A 1886 patent for a multiplication machine modeled after a pantograph established Eduard Selling as a mechanical innovator alongside his primary career as a mathematician. Born in Ansbach in 1834, he spent his professional life navigating the German academic landscape while contributing to fields ranging from quadratic forms to the reorganization of Bavarian state pension systems.
Academic Training and Appointment
Selling pursued his mathematical education at the University of Göttingen and the Ludwig-Maximilians-Universität München. Under the supervision of Bernhard Riemann, he earned his doctorate in 1859. The following year, he secured a position as professor extraordinarius at the University of Würzburg. This appointment proceeded despite opposition from the faculty and the mathematics professor Aloys Mayr, following a recommendation from Leopold Kronecker. Beyond mathematics, he expanded his academic responsibilities at Würzburg by teaching astronomy and serving as the conservator-restorer for the astronomical department starting in 1879.
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In 1873, he published research regarding binary and ternary quadratic forms. This work received international attention, appearing in translation in French and gaining citations from Henri Poincaré, Paul Gustav Heinrich Bachmann, and Émile Picard. His expertise later extended into actuarial science, where he assisted the Bavarian government with pension system reorganizations starting in 1877. Despite his scholarly output, his career advancement remained stalled; an application for promotion to professor ordinarius was rejected in 1891, and he eventually retired as an emeritus professor in 1906.
Mechanical Computation and Invention
Selling sought alternatives to the calculating devices produced by Thomas de Colmar to support his own computations, such as signed-digit representation. He developed his own multiplication machines, securing a patent in 1886 and receiving recognition at the 1893 Chicago World's Fair. His production output remained limited, with approximately 30 to 40 units manufactured by 1898. He experimented with improved models and a third electrical machine, for which he held a patent from 1894, receiving technical assistance from Christel Hamann. Several of these devices currently reside in the collection of the Deutsches Museum in Munich.
Fast facts
- Born: 1834, Ansbach
- Died: 1920, Munich
- Doctoral advisor: Bernhard Riemann
- Primary employer: University of Würzburg
- Mechanical patent year: 1886
- Chicago World's Fair award year: 1893
- Retirement year: 1906
Questions readers ask
What subjects did Eduard Selling teach?
He taught mathematics and, beginning in 1879, astronomy at the University of Würzburg.
Did his calculating machines become commercially successful?
No, the machines were considered complicated to produce and use, with only 30 to 40 units produced before 1898.
Achievements
- Held posts at University of Würzburg
- Fields: quadratic form, actuarial science and mechanical calculator
