In 1901 the young German inventor and businessman Justin Wilhelm Bamberger (born 20 August 1879 in Würzburg) moved from Cologne to Munich, where in 1902 he registered a company for office equipment, under his name, and also started a small repair shop that dealt with used typewriters. Presumably, he also sold the “Locke-Adder”, which he imported from the USA, then he decided to design his own calculating and typewriting devices. Starting in 1903 he brought out four simple calculators and two typewriters, which he produced, although in small quantities, in his factory (Präzisions-Maschinenfabrik Justin Wilhelm Bamberger & Co.).
The Universal Adder of Bamberger (see the nearby photo) was similar to George Fowler‘s Adding Machine from 1863 and to Locke Adder from 1901. It was patented in Germany (D.R.G.M. 195509 of 8 April 1903). Like Locke Adder, the Universal Calculator does not carry tens, it is only used to set amounts. A tens carry must be calculated mentally and also set. The device has dimensions of 38,8 x 11,3 x 1,8 cm, a weight of 530 g, and was in production from 1903 to 1914, with an initial price of 15 Marks.
In 1905 Bamberger improved the Universal Adder and launched “Omega” (see the nearby photo), with an initial price of 38 Marks. The device has dimensions of 39,2 x 11,5 x 2 cm, and a weight of 730 g. The Omega calculator (see the Usage Instruction of Omega) has hod-shaped number slides with punctiform elevations that the finger can grip. The result is shown under round windows. To the right of the input field, there is a hole for each position, into which a comma pen can be inserted. On the right side of the device, there is a holder for a notepad. On the cover of the box is inscribed a multiplication table with sliding elements. In the right part of the box is a compartment with a lid for storage (pen, etc.) The device does not have tens carry.
In May 1906 Bamberger announced a new portable and cheaper version of Universal Adder called the “Dux” calculator, with a price of 4.5 Marks. In June 1906, he launched a rather different calculating device—Bamberger Ideal (see the nearby photo), with a price of 25 Marks.
The Ideal calculator of Bamberger is a concentric toothed-disc adding machine with dimensions 2 x 11 x 15 cm, and a weight of 240 g. During the setting of the device, one of the six concentrically arranged number disks is moved with the setting pin, whereby one of the six buttons underneath the setting disk (for the digits 1–100000) the respective dial is released from the blockage. The black (outer) numbers apply to addition and the red (inner) numbers apply to subtraction. The device has tens carry, i.e. if “9” is exceeded, the tens are carried over to the next higher number disc (via an internal “carrier” tooth). Above the row of buttons on the left is a reset button, which is pulled to the right to reset, releasing the locks on the six dials; when the setting pin is actuated, all six number discs snap into the “0” position one after the other. The machine, which is very pretty thanks to the two-tone materials, is decorated with floral arabesques and a border.
Bamberger was a holder of quite a few patents in Germany, France, Great Britain, the USA, Switzerland, and Denmark, mainly in the area of typewriters, but also for calculating devices, a fountain pen, a vacuum cleaner, etc.
In late 1909 Bamberger’s last company (D.K.W. “Deutsche Klein Maschinenwerke Justin Wm. Bamberger & Co”), which produced his typewriters Liliput and Helios, went bankrupt, so he left Munich and moved to Berlin, where he founded “Helios-Schreibmaschinen-Gesellschaft” to sell his patented typewriter Helios, now produced by another company. It seems Bamberger was a good engineer, but a poor businessman, because Helios had also become an economic failure for him. The last available information for Bamberger is from the middle of 1912 when he was the managing director of the “Allgemeine Spezialmaschinengesellschaft” in Hamburg, which manufactured vacuum cleaning machines (he had patents in this area, e.g. GB191126843).