206 



EXPERIMENT STATION RECORD. 



METEOKOLOGY. 



On the diurnal variation of rainfall, A . Anciot ( Gompt. Rend., 122 

 {lsu6)j Xo. 2-1, pp. Ii09-lill). — Suimiiariziug- the results of daily obser- 

 vations at Paris during G years (L890-'05), in 8 3-hour periods, tlie fol- 

 lowiuii' fi inures are obtained, showing- the thousandths of the total rainfall 

 duriu<;- the respective periods : 



liaiufull duriny different parts of the day in summer and winter. 



The average for the whole day is 125. In summer the rainfall falls 

 below this average during 5 ]>eriods, or 15 hours out of the 24, from 

 9 p. m. to noon. In winter, on the other hand, the rainfall exceeds 125 

 in only 2 periods, 3 to 9 a. m. — that is, at the time of lowest temperature 

 and greatest relative humidity. The most marked variations occurred 

 in May and September. During April, October, and November the 

 daily vaiiations were not appreciable. Since the conditions in summer 

 and winter are almost diametrically opposed, the averages for the year 

 possess no significance. 



From observations on the frequency of rainfall during the same period, 

 it appears that the probability of rain for each hour of the day during 

 the summer is 75 out of 1,000. This rises to 104 between 3 and C p. m., 

 and is about 71 for the rest of the (Iny. In winter the average proba- 

 bility is 93, rising to 103 between 3 and C p. in. and 120 between C and 

 9, remaining constant at about 8G during the rest of the day. The 

 intensity and freipiency of rainfall were found to follow the same rule. 



Observations w^ith actinometers on Mont Blanc to determine 

 the solar constant, J. Vallot (Rev. >Svient., ser. i, G [1896), No. 2, p. 

 53). — The results ol>tained by the author in 1887 with the absolute acti- 

 nometer of Ville and in 1S91 with the mercury actinometer of Crova 

 while differing widely from the results of other observers agree closely 

 with each other, although obtained by totally difterent instruments aud 

 calculated by two distinct methods. The solar constant is equal to the 

 quantity of heat observed at a given station increased by the amount 

 absorbed by the atmosphere. 



Monthly Weather Revie^v ( U. S. Dept. Agr., Weather Bureau, 

 Monthly Weather Rcvieic, 2J [1895), No. 13, pp. VII, 489-501, charts 5).— 

 This number contains the title-pages, table of contents, list of corrections 

 and additions, and index for volume 23 (1895) of the Review, aud an 

 annual summary of meteorological observations during 1895, "based 

 upon data received from about 3,000 stations occupied by regular and 

 voluntary observers of the Weather Bureau, Canadian data received by 



