﻿Work 
  Measured 
  by 
  the 
  Discharge 
  of 
  Carbon 
  Dioxide. 
  241 
  

  

  in 
  foot-pounds 
  per 
  minute 
  or 
  horse-power,* 
  of, 
  preferably, 
  in 
  kgrm.-metres 
  

   per 
  second. 
  

  

  I 
  take 
  as 
  the 
  measure 
  of 
  physiological 
  efficiency 
  the 
  ratio 
  

  

  kgrm.-metres 
  per 
  second/cubic 
  centimetres 
  CO2 
  per 
  second, 
  

  

  i.e., 
  the 
  number 
  of 
  kgrm.-metres 
  per 
  1 
  c.c. 
  CO2 
  [or 
  by 
  its 
  reciprocal 
  

   C02/kgrm.-metre, 
  i.e., 
  the 
  physiological 
  cost 
  in 
  CO2 
  of 
  1 
  kgrm.-metre 
  of 
  work]. 
  

  

  The 
  expression 
  kgrm-metre/C0 
  2 
  is 
  further 
  simplified 
  by 
  conversion 
  of 
  the 
  

   CO2 
  value 
  into 
  its 
  equivalent 
  mechanical 
  value 
  in 
  kgrm.-metres. 
  For 
  this 
  

   conversion 
  I 
  take 
  the 
  factor 
  2*5, 
  which 
  gives 
  a 
  single 
  numerical 
  value 
  of 
  

   physiological 
  efficiency. 
  Or 
  the 
  value 
  of 
  the 
  kgrm.-metre/ 
  CO2 
  ratio 
  

   multiplied 
  by 
  40 
  gives 
  at 
  once 
  in 
  per 
  100 
  the 
  " 
  efficiency 
  " 
  value 
  of 
  the 
  

   subject. 
  

  

  For 
  example, 
  a 
  given 
  subject 
  (A. 
  D. 
  W,), 
  working 
  for 
  two 
  minutes 
  at 
  the 
  

   net 
  cost 
  of 
  25 
  c.c. 
  C0 
  2 
  per 
  second 
  has 
  a 
  kgrm.-metre/ 
  C0 
  2 
  ratio 
  = 
  20/25 
  = 
  0"8, 
  

   and 
  an 
  efficiency 
  = 
  - 
  8 
  x 
  40 
  = 
  32 
  per 
  cent. 
  His 
  CO2/ 
  kgrm.-metre 
  ratio 
  is 
  

   25/20, 
  or 
  1 
  kgrm.-metre 
  of 
  his 
  work 
  (at 
  the 
  rate 
  given) 
  costs 
  1*25 
  c.c. 
  of 
  CO2 
  

  

  On 
  this 
  principle, 
  a 
  further 
  calibration 
  of 
  Labourer 
  No. 
  1 
  is 
  subjoined: 
  

   1st, 
  by 
  staircase 
  work, 
  and 
  2ndly, 
  by 
  walking 
  on 
  a 
  horizontal 
  path. 
  

  

  September 
  6th, 
  1919. 
  — 
  Labourer 
  No. 
  1. 
  Weight, 
  87'2 
  kgrm. 
  ; 
  staircase 
  

   ergometry, 
  three 
  ascents 
  of 
  a 
  20-metre 
  staircase 
  ; 
  samples 
  of 
  expired 
  air 
  

   collected 
  during 
  the 
  last 
  5 
  metres 
  of 
  each 
  ascent, 
  i.e., 
  during 
  20 
  to 
  

   21 
  sees. 
  ; 
  descents 
  by 
  lift 
  in 
  30 
  to 
  40 
  sec. 
  

  

  

  Time 
  of 
  

   sample 
  

   (seconds). 
  

  

  Ventilation. 
  

  

  CO 
  t 
  

   per 
  cent. 
  

  

  C0 
  2 
  , 
  

   c.c. 
  per 
  

   sec. 
  

  

  Litres. 
  

  

  c.c. 
  per 
  sec. 
  

  

  First 
  trial 
  — 
  ■ 
  

  

  Normal 
  at 
  rest 
  

  

  1st 
  ascent 
  

  

  2nd 
  „ 
  

  

  3rd 
  „ 
  

  

  Work 
  per 
  sec. 
  = 
  ^ 
  ^ 
  

   8 
  

  

  Cost 
  of 
  work 
  per 
  sec. 
  = 
  

  

  Kl^L_2127_ 
  . 
  6 
  

   C0 
  2 
  3210 
  

  

  COj/Kg.-M. 
  = 
  1 
  -515 
  ( 
  

  

  60 
  

   18 
  

   21 
  

  

  20 
  

  

  x20 
  - 
  21-27 
  

   2 
  

  

  36-1-4 
  = 
  I 
  

   5 
  x 
  40 
  = 
  26-4 
  

   = 
  8'4 
  Kals). 
  

  

  8 
  

   11 
  

  

  20 
  

   20 
  

  

  Kg.-M. 
  

  

  52 
  1 
  ec. 
  CO- 
  2 
  

   per 
  cent, 
  efl 
  

  

  133 
  

   611 
  

   952 
  

   1000 
  

  

  iciency. 
  

  

  3- 
  

  

  4- 
  

   3-8 
  

   3-6 
  

  

  4-0 
  

   24 
  -4 
  

   36 
  -2 
  

   36 
  -0 
  

  

  * 
  1 
  horse-power 
  

   per 
  second. 
  

  

  =■ 
  550 
  foot-pounds 
  per 
  minute, 
  or 
  approximately 
  75 
  kgrm.-metres 
  

  

  u 
  2 
  

  

  