322 



SCIEMTIFIC RECORD FOR 1884. 



normal value. The wonderful agreement of these variations with the va- 

 riations of Wolf's sun-spot numbers shows that we have here to do with 

 some general feature connecting the earth and sun. the inflections of the 

 rain-curve following those of the sun-spot by an interval of about one 



year. 



Eremzer'a variability of rain in Europe. 



(D. M. Z., p. 93.) 



221. G. J. Symons, of London, gives an important discussion of the 

 variation in annual rainfall for the years 1830 to 1881 in England. The 

 mean of nine stations is reduced to annual percentages, the extreme range 

 of which is from 71 per cent, in 1854, up to 136 per cent, in 1852. From 

 1853 to 1859, inclusive, the rainfall was below the average; from 1875 to 

 1881, it was decidedly above the average. Hann remarks that this dry 

 period prevailed also on the northern side of the Alps, while the wet pe- 

 riod prevailed over the whole of Western and Central Europe. The very 

 dry period that prevailed in Hungary, 3861 to 18GC, was not prominent 

 in England. In general, the average variability of English rainfall is 

 about 14 per cent, of its mean quantity, but it amounts to about 40 per 

 cent, each half century. The wet and dry years apparently arrange 

 themselves in series of ten And twelve years respectively ; thus the wet 

 years are 1836, 1848, 1860, 1372 ; the dry years are 1834, 1844, 1854, 

 1864, and 1874. (Z. 0. G. M., xviii, p. 387.) 



222. F. Augustin has studied the rainfall at Prague, especially as to 

 its daily periodicity, having at his disposal twenty years' observations 

 with a self recording rain-gauge; he finds it impossible to give the mean 

 annual periodicity, especially because of the difficulty of measuring the 

 snow in winter time, and the loss of occasional very heavy rainfalls in 

 saramer time, but the daily maxima and minima stand forth very clearly. 

 As regards quantity of rainfall, the i)rincipal maximum occurs between 

 4 and 5 p. M., shortly after the temperature maximum. A second max- 

 imum occurs between 9 and 10 p. m. ; a third maximum between 9 and 

 10 A. M. The principal minimum occurs about 4 A. M., a second min- 

 imum between 7 and 8 p. m., and a third minimum between 11 A. m. and 

 noon. With regard to the frequency of rain, there are also three maxima 

 and three minima, as follows: The j)rincipal maximum, 7 to 8 p. m.; 

 the secondary maxima, between 8 and 9 A. M., and between 2 and 3 p. m.; 

 the principal minimum, between 2 and 3 a.m.; the secondary minima, 

 about noon and between 4 and 5 p. m. 



