Variable condenser for use in measuring circuits where dielectric loss must be held low. It is useful in bridge assemblies for balancing out residual capacitances or neutralizing small inductances. It was mounted in mahogany case completely shielded (now destroyed). Binding posts and dial, with 0 to 100 divisions were mounted on a polished black top. Probably model C (20 to 1000 μF) because it is giving values at each 10 divisions.
Manufacturer: CENCO, No 83515