Bow—The ring of a watch case to which the guard or chain is attached; also known as "pendant bow."
BOW AND BUTTON
Box Chronometer—A marine chronometer.
Boxing-In—Fitting the watch movement in its case; applied chiefly to the encasing of stem-winding movements.
Bréquet, Abraham Louis—A celebrated Swiss mechanician and watchmaker born at Neufchatel in 1747. He made several improvements in watches, the most notable being the Bréquet hairspring still in use in the best watches. He died in 1823.
BRÉQUET SPRING