Georg Friedrich Brander (*1713;†1783), Augsburg.

Lambert's perspective sector, unsigned, ca. 1780.

The perspective sector, in its original cardboard slip-case, was designed by the 18th-century Swiss mathematician, physicist and astronomer Johann Heinrich Lambert (1728–1777). It was created as a mathematical aid for practitioners of perspective, such as draughtsmen, architects and artists. The scales appear to have been taken from the plate with illustration of the Perspectiv-Proportionalzirkel in Lambert's treatise on the subject, published in Augsburg in 1772 [9].

In Augsburg in 1780, the prominent German instrument maker Georg Friedrich Brander published a separate treatise on Lambert's sector and was known to have made examples of it for sale to the public [6]. One side has scales that facilitate the drawing of an image in perspective. The other side is marked with five pairs of lines, labelled Lin. Arithm., Tang., Sectant., Sinus and Ellipt. A similar perspective sector is featured as object of the month at the Kremsmünster Observatory Museum [2]. Paper on boxwood.243x72x9mm.

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NOTES / REFERENCES

[1] BRACHNER, Alto; G.F. Brander 1713-1783 Wissenschaftliche Instrumente aus seiner Werkstatt, Deutches Museum, Munchen, 1983.

[2] Perspektiv-Proportionalzirkel von Georg Friedrich Brander: Objekt des Monats aus dem Museum der Sternwarte Kremsmünster, Juli 2004.

[3] STECK, Max; Johann Heinrich Lambert, Schriften zur Perspektive, Berlin, 1943.

[4] SCHNEIDER, Ivo; Der Proportionalzirkel: ein Universelles Analogrecheninstrument der Vergangenheit, München‎ 1970.

[5] SCHEFFELT, Michael; Instrumentum proportionum, oder Unterricht vom Proportional-Zirkel, Ulm 1697.

[6] BRANDER, Georg Friedrich; Beschreibung und Gebrauch eines geometrischen Instruments in Gestalt eines Proportionalzirkels, Augsburg 1780.

[7] GUNTER, Edmund; The Description and Use of the Sector, London, 1624. 
[8] GOLDMAN, Nikolaus; Tractatus de usu proportionatorii sive circini proportionalis, Leiden 1656. 

[9] LAMBERT, Johann Heinrich; Kurzgefaßte Regeln zu perspectivischen Zeichnungen vermittelst eines zu deren Ausübung so wie auch zu geometrischen Zeichnungen eingerichteten Proportionalzirkels, Augsburg 1772. 

[10] LAMBERT, Johann Heinrich; Jeden Perspektivischen Aufriß von freien Stücken und ohne Grundriß zu verfertigen, Zürich 1759.

[11] An illustrated French translation of the above. LAMBERT, Jean-Henri; La perspective affranchie de l'embarras du plan géometral, Zuric 1759.

[12] ANDERSEN, Kirsti; The Geometry of an Art, New York 2007.

[13] ERWIN TOMASH, MICHAEL R. WILLIAMS, The Sector: its history, scales, and uses.  

[14] Daniel Huber; Johann Heinrich Lambert: nach seinem Leben und Wirken, 1829 [Google Books]