Mathematical Instruments
Mechanical Instruments for Drawing, Measuring and Integrating
Drafting Instruments
Rechenscheiben und Rechenwalzen
Planimeters and Integrators
Alfred J. Amsler & Co.
Gottlieb Coradi
Ott & Coradi
Polar Planimeter
Rolling Disc Planimeter
Polar Disc Planimeter
Rolling Sphere Planimeter
Polar Sphere Planimeter
Compensating Polar Planimeter
Chart Planimeter (Siemens & Halske)
Curvimeter
Checking Disk
Coradi AG
Integraphs
Hünenberger-Murbach
Various Makers