ca. 1919.]. Green painted wooden slant slope box 23.5 x 43.5 x 14 cms (narrowing to 6.5 cms at top), with metal hinged flaps at front and back, retaining rear metal holding clasp though missing upper edge clasp, and with metal carrying handle at top, with two rows of 10 metal fingers (i.e. two hands) pivoting on a metal rod within, the front row painted in reddish brown, the rear row in white, fingers between 7 cms and 10 cms in length; with remains of internal chain to keep the front flap secure; box a little soiled, with some cracking to green paint, general signs of wear and a little bumped and knocked, both inside and out; with mounted patent metal label along the top edge painted over in green but still readable; photograph of instruction label loosely inserted; a scarce survivor. A scarce and extraordinary early 20th century calculating machine, the invention of schoolteacher Wilhelm Wlecke of Gütersloh near Dortmund in North Rhine-Westphalia, a patent for which (DE331979) was granted by the German Reich on March 5th, 1919.
This striking, if somehow slightly sinister teaching aid, differs significantly in terms of optics and methodology from the traditional ball based calculators, such as abacuses, commonly found in school rooms across the world at the time. Based upon the idea that most young children and young adults use their fingers to learn to count, Wlecke’s ‘finger calculating machine’ was designed as a ‘teaching aid for elementary arithmetic lessons in elementary schools’, and comprises a wooden box with hinged flaps at the front and the back, and containing two rows of ten red and white fingers made of sheet metal, (thus two ‘hands’) and which can be moved individually. The box would be placed in front of the class on the teacher’s desk, who would then open the two flaps, and could then fold down each finger separately, to perform basic arithmetical calculations visible to the whole class. This visible ‘finger calculator’, Wlecke believed, would be particularly useful for children who were under-performing in mathematics. By turning the lesson into effectively a small theatre performance, he hoped to create a lasting memory of the processes under discussion, through visualisation.
Wlecke subsequently published an accompanying textbook ‘Die Finger als Fundament des ganzen Zahlenbaues’ in ca. 1923, which apparently went through various editions, all of which are now are extremely scarce, with only a handful of the 1929 edition located on OCLC in German Institutions. To further accompany the device, Wlecke produced some additional illustrated charts and tables, and which are depicted in the HNF blog post.
Despite his best efforts, the machine proved too difficult to use, and indeed ran counter to the more widely held pedagogical theories that ‘counting on the fingers’ should be discouraged. Perhaps too, it was just too reminiscent of the nightmare inducing Struwwelpeter! Other examples found are located in various educational and state museums across Germany, suggesting that Wlecke travelled quite extensively to try and disseminate his methods. Indeed the Schweizer Schule magazine (p. 352, vol 44, 1931) reports upon a successful demonstration given by him in the Swiss community of Stans. Nevertheless, his machine and system failed to find widespread support, and it is our understanding that only a small number of the machines were in fact produced, handmade by Wlecke himself, and production appears to have ended in around 1930.
A photograph of an instructional sheet mounted on a previous example handled and now at UCLA is included.