29.6. 1793 Josef Ressel is born

Josef Ressel's discovery of the propeller accelerated transport on water, although it is disputed whether he was actually the first inventor of this technical innovation. He drew a sketch of an airship powered by an Archimedean spiral during his studies in Vienna.

Josef Ressel was born in Chrudim into a Czech-German family. His father was a toll and tax collector Anton Hermann Ressel and his mother Anna Marie née Konvičková. He also had a brother, who became a priest in adulthood, and two sisters. The nationality of his parents is a frequent subject of controversy, as Ressel is today claimed by Austrians, Germans, Czechs, Slovenes, Croatians, and even Italians. Anton Hermann was an Austrian German, and most authors refer to his mother as Czech, while others cautiously state that she came from a Czech family, and still others satirize her Czech ancestry with the word "perhaps".

Ressel studied at the gymnasium in Linz, Austria, and after graduating in 1806 he entered the artillery school. From there he went to the University of Vienna, but his family became poor and could no longer support him in his studies. Nevertheless, fortune smiled on Ressel, as he received an imperial scholarship that allowed him to study at the forestry academy. He then worked as a forester in Cracow, Trieste and Ljubljana.

"For Josef Ressel, who supported a large family, the profession of forester represented a secure livelihood as well as a subject of professional interest. He was the author of a specialist publication, The History of Coastal Forests, which brought him more recognition than his technical inventions during his lifetime," writes Jan A. Novák in his book The Hidden Personalities of Czech History.

He drew the first sketch of an airship powered by Archimedes' spiral during his studies in Vienna. However, at that time there was no suitable light engine for such a means of transport, so the inventor decided that the application on a ship was more realistic. "After experimenting with models in 1826, he built a propeller into a boat, with two men turning its shaft. The following year, Ressel received a patent for his propeller," Novák adds.

However, the test voyage on 4 August 1829 was not successful, the poor quality steam line broke and the police banned further attempts. Moreover, Ressel's partners did not pay the renewal fees for the patent, which lapsed in 1831. Nevertheless, he was good for something, and in 1866 the American Academy in Washington officially awarded the invention of the propeller to the Chrudim native. In fact, we can find the Archimedes spiral drive already in Leonardo da Vinci's drawings.

To this day, however, Ressel is still praised by many. "He is our inventor of the propeller, whose invention has gained in importance and value in recent times because it could be adapted to the construction of an aerial machine. For the propeller of a ship and the propeller of an aeroplane are essentially the same thing," says, for example, Topic's Collected Works.

Sources. Novák, Secret Personalities of Czech History, Topič's Proceedings https://edu.techmania.cz/