An extremely rare pre balance spring English silver pair case Astronomical verge watch with year calendar indicating date, month, sign of the Zodiac and time of sunrise with further indications for day of the week, and the age and aspect of the moon, signed “Henricus Harpur / Londini”, circa 1670, 55 mm diam

movement

The round pre balance spring movement has egyptian pillars, a verge escapement with four wheel train, fusee with gut line and regulation by means of a [restored] tangent screw set up to the mainspring arbor. The floral pierced cock is secured to the backplate by means of a screw.