﻿German-Silver 
  and 
  Platinoid 
  Wires. 
  159 
  

  

  packed 
  in 
  tin-lined 
  soldered 
  cases 
  containing 
  straw, 
  and 
  were 
  

   shipped 
  to 
  Vera 
  Cruz, 
  on 
  the 
  Mexican 
  Coast 
  — 
  a 
  voyage 
  of 
  

   twenty-six 
  days. 
  A 
  month 
  after 
  leaving 
  England 
  the 
  cases 
  

   were 
  unpacked. 
  It 
  was 
  then 
  noticed 
  that 
  the 
  leather 
  lappings 
  

   of 
  the 
  bobbins 
  had 
  deteriorated, 
  the 
  silk 
  coverings 
  were 
  dis- 
  

   coloured, 
  the 
  german-silver 
  had 
  become 
  brittle, 
  and 
  breaks 
  

   had 
  occurred 
  in 
  the 
  wire. 
  The 
  packing-straw 
  showed 
  signs 
  

   of 
  dampness. 
  The 
  case 
  had 
  been 
  stowed 
  in 
  the 
  hold 
  with 
  

   other 
  cargo 
  in 
  rather 
  a 
  hot 
  part 
  of 
  the 
  ship. 
  No 
  current 
  was 
  

   ever 
  sent 
  through 
  this 
  wire 
  except 
  the 
  small 
  fraction 
  of 
  a 
  

   milliampere 
  used 
  momentarily 
  while 
  testing 
  the 
  resistance 
  

   before 
  shipment. 
  

  

  (2) 
  In 
  February 
  1891 
  similar 
  bobbins, 
  of 
  nominally 
  the 
  

   same 
  german-silver 
  wire, 
  were 
  shipped 
  to 
  Valparaiso 
  and 
  

   Iquique. 
  These 
  were 
  not 
  treated 
  with 
  paraffin-wax, 
  they 
  

   were 
  merely 
  lapped 
  with 
  leather. 
  During 
  the 
  Chilian 
  war 
  

   the 
  apparatus 
  was 
  dismantled. 
  I 
  have 
  had 
  no 
  information 
  as 
  

   to 
  the 
  state 
  of 
  these 
  bobbins 
  since 
  January 
  1893, 
  when 
  the 
  

   wire 
  was 
  reported 
  to 
  be 
  in 
  good 
  condition. 
  The 
  mean 
  tem- 
  

   perature 
  of 
  Valparaiso 
  is 
  lower 
  by 
  about 
  10° 
  C. 
  than 
  the 
  mean 
  

   temperature 
  of 
  Vera 
  Cruz. 
  

  

  (3) 
  In 
  June 
  1895 
  bobbins 
  of 
  platinoid 
  were 
  shipped 
  to 
  the 
  

   town 
  of 
  Bahia, 
  on 
  the 
  Brazilian 
  coast. 
  The 
  wire 
  was 
  silk- 
  

   covered 
  and 
  treated 
  with 
  paraffin-wax. 
  No 
  leather 
  or 
  ebonite 
  

   was 
  used 
  in 
  connexion 
  with 
  this 
  apparatus. 
  An 
  outer 
  box 
  of 
  

   mahogany 
  protected 
  the 
  bobbins 
  from 
  insects. 
  At 
  the 
  end 
  of 
  

   a 
  very 
  wet 
  and 
  stormy 
  season 
  the 
  wire 
  failed. 
  It 
  was 
  reported 
  

   " 
  faulty 
  " 
  in 
  January 
  1896, 
  about 
  six 
  months 
  after 
  its 
  arrival 
  

   in 
  Brazil. 
  When 
  unwound, 
  the 
  wire 
  showed 
  several 
  fractures; 
  

   it 
  had 
  become 
  "short" 
  locally. 
  Bahia 
  lies 
  almost 
  on 
  the 
  

   same 
  isotherm 
  as 
  Vera 
  Cruz, 
  25° 
  C. 
  

  

  (4) 
  Between 
  the 
  months 
  of 
  June 
  and 
  August 
  1893 
  bobbins 
  

   of 
  platinoid 
  were 
  shipped 
  to 
  Valparaiso, 
  Iquique, 
  and 
  Chorillos. 
  

   The 
  wire 
  was 
  silk-covered 
  and 
  treated 
  with 
  paraffin-wax. 
  

   Each 
  bobbin 
  had 
  an 
  outer 
  tube 
  of 
  ebonite. 
  There 
  have 
  been 
  

   no 
  reports 
  of 
  failure 
  from 
  any 
  of 
  these 
  towns. 
  This 
  goes 
  to 
  

   prove 
  that 
  the 
  presence 
  of 
  ebonite 
  is 
  not 
  itself 
  sufficient 
  to 
  

   account 
  for 
  the 
  fracture 
  of 
  platinoid 
  wires. 
  

  

  (5) 
  In 
  November 
  1893 
  similar 
  bobbins 
  were 
  shipped 
  to 
  

   Galveston 
  and 
  Coatzacoalcos 
  : 
  no 
  faults 
  have, 
  so 
  far, 
  developed 
  

   in 
  them. 
  Here, 
  again, 
  ebonite 
  has 
  done 
  no 
  evident 
  harm. 
  

   Coatzacoalcos 
  is 
  nearer 
  to 
  the 
  equator 
  than 
  is 
  Vera 
  Cruz. 
  

  

  (6) 
  In 
  December 
  1894 
  similar 
  bobbins 
  were 
  shipped 
  to 
  

   Santa 
  Elena, 
  on 
  the 
  coast 
  of 
  Ecuador, 
  and 
  to 
  San 
  Juan 
  del 
  Sur, 
  

   in 
  Nicaragua. 
  Two 
  years 
  later 
  two 
  of 
  the 
  Santa 
  Elena 
  bobbins 
  

   were 
  reported 
  " 
  faulty," 
  and 
  the 
  same 
  number 
  failed 
  at 
  

  

  N2 
  

  

  