Lot 93

Edward Scrivener

Duo-in-Uno

An extremely rare precision watch with English experimental pivoted detent chronometer escapement and "DUO IN UNO" balance spring

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The "DUO IN UNO" balance spring allows a reduction in the height of a helical spring, thus saving space in the height of a pocket chronometer movement. In fact, it is a flat balance spring converting into a cylindrical spring. It was first introduced during the 1862 Great Exhibition in Kensington, London, at the Charles Frodsham stand.
According to Frodsham, it "almost certainly guarantees the most accurate performance in all positions with a perfectly poised balance" (exhibition catalogue, p. 22).
This type of balance spring was supposedly invented by Mr. Mairet of Baker Street and presented during the 1862 exhibition by Charles Frodsham and Mr. McLennan; However the design had already been used by Arthur Paul Walsh since circa 1860.

English watchmaker, chronometer maker and jeweller Edward Scrivener worked in London from around 1848 to 1880 at 19 Cockspur Street, Pall Mall.