ix Climates of the World 135 



coldest regions are the centres of the great continents. 

 The coldest place where observations have ever been 

 made, is the Siberian village of Verkhoyansk just within 

 the Arctic Circle (see Plate VII.) On account of the 

 Arctic Sea being frozen across in winter, this village lies 

 close to the centre of the northern continental mass. The 

 mean January temperature at this station is 61 below zero, 

 Fahrenheit ; and the absolutely lowest temperature ever 

 experienced by human beings occurred there in January 

 1886, which was 89 F. The powerful influence of the 

 warm surface-water of the Gulf Stream ( 244) on the air 

 is shown by the temperature of the Lofoten Islands, in the 

 same latitude as Verkjflpyansk, being above 32, the differ- 

 ence between the two being more than 93. The coldest 

 point in the American continent lies a little north of the 

 magnetic pole ( 98), and has a temperature of 40. In 

 order to appreciate the effect of land and sea in modifying 

 climate the student should carefully follow the isotherms of 

 30 and 40, noting carefully the latitude at which these 

 temperatures prevail near the coast and in the heart of 

 continents. To make this exercise still more instructive, 

 the lines might be traced on the contoured map (Plate XL), 

 and the actual surface temperatures calculated. 



190. Air Temperature in July. The lapse of six 

 months brings round the northern summer and southern 

 winter. The Sun now vertical near the Tropic of Cancer 

 beats down upon a far greater breadth of land surface than 

 in January, and so the area with a temperature exceeding 

 90 in North America, North Africa, and Asia extends far 

 to northward of the tropic. The sea now exercises a cool- 

 ing influence on the air of the middle latitudes in the 

 northern hemisphere. The isotherm of 70 F., for example, 

 runs far to the north over the continents, reaching 55 N. in 

 North America, and 58 N. in Eastern Asia, but it scarcely 

 gets north of 40 N. in the Atlantic, and is carried south 

 to 25 N. by the Pacific. In higher north latitudes the 

 slight north-eastward trend of the isotherms shows that 

 some warming effect is still due to south-west winds and 

 currents. In July the Lofoten Islands, having warmed up 



