19th Century Equinoctial Pocket Sundial in Original Case, signed V. Simalvico

19th Century Equinoctial Pocket Sundial in Original Case, signed V. Simalvico

A Fine and Rare Early 19th Century Equinoctial Pocket Sundial in Original Case, Signed V. Simalvico, London.

The gilt brass circular base has a glazed silver compass rose and blued steel hands indicating North and South (N and S). The base plate, resting on the bottom of the compass, has a hinged silvered chapter ring with a collapsible gnomon. There is a silver sectorial scale (0-60°) to set the local latitude by moving the chapter ring up or down. The time is indicated by the collapsible shadow of the gnomon on the chapter ring.

The sundial retains the original leather travelling case and opens on the original hinge by releasing the hook and eyes to the left and right of the case. To the base of the inside of the case is a paper label that relates to the equation of time, which relates solar time to mean time (being the time we read on a clock). The difference between solar time and real-time varies from +16 to -15 minutes.

The Maker
Vincent Simalvico. Brother of Joseph. Both are famous instrument makers. Worked 14 Charles St., Hatton Garden, London. 1833-1860. optician, barometers, thermometers and chronometers.

It should be noted that English pocket sundials from the period are extremely rare and this is a superb and original example in fantastic condition.

It should be noted that fine English pocket sundials are extremely rare and from research this is the only example by the maker.