On the Solar Eclipse of 9th September, 1885. 889 



absorbed by the passing moon, and the coruscations of light 

 about its limbs. Unfortunately man has not, like insects, com- 

 pound eyes, enabling him to see at the same time both what is 

 behind and what is before. If the ordinary beams of the corona 

 did not produce the bands of light, did the exceptional quivering 

 rays, which appeared just before and after totality, above and below 

 the sun, and referred to early in this paper, do so? Or were the 

 prominences or protuberances the cause of these mysterious 

 bands ? I mean, was their appearance in some way spectro- 

 scopic, as well as spectral ? 



" We must remember that, for spectroscopic effect, we had 

 virtually an isolated and thin pencil of light from the sun, and 

 possibly from the prominences only, immediately before and 

 after totality, and, furthermore, that the sun - prominence 

 spectrum consists of bright lines; and perhaps something in- 

 vening between the sun and the earth — atmosphere, meteoric 

 bodies, vapour — operated as a prism to produce refraction (just 

 as rain does to produce the rainbow), or as a fine grating to pro- 

 duce diffraction. I think that the dark colour between the 

 bands of hght was the same as the general colour of things at 

 the time ; in other words, not that the bands of light were 

 alternated with dark bands, but that they were simply light 

 bands on a dark surface. Otherwise, the dark bands might 

 suggest the innumerable dark lines of the spectrum, rendered 

 visible in some mysterious way by the exceptional circumstances, 

 with intervening bands only approximately and relatively light, 

 but really of various colours, or in some way divested of colour. 

 But then the dark lines of the spectrum, though innumerable, 

 are very irregularly disposed ; whereas the dark lines which we 

 saw, if they were dark lines at all, were very evenly and 

 regularly distributed, and alternated invariably with light bands, 

 and the hght and dark seemed to be exactly of the same breadth. 

 My knowledge of the spectrum and its laws is very small, too 

 small to permit of my doing more than suggest questions, 

 which perhaps may very easily be disposed of. 



" If these suppositions be unentertainable, was the pheno- 

 menon atmospheric in origin ? Evaporation hi the hot sun- 

 shine can often, as is well known, be seen most distinctly, the 

 moisture, as it ascends from the ground, being rendered clearly 

 visible by its quivering motion to the height of several feet. It 

 can also be seen in long and strong streaks through a mass of 

 distant clouds in certain conditions of weather. There was a 

 rapid change of temperature about the time of totality, but it 

 was towards a lower point, not towards a higher, and the lost 

 degrees were not recovered till nearly half-past eight o'clock, as 

 has been already explained. The quivering motion of evapora- 

 tion occurs during exceptional heat, when the ground is, through 

 recent rains, moist. The circumstances do not seem to be at all 



