The jewel hole in the balance of a Geneva watch is held in position by the thin edge of its setting being burnished over the edge of the jewel. In fitting a new jewel hole, the old one must be pushed out by a flat-pointed peg, and the edge of the setting raised by very carefully running the smooth point of a centre-punch round it. After fitting the new hole, which should go tightly into its recess, the thin edge must be once more burnished over the edge of the stone by running the centre-punch point round it, using a little oil as a lubricant.