I riple Pendulums with Mutual Interaction, oil 



10. Experiments on the disappearance of carbon monoxido 

 in the glow discharge are described. 



11. The results are discussed and explained by supposing 

 that the glow causes a chemical change in the gas, which is 

 reversible. The recognition of this reversibility seems 

 necessary to explain the phenomena. The disappearance of 

 other gases, illustrating other types of action, will be discussed 

 in the sequel. 



Research Laboratories of the General Electric Co., Ltd., 

 Hammersmith. 



April 16, 1920. 



LXX. Triple Pendulums loith Mutual Interaction and the 

 Analogous Electrical Circuits. — I. By Prof. E. H. Barton, 

 F.R.S., and H. M. Browning, M.S'c* 



[Plates XI.-XIJL] 



I. Introduction. 



MECHANICAL analogies to two circuits coupled together 

 have been used to show the type of vibrations set up 

 by the latter. (See " Coupled Vibrations," Phil. Mag. Oct 

 .1917, Jan. 1918 and July 1918.) 



The mathematical theory of these circuits is comparatively 

 simple, but the visual results of the mechanical analogy tend 

 to elucidate and interpret the theory. 



In the case of three circuits or three pendulums which are 

 arranged to act on one another, the theory is more com- 

 plicated, although in certain cases it can be resolved into a 

 somewhat simpler form. 



The experiments were carried out with a modified form of 

 the apparatus shown in figs. 1 and 2 of u Vibrations under 

 Variable Couplings " (Phil. Mag. Oct, 1917), and fig. 13, 

 Plate V. "Coupled Vibrations" (Phil. Mag. July 1918). 

 An extra bridle and pendulum were added, and three con- 

 nectors substituted for the single one, each of the three 

 connecting two of the pendulums. Later it was thought 

 that two connectors were sufficient, and the apparatus was 

 modified to obtain a result which might be more amenable to 

 analytical treatment. 



From the mathematical theory of three circuits coupled 

 each to the other two, it was expected that the mechanical 

 arrangement would give for each pendulum three superposed 

 * Communicated by the Authors. 



