PALAEOLITHIC RACES 331 



overwhelmed. The great terminal moraine which marks the 

 southern boundary of the ice can be traced with occasional 

 interruptions from Nantucket through Long Island past New 

 York towards the western extremity of Lake Erie, then along 

 a sinuous course in the same direction as the Ohio, down to its 

 confluence with the Mississippi ; then it follows the Missouri 

 as far as Kansas City, and beyond runs approximately parallel 

 to that river, but south of it, through Nebraska, Dakota and 

 Montana, and Washington, where it meets the coast north 

 of Columbia river. Within this boundary nearly the half of 

 North America was buried beneath a thick sheet of ice, flowing 

 more or less radiately outwards from a central region situated in 

 and about the region of Hudson Bay. 



The co-existence of two continental ice-caps, one on each side 

 of the Atlantic Ocean, must have produced a very profound effect 

 on the climate of the Northern hemisphere ; and it can scarcely 

 have originated without a general lowering of the temperature, 

 probably to the extent of 5 C. more or less, over that part of the 

 Northern hemisphere, which lies outside the Tropic of Cancer. 



A similar fall of temperature seems to have affected the 

 Southern hemisphere. If we turn to our antipodes we discover 

 obvious signs of the former existence of glaciers in the Kosciusko 

 plateau or Muniong range of New South Wales (lat. 36 22' S., 

 height 7,328 ft.). The snow-fields on the watershed gave birth 

 to glaciers which flowed down the valleys on each side ; to the 

 west to a level of at most 6,300 ft., to the east of 5,800 or 

 perhaps 5,500 ft. The largest of these glaciers was only a few 

 hundred feet in thickness and three miles in length. 1 The facts 

 observed in the Kosciusko plateau indicate a former lowering of 

 the snow-line to the extent of 2,200 to 2,700 ft. 



In Tasmania, the former existence of Pleistocene glaciers has 

 long been known, 2 and they point to a lowering of the snow-line 

 to the extent of 4,000 ft. 



1 David, Helms, and Pitman, " Geological Notes on Kosciusko, with special 

 reference to Evidence of Glacial Action," Proc. Linn. Soc. N.S. IV. 1901, pp. 26-74, 

 plates. This memoir contains a valuable bibliography on the Pleistocene 

 glaciation of the Southern hemisphere. 



2 T. B. Moore, " Discovery of Glaciation in the Vicinity of Mount Tyndall, etc.," 

 Papers and Proc. R. Soc. Tasmania for 1893, pp. 147-9 ( l8 94), an d "Notes on 

 Further Proofs of Glaciation at Lower Levels," Op. cit. (1896), pp. 73-7. The 

 latest work on the subject is by J. W. Gregory, "A Contribution to the Glacial 

 Geology of Tasmania," Quart. Journ. Geol. Soc. 1904, vol. lx. pp. 37-62, plates. 



