﻿548 
  ANNUAL 
  EEPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1929 
  

  

  * 
  

  

  chanced 
  to 
  hear 
  the 
  wonderful 
  tale 
  of 
  the 
  magnet. 
  It 
  was 
  especially 
  

   interesting 
  to 
  them 
  for 
  they 
  had 
  planned 
  a 
  lecture 
  tour 
  on 
  scientific 
  

   subjects 
  illustrated 
  by 
  experiments 
  and 
  they 
  were 
  looking 
  for 
  good 
  

   features 
  tp 
  add 
  to 
  their 
  repertory. 
  Davenport 
  traveled 
  to 
  Crown 
  

   Point 
  to 
  see 
  the 
  magnet, 
  but 
  without 
  success. 
  Again 
  in 
  December, 
  

   1833, 
  he 
  went 
  to 
  Crown 
  Point 
  to 
  purchase 
  iron, 
  and 
  this 
  time 
  he 
  

   saw 
  the 
  magnet 
  and 
  was 
  given 
  an 
  exhibition 
  of 
  its 
  powers. 
  

  

  The 
  first 
  question 
  that 
  came 
  into 
  Davenport's 
  mind 
  concerned 
  

   the 
  probable 
  eft'ect 
  on 
  the 
  magnet 
  if 
  the 
  current 
  supply 
  were 
  alter- 
  

   nately 
  made 
  and 
  broken. 
  He 
  asked 
  if 
  he 
  might 
  try 
  it. 
  When 
  per- 
  

   mission 
  was 
  refused 
  he 
  used 
  the 
  $18 
  he 
  had 
  brought 
  along 
  to 
  buy 
  

   iron 
  and 
  purchased 
  the 
  magnet 
  instead. 
  He 
  now 
  answered 
  his 
  

   question 
  himself, 
  finding 
  that 
  as 
  rapidly 
  as 
  he 
  could 
  make 
  and 
  break 
  

   the 
  current 
  supply 
  the 
  magnet 
  was 
  charged 
  and 
  discharged. 
  He 
  

   realized 
  at 
  once 
  that 
  here 
  was 
  an 
  available 
  source 
  of 
  power. 
  Forget- 
  

   ful 
  that 
  his 
  wife 
  and 
  children 
  depended 
  on 
  his 
  blacksmithing 
  for 
  

   their 
  daily 
  bread, 
  he 
  and 
  Smalley 
  began 
  experiments 
  to 
  develop 
  a 
  

   machine 
  employing 
  electromagnetism 
  as 
  a 
  power 
  agent. 
  

  

  In 
  spite 
  of 
  his 
  wide 
  scientific 
  reading 
  Davenport 
  was 
  not 
  a 
  sub- 
  

   scriber 
  to 
  Silliman's 
  American 
  Journal 
  of 
  Science 
  and, 
  therefore, 
  was 
  

   not 
  aware 
  of 
  just 
  what 
  had 
  been 
  done 
  up 
  to 
  that 
  time 
  by 
  others. 
  The 
  

   same 
  year 
  (1831) 
  that 
  Henry 
  amazed 
  the 
  world 
  with 
  his 
  electro- 
  

   magnet 
  improvements 
  he 
  published 
  another 
  paper 
  commencing 
  with 
  

   these 
  words: 
  "I 
  have 
  lately 
  succeeded 
  in 
  producing 
  motion 
  in 
  a 
  little 
  

   machine 
  by 
  a 
  power 
  which 
  I 
  believe 
  has 
  never 
  before 
  been 
  applied 
  

   in 
  mechanics 
  — 
  by 
  magnetic 
  attraction 
  and 
  repulsion. 
  Not 
  much 
  

   importance, 
  however, 
  is 
  attached 
  to 
  the 
  invention, 
  since 
  the 
  article, 
  

   in 
  its 
  preseat 
  state 
  can 
  only 
  be 
  considered 
  a 
  philosophical 
  toy; 
  al- 
  

   though 
  in 
  the 
  progress 
  of 
  discovery 
  and 
  invention 
  it 
  is 
  not 
  impossible 
  

   that 
  the 
  same 
  principle, 
  or 
  some 
  modification 
  of 
  it 
  on 
  a 
  more 
  extended 
  

   scale, 
  may 
  hereafter 
  be 
  applied 
  to 
  some 
  useful 
  purpose." 
  That 
  

   "philosophical 
  toy" 
  now 
  forms 
  one 
  of 
  the 
  valuable 
  objects 
  in 
  the 
  

   electrical 
  collections 
  of 
  the 
  National 
  Museum, 
  In 
  the 
  Annals 
  of 
  

   Electricity, 
  Magnetism, 
  and 
  Chemistry 
  for 
  1834, 
  T. 
  Edmondson, 
  jr., 
  

   of 
  Baltimore, 
  Md., 
  published 
  the 
  first 
  account 
  of 
  his 
  apparatus 
  to 
  pro- 
  

   duce 
  continuous 
  rotary 
  motion 
  by 
  the 
  agency 
  of 
  an 
  electromagnet. 
  

  

  Ignorant 
  of 
  these 
  eft'orts, 
  Davenport 
  and 
  Smalley 
  worked 
  the 
  greater 
  

   part 
  of 
  1834. 
  They 
  started 
  with 
  a 
  permanently 
  magnetized 
  bar 
  sup- 
  

   ported 
  at 
  its 
  center 
  like 
  a 
  magnetic 
  needle. 
  By 
  placing 
  an 
  electro- 
  

   magnet 
  approximately 
  at 
  the 
  edge 
  of 
  the 
  circle 
  described 
  by 
  the 
  mag- 
  

   net 
  and 
  then 
  breaking 
  the 
  circuit 
  by 
  hand 
  at 
  properly 
  timed 
  intervals, 
  

   they 
  found 
  that 
  they 
  could 
  keep 
  the 
  bar 
  in 
  continuous 
  rotation. 
  

   From 
  this 
  they 
  progressed, 
  machine 
  by 
  machine, 
  until 
  by 
  December 
  

   they 
  completed 
  one 
  of 
  12 
  perm.anent 
  magnets 
  and 
  2 
  electromagnets 
  

   connected 
  through 
  a 
  form 
  of 
  commutator 
  consisting 
  of 
  wires 
  dipping 
  

  

  