COMPLIMENTS OF THE WRITER. 
THE GROWTH OF CHILDREN, 
STUDIED BY 
GALTON’S METHOD OF PERCENTILE GRADES, 
H. P. BOWDITCH, M.D., 
PROFESSOR OF PHYSIOLOGY, HARVARD MEDICAL SCHOOL. 
Reprinted from the Twenty-second Annual Report of the State Board of Health of Massachusetts THE GROWTH OF CHILDREN, 
STUDIED BY 
GALLON'S METHOD OF PERCENTILE GRADES, 
By H. P. BOWDITCH, M.D., 
PROFESSOR OF PHYSIOLOGY, HARVARD MEDICAL SCHOOL. 
Reprinted from the Twenty-second Annual Report of the State Board of Health of 
Massachusetts. Boston, 1891. THE GEOWTH OF CHILDEEN, 
STUDIED BY 
GALTON’S METHOD OF PERCENTILE GRADES, 
H. r. Bowditch, M.D., 
Professor of Physiology, Harvard 3Tedical School. 
In the last report of the Massachusetts State Board of 
Health the advantages of discussing statistical data by Gal- 
ton’s method * of percentile grades were explained and illus- 
trated in a paper entitled “ The Physique of Women in 
Massachusetts.” The value of the method in anthropomet- 
rical work seemed so obvious that it has been thought desir- 
able to apply it to the large body of observations on the 
height and weight of Boston school children which formed 
the basis of an article on “The Growth of Children,” pub- 
lished by the Board of Health in 1877. 
In this article, at the suggestion of Mr. Charles Roberts, 
tables were given showing the distribution of the observa- 
tions ; i.e., the number of individuals at each age whose 
height was recorded at each successive inch or whose weight 
fell within successive groups of four pounds each. From 
these tables (tables 4 to 15 of the above-mentioned article) 
it was easy to calculate the values at the various percentile 
grades. For example, it appears from Table 4 that the 
heights of 848 boys between five and six years old were 
distributed as shown in the following table : 
See “ Galton, Natural Inheritance,” London, McMillan & Co., 1889. 480 
STATE BOARD OF HEALTH. [Pub. Doc. 
Distribution of Observations on Heights of Boston School-boys. Age at 
Last Birthday Five Years. 
Inches. 
Number of 
observations. 
Inches, 
Number of 
observations. 
Inches. 
Number of 
observations. 
47 
4 
41 
190 
35 
1 
46 
8 
40 
149 
34 
- 
45 
20 
39 
79 
33 
- 
44 
62 
38 
42 
32 
- 
43 
119 
37 
17 
31 
- 
42 
149 
36 
7 
30 
1 
Total number of observations, . 
848 
In this table it will be seen that five percent., for instance, 
of the total number of observations is 42.4. Now since the 
observations corresponding to each successive inch include 
all the measurements between that inch and the next inch 
above, it is evident that there are 1 + I+7 +l7 = 26 individ- 
uals less than 38 inches in height and 1 +l+ 7 + 17+42 6B 
individuals less than 39 inches in height. Since, therefore, 
42.4 lies between 26 and, 68 it follows that the height below 
which five per cent, of the observations fall must be between 
38 and 39 inches. The exact height can readily be calcu- 
lated by interpolation. Thus the fraction of an inch to be 
added to 38 to give the required height is obtained by dividing 
16.4 (7.e., 42.4 26) by 42 (7.e., the number of observa- 
tions between 38 and 39 inches). This fraction is 0.39, and, 
therefore, 38.39 inches is the height below which five per 
cent, and above which ninety-five per cent, of the observa- 
tions fall; i.e., it is the value of the five per cent, grade. 
In this way tables 1 to 12 have been calculated from tables 
4to 15 inclusive of the original article. These tables show 
the heights and weights of Boston school children of both 
sexes and various ages at percentile grades varying from five 
per cent, to ninety-five per cent. Separate tables are, more- 
over, given for children of American parentage, Irish parent- 
age, and for the whole number of observations irrespective of 
nationality. The values are given in both the English and 
the metric system of weights and measures, and in the last No. 34.] 
THE GROWTH OF CHILDREN. 
481 
column of each table are to be found the average heights 
and weights of children of each age as given in the original 
article. 
The conclusions which may be drawn from a study of these 
tables will be best understood after an examination of the 
curves which have been constructed from them, and as a 
preliminary to this study it will be well to consider briefly 
the general character of curves representing values at various 
percentile grades. STATE BOARD OE HEALTH. 
[Pub. Doc. 
TABLES SHOWING HEIGHTS AND WEIGHTS, AMERICAN, IRISH AND TOTAL, AT PERCENTILE GRADES. 
Table No. 1. Calculated from Table 4 of Original Article. 
Heiahts of Boston School-hoys irrespective of Nationality. 
Number 
Values at the Following Percentile 
Grades. 
Average. 
Age at Last Bibthdat. 
of 
Observa- 
tions. 
Measure- 
ment. 
5 1 
Per Cent, j 
10 
Per Cent. 
SO 1 30 
Per Cent. Per Cent.j 
40 
Per Cent. 
50 
Per Cent. 
60 ; 70 
Per CentJ Per Cent. 
80 
Per Cent. 
1 
90 
Per Cent. 
95 
Per Cent. 
Five, 
Six, 
848 
1,258 
inch, 
c. m., 
inch, 
38.39 
97.5 
40.66 
103.3 
39.21 
99.6 
41.43 
105,2 
40.15 
102.0 
42.31 
107.4 
40.72 
103.4 
42.89 
108.9 
41.23 
104.7 
43.39 
110.2 
41.67 
105,8 
43.87 
111.4 
42.15 
107.1 
44.37 
112.7 
42.72 ! 
108,6 
44.86 1 
113,9 
43.36 
110.1 
45.54 
115.7 
44.15 
112.1 
46.49 
118.1 
44.83 
113.9 
47.13 
119.7 
41.57 
105.6 
43.75 
111.1 
Seven, 
1,419 
inch, 
42.48 
107.9 
43.27 
109.9 
44.20 
112T.3 
44.76 
113.7 
45.31 
115.1 
45.83 
116,4 
46.36 
117.8 
46.88 ! 
119.1 
47.55 
120.8 
48.48 
123.1 
49.27 
125.1 
45.74 
126.2 - 
Eight, 
Nine, 
1,481 
1,437 
inch, 
c. m., 
inch, 
44.46 
112.9 
46.41 
117.9 
45.24 
114,9 
47.18 
119,8 
46.15 
117.2 
48.04 
122.0 
46.81 
118,9 
48.70 
123.7 
47.35 
120,3 
49.27 
125.1 
47.84 
121,5 
49.77 
126,4 
48.36 
122.8 
50.30 
127.8 
48.90 
124.2 
50.87 
129.2 
49.61 
126.0 
51.60 
131.1 
50.58 
128.5 
52.61 
133.6 
51.42 
130,6 
53.46 
135.8 
47.76 
121.3 
49.69 
126.2 
Ten 
1,363 
inch, 
48.11 
122.2 
48.98 
124.4 
49.77 
126.4 
50.45 
128.1 
51.10 
129.8 
51.73 
131.4 
52.34 
132.9 
52.94 
134.5 
53.76 
136.6 
54.85 
139.3 
55.83 
141,8 
51.68 
131.3 
Eleven, 
1,293 
inch, 
49.47 
125.7 
50.32 
127.8 
51.30 
130.3 
52.08 
132.3 
52.75 
134,0 
53.40 
135.6 
54.04 
137.3 
54.73 
139,0 
55.50 
141.0 
56.54 
143.6 
57.00 
146.0 
53.33 
135,4 
Twelve 
1,253 
inch, 
51.10 
129.8 
51.96 
132.0 
53.07 
134.8 
53.78 
136.6 
54.46 
138.3 
55.11 
140.0 
55.75 
141.6 
56.46 
143,4 
57.36 
145.7 
58.75 
149.2 
59 .S8 
152.1 
55.11 
140.0 
Thirteen, 
1,160 
inch, 
52.62 
133.7 
53.58 
136.1 
54.81 
139.2 
55.69 
141.5 
56.37 
143.2 
56.98 
144.7 
57.84 
146.9 
58.75 
149.2 
59.80 
151.9 
61.47 
156.1 
62.73 
159.3 
57.21 
145.3 
Fourteen, 
908 
inch, 
54.57 
138.6 
55.66 
141,4 
57.13 
145.1 
58.07 
147.5 
58.78 
149.3 
59.60 
j 151.4 
60.48 
153.6 
61.51 
156.2 
62.80 
159.5 
64.61 
164.1 
65 89 
167,4 
59.88 
152.1 
Fifteen, 
636 
inch, 
56.55 
143.6 
58.07 
147,5 
59.48 
151.0 
60.39 
153.4 
61.33 
155,8 
62.37 
■ 153.4 
63.35 
160.9 
64.41 
163,6 
65.48 
166.3 
66.85 
169.8 
67.90 
172.5 
62.30 
158.2 
Sixteen, 
359 
inch, 
59.76 
151.8 
61.21 
155.5 
62.80 
159.5 
63.75 
161.9 
64.58 
154.0 
65.35 
168.0 
66.06 
167.8 
66.74 
169.5 
67.47 
171,4 
68.65 
174.4 
69.88 
177,4 
65.00 
165.1 
Seventeen, 
192 
inch. 
61.40 
156.0 
62.60 
159.0 
63.85 
162.2 
64.98 
165.0 
65.57 
166.5 
66.21 
168.2 
67.01 
170.2 
67.97 
172.6 
68.74 
174,6 
69.98 
177.4 
70.94 
180.2 
66.16 
168.0 
Eighteen, 
84 
inch, 
c. m., 
63.04 
160.1 
63.88 
j 162.3 
64.87 
164.8 
65.55 
166,5 
66.19 
188.1 
66.79 
169.8 
67.39 
171.2 
• 67.99 
172.7 
68.75 
174.6 
70.10 
178.1 
70.80 
179.8 
66.66 
j 169.3 No. 34.] 
THE GROWTH OF CHILDREN. 
Age at Last Birthday. 
Number 
of 
Observa- 
tions. 
Unit of 
Measure- 
ment. 
Values at the Following Percentile Grades. 
Average. 
1 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 95 
Per Cent.! Per Cent. 
Five, 
201 
inch, 
38.22 
39.26 
40.34 
40.95 
41.40 
41.84 
42.34 
42.88 
43.54 
44.38 
44.94 
41.74 
c. m., 
97.08 
99.72 
102.46 
104.01 
105.16 
106,27 
107,54 
108.91 
110,59 
112.72 
114.15 
106.0 
Six, 
342 
inch, 
41.09 
41.83 
42.56 
43.14 
43.57 
44.00 
44.57 
45.17 
45.87 
46.79 
47.62 
44.10 
c. m., 
104,37 
106.25 
108,10 
109.58 
110.67 
111,76 
113,21 
114.73 
116.51 
118.85 
120.35 
112,0 
Seven, . 
369 
inch, 
42.79 
43.83 
•44.65 
45.44 
45.84 : 
46.36 
46.87 
47.41 
47.96 
48.92 
49.70 
46 21 
c. m., 
108.69 
111.33 
113.41 
115.42 
116,44 
117.75 
119,06 
120.43 
121.83 
124,27 
126,25 
117.4 
Eight, . 
407 
inch, 
44.57 
45.45 
46.43 
47.18 
47.78 
48.34 
48.88 
49.46 
50.06 
50.98 
51.93 
48.16 
c. m., 
113.21 
115.44 
117,93 
119.83 
121.36 
122.78 
124,15 
125.62 
127.15 
129.49 
131.91 
122.3 
Nine, 
381 
inch, 
46.92 
47.44 
48.30 
49.04 
49.55 
50.07 
50.64 
51.25 
51.96 
53.09 
54.00 
50.09 
c. m., 
119.18 
120.50 
122.68 
124.56 
125.86 
127.18 
128.62 
130.17 
131.98 
134,85 
137,16 
127.2 
Ten, 
360 
inch, 
48.91 
49.39 
50.20 
51.02 
51.65 
52.24 
52.76 
53.44 
54.32 
55.50 
56.33 
52.21 
c. m., 
124.24 
125.45 
127,51 
129.59 
131.19 
132,69 
134.01 
135.74 
137.97 
140.97 
143,08 
132,6 
Eleven,. 
350 
inch, 
50.06 
50.76 
52.02 
52.68 
53.39 
54.14 
54.86 
55.62 
56.37 
57.26 
58.29 
54.01 
c. m., 
127.15 
128.93 
132,13 
133.80 
135.61 
137,51 
139.34 
141.27 
143,18 
145.44 
148.06 
137.2 
Twelve, 
373 
inch, 
51.48 
52.35 
53.54 
54.36 
55.07 
55.68 
56.37 
57.25 
58.43 
59.68 
60.71 
55.78 
c. m., 
130.76 
132,97 
135.99 
138.07 
139,88 
141.43 
143,18 
145,41 
148.41 
151,59 
154,20 
141.7 
Thirteen, 
391 
inch, 
53.32 
54.23 
55.69 
56.52 
57.26 
58.14 
58.95 
59.80 
60.93 
62.38 
63.65 
58.17 
c. m., 
135.43 
137.74 
141.45 
143.56 
145.44 
147.63 
149,73 
151,89 
154,76 
158.45 
161.67 
147.7 
Fourteen, 
386 
inch, 
54.44 
56.44 
58.11 
58.89 
59.80 
60.77 
61.87 
62.98 
64.18 
65.62 
67.31 
61.08 
c. m., 
138.28 
142,85 
147.60 
149,07 
151,89 
154,36 
157.15 
159,97 
163.02 
166,67 
170.97 
155.1 
Fifteen, 
342 
inch. 
57.02 
58.80 
60.08 
61.22 
62.33 
63.17 
64.14 
65.04 
65.96 
67.41 
68.42 
62.96 
c. m 
144.83 
149,45 
152.60 
155.50 
158,32 
160.45 
162.92 
165.20 
167,54 
171.22 
173,79 
159.9 
Sixteen, 
232 
inch, 
60.80 
61.93 
63.27 
64.34 
66.23 i 
66.03 
66.62 
67.22 
67.83 
69.16 
70.22 
65.58 
c. m., 
154,43 
157.30 
160,71 
163.42 
165,68 
167.72 
159,21 
170.74 
172.29 
175.67 
178.38 
166.5 
Seventeen, 
128 
inch, 
61.70 
62.64 
64.20 
65.11 
65.72 
66.39 
67.14 
68.08 
68.76 
70.03 
70.94 
66.29 
c. ra., 
156.72 
159.11 
163.07 
165.35 
166.93 
168,63 
170.54 
172,92 
174,65 
178,00 
180,19 
168,4 
Eighteen, 
65 
inch, 
63.07 
64.08 
65.08 
65.62 
66.18 
66.77 | 
67.36 
67.95 
68.86 
70,42 
70.95 
66.76 
c. m., 
160.20 
162,76 
165,30 
166.67 
168.10 
169.60 j 
171.09 
172.59 
174.90 
178.87 
180.21 
159.5 
Table No. 2. Calculated from Table 5 of Original Article. 
Heights of Boston School-boys of American Parentage, STATE BOARD OF HEALTH. 
[Pub. Doc, 
Number 
of 
_ Unit of 
I 
Values at the Following Percentile Grades. 
AGE AT LAST J5IRTHDAT. 
Observa- 
tions. 
merit. 
5 
Per Cent'. 
10 
Per Cent. 
30 
Per Cent. 
»o 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
93 
Per Cent. 
Average. 
Five, 
366 
inch, 
c. m., 
38.66 
98.2 
39.31 
99.8 
40.13 
101.9 
40.70 
103.4 
41.23 
104,7 
41.70 
105.9 
42.21 
107.2 
42.77 
108.6 
43.41 
110.3 
44.17 
112.2 
44.76 
113,7 
41.59 
105.5 
Six, 
503 
inch, 
c. m., 
40.58 
103.1 
41.41 
105.2 
42.31 
107,5 
42.88 
108.9 
43.40 
110,2 
43.90 
111.5 
44.33 
112.6 
44.74 
113,6 
45.30 
115.1 
46.22 
117.4 
47.05 
119.5 
43.74 
111.1 
Seven, . 
562 
inch, 
c. m., 
42.47 
107.9 
43.22 
109,8 
44.08 
112.0 
44.63 
113,4 
45.17 
114.7 
45.68 
116,0 
46.19 
117.3 
46.67 
118.5 
47.27 
120.1 
48.16 
122.3 
49.09 
124.7 
45.61 
115.8 
Eight, . 
588 
inch, 
c. p., 
44.77 
113.7 
45.38 
115.3 
46.24 
117.4 
46.88 
119,1 
47.36 
120.3 
47.80 
121,4 
48.26 
122,6 
48.73 
123.8 
49.38 
125,4 
50.37 
127.9 
51.09 
129,8 
47.72 
121.2 
Nine, 
556 
inch, 
c. m., 
1 46.51 
118.1 
47.18 
119,8 
48.03 
122.0 
48.60 
123.4 
49.14 
124.8 
49.61 
126.0 
50.11 
127.3 
50.72 
128-8 
51.48 
130.8 
52.46 
133.2 
53.12 
134.9 
49.53 
125,2 
Ten, 
571 
inch, 
c. m., 
47.93 
121,7 
48.93 
124.3 
49.75 
126.4 
50.40 
128.0 
50.99 
129,5 
51.62 
131.1 
52.22 
132.6 
52.77 
134.0 
53.56 
136,0 
54.66 
138.8 
55.73 
141,5 
51.57 
131.1 
Eleven,. 
548 
inch, 
c. m., 
49.41 
125.5 
50.34 
127,9 
51.29 
130.3 
51.98 
132.0 
52.58 
133,6 
5317 
135.0 
53.76 
136,5 
54.42 
138,2 
55.16 
140.1 
56.01 
142.3 
56.95 
144,6 
53.10 
134.9 
Twelve, 
497 
inch, 
c. in., 
51.02 
129.6 
51.76 
131.5 
52.80 
134.1 
53.58 
136,1 
54.27 
137,8 
54.89 
139,4 
55.51 
141,0 
56.14 
142,6 
56.85 
144.4 
58.08 
147,5 
59.57 
151.3 
54.82 
139.3 
Thirteen, 
463 
inch, 
c. m., 
52.64 
133.4 
53.45 
135.8 
54.59 
138.7 
55.36 
140,6 
55.99 
142,2 
56.58 
143.7 
57.26 
145.4 
58.17 
147,7 
59.06 
150.0 
60.37 
153.3 
61.74 
156.8 
56.70 
144.0 
Fourteen, 
334 
inch, 
c. m., 
54.44 
138.3 
55.52 
141.0 
56.89 
144.5 
57.62 
146.3 
58.25 
147.9 
58.81 
149.4 
59.56 
151.3 
60.38 
153.4 
61.31 
155,7 
62.73 
159.3 
63.94 
162.4 
58.88 
149.5 
Fifteen, 
155 
inch, 
c. m., 
56.24 
142,8 
57.28 
145,5 
58.75 
149.2 
59.62 
151,4 
60.33 
153.2 
60.98 
154.9 
61.83 
157,0 
62.96 
159.9 
64.00 
162,6 
65.37 
166.0 
66.07 
167.8 
61.15 
155.3 
Sixteen, 
61 
inch, 
c. m., 
58.50 
148,6 
59.35 
150,7 
61.40 
156.0 
63.19 
160.5 
63.70 
161,8 
64.42 
163,6 
65.29 
165,8 
65.97 
167.6 
66.83 
169.7 
67.70 
172.0 
68.45 
173.9 
64.09 
162.8 
Seventeen, 
26 ) 
inch, 
60.50 
63.10 
63.64 
65.06 
65.68 
66.75 j 
67.52 
68.17 
68.95 
69.97 
70.70 
66.20 
Eighteen, 
5| 
c. m., 
153.7 
160.3 
161,6 
165,2 
166.8 
169.5 i 
1 
171.4 
173.1 
175.1 
177.2 
179.6 
168.2 
Table No. 3. Calculated from Table 6 of Original Article. 
Heights of Boston School-boys of Irish Parentage. No. 34.] 
THE GROWTH OF CHILDREN. 
Age at Last Birthday. 
Number 
of 
Observa- 
tions. 
Unit of 
Weights. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
§0 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Five, . 
848 
pound, 
34.36 
35.36 
37.36 
38.75 
39.85 
40.96 
42.08 
43.54 
45.01 
47.31 
49.35 
41.09 
kilogram, 
15.59 
16.05 
16.96 
17.58 
18,07 
18.59 
19,10 
19.76 
20.42 
21.47 
22.39 
18.64 
Six, . 
1,258 
pound, 
38.01 
39.06 
41.07 
42.64 
43.83 
45.02 
46.27 
47.75 
49.24 
51.75 
53.55 
45.17 
kilogram, 
17.24 
17.72 
, 18.63 
19,35 
19.89 
20.43 
20,99 
21.67 
22.34 
23,47 
24.29 
20.49 
Seven, 
1,419 
pound, 
40.55 
42.54 
44.49 
46.30 
47.60 
48.90 
50.27 
51.97 
53.67 
56.68 
59.00 
49.07 
kilogram, 
18.40 
19.30 
20,18 
21,01 
21.60 
22.19 
22.80 
23.57 
24.34 
25,71 
26.76 
22.26 
Eight, 
1,481 
pound, 
44.37 
46.59 
48.95 
50.78 
52.17 
53.57 
55.23 
57.01 
59.25 
62.15 
64.94 
53.92 
kilogram, 
20.13 
21,14 
22,21 
23.03 
23,67 
24.30 
25,05 
25.86 
25.87 
28,20 
29.46 
24.46 
Nine, . 
1,437 
pound, 
48.89 
50.97 
53.74 
65.55 
57.26 
58.95 
60.62 
62.41 
64.70 
68.06 
70.95 
59.23 
kilogram, 
22.18 
23.12 
24,38 
25,20 
25.98 
26,74 
27.50 
28.32 
29,35 
30.88 
32.19 
26,87 
Ten, . 
1,363 
pound, 
52.59 
55.07 
58.47 
60.87 
63.10 
65.18 
67.23 
69,24 
72.05 
75.98 
79.13 
65.30 
kilogram, 
23.86 
24.98 
26,52 
27.61 
28,63 
29.57 
30.50 
31.41 
32,68 
34,47 
35,90 
29,62 
Eleven, 
1,293 
pound, 
56.60 
59.45 
63.09 
65.66 
67.74 
69.74 
71.92 
74.16 
77.12 
81.63 
85.95 
70.18 
kilogram, 
25.67 
26.36 
28.62 
29.79 
30,74 
31,64 
32.63 
33.64 
34.99 
37,04 
39,00 j 
31.84 
Twelve, 
1,253 
pound, 
61.40 
64.29 
68.29 
71.17 
73.46 
75.7,4 
78.05 
81.24 
84.96 
91.10 
96.66 1 
76.92 
kilogram, 
27.85 
29.16 
30,98 
32.29 
33,33 
34,37 
35.41 
36.86 
38.55 
41.33 
43.85 
34,89 
Thirteen, . 
1,160 
pound, 
67.23 
70.75 
74.53 
77.47 
80.15 
82.90 
85.97 
89.51 
94.47 
102.39 
108.80 
84.84 
kilogram, 
30.50 
32,10 
33.81 
35,15 
36.37 
37.62 
39,01 
40,61 
42.85 
46,46 
49.36 
38,49 
Fourteen, . 
90S 
pound, 
72.16 
76.38 
81.92 
85.72 
89.47 
93.03 
96.86 
101.74 
107.40 
116.99 
124.83 
94.91 
kilogram, 
32,74 
34.65 
37.17 
38.90 
40.59 
42,20 
43,94 
46.16 
48.73 
53.07 
56,63 
42,95 
Fifteen, 
636 
pound, 
80.70 
85.41 
91.78 
97.05 
101.74 
106.00 
110.72 
115.38 
121.76 
131.08 
139.40 
107.10 
kilogram, 
36,62 
38.76 
41,63 
44,03 
46.16 
48,09 
50.23 
52,34 
55.23 
59.47 
63.24 
48.59 
Sixteen, 
359 
pound, 
92.95 
98.30 
108.40 
112.89 
116.77 
121.38 
124.51 
128.23 
133.70 
142.03 
148.00 
121.01 
kilogram, 
42.17 
44.60 
49,18 
51,22 
52.98 
55,06 
56,48 
58,17 
60,66 
64,44 
67.15 
54,90 
Seventeen, 
192 
pound, 
101.20 
109.20 
114.76 
118.84 
122.38 
126.57 
131.80 
136.77 
140.78 
150.40 
156.40 
127.49 
kilogram, 
45.91 
49.54 
52.06 
53,92 
55.52 
57,42 
59.79 
62,05 
63.87 
68.23 
70.95 
57,84 
Eighteen, . 
84 
pound, 
106.80 
115.92 
121.87 
124.98 
128.04 
131.71 
135.47 
138.36 
142.01 
147.20 
157.20 
132.55 
kilogram, 
48.45 
52.60 
55,28 
56.69 
58.09 
59,75 
61.46 
62.77 
64.43 
66.79 
71,32 
60.13 
* 
Table No. 4. Calculated from Table 7 of Original Article. 
Weights of Boston School-boys irrespective of Nationality. STATE BOARD OF HEALTH. 
[Pub. Doc. 
Number 
of 
Unit of 
Values at the Following Peecentile Grades. 
Average. 
Age at Last Birthday. 
Observa- 
tions. 
Weights. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
GO 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
OO 
Per Cent. 
1 93 
Per Cent. 
Five, . 
201 
pound, 
kilogram, 
34.19 
15,51 
35.13 
15.94 
37.00 
16.79 
38.54 
17.48 
39.70 
18.01 
40.87 
18,54 
42.05 
19,08 
43.59 
19.78 
45.14 
20.48 
47.87 
21.72 
49.98 
22,67 
41.20 
18.71 
Six, . 
342 
pound, 
kilogram, 
38.01 
17.24 
38.98 
17.68 
40.94 
18.58 
42.55 
19.31 
43.76 
19,85 
44.97 
20,40 
46.24 
20.98 
47.85 
21.72 
49.46 
22.44 
52.40 
23.77 
54.54 
24.73 
45.14 
29.48 
Seven, 
369 
pound, 
kilogram, 
40.37 
18,32 
42.45 
19,26 
44.56 
20.21 
46.46 
21.08 
47.92 
21.75 
49.39 
22,41 
50.91 
23.09 
52.48 
23.81 
54.10 
24,54 
57.24 
25,97 
59.81 
27.13 
49.47 
22.44 
Eight, 
407 
pound, 
kilogram, 
45126 
20.54 
47.00 
21.33 
49.43 
22.43 
51.13 
23.19 
52.61 
23.87 
54.10 
24.54 
55.76 
25.29 
57.42 
26.05 
59.77 
27.11 
62.83 
28,51 
65.15 
29,56 
54.43 
24,70 
Nine,. 
381 
pound, 
kilogram, 
48.80 
22.14 
51.07 
23,16 
54.11 
24.54 
55.94 
25,38 
57.78 
26,21 
59.41 
26.95 
61.01 
27.67 
62.57 
28.52 
65.11 
29.54 
69.82 
31,67 
73.41 
33.31 
59.97 
26.58 
Ten, . 
360 
pound, 
kilogram, 
54.00 
24,49 
56.25 
25.51 
59.61 
27.04 
62.64 
28.42 
64.56 
29.28 
66.46 
30.15 
68.31 
30.99 
70 .>24 
31.87 
73.12 
33.17 
76.86 
34.87 
80.29 
36.43 
66.62 
30,22 
Eleven, 
350 
pound, 
kilogram, 
58.35 
26,47 
62.18 
28.21 
65.36 
29.65 
67.51 
30.63 
69.41 
31,49 
71.52 
32.45 
73.75 
33.48 
76.14 
34.54 
79.45 
36,04 
84.90 
38,52 
89.17 
40,46 
72.39 
' 32,83 
Twelve, 
373 
pound, 
kilogram, 
62.38 
28,30 
65.16 
29.56 
69.95 
31.73 
72.64 
32.96 
75.32 
34.18 
78.04 
35.41 
81.22 
36.85 
84.34 
38.26 
88.90 
40.34 
95.62 
43,38 
102.24 
45,39 
79.82 
36,21 
Thirteen, . 
391 
pound, 
kilogram, 
69.80 
31.66 
72.94 
33.10 
76.93 
34.90 
79.79 
36.20 
82.45 
37,41 
85.71 
38.89 
89.16 
40.45 
93.83 
42.57 
99.78 
45.26 
107.58 
48.81 
114.23 
51,82 
88.26 
40,04 
Fourteen, . 
386 
pound, 
kilogram, 
74.91 
33.98 
78.74 
35.73 
84.14 
38.17 
89.04 
40,40 
93.22 
42,29 
97.44 
44.21 
101.73 
46,15 
106.83 
48.47 
114.17 
51.80 
124.16 
56.32 
131.85 
59.82 
99.28 
45.03 
Fifteen, 
342 
pound, 
kilogram, 
81.24 
36.86 
87.20 
39.57 
95.35 
43.26 
101.50 
45,05 
105.85 
48.03 
110.84 
50.29 
114.58 
51,98 
119.57 
54.25 
126.76 
57,50 
135.93 
61.67 
141.96 
64.41 
110.84 
50.26 
Sixteen, 
232 
pound, 
kilogram, 
96.30 
43.69 
101.28 
45.35 
110.08 
49.95 
114.84 
52.10 
119.29 
54,12 
123.33 
55.95 
126.23 
57.26 
130.76 
59.32 
136.65 
61.99 
145.02 
65.80 
151.60 
68.77 
123.67 
56,09 
Seventeen, 
-128 
pound, 
kilogram, 
98.80 
44.82 
110.36 
50.07 
115.53 
52,42 
119.54 
54.23 
123.29 
55.93 
127.60 
57,89 
133.40 
60.52 
137.57 
62.42 
140.85 
63.91 
150.13 
68.11 
154.60 
70,13 
128.72 
58.40 
Eighteen, . 
65 
pound, 
114.16 
116.80 
122.00 
125.25 
128.00 
1.31.20 
135.20 
137.80 
142.00 
152.00 
160.80 
132.71 
kilogram, J 
51.79 
52.99 
55.35 
56.72 
58,07 
59.52 
61.34 
62.52 
64.43 
68,96 
72,96 
60,20 
Table No. 5. Calculated from Table 8 of Original Article. 
Weights of Boston School-boys of American Parentage. No. 34.] 
THE GROWTH OF CHILDREN. 
Age at Last Birthday. 
Number 
of 
Observa- 
tions. 
Unit of 
Weights. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
TO 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
j Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
SO 
Per Cent. 
90 
Per Cent. 
03 
Per Cent. 
360 
pound, 
34.66 
35.72 
37.83 
39.04 
40.17 
41.29 
42.51 
43.89 
46.28 
47.70 
49.48 
41.33 
kilogram. 
15.72 
16.21 
17,17 
17.71 
18,23 
18,73 
19.29 
19,91 
20.55 
21,65 
22,45 
18.75 
Six, 
503 
pound, 
38.05 
39.16 
41.40 
42.86 
44.03 
45.20 
46.41 
47.69 
48.98 
51.00 
53.33 
45.25 
kilogram, 
17.26 
17.76 
1.8.78 
19.45 
19.97 
20,51 
21.08 
21.64 
22.22 
23.13 
24.19 
20.52 
562 
pound, 
41.24 
42.77 
44.70 
46.40 
47.61 
48.82 
50.04 
51.71 
53.39 
56.17 
57.87 
48.90 
kilogram, 
18.71 
19,41 
20,28 
21.05 
21.61 
22.15 
22.70 
23,45 
24.22 
25.48 
26.25 
22.19 
588 
pound, 
45.32 
47.08 
49.63 
51.13 
. 52.45 
53.78 
55.42 
57.14 
59.29 
61.88 
64.73 
54.12 
kilogram, 
20.57 
21,37 
22,52 
23,19 
23.79 
24,39 
25,14 
25,92 
26,89 
28.07 
29.36 
24.55 
556 
pound, 
48.55 
50.79 
53.44 
55.38 
57.13 
58.87 
60.61 
62.43 
64.54 
67.55 
70.04 
68.92 
kilogram, 
22.03 
23.04 
24.24 
25.12 
25.92 
26,70 
27.50 
23,33 
29.27 
30.65 
31.78 
23,73 
Ten, 
571 
pound, 
52.41 
54.83 
57.96 
60.42 
62.78 
64.95 
67.07 
69.12 
71.80 
75.47 
77.95 
64.99 
kilogram, 
23.78 
24.87 
25.30 
27.41 
28,48 
20.46 
30.43 
31.35 
32,57 
34,24 
35.37 
29.48 
548 
pound, 
56.37 
59.32 
62.84 
65.08 
67.25 
69.38 
71.55 
73.74 
76.62 
80.54 
84.65 
69.60 
kilogram, 
25.57 
25,91 
28.51 
29.53 
30.51 
31,47 
32.45 
33,46 
34.76 
36.54 
38.40 
31.56 
497 
pound, 
60.07 
63.91 
67.90 
70.70 
72.95 
75.18 
77.39 
80.02 
83.33 
89.01 
93.45 
75.70 
kilogram, 
27,25 
28,99 
30,71 
32.08 
33.10 
34.11 
35,12 
35.31 
37.81 
40,38 
42,39 
34.34 
463 
pound, 
66.66 
70.16 
73.47 
76.19 
78.85 
81.61 
84.65 
87.80 
91.69 
98.70 
102.36 
82.84 
kilogram, 
30.24 
31.83 
33.33 
34.57 
35,78 
37,03 
38.40 
39.84 
41,59 
44,78 
46.44 
37,58 
Fourteen, 
334 
pound, 
71.41 
74.88 
80.54 
84.02 
87.03 
90.28 
93.39 
97.25 
102.20 
108.49 
115.53 
91.19 
kilogram, 
32.40 
33.97 
36,54 
38.12 
39.49 
40,96 
42.37 
44,12 
46,37 
49,22 
52,42 
41.36 
155 
pound, 
80.69 
84.44 
89.00 
92.30 
95.65 
99.69 
104.29 
108.71 
114.00 
121.25 
125.10 
101.21 
kilogram, 
36.61 
38,31 
40.38 
41.88 
43.39 
45.22 
47.31 
49.32 
51.72 
55.00 
56.76 
45.90 
61 
pound, 
84.00 
91.47 
97.36 
109.07 
112.40 
115.43 
119.28 
123.80 
128.24 
133 .12 
137.80 
112.88 
kilogram, 
38.11 
41.49 
44.17 
49.48 
51.00 
52.38 
54.12 
56.16 
58,18 
60.39 
62,52 
51.19 
26 ) 
pound, 
102.67 
104.80 
111.20 
115.20 
121.20 
129.33 
132.00 
137.40 
142.80 
145.90 
159.60 
127.40 
Eighteen, . ... 
5 1 
kilogram, 
46.58 
47.54 
50.45 
52.27 
54.98 
58,67 
60.16 
62.34 
64.79 
63.20 
72,41 
57,80 
Table No. 6. Calculated from Table 9 of Original Article. 
Weights of Boston School-boys of Irish Parentage. STATE BOARD OF HEALTH. 
[Pub. Doc. 
Number 
of 
Unit of 
Measure- 
ment. 
Values at the Following Percentile 
Grades. 
Age at Last Birthday. 
Observa- 
tions. 
5 1 10 
Per Cent.1, Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
GO 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
»o 
Per Cent. 
95 
Per Cent. 
Average. 
Five, 
605 
inch, 
c. m., 
38.27 
97.2 
39.08 
99.3 
39.90 
101.3 
40.45 
102.7 
40.95 
104.0 
41.43 
105.2 
41.90 
106.4 
42.41 
107.7 
42.94 
110.1 
43.74 
111.1 
44.58 
113,2 
41.29 
104.9 
Six, 
987 
inch, 
c. m., 
40.30 
102,4 
41.10 
104.4 
41.91 
106.5 
42.45 
107.8 
42.95 
109.1 
43.40 
110,2 
43.85 
111.4 
44.41 
112.8 
45.03 
114.4 
45.90 
116.6 
46.71 
118.6 
43.35 
110.1 
Seven, . 
1,199 
inch, 
c. m., 
42.41 
107.7 
43.12 
109.5 
43.95 
111.6 
44.70 
113.5 
45.14 
114.7 
45.63 
115,9 
46.14 
117.2 
46.73 
118.7 
47.37 
120,3 
48.14 
122.3 
49.05 
124,6 
45.52 
115,6 
Eight, . 
1,299 
inch, 
c. m., 
44.08 
112.0 
44.91 
114,1 
45.94 
116,7 
46.53 
118.2 
47.09 
119,6 
47.65 
121.0 
48.23 
122,5 
48.84 
124.1 
49.66 
125.9 
50.56 
128.4 
51.37 
130.5 
47.58 
120,9 
Nidq, 
1,149 
inch, 
c. ra., 
45.81 
116.4 
46.56 
118.3 
47.67 
121,1 
48.41 
123,0 
49.01 
124.5 
49.64 
125.8 
50.08 
127.2 
50.65 
128.0 
51.32 
130.4 
52.33' 
132.9 
53.15 
135,0 
49.37 
125.4 
Ten, 
1,089 
inch, 
c. m., 
47.49 
120.6 
48.37 
122.9 
49.49 
125.7 
50.26 
127.7 
50.88 
129,2 
51.46 
130.7 
52.04 
132.2 
52.65 
133.7 
53.41 
135.7 
54.58 
138.6 
55.66 
141,4 
51.34 
130,4 
Eleven, . 
936 
inch, 
c. m., 
49.33 
125.3 
50.27 
127.7 
51.35 
130,4 
52.14 
132,4 
52.73 
133.9 
53.41 
135.7 
54.16 
137,6 
54.89 
139,4 
55.76 
141,6 
57.05 
144,9 
57.96 
147.2 
53.42 
135.7 
Twelve, 
935 
inch, 
c. in., 
51.25 
130.2 
52.24 
132.7 
53.45 
135.8 
54.33 
138.0 
55.15 
140.1 
55.88 
141.9 
56.59 
143.7 
57.38 
145.7 
58.39 
148.3 
59.73 
151.7 
60.81 
154.5 
55.88 
141.9 
Thirteen, 
830 
inch, 
c. 111., 
53.61 
136.2 
54.50 
138.4 
55.75 
141.6 
56.80 
144,3 
57.61 
146.3 
58.40 
148.3 
59.19 
150,3 
59.91 
152.2 
60.75 
154.3 
61.79 
156.9 
62.80 
159.5 
58.16 
147.7 
Fourteen, 
675 
inch, 
c. m., 
55.87 
141.9 
56.98 
144,7 
58.11 
147.6 
58.90 
149.6 
59.59 
151.4 
60.20 
152.9 
60.71 
154.2 
61.28 
155.7 
61.94 
157.3 
62.99 
180.0 
64.05 
152,7 
59.94 
152.3 
Fifteen, 
459 
inch, 
c. m., 
57.39 
145.8 
58.29 
148.1 
59.33 
150.7 
60.10 
152,7 
60.67 
154.1 
61.21 
155.5 
61.73 
156,8 
62.32 
153.3 
63.15 
160.4 
64.15 
162.9 
65.00 
165.1 
61.10 
155.2 
Sixteen, 
353 
inch, 
c. m., 
57.82 
146.9 
58.64 
148.9 
59.72 
151.7 
60.49 
153.6 
61.16 
155.3 
61.78 
156.9 
62.37 
158.4 
62.95 
159.9 
63.68 
161.7 
64.77 
164.5 
65.59 
165,6 
61.59 
156.4 
Seventeen, 
233 
inch, 
c. m., 
58.22 
147.9 
59.08 
150,1 
59.95 
152,3 
60.88 
154,6 
61.58 
156,4 
62.18 
157.9 
62.68 
159.2 
63.21 
160.6 
63.83 
162.1 
64.88 
164,8 
65.85 
167.3 
61.92 
157,2 
Eighteen, 
155 
inch, 
c. m., 
58.67 
149.0 
59.31 
150.6 
60.12 
152,7 
60.77 
154.4 
61.33 
155.8 
61.85 
157.1 
62.39 
158.5 
62.95 
159,9 
64.14 
162.9 
64.88 
164.8 
65.87 
167,3 
61.95 
157.3 
Table No. 7. Calculated erom Table 10 of Original Article. 
Heights of Boston School-girls irrespective of Nationality. No. 34.] 
THE GROWTH OF CHILDREN. 
Age at Last Birthday. 
Number 
of 
Observa- 
tions. 
Unit of 
Measure- 
ment. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
30 
Per Cent. 
60 
Per Cent. 
VO 
Per Cent. 
SO 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Five, 
127 
inch, 
38.55 
39.28 
40.14 
40.67 
41.17 
41.60 
42.06 
42.66 
43.31 
44.04 
44.94 
41.47 
C. Ill., 
■ 97.9 
99,8 
102,0 
103,3 
104.6 
105.7 
106,8 
108.4 
110.3 
111.9 
114.2 
105,3 
Six, 
236 
inch, 
40.57 
41.27 
42.13 
42.62 
43.11 
43.59 
44.10 
44.75 
45.43 
46.39 
47.36 
43.66 
c. m., 
103.1 
104,8 
107.0 
108.3 
103.5 
110.7 
112.0 
113.7 
115.4 
117,8 
120,3 
110.9 
Seven, . 
346 
inch, 
42.71 
43.43 
44.35 
45.01 
45.53 
46.05 
46.57 
47.12 
47.78 
48.71 
49.51 
46.94 
c. m., 
108.5 
110,3 
112.7 
114,3 
115.7 
117.0 
118.3 
119.7 
121.4 
123.7 
125.8 
116.7 
Eight, . 
338 
inch, 
44.33 
45.25 
46.29 
47.01 
47.60 
48.21 
48.86 
49.50 
50.18 
51.05 
51.82 
48.07 
c. m., 
112.6 
114,9 
117,6 
119.4 
120.9 
122.4 
124,1 
125.7 
127,5 
129.7 
131.6 
122.1 
Niue, 
323 
inch, 
46.21 
46.89 
48.08 
48.61 
49.16 
49.70 
50.27 
50.86 
51.64 
52.81 
53.69 
49.61 
c. m., 
117.4 
119.1 
122.1 
123.5 
124.9 
126.2 
127.7 
129,2 
131.2 
134.1 
135,4 
126,0 
Ten, * . 
336 
inch, 
47.91 
48.82 
49.87 
50.70 
51.32 
51.90 
52.50 
53.14 
53.93 
54.98 
56.32 
51.78 
c. m., 
121,7 
124.0 
126.7 
128.8 
130,3 
131,8 
133,3 
135,0 
137,0 
139,6 
143.0 
131.5 
Eleven, . 
290 
inch, 
49.69 
50.48 
51.52 
52.37 
53.11 
53.92 
54.63 
55.42 
56*. 36 
57.52 
58.37 
53.79 
c. m., 
126.2 
128.2 
130,9 
133.0 
134,9 
137.0 
138,8 
140,8 
143,1 
146,1 
148.3 
136,6 
Twelve, 
309 
inch, 
52.18 
53.15 
54.10 
55.12 
55.91 
56.61 
57.34 
58.20 
59.31 
60.51 
61.62 
57.16 
c. m., 
132.5 
135,0 
137,4 
140,0 
142,0 
143,8 
145.6 
147.8 
150.6 
153.7 
156.5 
145.2 
Thirteen, 
307 
inch, 
54.07 
54.88 
56.41 
57.44 
58.25 
59.10 
59.75 
60.46 
61.27 
62.41 
63.35 
58.75 
c. m., 
137.3 
139.4 
143.3 
145.9 
147,9 
150.1 
151.8 
153,5 
155,6 
158.5 
160.9 
149.2 
Fourteen, 
290 
inch, 
56.69 
57.71 
58.63 
69.40 
60.03 
60.47 
60.91 
61.54 
62.26 
63.27 
64.27 
60.32 
c. m., 
144.0 
146.6 
149,1 
150,9 
152,5 
153,6 
154.7 
156.3 
158.1 
160.7 
103,2 
153.2 
Fifteen, 
255 
inch, 
58.11 
58.91 
59.75 
60.39 
60.95 
61.43 
61.89 
62.53 
63.30 
64.36 
65.17 
61.39 
c. m., 
147.6 
149.6 
151,8 
153,4 
154.8 
156.0 
157.2 
158,8 
160.8 
163,5 
165.5 
155.9 
Sixteen, 
238 
inch, 
57.99 
58.66 
59.70 
60.55 
61.31 
62.02 
62.45 
63.08 
63.80 
64.86 
65.65 
61.72 
c. m., 
147.3 
149.0 
151,6 
153.8 
155.7 
157.5 
158,6 
160.2 
162,0 
164.7 
166.7 
156.7 
Seventeen, 
168 
inch, 
58.17 
59.11 
60.14 
61.06 
61.76 
62.32 
62.82 
63.34 
63.88 
64.88 
65.82 
61.99 
c. m., 
147.7 
150.1 
152,8 
155,1 
156,9 
158.3 
159.6 
160.9 
162,3 
164,8 
167.2 
157.4 
Eighteen, 
118 
inch, 
58.58 
59.38 
60.33 
61.02 
61.47 
61.92 
02.47 
63.08 
64.24 
64.90 
65.68 
62.01 
c. in., 
148.8 
150.8 
153.2 
155.0 
156.1 
157.3 
158.7 
160,2 
163.2 
164.9 
166,8 
157,5 
Table No. B.—Calculated from Table 11 of Original Article. 
Heights of Boston School-girls of American Parentage. STATE BOARD OF HEALTH. 
[Pub. Doc 
Age at Last Birthday. 
Number 
of 
Observa- 
tions. 
Unit of 
Measure- 
ment. 
Values at the Following Percentile Grades. 
| Average, 
5 
Per Cent. 
JO 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Five, 
236 
inch, 
38.21 
39.07 
40.06 
40.49 
40.92 
41.34 
41.76 
42.20 
42.68 
43.32 
43.83 
41.18 
c. m., 
97,0 
99,2 
101.7 
102.8 
103,9 
105,0 
106.1 
107,2 
108.4 
110,0 
111.3 
104.6 
Six, 
395 
inch, 
40.23 
41.08 
41.76 
42.36 
42.92 
43.39 i 
43.85 
44.42 
45.06 
45.80 
46.48 
43.29 
1 
c. m., 
102,2 
104.3 
106.1 
107,6 
109.0 
110.2 
111.4 
112.8 
114,4 
116.3 
118.1 
109,9 
Seven, . 
426 
inch, 
42.54 
43.23 
44.00 
44.54 
45.07 
45.52 
45.97 
46.63 
47.29 
47.94 
48.99 
45.45 
c. m., 
108.0 
109.8 
111,8 
113.1 
114.5 
115,6 
116.8 
118.4 
120.1 
121.8 
124.4 
115.4 
Eight, . 
4S6 
inch, 
43.86 
44.65 
45.71 
46.37 
46.90 
47.46 
48.03 
48.65 
49.36 
50.31 
50.96 
47.39 
c. m., 
111.4 
113.4 
116.1 
117.8 
119.1 
120.5 
122,0 
123.6 
125.4 
127,8 
129.4 
120.4 
Nine, 
4X6 
inch, 
45.58 
46.43 
47.53 
48.36 
49.10 
49.60 
50.09 
50.59 
51.15 
52.16 
52.90 
49.27 
c. m., 
115,8 
117.S 
120.7 
122.8 
124,7 
126.0 
127.2 
128.5 
129.9 
132,5 
134,4 
125.2 
Ten, 
379 
inch, 
47.49 
48.52 
49.68 
50.34 
50.86 
51.37 
51.87 
52.42 
52.97 
54.21 
55.00 
51.20 
c. m., 
120,6 
123,2 
126.2 
127.9 
129.2 
130.5 
131.7 
133.1 
134,5 
137,7 
139.7 
130.1 
Eleven, . 
340 
inch, 
49.50 
50.37 
51.35 
52.03 
52.55 
53.08 
53.73 
54.38 
55.03 
56.18 
67.47 
53.13 
c. m., 
125,7 
127,9 
130.4 
132.2 
133.5 
134.8 
136.5 
138.1 
139,8 
142,7 
146,0 
134.9 
Twelve, 
307 
inch, 
51.12 
51.93 
53.19 
53.98 
54.76 
55.49 
56.18 
56.92 
57.84 
59.33 
60.47 
65.41 
c. in., 
129.8 
131,9 
135.1 
137.1 
139.1 
140.9 
142.7 
144,6 
146.9 
150.7 
153.6 
140,8 
Thirteen, 
278 
inch, 
53.39 
54.37 
55.49 
56.33 
57.05 
57.75 
58.49 
59.30 
60.18 
61.19 
62.02 
57.64 
c. m., 
135,6 
138.1 
140.9 
143.1 
144.9 
146.7 
148,6 
150,6 
152,9 
155.4 
157.5 
146,3 
Fourteen, 
192 
inch, 
55.66 
56.80 
57.72 
58.47 
59.21 
60.03 
60.56 
61.11 
61.75 
62.74 
63.54 
59.67 
c. m., 
141.4 
144.3 
146.6 
148.5 
150.4 
152.5 
153.8 
155,2 
156,8 
159,4 
161,4 
151.5 
Fifteen, 
95 
inch, 
56.23 
57.50 
58.70 
59.50 
60.16 
60.66 
61.15 
61.62 
62.29 
63.64 
64.73 
60.47 
c. m., 
142.8 
145,0 
149.1 
151.1 
152.8 
154.1 
155.3 
156,5 
158,2 
161.6 
164.4 
153,5 
Sixteen, 
49 
inch, 
57.20 
58.90 
60.06 
60.47 
60.88 
61.32 
61.76 
62.26 
62.80 
64.03 
64.83 
61.05 
c. m., 
145.3 
149,6 
152.5 
153.6 
154.6 
155.7 
156.9 
158.1 
159.5 
162.6 
164.7 
155.1 
Seventeen, 
18 j 
inch, 
58.20 
59.10 
59.70 
60.60 
61.32 
61.80 
62,35 
62.95 
64.10 
65.60 
66.80 
62.00 
Eighteen, 
6j 
c. m., 
147.8 
150.1 
151.6 
153.9 
155,7 
157,0 
158.4 
159.9 
162,8 
166.6 
169.7 
157.5 
Table No. 9. Calculated from Table 12 of Original Article. 
Heights of Boston School-girls of Irish Parentage. No. 34.] 
THE GROWTH OF CHILDREN. 
Number 
Unit of 
Values at the Following Percentile Grades. 
Average. 
Age at 
Last Birthday. 
Observa- 
tions. 
Weights. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Five, . 
605 
pound, 
kilogram, 
32.45 
14.72 
34.31 
15.56 
35.82 
16.25 
37.34 
16.94 
38.59 
17.51 
39.63 
17.98 
40.67 
18.45 
41.72 
18.93 
43.44 
19,71 
45.43 
20,62 
47.88 
21.73 
39.66 
17.99 
Six, . 
9S7 
pound, 
kilogram, 
35.42 
16,07 
37.13 
16,85 
39.04 
17.71 
40.43 
18.22 
41.83 
18.98 
43.11 
19,55 
44.37 
20.13 
45.63 
20,71 
47.56 
21,58 
49.78 
22.58 
52.36 
23.75 
43.28 
19.63 
Seven, 
1,199 
pound, 
kilogram, 
39.04 
17.71 
40.64 
18.44 
42.87 
19,45 
44.37 
20.13 
45.88 
20,82 
47.30 
21.47 
48.71 
22.10 
50.19 
22,77 
52.45 
23.79 
55.36 
25.11 
57.56 
26.11 
47.46 
27,10 
Bight, 
1,299 
pound, 
kilogram, 
42.61 
19.34 
44.25 
20.07 
46.85 
21.26 
48.33 
21.93 
50.31 
22.82 
51.45 
23,33 
53.45 
24,24 
55.27 
25,07 
57.24 
25.97 
60.32 
27.37 
62.60 
28.40 
52.04 
23.44 
Nine, . 
1,149 
pound, 
kilogram, 
46.16 
20.94 
48.21 
21.88 
51.16 
23.20 
53.22 
24.14 
55.00 
24,95 
56.62 
25.68 
58.28 
26.44 
60.32 
27,37 
62.57 
28.39 
65.83 
29,87 
69.96 
31,74 
57.07 
25,91 
Ten, . 
1,089 
pound, 
kilogram, 
50.26 
22.80 
52.19 
23,68 
55.26 
25,07 
57.64 
26.15 
59.56 
27.01 
61.40 
27,85 
63.70 
28.90 
66.24 
30.05 
69.03 
31.31 
73.43 
33.32 
76.89 
34,88 
62.35 
28,29 
Eleven, 
936 
pound, 
kilogram, 
54.08 
23.90 
56.16 
25.47 
59.61 
27.04 
62.42 
28.32 
64.92 
29,45 
67.62 I 
30.62 
70.48 
31.88 
73.36 
33.28 
77.07 
34.97 
83.71 
37.98 
89.27 
40.50 
68.84 
31.23 
Twelve, 
935 
pound, 
kilogram, 
59.69 
27.07 
62.97 
28,57 
67.32 
30.55 
70.64 
32.05 
73.53 
33.36 
77.08 
34,98 
80.50 
36.53 
84.04 
38.13 
88.23 
40.03 
94.71 
41.21 
102.73 
46.61 
78.31 
35,53 
Thirteen, 
830 
pound, 
kilogram, 
65.75 
29.83 
70.37 
31.93 
75.16 
34,10 
79.33 
35.99 
83.92 
38.08 
88.02 
39.94 
91.98 
41.72 
96.46 
43,76 
102.12 
46.33 
108.47 
49.21 
115.42 
52.37 
88.65 
40,21 
Fourteen, 
675 
pound, 
kilogram, 
76.57 
34.74 
80.36 
36.46 
85.76 
38.91 
90.14 
40.89 
94.00 
42.64 
97.75 
44.35 
101.23 
45.92 
105.68 
47,95 
109.94 
49.88 
117.12 
53.14 
124.73 
56.58 
98.43 
44,65 
Fifteen, 
459 
pound, 
kilogram, 
83.39 
37.84 
88.80 
40.29 
• 95.43 
43.30 
99.59 
45.18 
102.49 
46.50 
105.11 
47.69 
108.43 
43.20 
112.39 
51,00 
117.64 
53,38 
124.14 
56.31 
132.22 
59.99 
106.08 
48.12 
Sixteen, 
353 
pound, 
kilogram, 
88.47 
40.14 
93.51 
42.42 
99.05 
44,93 
103.50 
46,96 
107.28 
48.68 
111.27 
50.48 
115.79 
52.54 
119.95 
54.42 
124.79 
56,61 
130.99 
59.43 
135.94 
61,68 
112.03 
50,81 
Seventeen, 
233 
pound, 
kilogram, 
93.20 
42,28 
97.75 
44,35 
104.32 
47.33 
107.57 
48,81 
110.02 
49.92 
112.76 
51.16 
117.20 
53.18 
122.75 
55.69 
127.54 
57.86 
135.88 
61.65 
141.15 
64,04 
115.53 
52.41 
Eighteen, 
155 
pound, 
kilogram, 
95.20 
43,19 
98.40 
44.64 
102.36 
46.44 
105.18 
47,72 
110.16 
49.98 
112.64 
51.11 
116.80 
52.99 
122.88 
55.75 
127.33 
57.77 
133.45 
60.54 
138.80 
62.97 
115.16 
52,24 
Table No. 10. Calculated from Table 13 of Original Article. 
Weights of Boston School-girls irrespective of Nationality. STATE BOARD OF HEALTH. 
[Pub. Doc. 
Number 
Unit of 
Valdes at the Following Percentile Grades. 
Average. 
Age at Last Birthday. 
Observa- 
tions. 
Weights. 
5 
Per Cent. 
IO 
Per Cent. 
20 
Per Cent. 
ao 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Five, . 
127 
pound, 
kilogram, 
32.52 
14.76 
34.34 
15.57 
35.92 
16,30 
37.51 
17.02 
38.64 
17.53 
39.56 
17.94 
40.49 
18.37 
41.41 
18.79 
42.97 
19,50 
45.64 
20.71 
50.40 
22.86 
39.82 
18.06 
Six, . 
236 
pound, 
kilogram, 
35.69 
16.19 
37.37 
16.96 
39.22 
17.79 
40.72 
18.48 
42.18 
19.14 
43.44 
19.71 
44.70 
20,28 
45.96 
20.86 
48.34 
21.93 
51.48 
23.35 
53.84 
24.42 
43.81 
19.87 
Seven, 
346 
pound, 
kilogram, 
39.43 
17,89 
41.16 
18.67 
43.25 
19,62 
44.90 
20.37 
46.43 
21.07 
47.74 
21.67 
49.04 
22,25 
50.61 
22.96 
52.92 
24,01 
56.23 
25.50 
58.72 
26,64 
48.02 
21,78 
Eight, 
338 
pound, 
kilogram, 
42.85 
19.45 
44.68 
20,27 
47.27 
21.45 
49.26 
22.35 
50.99 
23.13 
52.56 
23,84 
54.15 
24.56 
56.01 
25.40 
57.80 
26,25 
61.47 
27.88 
65.46 
29.95 
52.93 
24,01 
Nine,. 
323 
pound, 
kilogram, 
46.60 
21,14 
48.51 
22,01 
51.14 
23.19 
53.01 
24,05 
54.81 
24,86 
56.53 
25,74 
58.38 
26,48 
60.97 
27,66 
63.65 
28.87 
67.34 
30,55 
72.27 
32.79 
57.52 
26.10 
Ten, . 
336 
pound, 
kilogram, 
50.36 
22,84 
52.53 
23.83 
55.68 
25.26 
58.18 
26,39 
60.39 
27.40 
62.65 
28.42 
65,10 
29-54 
67.84 
30,78 
71.53 
32.45 
77.37 
35.11 
86.60 
39.29 
64.09 
29.07 
Eleven, 
290 
pound, 
kilogram, 
54.25 
24,60 
56.67 
25.70 
60.05 
27.24 
63.06 
28,61 
65.43 
29,69 
68.75 
31.19 
72.11 
32.72 
75.41 
34.22 
79.40 
36,02 
86.73 
39.35 
92.75 
42,08 
70.26 
31.87 
Twelve, 
309 
pound, 
kilogram, 
62.84 
28.51 
65.79 
29.85 
69.61 
31.58 
72.77 
33,02 
76.48 
34.70 
79.90 
36,25 
83.07 
37,69 
86.62 
39,30 
90.40 
41,01 
97.70 
44.33 
106.10 
43.14 
81.35 
36.90 
Thirteen, 
307 
pound, 
kilogram, 
66.43 
30.14 
71.04 
32.23 
77.66 
35.24 
81.88 
37,15 
86.75 
39.36 
90.88 
41.23 
95.60 
43,37 
100.53 
45.61 
104.38 
47.35 
110.92 
50.33 
116.53 
52,87 
91.18 
41,36 
Fourteen, 
290 
pound, 
kilogram, 
79.29 
35.97 
83.05 
37,68 
88.07 
39,96 
92.14 
41,80 
96.21 
43.65 
99.88 
45.31 
103.52 
46.97 
107.22 
48.65 
110.94 
50,34 
117.76 
53.43 
125.00 
56,71 
100.32 
45.50 
Fifteen, 
• 255 
pound, 
kilogram, 
86.87 
39.41 
92.14 
41.80 
98.48 
44,68 
102.30 
46,42 
104.52 
47.42 
107.13 
48.61 
110.67 
50,21 
115.05 
52.20 
119.60 
54,26 
125.82 
57,08 
132.80 
60,25 
108.42 
49.17 
Sixteen, 
238 
pound, 
kilogram, 
88.15 
40.00 
93.40 
42,37 
100.03 
45.38 
104.62 
47,46 
108.43 
49,20 
112.80 
51.18 
116.97 
53,07 
120.93 
54,86 
125.66 
57.01 
131.28 
59,56 
136.26 
61.82 
112.97 
51.24 
Seventeen, 
168 
pound, 
kilogram, 
93.52 
42.43 
97.90 
44.42 
104.53 
47.42 
108.16 
49.07 
110.99 
50,36 
113.88 
51,58 
118.70 
53.86 
122.96 
55,79 
127.96 
58.06 
135.83 
61.63 
141.07 
64.00 
115.84 
52.54 
Eighteen, , 
118 
pound, 
95.93 
99.02 
102.85 
105.62 
110.71 
113.33 
117.91 
123.72 
128,20 
133.64 
138.40 
115.80 
kilogram, 
43.52 
44.92 
46.67 
47.92 
50,23 
51,42 
53.50 
56.13 
58,16 
60.63 
62.79 
52,52 
Table No. 11. Calculated from Table 14 or Original Article. 
Weights of Boston School-girls of American Parentage. No. 34.] 
THE GROWTH OF CHILDREN. 
Number 
Unit of 
Values at the Following Percentile 
Grades. 
ft 
Average. 
Age at 
Last Birthday. 
Observa- 
tions. 
Weights. 
5 
Per Cent. 
10 
Per Cent. 
so 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
GO 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
05 
Per Cent. 
Five, . 
236 
pound, 
kilogram, 
32.78 
14.87 
34.43 
15.62 
35.95 
16,31 
37.47 
17.00 
38.64 
17.53 
39.61 
17.97 
40.58 
18.41 
41.55 
18,85 
43.14 
19,57 
45.24 
20.53 
47.16 
21,40 
39.63 
17.97 
Six, . 
395 
pound, 
kilogram, 
35.48 
16.10 
37.24 
16.90 
39.11 
17,74 
40.52 
18,39 
41.93 
19.02 
43.18 
19.59 
44.42 
20.15 
45.67 
20.72 
47.47 
21.54 
49.47 
22,44 
51.60 
23.40 
43.21 
19,60 
Seven, 
426 
pound, 
kilogram, 
39.50 
17.92 
41.36 
18,76 
'43.12 
19,56 
44.47 
20.17 
45.82 
20.79 
47.20 
21.42 
48.77 
22,13 
50.39 
22.86 
52.73 
23,92 
55.69 
25,26 
57.54 
26.10 
47.64 
21.61 
Eight, 
486 
pound, 
kilogram, 
42.31 
19.20 
43.74 
19.85 
46.43 
21,07 
48.48 
22.00 
50.39 
22.86 
51.94 
23,56 
53.48 
24.26 
55.30 
25.09 
57.26 
25.98 
60.25 
27.33 
62.14 
28.19 
51.80 
23.50 
Nine, . 
416 
pound, 
kilogram, 
45.96 
20.86 
48.17 
21,86 
51.20 
23.22 
53.25 
24,15 
55.01 
24.95 
56.59 
25.67 
58.20 
22,77 
60.05 
27,24 
61.90 
28.08 
65.43 
29.69 
68.99 
31,30 
56.76 
25.75 
Ten, . 
379 
pound, 
kilogram, 
50.40 
22,86 
52.35 
23.75 
65.45 
25.15 
57.98 
26.30 
59.67 
27.06 
61.36 
27,83 
63.51 
28,81 
65.95 
29.92 
68.29 
30.S8 
71.35 
32,37 
73.87 
33,51 
61.59 
27.94 
Eleven, 
340 
pound, 
kilogram, 
54.25 
24.60 
56.37 
25.57 
59.58 
27,02 
62.13 
28.19 
64.36 
29.19 
66.68 
30,25 
69.25 
31,41 
72.18 
32,75 
75.75 
34,37 
80.91 
36,71 
85.66 
38,87 
67.83 
30.77 
Twelve, 
307 
pound, 
kilogram, 
59.17 
26.84 
61.63 
27.96 
66.04 
29.96 
69.03 
31,31 
71.98 
32.65 
75.09 
34.07 
78.63 
35.68 
82.33 
37,36 
85.95 
39.00 
92.29 
41,87 
97.85 
44,40 
76.15 
34.55 
Thirteen, . 
278 
pound, 
kilogram, 
64.18 
29.11 
68.80 
31.21 
73.93 
33,54 
77.22 
35.04 
81.53 
36.99 
85.85 
38.96 
89.83 
40.76 
93.32 
42.34 
97.45 
44.21 
103.89 
47.13 
109.60 
49,72 
85.76 
38,91 
Fourteen, . 
192 
pound, 
kilogram, 
74.80 
33.93 
79.25 
35.95 
83.05 
37,68 
88.40 
40,11 
92.33 
41.89 
95.90 
43,51 
99.56 
45.16 
103.60 
47.00 
108.26 
49.12 
113.93 
51.69 
122.53 
55.59 
96.36 
43.71 
Fifteen, 
95 
pound, 
kilogram, 
77.40 
35.12 
83.25 
37.77 
88.67 
40,23 
93.33 
42.34 
97.56 
44,26 
100.62 
45,65 
103.33 
46.88 
105.87 
48.03 
110.50 
50.14 
117.33 
53.24 
130.40 
59.16 
100.46 
45.56 
Sixteen, 
49 
pound, 
kiloglam, 
87.60 
39,75 
93.80 
42,55 
97.44 
44,21 
99.88 
45.31 
101.84 
46,20 
105.60 
47.91 
109.52 
49.69 
115.73 
52,51 
120.56 
54,69 
130.20 
59.07 
136.00 
61,70 
108.56 
49,24 
Seventeen, 
Eighteen, 
".1 
pound, 
kilogram, 
98.40 
44.64 
100.80 
45.73 
104.40 
47,36 
106.SO 
48.45 
108.40 
49,18 
110.00 
49.91 
111.60 
50,63 
113.20 
51.36 
124.40 
56.43 
144.40 
65,51 
161.20 
73,14 
115.82 
52.49 
Table No. 12.— Calculated from Table 15 op Original Article. 
Weights of Boston School-girls of Irish Parentage. 494 
STATE BOAED OF HEALTH. 
[Pub. Doc 
A geometrical construction of a special case will perhaps 
best serve to place the matter in a clear light. Let us sup- 
pose one thousand grown men standing in line arranged 
according to height. The heads of these men will form a 
curved line represented in its general form by the curve ST 
in Fig 1. In this diagram the line SO represents the height 
of the shortest and the line TO1 that of the tallest man. The 
curve ST, representing the heights of the intermediate men, 
is approximately a straight line in a large part of its course 
but bends up sharply at the right and down sharply at the 
left owing to the presence of a few very tall and a few very 
short men. Mediocrity is the rule and extremes the excep- 
tion in height as in everything else. 
If now we divide this row of men into two equal parts 
and ascertain the height of the five hundredth man in the 
row (or, more accurately speaking, the height halt way 
between that of the five hundredth and that of the five 
hundred and first man) we shall have a value below which 
one half and above which the other half of the observations 
lie. This value is termed by Galton the value of the fifty 
percentile grade, or the median value, and is designated by No. 34.] 
THE GROWTH OF CHILDREN. 
the letter M. In the same way the values at other percen- 
tile grades may be determined by dividing the row at points 
corresponding to various percentages of the total number of 
observations. The percentile grades indicated in Fig. 1 are 
those adopted by Gallon, and are practically sufficient to 
indicate the character of the curve. With a very large 
number of observations it would of course be possible to 
determine values below five per cent, and above ninety-five 
per cent., but in anthropometrical investigations with existing 
data it does not seem wise to go beyond these limits. 
It is evident that the value M will tend to approximate to 
the average value of all the observations and will be identical 
with it when the curve ST is symmetrically disposed on both 
sides of M, i. e., when the values at sixty, seventy, eighty, 
ninety and ninety-five per cent, exceed M by the same amount, 
respectively, by which the values at forty, thirty, twenty, 
ten and five per cent, fall short of it. If A represent the 
average value of all the observations, then the value of M—A 
will be a measure of the direction and extent of the asym- 
metry of the curve ST, for this value will be zero when the 
curve is symmetrical, positive when the values at the lower 
'percentile grades fall short of M more than those at the higher 
grades exceed it, and negative when the reverse is the case. 
Let us now apply this test to the data in our possession, 
confining our attention for the present to tables 1, 4, 7 and 
10, which give the total number of observations irrespective 
of nationality. By subtracting the average from the median 
values in these four tables the following table (No. 12a) has 
been constructed : 
Table 12a.— Values of M—A. 
Age at Last Birthday. 
Heights in Inches. 
Weights in Pounds. 
Boys. 
Girls. 
Boys. 
Girls. 
Five 
J 
-0.10 
+0.14 
—0.13 
—0.03 
Six, 
-0.12 
+0.05 
—0.15 
—0.17 
Seven, 
-0.09 
+0.11 
—0.17 
—0.16 
Eight, 
-0.08 
+0.07 
—0.35 
—0.59 
Nine 
-0.08 
+0.17 
—0.28 
—0.45 
Ten, 
-0.05 
+0.12 
—0.12 
—0.95 
Eleven, 
- 
+ .07 
—0.01 
—0.44 
—1.22 
Twelve, 
0.00 
0.00 
—1.18 
—1.23 
Thirteen, 
-0.23 
+0.24 
—1.94 
—0.63 
Fourteen, . . . • • 
-0.28 
+0.26 
—1.88 
—0.68 
Fifteen 
* 
-0.07 
+0.11 
—1.10 
—0.97 
Sixteen, 
- 
-0.35 
+0.19 
+0.37 
—0.76 
Seventeen 
+0.05 
+0.26 
—0.92 
—2.77 
Eighteen, 
+0.13 
—0.10 
1 
—0.84 
—2.52 496 
STATE BOAED OF HEALTH. 
[Pub. Doc. 
An examination of this table or of the curves constructed 
from it, as given in Plate 1, shows that the asymmetry of 
PLATE I. 
NCHES. 
HEIGHTS OF BOSTON SCHOOL CHILDREN 
MEDIAN MINUS AVERAGE VALUES (M-A) 
AGE AT LAST BIRTHDAY 
WEIGHTS OF BOSTON SCHOOL CHILDREN. 
MEDIAN MINUS AVERAGE VALUES (M-A) 
AGE AT LAST BIRTHDAY No. 34.] 
THE GROWTH OF CHILDREN. 
497 
the curves of percentile grades varies very much, at different 
ages, both in direction and amount. The variation in the 
value of M—A in the curves of height is much the same as 
that in the curves of weight for each sex considered by itself, 
but there is a great difference between the two sexes. This 
difference shows itself most distinctly between the ages of 
eleven and fifteen years. During this time a rise in the 
curves for the males coincides with a fall in those for the 
females, while before and after this period the curves, as a 
rule, rise and fall together. We must conclude, therefore, 
that the rate of annual increase both in height and weight is 
different at different percentile grades, or, in other words, 
that large children grow differently from small ones, and 
moreover, that between the ages of eleven and fifteen years 
there is a striking difference in the mode of growth of the 
two sexes. The significance of this conclusion will be made 
clearer by an examination of the curves constructed directly 
from the tables of percentile grades. Curves of this sort are 
presented in plates 2, 3, 4 and 5, constructed from tables 1, 
4, 7 and 10, containing the total number of observations irre- 
spective of nationality. Similar curves have been obtained 
from the remaining tables in which the observations are 
grouped according to the nationality of the parents, but as 
they are less regular, owing to the smaller number of obser- 
vations from which they are constructed, and lead to no 
additional conclusions, it has not been thought worth while 
to present them. 
A glance at the curves on plates 2-5 shows at once the 
nature of the asymmetry, the existence of which is indicated 
by the curves on Plate 1. It will be observed that during the 
earlier years of school life the curves for the successive years 
are fairly symmetrical, which is in harmony with the previous 
observation that in these years the value of M—A does not 
differ widely from zero. At about ten years of age in girls 
and eleven or twelve years in boys, the curves become dis- 
tinctly asymmetrical, owing to the values increasing more 
rapidly at the higher than at the lower percentile grades. 
At the age of twelve or thirteen years in girls and fourteen 
or fifteen years in boys an asymmetry in the opposite direc- 
tion shows itself, since at this period the values are increasing 498 
STATE BOARD OF HEALTH. 
[Pub. Doc 
PLATE 2. OrROM table t.) 
HEIGHTS OF BOSTON SCHOOLBOYS. 
IRRESPECTIVE OF NATIONALITY. No. 34.] 
THE GROWTH OF CHILDREN. 
499 
PLATE 3.(f ROM TABLE 4-.) 
WEIGHTS OF BOSTON SCHOOLBOYS. 
IRRESPECTIVE OF NATIONALITY. 
PERCENTILE GRADES. 500 
STATE BOARD OF HEALTH. 
[Pub. Doc 
PLATE 4. (from table 7 ) 
HEIGHTS OF BOSTON SCHOOLGIRLS. 
IRRESPECTIVE OF NATIONALITY. THE GROWTH OF CHILDREN. 
501 
No. 34.] 
PLATE 5. (FROM TABLE 10.) 
WEIGHTS OF BOSTON SCHOOLGIRLS.- 
IRRESPECTIVE OF NATIONALITY. 
PERCENTILE GRADES 502 
STATE BOARD OF HEALTH. 
[Pub. Doc. 
more rapidly at the lower than at the higher percentile grades. 
These changes correspond accurately with the fall and rise in 
the value of M—A, as shown on Plate 1. 
In the original article on the growth of children it was' 
shown that about two years before the age of puberty there 
is a period during which the growth in both height and 
weight shows a distinct acceleration. Now, the rate of growth 
at the various percentile grades is represented on plates 2-5 
by the vertical distances between the curves corresponding to 
the successive years ; and an inspection of these curves shows 
that the prepubertal period of accelerated growth, already 
shown to exist by a comparison of average heights and 
weights at different ages, occurs all along the line, but that 
it occurs earlier at the higher than at the lower percentile 
grades. In other words, we find that the above-mentioned 
variations in the value of M—A are due to the fact that the 
period of acceleration, which is such a distinct phenomenon 
in the growth of children, occurs at an earlier age in large 
than in small children. 
The significance of this observation will be best understood 
by an examination of the annual increase in height and 
weight of children at the different percentile grades. These 
values, which are readily obtained from the preceding tables 
by subtracting the height or weight at any year from that of 
the year next following, are shown in tables 13, 14, 15 and 
16, which have been calculated from tables 1, 4, 7 and 10 
respectively.* 
*lt will be noticed that in tables 1,4, 7 and 10 the ages are given “at the last birth- 
day.” Hence the average age of the children thus grouped together will be six months 
greater than the age given in the tables. For instance, in Table 1, five years six 
months is the average age of the 848 boys whose heights at various percentile grades 
are given in the first line. Now since the figures in the tables of annual increase are 
the differences between the successive heights and weights in tables 1, 4, 7 and 10, it 
is evident that they express the yearly growth precisely at the age given in the tables. 
The first line in Table 13, for instance, is the annual growth in height of boys of six 
years of age. No. 34.] 
THE GROWTH OE CHILDREN. 
503 
Age. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
95 
Per Cent. 
Six, 
2.27 
2.22 
2.16 
2.17 
2.16 
2.20 
2.22 
2.14 
2.18 
2.34 
2.30 
2.18 
Seven, 
1.84 
1.89 
1.87 
1.92 
1.96 
1.99 
2.02 
2.01 
1.99 
2.14 
1.99 
Eight 
1.97 
1.95 
2.05 
2.04 
2.01 
2.00 
2.02 
2.06 
2.10 
2.15 
2.02 
Nine 
1.94 
1.89 
1.89 
1.92 
1.93 
1.94 
1.97 
1.99 
2.03 
2.04 
1.93 
Ten, 
1.80 
1.73 
1.75 
1.83 
1.96 
2.04 
2.07 
2.16 
2.24 
2.37 
1.99 
Eleven, 
1.34 
1.53 
1.63 
1.65 
1.67 
1.70 
1.79 
1.74 
1.69 
1.67 
1.65 
Twelve 
1.64 
1.77 
1.70 
1.71 
1.71 
1.71 
1.73 
1.86 
2.21 
2.38 
1.78 
Thirteen, 
1.62 
1.74 
1.91 
1.91 
1.87 
2.09 
2.29 
2.44 
2.72 
2.85 
2.10 
Fourteen, 
2.08 
2.32 
2.38 
2.41 
2.62 
2.64 
2.76 
3.00 
3.14 
3.16 
2.67 
Fifteen, 
1.98 
2.41 
2.33 
2.32 
2.55 
2.77 
2.87 
2.90 
2.68 
2.24 
2.01 
2.42 
Sixteen, 
3.14 
3.34 
3.36 
3.25 
2.98 
2.71 
2.33 
1.99 
1.80 
1.96 
2.70 
Seventeen 
1.39 
1.05 
1.23 
0.99 
0.86 
0.95 
1.23 
1.27 
1.33 
1.08 
1.16 
Table 13. Showing Annual Growth in Inches of Boston School-boys irrespective of Nationality. 504 
STATE BOARD OF HEALTH 
Pub. Doc. 
Age. 
- 
Values 
at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
CO 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
93 
Per Cent. 
Six, 
3.70 
3.71 
3.89 
3.98 
4.00 
4.19 
4.21 
4.23 
4.44 
4.20 
4.08 
Seven, . 
3.48 
3.42 
3.66 
3.77 
3.88 
4.00 
4.22 
4.43 
4.93 
5.45 
3.90 
Eight, . 
4.05 
4.46 
4.48 
4.57 
4.67 
4.96 
5.04 
5.58 
5.47 
6.94 
4.85 
Nine, . 
4.38 
4.79 
4.77 
5.09 
5.38 
5.39 
5.40 
5.45 
5.91 
6.01 
5.31 
Ten, . 
4.10 
4.73 
5.32 
5.84 
6.23 
6.61 
6.83 
7.35 
7.92 
8.18 
6.07 
Eleven, 
4.01 
4.38 
4.62 
4.79 
4.64 
4.56 
4.69 
4.92 
5.07 
5.65 
6.82 
4.88 
Twelve, 
4.80 
4.84 
5.20 
5.51 
5.72 
6.00 
6.13 
7.08 
7.84 
9.47 
10.71 
6.74 
Thirteen, 
6.46 
6.24 
6.30 
6.69 
7.16 
7.92 
8.27 
9.51 
11.29 
12.14 
7.92 
Fourteen, 
5.63 
7.39 
8.25 
9.32 
10.13 
10.89 
12.23 
12.93 
14.60 
16.03 
10.07 
Fifteen, 
9.03 
9.86 
11.33 
12.27 
12.97 
13.86 
13.64 
14.36 
14.09 
14.57 
12.19 
Sixteen, 
12.89 
16.62 
15.84 
15.03 
15.38 
13.79 
12.85 
11.94 
10.95 
8.60 
13.91 
Seventeen, . 
8.25 
10.90 
6.36 
5.95 
5.61 
5.19 
7.29 
8.54 
7.08 
8.37 
8.40 
6.48 
Table 14.— Showing Annual Increase in Pounds of Boston School-boys irrespective of Nationality. No. 34. 
THE GROWTH OF CHILDREN. 
505 
Age. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
30 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
50 
Per Cent. 
60 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
OO 
Per Cent. 
95 
Per Cent. 
Six, 
2.03 
2.02 
2.01 
2.00 
2.00 
1.97 
1.95 
2.00 
2.09 
2.16 
2.13 
2.06 
Seven, . 
2.11 
2.02 
2.04 
2.25 
2.19 
2.23 
2.29 
2.32 
2.34 
2.24 
2.34 
2.17 
Eight, . 
1.67 
1.79 
1.99 
1.83 
1.95 
2.02 
2.09 
2.11 
2.19 
2.42 
2.32 
2.06 
Nine, . 
1.73 
1.65 
1.73 
1.88 
1.92 
1.89 
1.85 
1.81 
1.76 
1.77 
1.78 
1.79 
Ten, . 
1.68 
1.81 
1.82 
1.85 
1.87 
1.92 
1.96 
2.00 
2.09 
2.25 
2.51 
1.97 
Eleven, 
1.84 
1.90 
1.86 
1.88 
1.85 
1.95 
2.12 
2.24 
2.35 
2.47 
2.30 
2.08 
Twelve, 
1.92 
1.97 
2.10 
2.19 
2.42 
2.47 
2.43 
2.49 
2.63 
2.68 
2.85 
2.46 
Thirteen, 
2.36 
2.26 
2.30 
2.47 
2.46 
2.52 
2.60 
2.53 
2.36 
2.06 
1.99 
2.28 
Fourteen, 
2.26 
2.48 
2.36 
2.10 
1.98 
1.80 
1.52 
1.37 
1.19 
1.20 
1.25 
1.78 
Fifteen, 
1.52 
1.31 
1.22 
1.20 
1.08 
1.01 
1.02 
1.04 
1.21 
1.16 
0.95 
1.16 
Sixteen, 
0.43 
0.35 
0.39 
0.39 
0.49 
0.57 
0.64 
0.63 
0.53 
0.62 
0.59 
0.49 
Seventeen, 
0.44 
0.23 
0.39 
0.42 
0.40 
0.31 
0.26 
0.15 
0.11 
0.26 
• 0.33 
Table 15.— Showing Annual Growth in Inches of Boston School-girls irrespective of Nationality. 506 
STATE BOARD OF HEALTH. 
FPub. Doc. 
Age. 
Values at the Following Percentile Grades. 
Average. 
5 
Per Cent. 
10 
Per Cent. 
20 
Per Cent. 
30 
Per Cent. 
40 
Per Cent. 
30 
Per Cent. 
00 
Per Cent. 
70 
Per Cent. 
80 
Per Cent. 
90 
Per Cent. 
93 
Par Cent. 
Six, . 
2.97 
2.82 
3.22 
3.09 
3.24 
3.48 
3.70 
3.91 
4.12 
4.35 
4.48 
3.62 
Seven, . 
3.G2 
3.51 
3.83 
3.94 
4.05 
4.19 
4.34 
4.56 
4.89 
5.58 
5.20 
4.18 
Eight, . 
3.57 
3.61 
3.98 
3.96 
4.43 
4.15 
4.74 
5.08 
4.79 
4.96 
5.04 
4.58 
Nine, . 
3.55 
3.96 
4.31 
4.89 
4.69 
5.17 
4.83 
5.05 
5.33 
5.51 
7.36 
5.03 ' 
Ten, . 
4.10 
3.98 
4.10 
4.42 
4.56 
4.78 
5.42 
5.92 
6.46 
7.60 
6.93 
5.28 
Eleven, 
3.82 
3.97 
4.35 
4.78 
5.36 
6.22 
6.78 
7.12 
8.04 
10.28 
12.38 
6.49 
Twelve, 
5.61 
6.81 
7.71 
8.22 
8.61 
9.46 
10.02 
10.68 
11.16 
11.00 
13.46 
9.47 
Thirteen, 
6.06 
7.40 
7.84 
8.69 
10.39 
10.94 
11.48 
12.42 
13.89 
13.76 
12.69 
10.34 
Fourteen, 
10.82 
9.99 
10.60 
10.81 
10.08 
9.73 
9.25 
9.22 
7.82 
8.65 
9.31 
9.78 
Fifteen, 
6.82 
8.44 
9.67 
9.45 
8.49 
7.36 
7.20 
6.71 
7.70 
7.02 
7.49 
7.65 
Sixteen, 
5.08 
4.71 
3.62 
3.91 
4.79 
6.16 
7.36 
7.56 
7.15 
6.85 
3.72 
5.95 
Seventeen, 
4.73 
4.24 
5.27 
4.07 
2.74 
1.49 
1.41 
2.80 
2.75 
4.89 
5.21 
3.50 
Table 16. Showing Annual Increase in Pounds of Boston School-girls irrespective of Nationality. No. 34.] 
THE GROWTH OF CHILDREN. 
507 
The conclusions to be drawn from these tables will be most 
readily understood by an examination of the curves on plates 
6 and 7, which have been constructed from them, the carves 
PLATE 6.(frROM tab!-es i 3& is.) BOYS GIRLS 
ANNUAL INCREASE IN INCHES 508 
STATE BOAED OF HEALTH. 
[Pub. Doc. 
representing the yearly growth of the two sexes being, for easier 
comparison, plotted on the same system of co-ordinates. 
PLATE 7 (from tables 14.& is) BOYS-' GIRLS” 
ANNUAL INCREASE IN POUNDS. No. 34.] 
THE GROWTH OF CHILDREN. 
509 
The following are the most obvious conclusions 
1. The maximum yearly growth in both height and weight 
is at all percentile grades greater in boys than in girls, and 
occurs in boys two or three years later than in girls. 
2. The age at which this maximum yearly growth in 
height and weight is reached is, in both sexes, earlier at the 
higher than at the lower percentile grades, the range being 
from twelve to fourteen years for girls and from fourteen to 
sixteen years tor boys. In other words, large children make 
their most rapid growth at an earlier age than small ones. 
8. The curves representing the annual growth of boys 
are characterized on either side of the maximum by a steeper 
rise and fall in the lower than in the higher percentile grades, 
though the maximum itself may be quite as high in the former 
as in the latter grades. This indicates that the above-men- 
tioned period of accelerated growth in large boys differs 
from that in small boys rather in duration than in intensity. 
In girls a difference of this sort does not seem to exist. 
4. In boys at eleven years of age there is a period of 
remarkably slow growth both in height and weight, the curves 
of annual increase in nearly all the percentile grades reach- 
ing at this age a lower point than for several years preceding 
or subsequent to this age. In girls a similar but less marked 
period of retarded growth in height is to be noticed at nine 
years of age, but the rate of growth in weight does not seem 
to suffer a corresponding diminution.* 
One of the conclusions reached in the original article to 
which reference has been made was that “ at about thirteen 
or fourteen years girls in this community are, during more 
than two years, both taller and heavier than boys at the same 
age, though before and after that period the reverse is the 
* It is interesting, however, to notice that in the curves constructed by Dr. 
Stevenson (See‘‘ Lancet,” Sept. 22, 1888) from English and American statistics, and 
representing the annual increase in weight of “ hoys and girls of the English-speaking 
races,” the period of retarded growth is a marked phenomenon in both sexes, occur- 
ring in boys at eleven and in girls at nine years of age. 
See also “ Axel Key, Die? Pubertatsentwickelung.” (Verhandlungen des X inter- 
nationalen medicinschen Congresses, Berlin, 1890. Bd. 1., p. 67.) This observer 
finds that in Sweden the period of least increase in height and weight occurs at ten 
years for boys and nine years for girls. 510 
STATE BOARD OF HEALTH. 
[Pub. Doc. 
case.” The dependence of this phenomenon upon the fact 
that the prepubertal period of accelerated growth occurs 
earlier in girls than in boys was also pointed out. It will be 
interesting now to inquire in what way this period of female 
superiority is affected by the fact that the maximum rate of 
growth is reached earlier in the higher than in the lower 
percentile grades. The influence of this circumstance is 
readily understood from an inspection of the curves on 
plates 8 and 9, which have been constructed from the fig- 
ures on plates 1, 4, 7 and 10. Here the absolute heights and 
weights of boys and girls of the same percentile grade are 
plotted on the same system of co-ordinates, while the ordi- 
nates for the successive percentile grades differ from each 
other by five inches or twTenty-five pounds respectively. 
In this way the curves are brought vertically over one 
another and a comparison between them is facilitated. The 
points where the curves of growth of the two sexes intersect 
each other are joined by dotted lines, in order that the 
periods of female superiority at the various percentile grades 
may be readily compared with each other. A glance at the 
curves suffices to show that the period of female superiority 
is to be observed at all percentile grades both in height and 
weight, and, moreover, that it both begins and ends earlier in 
the higher than in the lower percentile grades. Thus, in the 
ninety-five percentile grade, girls begin to exceed boys in 
height at the age of ten years four months and are in turn 
surpassed by them at thirteen years, while in the five per- 
centile grade girls do not surpass boys in height till they 
are eleven years five months old and boys do not regain 
their superiority till they are fifteen years four months of 
age. It will be also noticed that the duration of the period 
of female superiority varies quite regularly with the percen- 
tile grade, but that the variations in height and weight are 
in opposite-directions. This is indicated by the fact that 
the above-mentioned dotted lines converge upward in the 
curves of height and downward in those of weight. In 
other words, we may say that, when growing children of 
both sexes are compared together by corresponding percen- 
tile grades, the period of female superiority in height is less 
conspicuous in tall than in short children, while the period No. 34.] 
THE GROWTH OF CHILDREN. 
511 
PLATE 8. (from tables ia z) BOYS GIRLS 
i HEIGHTS OF BOSTON SCHOOL CHILDREN. STATE BOARD OF HEALTH. 
[Pub. Doc. 
PLATE 9 (from tables 4 & io.) BOYS GIRLS 
WEIGHTS OF BOSTON SCHOOLCHILDREN No. 34.] 
THE GROWTH OF CHILDREN. 
513 
of female superiority in weight is a more marked phenome- 
non in heavy than in light children. 
Amdng the advantages of this method of discussing anthro- 
pometrical results may be mentioned the facility which it 
affords for comparing the rates of growth of children of 
different nationalities by determining the percentile rank 
of the average children of one nationality referred to those 
of another nationality as a standard. We may take, for 
instance, the observations of Pagliani* on Italian children, 
and those of Erismannf on the employees in Russian fac- 
tories, and calculate the percentile rank of the children at 
successive ages when referred to Boston children as a 
standard. The result of this calculation is given in the 
following table : 
Table 17. Showing the Percentile Rank of Italian and Russian Chil- 
dren compared ivith those of the Boston Public Schools. 
Percentile Bank. 
Age at Last Birthday. 
Italian (Pagliani). 
Russian (Erismann). 
Boys. 
Girls. 
Boys. 
Girls. 
Five, . 
below 5 
below 5 
- 
- 
Six, 
5.6 
below 5 
- 
- 
Seven, . 
22.1 
9.2 
75.9 
80.7 
Eight, . 
26.5 
15.8 
56.6 
63.4 
Nine, 
31.4 
29.1 
48.9 
76.4 
Ten, 
20.0 
'28.0 
40.6 
51.9 
Eleven, 
16.4 
25.5 
42.5 
48.8 
Twelve, 
16.1 
24.1 
36.6 
39.0 
Thirteen, 
21.7 
23.7 
28.7 
26.9 
Fourteen, 
21.2 
30.0 
26.5 
22.8 
Fifteen, 
23.7 
29.5 
29.1 
21.4 
Sixteen, 
16.2 
32.4 
17.7 
23.4 
Seventeen, 
13.1 
32.2 
18.6 
22.0 
Eighteen, 
6.6 
34.3 
15.0 
23.6 
An examination of this table shows that Italian children of 
both sexes are, in early life, very much smaller than Boston 
* Lo Sviluppo TJmano, p. 37- 
t Untersuchungen liber die korperlichc Entwickelung der Fabrikarbeiter in Zen- 
tralrussiand, Tubingen, 1889. A very thorough investigation based upon measure- 
ments of over 100,000 individuals. 514 
STATE BOARD OF HEALTH. 
[Pub. Doc. 
children of the same age, and, though they afterwards increase 
in relative size, they never reach a higher percentile than 31.4 
for boys and 32.4 for girls. 
The Russian children show in general, with increasing age, 
a progressive diminution in percentile rank which is probably 
to be accounted for by the fact that during the earlier period 
of life only children who are unusually well developed 
physically are likely to find their way into manufactories. 
The children from seven to twelve years of age are therefore 
to some extent selected cases and do not represent the aver- 
age development of the working population. 
It will be noticed that throughout this article it has been 
assumed that the changes from year to year in the values of 
the height and weight at the various percentile grades repre- 
sent the rate of growth of large, small and medium-sized 
children respectively. This assumption may be criticized on 
the ground that the values at the various percentile grades 
do not represent the average measurements of particular 
groups of growing children but are merely limiting values, 
on either side of which lie certain percentages of the total 
number of observations on children of a certain age. To 
determine how much importance is to be attached to this 
objection it will be necessary to inquire within what limits 
the percentile rank of a growing child may under normal 
circumstances vary from year to year, for it is obvious that 
if growing children remain practically in the same percentile 
grade during the whole period of adolescence a comparison 
of the values at the various percentile grades in successive 
years will, to all intents and purposes, show the annual 
increase in height and weight of groups of children belonging- 
in and about those percentile grades, i.e., it will really give 
us the rate of growth of large, small and medium-sized 
children. Aow it is evident that a close maintenance of a 
given percentile rank by a growing child is by no means a 
universal rule, for it is a matter of common observation that 
very small babies sometimes grow up into very large men 
and women. Such cases, however, always attract attention 
from their obviously exceptional character and indicate that, 
as a rule, there is a certain degree of correspondence between 
the size of the child and that of the adult. No. 34.] 
THE GROWTH OF CHILDREN. 
515 
General impressions with regard to such questions are, of 
course, of very little value, and before any definite conclu- 
sion can be reached it will be necessary to collect large 
numbers of observations on growing children of both sexes, 
each individual being measured in successive years or, still 
better, several times each year, and the percentile rank at 
each age determined. Such determinations may be made by 
means of tables 1-10, or by the curves on plates 2-5 con- 
structed from them, but in practice it will be found more 
convenient to make use of such curves as those on plates 
10-13, which have been constructed* with a view to this 
special purpose. 
In these plates, which have been constructed only from the 
tables which present the total number of observations irre- 
spective of nationality, the age in years and months is given 
on the sides, the percentile rank at the top and bottom, while 
the curved lines traversing the plate represent successive 
inches or pounds. The use of the curves will be best under- 
stood by an example. Let us suppose, for instance, that a 
boy ten years five months old measures fifty inches in height, 
and it is desired to ascertain his percentile rank. On Plate 
10 the horizontal line corresponding to ten years five months 
is to be followed to its point of intersection with the fifty- 
inch curve. This point of intersection will be found to lie 
on the vertical line corresponding to twenty-five per cent. 
This means that the boy is taller than twenty-five per cent, 
and shorter than seventy-five per cent, of the boys of his 
age. A height of fifty-one inches at the same age would 
give a percentile rank of forty-one percent., fifty-two inches 
fifty-seven per cent., fifty-three inches seventy-four per 
cent., etc. 
If we were in possession of a few hundred sets of observa- 
tions on growing children, each child being measured and 
weighed annually or semiannually during the period of 
adolescence and his percentile rank determined in the 
* Such curves may be constructed by calculating for each age the percentile rank 
corresponding to each inch or pound by interpolation in tables such as Nos. 1-12, 
or, still better, from tables such as Nos. 4-15 of the original article, by direct ad- 
dition to the percentages corresponding to the successive inches or pounds. 516 
STATE BOARD OF HEALTH. 
[Pub. Doc. 
PLATE 10 
SHOWING PERCENTILE RANK OP BOYS 
OF GIVEN AGE AND HEIGHT No. 34.] 
THE GROWTH OF CHILDREN. 
517 
PLATE 1 I 
SHOWING PERCENTILE RANK OF BOYS 
OF GIVEN AGE AND WEIGHT. 518 
STATE BOARD OF HEALTH. 
[Pah. Doc 
PLATE 12 
SHOWING PERCENTILE RANK OF GIRLS 
OF GIVEN AGE AND HEIGHT. No. 34.] 
THE GROWTH OF CHILDREN. 
519 
PLATE 13 
SHOWING’ PERCENTILE RANK OF GIRLS 
OF' GIVEN AGE AND WEIGHT: 520 
STATE BOAKD OF HEALTH. 
[Pub. Doc. 
above manner, we should be able to draw fairly accurate 
conclusions as to the normal range of variation in percentile 
rank during the period of growth, and to determine how far 
the rate of growth in the earlier years of life is to be regarded 
as an indication of the size to be subsequently attained. Un- 
fortunately records of this sort have been rarely kept and 
still more rarely published. Those which are accessible to 
the writer represent in most cases the result of observations 
upon children above the ninety-five per cent, grade in both 
height and weight, i.e., of a size at which the above tables 
do not permit us to determine the percentile rank with any 
accuracy. As an example of the kind of record which it is 
important to secure the following table is presented, showing 
the percentile rank in height and weight of two growing 
girls from the ages of six to fifteen years : 
Table 18. Showing Absolute Height and Weight and Percentile Rank in 
Height and Weight of two Girls E and E at Various Ages from Six to 
Fifteen Years. 
M 
Years. 
Oi 
4- 
to 
CO 
00 
05 
> 
M 
1-1 
M 
45. 
n« 
(C0 
CO 
05 
»0|*— 
OO 
.Months. 
05 
O' 
o« 
07 
4^ 
°° 
07 
CO 
r* 
07 
Inches. 
a 
~-7 
GO 
o 
07 
oo 
b 
to 
CO 
05 
w 
GO 
O 
CO 
CO 
GO 
O' 
GO 
07 
CO 
GO 
CO 
CO 
to 
CO 
GO 
GO 
CO 
Per Cent. 
a 
b 
b 
07 
to 
b 
—7 
b 
b 
Rank. 
H 
W 
M 
Years. 
o« 
to 
O 
CO 
GO 
05 
> 
a 
Ox 
05 
05 
05 
05 
05 
05 
05 
CO 
05 
W*- 
Months. 
j_, 
CO 
4^ 
IO 
CO 
O 
CO 
GO 
4- 
CO 
05 
07 
CO 
07 
4- 
07 
o 
Pounds. 
a 
CO 
to 
b 
-I 
O' 
05 
b 
GO 
CO 
o 
CO 
CO 
92 
CO 
o 
CO 
CO 
CO 
CO 
CO 
CO 
CO 
Per Cent. 
a 
h 
+ 
+ 
-7 
GO 
b 
b 
CO 
-7 
Rank. 
M 
M 
Years. 
CO 
to 
to 
h-1 
o 
CO 
GO 
05 
> 
H 
1 
CD 
CO 
M 
O 
o 
o 
O 
o 
o 
Months. 
05 
07 
07 
4^ 
45* 
71 
07 
to 
o 
r1 
Inches. 
W 
to 
05 
to 
GO 
CO 
*“* 
to 
GO 
g 
CO 
o 
00 
4- 
§§ 
CO 
05 
CO 
07 
CO 
05 
§ 
CO 
o 
Per Cent. 
a 
1 
oo 
CO 
b 
05 
b 
w 
- 
07 
b 
Rank. 
Years. 
CO 
00 
05 
r~ 
o 
a 
1 
O 
O 
o 
o 
o 
o 
o 
o 
o 
Months. 
H-* 
r-i 
GO 
GO 
05 
05 
(-4 
°7 
4*. 
o 
CO 
00 
Pounds. 
to 
M 
b 
he 
to 
M 
CO 
05 
to 
CO 
o 
05 
CO 
GO 
GO 
4- 
00 
CO 
o 
Per Cent. 
a 
1 
to 
b 
to 
b 
b 
b 
b 
GO 
b 
Rank. 
These records are, of course, not numerous enough to 
justify any general conclusions, but they are interesting as 
showing that the percentile rank of healthy growing children 
may, during adolescence, vary within a range of four or five No. 34.] 
THE GROWTH OF CHILDREN. 
521 
per cent, on either side of an average value. How much 
wider the variation may be without passing the limits of 
health is a question for the determination of which a very 
large number of observations is necessary, and it is to the 
public schools that we must again look for the data which 
shall make it possible to give a definite answer to this and 
other questions relating to the phenomena of growth. Mean- 
while, the above-described variations during adolescence of 
the height and weight of children at the various percentile 
grades must be regarded as representing only in a general way 
the rate of growth of large and small children respectively. 
The importance of taking periodical measurements of 
pupils in the public schools has frequently been urged. In 
fact, this branch of anthropometry stands in such close rela- 
tion to physical training that it may be regarded as the 
test to which systems of physical training must be subjected 
in order to judge of their comparative efficiency. No teacher 
at the present day is satisfied to give instruction in any de- 
partment of learning without testing its results by periodical 
examinations of the pupils. In the same way the director of 
physical training can have no certainty that his efforts are 
well directed unless he can convince himself, by periodical 
determinations of height, weight, chest girth, strength, etc., 
that his pupils are making satisfactory progress in physical 
development. 
Here the question at once arises : What amount of prog- 
ress is to be regarded as satisfactory? and the importance 
of establishing a normal standard of development becomes 
apparent. A rough approximation to such a standard of 
development in height and weight for the pupils of the 
Boston public schools has been given in the above tables and 
curves. By their means it is possible to ascertain whether 
a given pupil retains his rank (relative to height and weight) 
among his comrades during the period of adolescence. It 
is obvious, however, that much more valuable results could 
be obtained if we wTere in possession of observations numer- 
ous enough to justify the construction of separate tables and 
curves for children of different nationalities; for it has been 
shown that children of American parentage in our public 522 
STATE BOARD OF HEALTH. 
[P. D. Ho. 34.] 
schools are, at nearly all ages, taller and heavier than those of 
other nationalities. It is also of great importance that some 
simple tests of strength should be applied to growing children 
in order to establish a standard of power as well as of size. 
When a system of annual physical measurements shall have 
been introduced into our public schools and recognized as of 
equal importance with the annual examinations in the vari- 
ous studies, we shall be in a position to formulate the laws 
of growth with much greater accuracy than is at present 
possible.