580 Capt. F. W. Sutton — A Glacial Epoch in S. Hemisphere ? 



shores of the North Atlantic, the occurrence of extreme cold, dependent 

 on the winters occurring when the earth is at its greatest distance 

 from the Sun, and during great eccentricity of its orbit, is inadequate 

 to cause glacial conditions in the British Isles and Eastern Europe. 

 The same reasoning which has been used to demonstrate it will also 

 apply to their occurrence as a consequence of a supposed increase of 

 the obliquity of the Ecliptic. 1 The diversion of the Gulf Stream is 

 upon all hands considered sufficient to produce all those effects which 

 occurred in Britain during the Glacial Period ; and there are many 

 evidences which tend to prove that subsidence of the isthmus has 

 taken place, so as to allow of this change in the direction of the 

 Equatorial Current, but, to obtain absolute proof, it is requisite that 

 investigations, with this object in view, be made in Nicaragua and 

 other parts of Central America. 



II. — Did the Cold of the Glacial Epoch extend over the 

 Southern Hemisphere ? 



By Capt. F. W. Hutton, F.G.S. 



SO many geologists appear to take it for granted that the cold of 

 the Glacial Epoch extended over the whole earth that a few 

 words of caution from the Southern Hemisphere may not perhaps 

 be out of place. 



The existence in the Pleistocene Period of a Glacial Epoch in 

 Europe and North America having been firmly established, the 

 former greater extension of glaciers in many other parts of the 

 world is considered to be explained by the Glacial Epoch, and at 

 the same time is taken as a proof of the universal extent of the 

 cold, and therefore of its cosmical origin. But we must remember 

 that out of a number of mountain chains which reach above the 

 level of perpetual snow, those only would not show traces of a 

 former greater extension of their glaciers which now happen to 

 stand at a higher elevation than in past ages ; and of the chains 

 that do not now attain to the limit of perpetual snow, but had 

 passed that limit at some previous period in their history, would 

 also show traces of former glaciation. So that a former greater 

 extension of glaciers in a district by no means proves a general 

 reduction of temperature ; and I need hardly point out that we 

 have but two means of proving a former reduction of temperature 

 at the sea-level, viz. (1) the migration of a fauna towards the 

 Equator, caused by the gradually increasing cold; and (2) the 

 former extension of glaciers into the sea in places where at present 

 they terminate at a certain height above it ; and in the latter case 

 the difference of level must be so great that it could not be accounted 

 for by a former greater snow-fall in the district. Now I believe that 

 no good evidence of either one or other of these has been adduced 

 in any country in the Southern Hemisphere, and until this is done 



1 Climate of the Glacial Period. By Thomas Belt, F.G.S. Quart. Journ. of 

 Science, 1874, page 461. Variations in the Obliquity of the Ecliptic. By Colonel 

 A. "W. Drayson, F.R.A.S. Quart. Journ. of Science, 1875, page 279. 



