RAINBOW. 395 



The ray SB is divided into the three colours; the 

 blue is bent above the eye, and the red falls lelow the 

 eye D ; but the yellow enters it. 



The ray S C is also divided into the three colours. 

 The blue (which is bent most) enters the eye; 

 and the other two fall below it Thus the eye sees 

 the blue of C, and all drops in the position of C ; 

 the yellow of B, and of all drops in the position of 

 B; and the red of A, &c. ; and thus it sees a 

 rainbow. 



Q. Does EVERY person see the SAME colours 

 from the SAME DROPS ? 



A. No ; no two persons see the same 

 rainbow. 



To another spectator the rays from S B might be red 

 instead of yellow; the ray from S C, yellow ; and the blue 

 might be reflected from some drop below C. To a third 

 person the red may issue from a drop above A, and 

 then A would reflect the yellow, and B the blue, and 

 so on. 



Q. Why are there often TWO EAINBOWS at one 

 and the same time ? 



A. In one rainbow we see the rays of 

 the sun entering the rain-drops at the 

 top, and reflected to the eye from the 

 bottom. 



In the other rainbow, we see the rays 

 of the sun entering the rain-drops at the 

 bottom, and reflected to the top, whence 

 they reach the eye. 



