THE VOYAGE OF H.M.S. CHALLENGER. 
Sir James Clark 
Rosa' Antarctic 
Expedition. 
Introduction op 
Time Intervals 
in Sounding, 
Row’ Dredgings 
in Deep Water. 
7 * 
A Brit i - t Antarctic Expedition under Sir James Clark Ross sailed in the “Erebus” 
and “ T rror in I§39, and returned safely in 1843. Like Sir John Ross in the Arctic 
vo) ires, his nephew was determined to make the most of his opportunities in all direc- 
tion.'. md was seconded in his efforts by the able co-operation of Dr., afterwards Sir, 
Joseph D. Hooker, who aeccompanied the expedition as assistant surgeon. Without 
n< '_d< uiug his main purpose — the exploration of the ice-bound coasts of the southern 
hemisph* ix and the search for the South Magnetic Pole — he carried on astronomical, 
physical, and zoological work, and achieved important results. 
A number of unsuccessful attempts were made to ascertain the depth of the water in 
mid-ocean, the failure being due to the want of a proper line. Sir James Ross accord- 
ingly had one made on board, 3600 fathoms long, fitted here and there with swivels to 
pi vent it unlaying in its descent, and made strong enough to support a weight of 76 lbs. 
On the 3rd January 1840, when in lat. 27° 26' S. and long. 17° 29' W., the first 
abysmal sounding was satisfactorily taken with the new line, the depth marked being 
2425 1 fathoms. Sounding in such great depths could only be attempted in dead calm 
weather, and the line was allowed to run out from an enormous reel in one of the ship’s 
boats, the time each 100 fathom mark left the reel being noted in the usual way. On the 
3rd March 1840, a sounding of 2677 fathoms was taken in lat. 33° 21' S. and long. 9° 
E., 450 miles west of the Cape of Good Hope. Water of equal depth was frequently 
sounded during the cruise, and on two occasions at least no bottom could be found with 
over 4000 fathoms of line. 
The dredgings which were taken occasionally turned out to be one of the most 
valuable parts of the scientific work of the expedition. On the 21st April 1840, a 
haul of the dredge was taken in 95 fathoms of water, and it came up full of coral. On 
the 18th January 1841, when in lat. 72° 57' S. and long. 176° 6' E., a Crustacean 
[Xymphon cjracilc ) was found attached to the lead, after a sounding in 20 fathoms. 
Next day, when the depth was 270 fathoms, a dredge was put over, and when hauled up 
was found to be nearly full ; it contained a block of granite, a number of small stones, 
some beautiful specimens of living corals, and, to quote Captain Ross’s own words : — 
“ Corallines, Flustrae, and a variety of marine invertebrate animals, also came up in 
the net, showing an abundance and great variety of animal life. Amongst them I 
detected two species of Pycnogonum , Idotea baffini, hitherto considered peculiar to the 
Arctic Seas, a Chiton, seven or eight bivalves and univalves, an unknown species of 
f ia mmarus, and two kinds of Serpula adhering to the pebbles and shells.”” On 20th 
January 1841, the deep-sea clamm brought up stiff green mud containing corals and 
fra jm-nts of starfish from a depth of 320 fathoms. Two days later the dredge was kept 
out for vend hours in 300 fathoms, and its contents included “many animals, some 
1 AnUrrtic Voyage, vol. i. p. 46. 
1 Ibid., p. 203. 
