_In no case should the contiguous surfaces of the hole and cap jewel be both made flat_; as, when their planes are vertical, the oil will be drawn downwards by gravitation (18), there being no counteracting force (22) to keep the oil in place. The author has remedied this defect, in many instances, by cutting a groove around the jewel, leaving only enough metal near the jewel to hold it, and enough near the edge of the setting to rest solidly against the other setting. In some watches, particularly those of Swiss make, the jewel bezels--both cap and hole--are brought well up around the jewel, while _a groove is cut around the jewel bezel_. In this instance the oil may be made to cover the whole inside surface of both jewels, as the groove will prevent the oil from flowing away to parts where it is not required. The reprehensible practice of replacing a broken cap jewel by cutting away the bezel and placing the new jewel in loosely, cannot be too severely condemned. The new cheap foreign-made watches contain this objectionable feature in many instances. Where the jewels are in settings, sharp instruments, as tweezers, etc., should never be used to push the settings in place; as the projections produced in this manner would not only injure the appearance of the settings, but would prevent their close contact. Thoroughly _clean_, well-finished jewel pushers are indispensable; as even pegwood is liable to leave fibres at least. The shape of the oiler is a matter of some importance; as with a poorly-made oiler it is next to impossible to do work satisfactorily. The tip is preferably of gold, tapering towards the end to about the size of a second's hand pivot of an eighteen size American movement; but at the end it should be about three times as wide and flat. A nickel fastened to the end of a lead-pencil will give the idea approximately. This large end will cause the oil to remain where it may be readily applied to the bearing surface, instead of flowing back on the oiler towards the handle, as it would (22, 7) if the point were tapering. ~59. The Stem Winding Mechanism~ should be thoroughly well made, always keeping in view that the laws of capillary attraction must be complied with. Wherever an angle can be formed, with its apex pointing towards the place where the oil is required to remain, it should be done. A very good lubricant for stem wind parts is found in stearine, from which the animal oils are expressed at cold temperatures, as it is very thickly fluid at ordinary temperatures; while an _excellent_ lubricant for this purpose is paraffine--not the wax nor the oil, but that white, soft substance from which both are obtained (13 & 73). Stearine and paraffine both possess great viscosity; and, though the fluid friction is increased by their use, the solid friction is diminished. Then, too, _the tendency to spread is very much less_.