ON SUNSrOT.S ASI) TF.RItESTRIAL PIIKNOMK.NA. 



4o3 



fact wouM tlirow j»nivo doubts on tlio real it v of tho connection, had it 

 not l)Ocn pointed out that just nt, that time tho sunspot curvo was very 

 iriCfj^uJar. It has been shown by Kooppon tliafc tho niaxiinum of temporn- 

 tniro in 177i* and tho niininiuni in \7^'* occuitcmI when it oupht to havo 

 douo under tho supposition of a rejjfuhir course of sunspot activity. It is 

 nselcsfi to specuhito how such a state of thiu<,'s coukl liavo been brought 

 sihout, wo can only wait the further development of oventH. 



TAr-i.K I. 



ii 



Maxiiiuiin of 'I'l'ini ii'iatiirc 



TroplcH 



ls;!:ii 



1SI2S 



1 8,-. (•7 



Kctropienl 

 Kc^^ions 



1H2.-.-S 

 18:JC2 



(1S(1S.7) 



Siinspofs . 

 Tcmperiitur.' 



TAHf.K II. 



I 'j*rn|iic.s 



(^ Mctiupical llcgioua 



G-:t 



10'3 



CO 

 7() 



■l(» 



:i-o 

 2;t 



;it) 



(11 



8G 



4-2 



Hahn has paid special attention to tho summers and winters which aro 

 remarkable either by an exceptionally high or an exceptionally low tem- 

 perature, and he has shown that, on tho whole, both hot summers and 

 warm winters occur near times of minimum sunspot fre(|ncncy, while cold 

 winters and summers both occur most frequently directly after a time of 

 great solar activity. But tho facts do not show themselves sufliciently 

 regular as to warrant at pT-esent any prediction on tho general nature of 

 any particular summer or winter. 



The results obtained by Koeppeu have been confirmed in many ways. 

 Stone' has shown that the mean temperature at the Cape of Good Hope 

 shows a decided tendency to imitate the curve of sunspot frequency, and in 

 such a way that to a great number of spr ♦^^s corresponds a minimum of 

 temperature. Piazzi Smyth' tells us in the same way that the thermo- 

 meters sunk into the rocks of Calton Hill show a decided period of eleven 

 years. Tho maxima of temperature occurred in 1846, 6; 1858, G; and 

 18G8, r. These times fall shortly after the minima of spots, which took 

 place m 1843, 5 ; 18-56, ; and 1867, 2. It is to be observed that thermo- 

 meters introduced into the ground are specially fitted for tho examination 

 of long period oscillations. The rate at which the amplitude of an oscil- 

 liition decreases with the depth, increases quickly with the length of the 

 period, and the deeper thermometers are introduced into the ground, the 

 more will all short period inequalities bo sifted out, and only the longer 

 ones will remain. The amplitude of long oscillations will of course be 

 teduoed also, and there are li' ts, therefore, depending on the senaitive- 



Prw. Royal Soc, xix., 38U. 



Artr. Obs, Ed. xiv, 



1 



