Signed: [crown] M:E: Anno 1686. [also signed] HR
Fig. 33 (4th from left).
Rather than having a single sighting hole sliding in a slot, this instrument has a long slider pierced with a sequence of seventeen holes. Only slight adjustments of the slider are therefore necessary to set a hole against a particular elevation. Settings are read off from a scale of inches subdivided to twelfths. The level is offset from the sight, to avoid obscuring it, and has a brass plummet moving over a 45° arc. By the later 17th century it was becoming more common to graduate levelling arcs using the degrees of the 'astronomical quadrant' than to use scales appropriate to only one particular gun or variety of shot.
Height (slider not extended): 125 mm
Inventory no. 42,501