In the first section the reader is made familiar with the nature of the problem to be investigated, the material used for the investigation and the sort of data obtained therefrom. In order to learn the relation of breathing capacity (vital capacity) and grip strength to other physical and mental measurements and to health, it was necessary to devise apparatus which would be suitable for use with the 169 children, aged 2½ to 6½ years, available for this study in the Iowa Child Welfare Research Station.
The first chapters in sections II and III review the previous work done on breathing capacity and grip strength. The next chapters describe the devising of apparatus–spirometer and dynamometer–and the working out and checking of the reliability of technics. The remainder of each of these sections is taken up with the presentation and discussion of results with adequate charts and tables. Formulas are given