Small table calculator
with wooden base
Brass, height 112 x 180 mm
A replica according to the plans of the renowned Swiss astrolabe maker Martin Brunold. The small instrument observes the principle of the table calculator, which was designed by Wilhelm Schickard (1592 – 1635) for his friend Johannes Kepler: Napier-rollers and addition wheels.
Small table calculator
with wooden base
Brass, height 112 x 180 mm
Top right 6 Napier rods can be found for multiplication. A Napier schema (auxiliary device for division) and a square chart are engraved on the left. Behind that a stock of five Napier rods for the numerical series 0/1, 2/3, 4/5, 6/7, 8/9 can be found. The addition device below is composed of 5 rotary discs (Schickard: 6 discs), which can be operated with a pin.
Small table calculator
with wooden base
Brass, height 112 x 180 mm
Five numerical windows (at the bottom) display the result of the additions.
Semi-automatic decadic transmission according to the Haken system (e.g.Addiator), converted to circular discs. Multiple decadic transmissions are indicated by the character "X" within the result window and require a 180° rotation, where the pin has to be set at the hole "X". Subtraction as a complement addition.