Transactions section: Effect of sapphire-crystal orientation on the wear of watt-hour-meter bearings

This paper describes the most recent of a series of studies on the life of watt-hour meter bearing materials. It covers an investigation of the effect of jewel crystalline axis orientation upon jewel wear. Lifetime stability of meter calibration is a function of bearing wear. A study of the wear (after several years´ service) of the sapphire jewel cups of meters in relation to crystalline orientation confirms predictions of another investigator; and a corroborative theory, based upon the physics of crystals, is presented.