German silver astronomical verge with calendar Circa 1640

Extremely rare Puritan pre balance spring astronomical watch by Johann Sayller
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An extremely rare German silver Puritan pre balance spring astronomical verge watch with calendar, circa 1640. Polished oval case, turnable pendant, seven piece hinge. Firegilt oval full plate brass movement, keywind, applied floral silver decorations, large barrel with fusee and early chain, baluster movement pillars, verge escapement, ratchet wheel set up with blued steel spring, two armed steel balance without balance spring, florally engraved and pierced silver balance cock, blued steel arm for hog’s bristle regulator marked on a dotted scale. Firegilt brass dial, applied silver chapter ring with engraved and inlaid radial Roman hours, outer ring with twelve touch pieces for night reading, silver date ring, inner gilt brass lunar calendar ring, central silver disc with engraved aspectarium and aperture for moon phase, single blued steel tulip hand and date pointer, aperture above 12 for months and below 6 for weekdays in German. Movement signed.
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Dimesions: 47 x 37 mm
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Weight: 106 g
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Signed: Johann Sayller Ulm
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