THE WAVE THEORY OF LIGHT. 



[A Lecture delivered at the Academy of Music, Philadelphia, 

 under the auspices of the Franklin Institute, September 

 29/7*, 1884.] 



THE subject upon which I am to speak to you this 

 evening is happily for me not new in Philadelphia. 

 The beautiful lectures on light which were given 

 several years ago by President Morton, of the 

 Stevens' Institute, and the succession of lectures 

 on the same subject so admirably illustrated by 

 Professor Tyndall, which many now present have 

 heard, have fully prepared you for anything I can 

 tell you this evening in respect to the wave theory 

 of light. 



It is indeed my humble part to bring before 

 you only some mathematical and dynamical de- 

 tails of this great theory. I cannot have the 



