METEOROLOGY, 



419 



isobars, and Brault believes that a similar coiucidence occurs for other 

 portions of the earth and other seasons. {Nature, xxvii, p. 20.) 



A. Domojirof describes in the Isvestia of the St. Petersburg Geograph- 

 ical Societj- what little is known of anemometric observations at sea. 

 Several series of such observations have been made, notably by Bessels 

 on the Polaris (1872), Bykatchefi" on board the Nayezdnik (1879), and 

 by Domojirof on the Nordenskjold (1879) and theBjighit (1880). {Na- 

 ture, XXVI, p. 83.) 



W. Clement Ley, in studying the relation between wind force and 

 the barometric gradient, gives the following mean wind velocities at 

 Stonyhurst Observatory, obtained by himself from the hourly readings 

 published by the Meteorological Committee for the years 1874 to 187G, 

 inclusive, for. difl'erent amounts of atmospheric gradient: 



The mean velocities at Kew Observatory for the same period for simi- 

 lar gradients are as follows: 



This shows that for any given (moderate) gradient winds from north 

 and east points are stronger than from south and west points at these 

 stations. {Nature, May 5, 1881, xxiv, p. 8-) 



Ealph Abercromby has read before the Meteorological Society of 

 London a paper on the diurnal variations of winds and weather in 

 relation to isobars by constructing charts for various hours of the same 

 day. He finds, as has been explained by Koppen and Terrel, that by the 

 same gradient there is more wind by day than by night ; and that, again, 

 in cyclones the wind curves inward more by night than by day. The 

 mean diurnal frequency of rain increases during the daytime, and this is 

 explained by the fact that in any given cyclone the area of rainfall is 

 larger by day than by night. {Nature, xxvi, p. 95.) 



C. A. Stevenson records the velocity of the wind in the southwest 

 gale of November 21, 22, 1881, at Edinburgh: Mean velocity, 62.3 miles 



