62 



E. WALTER MAUNDER, F.R.A.S., ON 



zones would be in evidence — the zone on both sides of the equator 

 vv'hich had been first seen, and a zone, the centre of which was 

 about latitude 23° or 24° in the northern hemisphere, and a 

 similar one in the southern. As time went on, spots would 

 increase in number and size in the two 2ones last named, and 

 would diminish in the equatorial zone, until the latter was left 

 quite free from them, and only the two higher latitude zones 

 would show any spots. In these, hoAvever, spots would multiply, 

 but with an increasing tendency to form in lower latitudes. The 

 greatest display of sunspots would take place when the mean 

 latitudes of the spotted areas north and south would lie about 

 13° or 14° from the equator. After this, the spots would diminish 

 both in size and numbers ; their distance also from the equator 

 would decrease, until in eleven years or thereabouts from 

 the first observations practically all spots would be found 

 within a single zone extending about 10° from the equator in both 

 directions. This peculiarity of sunspots is of great interest and 

 im2)ortance, as it seems to suggest that the spots must be due 

 to causes lying within the body of the sun itself, and not to any 

 outward influence of planets or combination of planets. 



Table I. — Change of the Mean Spotted Area and of its Mean 

 Distance from the Equator during the Progress of the Solar Cycle. 



Cycle 1879-1889. 



Cycle 1889-1902. 



Cycle 1901-1913. 



Year. 



Mean 

 daily 



snn?pot 

 area. 



^Mean 

 distance 



from 

 equator. 



Year. 



>rean 

 dally 

 sun-p <t 

 area. 



ilean 

 distance 



from 

 equator. 



Year. 



Slean 

 daily 

 .sunsp.jt 

 area. 



:Mean 

 distance 



from 

 jequator. 



1879 



35 



Deg. 

 23-19 



1889 



53 



Dag. 

 22 -43 



1901 



5 



Beg. 

 20-41 



1880 



440 



19-64 



1890 



99 



21-99 



1902 



46 



23-87 



1881 



681 



18-30 



1891 



569 



20-31 



1903 



340 



19-94 



1882 



1000 



17-81 



1892 



1214 



18-39 



1904 



488 



16-57 



1883 



1154 



13-06 



1893 



1464 



14-49 



1905 



1191 



13-10 



1884 



1079 



11-26 



1894 



1282 



14-18 



1906 



778 



13-99 



1885 



807 



11-77 



1895 



974 



13-54 



1907 



1082 



12-12 



1886 



381 



10-38 



1896 



543 



14-33 



1908 



697 



10-38 



1887 



179 



8-44 



1897 



514 



7-96 



1909 



692 



9-71 



1888 



89 



7-39 



1898 



375 



10-49 



1910 



264 



10-53 



1889 



26 



6-39 



1899 



111 



9-54 



1911 



64 



6-49 









1900 



75 



7-74 



1912 



37 



8-06 









1901 



24 



8-49 



1913 



1 



4-43 









1902 



16 



8-66 









