PATTERNS CONSPICUOUS IN NATURE. 



393 



4. Relative Size of the Components. — For any given pattern 

 there is a particular proportion of the components which gives 

 the greatest blending distance. 



Text-fioure 6. 



T 



6'>^ni, 



3c)n 





A specimen of tlie patterns used in Experiment No. 7. 



Experiment No. 7. 



Candles 1 ft. 6 ins. apart. Objects 2 ft. 2 ins, from candles.] 



H:ick2:round grey. Objects square, 9 sq. cm. in size, divided horizontally into five 

 black and white stripes of 6 mm. (see te\t-fig. 6). 



Pattern blends at 

 In No. 1 there is 2 '8 Idack and 6 8 white 

 „ 2 „ 3/8 „ 5/8 

 „ 3 „ 4/8 ,, 4'8 

 „ 4 „ 5'8 „ 3/8 



,. 5 -,, 6/8 „ 2/8 



A striped pattern is dealt with in the above snmmarj'; it shows 

 that where the amount of black to white, or white to black, is 

 very small, the blending distance is smaller than when there are 

 about equal amounts of the two components. 



Referring also to experiment no. 9 (p. 397), it can be seen that 

 for the types of patterns here dealt with there is similarly a 

 parJiicular proportion of black to white which gives the greatest 

 blending distance luider the experimental conditions. 



5. Shape of the Components. — It has been shown that the 

 visibility of plain objects depends upon the concentrations of 

 their areas. Experiments show that, similarly, the blending 

 distance of patterns is proportional to the concentration of the 

 components of the patterns : the more concentrated the com- 

 ponents, the greater is the blending distance, as is seen in the 

 following experiment. 



EXPEEIMENT No. 8. 



The blending distance of black and white patterns, of which the components are of 

 the same size but of different shape. Experimental conditions : Candles 11 ins. 

 apart, and 2 ft. from glass plate on which patterns were fixed. 



Background behind glass plate, of grey paper, at such a distance that it is of the 



