222 



NATURE 



{July 7, 1 88 



near together, and of a bluish-green ; the third was much 

 fainter and with very httle apparent colour, but easily 

 seen as a bright line. I called these " three green lines,'' 

 as that was the general appearance in the field of \iew, 

 and I had no intention of fixing the positions of the lines. 

 The words however require explanation, as they would 

 naturally be understood as restricting the bands to a 

 definite part of the spectrum. On July i, shortly before 

 midnight, I examined the position of these hnes more 

 carefully, keeping the slit sufficiently open to secure a 

 fairly strong continuous spectrum from the nucleus in the 

 centre of the field, whilst the bright lines extended along 

 the whole length of the slit. I could then see clearly that 

 the two strong bands were in the green and blue, and 

 that the fainter line was almost at the extremity of the 

 more refrangible end of the spectrum visible in the small 

 spectroscope used, and would therefore be situated in the 

 violet or purple. 



The comet on the night of July i was very mu:h 

 diminished in brilliancy, but at midnight it could still be 

 traced by aid of a binocular through at least 7°. The 

 nucleus shone as a 2 '3 magnitude star, and under a con- 

 siderable magnifying power it was found to have lost most 

 of the interesting features of June 27. The double enve- 

 lope, so well defined in outline a few days previous, had 

 disappeared, and there now remained only the bright 

 nucleus bounded towards the tail by two arcs, one on 

 either side of the centre, from which those rays seemed 

 to spring which moved slightly in the direction of the 

 sun, and then bent round to help in forming the tail. A 

 mass of light surrounded the head, but this faded away 

 gradually into a nebulous outline. The light from the t^il 

 diminished very rapidly as the distance from the head 

 increased, ^sub Polo transit of the centre of the nuclcu.^ 

 gave, for July i, iih. 50m. 7s. G.M.T., the following 

 position uncorrected for parallax and aberration : — 

 R-.-V. 6h. 20m. SJs.-ji ; N. Decl. 70° 14' 53"7. 



S. J. Perry 



Stonyhurst Observatory, Whalley, July 4 



I INCLOSE three drawings of the comet made on 



hydrocarbon spectrum very distinctly. No bands were 

 seen in the tail, but only in the imme i;ate proximity of 

 the nucleus. On the 29th the comet was much fainter; 



t e bright jet had disappeared, giving place to a fan, of 

 w'.iich the left-hand>ide was the brighter. A small star was 

 s.en through the co'aia, a, which the comet rapidly passed. 



the 27th, 29th, and 30th ult. On the 27th the bright je: 

 extending from the nucleus was very plain,'and gave t'.ic 



Last night (30th) the fan-shaped projection had n.ir- 

 roweJ coasi-!erablv and a pareatly extended farther from 

 the nucleus. ' ' A. Percv Smith 



Tem_ le O jservatcry, Ru^by, July 1 



