22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



more ol)late corona might have a difterential eft'ect on the intensity 

 of the ultra-violet light reaching the separate hemispheres. 



Returning again to Dr. Dobson's results, he finds much the same 

 values in both hemispheres. He now has an observer in New 

 Zealand (1928).^ He states^ that he finds very little connection of 

 his observations with the sun-spot cycle, and that little apparently in a 

 reverse sense from that clearly indicated by the writer's results. He 

 obtains an altitude for his ozone layer from the Hartley band at 30 to 

 40 km., whereas Cabannes and Dufay get an altitude from the 



I 



N pomt; 



N point" 



Mar.7 



5LPT.8 



Huggin's band of 40 to 50 km. One might hazard the suggestion 

 that it is not beyond possibility that the band used by Dr. Dobson 

 corresponds to such a state of the molecule that only ozone formed 

 by ultra-violet light is in the proper molecular state to efifect absorp- 

 tion ; whereas the band in the yellow is due to a molecular state which 

 measures absorption due to ozone formed by either process. It will 

 presently be seen how such supposition as to two layers of ozone is in 

 line with the conclusions drawn from magnetic data relating to two 

 separate strata, the lower of which is assumed to be due to ultra-violet 

 light. 



Observatory, 51, 381, 1928. 

 ' Proc. Roy. Soc. 114 A, 532, 1927. 



