Some previous work by one of the authors with wires of an alloy of platinum-iridium, portions of which work were published in these Proceedings, indicated that when the wires were used as suspensions for torsion pendulums, the relations between the period of vibration and the amplitude were exceedingly complicated. The effect of drawing these wires was dealt with in another paper. In all these papers referred to, the statement was made that similar tests should be applied to some of the more common wires in the hope of finding similar, even though smaller effects. Through press of work these experiments have been deferred until the present year. This particular paper will deal with but one feature of the work, namely, the effect of drawing on the elastic nature of phosphor bronze wires. The writers are indebted to the American Electrical Works, of Phillipsdale, Rhode Island, for kindly furnishing them with specimens of the wires
