METEOROLOGY AND ALLIED SUBJECTS. 



289 



formula (Zeitschrift Bd. IX, 1874, page 198,) for the distribution of 

 moisture, and its excellent argument is shown by the following table: 



{Z. 0. 0. M., XVI, 1881, p. 170.) 



Stelling has published an elaborate memoir on the annual periodicity 

 of evaporation at Eussian stations. The observations forming the basis 

 of his work have been uniformly made with Wild's "Weighing Evapori- 

 meter," and the installation of these instruments at the various stations 

 have been carried out with great uniformity ; moreover, the stations 

 represent a very great variety of climates and the records extend through 

 periods of three to seven years, beginning with 1872. Among the gen- 

 eral results we notice that the annual minimum everywhere occurs with 

 the minimum temperature of January ; the maximum depends, however, 

 upon the Continental location, with its resulting winds, as well as upon 

 temperature. The relation between evaporation and rainfall is perhaps 

 best seen by comparison between observations at St. Petersburg and 

 Taschkent, while the variations due to slight variations in the immedi- 

 ate surroundings can be seen by comparing Pavlosk with St. Peters- 

 burg, twelve miles distant, or the stations at the observatory and in 

 the city of Taschkent, as shown in the following table : 



station. 



Tears. 



Evapora- 

 tion. 



Mean tem- 

 perature. 



Total 

 rain. 



Petersburg 



Pavlosk 



Taschkent observatory 

 Taschkent City 



187»-79 

 1878-79 

 1878 

 1878 



280 



188 



1,416 



667 



4°. 4 

 30.8 

 140.8 

 13°. 1 



603 

 654 

 409 

 393 



{Z. 0. O. M., 1881, p. 119.) 



R6nou has made some important studies upon the cloudiness in 

 Europe. By combining his own observations with those of others, he 

 finds the daily curve of cloudiness for Paris; then from a general sur- 

 vey of diurnal periodicity he finds a minimum at 10 or 11 p. m., and 

 a maximum at 1 or 2 p. m. in Paris, with a second maximum in the early 

 morning hours, this latter being particularly well marked in the United 

 States. The annual curve for Paris shows a maximum in December, 

 and two minima in April and September, respectively ; but this curve 

 S. Mis. 109 19 



