526 



H. MOHN. METEOROLOGY. 



[NORW. POL. EXP. 



PRECIPITATION. 



For each month of the drift of the Fram, and for each observation-hour, 

 the sum has been taken of the numbers of cases in which rain, snow, sleet 

 or hail have been noted. These sums, divided by the whole number of 

 observations made at the respective hour in the month, give a fraction repre- 

 senting the probability of precipitation for that hour. The following Table 

 gives the diurnal period of this probability in thousandths, or per mille. For 

 the months from October, 1893, to February, 1894, in which the observations 

 were made only every fourth hour, the numbers for the intermediate hours 

 have been interpolated. The numbers are (smoothed) deviations from the 

 diurnal means. 



PROBABILITY OF PRECIPITATION. THE DIURNAL PERIOD. 



