Star Colours. 277 



Now in such, cases a simple reference to tints, such as " red 

 3, blue 4," would, we think, be insufficient. If, for example, 

 a number of observers, with different telescopes, assign a 

 certain greenishness to the blue companion of Albireo, the fact 

 should be recorded, and ' ' blue 2" would require to be supple- 

 mented by an appropriate adjective. Admiral Smyth's tints 

 appear to us admirably chosen for the purpose he has in view, 

 and we should like to see them imitated in coloured solutions, 

 or in coloured glass, which we think would be more convenient 

 that flat tints on paper, as the light seen through transparent 

 bodies affords a nearer approach to the luminous effect of stars. 



We are glad to see by citations, which Admiral Smyth 

 makes from Dawes, and other eminent authorities, that Home 

 and Thornth waiters "aplanatic eye-pieces" are appreciated 

 for these inquiries. We spoke highly of them on their first 

 appearance, and prolonged trials have confirmed our good 

 opinion. 



There are many topics of importance in Admiral Smyth's 

 work — which is a reprint, with additions, from his former publica- 

 tions — on which we abstain from commenting now, because we 

 know they are engaging the attention of Mr. Webb, who will 

 bring them forward in due time. We shall now only record our 

 thanks to the Admiral for his new and important aid to the study 

 of double stars, and conclude by wishing our telescopic sub- 

 scribers to examine Gov. Caroli, and send us an account of the 

 colours of the component stars, stating the size of the object- 

 glass, sort of eye-piece, and power employed. Admiral Smyth 

 gives a number of estimates of these colours, as they seemed 

 to different eyes, and finally describes them himself as, A, pale 

 reddish white; D, lilac: or in his scale, A, red 4, purple 3. We 

 confess we should not have called it red, and shall be much 

 interested in knowing and publishing what other observers 

 see. 



