276 Star Colours. 



they induce our eyes to see. Thus, red and green will each 

 look brighter and more decided when in simultaneous view. 

 This source of colour would be sufficient to account for some 

 stars appearing different from their real hues ; but it may be 

 eliminated by a bar or wire that keeps one star out of view 

 while the other is seen. By such means the position and real 

 character of star colours is assured, and we ask what do they 

 proceed from ? 



This question will be better answered when we have made 

 out a little more concerning our own sun. At present it seems 

 as if the light of the sun and stars emanated from intensely 

 heated vapours holding solid particles, hot enough to be lumi- 

 nous, in suspension. The carbon particles in common gas, as 

 in the gaseous products of a oil lamp, have a yellowish tinge ; 

 molten silver is greenish, and the lime light tinged with blue. 

 The atmosphere which probably surrounds the luminous matter 

 of our sun, or of other suns, obstruct certain rays, as the dark 

 lines of the spectrum show ; but with this exception we pro- 

 bably see sunlight and starlight pretty much as it is emitted 

 by the luminous matter, that is, within the limits of our sight, 

 for we cannot perceive rays that exceed or fall short of a cer- 

 tain velocity in their vibration, or of a certain refrangibility. 



An accumulation of facts, some of which have been recorded 

 in the papers of Mr. Webb, and others of the same kind, which 

 we leave for his abler pen to describe, have given a new interest 

 to coloured stars, by showing that they are liable to alterations 

 and changes, some of which appear periodical. The observa- 

 tion and due registration of these changes will afford a useful 

 and delightful occupation for amateurs, and with a view to 

 give precision to this class of inquirers, Admiral Smyth has 

 proposed, in a privately issued work, called Sidereal Chromatics, 

 a certain scale for comparison. He gives four tints, each 

 diminishing in intensity, of red, orange, yellow, green, blue, 

 and purple, leaving whites to be described, in the order of their 

 purity and brightness, by the terms — 1, creamy white; 2, 

 silvery white; 3, pearl white; 4, pale white. A suggestion 

 from Admiral Smyth is sure to be of value in itself, and to be 

 well received by all astronomical observers, and we apprehend 

 the only doubt that will arise will concern the method of em- 

 ploying his chromatic scale, and in this matter, with great 

 deference for his opinion, we must profess a little disagree- 

 ment, as we think it will be necessary to employ qualifying 

 adjectives to a greater extent than he suggests. The more 

 most coloured stars' are looked at, the more will most 

 observers be convinced that they are neither a simple tint of a 

 primary or of a secondary colour, and in many cases the hue is 

 of so much complexity as to render it difficult to say what it is. 



