PHYSIOLOGICAL PARADOXES. 



Lastly, a view from an opposite height often 

 brings into view higher portions of a hill which 

 had been invisible from the lower ground. 

 Recurring to Fig. 55, we see that if the hill 

 BCD had a higher summit F, this would be 

 invisible from B or G on the level ground, being 

 concealed behind the lower shoulder C, while 

 it would be brought into view by climbing up 

 the opposite hill to E. 



Thus there are several ways in which view- 

 ing a hill from an opposite hill makes it look 

 higher, while it is undoubtedly the case that 

 small hills looked down upon from a mountain- 

 top lose their apparent height and often cease 

 to be distinguishable from level ground. 



4. False Continuity. 



Our eyes see great differences in the surface 

 and texture of objects. A sponge, a heap of 

 grain, a heap of lump sugar, are all obviously 

 porous and discontinuous masses. Sandstone, 

 brick, and paper are less obviously of the same 

 structure, yet a little close observation shows 

 that these also consist of separate pieces with 

 spaces between, though the pieces and spaces 

 are both on a smaller scale. 



Many other substances appear to be of an 

 entirely diiferent construction. The surface 

 of the skin, the nail, a glass tumbler, or a copper 

 tube, the inside material of a piece of wax, or 



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