584 HENRY A. ROWLAND 



does. But he was not quite up to his usual pitch when he made that 

 statement, because if he had thought a moment he would have seen that 

 very short waves will go more nearly in a straight line than long ones. 

 But any single impulse, such as Stokes suggests, would go into the 

 shadow. The only wave motion that would go in a straight line is a 

 series of waves, one after another. Therefore, these rays cannot he 

 single impulses coming irregularly. 



Prof. Michelson has suggested a theory of rays based on something 

 like vortex rings in the ether. Now, if we have an ether that can carry 

 on light waves and electromagnetic waves, it cannot be a perfect fluid; 

 it has got to be something else. You cannot very well imagine vortex 

 rings in such an ether. So that we are met at every point by some 

 objection. We have been studying light for hundreds of years; we are 

 not anywhere near satisfied with the theory yet, and we cannot very 

 well be expected to be satisfied with the theory of Rontgen rays in one 

 year. 



Well, I think that is all I can say with regard to the subject, and I 

 hope the other gentlemen who are to carry on the discussion will satisfy 

 you on all these points that I have brought up and left unanswered. 



[There followed a discussion by Professor Elihu Thomson, Professor 

 M. I. Pupin, and others.] 



PROF. ROWLAND: I made a few notes with regard to what has been 

 said, but they are made in such a way that I do not believe that I can 

 interpret them myself, especially as the hour seems to be getting rather 

 late. One or two remarks, however, I would like to make. When 

 Prof. Thomson said that he got such a large amount of rays from an 

 insulated piece of platinum by letting the cathode rays fall upon it, 

 he made a sketch. With the exception of this end, which was flat, 

 that is the kind of thing that I used. Now, there was absolutely 

 no effect when this was made an anode and this a cathode, so that all 

 the cathode rays were striking on the platinum. I have the photo- 

 graph; I got no effect whatever. Now, if Prof. Thomson got an effect 

 in this case and I did not get an effect in that case, I have got a case, 

 at least, where none of these rays were produced by the falling of the 

 cathode rays upon the object. It doesn't make any difference how 

 many other persons have something in which they do get an effect. 

 If I did not get an affect, that is one case, understand. That is the 

 case where the cathode ray fell on an object and I got no Rontgen ray. 



