﻿Deposited 
  by 
  Cathode 
  Discharge. 
  

  

  409 
  

  

  measurements 
  either 
  made 
  at 
  the 
  same 
  temperature, 
  or 
  reduced 
  

   to 
  the 
  same 
  temperature; 
  the 
  temperature-coefficients 
  of 
  the 
  

   several 
  tilms 
  having 
  been 
  carefully 
  determined. 
  

  

  These 
  records 
  are 
  exhibited 
  in 
  three 
  classes. 
  In 
  class 
  C, 
  

   where 
  the 
  films 
  were 
  imperfectly 
  aged, 
  the 
  variations 
  during 
  

   the 
  first 
  month 
  amounted 
  to 
  several 
  per 
  cent, 
  and 
  even 
  during 
  

   the 
  third 
  month 
  were 
  as 
  much 
  as 
  two- 
  or 
  three-tenths 
  of 
  one 
  

  

  Numbers 
  

  

  !. 
  

  

  Resistances 
  in 
  ohms. 
  

  

  

  Class 
  

   A. 
  

  

  1. 
  

  

  2265'S 
  

  

  2265-7 
  

  

  2265-8 
  

  

  2265-8 
  

  

  2. 
  

  

  37586- 
  . 
  

  

  37585- 
  

  

  37588- 
  

  

  37586' 
  

  

  r 
  

  

  3. 
  

  

  384*90 
  

  

  383-72 
  

  

  383-16 
  

  

  382-92 
  

  

  ri 
  | 
  

  

  4. 
  

  

  9999-5 
  

  

  9992-5 
  

  

  9990-3 
  

  

  9989-4 
  

  

  I 
  \ 
  

  

  5. 
  

  

  15722- 
  

  

  15697- 
  

  

  15685- 
  

  

  15681' 
  

  

  5| 
  

  

  6. 
  

  

  23335- 
  

  

  23680- 
  

  

  23765* 
  

  

  23774- 
  

  

  I 
  

  

  7. 
  

  

  165200- 
  

  

  167680- 
  

  

  167880- 
  

  

  167930- 
  

  

  d 
  ( 
  

  

  8. 
  

  

  84167- 
  

  

  83710- 
  

  

  83431- 
  

  

  83178- 
  

  

  3 
  1 
  

  

  9. 
  

  

  656030* 
  

  

  653600- 
  

  

  651620- 
  

  

  650110- 
  

  

  5 
  

  

  10. 
  

  

  4690000- 
  

  

  5008000- 
  

  

  5070000- 
  

  

  5080000 
  

  

  per 
  cent. 
  In 
  class 
  B, 
  more 
  perfectly 
  aged, 
  the 
  variations 
  dur- 
  

   ing 
  the 
  third 
  month 
  were 
  only 
  a 
  few 
  hundredths 
  of 
  one 
  per 
  

   cent 
  ; 
  while 
  in 
  class 
  A, 
  if 
  the 
  resistances 
  changed 
  at 
  all 
  during 
  

   the 
  three 
  months, 
  the 
  changes 
  were 
  so 
  small 
  as 
  to 
  be 
  within 
  

   the 
  range 
  of 
  errors 
  of 
  observation. 
  

  

  Physical 
  Laboratory 
  of 
  Columbia 
  University, 
  

   April 
  18, 
  1900. 
  

  

  