﻿546 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  192 
  9 
  

  

  States, 
  Canada, 
  and 
  Mexico 
  must 
  be 
  equipped 
  with 
  the 
  M. 
  C. 
  B. 
  or 
  

   Janney 
  coupler. 
  

  

  Until 
  the 
  time 
  of 
  his 
  death, 
  in 
  1912, 
  Janney 
  was 
  constantly 
  experi- 
  

   menting 
  and 
  devising 
  improvements 
  for 
  the 
  coupler, 
  particularly 
  foi 
  

   passenger 
  cars. 
  For 
  years, 
  even 
  after 
  his 
  royalties 
  ceased, 
  he 
  had 
  

   expert 
  mechanics 
  in 
  his 
  private 
  employ, 
  he 
  visualizing 
  his 
  ideas 
  in 
  little 
  

   wooden 
  models 
  carved 
  with 
  a 
  pen 
  knife 
  and 
  they 
  converting 
  them 
  into 
  

   finished 
  models 
  of 
  wood 
  and 
  metal. 
  One 
  of 
  each 
  of 
  these 
  form 
  most 
  

   interesting 
  and 
  valuable 
  accessions 
  in 
  the 
  railroad 
  exhibits 
  in 
  the 
  Na- 
  

   tional 
  Museum. 
  With 
  them 
  is 
  a 
  third 
  model 
  of 
  the 
  coupler 
  improve- 
  

   ment 
  devised 
  and 
  patented 
  by 
  Janney's 
  son 
  Robert. 
  The 
  latter 
  grew 
  

   up 
  with 
  couplers 
  all 
  about 
  him 
  and 
  eventually 
  became 
  associated 
  with 
  

   one 
  of 
  the 
  large 
  coupler 
  manufacturers, 
  continuing 
  in 
  this 
  special 
  field 
  

   until 
  his 
  death 
  in 
  1923. 
  

  

  V. 
  THE 
  BIRTH 
  OF 
  THE 
  TROLLEY 
  CAR 
  

  

  For 
  20 
  years 
  prior 
  to 
  his 
  election 
  as 
  first 
  Secretary 
  of 
  the 
  Smithsonian 
  

   Institution, 
  Joseph 
  Henry 
  engaged 
  in 
  electrical 
  researches, 
  first 
  at 
  

   the 
  Albany 
  Academy, 
  where 
  he 
  was 
  professor 
  of 
  mathematics 
  and 
  

   physics 
  from 
  1827 
  to 
  1833, 
  and 
  then 
  at 
  Princeton 
  University, 
  where 
  

   he 
  held 
  the 
  chair 
  of 
  professor 
  of 
  natural 
  philosophy 
  from 
  1833 
  to 
  

   1846. 
  Early 
  in 
  his 
  teaching 
  career 
  Henry 
  used 
  apparatus 
  of 
  his 
  

   own 
  construction 
  to 
  illustrate 
  electromagnetic 
  reactions. 
  In 
  1825 
  

   William 
  Sturgeon, 
  of 
  England, 
  had 
  made 
  the 
  first 
  efficient 
  electro- 
  

   magnet, 
  capable 
  of 
  sustaining 
  9 
  pounds, 
  to 
  illustrate 
  the 
  relationship 
  

   of 
  the 
  earth's 
  magnetism 
  to 
  battery 
  currents. 
  Beginning 
  where 
  

   Sturgeon 
  left 
  off, 
  Henry 
  developed 
  fundamental 
  principles 
  and 
  laws 
  

   upon 
  which 
  the 
  modern 
  science 
  of 
  electromagnetism 
  rests. 
  He 
  was 
  

   the 
  first 
  to 
  insulate 
  wire 
  for 
  the 
  magnetic 
  coil; 
  he 
  invented 
  the 
  

   "spool" 
  or 
  "bobbin" 
  winding; 
  he 
  discovered 
  the 
  necessary 
  law 
  of 
  

   proportion 
  between 
  the 
  electromotive 
  force 
  in 
  the 
  battery 
  and 
  the 
  

   resistance 
  of 
  the 
  magnet. 
  He 
  thus 
  worked 
  out 
  for 
  the 
  first 
  time 
  

   the 
  differing 
  functions 
  of 
  two 
  entirely 
  different 
  kinds 
  of 
  electro- 
  

   magnets, 
  the 
  one 
  surrounded 
  by 
  numerous 
  coils 
  of 
  no 
  great 
  length, 
  

   the 
  other 
  surrounded 
  by 
  a 
  continuous 
  coil 
  of 
  very 
  great 
  length. 
  The 
  

   former 
  revolutionized 
  the 
  feeble 
  electromagnet 
  of 
  Sturgeon, 
  and 
  by 
  

   it 
  Henry 
  was 
  able 
  to 
  lift 
  3,500 
  pounds, 
  as 
  compared 
  to 
  Sturgeon's 
  

   maximum 
  lift 
  of 
  9 
  pounds. 
  The 
  latter 
  was 
  entirely 
  Henry's 
  inven- 
  

   tion 
  and 
  made 
  possible 
  for 
  the 
  first 
  time 
  the 
  transmission 
  of 
  a 
  current 
  

   over 
  a 
  great 
  distance 
  with 
  little 
  loss. 
  Every 
  electrical 
  dynamo 
  or 
  

   motor 
  now 
  uses 
  the 
  electromagnet 
  in 
  practically 
  the 
  form 
  in 
  which 
  

   Henry 
  left 
  it 
  in 
  1829. 
  

  

  Joseph 
  Henry's 
  concern 
  was 
  the 
  discovery 
  of 
  truth, 
  not 
  the 
  appli- 
  

   cation 
  of 
  his 
  discoveries. 
  The 
  officers 
  of 
  the 
  Penfield 
  Iron 
  Works, 
  

   at 
  Crown 
  Point, 
  N. 
  Y., 
  however, 
  prevailed 
  upon 
  him 
  to 
  make 
  them 
  

  

  