1876.] On Rainfall in connexion with Sun-spots. 379 



Astacus fluviatilis. Trapezia pectinata. 



Squilla. ferruginea. 



Porcellana rugosa. Pilurnnus. 



longicomis. Melia tessellata. 



Galathea. Carpelodes rugipes. 



Pagurus tibicen. Actinurus setifer. 



elegans. Xantho Lamarckii. 



Bernhardus. Aetata obesa. 



Clibinarus. Thia ? 



Trichia. Liomera. 



G-elasimus. Pirimella ? 



Cyclograpsus. Thalamita. 



Libinia. Ackelous. 



Mensetheus. Euriphia. 



Stenorhynchus. Thalassina. 



Mithrax. Carcinocystus, n. g. 



III. " On a Secular Variation in the Rainfall in connexion with 

 the Secular Variation in amount of Sun-spots." By Charles 

 Meldrum, M.A., Director of the Mauritius Observatory. 

 Communicated by B. Stewart, F.R.S., Professor of Natural 

 Philosophy, Owens College, Manchester. 



(Abstract.) 



In this paper the author suras up the principal results obtained by his 

 investigations as follows : — 



(1.) Taking for the individual years of maximum and minimum sun- 

 spot those given in par. 4 *, it is found that the rainfall in the maxima 

 exceeds the rainfall in the minima years in each country or district, and 

 therefore in all taken collectively, the mean annual excess for Great 

 Britain being 1*94, for the continent of Europe 3*64, for America 5'17, 

 for India 8*98, and for Australia 6*23 inches, which gives a me'an 

 excess of 5*19 inches. In Great Britain the rainfall in seven of the 

 nine years of maximum sun-spot exceeds the rainfall in the corresponding 

 seven out of nine years of minimum sun-spot; on the continent of 

 Europe six out of seven maxima years are similarly favourable ; in 

 America five out of six are favourable, in India four out of six, and in 

 Australia two out of three. 



A comparison of the mean rainfall of all the stations taken collectively 

 gives an average annual excess of 7*01 inches in favour of the years of 

 maximum sun-spot, and seven of the nine maxima years are favourable. 



(2.) It is thus seen that the excess is not owing to abnormal and 

 casual heavy falls in one or two years of maximum sun-spot, but that it 



* Namely :— Years of maximum sun-spot, 1729, 1739, 1750, 1761, 1770, 1778, 

 1789, 1804, 1817, 1829, 1837, 1848, 1860, 1871 ; years of minimum sun-spot, 1733, 

 1743, 1756, 1766, 1776, 1785, 1798, 1811, 1824, 1834, 1843, 1856, 1867. 



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