﻿Lord 
  Kelvin 
  : 
  The 
  Problem 
  of 
  

   Fig. 
  2. 
  

  

  O 
  R 
  5 
  R 
  4 
  R 
  3 
  R 
  2 
  R 
  L 
  

  

  D 
  1 
  Rj, 
  D 
  2 
  R 
  2 
  , 
  D., 
  R 
  8 
  , 
  D 
  4 
  R 
  4 
  , 
  D 
  5 
  R 
  5 
  , 
  are 
  density 
  curves, 
  corresponding 
  

   respectively 
  to 
  the 
  temperature 
  curves 
  T\ 
  R 
  x 
  , 
  T 
  2 
  R 
  2 
  , 
  T 
  3 
  R 
  3 
  , 
  T 
  4 
  R 
  4 
  , 
  

   T 
  6 
  R 
  6 
  , 
  of 
  figure 
  1. 
  

  

  