M. MAREY has again applied his chronophotographic methods in making an analysis of the movements of athletes while exercising their strength in different ways. His delightful experiments, which have been but little repeated by others, are described in detail in “Le Mouvement” (par E. Marey. Paris: 1894. Translated into English by E. Pritchard. London: Heinemann, 1895). The methods are, for the most part, so simple, and the results so valuable, that they should prove themselves attractive to the student of those subjects in which movement of any kind is to be measured. In 1900, during the exhibition in Paris, there was a large gymnastic meeting and athletic sports. The administration of the exhibition nominated a commission of physiology and hygiene, for the purpose of following the meetings and gathering front that unique assembly of tite best athletes in the world the information which it afforded. Its object was to determine, from a physiological point of view, the action of the various forms of exertion on the organic functions, viz, the respiration, the circulation of the blood, the digestion and, finally, the general health. The commission also studied different kinds of sports with a view to understand their mechanical details and discover the secret of the superiority of certain athletes. The chronophotographic method gives a series of instantaneous photographs, on a long ribbon which is unwound; the number of pictures varies from fifteen to twenty or more per second. By this means the phases of a movement are perfectly represented. Figures so produced on a band being somewhat difficult to compare with one another, it was found to be more convenient to arrange them, as in Fig. 3, in three columns, the sqccession of pictures in each column reading from top to bottom, commencing on the left. The subject is that of “putting the weight ” by the American athlete, Sheldon. The weight used by all competitors was 7.25 kilogrammes, = 15.95 lb., or the 16 lb. shot used in English athletic sports, and the distance covered was 14.02m. = 45.98 feet. Fig. 3 shows the athlete at the moment of his take-off from the right leg. At the end of his jump, and at the moment when the left foot touches the ground, he brings his right arm into action, which moves the shot upwards and forwards, giving it the greatest velocity possible.