﻿140 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  5 
  

  

  "As 
  we 
  contemplate 
  the 
  complexity 
  of 
  the 
  details 
  of 
  the 
  solar 
  surface, 
  the 
  

   constant 
  change 
  of 
  form 
  in 
  faculae, 
  spots, 
  and 
  prominences, 
  the 
  balance 
  

   of 
  forces 
  which 
  has 
  maintained 
  the 
  average 
  energy 
  of 
  the 
  Sun 
  so 
  constant 
  for 
  

   hundreds 
  of 
  millions 
  of 
  years 
  is 
  certainly 
  a 
  remarkable 
  fact 
  of 
  nature, 
  and 
  lends 
  

   indirect 
  support 
  to 
  the 
  postulation 
  of 
  an 
  enormous 
  duration 
  of 
  life 
  for 
  the 
  

   average 
  star. 
  

  

  "In 
  our 
  nearest 
  star, 
  then, 
  we 
  see 
  a 
  star 
  which 
  appears 
  to 
  be 
  about 
  an 
  aver- 
  

   age 
  star 
  in 
  surface 
  characteristics, 
  light 
  emission, 
  and 
  size. 
  It 
  is 
  a 
  fair 
  rep- 
  

   resentative 
  of 
  the 
  stars 
  in 
  general 
  ; 
  there 
  are 
  literally 
  tens 
  of 
  millions 
  of 
  copies 
  

   of 
  it 
  out 
  in 
  space. 
  This 
  great 
  heat-engine 
  is 
  pretty 
  certainly 
  a 
  billion, 
  and 
  

   more 
  probably 
  a 
  hundred 
  billion 
  years 
  old. 
  Certainly 
  for 
  200,000,000 
  years, 
  

   perhaps 
  for 
  a 
  billion 
  or 
  more 
  years, 
  it 
  has 
  not 
  varied 
  permanently 
  as 
  much 
  as 
  

   200° 
  C. 
  from 
  its 
  effective 
  temperature 
  of 
  perhaps 
  5,600° 
  C." 
  

  

  William 
  R. 
  Maxon, 
  Recording 
  Secretary. 
  

  

  