﻿AT 
  VARIOUS 
  PLACES 
  IN 
  THE 
  UNITED 
  STATES. 
  

  

  213 
  

  

  increase 
  in 
  the 
  dip, 
  and 
  although 
  the 
  differences 
  are 
  small, 
  they 
  are, 
  

   except 
  in 
  the 
  case 
  of 
  the 
  last 
  observation, 
  in 
  the 
  same 
  direction. 
  The 
  

   observation 
  made 
  in 
  1833 
  is 
  not 
  entirely 
  comparable 
  with 
  those 
  in 
  

   1834, 
  having 
  been 
  made 
  in 
  a 
  different 
  locality. 
  

  

  

  

  Observed 
  Dip. 
  

  

  

  

  

  

  No. 
  of 
  

   Series. 
  

  

  Nee- 
  

   dle. 
  

  

  

  Temp. 
  

   Fahr. 
  

  

  Date 
  of 
  Observa- 
  

   tions. 
  

  

  Observers. 
  

  

  Place 
  of 
  Obser- 
  

   vation. 
  

  

  Separate 
  

   Observs. 
  

  

  Mean. 
  

  

  1 
  

  

  No. 
  1 
  

  

  73°26'.4 
  

  

  

  

  April 
  15, 
  1833. 
  

  

  Professors 
  Courte- 
  

  

  Middle 
  of 
  plain. 
  

  

  

  No. 
  2 
  

  

  73 
  25.2 
  

  

  73°25'.8 
  

  

  

  11 
  A.M. 
  to 
  

   3 
  P.M. 
  

  

  nay 
  and 
  Henry. 
  

  

  

  2 
  

  

  No. 
  1 
  

  

  73 
  35.1 
  

  

  

  

  April 
  22, 
  1834. 
  

  

  E. 
  H. 
  Courtenay 
  & 
  "1 
  

  

  

  No. 
  2 
  

  

  73 
  35 
  .3 
  

  

  73 
  35.2 
  

  

  

  3 
  P.M. 
  

  

  A. 
  D. 
  Bache. 
  

  

  

  3 
  

  

  No. 
  1 
  

  

  73 
  35.1 
  

  

  

  81° 
  

  

  May 
  19, 
  1834. 
  

  

  E. 
  H. 
  Courtenay 
  & 
  

  

  

  

  No. 
  2 
  

  

  73 
  35.5 
  

  

  

  

  

  Assistant 
  Profes- 
  

  

  Brick 
  column 
  

  

  

  No. 
  1 
  

  

  73 
  37.3 
  

  

  73 
  36 
  .0 
  

  

  

  

  sor 
  Cram. 
  

  

  north 
  of 
  Pro- 
  

  

  4 
  

  

  No. 
  1 
  

  

  73 
  36 
  .6 
  

  

  

  65 
  

  

  June 
  3, 
  1834. 
  

  

  E. 
  H. 
  Courtenay. 
  

  

  [ 
  fessorCourte- 
  

  

  

  No. 
  2 
  

  

  73 
  36.4 
  

  

  73 
  36.5 
  

  

  

  

  

  nay's 
  house. 
  

  

  5 
  

  

  No. 
  1 
  

   No. 
  2 
  

  

  73 
  39.2 
  

   73 
  39.6 
  

  

  73 
  39 
  .4 
  

  

  90 
  

  

  July 
  9, 
  1834. 
  

  

  E. 
  H. 
  Courtenay. 
  

  

  

  6 
  

  

  No. 
  1 
  

  

  73 
  38 
  .7 
  

  

  73 
  38.7 
  

  

  

  July 
  14, 
  1834. 
  

  

  E. 
  H. 
  Courtenay. 
  

  

  Mean 
  of 
  2, 
  3, 
  4, 
  5, 
  6 
  : 
  73° 
  37'.2. 
  

  

  MAGNETIC 
  DIP 
  AT 
  PROVIDENCE, 
  RHODE 
  ISLAND 
  J 
  AND 
  AT 
  SPRINGFIELD 
  

  

  MASSACHUSETTS. 
  

  

  The 
  observations 
  at 
  both 
  these 
  places 
  were 
  made 
  under 
  disadvan- 
  

   tageous 
  circumstances. 
  Owing 
  to 
  the 
  brief 
  stay 
  which 
  it 
  was 
  possible 
  

   to 
  make 
  at 
  Providence, 
  the 
  observations 
  were 
  unavoidably 
  made 
  in 
  the 
  

   evening, 
  and 
  a 
  brisk 
  breeze 
  from 
  the 
  south 
  and 
  south 
  west 
  increased 
  

   the 
  difficulties 
  incident 
  to 
  that 
  time 
  of 
  the 
  day 
  : 
  but 
  for 
  the 
  kind 
  assist- 
  

   ance 
  of 
  President 
  Wayland, 
  and 
  of 
  Professor 
  Caswell, 
  the 
  observations 
  

   could 
  not 
  have 
  been 
  completed. 
  Needle 
  No. 
  1 
  only 
  was 
  observed. 
  

  

  The 
  place 
  of 
  observation 
  was 
  on 
  the 
  green 
  in 
  front 
  of 
  Brown 
  

   University, 
  and 
  just 
  in 
  rear 
  of 
  the 
  President's 
  house. 
  Latitude 
  

   41° 
  49' 
  25" 
  N. 
  and 
  longitude 
  71° 
  25' 
  26" 
  W. 
  

  

  At 
  Springfield 
  no 
  magnet 
  was 
  at 
  hand 
  for 
  reversing 
  the 
  poles 
  of 
  the 
  

   needle. 
  By 
  comparing, 
  however, 
  the 
  dip 
  observed 
  with 
  needle 
  No. 
  1 
  

   vol. 
  v 
  — 
  3 
  D 
  

  

  