Smithsonian Report, 1955. — Spencer Jones 



Plate 1 



Earth 



# 





1. Sunspot group of April 1947, with tiie earth shown to scale. This is the largest sunspot 

 group to appear since the Greenwich sunspot observations were comnienceci in 1874. (Royal 

 Greenwich Observatory.) 



2. Bright eruption on the sun, February 22, 1926, S li. ?i(> ni. This eruption was followed 

 by a great magnetic storm commencing Februar)' 23, 16 h. 30 m. (Kod^ikanal Observa- 

 tory.) 



