A quite unusual asymetric triangular (certainly) gunner’s level and sight made in full brass and signed “FS”. The instrument is German and from the 17th century.
It measures 14,2×10,1 cm and height : 7,2 cm
When used as a level, the rigid plummet, which is finished with a very nice shaped and large plumb bob, of this triangular brass instrument moves over a quadrant scale graduated in degrees 47-0-47 and also divided all the 5 degrees.
Sighting is accomplished through a series of 16 small holes pierced through in the middle of the quadrant plate, up to down.
The holes are approximately 1,8 mm intervals but are not perfectly regular so sighting observations could therefore only have been approximate.
By contrast, the scale on the quadrant arc is continuous and so should permit finer readings.
On the other side is engraved a small shadow squarre divided in 0 to 4 to 0 in a German inches measuring approximatively 25 mm (so for a German foot measuring around 300 mm).
For a very similar example of same size but mounted on a rounded stand, see Geometry of war : https://www.mhs.ox.ac.uk/geometry/cat25.htm
We know some other “F.S.” signatures on early instruments.
Websterdatabase cites four different instrument including a surveyor’s cross, circa 1580 at the Adler and a “Level” in the Alice Morse Earl collection.
Very fine original condition, the instrument has been only cleaned.
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