424 Eighth Axxual Report of the 



in its course over the Pacific, it touches America in southern 

 California, follows the Rocky mountains northward to British 

 America and thence takes a southeasterly direction to the 

 Great Lakes and New York. 



In Januar}-, New York is to be classed with quite different 

 regions of the globe from those named above. The isotherm of 

 15 degrees, which appears near the northern boundary of the 

 State, passes thence over Labrador, the southeastern coast of 

 Greenland and the Arctic Ocean. When well to the northward 

 of Scandinavia it turns southeastward through Central Russia 

 (passing north of St. Petersburgh) to the northern border of the 

 Caspian Sea. Proceeding eastward to northern Japan and north- 

 eastward over the Pacific it reaches the southern coast of Alaska^ 

 when it again trends southward to South Dakota and finally passes 

 north of the Lake Region to the St. Lawrence valley. 



The mean January temperature of 30 degrees (that of New York 

 city) is found also in southern Newfoundland, Iceland and northern 

 Norway. This isotherm turns sharply southwiard in the latter 

 region and passes to eastern Germany, Austria and the northern 

 border of the Black Sea, when its course becomes eastward to the 

 Pacific. Like all the precediing lines it intersects Japan and thence 

 passes northeastward to the Aleutian Islands. Following the 

 American coast line to the border of the United States, it turns 

 southeastward to Missouri and thence passes to the southern shore 

 of the Great Lakes. 



As may be seen by the table on page 422, there are but few 

 regions of the globe in which the cold gains so rapidly with increase 

 of latitude as in the vicinity of New York, especially in the winter 

 This condition is due to the influence of the Great Lakes^ which 

 alfect central and southern New York much more than the north- 

 em section^ and also to the fact that the path of low pressure areas 

 lies in close proximity to the State. 



From the forms of the isothermals of charts 1 and 2 it is apparent 

 that, after eliminating the differences of temperature due to eleva- 

 tion above sea-level, there remain three important sources of local 



