Page:Polar Exploration - Bruce - 1911.djvu/161

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ANIMAL LIFE
157

putting out 2,000 fathoms (=2¼ miles) of cable, but it did not touch the bottom, and this occurred more than once in this locality. The only way that this could be accounted for was that there were strong under-currents sweeping the trawl off the ground; for during the previous year, in about 2,500 fathoms, bottom was reached with 3,100 fathoms of cable, or only 600 fathoms extra beyond the depth, instead of 800 as on this occasion.

On the 21st of March, however, in lat. 69° 33′ S., 15° 19′ W., the Scotia secured a good haul in 2,620[1] fathoms (=3 miles) on a bottom of blue mud. In order to make sure of the trawl reaching the bottom, we fixed four furnace bars, each weighing 22 lbs., and two olive-shaped weights on the cable, each of 20 lbs. An extra 1,000 fathoms of cable were let out, that is to say, 3,620 fathoms (4⅛ miles) in all. The trawl began going out at 10.15 a.m., and was on board again at 6.33 p.m.; this time there had been about 500 fathoms of cable on the bottom, showing that we could have done on this occasion with our usual allowance of 500 or 600 extra fathoms. The dynamometer registered up to 5 tons. The trawl came up with a great deal of mud and many big stones,

  1. At 2,620 fathoms there is a pressure on any object of about 2½ tons per square inch, reckoning 1 ton per 1,000 fathoms.