Early 'Heliochron' Pantochronometer trial frame While one lyden jar is

While one lyden jar is slightly compromised

This highly sensitive instrument was often used in photometry and hygroscopy

Early 20th Century (circa 1920)

Dimensions: 8

Early 'Heliochron' Pantochronometer trial frame While one lyden jar isA Rare early 19th century Pantochronometer hand engraved 'HELIOCHRON' on lid. Complete original. Dome cased brass sundial compass with floating paper face and fixed brass gnomon. Pantochronometers were first developed in the late 1700's, and widely popularized in 1820 by Samuel Porter. A fine, functional, scarce, and early example. Circa 1830. Diameter: 4. 5 cm. Height: 3 cm. Weight: 1. 7 oz.