296 



METEOROLOGY AND ALLIED SUBJECTS. 



Woeikof , gives a summary of our knowledge of the winds on the 

 Atlantic Ocean, in which, among other things, he gives the following 

 table showing the mean limits of the northern border of the region of 

 the northeast trade winds. Thus on 45th meridian west, from April to 

 June, the average latitude of the northern limit of the northeast trade 

 winds is 27°. 



{Z. 0. G. M., Vol. XV, 1880, p. 124.) 



In reference to the winds of the valley of the Upper Engadin in 

 Switzerland, Professor Billwiller, in a review of the recently crowned 

 essay of Dr. Ludwig, says, "After I had made an accurate review of the 

 continuous records of the meteorological stations, and, by direct ques- 

 tionings of reliable persons, had found the fact confirmed that really on 

 warm, clear summer and autumn days, about midday, there regularly 

 prevailed a local wind flowing downwards in the direction of the river from 

 Maloja Pass to beyond the Scaufs, which attained its greatest intensity 

 in the warmer hours of afternoon, and toward evening again died away, 

 I attempted to find an explanation for this phenomenon, which ap- 

 parently stands in contradiction to the theory of the mountain and val- 

 ley winds." The exj)lanation of this phenomenon depends essentially 

 upon the topograi^hical peculiarities. The meteorological conditions of 

 the Ober-Engadin are entirely the same as those of an inclosed valley. 

 The temperature variations are much greater than those of the lower 

 land beneath it, by reason of the dry, pure, thin air. The insolation in 

 snmmer produces an ascent of the air on the flanks of the valley that 

 is followed by a diminution in the i^ressure and density of the air im- 

 mediately above the lowest portions of the long, narrow valley of the 

 Inn, and which demands a compensation. Since now active ascending 

 currents are moving along the southern base of the Alps, nothing is 

 more natural than to assume that the deficiency in density in the base 

 of the valley of the Ober-Engadin should find its compensation by 

 drawing upon the cooler and somewhat denser air on the other side 

 but at the same level in the valley of the Maloja. — [Z. 0. G. 3L, Vol. 

 XV, 1880, p. 297.) 



O. T. Sherman has published the result of observations made by him- 

 self, in balloons, on the height and strength of land and sea breezes. 

 The observations were made at Coney Island, near New York, at the 

 expense of Capt. H. W. Howgate, and at the request of Professor Abbe, 



