Eight-Day Marine Chronometer

A rare eight-day marine chronometer in its original marquetry-inlaid rosewood and mahogany box, with gimbals. Massive gilt reverse-fusee movement with fully capped 1/2-seconds beating Earnshaw-type spring-detent chronometer escapement, blued helical hairspring and bimetallic Z-balance. The inner box contains a label from Max Kuner Co, chronometer maker and agent for US Govt charts in Seattle.

Most chronometers are of thirty-hour (one-day) duration. The longer the duration, the more complex the mechanism to maintain accuracy over the longer duration.