Notes: "It seems that in one way or another, Otto Meuterís name comes up when discussing just about any slide adder. Meuter designed a slide adder based on the earlier ďTrickĒ slide adder of 1911. Carl Kueblerís Addiator company produced Meuterís 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 Meuterís 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 1960ís. Itís quite a large hand-held slide adder, measuring 6.25Ē tall and 3.5Ē wide, but itís only 8 columns. Most slide adders this wide would have 9 or more columns. "