president's address. 845 



A general alteration of climate over the surface of the earth 

 might l)e caused by an alteration in the constitution of the atmos- 

 phere. Mr. H. C. Russell at a meeting of the Roj^al Society of 

 New South Wales in 1892 pointed out, when giving some 

 particulars of probable life conditions on the Planet Mars, 

 tliat the existence of a thin layer of olefiant gas in the 

 atmosphere of this planet would allow the sun's heat to enter, but 

 would prevent its radiation again into space, so that the existence 

 of the addition of small quantities of such a gas if liberated by 

 extensive volcanic disturbances from coal strata below would be 

 the cause of materially raising the general temperature of the 

 earth's surface. On the other hand, if the earth with the sun 

 passed into regions of space which happened to be crowded 

 with meteoric matter, the power of the sun's rays would be so 

 much diminished that a considerable enlargement of the polar 

 area and an extension of glacial phenomena into temperate regions 

 would result. 



In "The Climates of the Geological Past," Mr. Eugene Dubois 

 shows how that in all ages up to the end of the Tertiary Period 

 mild temperatures have been proved to exist up to within 10 or 

 15 degrees of the North Pole, and in the Eocene we have such 

 in Grinell Land at 8 If N., 95° W.; Spitzbergen 771° to 79" N., 

 about 20° E., while in the Island of New Siberia in latitude 75.^° 

 and 140° east longitude dejjosits of brown coal are found. In the 

 southern hemisphere it has not been possible to penetrate so far, 

 but in Kerguelen, which now has a rigorous climate, Cupresso.vjjlon 

 has been found, while at Punta Arenas, in the Straits of Magellan, 

 53|° S., the conditions appear to have been tropical. The author 

 concurs with Heer in disputing the fact of any'indication of geo- 

 graphical shifting of the pole, as the vegetation follows close on the 

 pole all round, and if the ancient conditions seem to have been 

 warmer on the Atlantic side, it is only similar to what is the case 

 now. In the early Tertiary especially this intensity of conditions 

 producing warmth might well have been even greater than now, as 

 Europe consisted of islands and peninsulas, with inland seas and 

 large bays, and there is little doubt that the Arctic Ocean was at that 



