﻿454 
  ON 
  THE 
  RELATIVE 
  HORIZONTAL 
  INTENSITIES 
  

  

  to 
  the 
  different 
  sets 
  according 
  to 
  the 
  method 
  before 
  explained, 
  we 
  

   have 
  for 
  the 
  mean 
  horizontal 
  intensity, 
  

  

  h" 
  = 
  .94705. 
  

   By 
  comparing 
  this 
  result 
  with 
  the 
  mean 
  of 
  the 
  observations 
  made 
  

   in 
  full 
  air, 
  it 
  will 
  be 
  seen, 
  that 
  in 
  determining 
  the 
  value 
  of 
  h" 
  the 
  first 
  

   series 
  of 
  observations 
  has 
  hardly 
  any 
  weight, 
  and 
  we 
  propose 
  in 
  the 
  

   cases 
  which 
  follow, 
  where 
  observations 
  were 
  made 
  by 
  both 
  methods, 
  

   to 
  omit 
  those 
  of 
  the 
  first 
  series 
  entirely. 
  In 
  no 
  one 
  of 
  the 
  cases 
  alluded 
  

   to 
  were 
  the 
  observations 
  of 
  the 
  first 
  series 
  as 
  numerous 
  as 
  at 
  New 
  

   York. 
  And 
  the 
  comparison 
  has 
  probably 
  been 
  carried 
  sufficiently 
  far 
  to 
  

   show 
  the 
  superior 
  value 
  of 
  the 
  results 
  in 
  rarefied 
  air 
  ; 
  the 
  comparisons 
  

   having 
  been 
  made 
  according 
  to 
  principles 
  involving 
  the 
  mean 
  error 
  to 
  

   which 
  the 
  methods 
  are 
  liable, 
  as 
  deduced 
  from 
  the 
  observations 
  them- 
  

   selves. 
  

  

  MAGNETIC 
  INTENSITY 
  AT 
  NEWPORT, 
  R. 
  I. 
  

  

  The 
  observations 
  at 
  Newport 
  were 
  made 
  during 
  a 
  visit 
  there 
  in 
  the 
  

   months 
  of 
  August 
  and 
  September 
  1835. 
  They 
  all 
  belong 
  to 
  the 
  

   Second 
  Series, 
  and 
  were 
  made 
  in 
  nearly 
  the 
  same 
  place, 
  and, 
  with 
  

   few 
  exceptions, 
  about 
  the 
  same 
  period 
  of 
  the 
  day. 
  The 
  results 
  with 
  

   all 
  three 
  of 
  the 
  needles 
  agree 
  very 
  nearly 
  ; 
  the 
  greatest 
  number 
  of 
  ob- 
  

   servations 
  having 
  been 
  made 
  with 
  needle 
  A, 
  and 
  the 
  least 
  with 
  No. 
  

   3 
  (B). 
  

  

  We 
  have 
  abridged 
  this 
  table 
  by 
  omitting 
  the 
  column 
  for 
  the 
  dura- 
  

   tion 
  of 
  the 
  observations. 
  

  

  v 
  

  

  