THE CLIMATE OF GEE AT BRITAIN. 267 



the American continent near Washington. Still ap- 

 proaching the tropics, it travels through the northern 

 parts of Texas, where it reaches its greatest southerly 

 range. Passing gradually northwards to the neigh- 

 bourhood of the Aleutian Islands, it thence trends 

 southwards again, passes through the Corea, traverses 

 the Asiatic continent nearly on the latitude-parallel 

 of Nankin ; thence travelling slightly northwards, it 

 crosses the southern part of the Caspian Sea, the Black 

 Sea, and the north of Turkey, passing through Venice 

 and Paris to London. On the continents the isochi- 

 menal falls outside (that is, south of) the annual iso- 

 therm, while on the oceans the reverse holds. The 

 projection of the isochimenal thus appears as an 

 irregular oval, whose greatest length lies on the con- 

 tinents. 



We see here, again, the indication of a tendency to 

 form two curves, and thus of the presence of two poles 

 of extreme winter cold in the northern hemisphere. 

 The isochimenals of greatest cold hitherto traced in 

 the two continents are shown by two broken curves 

 in Fig. 1. The cold of the Asiatic curve is very much 

 greater than that of the Amerfcan, the former curve 

 marking a winter cold of 40 Fahrenheit (72 below 

 freezing), the latter a winter cold of 26 5', only if 

 one may apply such an adverb to a cold of 58 5' below 

 freezing. Professor Nichol remarks that, 'if a polar 

 projection were made of these regions for January, it 

 would be found that the two coldest spaces of these 

 continents form a continuous band passing across the 



