October 28, 1920] 



NATURE 



285 



enables us to deal with the fact that workers vary 

 markedly in physical condition. An objection to 

 the use of a general average for all workers in 

 ail trades is that it is frequently found in practice 

 that a certain type of man tends to drift into one 

 type of occupation and a different type into another. 

 It is a case, in the majority of instances, of the 

 survival of the fittest; if a worker is not suited 

 to the trade he has selected he eventually seeks 

 another. But, in spite of this possible segrega- 

 tion — and nothing could be more simple than to 

 make definite allowances if these were required 

 — it is found that the general law of averages 

 can be applied with success. 



In order to determine the total daily output of 

 energy by any individual, to the cost of the in- 

 ternal work must be added the increment due to 

 the external work done. In spite of the widely 

 expressed belief that it is quite impossible to 

 correlate the daily work done by different types 

 of workers, let us say that of a postman, a dock 

 labourer, a bricklayer, and a trawler deck-hand, 

 nothing is more easy, provided the appropriate 

 tests are carried out. It is true that the amount 

 of energy spent in the form of external work 

 varies very markedly with the type of work per- 

 formed and the conditions under which it is 

 carried out. It may range from the low cost of 

 sedentary work in a warm office or workshop, to 

 the other extreme of hard manual labour under 

 unfavourable conditions in the open air. One of 

 the attempts at the classification of external work 

 is given in the report on food requirements by the 

 Food (War) Committee of the Royal Society. The 

 figures given are net daily (eight-hour) figures to 

 be added to the cost of the basal metabolism. 



Sedentary 

 Light work 

 .Moderate 

 Heavy ... 



Less than 400 Calories 

 400 to 700 „ 

 700 „ 1000 „ 



1 100 „ 2000 „ 



In certain types of work the 2000-Calorie limit 

 may be exceeded. 



Then, finally, there is the question oi" sex. Ex- 

 p>erimental work has definitely shown that the 

 basal metabolism of women is about 7 per cent, 

 below that of men, and, further, that, except in 

 the lightest forms of manual work, the amount of 

 extern.-il work performed is below that of men. It 

 is generally held that the total energy output of 

 women for the twenty-four hours is 17 per cent, 

 below that of men. This divergence between the 

 male and female metabolism can ultimately be re- 

 ferred back fo two simple factors : (1) the relative 

 weights, and (2) the relative proportion of muscle 

 in the two sexes. As regards the first, it is 

 common knowledge that the average woman 

 weighs less than the average man ; and, as re- 

 gards the second, it is equally well known that the 

 average woman is not so muscular as the average 

 man — the average muscle in the case of man 

 forms about 45 per cent, of the total weight, 

 whereas in the woman it forms only about 38 

 per cent. It therefore follows that the expcndi- 

 NO. 2661, VOL. 106] 



ture of energy will be greater in the case of the 

 male, making the assumption, of course, that each 

 worker, male and female, is working at his or 

 her optimum rate. 



It is to be regretted that in this class of in- 

 vestigation, although a certain amount of work 

 has been done, Britain has not played a prominent 

 part. Compared with the work carried out both on 

 the Continent and in the United States, the experi- 

 mental work here has been almost negligible. 

 The special apparatus and the facilities for such 

 research have been lacking. The Inter-Allied 

 Scientific Food Commission, which sat during the 

 later stages of the war, did recommend that a 

 special institute for such research should be 

 founded in each country, but, so far, nothing has 

 been done here. 



As regards the practical aspect of the question, 

 the investigations of Miss Lindsay and Miss 

 Ferguson in Glasgow have thrown considerable 

 light on the problem. Before the war, for example, 

 it was found that the average family in receipt of 

 il. per week could obtain, expending, it is true, 

 about 73 per cent, of the total income on food, 

 3163 Calories per "man"' per day, roughly at the 

 rate of 453 Calories per penny. Early in 1917 an 

 income of il. los. did not suffice. At present, 

 in a recent Government return (Labour Gazette, 

 September, 1920), it is shown that the cost of food 

 alone is 167 per cent, above pre-war level, and if 

 the overall expenditure be taken there is an in- 

 crease of 161 per cent. The following table, from 

 data kindly supplied by Miss Ferguson, gives a 

 good idea of the change in the cost of living 

 during the past six years : — 



Yield of Energy in Calories per id. Purchasable at 

 Glasgow: Retail Prices. 



Commoditv 

 Flank beef ... 

 Flank mullon 

 Bacon 

 Cheese 

 Milk 



Margarine ... 

 Bread 

 Flour 

 Oatmeal 

 Barley 



Split peas ... 

 Haricot lieans 

 LentiU 



Rice 



Sufjar 

 Polaloes 



1914 



'32 



'3» 

 256 

 241 



659 

 810 



U55 

 1512 

 825 

 827 

 640 

 648 

 815 

 930 

 542 



Nov., June, May, 

 1915 1916 1917 



99 9" 79 



88 



103 



June, 

 1915 



99 



88 



203 187 179 129 

 171 196 152 89 



— — — 90 



504 298 



Nov., F.b., 

 1917 1920 



88 



587 

 607 



7;o 



753 

 660 



552 

 640 



463 

 8>5 

 S31 

 542 



587 



607 572 405 



798 722 471 



850 814 331 



550 471 330 



414 325 325 



533 457 >«<> 



216 463 217 



815 652 466 



49is 372 347 



723 271 244 



99 

 107 

 100 

 III 



68 

 255 

 527 

 722 

 467 

 412 

 297 

 271 

 217 

 466 

 3'7 

 4J7 



74 

 95 

 95 

 83 

 49 

 298 



495 

 722 

 404 

 3'4 

 32s 

 406 



271 

 408 

 228 

 2S9 



July, Oct., 

 1930 1930 

 46 66 



- 7' 

 96 



94 

 60 



90 



89 



39 



298 277 



384 405 



722 510 



— 3*0 



3>4 3'4 



325 366 



457 582 



325 271 



233 251 



133 207 



'42 375 



In view of the fact that, of the weekly wage of 

 the workers earning ^os. a week or less, at 

 any rate of those with families, 50 to 60 per 

 cent, of the income is legitimately spent in the 

 purchase of food, it is suggested that the total 



1 A fmnily compotcH of futhrr, niolh«r, nnit children can b« r*duc«<l to 

 tCTm« of " man" by ihr ii«r of ■p^trontiiiie and well-Mlablithcil faclon. S« 

 Hoyal Socitly FomI Rrqtiiremtnlii Report. 



