86 DR. ROBERT BELL 
low temperature of these high latitudes, and, owing to their great mass, they would gain 
heat slowly in the short summers. It is well known that each berg is surrounded by a 
wide zone of cold water, and that, in thick weather, the proximity of one of them to a ship 
may be discovered by hauling a bucket of water on deck and testing it with a thermometer. 
As the berg moves south with the ocean current, it carries its chilly zone with it, like a 
planet surrounded by its atmosphere. The Gulf Stream spreads itself on the surface of the 
Arctic Current, and towards its edge it is probably not deep. The berg, extending down 
to a great depth, is borne with comparative rapidity into the opposite-flowing warm 
surface-current. The zone of very cold water, which until now has remained around the 
berg, is immediately swept away, exposing its surface suddenly to a temperature, perhaps 
30° Fah. warmer than it has ever experienced before. This rapid change would, no 
doubt, cause the ice to crack and fall to pieces in a very short time. The berg, lightened 
above, would rise and so bring up new parts of the old ice to be acted upon by the warm 
water, which would always be increasing in depth. The fresh surface of the fragments 
of the berg, having the low temperature of its interior, would be immediately acted on in 
the same way, and these would, in their turn, become fractured over and over again, 
until the whole mass was reduced to a multitude of small pieces, floating on the surface 
of the warm water, with warm air above it. As they became scattered about, the process 
of fracturing, owing to the contrast in temperatures, would continue to go on, and thus 
every trace of the berg would quickly vanish. In order to test the behaviour of ice at a 
low temperature when suddenly immersed in warm water, the following experiment 
was performed in Ottawa on February 27th, 1886. A piece of ice, weighing about ten 
pounds, which had been freely exposed to the outer air, having then a temperature of 
—5° Fah., was brought into the house, wrapped in a fur rug, to protect it from the heat, 
and plunged into a bath of water at a temperature of 87° Fah. Instantly, it began to 
crack in all directions, with distinct detonations, which could be heard in all parts of the 
room. In explanation of the fact that icebergs are occasionally met with far south of 
their usual limit, it may be suggested that these have been retarded by stranding or by 
gales of wind near the Newfoundland coast until their temperature has been raised; and 
that then, floating south-westward near the land, they have afterwards been carried out 
towards mid-ocean by the Gulf Stream. 
It is supposed by some that icebergs have been the means of transporting vast 
quantities of earthy and rocky materials from north to south in former geological times, 
and that this action is still going on. There does not, however, seem to be much foun- 
dation for such speculations. Out of the great number of bergs seen during the two 
voyages above referred to, only a few had any foreign matter, or even marks of disco- 
loration upon them. It was remarked that towards the entrance to Hudson Strait, cases 
of the kind were most frequent among the bergs furthest east. In the event of a berg 
carrying such matter, it would naturally become more visible as the surface melted by 
the sun’s heat on coming south, and if any were present, it should be perceptible by the 
time the berg reached the latitude of Cape Race; yet, out of the large number which 
may often be seen from the deck of an Atlantic steamer near this cape, it is very seldom 
that one is noticed carrying any earth or stones. It would, therefore, appear that icebergs 
have played only a small part in the transportation of boulders or earth during either 
Post-Pliocene or modern times. 
