Rainbow due to a Circular Source of Light. 609 
Fig, 1.—Intensity Curve. 
Dotted curve represents Airy’s value of /”. 
une (1) > F, for circular source 26=32', \.=5893 x 10-8 em., 7=0°025 cm. 
fee CO, . Daicer : 7=0-05 em. 
Fig. 2.—Intensity Curves for Primary Colours (Point Source.) 
_»_: *_. eurye (C) ic. 4 as 1-60/2( 
== — eurve (1) Pes total intensity. 
¢ 
