Cross-Beat Escapement

Cross-Beat Escapement. Jerg Ernst, Augsburg, first quarter of the 17th century. Fine and very rare oval smoked crystal, gilt silver mounted, large octagonal pre-balance spring pendant watch with cross-beat escapement. Two-body, hinged, back and band formed from two single pieces of faceted smoked crystal, mask pendant and finial. Gilt silver, champlevé radial Roman numerals, inner quarter divisions, champlevé center with polychrome flowers and a bird, the whole on gilt pierced and engraved domed plate. Steel tulip hands. 51 x 41 mm, oval, full plate, baluster pillars, fusee and gut, short train, cross-beat verge escapement, two foliots geared together and terminated with silver winged cherub masks, small irregular cock with high neck, striking works removed, elaborate mainspring set-up ratchet click. Signed on the back plate.Dim. 81 x 50 mm. Notes Provenance: Belin Collection. Georg (Jerg) Ernst, Augsburg. Became Free 28.12.1621, died after 1634. Among his known works are: a table clock in the Kunsthistorisches Museum in Vienna, No. 322; an octagonal rock crystal pendant watch, circa 1630 (formerly in the Slg. Pleissner collection); a four-sided table clock, circa 1600/1650. Cross-Beat Escapement. The verge escapement was not sufficiently accurate to fill the needs of scientists and astronomers, especially before the invention of the balance spring. This was why Jost Bürgi, a celebrated clockmaker of Wilhelm IV of Hesse, invented a new escapement around 1580. It had les