1906-7.] Variation of Young’s Modulus under Electric Current. 345 
grooved piece of wood at K, through the tube and over the wheel L to a 
pan in which the weights were placed. The wheel was mounted on anti- 
friction rollers. A pasteboard tube protected the portion of the wire 
between the glass tube and the wheel from currents of air. The wires 
for the current and for measuring the resistance were attached near 
G and H. 
The plan of connections for measuring the resistance is given in fig. 2 , 
the fall of potential method being used. The portion EF of the wire 
