Proceedings of the American Academy of Arts and Sciences. 

 Vol. XL. No. IG. — FEiiuuAUY, 1905. 



THE ACHROMATIZATION OF APPROXIMATELY MONO- 

 CHROMATIC INTERFERENCE FRINGES BY A HIGHLJ 

 DISPERSIVE MEDIUM, AND THE CONSEQUENT IN- 

 CREASE IN THE ALLOWABLE PATH-DIFFERENCE. 



By R. W. Wood. 



Investigations on Light and Ebat made or published, wholly or in pari, with Appeopriations 

 from the rumford fund. 



