P. H. Carpenter's Physical Investigations on the "Valorous." 441 



depths of the isotherms of 39°, 38° and 37° show little change ; 

 and the bottom at 1,485 fathoms was 36*5°, as at the corre- 

 sponding depth on the other side of the ridge. Still farther- to 

 the east, in latitude 55° 10' N., longitude 25° 58' W., the depth 

 was found to have still further increased to 1,785 fathoms; but 

 the bottom showed no lower a temperature than 36-7°, although 

 in the 1,750 fathoms sounding on the other side of the ridge 

 the thermometer fell to mofe than three degrees lower. 



Bad weather having come on, it was not considered prudent, 

 in the disabled condition of the ship, to attempt further scien- 

 tific explorations ; and the course was accordingly shaped for 



The Temperature-Section prepared from the serial soundings 

 taken in the "Valorous " after quitting; Davis Strait has been 

 continued toward Valentia on the basis of the serial soundings 

 taken off the coast of Ireland in the first cruise of the " Porcu- 

 pine " in 1867, a sounding in 1,263 fathoms, latitude 56° 8' N., 

 longitude 13° 34' W., being taken as the principal guide. This 

 being almost on the same parallel with the last serial sounding 

 of the "Valorous," (the difference of latitude being only half a 

 degree), and the seasonal difference being rather in favor of the 

 " Valorous " temperatures, it is extremely striking to find in 

 this section the most remarkable contrast yet brought out 

 between the thermal condition of the eastern and the western 

 sides of the North Atlantic: for the descent of all the isotherms 

 as they pass from west to east, which has been already pointed 

 out in the "Valorous" portion of the section, continues at an 

 even more rapid rate ; so that the isotherm of 40°, which lay 

 XVI at 380 fathoms, lies at 900 fathoms at Station 

 XVII, fifteen degrees to the west ; while the isotherm of 45°, 

 which at the first of these stations lay at eighty fathoms from 

 the surface, lay in the second at 640 fathoms. This difference 

 in the thickness of the whole stratum above the isotherm of 

 40° is much more remarkable than the difference of surface- 

 temperature, the increase of which between the first and the 

 second station was only from 55° to 596°. 



It is clear, therefore, that the heating power of the warm 

 flow which comes up from the southwest toward the western 

 shores of the British Isles, and which proceeds onward to the 

 northeast, so as to ameliorate the climate of the Orkneys and 

 Shetland Islands, but still more markedly to affect that of the 

 coast of Norway (as has been shown by Professor Mohn), 

 depends upon its great depth. Any such superhe-^ 



the Gulf-stream has been found to be when last recognizable 

 as a current (as was long since urged by Mr. Findlay, and has 

 since been confirmed by Capt. Chimmo's observations), must 

 lose its excess of warmth long before it reaches our shores. 



