TWO YEARS LATER. 33 



vation, and urged them to grant a sum for the 

 construction of a suitable spectroscope. With the 

 usual generosity of the Koyal Society, such a sum was 

 placed at Mr. Lockyer's disposal. The problem of 

 making a spectroscope which would adequately lengthen 

 out the solar spectrum was successfully solved by Mr. 

 Browning, the eminent scientific optician ; and, finally, 

 some two months after the eclipse of 1868 Mr. Lockyer 

 tried the powers of the instrument thus placed in his 

 possession. As already mentioned, the bright-coloured 

 linfeTof the prominences were distinctly seen with the 

 new spectroscope ; and although Janssen's similar 

 observations had been made nearly two months earlier, 

 no question rests on the independent nature of Mr. 

 Lockyer's observation. Indeed, so successfully had 

 Mr. Browning mastered the optical difficulties of the 

 problem, that no doubt whatever can exist that Mr. 

 Lockyer would have been successful, altogether inde- 

 pendently of the information afforded him, in the ac- 

 tual case, by the eclipse observations of August 1868. 



But now let us see the position in which spectro- 

 scopists stood. The new mode of observing the pro- 

 minences presented no special difficulties at least, 

 what difficulties there were referred to the optician 

 rather than the astronomer, (riven a telescope of 

 adequate power, armed with a spectroscope spreading 

 out sufficiently the rainbow-tinted streak which forms 

 the solar spectrum, and it became at once possible for 

 any tolerably well-trained observer to make a series of 

 such researches as, twenty years ago, no man of science 



III. D 



