210 



On an Atomic Model. 



With a large number of balls the motion is very much more 

 complicated than one would expect. At times a ball will 

 start out from the outer ring and apparently seem to try to 

 escape from the system. In consequence of the friction of the 

 mercury and the nature of the field, the ball always returns. 

 If a ball were to escape it would cause a rearrangement of the 

 others, or a disturbance similar to that caused by an added 

 ball. This tendency of the ball to fly off is especially great 

 if the current through the mercury is increased, or if the 

 system absorbs energy. This may be an illustration of what 

 takes place in the photo-electric effect, or in the case of 

 ionization produced by hot bodies. 



In the case when a ball flies out when rotating at normal 

 or constant velocity, we have an explanation of 7 rays caused 

 by /? rays. Or we may let the balls represent a. rays, helium 

 atoms, or that which in the atom of radium makes a, rays or 

 helium atoms after they have escaped, and we have an 

 illustration of a radioactive substance. 



To illustrate the disintegration of an atom of radium 

 through its several disintegration products, I made a tray in 

 which I embedded a ring of iron, so as to make a magnetic 

 field which is strong at the centre and diminishes as we go 

 along any radius, passing through a minimum and then 



Fig. 2. 



AD< 



>0B 



1 — 







00 



N 



00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 





00 



00 



S 



00 



1 





— 1 



through a maximum over the ring of iron. Fig. 2 is a 

 cross-section of the tray and central magnet. N S is the 

 central magnet. R R is the cross-section of the iron ring. 

 A and B are binding posts by which the current is led in 



