Inventory no. 50738 - Former Display Label
German SECTOR
1742
Brass. Signed, and dated, "J. L. Koch. fecit. Berolini. 1.7.4.2."
With scales marked "Tangent.", "Reduc. Plan. et. Corp. regul.", "Tetrag.", "Sub. Ang. Polÿg", "Arithm.", "Geomet.", "Inscriptio.", "Corp sphæ.", "Fortificat.", "Metallica.", "Circ. divid.", "Chord ar.", "Cubica.", "Rectæ", "Divisia", "Circumf. Extrema. ac. media. ratione. secandi." and "Diam.".
J. L. Koch was perhaps related to the instrument-makers Johann Koch (seventeenth century) and K. Koch (eighteenth century), both of whom worked in Berlin.
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Billmeir Collection