322 SIEGE OF THE SOUTH POLE 
the Erebus and Terror reached the meridian of 12 ° W. 
and found at last that the edge of the pack trended south- 
ward. Following it up and working westward as well 
as southward through fog and snow, Ross crossed the 
Antarctic circle on March 1st, 1843. Next day the sun 
appeared unclouded for the first time for six weeks, and 
the early part of the day was magnificent though the 
sea was rough. The latitude was found to be 68° 14' S. 
and the longitude 12 0 20' W. The following day was 
-aim, and the boats were got out with the longest sound- 
• ng-lines to make a deep-sea sounding. Four thousand 
fathoms, or 24,000 feet of line were coiled on a huge 
drum in one of the boats and the whole length ran out 
ithout the bottom being found. It was the deepest 
junding ever made up to that date, and as Ross was 
vperienced in the work and the conditions were en- 
’ rely favourable, it seemed not unreasonable to believe 
that a very great depth existed in that position. The 
ecent soundings of Mr. W. S. Bruce in the Scotia with- 
1 one mile of Ross’s position however, make it plain that 
die thick hemp line, caught by the strong undercurrent 
which runs there, floated the comparatively light sinker 
employed and so gave a fallacious reading. The real 
depth proved to be 2,660 fathoms. Temperatures were 
observed down to 1,050 fathoms, but as in the rest of 
Ross’s deep-sea soundings what he measured was not 
the temperature of the water but the compression of the 
thermometer bulb, for his instruments were defective. 
On March 4th the 70th parallel was crossed about 
midway between the tracks of Weddell and Bellings- 
hausen. Next day the pack was sighted, and as the ice 
seemed open at the edge the ships were run into it for 
a distance of 27 miles, when the pack became close and 
