Mathematical Instruments
Mechanical Instruments for Drawing, Measuring and Integrating
Drafting Instruments
Rechenscheiben und Rechenwalzen
Alfred J. Amsler & Co.
G. Coradi Zürich
Ott & Coradi
Polar Planimeters (until about 1893)
Polar Planimeters (around 1893 - 1900)
Polar Planimeters (from about 1900)
Special Purpose Planimeters
Polar Disc Planimeter
Polar Sphere Planimeter
Rolling Disc Planimeter
Rolling Sphere Planimeter
Chart Planimeter (Siemens & Halske)
Curvimeter
Checking Disk
Integraphs
Coordinatographs
Coradi AG
Hünenberger-Murbach
Haag-Streit
Various Makers
