SOLAR ECLIPSE OF JANUARY 3, I908 — ABBOT 47 



As for the attractive hypothesis of electrical discharge lumines- 

 cence, like that of the aurora, one hesitates to recommend recourse 

 to a source so little known. So far as known, too, this hypothesis, 

 like the others, has difficulty to reckon with the character of the 

 photographic coronal spectrum. 



The cause of the corona-brightness seems very difficult to decide, 

 in view of conflicting considerations ; but in the judgment of the 

 writer the hypothesis that it is mainly due to the reflection of ordi- 

 nary sun rays, but modified by radiation of incandescence and per- 

 haps also luminescence, seems most tenable. 



In conclusion, it is a pleasure to acknowledge the great aid 

 afforded by the director and staff of the Lick Observatory Expedi- 

 tion ; the conscientious and able work of my assistant, Mr. Moore ; 

 the intelligent and faithful assistance rendered on the day of the 

 eclipse by Chief Yeoman Chase, of the Annapolis; the aid furnished 

 by the owners and manager of Flint Island, and the uniformly cor- 

 dial and courteous attentions of Governor Moore and the officers of 

 the Annapolis, and of many others during the time when the expedi- 

 tion was in transit. 



