Discharges in Electrodeless Vacuum- Tubes. 



509 



single broad band-ring is obtained, as the two turns will help 

 one another with respect to magnetizing effect. 



Doing the same with the wire (fig. 5) a discharge is 

 obtained shaped like the sector of an orange, as shown by the 

 dotted lines, fig. 7. 



Expt. 8. — Bending a wire as shown in fig. 8, and placing a 

 bulb in the loop b c, there is no effect even with a long spark- 

 gap, although the potential difference between the sides 



Fiff. 8. 



c and b would be much greater than in the case of a single 

 turn. 



Putting a bulb in the loop, b c, of fig. 4 at once gives a 

 bright ring. 



