262 SCIENCE PROGRESS. 



PHOTOGRAPHIC RESULTS DURING A SOLAR ECLIPSE, 1893. 



A method which was first employed by Respighi and 

 myself during the eclipse of 1871, was employed on a 

 large scale and with great effect during the eclipse of 1893. 

 The light proceeding from the luminous ring round the 

 dark moon was made to give us a series of rings, represent- 

 ing each bright line seen by the ordinary method on a 

 photographic plate. The observers this time were stationed 

 in West Africa and in Brazil. The African station was 

 up one of the rivers, not very far away from the town of 

 Bathurst. The Brazilian station was near Para Curu. The 

 same instrument which was previously referred to as used for 

 obtaining photographs of the stars was sent to the African 

 station in order that photographs of the eclipse of the sun 

 might be taken on exactly the same scale as the photo- 

 graphs of the stars had been, so that the stellar and solar 

 records in the photographs might be compared. The results 

 obtained by Messrs. Fowler and Shackleton, who were in 

 charge of the instruments at the two stations, will be gathered 

 from the accompanying diagrams, Figs. 10 and 11. 



We get more or less complete rings when we are deal- 

 ing with an extended arc of the chromosphere, or lines of 

 dots when any small part of it is being subjected to a dis- 

 turbance which increases the temperature and, possibly, 

 the numbers of the different vapours present. 



The efficiency of this method of work with the dis- 

 persion employed turns out to be simply marvellous, and in 

 securing such valuable and permanent records as these, we 

 have done very much better than if we had contented our- 

 selves with the style of observations that I have referred to 

 as having been made in 1871. 



As was expected the comparison between solar and 

 stellar records thus rendered possible enabled a very great 

 advance to be made. 



On examining these eclipse records, we find that we 

 have to do exactly with those unknown lines which had 

 already been photographed in the stars and in the nebulas. 



As was to be expected we, of course, deal with the lines 



