Marvels of the Universe 



)85 



light any colour is sup- 

 pressed, a mixture of the 

 remainder is called a com- 

 plementary colour, for it is 

 the colour required to re- 

 store the sensation of white 

 light. Blue and yellow 

 mixed produce green, and 

 accordingly green is the 

 complementar}' to red. In 

 like manner, a mixture 

 of red and yellow pro- 

 duces orange, which is 

 complementary to blue. 

 Similarly, indigo is com- 

 plementary to yellow, and 



yellowish-green to violet. It may be convenient to have these facts put in tabular form, and 



slightly varied in detail, thus : 



Red is complementary to ...... . Bluish-Green. 



COLOURED STARS. 



Colour is most frequently to be found 

 in double or multiple stars ^vhich. — 



COLOURED .STARS 



— althousli showing a white single light 



to the naked eye, can under a powerful 

 telescope — 



Sky-Blue. 

 Violet-Blue. 

 Violet. 

 Pink. 



Orange ........ 



Yellow 



Greenish- Yellow . . . 



Green ........ 



The situation of things is really this : that any two colours which are complementary as above 

 give, when mixed in proper proportions on a rapidty revolving disc, a composite tint which is 

 almost white. 



We are now in a position to carry the matter farther as regards Double Stars, the two 

 members of which exhibit complementary colours. In such cases, the larger Star is usually of a 

 ruddy, or at any rate, orange hue, and the smaller one blue or green, or something between the two, 

 say, bluish-green or greenish-blue, somewhat according to the fancy of the observer. If comple- 

 mentary- colours are noticed in the components of a Double Star which are of very unequal size, 

 the circumstance may be attributed often or mainly to the effect of contrast ; yet it is permissible to 



suppose that sometimes 

 the colour seen is actually 

 the intrinsic colour of the 

 Star. 



The number of Stars 

 which exhibit various gra- 

 dations of colour between 

 crimson, on the one hand, 

 and only yellowish on the 

 other, are very numerous 

 indeed. They may be 

 counted by hundreds, not 

 to say thousands, and are 

 scattered over the whole 

 heavens, and are of vari- 

 ous sizes from the first 

 to the eighth or ninth 



COLOURED STARS. 



— be separated inlo two, three, or more 

 distinct stars of different hues, and in 

 many casea — 



COLOURED STARS. 



— these colourings are complementary 

 one with another, so that a red star will 

 combine with a green to produce the effect 

 of while lifiht. 



