536 



SCIENCE 



[N. S. Vol. XLV. No. 1169 



our sun led to the drawing out of solar ma- 

 terials in two opposing spiral branches ; and 

 that these materials in part, or for the most 

 part, remained outside of the sun and in 



revolution about it, the whole composing a 

 spiral nebula. The materials in the two 

 branches of the spiral, the authors say, 

 eventually combined into certain central 



The Great Star Cluster in Hercules, photographed bv Eitehey with the 60-iiieh reflect- 

 ing telescope of the Mount Wilson Solar Observatory. 



