THE PAINTER AND THE MOON 81 



as an object at a greater distance than the high moon or 

 sun. This is due to the long vista of arching clouds above 

 and of stretching landscape or sea below when the sun or 

 moon is looked at as it appears on or near the horizon. 

 The illusion is aided by the dulness of the low moon and 

 the brightness (supposed nearness) of the high moon. 

 Being judged of (unconsciously) as further off than the 

 high moon, the low moon is estimated as of larger size 

 although of the same size. This is, I believe, the correct 

 explanation of the illusion. When one gazes upwards to 

 the sky, a small insect slowly flying across the line of 

 sight sometimes is "judged of" as a huge bird an eagle 

 or a vulture since we refer it to a distance at which birds 

 fly and not to the shorter distance to which insects 

 approach us. It seems that it would be possible for the 

 painter, by carefully studying actual natural facts and 

 introducing their presentation into his picture, to produce 

 the impression of greater distance, and therefore of size, into 

 a quarter-inch moon placed near the horizon. He is not 

 compelled for want of other means to " cut the difficulty " 

 and paint a falsely inflated moon which shall brutally and by 

 measurement call up the illusion of increased size. I repro- 

 duce here (Plate VI) an interesting drawing which shows 

 how such illusions of size can be produced. It is none the 

 worse for my purpose because it is an advertisement by the 

 well-known firm who have kindly lent it to me. The three 

 figures represented in black are all of the same height, yet 

 the furthest one appears to be much taller and bigger alto- 

 gether than the middle one, and the middle one than the 

 nearest. This result is obtained by suggesting distance as 

 separating the right-hand figure from us, whilst giving it 

 exactly the same height as the others. This seems to me to 

 be a simple case of an illusion of increased size produced by 

 a suggestion of increased distance when all the time there is 

 equality in size as in the case of the moon on the horizon 



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