Notes: "It seems that in one way or another, Otto Meuter’s name comes up when discussing just about any slide adder. Meuter designed a slide adder based on the earlier “Trick” slide adder of 1911. Carl Kuebler’s Addiator company produced Meuter’s adder, paying him a royalty of 50 cents per adder sold. Inflation soon made 50 cents worthless, and when Kuebler would not renegotiate the contract, Meuter partnered with another company, Continentale Buro_Reform Jean Bergmann (CBR), to produce slide adders under the brand names Correntator and Pro-Calculo. In 1928 Meuter finally founded his own company, Werkstatt Otto Meuter, in Berlin, and produced slide adders under the brand name Produx. After WW2 Meuter’s company split in two, with Produx calculators continuing to be made in West Germany, and Record calculators being made in East Germany. This Produx Original is a relatively late model, dating from the 1960’s. It’s quite a large hand-held slide adder, measuring 6.25” tall and 3.5” wide, but it’s only 8 columns. Most slide adders this wide would have 9 or more columns. "
