METEOROLOGY. 323 



The intensity of tho rainfall or the quantity per hour changes very 

 nearly as the total quantity; the probability of rain follows the curve 

 of rain frequency. {Z. 0. G. M., xvii, p. 243.) 



223. F. Seeland, of Klageufurt, has studied the daily record of the 

 height of water in the wells fed by subterranean springs at Klageufurt 

 during the five years 1878 to 1882; the height of water is, of course, a 

 general result of the rainfall of the whole of the surrounding basin, 

 which extends from northwest to southeast. All the springs in this basin 

 show similar phenomena; the lowest average reading prevailed in 1878; 

 the highest in 1879. Comparison with the rainfall at one station, 

 Klageufurt, scarcely gives any satisfactory basis for unraveling the 

 complicated phenomenon. The highest rainfall occurred in 1787 and 

 the least in 1881. [Z. 0. G. J/., xviii, p. 339.) 



224. H. F. Blanlbrd, director of the Meteorological Office in India, 

 from a study of the conuection between snowfall in the Himalaya and 

 the subsequent dry winds of Northern India, draws the following con- 

 clusions : 



1. A remarkably heavy and especially a kite snowfall in the Northwest 

 Himalayas is followed by a long i^eriod of drought on tlie plains of 

 Northwest and Western India. 



2. A rich winter and spring precipitation at the stations of the North- 

 western Himalayas is followed in sixteen cases out of eighteen by a de- 

 ficient summer rain on the plains of Northwest India, and vice versa. 



3. The west winds that are characteristic as abnormal during droughts 

 in west and north India are identical in character with the normal 

 winds of the regular dry season, and appear to be fed by descending 

 currents from the Northwest Himalayas and possibly from the mount- 

 ains on the west. 



4. It is an ordinary well known phenomenon of the winter months 

 that a fall of rain and snow in the Northwest Himalayas is directly fol- 

 lowed by a wave of high pressure that progresses from the western hills 

 toward the east, accompanied by a cool northwest wind. 



5. The conclusion that seems to follow is that an unusual extension of 

 thesnow-coveringin the Northwest Himalaya acts upon the higher levels 

 in summer like the ordinary fall of snow and rain in the lower regions 

 of the Himalayas in the winter time, and favors the formation of the 

 dry northwest winds on the plain of Western India. 



6. That the dependence of the dry winds upon the Himalaya snow- 

 fall offers a criterion for the prediction of the probability of a drought 

 in Northwestern and Western India. {Z. 0. G. M., xix, p. 378, and Na- 

 ture, XXX, p. 40.) 



225. H. F. Blanford, in studying the theory of the winter rains in 

 Northern India, concludes that the aqueous vapor evaporated from the 

 earth's surface diiiiises gradually upwards in the quiet atmosphere of 

 Northern India and reaches an altitude favoring the condensation into 

 cloud. When once in this way a moderately thick bank of cloud has 



