The Groicth of Children. 71 



the normal type. This ol)je(jtioii is deprived of whatever 

 weight it may have by extending the observations ovej* a con- 

 siderable length of time. It is probable that when the inves- 

 tigation is carried on, as in the i)reseiit instance, during the 

 greater part of a year, the effect of such disturbing influences 

 may be regarded as, to a great extent, eliminated, though a 

 series of investigations undertaken at intervals of several 

 years would be necessary to deiinitcly settle the question. 

 For a further discussion of this method of ascertaining the 

 rate of growth, the reader is referred to the statistical investi- 

 gations of Dr. B. A. Gould,* p. 115. 



From the averages given in Tables Nos. 1 and 2, Table 

 No. 3 was then computed, shewing the annual increase both 

 in height and weight of children of both sexes, and of the 

 above-mentioned parentage. In this table is also given in 

 the columns headed " pounds per inch " a series of figures 

 obtained by dividing the weight in pounds by the height in 

 inches, and showing what, for want of a better word, may be 

 called the "stoutness" of the children at different ages, etc. f 



In order to obtain a more adequate idea of the growth of 

 the children in this community than that furnished by the 

 average heights and weights, another set of tables was com- 

 puted, showing for every age the number of observations at 

 each height and weight. Tables of this sort for children of 

 American and of Irish parents, and for tlie whole number of 

 observations irrespective of nationality, are given at the end 



* Investigations in the AUlitiiry antl Anthropological Statistics of American Soldiers. By 

 Benjamin Apthorp Gould. New York. 18G9. 



t It will be noticed that in Tables Nos. 1 and 2 the ages are given " at the last birthday." 

 Hence, the avcraye a(je of the children thus grouped together will be six months greater 

 than the age given in the tables. For instance, 5 years G months is the average age of the 201 

 boys of American parentage, whose height is 41.74 inches, and whose weight is 41.20 pounds. 

 Now, since the figures in the columns headed annual increase, i« Table No. 3, are the dif- 

 ferences between the successive heights and weights in Tables Nos. 1 and 2, it is evident 

 that they express the yearly growth precisely at the age given in the table. For instance, 

 if the average height of the above-mentioned boys of 5^ years old is 41.74 inches, and that 

 of the boys of the same parentage, one year older, is 44.10 inches, then 2.36 inches is the 

 average annual increase in height of boys at G years of age. On the other hand, the figures, 

 in the columns of Table No. 3, headed pounds per inch, express (as in Tables Nos. 1 and 2) 

 the ratio of the weight to the height of the children whose age at last birthday is placed 

 opposite to them in the table. 



