The grease which is allowed to remain in the case for a long time has these small particles in contact with the balls and runways, and is sure to wear more than new grease. Plumbago in the grease will be of great service in aiding to coat the balls with a good surface. These remarks as to the removal of old grease is desirable wherever ball bearings are employed. The gears in the case should also be examined to ascertain whether the edges are chipped, or what the wearing action is. THE DIFFERENTIAL.--This also requires care, but carelessness in lubrication is the only feature lacking in so many cars, and it is the most frequent shortcoming with the novice. The differential seems to be the one part of a car which, in his estimation, requires no attention. If there is any play between the pinions and the studs, it should be promptly taken up. This can be done, usually, by inserting washers of proper thickness behind the gears, in cases where no provision has been made for adjustment. UNIVERSAL JOINTS.--The wearing points of the universal are in the pins. These are susceptible of a great deal of wearing down before the facts will make themselves known in the operation of the machine, hence the necessity of examining this part when you are on an inspecting tour. STEERING GEAR.--The steering gear should be taken apart, and every working portion cleaned. The ball-bearings may be worn, or the joint out of adjustment, to which the stiffness of the turning movement is likely due. WORM AND WORM WHEEL.--When wear begins between the worm and worm wheel, there is a looseness apparent, so that the steering wheel must, sometimes make a considerable part of a turn before the effect will be apparent on the wheels. This should be taken up so the wheels will be in full mesh. The rod from the sector lever to the pedal should be taken off and examined, to see whether or not it is bent, and properly adjusted as to length. BATTERIES.--These need inspection and attention more frequently than any other part of the mechanism. It is often the case that a battery, particularly storage batteries, will show strong amperage, and suddenly give out entirely. THE VIBRATOR.--When such is the case it may be attributable to the contact point of the vibrator having too heavy an adjustment, and as a result, it will be less responsive, or be slow in its action. This causes corrosion of the contact points. In action the vibrator should give a high-pitched buzzing sound, which produces a hotter spark, and also preserves the life of the battery. THE ELECTROLYTE.--The electrolyte in the storage battery may need refilling. The old liquid should be removed, the case thoroughly washed out with distilled water, and refilled, using about three quarters of the old liquid, and the residue soft fresh water.