1871.] The Eclipse of Last December. 235 



"I desired Captain Maclear," writes Father Perry, "to 

 observe with a small direct-vision Browning spectroscope, 

 attached to a 4-inch telescope." " Immediately totality 

 commenced, the ordinary solar spectrum was replaced by a 

 faint diffused light, and bright lines." " There were no dark 

 lines — that is to say, none of those lines which are present 

 in the solar spectrum. When the spectroscope was directed 

 to a distance of about 8' from the edge of the moon's 

 disc, the same lines remained visible. The centre of the 

 moon was then tried, and the bright lines were still seen, 

 but only half as strong as before." * 



But let us turn to Professor Young's account of his own 

 observations, and those made by his fellow-workers. 



First of all, and perhaps scarcely inferior in interest to 

 anything learned during the recent eclipse, there is Professor 

 Young's observation of the reversal of all the dark lines of 

 the solar spectrum close by the limb at the commencement 

 of totality. I had, at page 295 of " The Sun," ventured 

 to express my belief that the Fraunhofer dark ^ines would 

 be found to have their birth-place here (and not, as surmised 

 by Mr. Lockyer, beneath the visible limits of the photosphere) ; 

 and it was, therefore, with some pleasure that I read the 

 following confirmation of my views on this point : — " With 

 the slit of Professor Young's spectroscope placed tangentially," 

 writes Professor Langley, " at the moment of obscuration, 

 and for one or two seconds later, the field of the instrument 

 was filled with bright lines. As far as could be judged during 

 this brief interval, every non-atmospheric line of the visible 

 spectrum showed bright ; an interesting observation con- 

 firmed by Mr. Pye." " From the concurrence of these quite 

 independent observations, we seem to be justified in assuming 

 the probable existence of an envelope surrounding the 

 photosphere and beneath the chromosphere, usually so called, 

 whose thickness must be limited to two or three seconds of 

 arc, and which gives a discontinuous spectrum consisting 

 of all or nearly all the ordinary lines, showing them, that is 

 to say, bright on a dark field." On this point Professor Young 

 remarks, that "the sudden reversal into brightness and 

 colour of the countless dark lines of the spectrum at the 

 commencement of totality, and their gradual dying out, was 



* It will be noticed that this result exactly accords with my anticipations in 

 the above quoted passage from the Monthly Notices of the Royal Astronomical 

 Society. No stronger proof can be required of the fact that the illumination in 

 our air is not the " sunlight" of the atmospheric glare theory, than this circum- 

 stance, that towards the moon's disc, where we have this illumination pure 

 and simple, we get a spectrum of bright lines (instead of a faint solar 

 spectrum). 



