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Meteorology. — Oscillations of the solar actlrltij and lh<' rj'nnate 

 by Dr. C. Eastox. (Coiiiiminicated by Dr. C. H. Wind). 



The parallelism between the oscillations in the "solar activity" 

 and the variations of the magnetic elements of the earth is certain, 

 and a similar parallelism is suspected for some other terrestrial 

 plienomena. The meteorological elements, however, iiavc always 

 seemed to be subject to so many ditferent perturbations, as to obscure 

 the corresponding parallelism, which most probably does exist in 

 this case also. BRrcKXER lias considered this point in his well-known 

 investigations on oscillations of climate ^), but he only reached a negative 

 result. It is true that K()PPKN and Nordmann *), restricting themselves 

 to tropical countries, liave established a parallelism with the 11-year 

 period of the solar spots for the period from 1840 to 1900, and 

 Köppen's curve also shows this parallelism tolerably well for the 

 southern temperate zone, while for the noi'lhern temperate zone 

 Langley's bolometric observations') give us a right to expect much 

 from his method for the future. For the non-tropical zones on the 

 whole, however, (and therefore also for the earth as a whole) the 

 disturbino' influence of terrestrial causes would seem to be such that 

 the oscillations produced by a cosmical cause are entirely obscured. 



The reason of this is apparent. The direct influence of the solar 

 radiation can only be visible in the general temperature-cui-ve for 

 regions Avliere the difference between the seasons is neither very 

 large, nor their change very irregular. This reason is already 

 sufficient to explain why Bruckner's so-called "ten.ij)era(ure-curve 

 for the whole earth" [on which the observations in the northern 

 temperate zone have a preponderating influence] differs so widely 

 from the curve representing Rudolf Wolf's -'Relativzahle]!" for the 

 sunspots. It appeared to me therefore that this question must be 

 considered from a different point of ^'iew. 



Dr. W. J. Ö. LocKYER has recently published an investigation ") 

 in which he reaches the result that Bruckner's period of 35 years 

 in the climate is also found in the irregularities of the 11-year period 

 of solar activity. He tries to show this by comparing the variable 

 quantity M—m (which represents the interval of time between a 

 minimum of sunspots and the following maximum), with Bruckner's 



1) E. Bruckner. Klimaschwankungen seit 1700., Geogr. Abli. IV, 2 (1890). 

 ■~) W. Koppen. Zeits. Oesterr. Ges. f. Met. YIII, XV, XVI. —Gh. Nordmann. Gompies 

 rendus T. 136, p. 1047 (1903). 



3) S. P. Langley. Aslroph. Journal XIX, p. 305 (1904). 

 *) W. J. S. LocKYEK. Proc. Roy. Society, LXVIII (1901). 



