﻿32 
  Dr. 
  A. 
  C. 
  Crehore 
  on 
  the 
  Formation 
  of 
  the 
  

  

  with 
  the 
  view. 
  As 
  the 
  distance 
  from 
  the 
  spheres 
  was 
  at 
  

   least 
  250 
  cm., 
  this 
  displacement 
  of 
  the 
  camera 
  by 
  2*5 
  cm. 
  

   to 
  one 
  side 
  of 
  the 
  vertical 
  line 
  caused 
  no 
  appreciable 
  

   distortion 
  due 
  to 
  perspective. 
  Tt 
  is 
  most 
  fascinating 
  

   and 
  instructive 
  to 
  watch 
  the 
  oscillations 
  of 
  the 
  spheres 
  

   as 
  they 
  are 
  assuming 
  their 
  final 
  positions. 
  A 
  moving 
  picture 
  

   film 
  recording 
  these 
  motions 
  might 
  be 
  instructive, 
  and 
  

   certainly 
  would 
  be 
  of 
  interest. 
  

  

  In 
  this 
  manner 
  the 
  set 
  of 
  negatives 
  of 
  each 
  combination 
  

   from 
  tw 
  r 
  o 
  to 
  eleven 
  spheres, 
  reproduced 
  in 
  fig. 
  3 
  i 
  v 
  Pl. 
  II.), 
  was 
  

   obtained. 
  The 
  plates 
  used 
  were 
  3^ 
  by 
  4^ 
  inches, 
  a 
  size 
  

   adapted 
  for 
  use 
  in 
  a 
  stereopticon. 
  When 
  measurements 
  are 
  

   desired, 
  the 
  figures 
  are 
  projected 
  by 
  the 
  lantern 
  upon 
  a 
  

   drawing-board 
  and 
  the 
  positions 
  marked 
  in 
  the 
  enlargement, 
  

   where 
  measurements 
  may 
  easily 
  be 
  made 
  with 
  some 
  degree 
  

   of 
  accuracy. 
  This 
  set 
  of 
  negatives 
  was 
  secured 
  during 
  the 
  

   first 
  three 
  days 
  of 
  May, 
  but 
  on 
  the 
  next 
  day 
  rain 
  and 
  wet 
  

   weather 
  set 
  in, 
  which 
  entirely 
  prevented 
  any 
  repetition 
  of 
  

   the 
  series 
  in 
  the 
  same 
  manner, 
  because 
  the 
  condenser 
  would 
  

   immediately 
  discharge 
  at 
  such 
  a 
  rate 
  that 
  there 
  was 
  not 
  time 
  

   for 
  the 
  oscillations 
  to 
  die 
  out, 
  and 
  for 
  the 
  figures 
  to 
  be 
  

   formed, 
  although 
  there 
  was 
  furnace-heat 
  in 
  the 
  room 
  for 
  the 
  

   purpose 
  of 
  keeping 
  the 
  apparatus 
  dry. 
  It 
  will 
  not 
  be 
  

   practicable 
  to 
  work 
  again 
  by 
  this 
  method 
  until 
  the 
  cold 
  dry 
  

   season. 
  The 
  method 
  is 
  very 
  satisfactory 
  because 
  there 
  is 
  no 
  

   disturbing 
  cause 
  for 
  variation 
  of 
  potential 
  which 
  is 
  always 
  

   present 
  when 
  the 
  source 
  of 
  power 
  is 
  connected. 
  On 
  account 
  

   of 
  the 
  weather 
  another 
  plan 
  was 
  adopted 
  and 
  good 
  negatives 
  

   secured, 
  as 
  described 
  below. 
  

  

  An 
  examination 
  of 
  the 
  figures 
  assumed 
  by 
  the 
  spheres 
  in 
  

   fig. 
  3 
  (PI. 
  IP) 
  shows 
  that 
  they 
  not 
  only 
  differ 
  from 
  those 
  in 
  the 
  

   calculated 
  table, 
  but 
  also 
  from 
  those 
  obtained 
  with 
  magnets. 
  

   With 
  magnets 
  the 
  central 
  rings 
  begin 
  to 
  form 
  earlier 
  for 
  

   a 
  smaller 
  number 
  of 
  magnets 
  than 
  the 
  calculated 
  figures, 
  

   and 
  they 
  form 
  earlier 
  still 
  in 
  fig. 
  3. 
  The 
  whole 
  series 
  may 
  

   be 
  said 
  to 
  be 
  farther 
  away 
  from 
  the 
  figures 
  in 
  Table 
  I. 
  than 
  

   those 
  obtained 
  with 
  magnets. 
  For 
  example, 
  the 
  third 
  ring 
  

   beoins 
  to 
  form 
  when 
  the 
  eleventh 
  sphere 
  is 
  added, 
  instead 
  of 
  

   at 
  the 
  seventeenth 
  electron 
  as 
  in 
  the 
  table. 
  

  

  With 
  an 
  arrangement 
  like 
  this 
  all 
  the 
  spheres, 
  being 
  

   connected 
  together, 
  are 
  at 
  the 
  same 
  electrical 
  potential, 
  

   and 
  the 
  charge 
  is 
  greater 
  on 
  the 
  spheres 
  in 
  the 
  outside 
  ring 
  

   than 
  upon 
  those 
  in 
  the 
  centre 
  of 
  the 
  system. 
  Hence, 
  the 
  

   desired 
  figures 
  ought 
  not 
  to 
  be 
  formed 
  without 
  further 
  

   modification. 
  

  

  Before 
  describing 
  any 
  modification 
  of 
  this 
  experiment, 
  it 
  

  

  