J. Louis Troncet Arithomgraphe 1889
Here is a good paper on the history of the Addiators and the Magic Brain Calculator brand of slide adder made in the United States. (need author's name).
One of the most popular versions of the slide adder was the Addiator, which was newly designed by Carl Kübler (born 1875) and manufactured in Germany as Addiator GmbH. Küubler capitalized on the fact that the original patents by Otto Meuter had expired. Introduced in 1920, over 100,000 units were sold in the first year, and versions of this device remained in production as late as 1975. Featuring a novel carry mechanism, the Addiator could be used to add or subtract, but addition and subtraction required two different control panels. In early versions of these devices, the two panels were provided by flipping an overlay on the front or by having the addition function on the front and the subtraction function on the back (later models had two separate panels on the front). The addiator is comprised of three components, the body containing multiple slides used for calculation, a stylus, and a handle to reset the addiator. The calculations are performed by inserting the tip of the stylus in notches in the metal plates in the addiator. There are other variations involving dials or tables as shown in the gallery. The narrow versions of Addiators were incorporated on the back of some models of Faber-Castell slide rules, and others. Note, although there were many other manufacturer's of slide adders, the name Addiator (by the German firm of the same name) has become synonymous amongst collectors of these devices just like Xerox for a photo copy and Kleenex for tissues.
