For Melde's and other experiments. A steel rod is clamped
near one end through two 4mm terminals. The rod passes through
a small solenoid and between the poles of a magnet. Adjustable
contact points fitted through a second pair of terminals make
alternating connection with an adjustable contact on the rod.
The rod has a small hole at one end for the attachment of
thread which passes over a bench mounting pulley and supports
a scale pan. For 2V a.c. Supplies. With pulley and clamp,
scale pan and instructions.