A fine 17th-Century German gilt gunner's level,

细节

A fine 17th-Century German gilt gunner's level,
signed Johann Koch fecit, the two cross-hair sights mounted on a limb with semicircular protractor graduated [0] - 180 running under a blued-steel pointer and locked by a tightening screw, raised on a adjustable support running between two vertical scales, both graduated in inches, one labelled Zoll [0] - 5, with captive plummet over pointer, and plummet running over an arc with two scales graduated [0] - 45, the foot of the assembly graduated and running backwards and forwards in an angled groove in the base, the whole mounted on a turned wooden disc with three wooden levelling screws -- 11¼in. (28.5cm.) high

See Colour Illustration and Detail

来源

Nicholas Landau Collection; Alain Brieux; Robert Seligman Collection.

出版

GUYE, Samuel and Henri MICHEL Time & Space Measuring Instruments From The 15th To The 19th Century (London, 1971)
ZINNER, Ernst Deutsche Und Niederländische Instrumente Des 11.-18. Jahrhunderts (Munich, 1972)

拍品专文

Zinner notes that Johann Koch is recorded in Cologne (his birthplace) in 1654, then in Vienna and Berlin, and finally, after 1665, in Stockholm, where he died in 1679. Six instruments by Koch are listed by Zinner (of which two are dated), including a gunner's level in the Arquembourg collection in Paris (p. 415).
The present instrument is described and illustrated by Guye and Michel (p. 277, "about 1670", plate 283).