1891.] 



the Discharge of Lei/den Jars. 



43. Summary of Experiments with Tube-condenser No. 2. 



(" Longer Leads.") 

 Equivalent length of A spark, 9'22 mm. (June, 1888). 



The two sets with 15 cm. of the condenser in use are on different 

 days, the only difference being that in (2) the discharge circuit was 

 turned round 180 so as no longer to be beneath the longer leads at a 

 possibly interfering distance. The absolute reading differs, but the 

 maximum occurs in the same place. 



The maxima in all this set are by no means well-marked, but there 

 is an indication of a second maximum in the last column, at about 

 u = 40 ; and of still another near the bottom. Taking the self- 

 induction of the discharge circuit as 19J X 45, and the capacity of 

 the jar as 450, the calculated wave-length for u = 40 comes out 

 38J metres, or just the first harmonic of the leads-vibration. 



The second harmonic occurs at u = 15; with wave length 26J 

 metres. There is a sign of another maximum near 150 ; and calcula- 

 tion places a fundamental vibration, agreeing in period with the 

 leads, at about u = 167. 



