B. TERRESTRIAL PHYSICS AND METEOROLOGY. 69 



namely, that of the anti-trades and, at a great elevation, 

 continue undisturbed from west or west-southwest to east- 

 northeast. Observations are not complete enough to establish 

 the latter proposition, but numerous concordant statements 

 render it so probable that it seems worthy of the attention 

 of local and other observers. 



In North America, where the axis around which the wind 

 veers lies decidedly between northwest and southeast, as in 

 Eastern Asia, the fact seems better substantiated than in 

 Europe (can, indeed, be considered as fixed), and the infer- 

 ence is justifiable that the condition on the eastern coast of 

 Asia is similar. Russell verifies by his own observations in 

 Canada, in Washington, the Southern States, and Cuba, the 

 statement of Espy, that in the United States there is an un- 

 varying upper current of air from the Avest. Blodgett asserts 

 that at Philadelphia, at all seasons, a western current can, 

 not unfrequently, be detected by cirrus clouds. In Northern 

 Asia, even on the east coast, no exact information on this 

 point has been supplied, on account of the neglect to notice 

 particularly cirrus clouds. In interior Asia a few definite 

 observations can be given, and on the east coast of Siberia a 

 few at least not contradictory ones, inasmuch as the existence 

 of cirrus clouds has been noted with varying inferior winds, 

 but without oiviiicr their direction. If it should be demon- 

 strated, then, which the writer does not doubt, that the high 

 cirrus clouds, the greatest elevation of which can be placed 

 at 40,000 feet, on the east side of the two cold poles do not 

 take part in the variation of the anti-trades from a west- 

 southwest to southeast direction, but that these elevated 

 masses of ice crystals and flakes continue unaffected in the 

 normal direction imparted by the earth's rotation, the fact 

 will be of the highest importance in giving a more correct 

 exhibition of the total movement of the atmosphere, and lead 

 to the conclusion that the whole depth of the atmosphere 

 does not find the initial and final point of its motion in the 

 region of the greatest cold, but that a very considerable and 

 more elevated portion moves above this, having this point at 

 the geographical pole of the earth. There would be in this 

 . a new proof that the whole atmosphere takes part in the cir- 

 culation between the equator and the poles, and that the 

 cause of the movement is not simply the difference of tem- 



