Remove the barrel bar with its several attachments; also the third wheel, and, if necessary, test the unrighting of the centre wheel by passing a round broach or taper arbor through it, and setting the plate in rotation about this axis, holding a card near the edge while doing so. This will indicate at once whether the axis of the wheel is at right angles to the plate. If a marked deviation is detected, or the holes are found to be too large, they must be re-bushed and uprighted. If the error is but slight, the axes may be set vertical by bending the steady-pins a little, in doing which proceed as follows: - Set the bar in its place alone, the screws a little unscrewed; rest the ride of the bar opposite to that towards which it is to be bent against a piece of brass held in the vice, and strike the farther edge of the plate one or two sharp blows with a small wooden mallet. Experience alone can teach the workman to proportion the blow so as to obtain a given amount of deviation, and must enable him to ascertain whether it is desirable or not to pass a broach through the steady-pin holes before operating as above explained.
The centre pivots must project beyond the holes in the plate and bar. A circular recess is turned round the outer end of each of these holes so as to form reservoirs for oil. Owing to the neglect of these simple precautions, many watches, especially those that are thin, come back for repair with their centre pivots in a bad state, because the oil could not be applied in sufficient quantity, and has been drawn away by the cannon pinion or the steel shield. If the watch has a seconds hand, ascertain by means of the calliper that its wheel is upright. Finally, examine each jewel to see that it is neither cracked nor rough at the edges of the hole.
The side spring, which must not be too strong, should reach with certainty to the bottom of the spaces between the teeth of the ratchet, and this latter should be held steadily in position by the cap. The barrel is made straight and true on its axis, the arbor having been previously put in order if required. It is a good plan after making the extensive repairs here spoken of to again test the barrel and centre-pinion depth, either by touch or by drilling a hole for observation. The screw of the star wheel must not project within the cover nor rub against the dial; it must be reduced if either case presents itself.
The action of the stopwork must be well assured, especially when the actual stop occurs. It is a good plan to, as it were, "round-up" the star wheel and finger-piece, with an emery stick, supporting them on arbors. There must be no possibility of friction between the finger and the bottom of its sink. To test the stopwork, take up the winding square of an arbor, with the barrel, etc, in position, in a pair of sliding tongs or a Birch's key; hold the tongs between the last 3 fingers and the palm of the left hand, the first finger and thumb being applied to the circumference of the barrel so as to rotate it, first in one direction and then in the other. During this movement, take a pegwood point in the right hand, and try to turn the star wheel against the direction in which it would be impelled by the finger. The tooth that is just going to engage with the finger will thus be caused to take up the worst possible position for being turned, and thus, if the action proves to be satisfactory for each tooth, you may rest content as to the future; providing, of course, that the engagement takes place square, and there is no tendency to cause distortion of the metal.
By holding the sliding tongs in a vice, both hands can be kept at liberty.
It facilitates the work to secure order in taking to pieces and cleaning, preventing the screws from being mixed, etc. It is a good practice to prepare beforehand one or more boards, in which grooves and holes are made in positions to correspond with those of the several pieces on the plate of the watch, as indicated by Fig. 227. The round holes receive the cock and bar screws, which may be cleaned while the other parts arc in the benzine solution. (Two holes are shown side by side for each bar and cock, so that the same plate will serve for a large and small watch.) The oval or circular hollows at a and round b receive the cap screws, and b the shield; c holds the screws of the side spring and star wheel, and the finger-piece pin; d is for the screws of the top endstone, and e for those of the bottom endstone, etc.
Very conveniently divided deal boxes, for holding the several parts of a watch when taken to pieces, are in general use by watchmakers. They are of foreign manufacture, and measure about 6 in. by 4, and 1 in. in depth, thus being large enough to contain all the parts of any ordinary watch. Every young workman will find the advantage of noting on a paper, bearing the number of the watch, the successive operations that have to be done, striking them out one by one as the work progresses.
Whatever the system of cleaning adopted, it is essential that it be concluded by passing a pegwood point into each of the holes. Brilliancy is given to the surfaces of cleaned pieces by passing a carefully kept fine brush over them. A brush that is greasy can only be cleaned by soap and water, and a new brush is prepared for use by passing an inclined cutting edge over the ends of its bristles so as to taper them off to fine points, and to remove knots due to hard parts or to bristles becoming united. This preliminary treatment is completed by charging the brush with French chalk, and rubbing it vigorously on a dry crust of bread until the brush can be passed over a gilded surface without scratching it. The bristles are maintained in good condition by the same treatment. Billiard chalk is very effective for this purpose. The greater number of cavities there are in a crust the better it will act. Groat bread seems to be preferable to that made from wheat, because the latter contains greasy particles which prevent the brush from being kept thoroughly clean.