Addiators and Slide Rules
The Pocket Adding Machine
Attached is a photo of the " The Pocket Adding Machine". It is complete with mock snakeskin slip case (not shown), stylus and instructions and probably dates from the 1920s. It measures 4.8" x 3" and is basically a Sterling version of the "Procalculo". The machine front has a rather faded finish.

Addimult Addmaster
It is an Addimult Addmaster, serial no. 802422, from the 1950s. It is a virtually exact copy of the pre-war Addiator. It is mounted in a steel case which doubles as a desk stand. It can be flipped over to access the subtraction side.


Here are photos of two Produx Original calculators. Both have green/clear vinyl slip cases and metal tipped, black plastic handled, styli. I also have the instructions from both - these cover both numerical and sterling calculators so I have two identical copies. Both calculators are 6.5" x 3.4". They were made in West Germany, probably in the 1960s. They are virtually identical except that one is sterling and the other is decimal.

All are views of Addiator serial no M076362 which is a Sterling model dating, I think, from the 1930s. It measures 7.1" x 4.8" and has a black leatherette case in which it can be flipped over for subtraction. Like all the big, early genuine Addiators it has the addition and subtraction slides on opposite faces. It weighs approximately one pound so it was a heavy item to carry around in a pocket.

This one is the Sterling "Correntator" made by Bergmann (CBR) in the 1930s, serial no 006800. It measures 6.4" x 4.7" and has the flip over panel for subtraction. It is housed in a leatherette wallet (somewhat distressed!) and has a stylus which has a propelling pencil on the other end.

This is a picture of the sterling "Kingson" this time. Being made for the British market in the 1950s or 1960s it is labelled "Empire made" and "Reg'd in Britain". I think it was made in Hong Kong and is a cheap copy of the Addiator Arithma in aluminium alloy, size 6.5" x 1.7". The stylus is metal. Britain doesn't have an empire any longer, except perhaps for Gibraltar and the Falkland Isles.

Faber Castell Addiator and Slide Rule
Recently I acquired a Faber Castell Addiator slide rule. It is a Faber Castell 67/87R with the date code for July 1949 stamped into one end of the slide rule - this I think makes it quite an early example of this particular model. The slide rule is a System Rietz one which was also sold by Faber without the addiator as the 67/87. Faber made a later version of this particular rule, the 67/87Rb. The scales on the slide rule were re-arranged and the addiator type was changed from the Arithma to the Universal which had the benefit of a negative number display as well as the usual central one, as illustrated in the pictures of JIm Cerny's Faber Castell 67/54Rb, which are already on your site. My rule is complete with leather slip case which has a promotional logo transfer on it for Weigel Optik vorm. Orthozentrische Kneifer GmbH, Nachf. H Weigel, Frankfurt/M, Muselstr. 28, Ecke Kaiserstr. 66, Ruf 23270 in addition to the impressed A W Faber Castell logo.
Incidentally, there is an archive of Faber Castell slide rules, including the addiator ones, on the Sphere Research web-site, www.sphere.bc.ca/test/2archives.html

Addifix 6
This is an Addifix 6 calculator, made by Addimult (Hans-Wolfgang Kubler). Apart from the name it appears to be identical to the Sumax 6 and I believe that it was also sold with other brand names. It is a 6 x x 6 machine with addition on one side and subtraction on the other. Its serial number is 564636. Date is probably around 1960,

Addiator Universal Standard
This is an Addiator Universal Standard which is basically an Arithma but steel rather than aluminium or brass. According to a Harrison Industries leaflet that I have it sold for $2.98 whilst the Arithma in Al sold for $3.98 and the brass one for $4.98. The price list also gives prices for the Duplex Aluminium, Brass and Executive models as $9.48, $10.98 and $15.95. Regrettably the leaflet is undated.

Sterling Dial-a-matic
This is a Sterling Dial-a-matic adding machine (No 567 five digit desk top model) with its original packaging and stylus. This is a cheap plastic machine which came in a number of versions, some only four digit, and some combined with a pencil box. Sterling Plastics were suppliers of educational items including also cheap slide rules and drawing templates, so I guess these were aimed at school children.

Machine a Calculer - Rebo
Rebo Machine a Calculer, made in France. It probably dates from 1925 - 1929 and may have been sold through UNIS. UNIS was an organisation representing French manufacturers rather than a manufacturer itself, founded c1916.

Source: David Riches's Collection

X-Number World of Calculators