PEDAGOGICAL METHODS 73
psychology may be reduced to one; namely, carefully recorded observation of the subject."
Treating of children, another factor must necessarily intervene: the study of the development. Here too, I retained the same general criterion, but without clinging to any dogma about the activity of the child according to age.
In regard to physical development, my first thought was given to the regulating of anthropometric observations, and to the selection of the most important observations to be made.
I designed an anthropometer provided with the metric scale, varying between .50 metre and 1.50 metres. A small stool, 30 centimetres high, could be placed upon the floor of the anthropometer for measurements taken in a sitting position. I now advise making the anthropometer with a platform on either side of the pole bearing the scale, so that on one side the total stature can be measured, and on the other the height of the body when seated. In the second case, the zero is indicated at 30 centimetres; that is, it corresponds to the seat of the stool, which is fixed. The indicators on the vertical post are independent one of the other and this makes it possible to measure two children at the same time. In this way the inconvenience and waste of time caused by having to move the seat about, is obviated, and also the trouble of having to calculate the difference in the metric scale.
Having thus facilitated the technique of the researches, I decided to take the measurements of the children's stature, seated and standing, every month, and in order to have these regulated as exactly as possible in their re-