ASTRONOMY. 389 



at the same distance from the moon's limb. The details of this will be 

 given and discussed at a future time. 



"I studied also the rings of Respighi. The rings did not appear uni- 

 form about the moon's linrb, but presented peculiarities of structure, 

 which will be especially discussed in their relation to the question of 

 ' the Frauenhofer lines. 



"I studied also polarization, but devoted to it only a few moments, 

 using the excellent biquartz polariscope of Prazmowski. The polariza- 

 tion was very well defined, and possessed characteristics already rec- 

 ognized. 



"Before the observations, I made a preliminary examination of the 

 corona with the naked eye, and with an excellent telescope by Praz- 

 mowski. This examination was for the purpose of guiding me in the 

 subsequent observations. 



"'All these studies — stud}' of shape, spectrum analyses, Respighi's 

 rings, polarization — were combined with a view of solving the question 

 of extra-solar cosmic substances. We think that the discovery of the 

 complete Frauenhofer spectrum in that of the corona considerably ad- 

 vances this question. 



" Photography. — Two great instruments, containing eight cameras, had 

 been prepared for studying the question of intra-mercurial planets, and 

 that of the shape and extension of the corona. With regard to heavenly 

 bodies in the vicinity of the sun, these photographs will require a minute 

 examination ; but with respect to the corona, it can be said that the 

 great power of several of the lenses used — that of eight inches (0.21 m.) 

 and that of six inches (0.16 m.) — and also the length of exposure, per- 

 mitted us to prove tbat the corona has an extension very much greater 

 than that shown by optical examination, either with the naked eye or 

 in my telescope. 



" Several of our large photographs of the corona have great distinct- 

 ness. They show important details of structure which ought to be dis- 

 cussed. The shape of the corona was absolutely constant during the 

 whole duration of totality." 



The reports of Messrs. Tacchini, Palisa, and Trouvelot are not given, 

 but are alluded to in the discussions of the results of the observations 

 which next follow. Mr. Janssen regards it quite improbable that any 

 intra-mercurial planets exist, on account of the negative testimony given 

 by Mr. Palisa, combined with that of Professor Holden of the American 

 party. Mr. Trouvelot's conclusion is less decisive, but the observer 

 wished to re examine the region of the sky before coming to a final con- 

 clusion.* 



*Mr. Trouvelot observed, near the close of totality, a star which he describes as 

 " bright, and of a pronounced red color ; " but, by some misunderstanding, its true po- 

 sition was not recorded by the special attachments to the circles above described. 

 Its position, therefore, cannot be determined, nor the question of its identification be 

 positively settled. The observer announces {Compte* revdus, September 17) that he has 

 re-examined the region, and finds no star of the corresponding magnitude and color 



