3i6 
PHYSICS: A. G. WEBSTER 
Proc. N. a. S. 
EXPERIMENTS ON THE VIBRATION OF AIR IN CONICAL 
HORNS 
By Arthur Gordon Webster 
Clark University, Worcester, Mass. 
Communicated March 30, 1920 
At the meeting of the Committee on Sound of the National Research 
Council recently held at Geneva, Illinois, it was represented to me that 
my habit of not publishing results had been a- serious detriment to the 
progress of certain investigators in sound and I was strenuously urged to 
reform my habits. I shall, therefore, take the liberty of bringing out of 
my drawers a certain number of papers some of which I have had for many 
years but which for one reason or another have not been published. 
The curves presented herewith were shown at a meeting of the Amer- 
ican Association for the Advancement of Science in Columbus in 1915, 
but I believe have not been pubhshed. They were made by means of the 
phonometer and phone described in my paper in these Proceedings. 
5, May, 1919 (163-166), and they are intended to verify the theory of 
horns given by me in these Proceedings, 5, July, 1919 (275-283). 
The horn is always a portion of a circular cone mounted on one end of 
a cylindrical tube, the other end of which is closed. The sound was made 
by the phone emitting a constant sound of a pitch of 256 per second. 
The standing waves inside the horn were explored by an antenna con- 
sisting of a glass tube of three millimeters internal diameter and several 
feet long attached to a disk closing the end of a cylindrical tube screwed 
into the opening of the phonometer. This could be put into any part of 
