PRECISION IN PHYSICAL TRAINING. 473 



on a vertical plane. The measuring-tape gives false indications 

 of the dimensions of the thorax, for its measurements are influ- 

 enced by the muscular protuberances. We have substituted for 

 gross measurements of the circumference of the thorax those of 

 diameters obtained with compasses and thoracometers specially- 

 constructed to give the amplification of the framework of the 

 chest in respiration. With these exact means, and the assistance 

 of physicians who are all interested in these questions, we hope 

 to organize in schools a series of measurements that will cast 

 light on many obscure points. Data are wanting for the defini- 

 tion of the characteristic differences in the form of different sub- 

 jects whose movements have been accommodated to a special and 

 well-defined profession ; and those data in particular are wanting 

 with which to establish the laws of the development of children 

 according as they have or have not been subjected to physical 

 exercise under various conditions. We have begun investiga- 

 tions on this point at the College Sainte-Barbe, with the aid of 

 M. Rey, and at the school of Joinville le Pont, with that of M. 

 Roblot. We have found that with growing children the increase 

 of the respiratory capacity is parallel with that of the weight, 

 and has no fixed relation with the stature ; and we have shown 

 that the ratio of the respiratory capacity to the weight increases 

 regularly under training. We find also that the absolute dimen- 

 sions of the thorax do not increase among adults, but that the 

 extent of the movement of the ribs is related to the respiratory 

 capacity. It is, for the same subject, parallel with the quantity 

 of air breathed in. M. Marey showed, some time ago, that the 

 thoracic movements of subjects under exercise are amplified, 

 while their frequency diminishes. Respiration becomes fuller 

 and remains so during rest or after intense exercise. By collat- 

 ing observations bearing on this point, we shall be able to con- 

 stitute a kind .of experimental physiology of exercise, and shall 

 thus have the best and only means of pronouncing without pre- 

 possession upon the value, as to the general development of the 

 body, of different methods of education. 



We now proceed to examine the tendencies of exercise in view 

 of the economical utilization of muscular strength. The third 

 essential point in physical education consists in establishing the 

 rules that permit the useful and economical employment of mus- 

 cular force in the various conditions of locomotion, in the man- 

 agement of tools and arms, and in carrying burdens. This is one 

 of the most delicate chapters of animal mechanics. It is the one 

 that is really entitled to be designated the education of the move- 

 ments, for the educator plays the greatest part in it, and his 

 action is indisputable. When one has devoted himself for a long 

 time to practical exercises of the body, especially to varied exer- 



