On the Sounds of Splashes. 145 



seem to be the two aspects of the motion of a single fluid 

 related by the equivalence equation 



The relations m cc five and e cc Kvm were indicatediin a paper 

 submitted by the present writer to the Science Convention, 

 Calcutta, 2nd March, 1 919. Dr. D. N. Mallik's opinion that 

 it would demonstrate that the electron was a vortex formed 

 a great incentive for trying the magnetic analogue of the 

 circular electric current. I am obliged to Messrs. N. V. 

 Joshi, B.Sc, and Ham Chandra Sinha of Canning College, 

 for aid in setting up the apparatus and taking observations. 



Luclmow, India, 

 7th June, 1919. 



X. On the Sounds of Splashes. 

 By Prof. C. V. .Raman, M.A., and Ashutosh Dey*. 



[Plate 1.] 



IN his interesting book on splashesf, the late Prof. 

 Worthington described the results of an extensive 

 series of photographic studies of the phenomena accom- 

 panying impact on a liquid surface. The successive stages 

 of the splash of a drop for various heights of fall, and the 

 splashes produced by solid spheres impinging on a liquid 

 surface, were all fully investigated and described. Prof. 

 Worthington showed that the splashes produced by solid 

 spheres are of two kinds, the "smooth " or " sheath " splash, 

 and the " rough" or " basket " splash ; whether the one or 

 the other kind of splash is produced depends on the condition 

 of the surface of the sphere, the height of fall, and the 

 nature of the liquid. The " smooth" splash is practically 

 noiseless, and the " rough " splash is noisy and violent. In 

 the latter case, it was observed by Prof. Worthington that 

 the sphere when entering the liquid drags the air down with it, 

 forming a cavity in its wake, and the successive changes in 

 the form of this cavity, its bifurcation, and the formation 

 of vertical jets of liquid within and above the cavity are 

 beautifully illustrated in his book by a series of: instantaneous 



* Communicated by the Authors. 



t ' A Study of Splashes,' Longmans, Green & Co., 1908. The book 

 contains (with some additions) the substance of two papers by 

 Worthington and Cole, Phil. Trans. Boy. Soc. 1897 and 1900. 



Phil. Mag. S. 6. Vol. 39. No. 229. Jan. 1920. L 



