Plössl in Vienna, „Kleiner Rundfuß" microscope, ~1850
The reality after Napoleon's defeat and the Vienna Congress cultivated a bourgeois apolitical lifestyle, which is known as the “Biedermeier culture”. The emperor's residence attracted significant forces from the German-speaking world which, thanks to the many foreign influences, enabled great achievements that made up the cultural splendor of Vienna at the time.
The collaboration with scientists promoted optical industries, which reached a temporary high point with the products of the Viennese optician Simon Plössl (1794-1868). Until the introduction of scientifically calculated optics - founded by Ernst Abbe at the Carl Zeiss company in Jena - his devices were highly esteemed by users in Europe. Plössl's composite achromatic microscope won first prize at a gathering of German naturalists and doctors in Heidelberg in 1829 over similar instruments such as those from Amici of Modena, Dollond in London, Fraunhofer in Munich, Chevalier, Oberhäuser or Selligue in Paris.
Simon Plössl came from a Viennese family of craftsmen. He learned to read and write from his father, who gave him an apprenticeship as a master turner at the age of 12. After completing this apprenticeship, he then started another apprenticeship because he wanted to become an optician. So on May 9, 1812 he came to the well-known master optician Friedrich Voigtlaender, who had worked for Ramdsen in London for several years and had been running a workshop in Vienna since 1807. At that time, he produced small pocket and compass microscopes as well as achromatic lenses for research purposes. It can be assumed that the achromatic lenses produced there from 1817, which are among the first in the German-speaking area, came from Plössel's make. In the period up to November 27, 1823, he worked as an apprentice or later as a journeyman. He learned all the work from Voigtlaender that was necessary to found and run an independent company. Above all, he got to know his most important sponsors there, the botanist and director of the botanical garden, Josef Freiherr v. Jacquin, for whom he sometimes made difficult custom-made products, and the astronomer and director of the Vienna University Observatory, Josef Johann v. Littrow. Both encouraged Plössl to open his own workshop. On their advice, he attended courses in mathematics and optics at the Polytechnic Institute and at the University of Vienna. This knowledge enabled him to improve his optical devices. After eleven educational years with Voigtlaender, he finally opened his own workshop in 1823 and produced binoculars, glasses, theater perspectives and so-called aplanatic magnifying glasses, which were named after him and were widely sold.
Around 1850, Plössl's microscope stands were made with the typical round base (seen here) instead of those with the flat tripod base. Plössl now also manufactured eyepieces for insertion instead of screwing in as before. The "Small Round Base microscope" seen here was equipped with a round brass stage with recessed black matt glass insert and two brass object holders mounted on an eccentric column. Typically to Plössl (after his earliest models), the stand was based on a prismatic rod. The concave mirror in gimbal suspension, on a double curved arm (usable for oblique lighting). The optics include a three-part achromatic lens set (No.1 to No.3).
Gregor Johann Mendel (1822-1884) was using Plössl microscopes including this small model for his seminal experiments on the pea plant heredity, conducted between 1856 and 1863, to establish the laws of Mendelian inheritance. This in turn set the rules for modern genetics.
Gregor Mendel's small Plössl microscope with a dow cap at the Mendel Museum, Masaryk University in Brno, Czech Republic