Chap. 5.] Beautiful and deformed Images. 025 



part of the reflecting furface intercepted between th:fe 

 fines is that part which reflects the rays to the c^e. 

 Let O be the eye of the fpectator, Fig. 8, 9, loin O q y 

 O r> and produce themj if neceilary, till they cut the 

 reflecting furface in m and #, iiien m n is the pa^t of 

 the reflecting fur : ::u.e :n which the image is feen } and 

 the rays Qj;;> R n, refined in the direction m O, n O, 

 are thofe by which the extreme parts of the object are 

 leen. 



This would be ftrictly true in all cafes, if rays pro- 

 seeding from an object made ^it always vifible and 

 clear -, but we are accuilomed from our infancy to de- 

 termine on the nature and pofition of objects by rays 

 'diverging from them. To fee, therefore, by reflected 

 rays, they mud appear to the eye to diverge from 

 the image, which will not be the cafe when the eye 

 is at a lefs diftance from a concave reflector than the 

 image. In that cafe our vifion is confufed, the image 

 is behind us, and we can form ito conception of it. 

 But this will be farther explained when I come to 

 treat on the nature of vifion. 



Upon the principles now laid down, we fee the rea- 

 Jbn of thofe beautiful and deformed images made by 

 'objects placed before fpherical reflectors, as alfo the 

 changes produced in tfcem by their various pofitions 

 with refpect to the reflector. When a perfon is at a 

 greater diilance from a concave fphefical refle6tor than 

 the radius, he perceives an image, for in{tance> of him- 

 felfj much diminiihed, itanding upon its head before 

 the reflecting furface in the air ; as he walks towards 

 the center^ the image walks towards him, increafing in 

 magnitude j as he walks from the center to the prin- 

 cipal focus, his image appears confufed, and he cannot 

 afcertain any of its parts -, as he walks from the prin- 

 cipal focus, to the furface, the image is again clearly 

 VOL. I; Q vifible, 



