352 FROM EDINBURGH TO THE ANTARCTIC 
that of the North. In parts we found it very closely 
packed; in parts it was more open and easy to penetrate. 
Sea. — The colour of the sea varies very much. Now it 
is blue and clear ; now olive-brown, and opaque. Be- 
tween these two colours there is a series of shades from 
greenish blue, dark green, and olive green, and from clear- 
ness to opacity. The browner water appears to be in the 
neighbourhood of a great body of ice. This colour is due 
to a diatom, which swarms in the water, and which colours 
the pack-ice and the base of bergs with a rusty brown. 
In the bluest water it was most profitable to hunt for 
seals. Ross and other navigators experienced the most 
terrific swells in the pack, but we escaped them even after 
the heaviest gales. In the neighbourhood of the Danger 
Islets the currents were very strong — at times it was 
difficult for our vessel to make headway against them. 
In the neighbourhood of bergs they were also impetuous. 
I was in one of two boats one day, in the neighbourhood^^ 
of a berg, and so strong was the current that, although 
we pulled steadily for about four hours, we were only+just 
able to hold our own against it. Near bergs the drift-ice 
moves very fast — now onward, now swaying round caught 
in a whirlpool, and boats have to keep a sharp look-out to 
prevent being nipped. Surface and deep-sea temperatures 
were recorded, and it is of interest to note that for the 
first time in Antarctic Seas the reversing thermometer 
was used. On two or three occasions we saw ice form- 
ing on the water, but never to any great extent. Besides 
temperatures, salinities were recorded, and several 
