258 W. Hopkins on Changes of Climate. 
tion, however, between the western coast of South America and 
that of Europe consists in the great difference in the heights of 
their mountains. A glacier is described by Mr. Darwin* as de- 
scending to the sea-level in the Gulf of Penas, on the west coast 
of America, in latitude 46° 40’. According to Dove's 
map, we have for that place— ie 
July temperature, . ; ; : 407 Fes 
January temperature, : : ; 50 ta five 
Mean annual temperature, . : ; A5 N 
Hence the height of the line of 329 must be about 4500 feet. 
The difference between the January and July temperatures 1s 
only 10°, the latter being considerably reduced by the cold cur- 
rent passing round Cape Horn. This, with the proximity of the 
Pacific, is highly favorable to a low position of the snow-line. 
It may probably lie near the line of 32°, or even connieas 
lower, in which case the glacier must descend between 4000 a 
5000 feet below it. This coincides with the distances to which 
almost all glaciers of the first order descend below the snow-line 
($ 23, p. 252) and presents nothing anomalous. It is described as 
a very large glacier, descending from a lofty mountain, which 
rises, undoubtedly, many thousand feet above the snow-line. It 
is in this respect that the analogy between the glaciers of South 
America and those which may have formerly existed on such 
mountains as those of the British Islands entirely fails. With 
the same climatal conditions, we might have glaciers descending 
tis sea-level in the one case, without a trace of glaciers in the 
other. 
29. I shall now discuss the case of the Alps. Adopting the 
hypothesis of a current from the north, it is manifest that such & 
current would, as already remarked, tend much to equalize tb 
temperature from the latitude of Snowdon to that of the Alps 1, 
the present region of western Europe, precisely as the Gulf-stream 
now equalizes in so remarkable a degree the temperatures of the 
than at present, and the latter also to the production of S20 
. * Darwin’s Journal, p. 284. 2 
