Working tool

Pantometer, a technical instrument circa 1850–1900
Angle cross from the Netherlands, known as an équerre d'arpenteur (surveyors' square)
When mounted it measures 16 cm in height and 6.5 cm in width
In good condition with signs of aging
A piece of the lid, but this can be replaced
For determining plumb lines and laying out 90-degree angles
Surveyors looked through these fine slits at beacons in the landscape to draw an exact line
Attachment was usually on a wooden staff, called a jalon
Will be shipped by B post