Krüger’s calculating pencil case

A computer for every child, 1909 style

The slogan “A computer for every child!” has been used for various commendable programs led by technology leaders, educators, philanthropists, and politicians in numerous countries over the past decades. The earliest incarnation of this phrase, however, may go to the German teacher Georg Krüger, who used it in the advertising brochure for his patented Rechen-Federkasten, or “calculating pencil case”. The battered photocopy I have is bilingual, and states in a somewhat stilted translation “To each pupil his own counting machine!”

Ad for Krüger's Rechen-Federkasten
Click image to see the full ad

The counting machine in question is a far cry from today’s iPad, but is manufactured with a loving attention to detail. The computing part is a two-digit abacus, twenty beads in two rows. This folds neatly into a fairly ordinary pencil case, except that unlike other pencil cases I’ve seen (including the one I was taught to make in woodworking class in my elementary school) its body is machined precisely from a single solid block of hardwood. The abacus takes up one compartment in the case, with another available for a few pencils or perhaps a nib pen or two. To use the abacus, it is pulled upright and the lid of the case is slid back in, to keep it in this position.

This simple device was invented and produced by one Georg Krüger, a teacher from Berlin, and he has diligently patented it in Germany and in other countries. The German patent can be found online here and has a grant date of June 3, 1909; the US patent is here and was granted three years later.

Krüger's Rechen-Federkasten

Here are some more photos of the smooth-moving implementation, which reflects top-notch woodworking.

Herr Krüger, as a teacher, was clearly acquainted with the challenges of keeping a disciplined classroom. The patent states: “The object of this invention is to provide a combined adding apparatus and pencil box for children; said apparatus differing from similar existing apparatus in that the rod or rods, carrying the beads is or are turned into the box while out of use, so that the child’s attention is not attracted by the beads and no cause is given for play during lessons”. Indeed, the children photographed in the brochure stare forward in a most orderly manner, as if horrified by the very idea of playing. Those were the days…

Exhibit provenance:
An antique shop in Berlin’s wonderful Antique- and Flea-market arcade in Georgenstrasse.

More info:
Here is the full advertising brochure for Krüger’s Rechen-Federkasten.

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