80 SCIENCE PROGRESS 



This implies that a margin of 10 per cent, over all is allowed 

 for waste in cooking and serving. 



Calories or Units of Energy required 



Per day. Per week. 



Father 3,400 23,800 



Mother 2,750 19,250 



Boy 13 3,000 21,000 



Boy or girl 11 2,400 16,800 



Boy or girl 9 2,000 14,000 



Boy or girl 7 1,750 12,250 



Total .... 15,300 107,100 



The weekly supply of energy in food may therefore be 

 taken as 107,000 large calories. That is to say, the family 

 of six persons requires the equivalent in food of 4*5 men each 

 receiving 3,400 calories per day, or as it is usually expressed, 

 has a " man-value " of 4*5. 



There are many ways in which this calorie requirement 

 could be met in actual foods. In theory the number and 

 variety of ways are endless, but limits are set in practice by 

 the circumstances of the family and by the foods available 

 on the market. It seems, therefore, best to give instances of 

 how these requirements have been met in actual life by 

 labouring families under different circumstances. 



In the first place three instances are given of food 

 actually consumed by families of the labouring class having 

 a man-value of approximately 4*5. They are as follows : 

 (A) (man-value 4*4) based on statistics of food consumed by 

 agricultural families collected by Mr. Wilson Fox and pub- 

 lished by the Board of Trade in 1903 ; (B) (man-value 4*5 *) 

 based on similar statistics collected by the Board of Trade 

 regarding food consumed by urban working families and 

 published in 1904 ; (C) based on information collected in 191 7 

 by the War Emergency Committee and supplied to the Ministry 

 of Food. 



1 The actual man-value of these urban working-class families was estimated to 

 be equivalent to 4*14 men. The quantities of food per week in dietary B have 

 therefore been proportionately raised to meet the needs of a family of 4*5 men. 



