January 7, 1892] 



NA rURE 



229 



In another illustration we have an interesting set of atti- 

 tu les assumed by a running man dressed in this costume 



Fig. 2— Man dressed in black, an i consequently invisible when passing 

 before a dark background. The white lines which are shown on his 

 arms, legs, and on the so!e of one foot are the only parts the successive 

 phases of which can be recorded. 



(Fig. 3). The lines in the figure indicate the sequence 

 of positions m which the above-mentioned distinguishing 



being photographed in a given time is very largely in- 

 creased, while the overlapping is only slightly apparent. 



Another case is that shown in Fig. 4, which represents 

 a man jumping. The several phases of movement are 

 here also well discernible, and the images were recorded 

 at the rate of twenty-five per second. 



Although the method employed above suited admirably 

 for such purposes as we have mentioned, yet Prof. Marey 

 found that he could not use it without modification for all 

 the cases to which he wished to apply it. The apparatus 

 which he then constructed, and of which a complete de- 

 tailed accountjs given in his article, is shown in Fig. 5, and 



Fig. 3. — Images of a runner, showing the 

 attitudes of the principal members, 

 plate. 



white marks which represent the 

 Chronophotography on a fixed 



differs in many particulars from the former one, the chief 

 characteristic about it being that films are employed 

 which are capable of rapid lateral movement. By means 

 of this moving film it is possible to obtain, in a very short 

 space of time, a large number of separate pictures, for, 

 during each exposure, a new part of the film is brought 

 opposite the lens of the camera, held there, and then 

 slipped along. The apparatus itself is of a most ingenious 

 construction, and the three most important parts consist 

 of a driver, a clamper, and an elastic arm. 



In the figure, L represents the driver, and it is due to 

 its action that the motion of the paper is produced ; it 

 consists of a wooden cylinder, the surface of which is 

 covered with india-rubber, and round which the band of 



Fig. 4. -Analys.s of the phases of a running high jump. Taken on a fixed plate (twenty-five images pers:c5nd). 



marks are found at each exposure; and the resulting j paper passes when made to travel from one bobbin to the 

 diagram also shows that the number of images capable of other. 



NO. I I 58, VOL. 45] 



