APPARATUS. 351 



closed by a moulded cap (Fig. 46, F); and a band 

 moulded to the cap gives the means of fastening 

 the tube to the finger. These tubes are mounted 

 on a " foundation " of sheet red rubber, which is 

 fastened round the hand like a glove (see Fig. 47). 

 The arrangement represented in Fig. 48, a and b, 

 is convenient in the case of adults, in whom the 

 thickness of the finger makes a considerable drag 

 upon the upper surface of the tube during flexion 

 of the finger. It consists of a pair of moulded 

 caps mounted on a ring back to back : the septum 

 between the two is divided halfway down, and the 

 lower portion is pierced, allowing air to pass from 



Fig. 48. Junctions for Motor Tubes. 



one cap to the other. The band is fastened to the 

 middle of a phalanx, and, the finger-tube being cut 

 at this point, the divided ends are inserted one in 

 each cap. The whole is thus rendered air-tight, 

 and the tension of the upper surface of the tube 

 during flexion of the finger is thus relieved. 



The recording tambours mounted in a frame (see 

 Fig. 49) give tracings upon a revolving cylinder, 

 showing the frequency and coincidence of the 



