"Artillery Rise At Signed Inclinometer, Germany, XVIIth Century"Artillery rise or inclinometer with brass sighting of rather unusual asymmetrical triangular shape. It is signed with the initials "FS", German and dating from the second half of the 17th century. The instrument measures 14.2 × 10.1 cm and 7.2 cm in height. A nice size lead with a decorative shape moves horizontally on a circular scale graduated in degrees from 47-0-47 divided every 5 degrees. The observation is made through a series of 16 small holes drilled in the middle of the brass plate, from top to bottom. The holes have intervals of about 1.8 mm but their spacing is not perfectly regular. On the other side is engraved a small square of shadows divided into German inches (about 25 mm each) from 0-4-0. For a very similar example of size, it seems, absolutely identical but mounted on a rounded support see the Oxford History Museum of Science: https://www.mhs.ox.ac.uk/geometry/ cat25.htm Furthermore, even if we cannot assign the signature "FS" to a particular manufacturer, we know of other instruments from the 16th and 17th centuries bearing these initials. Websterdatabase cites four instruments including a surveyor's square dated around 1580 and kept at the Adler Planetarium and a level from the collection of Alice Morse Earl. Very good original condition, the instrument has only been cleaned.