348 



"WELLS'S NATURAL PHILOSOPHY. 



Sucli a modiflcatiou of the camera is very convenient for artists and travelers 

 ia sk etching landscapes, etc. 



Fig. 281, 



now does the '''08. The mechanical arrangement of the 

 thi "camera ^7® ^^ viau. and thc higher animals is the same 

 obscura? j^g ^j^g^^ ^f j-\^q camera obscura, being simply a 



double-convex lens, fitted into one side of a spherical 

 chamber, through which the rays of light pass to form an 

 inverted picture upon the back of the chamber.* 

 What is the ^^ man, the organs of vision consist of two 

 urro7th'e"eye liollow sphcrcs, cach about an inch in diam- 

 in man? eter, filled with certain transparent liquids, and 



deposited in cavities of suitable magnitude and form, in 

 the upper part of the front of the head on cach side of 

 the nose. 



The sphere of the eye, or the eye-ball, is 

 moved in its socket by muscles attached to 

 different points of its surface, so that it is 

 capable of being moved within certain limits 

 in every direction. 



• This may be proved by taking the eye of a recently-killed buUock and cutting* Email 

 iole in the upper part of the ball, looking into the interior. 



How are we 

 enabled to 



move the eye 

 in different di- 

 rections ? 



