﻿ARTIFICIAL 
  COLD 
  

  

  By 
  Gordon 
  B. 
  Wilkes 
  

  

  [With 
  3 
  plates] 
  

  

  The 
  appearance 
  of 
  refrigerating 
  machinery 
  for 
  domestic 
  use 
  has 
  

   created 
  among 
  laymen 
  an 
  abiding 
  interest 
  in 
  the 
  mechanical 
  methods 
  

   of 
  artificial 
  cooling. 
  Domestic 
  refrigeration 
  of 
  one 
  kind 
  or 
  another 
  

   is 
  here 
  to 
  stay 
  and 
  it 
  is 
  probable 
  that 
  an 
  extensive 
  development 
  of 
  

   cooling 
  and 
  ventilating 
  machinery 
  for 
  the 
  home 
  is 
  just 
  around 
  the 
  

   corner. 
  Already 
  many 
  of 
  our 
  theaters 
  and 
  public 
  halls 
  have 
  installed 
  

   devices 
  for 
  cooling 
  the 
  air 
  during 
  the 
  warm 
  months, 
  and 
  only 
  a 
  short 
  

   time 
  ago 
  a 
  combined 
  heating 
  and 
  air 
  coohng 
  unit 
  was 
  advertised 
  for 
  

   private 
  residences. 
  If 
  the 
  temperature 
  of 
  our 
  living 
  quarters 
  drops 
  

   8° 
  or 
  10° 
  to 
  around 
  60° 
  F., 
  we 
  feel 
  uncomfortable 
  and 
  start 
  the 
  heating 
  

   system; 
  but 
  if 
  a 
  warm 
  day 
  arrives 
  in 
  summer 
  with 
  a 
  temperature 
  

   20° 
  or 
  30° 
  above 
  70° 
  F., 
  we 
  are 
  uncomfortable 
  because 
  we 
  have 
  had 
  

   no 
  easy 
  means 
  of 
  cooling 
  the 
  air. 
  I 
  can 
  see 
  no 
  reason 
  why, 
  during 
  

   the 
  next 
  few 
  years, 
  it 
  will 
  not 
  become 
  a 
  rather 
  common 
  practice 
  in 
  

   the 
  more 
  expensive 
  homes 
  to 
  have 
  some 
  means 
  of 
  cooling 
  the 
  air 
  in 
  

   summer 
  as 
  well 
  as 
  a 
  means 
  of 
  heating 
  it 
  to 
  a 
  comfortable 
  temperature 
  

   during 
  winter. 
  

  

  Some 
  fifty-odd 
  years 
  ago, 
  Lord 
  Kelvin 
  (Sir 
  William 
  Thomson) 
  

   demonstrated, 
  by 
  means 
  of 
  a 
  simple 
  lecture-table 
  experiment, 
  that 
  

   the 
  sensation 
  of 
  cold 
  was 
  a 
  purely 
  relative 
  matter. 
  He 
  placed 
  three 
  

   basins 
  of 
  water 
  on 
  the 
  table: 
  one 
  hot, 
  one 
  ice 
  cold, 
  and 
  the 
  third 
  at 
  

   room 
  temperature. 
  Placing 
  his 
  right 
  hand 
  in 
  the 
  hot 
  water 
  and 
  his 
  

   left 
  m 
  the 
  cold 
  water 
  for 
  a 
  few 
  moments, 
  he 
  quickly 
  transferred 
  both 
  

   hands 
  to 
  the 
  basin 
  with 
  water 
  at 
  room 
  temperature. 
  In 
  attempting 
  

   to 
  describe 
  the 
  sensation 
  he 
  was 
  forced 
  to 
  conclude 
  that 
  either 
  his 
  

   left 
  hand 
  or 
  his 
  right 
  hand 
  was 
  deceiving 
  him, 
  for 
  the 
  water 
  felt 
  cold 
  

   to 
  his 
  right 
  and 
  warm 
  to 
  his 
  left 
  hand. 
  Since, 
  therefore, 
  the 
  sensation 
  

   of 
  cold 
  is 
  largely 
  a 
  relative 
  matter, 
  we 
  shall 
  assume 
  for 
  our 
  purposes 
  

   that 
  cold 
  signifies 
  any 
  temperature 
  below 
  70° 
  F., 
  ordinary 
  room 
  tem- 
  

   perature. 
  Let 
  us 
  also 
  agree 
  to 
  understand 
  that 
  all 
  of 
  the 
  temperatures 
  

   referred 
  to 
  are 
  in 
  degrees 
  on 
  the 
  Fahrenheit 
  scale, 
  the 
  one 
  we 
  use 
  for 
  

   most 
  work 
  outside 
  the 
  laboratory, 
  

  

  ' 
  Reprinted 
  by 
  permission 
  from 
  Tiie 
  Technology 
  Review, 
  March, 
  1929. 
  

  

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