NARRATIVE OF THE CRUISE. 
887 
1842, a reference to which will show, as previously mentioned, that the mean temperature 
of the sea is invariably warmer than that of the air during the winter months. Now, 
as it is a fact well ascertained that the current in the vicinity of the Falkland group sets 
from the southwest towards the northeast, and as this current is warmer than the air, 
there can be but one way of accounting for its heat ; that is, by supposing it to derive 
this warmth from lower latitudes in the Pacific, and to be carried by the prevailing 
winds and configuration of the land round Cape Horn and northeastward to the 
Falklands. 
That this agrees with the temperatures recorded on the western coast of Patagonia 
will be seen by referring to No. 11 pamphlet of the Meteorological Committee, as the 
mean temperature of the sea in the squares adjacent to the coast is from 2° to 4° 
higher than that of the air during the months of May, June, and July. On leaving the 
Falkland Islands and standing to the eastward, vessels generally obtain colder surface 
temperatures than those at the group. In the Challenger a decrease of 3° was registered 
to the northeastward of Port Stanley. 
What the width of this warm portion of the Cape Horn Current is, remains to be 
determined, and also whether its speed is greater than that of the drift current farther 
south. The available evidence points to a considerable velocity at times, for the 
“ Chanticleer ” registered a speed of 54 miles in 23 hours between Cape Horn and Staten 
Island in May. During the “ Beagle’s ” stay in the vicinity of Tierra del Fuego, sur- 
veying, the current was always found running to the eastward, but its velocity varied 
with the tidal wave, being at its maximum with a rising and at its minimum with a 
falling tide. 
A series of charts, showing the surface temperatures of the Atlantic, Indian, and 
Pacific Oceans, has recently been published by the authority of the Meteorological 
Council, in which many more observations are given off Cape Horn. 1 These observations 
confirm this conclusion, but observations closer to the shore than those on the charts 
would probably show a still higher temperature of the surface waters. As there is very 
considerable interest attached to this current around Cape Horn, it is to be hoped that 
further observations will soon be made. 
The following table will give a fair idea of the climate of the settlement at Port 
Stanley, but as the observations extend over one year only, the means will be subject to 
modification from future observations. The barometer used in taking the observations 
was a standard, and its indications agreed precisely with those of the instruments on 
board the Challenger, which were verified at Kew at the termination as well as at the 
commencement of the voyage. 
1 Charts showing the Surface Temperature of the Atlantic, Indian, and Pacific Oceans. London, 1884. 
(narr. chall. exp. — vol. i. — 1885.) 112 
