METEOROLOGY. 329 



open, free space, and fairly represents the wind of the northern base of 

 the Alps. In general lie finds for Beruo the southwest and north to 

 be the most frequent wimls, while ibr Sautis they are the southwest 

 and west. The total movement of the wind is, for Berne 2,500, but 

 for the Santis 22,000 kilometers during the month. The strongest winds 

 for Berne are southwest, north, and northeast, but for the Siintis 

 southwest and west. The altitudes for the two stations are, for Berne, 

 570 meters; for the Santis anemometer, 2,508 meters, the anemometer 

 cups being t meters above the summit of the mountain. The diurnal ve- 

 locity of the wind is very great at Berne, having a maximum velocity 

 of 10.0 kilometers per hour between 1 and 2 p. m., and a minimum of 0.1 

 between 4 and 5 A. M., but for the Siintis summit we have a maximum 

 38.1 between 3 and 4 A. m., and a minimum 28.2 between 8 and 10 A. 

 M., and again between 2 and 3 P. M. {Z. O. G. M., xviii, p. 410.) 



243. The first year of observations on the summit of the Santis (alti- 

 tude 2,407 meters) are publivshed by Hann, from which we see that the 

 greatest wind velocity occurred at 9 p. m. on the average of the year, 

 the mean value being 1.60 of the scale on the Wild tablet anemometer, 

 the maximum being 2.2 in March and the minimum 1.2 in June; the 

 average lowest wind force was 4.10 at 1 P. m., the highest being 2.1 in 

 November and the minimum being 0.8 in June. {Z. 0. O. M., xviii, p. 

 479.) 



244. Stevenson has from some observations at heights less than 200 

 feet endeavored to obtain the rate of increase of the wind with the alti- 

 tude. He finds that the following formulae represent his observations : 



For wind velocity y~'\I^' ^^^^ pressure -p-=CT 

 where the small letters refer to the lower station and the large letters 

 to the higher; the velocities are expressed in miles per hour, the press- 

 ures in pounds per square foot, and the altitudes in feet. By means of 

 these formula) it should become possible for meteorologists to reduce all 

 observed wind velocities and pressures to a uniform standard altitude. 



245. [It would seem that one of the most important steps to be taken 

 in the near future, inonler to render the study of daily weather maps a 

 more precise scientific matter, consists in the correction of anemometer 

 readings for instrumental and local peculiarities and their reduction to 

 a uniform altitude above the surface of the ground ; similarly the tem- 

 perature and moisture observations so far as they relate to the moving 

 mass of air should be reduced to a uniform elevation ; as regards rain- 

 fall the correction for local and instrumental peculiarities seems almost 

 hopeless, but is none the less desirable ; the reduction to a uniform alti- 

 tude, however, is a much simpler matter.] {Z. 0. 0. i)/., xviii, p. 319.) 



246. E. D. Ar<!hibald, of London, has undertaken an investigation into 

 the velocity of the wind as afl't'cted by the altitude above ground, and 

 has extended Mr. Stevenson's experiments (which terminated with a 



