78 IOWA ACADEMY OF SCIENCES. 



During the year 1893 very many magnificent groups 

 were present on the sun; especial mention of the group of 

 February 5th to ISth in south latitude is noted as being 

 very intricate with numerous nuclei and interlacing penum- 

 bra; several fine auroras were also visible during this 

 period. 



The next large group made the transit from March 17th 

 to 30th, and developed into a fine train of spots. Two 

 large and active groups were in south latitude from April 

 27th to May 14th, one containing curiously shaped umbrge 

 and penumbras, with many luminous "bridges" crossing 

 the umbrae. The other group was still more active and 

 interesting, undergoing continuous changes from day to 

 day — small spots increasing to large nuclear spots, then 

 forming a train, afterwards a stream, finally becoming 

 single spots again. A large quadruple cluster of spots was 

 visible in June, a fine train of large spots in Juh', and the 

 disc continued to be spotted with many beautiful groups 

 and trains, — unusual displays of the Northern lights were 

 coincident with these. August was especially rich in fine 

 g:roups, which were easily visible to the naked eye. A 

 remarkable group appeared at the east limb on the 2d, 

 which by the following day had developed unusual activity 

 and increased enormously with auroral manifestations in 

 the evening; two days later the group still consisted of two 

 huge spots with scorpion-like nucleus in one spot, and was 

 a superb object; aurora continued for several evenings. On 

 the 8th fully 100 spots in fourteen groups dotted the sun- 

 spot zones and the climax of the sunspot curve was full of 

 groups of tremendous magnitude, with immense areas of 

 penumbrEe, enclosing umbrae of all forms — helical, wing- 

 shaped, triangular, and fimbriated, cruciform, pitcher- 

 shaped, tassel-like, eel-shaped, etc. 



Many other interesting groups continued till November 

 and December, when large composite groups were present, 

 fully rivaling in extent, the giant disturbance of February, 

 1892. 



