Mathematical Instruments
Mechanical Instruments for Drawing, Measuring and Integrating
Drafting Instruments
Hommel-Esser Aarau
Kern & Co. Aarau
Gysi & Co. Aarau
Friedrich Gysi
Gysi & Co.
Glaus, Leuzinger & Cie.
Proportional Divider
J. Bossart Suhr-Aarau
Various Makers
Rechenscheiben und Rechenwalzen