THE ZODIACAL LIGHT. 



357 



In this diagram, the sun's rays being S', S", etc., BO, FO, etc. 

 will be the reflected rays ; and the several angles between these lines 

 of incidence and reflection, together with the number of rays reflected 



^"-^^IW^. 





NEBtTLOus Ring, with the Earth fob its Centre. 

 [The relative proportions of tiie earth and the ring, and also its distance, are of course not given 

 in this diagram with any etibrt at certainty ; the upward extent of the ring is probably far 

 greater than can be here represented. The diagram is, however, sufficiently correct for our 

 present purposes of elucidation.] 



to the eye, out of every 1,000 incident rays, according to Bouguer, are 

 in the followins; table : 



ANGLE. 



S', BO 161. 



S", FO 146. 



S"',DO 131. 



S"",HO 116. 



S'"", at midnight... 90. 



S""',CO 67. 



Rays reflected from 

 Smooth Water. 



Rays reflected from 

 Plate-glass not quick- 



