﻿WHICH 
  IS 
  CONDENSED 
  ON 
  A 
  COLD 
  SURFACE. 
  303 
  

  

  Next, 
  let 
  these 
  values 
  be 
  substituted 
  in 
  the 
  formula 
  c=m 
  (/"—/'"), 
  which 
  

   then 
  becomes 
  c=397 
  (-27- 
  "2) 
  =2779 
  grains. 
  

  

  But 
  as 
  c 
  represents 
  the 
  weight 
  of 
  moisture 
  which 
  would 
  be 
  condensed 
  on 
  a 
  

   surface 
  of 
  100 
  square 
  inches 
  in 
  60 
  seconds, 
  and 
  we 
  require 
  to 
  know 
  the 
  quantity 
  

   which 
  would 
  be 
  condensed 
  on 
  a 
  surface 
  equal 
  to 
  *00786 
  of 
  a 
  square 
  inch 
  in 
  the 
  

   lapse 
  of 
  three 
  seconds, 
  it 
  will 
  be 
  necessary, 
  in 
  order 
  to 
  obtain 
  this 
  latter 
  result, 
  

  

  •00786 
  3 
  

   to 
  multiply 
  2779 
  grains, 
  the 
  value 
  of 
  c, 
  by 
  -jkk- 
  x 
  **, 
  which 
  gives 
  -000011 
  of 
  a 
  

  

  grain 
  as 
  the 
  weight 
  of 
  moisture 
  condensed 
  on 
  the 
  surface 
  of 
  the 
  rain-drop, 
  while 
  

   falling 
  through 
  437 
  feet. 
  

  

  Now, 
  as 
  the 
  original 
  weight 
  of 
  the 
  drop 
  was 
  0165 
  of 
  a 
  grain, 
  it 
  follows 
  that 
  

   the 
  weight 
  of 
  moisture 
  condensed 
  on 
  the 
  drop 
  was 
  to 
  the 
  weight 
  of 
  the 
  drop 
  

   itself 
  in 
  the 
  ratio 
  of 
  -000011 
  to 
  -0165, 
  that 
  is, 
  in 
  the 
  ratio 
  of 
  -00066 
  to 
  1. 
  

  

  But, 
  as 
  was 
  before 
  shewn, 
  the 
  hypothesis 
  assumes 
  the 
  ratio 
  of 
  these 
  quanti- 
  

   ties 
  to 
  be 
  that 
  of 
  -42 
  to 
  1. 
  

  

  Hence, 
  unless 
  there 
  be 
  some 
  fallacy 
  in 
  the 
  mode 
  of 
  arriving 
  at 
  the 
  conclusion, 
  

  

  •42 
  

   the 
  rate 
  of 
  condensation 
  assumed 
  by 
  the 
  hypothesis 
  is 
  ^kkqq 
  = 
  635 
  times 
  greater 
  

  

  than 
  the 
  rate 
  deduced 
  from 
  experiment. 
  

  

  VOL. 
  XX. 
  PART 
  II. 
  4 
  N 
  

  

  