relatively short space of time, generally as a result of excessive abuse. A bad bearing can usually be detected by the presence of vibration and noise long before complete failure can cause damage to the machine. REMOVAL OF BEARINGS In removing ball bearings from the shaft, pressure should be applied against the inner race, otherwise the bearirg may be seriously damaged. Bearings may be removed by pressing out the shaft in an arbor press, or by means of bearing oullers. ilways press or pull straight and square to avoid scoring the shaft or damaging the bearings. CARE OF WINDINGS Machines and spare coils should be stored in a clean, dry place until they are installed. Heat should be supplied to prevent "sweating" due to sudden temperature changes. Machines that have been subjected to moist atmosphere in transit, have been idle for some time without heat, or have become wet by accident, should be thoroughly dried out before being placed in service. Heating may be accomplished by passing current at low voltage through the windings, or by the use of electric heaters or steam pipes. Proper temperature can be maintained during long periodsof idleness by placing a small heater inside the machine end covering the machine with a tarpaulin. JRYING OF WINDINGS orying ovt can be most effectively accomplished by passing current through the windings. The current should be a mere fraction of full- load current, and the voltage should be low enough to be safe for the winding in its moist condition. The drying out heat may also be applied externally by the use of heating units placed around or in the machine. This method is most effective under a temporary housing of sheet metal 3-51