592 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Then for f x = a and g 1 = a 
F* = 
01 + 02 
and for f 2 =cx and g 2 = cc 
V ^ and G 2 = , 
_r0j_ 
01 + 02 
Tfl _ ^ 01 p 
A 1 - ~T , J — — f T 2 
01 ~T~ 02 
G, 
r $ 
- = - F y . 
01 + 02 
Finally, eliminating r by means of 
r = G, + G 2 = - (F, + F 2 ), 
we have 
A A 
£7i 
As regards the size of the image, we have from fig. 70, 
Fig. 70. 
^ap = J7i 
ft »• * ar £72 ’ 
and from the above equations 
ft = i = Gi 
ft G 2 .<7 2 — G 2 
ft = *Wi F 2 
ft F x F 2 — / 2 
The formation of the image in the Lampyris-eje may be looked at in 
