( 374 ) 



a pnorl liaviiio,- regard lo <lio lualei'ial on whicli (ho (•iir\'cs arc hascd. 

 I only Avisli lo show that (he .aencral cliaracter ol" llie leini)era(ürc 

 curve is the same as tliat of the curve of sohir activity. It is 

 important to remark that the mean cnr\'e B is more similar to A 

 than D. The deviations in position of the variations of temperature 

 relatively lo those of solar activity seem to be at least partly system- 

 atic. On comparing the temperature curve and the solar curve in 

 the separate eleven-year periods we must however not only consider 

 the greater or smaller nund)er of spots, hut also another phenomenon 

 (which, it is true, is certainly connected with the abundance of spots) 

 viz. the deviations of the minimum and maximum from Ihejiormal. 



This phenomenon appears already vaguely in the correspondence 

 of the values M — m with the number of cold winters, to which 

 I referred in the beginning of this j)aper. It is shown more clearly 

 how^ever in tig. Ill on the plate. For the last 17 periods of 11 years 

 the dotted line represents the acceleration ( — ) or i-etardation (-|-) 

 (expressed in years) of the observed solar minima and maxima, 

 comparetl with the normal period of 11.13 years. The corresponding 

 cold-coefficients are represented h\ the continuous line having four 

 ditFercnt ordinates corrcs|ionding to the foni- degrees {A, B, C, I)) of 

 cold. On the whole we lind that to an acceleration of the solar pei'iod 

 corresponds a more intense cold, and to a retardation a greater heat. 



This rule also holds for the individual ])eriods, ])rovided the 

 deviations are large. Oombining this result with the distribution of 

 cold-coefficients over the phases of one and the same eleven-year period 

 which was mentioned just now, and with the larger oscillations found 

 above, we find the following rnle, which is presented as a hypothesis : 



On the whole the oscillation o f t e r r e s t r i a 1 tem- 

 perature is accelerated r e 1 a t i \' e 1 }' to the e I e \' e n- 

 y e a r \^ a r i a t i o n o f s o 1 a r a c t i \' i t y in the colder part 

 f t h e larger period, and retarded i n t h e h o 1 1 e r 

 par t. In cold 11-year periods the centre of gravity of cold is 

 near the minimnm of sunspots, and often there are very cold years 

 preceding the minimum; in warm periods it is situated near the 

 maximum or thereaftei'; in periods of intermediate character it falls 

 between the minimum and the maximum. 



For the individual cases we find that, in cases of considerable 

 retardation or acceleration of the solar minimnm or maximum, the 

 centre of gravity of cold tends to be exceptionally retarded or 

 accelerated. If the minimum of a sunspot period occurs very early 

 and the subsequent maximum is retarded, the cold period also is 

 largely extended. 



