Mr Richardson, On an atte?npt to detect radiation, etc. 177 



Pressure 



Initial 

 Readings of 

 Electroscope 



Final 

 Readings 



Leak in 

 Scale 

 Divi- 

 sions 



Duration 

 of Experi- 

 ment 



Leak 

 per hour 





mm. 



1-81 



Left Right 

 30-2—37-2 



Left Right 

 30-2—36-4 



0-8 



44 mins. 



1-0 Div. 



Wire not 

 excited 



1-81 



30-2—36-4 



30-2—36-0 



0-4 



36 „ 



0-7 „ 



Current 



passing 



tb rough 



wire 



•36— -28 



30 0—38-0 



29-8—36-0 



1-8 



3 hrs. 



0-6 „ 



No current 



through 



wire 



•28— -37 



31-0—39-2 



31-0—37-2 



2-0 



3 „ 



0-7 „ 



Current 



through 



wire 



The above experiments had been made with the cylinder 

 charged positively; they were now repeated with a negative charge 

 but no leak was obtained. The small Leyden jars (of about 

 400 cms. capacity) were next replaced by a paraffin condenser 

 whose capacity was about half a centimetre, and the pressure was 

 varied down to 0'01 mm. With these alterations several observa- 

 tions were taken, of which the following are examples. 



1. Aluminium wire, -6 mm. thick. 



Time of 

 Experi- 

 ment 



Pressure 



Diverg( 

 lea 

 Initial 



;nce of 

 ves 

 Final 



Leak 



Rate 



of 

 Leak 





mins. 

 50 



mm. 



•5— -08 



13-4 



12-4 



Divns. 

 1-4 



per hr. 

 1-5 



No discharge through 

 wire 



50 



•08— -3 



12-4 



11-4 



1-0 



1-1 



Curi-ent through wire 



2. Steel 



wire, •' 



39 mm. 



thick a 



! very I 



ow pressures. 



100 



•01— -02 



41-5 



40-2 



1-3 



0-8 



No current through 

 wire 



106 



•03— -07 



43-2 ; 42-2 



| 



1-0 



0-65 



Current through wire 



