Museo Galileo
Virtual Museum
Plumb level (gunner's level) and proportional compasses
    • Setting:
      Room VI
    • Maker:
      Pierre Galland
    • Date:
      18th cent.
    • Materials:
    • Dimensions:
      length 180 mm
    • Inventory:
    • Plumb level (gunner's level) and proportional compasses (Inv. 3695)

This instrument was made by Pierre Galland, about whom we have no information. It is a plumb level that also functions as a set of proportional compasses. At the swivel joint there is a small square plate for opening the legs at a right angle. A small bar housed in one of the legs can be placed crosswise to intersect the plumb bob (missing). The bar carries a graduated scale whose values decrease toward the center, serving as a degree scale (with two 45° sectors). The flat legs are engraved with several proportional scales: arithmetical scale, volume scale, area scale, and polygon scale on the front; scale for squaring the circle and metal scale on the back.