Fig. 29 Fig. 35
The square format of this instrument is unusual and includes several different components, several now incomplete. Among its operations, artillery uses are most strongly signalled by the small vignette of a firing gun incorporated into its engraved decoration.
The instrument's central slit has a scale of inches and would once have housed a sliding gunner's sight. Another missing piece is the plummet which hung to the side of the sight. There is a table for converting between feet (SHV - Schuh) and paces (SHRI - Schritt), such as is found in range tables like those published by Leonhard Zubler (catalogue no. 13). The table correlates with another on the other side of the instrument. Of further use to gunnery, though for more general surveying purposes too, are a shadow square and quadrant, along with two sighting rules. A pivoted compass and a sundial (lacking its gnomon) are both designed to be used with the square plate upright; the necessary stand is now missing.
Dimensions: 143 x 143 mm
Lewis Evans Collection
Inventory no. 46,878