A German 400-day torsion timepiece with rare mercury compensated balance

A German 400-day torsion timepiece with rare mercury compensated balance, unsigned, early 20th century
The movement with five-wheel train and deadbeat escapement regulated by rotating balance incorporating opposing angled mercury capsules flanking a lyre-shaped upright over cylindrical adjustable timing weights suspended beneath the movement on a long torsion suspension spring, the backplate with pallet viewing apertures and stamped with serial number 133513 to lower right hand corner, the circular cream Arabic numeral enamel dial with blued steel spade hands set within a bead cast bezel beneath shaped crest incorporating three turned finials to the movement frontplate, the whole raised on twin column uprights over a moulded circular brass base incorporating a channel to take the glass dome cover, 28cm (11ins) high overall.