president's address. 631 



Taking Murray's estimate of the size of the south polar 

 continent as being about one-fortieth of the total atea of the 

 earth's surface, Lord Kelvin calculates that a layer of ice 

 1,200 feet in thickness covering this area — equivalent to a depth 

 of 1,000 feet of water — would, if melted and added to the ocean, 

 suffice to raise its level all over the globe by about 25 feet. In 

 like manner a withdrawal of the same amount of water would 

 cause a universal lowering of the ocean level by 25 feet. Were 

 there a similar accumulation at the Arctic pole, the total varia- 

 tion in ocean level would be 50 feet. There does not seem to be 

 any other way in which serious quantities of water could be 

 taken from the ocean or added thereto. Now Professor Suess in 

 his great work ' Das Antlitz der Erde,' published in 1884, an 

 English translation of which by Dr. Hertha Sollas and Professor 

 W. J. Sollas was brought out so recently as 1904,"*^ combats 

 altogether the theory of the rise of land masses. Suess considers 

 that all phenomena indicating a lowering of ocean level relative 

 to land are due to real alterations in the water level, and not to 

 any rising of the land. He concludes that any plateau consisting 

 of marine sedimentary rocks now existing at an altitude above 

 sea-level, indicates vertical alteration in the level of the water at 

 least equal to such altitude. We have seen that, assuming 

 an Arctic area available for storage of ice equal to that existing 

 in the Antarctic, an accumulation of 1,200 feet of ice over both 

 regions would be competent to produce a universal lowering of 

 about 50 feet in the ocean level, and that the maximum height 

 to which ice could be piled under polar conditions is considered 

 by Lord Kelvin to be about 3,000 feet. From these figures it is 

 easy to calculate that, given a uniform accumulation of ice to a 

 height of 3,000 feet over both polar regions, the difference in 

 ocean level would only be about 125 feet, while we have 

 innumerable large areas of marine sedimentary rocks at 

 enormously greater altitudes than this. While it thus seems 

 evident that the greatest possible accumulation of ice in the polar 



* Reviewed by J.W.G. in ' Nature,' June 29, 1905, P- 193. 



