f 
\ 
256 W. Hopkins on Changes of Climate. 
. Let us suppose Snowdon and the surrounding country lowered 
500 feet below its present level. If the whole of Europe were 
depressed to the same amount, a large portion of it would be sub- 
merged beneath the ocean; but we are at liberty to suppose any 
part of it depressed to a greater amount, if necessary to produce 
the more complete submergence here assumed. I have estimated 
the most probable mean annual temperature of Snowdon at 39° 
or 40° F., in the absence of the Gulf-stream (¢ 13, p. 77) and 
of any cold current from the north; and I have also shown that 
it would be little altered by the submergence of Europe beneath 
the sea (§ 18, p. 85). This would give the height of the line 
of 32° F’. equal to at least 2200 feet, or about 800 feet below the 
the 
northwest coast of Iceland, is, according to Makenzie, 
and that of the snow-line upon it 2734 feet, as measured Sr 
J.T. Stanley. The mean annual temperature there Js ee 
38°, and consequently the height of the line of 32° must On 
about 2000 feet, upwards of 700 feet below the snow-line. 
the south coast of Iceland the mean annual temperature 1S 
40°, and the height of the line of 32°, consequently, —— 
3000 feet. The height of Eyafialla Jokul is about 5500 1%) 
and the height of the snow-line is probably much igen nger® 
Snefell. The glaciers there are stated to descend nearly 0" 
level of the sea. Pa ‘sland of 
I have estimated the mean annual temperature of the be at 
8S. Georgia at 38°. Consequently, the line of 32° will more 
about the elevation of 2000 feet. It is very desirable that snow" 
accurate observations should be made on the height of the 
ea that island than, I believe, have haiherte: Se vgs to tle 
vague assertion that the snow-line there descelu ~ 
isen from confounding ** 
vel of. the ocean, has probably arisen from eegee 
