iqiq] 



HENDRICKS— TORSION 



427 



by fine wires and are labeled A, B, C, D. The yoke {Yk, fig. 3) is 

 a curved piece of hard wood (about 5X1 X0.6 cm.) and has fitted 



n^./ 



Fige. 



n^.z 



h k 



F/a. '4- a 



Figs. 1-4 



over it a piece of "tin" (/), which is approximately U-shaped, with 

 the "base'' of the U back of the yoke. Its position on the yoke 

 can be regulated by means of a peg on the small screw is), only a 



