380 



Mr. A. A. Campbell Swinton. 



the cathode stream, described recently by the writer in two papers to 

 the Physical Society.* 



For the purpose of testing this, several experiments were made. 

 Firstly, a tube was constructed in which the anticathode was mounted 

 on an axis, so that by rotating it through a small angle the cathode 

 rays could be reflected on to one side or the other of a very delicately 

 pivoted mill wheel with mica vanes. That the rays were so reflected 

 was apparent from the fluorescence of the glass and the shadows cast 

 by the vanes, but the rotations of the wheel were quite inconclusive, 

 and did not appear to have any definite relation to the direction of the 

 reflected cathode rays. 



The tube shown in fig. 3 was next constructed. In this tube there 

 is a diaphragm of mica, that divides the tube into two portions. 

 One portion contains the six-vaned mill wheel M, and the other the 



cathode C, and an inclined anticathode A. The diaphragm is pierced with 

 two oblong apertures, and the anticathode arranged on a sliding stem 

 so that it can be placed to reflect the cathode rays through one or other 

 aperture on to one side or the other of the wheel as desired. When ex- 

 hausted and connected either to an induction coil or influence machine, 

 the reflected cathode rays from A in either position passing through 

 the corresponding aperture in the diaphragm, gave a distinct patch of 



* Phil. Mag./ October, 18C8, pp. 387395. 



