1885.] on the Solar Corona. 207 



graphs taken in England where there was no eclipse, with those taken 

 at Caroline Island of the undoubtedly true corona during the eclipse. 

 On the day of the eclipse the weather was bad in this country, but 

 plates were taken before the eclipse, and others taken later on. These 

 plates were j)laced in the hands of Mr. Wesley, who had had great 

 experience in making drawings from the photograjihs taken during 

 former eclipses. Mr. Wesley drew from the plates before he had any 

 information of the results obtained at Caroline Island, and he was 

 therefore wholly without bias in the drawings which he made from 

 them. [Photographs of Mr. Wesley's drawings were projected on the 

 screen, and then a copy of the Caroline Island eclipse photograph. 

 The general resemblance was unmistakable, but the identity of the 

 object photographed in England and at Caroline Island was placed 

 beyond doubt by a remarkably formed rift on the east of the north 

 jDole of the sun. This rift, slightly modified in form, was to be seen 

 in a plate taken about a solar rotation period before the eclipse, and 

 also on a plate taken about the same time after the eclipse. The 

 general permanence of this great rift certainly extended over some 

 months, but no information is given as to whether the corona rotates 

 with the sun. For from the times at which the plates were taken, one 

 about a rotation period before and the other a rotation period after 

 the eclipse, it is obvious the rift might have gone round with the 

 sun, but there is no positive evidence on this point.*] 



As the comparison of the English plates with those taken at 

 Caroline Island possesses great interest, I think it well to put on 

 record here a letter written by Mr. Lawrence to Professor Stoke?:, 

 dated September 14, 1883:— 



" Dr. Huggins called upon Mr. Woods this morning and showed us 

 the drawings Mr. Wesley has made of his coronas. He told us that 

 he particularly did not wish to see our negatives, but that he would 

 like us to compare his results with ours. We did so, and found that 

 some of the strongly marked details could be made out on his drawings, 

 a rift near the north pole being especially noticeable ; this was in a 

 photograj)h taken on April 3, in which the detail of the northern 

 hemisphere is best shown, while the detail of our southern hemi- 

 sphere most resembles the photograph taken on June 6 ; in fact, 

 our negatives seem to hold an intermediate position. Afterwards I 

 went with Dr. Huggins and Mr. Woods to Burlington House to see 

 the negatives. The outline and distribution of light in the inner 

 corona of April 3 is very similar to that on our plate which had the 

 shortest exposure; the outer corona is, however, I think, hidden by 

 atmospheric glare. As a result of the comparison, I should say that 

 Dr. Huggins's coronas are certainly genuine as far as 8' from the 

 limb." 



Though the plates which were obtained during the summer of 1883 

 appeared to be satisfactory to the extent of showing that there could 



* See Plates XI. and XIa, British Association Eeport, 1883, p. 348. 



