FALSE PARALLELS. 



marked it is almost impossible for the be- 

 holder to doubt that his eyes see cloud-lines 

 which are actually nearer together at their 

 extremities than they are in the middle of the 

 sky. 



This is one of Nature's deceptions. The 

 cloud-lines are really parallel ; they do not 

 converge at all. 



If we look along any long lines which are 

 parallel to each other, they appear to converge 



A B 



FlG. 53. A LAW OF PERSPECTIVE. 



together towards the end which is farthest from 

 us. Thus if we look along the inside of a 

 tunnel towards the entrance, as in Fig. 53, A, 

 or the railway lines in Plate VI., we see the 

 rails and the other lines of the tunnel, which 

 we know to be really parallel, appearing almost 

 to run into each other at a distance. Or, if 

 we look along a straight piece of path, bounded 

 by an iron fence and a wall, as in Fig. 53, B, 

 we notice the same thing. This is a well- 

 known effect of the conditions of vision, which 

 is called one of the laws of perspective. 



239 



