Joseph Mrakh

After 1736, as a mining trainee, he produced several plans of the Idrija mercury mine, and in 1744 a map of Idrija. He mapped ore deposits in Carinthia, the Karawanks, the Central Sava Valley, and Moravia. He designed a new smelting facility in Idrija, an ore smelter in Banská Štiavnica (now Slovakia), and logging sluices: the Brus logging sluice (Brusove klavže) and Putrih logging sluice (Putrihove klavže) on the Belca River, the Idrijca Logging Sluice (Klavže na Idrijci), and the Smrečne klavže on the Zala River. After 1750 he mapped the roads from Idrija to Godovič and from Eisenerz to Trofaiach (in Austria). In 1752 he was a lecturer in surveying at the Idrija Mining School, and from 1763 to 1769 at the Metallurgical and Chemical School. He trained several cartographers, and his work was continued by his son Anton Mrakh (1739–1801). During its renovation in the 18th century, he decorated Assumption Church in Spodnja Idrija with frescoes. Due to Mrakh's significant contribution to Slovenian science, he was included in the book Sto slovenskih znanstvenikov (One Hundred Slovenian Scientists). Mrakh died in Idrija at the age of 77.

• Name — Joseph Mrakh • Born — 25 February 1709 • Birthplace — Idrija, Holy Roman Empire (now Slovenia) • Died — 14 August 1786 • Place of death — Idrija, Holy Roman Empire (now Slovenia) • Occupation — Surveyor, cartographer