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Second Glaciation 
The conditions and events of the first glaciation were repeated. 
The ice from Labrador again extended down to southernmost 
New England or Long Island Sound; and when it reached there a 
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temperature rise checked its growth. 
Second Interglacial Epoch 
The disappearance of the second ice sheet introduced a long 
interglacial interval during which the temperature may have be- 
come higher than it is in our time. This 1s suggested above all by 
rich subfossil remains of plants and animals at Toronto and on the 
\ 
oose River, near the southern end of Hudson Bay. 
Third and Fourth Glaciations 
Again history repeated itself. For the third time a huge ice 
sheet developed and disappeared, and after a new interval a fourth 
ice sheet formed, waxed, and waned. 
Four or Five Glaciations? 
The records of some of the events lying hundreds of thousands 
of years before our time are obscure, especially since each new 
ice shield swept away almost all traces and deposits of the pre- 
vious ice. It is therefore not vet surely known, whether there 
were four or five consccutive ice sheets separated by interglacials. 
The Last Glaciation 
At any rate, the last ice sheet, be it number four or five, in- 
terests us more than any of the others. This ice sheet, called the 
Wisconsin ice (after the State of Wisconsin), like its predecessors, 
developed in Labrador, to the south and west of Hudson Bay, and 
in the Canadian Cordillera. During its greatest extent it covered 
practically the entire northern half of the North American con- 
tinent from the Atlantic to the Pacific. It extended down to be- 
iow the International Boundary in the West, to Cincinnati far 
below the Great Lakes, to the mouth of the Hudson, and to a line 
running through central Long Island to Montauk Point, through 
B 
paint 
ock Island, Martha’s Vineyard, and Nantucket. It had an area 
