Description
A very large sturdy two-armed sector by “Tavernier Gravet, 19 rue Mayet Paris.”
Dimension: 42.8 x 5.8 x 0.7 cm (16 ¾ x 2 ¼ x 1/3 “)
Case: 45.7 x 11.6 x 3 cm (18 x 4 ½ x 1 ¼ “)
Weight: 2 Kg (incl. case)
Division: front 10-600 (Line of Chords) ; backside 10-170 (Line of Equal Parts)
This sector represents a late witness of a widespread instrument introduced by Galileo. Popular during two centuries, “sectors continued to be used as a calculating instruments until the mid-nineteenth century when logaritmic tables came into general use; after 1880 the availability of engineers’ slide rules further eroded their value …. From 1850 onwards a sector continued to be provided in cases of instruments as a symbolic or traditional calculating instrument, but it ceased to be used after 1900” (Hambly).
Please note: bad reflections are only given by illumination.
Wooden sector of normal size (15 cm, 6”) for comparison only.
Tavernier – Gravet (working from 1876-) was a French instrument maker working in Paris in the last quarter of 19th century (39 rue de Babylone et 19 rue Mayet) (Marcelin, ad vocem).
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Dealer information
Alpha et Omega
Alpha Et Omega
Alpha et Omega is a recently established firm, based in Milan, Italy. We specialise in antique Scientific Instruments and rare Books to supply collections worldwide. Focus is given to optical and time-related instruments, especially before the Industrial Revolution but we are also interested in rare-to-find scientific and natural items and wunderkammer objects. Alpha et Omega also deals in rare books related to Early Science and Scientific Instruments. Please feel free to contact us for individual requests or desiderata.