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  THE 
  

  

  AMERICAN 
  JOURNAL 
  OF 
  SCIENCE 
  

  

  [THIRD 
  SERIES.] 
  

  

  Art. 
  VI. 
  — 
  On 
  the 
  Relation 
  of 
  Gravity 
  to 
  Continental 
  Eleva- 
  

   tion 
  ; 
  by 
  T. 
  C. 
  Mendenhall. 
  

  

  [Read 
  at 
  the 
  November 
  meeting 
  of 
  the 
  N. 
  A. 
  S.] 
  

  

  Nearly 
  all 
  of 
  the 
  earlier 
  determinations 
  of 
  the 
  force 
  of 
  

   gravity 
  in 
  the 
  United 
  States 
  were 
  made 
  in 
  the 
  vicinity 
  of 
  the 
  

   Atlantic 
  Ocean, 
  not 
  more 
  than 
  one 
  or 
  two 
  stations 
  in 
  the 
  

   Mississippi 
  Yalley 
  having 
  been 
  occupied 
  previous 
  to 
  the 
  year 
  

   1890. 
  A 
  determination 
  had, 
  however, 
  been 
  made 
  on 
  the 
  

   Pacific 
  Coast, 
  at 
  San 
  Francisco, 
  and 
  pendulums 
  had 
  been 
  

   swung 
  for 
  the 
  same 
  purpose 
  on 
  the 
  summit 
  of 
  Mount 
  Hamil- 
  

   ton, 
  at 
  the 
  Lick 
  Observatory. 
  

  

  The 
  development 
  in 
  the 
  Coast 
  and 
  Geodetic 
  Survey 
  of 
  the 
  

   system 
  of 
  gravitation 
  measure 
  by 
  means 
  of 
  half 
  -second 
  pendu- 
  

   lums, 
  to 
  which 
  reference 
  has 
  already 
  been 
  made 
  in 
  previous 
  

   papers, 
  made 
  it 
  possible, 
  at 
  a 
  vastly 
  less 
  expenditure 
  of 
  time 
  

   and 
  labor, 
  to 
  execute 
  an 
  extensive 
  series 
  of 
  gravity 
  determina- 
  

   tions 
  as 
  near 
  as 
  might 
  be 
  along 
  the 
  39th 
  parallel, 
  extending 
  

   from 
  ocean 
  to 
  ocean, 
  thus 
  following 
  nearly 
  the 
  line 
  of 
  the 
  

   great 
  trans-continental 
  arc. 
  

  

  In 
  the 
  year 
  1893, 
  an 
  officer 
  of 
  the 
  French 
  Geographic 
  corps, 
  

   Colonel 
  George 
  Deflorges, 
  widely 
  known 
  for 
  his 
  investigations 
  

   in 
  connection 
  with 
  gravitation, 
  visited 
  this 
  country, 
  bringing 
  

   with 
  him 
  pendulums 
  which 
  he 
  had 
  swung 
  at 
  several 
  European 
  

   stations, 
  for 
  the 
  purpose 
  of 
  occupying 
  the 
  fundamental 
  sta- 
  

   tions 
  of 
  the 
  Coast 
  and 
  Geodetic 
  Survey, 
  and 
  observing 
  at 
  a 
  

   few 
  isolated 
  points 
  which 
  might 
  be 
  available 
  during 
  the 
  period 
  

   of 
  his 
  stay. 
  Colonel 
  Defforges 
  swung 
  his 
  pendulums 
  at 
  several 
  

   stations 
  previously 
  occupied 
  by 
  Coast 
  Survey 
  observers, 
  and 
  at 
  

  

  Am. 
  Jour. 
  Sci.— 
  Third 
  Series, 
  Vol. 
  XLIX, 
  No. 
  290.— 
  Feb 
  , 
  1895. 
  

   6 
  

  

  