NORMALITY OF CHILDREN STUDIED. 37 



representing Holt's data and our own laboratory data 1 were obtained 

 by first plotting all the numerous measurements and then drawing 

 through the plotted points smoothed curves representing the general 

 trend. In each case these smoothed curves are really composite 

 curves representing the judgments of five members of the laboratory 

 staff, who were asked to sketch in on tracing paper their visualization 

 of the general trend. 



While no difficulty was experienced in securing sufficient data with 

 regard to foreign children from the classical researches of Vierordt and 

 others, special consideration must be given the measurements of 

 American children. One of the greatest difficulties in this connection 

 is the fact that most of the body-weight measurements of American 

 children, especially those above 5 years of age, include weight of 

 clothing, and this necessitates a rather uncertain correction for clothing. 

 In the data which we have selected, however, all measurements of 

 body-weight, and indeed height, were taken without clothing, with 

 one exception. Quetelet's measurements of weight involved weight 

 of clothing, but fortunately he corrected his values for the weight of 

 clothing worn by deducting one-eighteenth of the total weight for 

 males and one twenty-fourth for females. Consequently we feel 

 justified in using his values for comparison with our other data. 



Of special significance is our recalculation, averaging, and charting 

 of a series of figures compiled from the article by Gray, 2 who has very 

 carefully made most suitable selections and who cites only body- 

 weights without clothing. For children from 6 months to 4 years of 

 age Gray gives values from Crum 3 which are based upon 5,602 boys 

 and 4,821 girls. For children from 5 years to 20 years of age he gives 

 values received by him in a personal communication from Professor 

 Wood, of the Life Extension Institute. 4 In reporting Crum's figures, 

 Gray quotes him as inclined to think that the children measured by 

 him may be regarded "as somewhat super-normal, or above average," 

 since they were measured in connection with a "better baby contest," 

 a movement prompted by the committee on public health and instruc- 

 tion of the American Medical Association. The great majority of the 



1 The data for the ages, weights, and heights of our laboratory children are given in tables 26, 



27, and 28 (pp. 112, 116, and 120) in our subsequent discussion of basal metabolism. Addi- 

 tional data for 8 boys and 4 girls, for whom basal metabolism measurements are not avail- 

 able but for whom we have these physical measurements, are reported in tables 12 and 13 

 (pp. 54 and 58) in the discussion of anthropometric measurements. As will be explained 

 in detail later, all the individual measurements secured by us for weight, height, and age 

 were not used in plotting these charts, but the values were averaged to a certain extent. 

 Thus, a child was considered a new individual with an increase in age of 6 months, or with 

 an increase in weight of 1 kg. up to 10 kg. and of 10 per cent beyond 10 kg., and measure- 

 ments obtained on a child on two or three successive days or on days relatively close together 

 were often averaged as one value rather than being used separately. 



2 Gray and Gray, Boston Med. Surg. Journ., 1917, 177, p. 894. 



3 Crum, Quarterly Pub. Am. Statistical Assn., Sept., 1916, n. s., No. 115, vol. xv, Boston, pp. 



332-336. See also Gray and Gray, loc. cit., p. 895, table 2. 



4 Gray and Gray, loc. cit., p. 896, tables 3 and 4. 



