Optima (Union)

Toothed Gear adding machine

ca. 1912

The simple disc-shaped toothed gear adding machine with pin setting is a descendant of the Union with an improved means for displaying higher-value digits. The wooden box in which the disc is firmly mounted adds greatly to the stability of the machine when calculating and makes it easier to grip the machine. The transfer from the 2nd to the 3rd digit is performed by a pin that travels on the disk and engages the right of the two gears located on a metal bar. The transfer from the 3rd to the 4th digit is performed by a single tooth which travels on the 3rd digit and engages in a gear wheel of the 4th digit. The setting scale ranges from 1 to 99, the maximum adding capacity reaches 9999. The inventor of the disc adder was Jevrem Ugritschitsch (patent from 1902), the manufacturer of the Optima was Dr. Albert Hauff, Berlin-Halensee 6 (imprint on the lid). In its simple construction, the Optima resembles the Union from the same manufacturer and the totalizer Troncet, which does not even have a hundreds carry. The Rotula of the Scottish priest Brown from 1698, which already has a carry (for one more digit), can be regarded as the archetype of all these concentric toothed gear adders or machines.