396 WORK OF THE PHYSIOLOGICAL STATION AT PARIS. 



ments of their own wings, together with the reactions which such 

 movements produced upon their own bodies. 



An artist's studio, No. 14 rue de I'Ancienne Comedie, furnished me 

 the large room necessary for my purpose. This studio, 15 meters long 

 by V2 wide and S high, was well lighted. It was easy to set up within 

 it the workbench of a mechanic, cages for animals, and glass cases 

 for the instruments, already so numerous, required for physiological 

 researches. In this way, an old theater which had accommodated the 

 ConnMlio Fran^aise in its early days, and was afterwards the studio in 

 which Horace Vernet painted his great heroic pictures, became in turn 

 a shelter for science, and was the first laboratory established bypriv^ate 

 enterprise for physiological experimentation. 



Many advantages were already combined in this first establishment. 

 They were certainly superior to those which I found later at the College 

 of Fiance when I entered it as professor. Much time is saved if the 

 construction of the instruments, together with the incessant niodifica- 

 tions of them re(iuired by this kind of experimentation, can be super- 

 vised in the same apartment in which the experiments themselves are 

 conducted. 



With carefully tamed buzzards, with ]>igeons, and with ducks, I 

 succeeded in registering the moA'ements of tlight, the frequency and 

 character of the wing strokes, the contraction of the muscles, and tlie 

 reactions produced upon the body of the bird. 



This study conducted me to that of the resistance of the air, which 

 made it necessary to construct a whirling table meters in diameter, in 

 order to determine the pressure of air on different surfaces for dittereut 

 velocities of rotation. 



This apparatus, also supplied with special registers, gives us an 

 op])ortunity of analyzing the movements of walking in man, and was 

 used in the beautiful experiments of my pupil and lamented friend, 

 (t. Carlet. 



As might have been expected, the space was soon found insufficient 

 for studying the locomotion of man. On a circular path 20 meters at 

 most in diameter it was impossible to walk otherwise than slowly, 

 incessantly ham]>ered by the curve of the circle. Open roads were 

 necessary for the study of walking ami running, and horizontal or vari- 

 ousl}' inclined footways were required for the determination, bj^ means 

 of the portable odograph, of the influences that cause variations in the 

 cadence and length of steps. I often had to go far in order to find all 

 the necessary conditions. 



Later, attempting to determine the best means of utilizing the mus- 

 cular force of man and animals, I had to compare the amount of work 

 expended in the traction of carriages, both with rigid and slightly elas- 

 tic traces, and upon different kinds of ground. In the neighborhood of 

 the grounds of the Luxembourg there were certain avenues paved in 

 different ways. I here experimented with carriages drawn at ditterent 



