﻿

  from 
  an 
  Electrified 
  Point. 
  51 
  

  

  parallel 
  with 
  the 
  spark-gap, 
  served 
  to 
  indicate 
  the 
  potential- 
  

   difference 
  o£ 
  the 
  terminals. 
  

  

  P 
  , 
  Fig- 
  2. 
  

   P 
  

  

  ^ 
  

  

  fl 
  

  

  <S^n 
  

  

  .1 
  

  

  rdh 
  

  

  STORAGE: 
  CELLS 
  II— 
  1 
  

  

  Dry 
  dnst-£ree 
  air 
  was 
  the 
  only 
  dielectric 
  nsed. 
  Measure- 
  

   ments 
  were 
  made 
  at 
  three 
  pressures 
  for 
  point 
  positive. 
  

   Similar 
  measurements 
  for 
  negative 
  points 
  were 
  made 
  at 
  the 
  

   same 
  pressures. 
  Very 
  favourable 
  temperature 
  conditions 
  

   prevailed 
  during 
  the 
  entire 
  progress 
  of 
  the 
  work. 
  The 
  usual 
  

   temperature 
  was 
  21° 
  C. 
  No 
  variations 
  exceeding 
  1'5° 
  above 
  

   or 
  below 
  this 
  temperature 
  were 
  noted. 
  

  

  Tables 
  I. 
  to 
  VI. 
  inclusive 
  give 
  the 
  results 
  obtained. 
  These 
  

   are 
  represented 
  graphically 
  in 
  PI. 
  I. 
  figs. 
  1, 
  2, 
  and 
  3. 
  

  

  Table 
  I. 
  — 
  Air 
  75 
  cm. 
  Pressure. 
  

   Point 
  + 
  . 
  

  

  Distances 
  

  

  Least 
  P.D. 
  

  

  Distances 
  

  

  Least 
  P.D. 
  

  

  m 
  

  

  required 
  

  

  in 
  

  

  required 
  

  

  wave-lengths 
  

  

  for 
  discbarge. 
  

  

  ware-lengths 
  

  

  for 
  discharge. 
  

  

  Na 
  light, 
  

  

  Yolts. 
  

  

  Na 
  light. 
  

  

  Yolts. 
  

  

  1 
  

  

  282 
  

  

  10 
  

  

  517 
  

  

  1 
  

  

  292 
  

  

  12-5 
  

  

  517 
  

  

  1 
  

  

  329 
  

  

  14 
  

  

  517 
  

  

  o 
  

  

  354 
  

  

  15 
  

  

  526 
  

  

  2-5 
  

  

  432 
  

  

  20 
  

  

  545 
  

  

  3 
  

  

  361 
  

  

  20 
  

  

  587 
  

  

  o 
  

  

  366 
  

  

  20 
  

  

  598 
  

  

  4 
  

  

  354 
  

  

  20 
  

  

  526 
  

  

  4 
  

  

  488 
  

  

  25 
  

  

  531 
  

  

  5 
  

  

  517 
  

  

  25 
  

  

  532 
  

  

  5 
  

  

  499 
  

  

  30 
  

  

  599 
  

  

  5 
  

  

  470 
  

  

  35 
  

  

  583 
  

  

  7 
  

  

  499 
  

  

  35 
  

  

  610 
  

  

  7 
  

  

  526 
  

  

  40 
  

  

  604 
  

  

  7-5 
  

  

  526 
  

  

  45 
  

  

  637 
  

  

  8 
  

  

  540 
  

  

  50 
  

  

  658 
  

  

  10 
  

  

  516 
  

  

  50 
  

  

  640 
  

  

  10 
  

  

  517 
  

  

  50 
  

  

  650 
  

  

  E 
  2 
  

  

  