Comet a 1890 and the Nebula G.C. 4058. 219 



and the blue band was brighter than the citron. The latter was the 

 most difficult to measure. The hydrocarbon band near \ 431 was 

 not visible. The continuous spectrum extended from about D to a 

 little beyond A, 474. 



May 22. Nucleus of comet not nearly so central as last night. 

 Formation of tail apparently commencing. No very obvious change 

 in the spectrum. The fluting at 517 was possibly a little brighter, 

 but there was no change in the citron fluting. The flutings still 

 extended over the whole comet. Still a fair amount of continuous 

 spectrum, to a large extent masking the carbon flutings. 



May 23. Form and spectrum of comet not distinguishable from 

 last night. The nucleus is possibly still less central. 



May 27. The appearance and spectrum of the comet were precisely 

 the same as on May 23. It seemed a little fainter, but this was 

 probably due to moonlight and a slight haze. 



June 6. The comet was much brighter than on previous occasions. 

 The tail was longer and was turned from the Sun. There was less 

 continuous spectrum than before, so that the bright flutings were 

 more distinct, and a narrower slit could be used for comparisons. 

 The coincidences with the carbon flutings were still quite perfect 

 with the dispersion employed. There was no shift in the citron 

 band. 



June 9. The comet did not appear any fainter, notwithstanding 

 the published ephemeris. There was still less continuous spectrum 

 than on June 6. The 517 fluting now very clearly seen. No change 

 in the positions of the bands. 



G. C. 4058. This is a white nebula in Draco, apparently some- 

 what similar to the Andromeda Nebula. The spectrum, according to 

 Dr. Huggins, is continuous. The observations showed the spectrum 

 to be irregularly continuous, and remarkably similar in appearance to 

 th.3 spectrum of Comet Brooks. The brightest part was found by 

 direct comparison to be coincident with the carbon fluting \ 517. 

 No definite measures were made of any other brightnesses, but 517 

 is certainly present, and is not much less distinct than in the 

 spectrum of the comet. The fluting appeared relatively a little 

 brighter than in the Andromeda Nebula. The length of continuous 

 spectrum was about equal to that of the comet. 



All the observations were made with the 10-inch refractor by 

 Mr. Fowler. The similarity of the spectra of the comet .and the 

 nebula on June 9 was confirmed by Mr. Baxandall. 



The observations emphasise what I pointed out to the Society two 

 years ago, namely, that the spectra of nebulae and comets are similar 

 both at aphelion and during the approach to perihelion. The facts 

 being so, we are justified in considering, therefore, that nebulas which 

 present to us a carbon spectrum are more condensed than those which 



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