Eduard Hammenstede
Key Points Eduard Hammensted was a watchmaker who lived in the 19th century. He invented a column-type adding machine. He submitted the patent in 1882, but his machine was never commercially produced. History of Computers and Computing, Calculating tools, Gadgets, Eduard Hammenstede Eduard Hammenstede On March 31st, 1882 Eduard Hammenstede of Cologne, Germany, received German patent No. 20443 on Schnell-Addirmaschine (Quick Adding Machine). The device was a column adder with a large numeral drum and keys, arranged in two rows and as a whole looked very much like the earlier calculating machine of Thomas Hill...