152 SIEGE OF THE SOUTH POLE 
this way at the end of summer, and he argued that when 
the summer temperature of the air fell at nights far be- 
low the freezing point the winter temperature must be 
very severe indeed, and consequently the surface of the 
sea may be frozen to a considerable depth. The 
frozen sea-water might be freshened, he thought, by the 
continuous addition of snow, and the outcome of his ob- 
servations was to the effect that the field-ice might be 
formed in the open sea, and that consequently its pres- 
ence was not necessarily a sign of the proximity of land. 
In this, he was no doubt substantially correct; but he 
went farther in his speculations as to the origin of ice- 
bergs. After brooding over the matter for a fortnight 
he came to the conclusion that icebergs also were 
creatures of the sea and not of the land, as had always 
been held before. He knew that Captain Weddell had 
reported a berg so impregnated with earth as to make it 
look like a piece of rock, but he himself had seen hun- 
dreds of bergs, all of unsullied purity and not one of them 
bore the least trace of any connection with the land. 
They might, he thought, be the product of the perpetual 
freezing of a tranquil sea “ accumulating with time.” It 
was the experience of February 25th, 1831, that convinced 
Biscoe of the truth of this theory. An “ appearance of 
land ” had been seen the night before in latitude 
66° 29' S., longitude 45 0 17' E., but at noon: 
“ That which lately had the appearance of land now 
bore from E. S. E. to W. S. W. (true bearing), with 
a large range of field-ice stretching to the N. E. 
Innumerable icebergs, and the vessels so encom- 
passed with straggling pieces we could proceed no 
further with safety owing to a strong N. E. swell, which 
set towards the main body of ice, which it now proved to 
