180 Mr. J. N. Lockyer on the recent Eclipse of the Sun [Jan. 27, 



There is a diameter approximately corresponding to the solar axis, near 

 the extremities of which the radiance upon the photographs is a minimum, 

 whereas the coronal beams in these directions were especially marked 

 during a great part of the total obscuration. The coronal beams stood in 

 no apparent relation to the protuberances, whereas the aureole seen upon 

 the photographs is most marked in their immediate vicinity ; indeed the 

 great protuberance, at 230 : to 245 c , seems to have formed a southern 

 limit to the radiance on the western side, while a sharp northern limit is 

 seen on all the photographs at about 350", the intermediate arc being 

 thickly studded with protuberances which the moon displayed at the close 

 of totality. The exquisite masses of floeculent light on the following limbs 

 are upon the two sides of that curious prominence at 93~, which at first 

 resembled an ear of corn, as you have said, but which, in the later pictures 

 after it had been more occulted, and its southern branch thus rendered 

 more conspicuous, was like a pair of antelope's horns, to which some ob- 

 servers compare it. Whatever of this aureole is shown upon the photo- 

 graphs was occulted or displayed by the lunar motion, precisely as the 

 protuberances were. The variations in the form of the corona, on the 

 other hand, did not seem to be dependent in any degree upon the moon's 

 motion. The singular and elegant structural indication in the special 

 aggregations of light on the eastern side may be of high value in guiding 

 to a further knowledge of the chromosphere. They are manifest in all 

 the photographs by your parties which I have seen, but are especially 

 marked in those of shortest exposure, such as the first one at Ottumwa. 

 In some of the later views they may be detected on the other side of the 

 sun, though less distinct ; but the very irregular and jagged outline of the 

 chromosphere, as described by Janssen and Lockyer, is exhibited in per- 

 fection/' 



The second point is also referred to in the same letter. I think the 

 American photographs afford evidence that certain appearances in parts of 

 Mr.De La Rue's photographs, which represent the chromosphere as billowy 

 on its under side, are really due to some action either of the moon's 

 surface or of a possible rare lunar atmosphere ; so that it is not desirable to 

 confound these effects with others that might be due to a possible suspen- 

 sion of the chromosphere in a transparent atmosphere, if only a section of 

 the chromosphere were photographed. 



Dr. Gould writes : — * You will observe that some of the brighter, petal- 

 like flocculi of light have produced apparent indentations in the moon's 

 limb at their base, like those at the bases of the Drotuberances. These 

 indentations are evidently due to specular reflection from the moon's sur- 

 face, as I stated to the American Association at Salem last month. Had 

 any doubt existed in my mind previously, it would have been removed by 

 an inspection of the photographs." 



Where the chromosphere is so uniform a light that the actinic effect on 

 the plate is pretty nearly equal, the base of the chromosphere is absolutely 



