J 



PLATE 14. 



Fig. 105. The progress of a series of undulations admitted through an aperture. 



Fig. 106. Tiie difference of the paths of the light reflected from two points situated near 

 each other. 



Fig. 107. The difference of the paths of tlie light reflected from the opposite surfaces of a 

 thin plate. 



Fig. 108. The paths of two portions of hght supposed to pass through an inflecting atmo- 

 sphere. 



