THE EFFECT OF POLAR ICE ON THE WEATHER. 183 



interest of coming generations, as I had done a quarter of 

 a century before. 



I assume that most of you are fairly posted up in the 

 literature of Antarctic Exploration during the last twenty 

 years, which from time to time has been so ably summarised 

 by Sir Clements Markham, and other Presidents of the 

 Royal Geographical Society. Previous to this, we were 

 restricted to the data supplied in the early part of the 

 nineteenth century by Biscoe, Bellamy, Dumont d'Urville 

 and Wilkes, ending with the voyages of Captain James 

 Ross, 1841-3, which closed the early history of Antarctic 

 exploration, and was to receive no addition for fifty years. 

 Half a century passed, a nation had arisen in the Australian 

 colonies, almost daily visited by vessels improved to the 

 latest developments of naval architecture, and no longer 

 dependent on the chance winds of heaven for clawing off a 

 lee shore, or beating a hasty retreat from unexpected 

 troubles, and yet it has seemed impossible to awaken any 

 active interest in obtaining further data for our guidance. 

 You will probably allow that I was justified twenty-seven 

 years ago in thinking, that "if any cyclical periods of 

 varying position of the ice-limit exist, we may for ever 

 remain in ignorance of the great natural causes of such 

 oscillation," but my life has been spared long enough to 

 allow me to alter that opinion ; the explorations of 

 Lieutenant Peary, United States Navy, in Greenland have 

 shown a gigantic ice cap of unknown depth, 1,000 to perhaps 

 5,000 feet, covering an area of 25,000 to 30,000 square 

 miles ; the present theory appears to be that this great 

 mass, increased every year by successive layers of snow, 

 where rain never falls, and snow never melts, with its 

 superincumbent weight exercises an enormous dynamic 

 pressure on the glaciers and ice-cliffs at its foot, forcing 

 them out to sea in the shape of bergs, which extend some- 



