from the Falkland Islands to Monte Video. 627 



We sounded in 1425 fathoms on " Glohigerina-ooze," with a bottom- 

 temperature of 2°'3 0. The trawl had failed so frequently of late, that 

 we determined to send down instead a large light dredge, which we had 

 had made at Hong-Kong for the shallow-water sponge-producing seas of 

 the Philippines. It came up with scarcely any ooze, and with only a 

 small number of animal species ; but among them were many very perfect 

 specimens of the rare little sea-urchin, JSalenia varispina. It is singular 

 that although there were a large number of hempen tangles attached to 

 the dredge, and they seemed to have done their work well, none of the 

 Bryozoa so characteristic of moderate depths, with a bottom of " Globi- 

 gerina- ooze," in the Atlantic were taken on this occasion. In the 

 evening we made sail due north. 



This portion of the voyage divides itself into two parts with very 

 different conditions — the nearly meridional passage from the Falkland 

 Islands to Monte Video, a distance of 1100 miles ; and the line from 

 Monte Video to Station 335, a little to the south of the parallel of 35° S. 

 for a distance of 2100 miles. 



Between Stanley and Monte Video four observing-stations were 

 established, numbered on the charts and diagrams from 317 to 320. Two 

 of these were in comparatively shallow water near the edge of, but still 

 upon, the plateau which extends from the coast of South America to a 

 distance of nearly 400 miles, and includes the Falkland Islands ; the two 

 remaining soundings, 318 and 319, were well beyond the cliff of the pla- 

 teau at depths greater than 2000 fathoms. The shallow-water soundings 

 were upon hard ground ; in the two others the bottom was a greyish mud, 

 to a great extent composed of land detritus. All these soundings, the 

 two deep ones particularly, indicate the presence of a great underlying 

 mass of cold water, the isothermobath of 2° C. occurring at Station 318 

 at a depth of 125 fathoms. At Station 319 the 2°-0. line is at 1100 

 fathoms, and the other isothermobath s up to 5° C. show a corresponding 

 rise. I attribute this remarkable difference between two soundings so 

 near one another to the banking of the cold water against the submarine 

 cliff by the Brazil current ; sounding 118 seems to have fallen directly 

 upon the " cold wall." 



At the deeper sounding (319) the thermometer fell, for the first time 

 in our experience in the South Atlantic, below the freezing-point ; but the 

 relations of this very low bottom-temperature will be better understood 

 when we come to consider the section between Monte Video and Tristan 

 d'Acunha. 



On the line between Monte Video and Station 335, fifteen observing- 

 stations were established. The first three of these, 321 to 323, were on 

 the estuary of the Biver Plate, or (323) just beyond the edge of the delta 

 at its mouth ; the next seven, 324 to 330, gave a section of a wide inlet 

 into the western trough of the South Atlantic with a mean depth of 

 2750 fathoms ; and the remaining five stations, 331 to 335, were on the 



