72 Bronson — Transverse Vibrations of Helical Springs. 



3. The approximate constancy in pitch for a considerable 

 change in length, which has been so often noticed with india- 

 rubber cords, is also observed in a still more marked degree in 

 the case of helical springs. 



-i. This approximate constancy of pitch for a considerable 

 change in the length of both the rubber cords and the springs 

 is due to the fact that during the change, the length and ten- 

 sion have remained nearly proportional. 



In conclusion I desire to express my thanks to Professor 

 A. W. Wright for suggesting the subject and furnishing the 

 apparatus and assistance necessary in carrying on the inves- 

 tigation. I wish also to thank Mr. O. C. Lester for his assis- 

 tance in performing the experimental work. 



Sloane Physical Laboratory, 

 Yale University, May 1, 1904. 



