THE Fl'EL OF THE SUX. 'Jo 



worked out tlic necessity of the gaseous eruptions, and their 

 action in effecting an interchange of solar and general atmos- 

 pheric matter, as the means of maintaining the solar light and 

 heat, with no idea of proceeding further with the problem, 

 when the announcement that the prominences were not merely 

 unquestionable solar appendages, but were actually upheaved 

 mountains of glowing hydrogen, suddenly and unexpectedly 

 suggested their identity with my required atmospheric up- 

 heavals. It is true that their observed magnitude far exceeded 

 my theoretical anticipations, and in this respect I have made 

 some a posteriori adaptations, especially with the aid of a 

 clearer understanding of the laws of dissociation which almost 

 simultaneously became attainable. 



In like manner, the necessity of the solid ejections present- 

 ed themselves before I knew anything of the recently discovered 

 details of the coronal phenomena when I had merely read of 

 a luminous halo which had been seen around the sun, and, 

 relying upon Mr. Lockyer, vaguely supposed it to be an effect 

 of atmospheric illumination. I inferred that streams of solid 

 particles must be pouring from the sun, and showering back 

 again, but had no idea that such streams and showers were 

 actually visible until I was rather startled on learning that the 

 corona, instead of being, as I had loosely supposed, a mere 

 uniform filmy halo, had been described by Mr. De la Rue, in 

 his Bakerian Lecture on the Eclipse of 1860, as " softening off 

 with very irregular outline, and sending off some long streams," 

 etc. I was then living on the sides of a Welsh mountain far 

 away from public libraries, and being no astronomer, my own 

 books kept me better acquainted with the current progress of 

 experimental than with astronomical science. 



Even when " The Fuel of the Sun" was published I knew 

 nothing of the American observations of the quadrangular 

 figure of the corona, or should certainly have then quoted 

 them, nor of the fact revealed by the Eclipse of December, 

 1870, that, " wherever on the solar disk a large group of 

 prominences was seen on Mr. Seabroke's map, there a corre- 

 sponding bulging out of the corona was chronicled on Professor 

 Watson's drawing ; and at the positions where no prominences 

 presented themselves, there the bright portions of the corona 

 extended to the smallest distances from the sun's linib ; and 

 that Mr. Brother's photographs all show the corona extending 

 much farther toward the west than toward the east, the west 

 being " the region richest in solar prominences." I am sorry 



