PERSPECTIVE. 379 



always adiiered to ; for when we stand upon high 

 ground, the horizontal hne rises in proportion. 

 Suppose the view to be taken on level ground, the 

 head of a man represented standing on the ground, 

 would come to this line, and that whether the 

 man be near or far off; that is, wherever his feet 

 are, his head must always come to the horizontal 

 line, if he be standing upright on the ground. 



Distance of the picture means the supposed dis- 

 tance of the eye from the centre of the perspective 

 plane or picture. 



This distance may be chosen at pleasure ; but 

 a judicious choice of it is very important, for the 

 variation of this distance affects every perspective 

 representation, so as to render them either pleasing 

 or distorted. Long distances, in general, give the 

 best representation ; but they are not always con- 

 venient, or to be attained. Experience alone can 

 direct a proper medium. 



Parallel pei^spective is where the picture is sup- 

 posed to be so situated, as to be parallel to the 

 side of the principal object in the picture, as a 

 building, for instance. Then the lines on those 

 sides of the building that are parallel to each other 

 continue parallel on the picture, and do not vanish 

 into any point ; while the lines at right angles to 

 the former vanish into the centre of the picture. 

 This will be exemplified in Plate 6. Fig. 1. 



The picture being supposed to stand parallel to 

 the side of the house A B C D, the lines A B, DC, 

 which in Nature are parallel to each other, must 

 be made parallel in the perspective representation. 

 But the lines BE, CF, which in Nature are at 

 right angles to A B, and D C, and, consequently, 

 also to the picture, tend towards a point ; and this 



