30 TRANSACTIONS OF THE CANADIAN INSTITUTE. [ VOL. Walle 
south by ranges of mountains. As the dam was cut away the water fell 
step by step to its present level. Lyell prefers to think that these ridges 
and other marks of ancient water levels were formed by the sea, since 
he cannot imagine where the barrier assumed by Roy could have 
existed.* It is evident that in 1842 the long discussed question as to 
the marine or fresh water origin of the Iroquois and other raised beaches 
had already taken its place as one demanding solution. 
On the south shore of Ontario this beach was clearly recognised in 
1843 by Hall, who describes the gravel ridges used as roads, and states 
that these beach gravels contain wood, and, as he was informed, shells 
also ; the first fossils noted from beds of Iroquois age. 
It was sixteen years later before much further attention was directed 
to this old beach, A. C. Ramsay mentioning briefly the Iroquois terrace 
north of Toronto in 1859 ;+ while in the following year Charles Robb, 
C.E., of Hamilton, Ontario, describes a succession of ridges of sand and 
sravel, seven in number, seen as one goes inland from Lake Ontario. 
He refers particularly to the old Burlington beach and heights, stating 
that they rise 110 feet above the lake, a more correct estimate than 
Roy’s of the same beach at Toronto. He looks on the drift as due to 
iceberg action.t| In 1861 Professor E. J. Chapman, of Toronto Uni- 
versity, describing the drift deposits of Western Canada (meaning 
Ontario), mentions the fresh water shells found on old beaches near 
Collingwood and elsewhere, and thinks that an immense fresh water lake 
formed these beaches in succession as it gradually fell, evidently holding 
a view somewhat like Roy’s.§ 
In the same year Sandford Fleming gave a good account of a portion 
of the Iroquois beach northwest of Toronto in a paper read before the 
Canadian Institute, describing the terrace plain at the foot of Davenport 
ridge (which is an old shore cliff), and the gravel spit near Carlton 
station. He gives a rough but fairly correct map of the spit, and of a 
bay of old Lake Iroquois to the north.| 
In 1862 Newberry described “ the ice wall of the retreating glacier as 
forming the northern shore of the fresh water inland sea,’** and so 
introduced an entirely new element into the discussion. In 1882 Dr. 
Spencer published his work on the Iroquois beach north of Lake 
* Lyell, Travels in North America, Vol. II., p. 108. 
t Quart. Jour. Geol. Soc., 1859, p. 203 ; and Can. Nat. and Geol., Vol. IV., p. 328. 
t Can. Jour. New Series, Vol. V., 1860, p, 509. 
§ Ibid, Vol. VI., 1861, p. 228. 
|| Ibid., pp. 247-253. 
** Prof. Fairchild’s presidential address before the Geol. Sect. of the Am. Assoc. Proc. Am. Assoc., 
Vol. XLVIL, 1898, p. 33. 
