WW1, Edison & Swan, Galvanometer, Q and I tester, No 21428, Dated 1918

*WW1, Edison & Swan, Galvanometer, Q and I tester, No 21428, Dated 1918*

8.4cm x 8.8cm x 5.5cm Wooden Box housing the testing meter 7cm diameter.

As communication systems developed, so did the equipment need to maintain these systems, this is one of those maintenance tools, an electrical strength and circuit tester, a ‘Galvanometer’. This particular one is very rare as it is dated to 1918 and was made by Edison & Swan likely for use by the military during WW1.

Edison and Swan United Electric Light Co. Ltd, the company that formed as a result of the 1883 merger of Thomas A. Edison's company and Joseph Swan's company. Joseph Swan of England, invented the light bulb at the same time Edison did. They sued each other, but settled and co-founded Edison and Swan.

A Galvanometer is an electromechanical measuring instrument to test the current’s existence, the current direction and its intensity on a field-telephone circuit and the circuit of a telegraphy system. When the Galvanometer is attached to the ‘system’ needing to be tested, it shows the presence of even the smallest of currents and shows this by moving of a magnetized needle on a dial, either clockwise or counter-clockwise depending on the currents direction. The "Q and I" stand for "Quantity and Intensity," 19th century electrical terms. The "Q" coil has a resistance of .2 ohms. The "I" coil has a resistance of 100 ohms. The "intensity" coil is used for localizing faults in lines using a series resistance. The "quantity" coil is used primarily for battery testing.

*Condition*
This is in great condition given its age and probable history. There is some rusting and discolouration to the metal work and some scratching to the woodwork but the glass is virtually unscratched. It is a great original find. Please see photographs as part of the condition report.

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