The grave of János Pettkó in Upper Driethoma

János Pettkó of Upper-Driethoma (11 November 1812 – 20 October 1890) was an imperial and royal mining councillor, geologist and corresponding member of the Hungarian Academy of Sciences. ; Son of Dániel Pettkó, landowner, county magistrate and Krisztina Hradszky. He completed his studies at the Lutheran Lyceum in Győr and Bratislava. His father intended his son to be a priest, so he studied theology for two years and passed the priestly exam, but he was apprenticed to the second bailiff of Trenčín County. During his three-year apprenticeship, he mastered the sciences of law and, in addition to Hungarian and German, he also learned French. He took his law exams in Prešov. ; Returning home, at the age of 24, he went to Selmec, attended the mining and forestry course and learned English, during which he also won a scholarship. He was assigned as an intern to the Körmöc smelter, where his main duties were espionage and metal exchange. In 1842, he also participated in the assembly of doctors and naturalists held in Bánya Beszterce. At that time, by decree of the imperial and royal court chamber governing the mining and coinage affairs, he was called to Vienna for a daily allowance of 1 forint to listen to mineralogical lectures given by Wilhelm Haidinger. However, Pettkó was ordered to work in the chemical laboratory under the leadership of Sándor Loewe, the director of the mint, because even during the mineralogical lectures he was appointed inspector to the Aranyidka coinage office. However, he never took up this position, because he had to finish his course and pass the exam first. He was then immediately sent abroad on a study trip. He reached Andreasberg in the Harz Mountains through the regions of Bohemia and Saxony when he received a presidential decree from Baron Kübeck, according to which he was invited to Selmecbánya as a deputy teacher at the department of mineralogy and geology with a salary of 1,000 forints. He began his teaching career in October 1843. In 1847 he was appointed a regular academic teacher and the associated title of mining councilor. In addition, he was assigned to lecture on zoology, botany and geology to forestry students, and for many years he was also assigned the position of lecturer on current affairs of the academic council. ; He processed the data he collected during his studies in the form of a geological map and description of Selmecbánya and its region. His most notable achievement was his evidence for dating the nummulite layer in Vihnye, which put beyond doubt that the Selmec metal deposits originated in the Tertiary period and could not be traced back to an earlier period. In 1848, several people gathered in the house of Ágoston Kubinyi in Videfalva, including Pettkó, for the first meeting to establish a Hungarian geological and mining society, and in 1850 the society was finally established in Budapest. On December 20, 1861, he was elected a corresponding member of the Hungarian Academy of Sciences. In 1867-1868, his eyesight failed, so he was occasionally relieved of his teaching duties, until he was finally retired in 1871. He also suffered financial losses, so that his daughter and husband from Selmec took him in, first to the Great Plain, later to Bazin, to his son-in-law's estate, and finally to Bratislava for the education of his grandchildren. Pettkó also went with them and spent his last days there. The name of his family from Trenčín County also went to his grave with him. Baron Dénes Mednyánszky gave a memorial speech about him at the Hungarian Academy of Sciences on May 30, 1892.