624 Prof. W. Thomson on the Voyage of the c Challenger - 



bottom ; but a tow-net attached to the dredge-rope at the weights con- 

 tained a little gravel and one or two small organisms. The bottom- 

 temperature was 1°'7 C. 



The following day was fine, with light uncertain winds ; on the 10th it 

 was blowing half a gale and the sea was running too high for sounding- 

 operations. On the 11th the weather was fine, the wind becoming more 

 moderate towards noon ; at 10 a.m. we sounded and put down the trawl in 

 2040 fathoms, with a bottom of bluish mud containing many Globigerince, 

 and a bottom-temperature of +0 o, 3 C. The position of the sounding 

 was lat. 42° 32' S., long. 56° 27' W., about 200 miles to the eastward of 

 Yaldes Peninsula. Temperature-soundings were taken down to 1500 

 fathoms (Curve 318, Plate 27). This sounding gives a singularly rapid fall 

 from 14°*2 on the surface to 2° 0. at 125 fathoms ; the edge of the Ant- 

 arctic indraught appeared to be pushed up against the American shore 

 by the western border of the southern branch of the reflux of the equa- 

 torial current, as the Labrador current is banked up by its northern 

 branch, the result being no doubt increased in both cases by the flinging 

 up of the polar water against the western land-barrier on account of its 

 low initial velocity. 



On the 12th we sounded in 2425 fathoms, and took a series of tem- 

 peratures ; the upper temperatures were decidedly higher than they were 

 the day before, 5° occurring at 125 fathoms, 2°-5 at 700, and 2° C. at 

 1100 fathoms. The position of the sounding was lat. 41° 54' S., long. 

 54° 46' W. ; it was nearly double the distance of the previous sounding 

 from the 100-fathom line, which here nearly corresponds with a steep 

 submarine cliff of great height. The bottom -temperature was — o, 4 C. 

 (Curve 319, Plate 27). On the 14th we sounded in 600 fathoms on the 

 plateau extending from the South- American coast, opposite the estuary 

 of the Elver Plate, 144 miles from Lobos Island. "We took a set of 

 temperatures to the bottom, and found the gradation, so far as it went, 

 much the same as the day before ; the bottom-temperature was 2°*7 C. 

 On this occasion the trawl was most successful, and gave us a very 

 fair idea of the fauna of moderate depths along the coast; probably not 

 fewer than sixty species of different groups were recovered, including a 

 very handsome Pennatula between two and three feet in height, some 

 deep-sea corals of very special interest, which are being worked up by Mr. 

 Moseley, and some fine Echinoderms and sponges. On the 15th we 

 anchored in Monte-Video Poads. 



We left the anchorage at Monte Video at daybreak on the 25th 

 of February, and after swinging ship for errors of the compasses, we 

 proceeded down the estuary. In the afternoon the trawl was put down 

 in thirteen fathoms to get an idea of the fauna of the brackish water. 

 The species procured were comparatively few ; but among them was a 

 plentiful supply of an interesting Alcyonarian Ccelenterate of the genus 

 Menilla, which was new to us. On the two following days we crossed 



