XV. On the photographic spectrum of comet (Wells) 1,1882

On the evening of Wednesday, May 31, I obtained a photograph of the spectrum of this comet with an exposure of one hour and a quarter. A spectrum of a Ursæ Majoris was taken through the other half of the slit, on the plate, for comparison. The photograph shows a strong continuous spectrum extending from about F to a little beyond H. In this continuous spectrum I am not able to distinguish the Fraunhofer lines. In this comet therefore, at this time, the original light giving a continuous spectrum must have been much stronger relatively to the sunlight reflected than was the case in the comet of last year. It should be stated that the greater faintness of the present comet made it necessary to use a more open slit, which would cause the Fraunhofer lines to be less distinct; but the lines G, H, and K are to be clearly seen in the star’s spectrum taken under the same conditions.