Voltmeter teaching aid by W & J George Ltd, Birmingham, no 25938A. A Voltmeter is a measuring instrument for measuring the voltage between two points in an electric circuit. This fine voltmeter is fitted in mahogany wood frame and base. Also inscribed on the front of the base: 'PHY 1', probably signifying the use of this instrument in the physics laboratory. Dimensions in inches (W x H x D): 7 x 6.5 x 3.1.