GEOLOGICAL CLIMATES. 735 
In Nature, vol. xxill. p, 242, Prof. Haughton says, ‘‘The thickness of this 
ideal ice-cap at the Pole is unknown, but, from what we know of the Palzeocrystic 
ice of Banks Land and Grinnel Land, must be measured by hundreds of feet, and its 
mean temperature must be at least 20° F. below the freezing point of water.”’ 
With regard to both the above assumptions—which are in italics—I must beg 
to disagree entirely with the learned Professor. He appears to consider the so- 
called Paleeocrystic ice as the normal state of the ice at and near the Pole, and as 
a natural growth by the gradual freezings or increase of a single floe during a 
series of years; whereas I am of opinion that this mis-called Palzocrystic ice is the 
result of a number of floes being forced over and under each other by immense 
pressure caused by gales of wind and currents. 
The western and northern shores of Banks and Grinnel Lands are peculiarly 
well suited for the formation of such ice heaps; as they are exposed to the full 
force of the prevailing north and northwest storms, which pile up the ice in a 
wonderful manner on these shores and others similarly placed, fora distance of miles 
seaward. The whole of the west shore of Melville Peninsula isso lined with rough 
ice of this kind that sledging is impossible. 
It will wholly depend upon the form of land—if any—at or near the Pole, 
whether or not any floebergs are there. If there is no land it is probable there 
will be few or none, as the ice will meet with no great obstruction, as it is driven 
by winds and currents. 
I have no authorities by me that give the thickness of ice formed in one sea- 
son at or near the winter quarters of any of the Arctic expeditions, except my 
own in 1853-4 at Repulse Bay, latitude 66° 32’ north. 
The measurements of the ice—taken at some distance out in the bay, where 
there was very little snow—and the mean temperature of the airaregiven. 
LOGS) ce thickness Increase Monthly Mean Temp. F. ~ 
December 2oun-.-4 feet 7 1nehess. on .-.24°°5 below zero 
1854 
es 24 225 (eet O|Imches) ee tay win) 25 days aoi3 Olas On ua ue 
MelruaTya 25th cs7) Leet Sane .-16 in 32 days eae Wace OG 
April 25 Sngtey Nh Ws eb ...1234 in 59 days ee Oia Seas ob 
May 25 Sribsoniteny Geilo -.none 30 days ---24° above zero 
The above table shows that the ice ceased to increase in thickness some time 
between April 25 and May 25. after which it decreased rapidly ; but I was unable 
to decide what proportion of this decrease was due to thaw and evaporation from 
the surface, and what amount from the lower part of the floe that was under water ; 
no doubt by far the greater effect was produced by the first two causes. 
Eight feet may perhaps be considered a fair or rather a high average of one 
winter’s formation of new ice (not increase of an old floe) over the whole of the 
Arctic Sea ; because Repulse Bay, although in a comparatively low latitude, was 
particularly favorable for ice-formation, there being no currents of any conse- 
quence. Where there are currents, one year’s ice does not exceed three or four 
feet. 5 
The winter’s ice of 1875-6 at Discovery Bay, in latitude 81° 40’ N., did not 
