DISCUSSION AND ANALYSIS OF WINDS. 719 



The valley of the Rhone is another outlet for the air flowing towards the 

 Provence. Here nearly all winds take a N. or S. direction, i. e., flow in the 

 direction of the valley ; but the first are largely in excess, as is shown by the 

 observations in Eastern France (from 45°-46° N.), and especially at Orange, where 

 62 per cent, of all the winds in summer and 54 per cent, in winter come from the 

 N.i (See Plate 9.) 



In the country further east the Alps seems to form a boundary between the pre- 

 vailing W. and S. W. winds to the north, and N. winds to the south, at least in 

 autumn and winter. This is caused, as has been previously said, by the relatively 

 higher pressure of the country around the Alps, and the relatively low pressure on the 

 Mediterranean. Unfortunately very few results of observations in Northern Italy 

 could be obtained in the libraries of Washington, though many are known to exist. 

 Besides, the observations of Milan and some other stations were reduced to the four 

 components (N., E., S., W.), so that percentages calculated from them would not be 

 immediately comparable to the observations of other places where eight directions 

 are given. 



The winds of Parma seem to show what takes place in the lowlands of N. Italy. 

 In winter the prevailing wind is N. W., in summer nearly all directions are repre- 

 sented equally. Bologna seems to have monsoon winds W. (from the land) in 

 winter, and E. (from the Adriatic) in summer. (See Plate 9.) 



The stations of Switzerland S. of the Alps (Lugano, Bellinzona, Mendrisio) have 

 largely prevailing N. winds, and a very great number of calms. 



The admirable system of meteorological observations begun in Switzerland in 

 1864 has already given much information as to the winds on mountains and high 

 passes. Of these, the observations on isolated mountains are most valuable, as on 

 high passes the direction is often very much influenced by the surrounding 

 mountains. 



The direction on high peaks is generally the same as in the surrounding country, 

 but the character is much more marked, one or two directions prevailing to a 

 greater extent than at the foot of the mountains, and the intervening winds being 

 less numerous. 



The Chaumont is situated in the Jura Chain just above Neuchatel. Here we 

 have already a slight prevalence of northerly winds in summer, which is continued 

 in the valley of the Rhone, in Southern France. In the winter S. W. winds 

 prevail to a very great extent on the Chaumont, much more than in Neuchatel and 

 in Western Switzerland generally. 



The winds of N. Switzerland are very like those of Germany, that is, westerly 

 at all seasons, as shown on Plate 9, but rather S. W. in winter, and W. N. W. in 

 summer. This is also the case on two isolated mountains of this region, the 

 Uetliberg (near Zurich) and Eigi-Kulm, only the proportion of westerly wind is 

 much greater on the mountains. 



Chaumont, Uetliberg, and even Rigi-Kulm, are scarcely high enough to have 



' Count Gasparin, Founiet, and Ch. Martens were among the first to draw attention to this 

 prevalence of northerly winds in Southern France. 



