Mathematical Instruments
Mechanical Instruments for Drawing, Measuring and Integrating
Drafting Instruments
Rechenscheiben und Rechenwalzen
Alfred J. Amsler & Co.
Jakob Amsler (1856 - 1888)
Amsler & Co. (1888 - 1950)
Polar Planimeter
Polar Disc Planimeter
Compensating Planimeter
Radial Planimeters
Integrators
Amsler & Co. (1950 - 1982)
G. Coradi Zürich
Hünenberger-Murbach
Haag-Streit
Various Makers