246 STRAITS METEOROLOGY. 



"105. Rainfall — Heights of Rivers and Lakes. — In 1872 Meldrum 

 of the Mauritius Observatory brought forward evidence showing 

 that the rainfalls at Mauritius, Adelaide, and Brisbane were, on the 

 whole, greater in years of maximum than in years of minimum sun- 

 spots. Shortly afterwards it was shown by Lockyer (Nature, 

 December 12, 1872) that the same law was observable in the rain- 

 falls at the Cape of Good Hope and Madras. 



" Meldrtjm has since found that the law holds for a great num- 

 ber of stations, including eighteen out of twenty-two European 

 observatories, with an average of thirty years' observations for 

 each. The results are exhibited in the following table : — 



[ Here follows a list of 22 cities with observations for an aver- 

 age of 30 years, shewing in 18 cities excess and in 4 cities defect of 

 rain in the periodical " sun-spot" years.] 



" It would, however, appear from the observations of Governor 

 Ha.wso:n x that the rainfall in Barbados forms an exception to this 

 rule, being greatest about the times of minimum sun-spots. 



" 106. Gustav Wex in 1873 l showed that the recorded depth of 

 water in the rivers Elbe, Rhine, Oder, Danube and Vistula for the 

 six sun-spot periods from 1800 to 18G7 was greater at times of 

 maximum than at times of minimum sun-spot frequeiu^. These 

 conclusions have since been confirmed by Professor Eritz. 2 



"Quite recently Stewart (Proc. Lit. and Phil. Soc. of Manchester. 

 1882) has treated the evidence given by Eritz as regards the Elbe 

 and Seine in the following manner. He divides each sun period, 

 without regard to its exact length, into twelve portions, and puts 

 together the recorded river heights corresponding in time to 

 similar portions of consecutive sun periods. He finds by this 

 means residual differences from the average representing the same 

 law, whether we take the whole or either half of all the recorded 

 observations, and whether we take the Elbe or the Seine. The 



1 Engemevr Zeitschi'ift, 1873. 



2 Ueber die Beziebungen cler SonnenflecTten Periode zu den Magnetiachen 

 mid, Meteorologischen Erseheiinnigrn dor Erde. Haarlem, 1878. 



