Surface Temperature. 29 



the Pacific. The surface-temperature of these seas in the 

 warmest part of the year ranges above 2 8° C, and in the Red 

 Sea rises to 32 C. The highest surface-temperature observed 

 on board H.M.S. "Challenger" was 3i°.i C. (88° F.), and was 

 recorded on the 21st October, 1874, in the Sea of Celebes, 

 in lat. 4 14' N., long. 124 18' E. The lowest, of -2°.8 C. 

 (2 7 F.), was registered on two occasions, on the 18th and 24th 

 February of the same year, in about lat. 65 S., when surrounded 

 by icebergs ; as the temperature of the water a few hours 

 before and after these observations was several degrees higher, 

 the ship must have passed through what may be called pools of 

 water of this low temperature. 



One of the most remarkable examples of the influence of 

 oceanic currents upon the distribution of temperature occurs in 

 the North Atlantic and the adjoining portion of the Arctic 

 basin. The cold current which flows down along the east coast 

 of Greenland, and, after rounding Cape Farewell, joins the 

 Labrador current, carries the western end of the isotherm of 

 o° C. down to the latitude of Newfoundland, while its eastern 

 extremity is advanced as far as lat. 8o° N. by a warm current 

 which, after bathing the west coast of the British Islands and of 

 Norway, penetrates into the North Polar regions along the 

 coast of Spitzbergen. Thus this isotherm forms an oblique 

 line extending from Newfoundland over Iceland and Jan Mayen 

 to the northern end of Spitzbergen. The effect of the above- 

 mentioned warm current, generally considered an extension of 

 the Gulf Stream current, upon the climate of the British Islands 

 is well known. In its absence, or if its place were occupied by 

 a polar current — which probably was the case in a former 

 period in the history of our planet — the climate of these islands 

 would resemble the actual climate of Labrador. 



If we consider the narrow limits of temperature, including 

 but a few decrees of the thermometric scale, which determine 



