476 Dr. J. Robinson on Kdnig's Theory of the 



force, whose magnitude and direction are in agreement with 

 that demanded by the electromagnetic theory of Maxwell. 



The first part of the work was done in the laboratories o£ 

 the University of Chicago, the second part at the University 

 of Texas. To the members of the Physics Faculty of the 

 University of Chicago I wish to express my thanks for the 

 appreciative interest they have continually shown in the 

 progress of my work. 



Austin, Texas, August 15, 1909. 



LI. On Konig's Theory of the Ripple Formation in Kundt's 

 Tube. By James Robinson, M.Sc, Ph.D., late Pemberton 

 Fellow of Armstrong College (University of Durham), 

 Newcastle-on-Tyne *. 



SOME time ago on the suggestion of Prof. Eduard Riecke, 

 I performed some experiments to test Konig's theory of 

 the ripple formation in Kundt's tube experiment. A calcu- 

 lation | was made to find how the distance between the ripples 

 varies along the tube, and some measurements were recorded 

 which showed a qualitative agreement with th3 result of this 

 calculation. In a communication to me from Prof. Konig he 

 quite agreed with the work of the previous papers, but 

 thought that a better agreement between theory and ex- 

 periment ought to be expected. As a result of this, the 

 present investigation was taken up. First of all another 

 method of deducing Konig's theory is given. An extension 

 of the theory is then given, and by means of this, a better 

 agreement between theory and experiment shown to exist. 



Konig's Theory. 



Kirchhoff J worked out the general equations for the 

 motion of two spheres in a fluid. He found these to be 



dt ~dui 'da 1 1 ' dt ~£u<l B<x 2 

 dfdvi ~dbi 1} dfbv 2 d& 2 2 ' 



dt "diVi dci ' dt ~^w 2 B c 2 2 " 



* Communicated bv Prof. H. Stroud. 



f Robinson, Phil. Mag. July, 1909. 



X Kirchhott, Mechanik, 18 & 19 Vorlesiingen, 



