PRESIDENTIAL ADDRESS, B.A. 1871. 183 



different gases in the Sun's photosphere, spots, 

 chromosphere, and chromospheric prominences, 

 and his observations of the varying spectra 

 presented by the same substance as it moves from 

 one position to another in the Sun's atmosphere 

 and his interpretations of these observations, 

 according to the laboratory results of Franklancl 

 and himself, go far towards confirming the convic- 

 tion that in a few years all the marvels of the Sun 

 will be dynamically explained according to known 

 properties of matter. 



During six or eight precious minutes of time, 

 spectroscopes have been applied to the solar 

 atmosphere and to the corona seen round the dark 

 disk of the Moon eclipsing the Sun. Some of the 

 wonderful results of such observations, made in 

 India on the occasion of the eclipse of August 

 1868, were described by Professor Stokes in a 

 previous address. Valuable results have, through 

 the liberal assistance given by the British and 

 American Governments, been obtained also from 

 the total eclipse of last December, notwithstanding 

 a generally unfavourable condition of weather. It 



