Ultra-Violet Light on Moist Air, 



307 



coil connected with the town mains (100 volts alternating). 

 Several large Leyden jars were in parallel with the spark gap. 



G = 'T . 



u 



Elevation 



o A 



A« 



Plan 



The light was brought to a focus in the middle of the cloud 

 chamber by the quartz lens L, which was adjustable in position. 

 The clouds were observed by means of a glass lens GL, which 



