Alois Salcher

At the beginning of the 20^th century, the Austrian engineer and businessman from Innsbruck Alois Salcher devised and produced a fascinating calculating machine. Despite its original construction, the machine of Salcher was never much of a success, and it is rare today. The known serial numbers indicate a production run of about 400 machines, and despite production being stopped since 1908, it was still advertised and sold by the end of 1910.

Salcher got patents for his calculating machine, the so-called ADSUMUDI (after ADdition, SUbtraction, MUltiplication, DIvision), in several countries—Austria (patent AT35115 from 16 Sep 1906), Germany (DE204333 and DE209009), Great Britain (GB190623173 and GB190906657), France (FR370829), and the United States (US974006). Salcher shared two of the patents with Nikolaus Werle, a merchant from Stuttgart. Some patents (e.g. the American one) are for an improved machine, in which the entire principle of operation has been changed, and that has obviously never been manufactured. ADSUMUDI was produced in Germany by the machine factory of Carl Werner of Villingen (the factory had a branch in Innsbruck), one of the largest watch manufacturers in Germany.  It was a messing device with dimensions 39x30x12 cm, and a weight of 12.4 kg.

The operating principle of this 10-positional calculating machine is quite different from any other mechanical calculator ever manufactured. To move the gears with the result wheels attached to them, it has rectangular plates with a slot in the middle and a gear rack on either side of the slot. Depending on which way the result register moves, the gear engages with the rack on the left or the right of the slot, thus reversing the direction of the result register from addition to subtraction and vice versa. The racks are connected to the spring-loaded setting levers so as soon as they are released, they re-zero themselves and transfer their value to the result. All the rest of the complicated mechanism is designed to engage and disengage the correct side of the rack with the result at the correct time, and to make sure the result register is locked when it is not in engagement with the racks.

ADSUMUDI was suitable mainly for addition and subtraction. The name, however, indicates that the machine would also be able to do multiplication and division, and for this, an extra tool is needed, namely a template for repeating the setting of numbers in the input. This takes the form of a sliding carriage, which sits on vertical rails and can be coupled to the operating lever so that every time the carriage slides up, the number is added or subtracted, and every time the carriage slides down, the number is reset into the input. In addition, this carriage can also slide to the left and to the right, to allow for column shifting in multiplication or division. In this respect, the ADSUMUDI is similar to Stanhope‘s four-species calculating machine from 1775.

Sadly, the ADSUMUDI lacked a revolution counter-register, and the operator needed to count the number of repeated additions or subtractions in a multiplication or division and write them down digit by digit. This is obviously tiresome, requires concentration, and much reduces the automation of machine calculation. The machine remained insignificant on the market and can be viewed as a cleverly extended adding machine. The multiplication process takes place at great speed, but the lack of a revolution counter meant that this not-very-cheap machine could not compete with real four-species calculating machines.

Biography of Alois Salcher

Alois Salcher was an engineer and businessman from Innsbruck, Tyrol. He was the owner of Innsbrucker Dampf-Teigwarenfabrik (pasta factory), had a machine workshop, and was engaged in the real estate business. Salcher was a fan of technical novelties and in 1896 he demonstrated the first automobile in Innsbruck.

In the middle 1890s, Alois Salcher married Emilie Hruschka-Salcher (1870-1930), the daughter of the local dentist Josef Hruschka (1843-1913). The Hruschka family, originally from Moravia, was a famous Austrian family of dentists, and Emilie Hruschka became the first female dentist in Tyrol and Austria. Alois and Emilie had two sons—Alois and Hubert (born 1 Jan 1905), who became doctors and Nazi party members and served in the army during WWII.

Besides the above-mentioned patents for calculating machines, Alois Salcher has one more patent—for Bundle seals for barrels (pat. №DE100118 from 1897).