Nuremberg Eggs—Watches made in Nuremberg in the shape of eggs. If not the first watches at least very early examples.
Obelisk—A square shaft with a pyramidal top. The ancient Egyptian obelisks are thought to have served as gnomons.
Ogive—A pointed arch—of the architectural type known as Gothic.
Oil Sink—The cavity around the pivot hole in watch and clock plates, designed to hold a small particle of oil in contact with the pivot.
Ormolu—Gilt or bronzed metallic ware, or a fine bronze which has the appearance of being gilded. Used for ornamenting the cases of fine old clocks.
Orologe—An obsolete form of horologe. See [Horologe].
Orologiers—An obsolete form of horologers, a term not now in use but signifying men who constructed time-pieces.