676 ALEXANDER MACFARLANE AND R. J. S. SIMPSON ON THE 
Relative Difference of Potential required to produce a Single Spark. 
Dielectric, Oil of Turpentine. Electrodes, Disc and Plate. Pressure, 625 mm. — 

Ss. Vv. < 
Distance between : Mean difference 
Dike ancl Eines [2 EES ae manic | 
, 
n. n'. i= 10 

‘1 centimetres, { ee ae = } 35°5 
465 494 29 
o if { 438 497 59 ee 
448 500 52 
Es : 335 490 155 ore 
390 490 100 
a t { 310 495 185 tele 
315 498 183 
* ‘ { 280 500 220 \ ae 
325 502 | 177 
. ; ( 200 505 =| 305 Lt psy 
250 505 255 J 
in : { 165 510 345 Vel eens 
\ 175 515 340 J 


We conclude that a straight line passing through the origin represents 
approximately the.dependence of V upon S. , 
We have also obtained observations for a continued discharge. They are 
very regular in themselves, but their interpretation or correction is difficult. 
They indicate a straight line not passing through the origin, of much smaller in- 
clination to the axis of S than the straight line for the single discharge. 
Relative Difference of Potential required to produce a Continued Discharge.— 
Conditions same as above. 

8 
Distance peace d : 
DiseandPings Deflection. Zero. Difference, 
N. nN. nN —N. 


1 centimetres, 465 510 45 
“2 B 470 535 65 
3) a 470 565 95 
“4 3 470 588 118 
75) 470 610 140 
6 as 465 625 160 i 
7 , 





