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this size the mind is perfectly acquainted; 

 but trees, bushes, hills, or pools of water, 

 are so various in their dimensions, that 

 we are never able to judge exactly of 

 their size, or at what distance they appear 

 to us. 



The second kind o? perspective is aerial, Aerial. 

 as it depends on the atmosphere; since 

 •we observe that objects not only diminish 

 in their size, but in their distinctness, in 

 proportion to the body of air betwixt the 

 eye and the objects : those nearest are 

 strongly represented, while other parts, 

 as they recede, become less distinct, till 

 at last the outline of a distant hill seems 

 melted into the air itself. Such are the 

 \d.ws of aerial perspective on all objects, but 

 not on all alike; since it is the peculiar 

 property of liglit, and the reflection of 

 light unmixed by colour, to suffer much 

 less by comparison than any other object. 

 It is for this reason that we are so much 

 deceived in the distance of perfectly zvhite 

 objects: the light reflected from a white- 

 washed house makes it appear out of its 

 place; snow, at many miles distance, ap- 



