1882.] Photographic Spectrum of Comet (Wells) 1, 1882. 149 



tograph to resolve them into lines. These places of greater brightness 

 can be traced beyond the border of the continuous spectrum on the 

 side which corresponds to the coma of the comet on the side next the 

 sun. The light from this part of the comet gave a very much fainter 

 continuous spectrum, for on the photographic plate it appears to be 

 almost wholly resolved by the prism into these bright groups. One 

 or two fainter groups are suspected to be present, but they are too 

 indistinct to admit of measurement. 



The five stronger bright groups are too faint at the commencement 

 and ending of each group to permit of more than a measurement of 

 the estimated brightest part of each bright space. 



The positions of these brightest parts are — 



