652 



BELL SYSTEM TECHNICAL JOURNAL 



11 = 



n = 1 



n = 2 



11 = 3 



n = 4 



Fig. 3— Graphs for the family of pairs p" e\p{-ira-p) a »D„" exp(-■!rgVa')• 

 The heavy curves show the cases a = 1, 7? = 0, 1, 2, 3, 4; the dotted curves on the 

 left are for the same values of n but for the limit a — O. On the right the curves 

 apply for any value of a if the horizontal and vertical scales are multiplied by a and 

 o~"~' respectively. 



