TRANSACTIONS OF SECTION E. 455 
Captain Scott is of opinion that this great ice-sheet is afloat throughout, and 
I entirely agree with this conclusion. It is unexpected, but everything points 
to it. 
From soundings obtained along the face it undoubtedly has about 600 feet of 
water under it. . 
It is difficult to believe that this enormous weight of ice, 450 miles by at least 
360, and perhaps very much more, with no fall to help it along by gravity, can 
have behind it a sufficient force in true land glacier to overcome the stupendous 
friction and put it in motion if it be resting on the bottom. It is sufficiently 
astonishing that there is force enough even to overcome the cohesion at the side, 
which must be very great. 
The flat nature of the bottom of the Ross Sea and the analogies of many 
geographical details in other parts of the world make it most probable that the water 
under the whole barrier is deep. 
A point on which I have seen no comment is the difference in the appearance 
of the slopes of Mount Terror. Captain Scott found the bare land showing over 
large areas, but during the two summers of Ross’s visit it was wholly snow-clad. 
Sir Joseph Hooker, the sole survivor of Ross’s expedition, when questioned had no 
doubt on the subject, and produced many sketches in support. 
This may be due to temporary causes, but all the information collected by the 
expedition points without doubt to steadily diminishing glaciation in recent times, 
We have, therefore, this interesting fact, that both in Arctic and Antarctic regions, 
as indeed all over the world, ice conditions are simultaneously ameliorating, and 
theories of alternate northern and southern maximum glaciations seem so far 
disproved. 
But this does not mean that climatic conditions in the Antaretic are now less 
severe—probably the contrary. It has been pointed out by many that land 
glaciation may arise from varied primary causes, but one obvious necessity is that 
the snowfall should exceed melting and evaporation. It need not be heavy ; but 
if it is, it may produce glaciation under somewhat unexpected conditions. This 
would entail a vapour-laden air more or less continuously impinging upon the 
land at a temperature which will enable it when cooled, either by passing over 
chilled land or when raised to higher regions by the interposition of mountains, 
to give up its moisture freely. This condition is not fulfilled when the air as it 
arrives from the sea is already at a very low temperature. 
It was my fortune to spend two long seasons in the Straits of Magellan, and I 
was daily more impressed by what I saw. 
There you have a mountainous ridge of no great height—very few peaks rising 
more than 4,000 feet—opposed to the almost continuous westerly winds pouring 
in from the Pacific at a very moderate temperature and charged with much 
moisture. 
The result is that in the latitude of Yorkshire every mountain mass over 
3,000 feet high is covered with eternal snow, and sends glaciers down to the sea. 
I was convinced by what was going on under my eyes that it only required an 
upheaval of the land of 2,000 feet or so to cover the whole of Patagonia with ice. 
But then the climate would still not be very severe. The temperature of the 
wind from the sea would be the same, and such part of it as blew along the 
pinels and on the lower land would moderate the cold caused by the ice-covered 
slopes. 
AThe shores of the whole of Western Southern Patagonia, deeply indented with 
long and deep fiords, indicate, according to all received views of the origin of 
such formations, that the land was formerly higher, while signs of glaciation are 
everywhere present. 
The results of geographical research show us that in many parts of the world 
climate must have greatly changed in comparatively recent times. 
In the now arid regions of Northern Africa, Central North America, and in 
parts of Asia there is ample evidence that the climate was in times past more 
humid. In aremarkable paper on the causes of changes of climate, contributed 
