Signed: Paul Carre Fecit Paris 1652
This instrument is included to show how polygonal scales, originally justified as useful for laying out fortifications, can be conventionally included on instruments whose functions are becoming distant from those required for ordinary military surveying. The general arrangement here is similar to that of the simple theodolite (see catalogue no. 61), but the central compass is much larger and, having its own degree scale, can function as a circumferentor; it is now surmounted by a prominent equinoctial sundial, whose inclination is adjustable on a latitude scale. Shadow-square scales have been added to the scales on the top surface of the plate and the reverse has a plumb-line moving over a quadrant. The scale of 'Polygons' is of the same type and is in the same position as on catalogue no. 61, but here is for three to twelve-sided figures.
Dimensions: 200 x 200 mm
Inventory no. 34,547