'J'he Systematic Motions of Sun-spots. 



Angular Veloc ties of Maxima I and II far Différent Zon3s of Latitude, 

 deduced from Carrington's Observations. 



Fig. 2. 



-r.2.0 



ira I'l "7 14?6 14.6 



1-4 °4 14°3 14°2 14° 1 14°0 

 Angular Velocity 



l.'5°9 i;i°8 i;r7 13?6 



Carrington's angular velocity given in the last column of Table 

 V is derived from his formula for the angular velocity, ^=865'+ 

 165' sin'/. 



4. Similarly I have examined Spörer's observations. The 

 data for our discussion of the spots as observed by him have been 

 taken from the same source as that from which he deduced his 

 expression, 8°. 548 + 5°. 798 cos /Î, for the daily motion of the sun- 

 spots in different solar latitudes, namely his " Beobachtungen der 

 Sonnenflecken zu Anclam."^'^ The observations comprise the 

 period 1861-71, the number of the spots whose angular velocities 

 are computed being 264. To increase this number, I have 

 extended the discussion of his observations^"^ up to the end of the 

 year 1878. So the total number of spots employed became 334. 

 Similarly to the others, Table VII and Plate III were prepared. 

 It is unfortunate that none of the curves in Plate III show 

 so striking a secondary maximum as in the previously con- 

 sidered cases, although there is no doubt that each curve 



(1) Publicationen. der Astronomischen Gesellschaft. XIII 1874 pp. 139—146. 



(2) Publicationen des Astro-physikalis:heu Observatoriums zii Potsdam. Xr. 5. p. 06. 



