LIGHT AND COLOUR 



lamp is yellower than that of the sun, while 

 glowing coal shines red. Even when the light 

 coming from the source is white, we know that 

 different things on which it falls have different 

 colours to our eyes. Light, it is clear, brings 

 us colour, and the world would be a very dull 

 place without colour. The grass is green, the 

 sky is blue, a house is red, yellow or grey ; this 

 all seems quite simple. But as usual, when we 

 begin to think a little more, we find that things 

 are not so simple as we are at first sight inclined 

 to believe. The sky is not blue at sunset, at 

 any rate it is not all blue ; it is quite as often 

 grey as blue at sunrise. The grass is green in 

 the day-time, but it may seem black at night, 

 and almost purple at sunset. Hills may look 

 grey at sunrise, green at mid-day, blue in the 

 evening, and brown and green if we walk up to 

 them. What colour are they really ? I myself 

 have twice seen, once in Egypt and once in 

 Norway, a range of hills that were not very far 

 off, look as crimson as any rose. A haystack is 

 usually yellow or brown ; in the glow of a sun- 

 set I have seen one look purple, and have also 

 seen pictures in which artists have had the cou- 

 rage and sense to paint them so. 



Perhaps we may begin to think that colour 

 is a very uncertain thing ; but if a rose is red one 

 day when seen near at hand in ordinary day-light, 

 we are sure that it will be red the next day, and 

 pretty sure that the same rose-bush will have red 



(53) 



