440 P. H. Carpenter's Physical Investigations on the " Valorous" 



which is indicated by the next sounding, shows that it must 

 rapidly die out toward the east. 



The course of the " Valorous " having then been kept at first 

 nearly due east, and afterward southeast, another serial tem- 

 perature-sounding was taken on the 19th of August, in 

 56° 11' N., and longitude 37° 41' W. The surface-temperature 

 had here risen to 53°,— about the same as we had encountered 

 in the "Lightning Channel," at the same time of the year, 

 rather farther to the north ; but the warm upper stratum was 

 here thinner, a reduction to 45° taking place within fifty 

 fathoms, and to 40° within 300 ; whereas in latitude 59° 35' N., 

 longitude 9° 11' W., we had found the isotherm of 45° lying 

 below 500 fathoms, while the bottom at 767 fathoms was still 

 41 4°. It is obvious moreover, from the regularity of the de- 

 scent of the isotherm of 40° in this part of the North Atlantic, 

 that easting has more influence on the rate of that descent than 

 thus confirming the view formerly expressed as to 

 the tendency of the warm upper flow toward the eastern side 

 of the basin.* The isotherms of 39° and 38° slope downward 

 toward the east at about the same rate ; but thoae of 37° and 

 36° still nearly keep their parallelism to the surface, confirming 

 the previous suggestion of the "neutrality" of the deep stratum 

 which they underlie. 



Between the last station and the next, taken in latitude 56° 

 1' N., and longitude 34° 42' W., in the line of the channel be- 

 tween Iceland and Greenland, but considerably to the south of 

 it, the sea-bed was found to have shallowed most remarkably, 

 bottom being struck at 690 fathoms, and the bottom-tempera- 

 ture rising again to 382°. This elevation may be regarded 

 with great probability as a continuation of that which was 

 encountered by Sir L. McClintock in the line of temperature- 

 soundings which he took several years ago across the North 

 Atlantic between Eockall and Cape Farewell ; for almost 

 exactly in a line between the " Valorous " Station 13 and Ice- 

 land, Sir L. McClintock met with bottom at 743 fathoms, 

 between 1,260 fathoms on the east and 1,159 fathoms on the 



The course being now again kept nearly due east, another 

 temperature-sounding was obtained in latitude 55° 58' N, 

 longitude 31° 41' W., which, on a bottom of 1,230 fathoms, 

 gave a bottom-temperature of 36-8°, the surface-temperature 

 being 54-5°. Three degrees farther east, and on the same 

 parallel, another set of serial temperatures was taken, which 

 indicated a further increase in the upper warm stratum, the 

 isotherm of 40° descending to about 380 fathoms; but the 

 r Scientific Researches, 1872, §§ 144, 148, (Proc. Roy. Soc., xx, PP- 



