Vintage A.W. Faber “Columbus” No. 342 Commercial Slide Rule – System Rohrberg

Vintage A.W. Faber “Columbus” No. 342 Commercial Slide Rule – System Rohrberg – Made in Bavaria

A wonderfully evocative vintage A.W. Faber “Columbus” commercial slide rule, model No. 342, made in Bavaria and presented in its original black fitted case. This is a particularly interesting example of a pre-digital calculating instrument, designed not just as a measuring rule, but as a practical commercial tool for business, trade and calculation.

The case is beautifully marked in gilt with A.W. Faber, “Columbus”, Syst. Rohrberg, D.R.P. No. 206428 and a D.R.G.M. registration number. The rule itself is also marked A.W. Faber “Castell”, 342, and Made in Bavaria, placing it within the respected Faber-Castell family of technical and drafting instruments.

This type of rule would have been used by merchants, clerks, exporters, engineers, accountants and travelling salesmen in the days before electronic calculators. The Columbus System Rohrberg was intended for commercial calculation, including multiplication, division, percentages, exchange calculations, ratios, simple interest and trade conversions. The reverse is especially charming, with printed conversion tables for Great Britain, India and the U.S.A., including pre-decimal British currency, imperial weights and measures, rupees and annas, gallons, bushels and other trade-related units.

The piece dates most likely to the inter-war period, circa 1920s–1930s, and has a lovely period presence. It is a tactile reminder of the world of ledgers, shipping invoices, imperial measurements, export houses and hand calculation — a fabulous object for collectors of scientific instruments, commercial history, vintage office pieces, drafting tools or Faber-Castell ephemera.

The rule is made with a wooden body and pale celluloid-style scale surfaces, with a warm wooden reverse and printed conversion panels. The central slide moves, and the original black case is present. No separate transparent cursor/runner is apparent, so the item is offered exactly as photographed.

Condition

In good vintage condition overall, with expected age-related wear. There is surface marking, discolouration and foxing to the pale scale surfaces, along with rubbing, small scuffs and wear to the wooden edges and case. The gilt lettering to the case remains attractive and legible. The central sliding section moves. No separate transparent cursor is visible. Please see photographs for full details of condition and markings.

Approximate size

Approximately 38 cm long when closed.

A fascinating vintage A.W. Faber commercial slide rule — part mathematical instrument, part office relic, and part social-history object from the age before calculators.

General note: Vintage and antique items will usually show signs of age, use and handling. Photographs form part of the description, and colours may vary slightly depending on screen settings. Description is given to the best of our knowledge.