v.,, 



Dl{. C. CHfcEE: SOME PHENOMENA OF StJNSPOTS 



at timrs corresponding to the several groups of subsequent days, naturally become 

 less the longer the period of years dealt with. The fact that the commencing months 

 of both 1890 and 1901 were all very quiet is also to the advantage of the 11 -year 

 group, as compared with the 6-year group. Still, I should have preferred, but for 

 considerations of time, to have included quiet as well as disturbed day data for the 

 1 1 years, employing the Astronomer Royal's quiet days for the former. 



The data for the previous associated pulse, and the first, second, and third 

 subsequent associated pulses in Table V. are very fairly smooth ; but those for the 

 fourth associated subsequent pulse seem unduly affected by " accidental " phenomena, 

 which depress the entry for day 108 and raise that for day 110. The eleven years 

 were dealt with in four groups 



(A) Surispot minimum years, 1890, 1899, and 1900; 



(B) Sunspot maximum years, 1892, 1893, and 1894 ; 



(C) Highly disturbed years, 1891, 1895, and 1896 ; 



(D) Other years, 1897 and 1898. 



The largest " character " figure for the five days 107 to 111 occurred on day 111 

 in group (A) and day 110 in group (B), but on day 107 in groups (C) and (D) ; while 

 the lowest figure occurred on day 108 in group (A), and on day 111 in groups (C) 

 and (D). Considering this variability, much weight cannot be attached to details in 

 the results for the fourth associated subsequent pulse. The fact, however, that the 

 figures for all five days 107 to 111 are so decidedly in excess of the normal seems 

 clear evidence that this pulse is by no means negligible. 



The primary pulse in Table V. shows the two characteristics noted in the discussion 

 of fig. 2. The third day prior to the representative disturbed day is decidedly quieter 

 than the average day. The rise to the maximum in the primary pulse is considerably 

 more rapid than the subsequent fall. This a-symmetry is also clearly shown by the 

 first and second associated subsequent pulses. 



The ratio borne by the excess of the maximum " character " figure for the primary 

 pulse over the normal to the corresponding excesses for the associated pulses are as 

 follows : 



Primary pulse. 



First associated. 



Previous. 



0-323 



Subsequent. 



Second associated 

 subsequent. 



Third associated 

 subsequent. 



0-298 



0-310 



0-182 



0-11C 



These ratios are fairly similar to those derived in 12 from the combined disturbed 

 and quiet day data of the 6-year period. In the present case, however, we have 



