Neuhöfer & Sohn thread planimeter

A planimeter is an instrument for determining the surface area of flat surfaces, e.g. an area on a map. Measurement of the area of geometric shapes is possible in many ways, which results in there being several types of planimeters, which use different principles of operation and are built in different ways. The first planimeter was designed in 1814 by Johann Martin Hermann, after which a rapid development of different designs of these devices followed. The planimeter presented here is relatively simple. It has the form of a frame equipped with parallel threads placed at small distances from each other. After applying on a drawing or map, the frame allowed measuring a surface by breaking it up into a series of stripes, whose total length defines the surface area of the shape. Manufacturer: Neuhöfer & Sohn, turn of 19th/20th c. Inv. No.: MIM90/XI-7 Model prepared on the basis of photogrammetric measurements. Licence: CC BY-NC-SA