IOWA ACADEMY OF SCIENCES. 85 



northern hemisphere of the sun was the least disturbed, 

 being nearly one-fourth less than the southern. 



While the sun was now rapidly approaching the period 

 of solar activity when the spots are smaller, fewer and 

 more transitory; still a few interesting groups were 

 observed this year. On March 15th and 26th fairly large 

 spots entered the disc and made the transit; the latter one 

 was unique in that the major axis of its umbra seemed to 

 have a cyclonic motion, which nearly completed a revolu- 

 tion around its common center. 



The next important spot, and, in fact, the largest of the 

 year, entered at the east limb on June 23d — an oval spot, 

 with "bridged" umbra and much spectroscopic activity on 

 the 26th; the spot was increasing on the 27th, its umbra 

 being a deep purple color, and having near its center an 

 intensely black "hole'' or nucleus; it still increased with 

 branching umbra and penumbra, and later was breaking 

 up, not to reappear at a subsequent rotation. A somewhat 

 large normal spot passed across the disc during the first 

 half of July, after which date a period of prolonged quies- 

 cence set in, lasting during the rest of the year, with occa- 

 sional small transitory spots in September and October. 



1900. 



The average number of groups, spots and facuhce con- 

 tinued to diminish during the present year, and the total 

 number of spotless days increased to 134 or 52A percent of 

 the number of days of observation. 



Periods of absolute tranquility occurred in every month 

 of the year. 



The principal spots observed were in March, April, May 

 and October. The March group appeared suddenly, and 

 during several rotations the region was active; the disturb- 

 ance finally disappeared during the first week in May. The 

 telescope was dismounted and shipped to Wadesboro, North 

 Carolina, shortly after May 16th, where the writer succes- 

 sively observed the total eclipse of the sun on May 28th. 

 Observations were not again resumed regularly until June 

 3d. Mainly small and sporadic spots were noted during 



