721 



Number of seconds wanted for every 10 mm. displacement: 



from scale-division 750 — 700 from scale-division 700 — 650 



41 40 



50 42 



45 57 



48 49 



45 52 



sum total 3 min. 49 seconds, sum total 4 minutes. 



repeated once more : 



750—700 700—650 



38 44 



40 53 



48 43 



44 46 

 4J 53 



sum total 3 min. 31 seconds, sum total 3 min. 59 seconds. 



b. Determination of the ionisation with the emanation N°. 1 in 

 the apparatus after equilibrium has set in between this and its 

 radio-active products. 



1. time, wanted for the displacement from 750 — 700:2 m. 2 sec. 



„ „ „ „ 700-650:2 , 7 „ 



„ „ „ „ 650-600: 2 „ 25 „ 



sum total 6 m. 34 sec. 



2. when this is repeated once more we obtain: 



a displacement from 750 — 700 : 2 m. 2 sec. 

 „ 700—650:2 „ 22 „ 

 „ 650-60 0:2 „ 54 „ 



sum total 7 m. 34 sec. 



The mean of 1 and 2 is 6 ,, 56 ,, 



From a and 6 will now follow the correction of the natural leak : 

 This ionisation together with that of the emanation amounted to 

 6 min. 56 seconds, measured from scale-division 750 — 600; it can 

 then be derived from a, that the first mentioned ionisation alone 

 displaces the scale in 6 min. 56 sec. or 416 seconds from 750 — ^658. 

 Consequently this result has the same effect as if first only the 

 natural leak acts and that in 6 min. 56 seconds a displacement 

 from scale-division 750 — 658 and then the emanation alone from 

 658—600. 



For further conclusions we then want to know the ionisation, 

 onlv caused bv the emanation of the normal solution and this also 



