895. In a recent paper on “ Modifi- 
eation of the Great lakes by earth movement” (Nat. Geog. Magazine, yol. viii, Sept., 1897), Mr 
G. K. Gilbert uses the name in the singular number, ‘‘ Nipissing Great lake,” and speaks of it as 
a‘‘triple lake.’ Mr Gilbert’s suggestion seems to bean improyement, and the name will be used 
in the singular form henceforth. 
+ F. B. Taylor; ** The Nipissing-Mattawa river, the outlet of the Nipissing Great lakes,” (Ab- 
stract) Jour. of Geology, vol. v, no. 2, 1897, p. 220. Same in “Science,” Jan, 15, 1897, p. 90, 
a 
