Jozef Karol Hell's water-pillar, water-pump machine for pumping mine waters, helped Banska Štiavnica become an important centre of silver mining, science, technology and education in Europe, in the 18th century.

The legacy of Joseph Karl Hell

By the end of the 17th century, a major construction of valley dams in Banská Štiavnica had been developed as a unique and ingenious water management system to provide water power for mining pumps. The system included 60 km long collection ditches, 16 water reservoirs (tajchs) and additional ditches 35 km in length. These water reservoirs were the lifelong project of Matej Kornel Hell (1653 – 1743). But it was the work of his son Joseph that had a global impact on mining.

Following his father's footsteps, Joseph Karl Hell (1713 – 1789) also became famous for developing ingenious mining machines and pumps. In the middle of the 18th century, most of the Slovak mines were flooded due to constant wars and plague epidemics that caused a decline in mining. The then primitive way of pumping water out of mines was not sufficient and required too many people and horses to power the whims. Workers had to carry water out of mines in leather bags, later by tread wheels and whims. Even legendary Isaac Potter's atmospheric pumping machines were not powerful enough to pump out the underground waters.

Where English “fire” machines failed, pumping machines constructed by young engineer Hell succeeded. As young as 25, he constructed wooden beam water pumping machine which pumped out almost 200 litters of water per minute, to a height of 80 metres.

Between 1749 – 1753, Hell worked on new, more powerful air pumping machines. The revolutionary machines proved themselves worthy, as they were very efficient and durable (they worked in one mine for 60 years). By 1770, 8 of Hell's machines were in use which earned him a place in history of mining technology.

The far-reaching contribution of Hell's pioneering work is primarily in using a new element – pressed air. His invention was revived in the 19th century in Arizona where two large mines were flooded. They used Hell´s pumping machines which dried the mines within 6 months. In Pennsylvania they used them successfully to pump oil out of great depths. The principle is still used today in oilfields but instead of pressed air machines, pressed natural gas is used.

Hell's revolutionary inventions significantly improved the working and social conditions of miners and made mining highly profitable. J. K. Hell together with Samuel Mikovíni completed mechanisation of mining gears and immensely contributed to the development of mining in Banská Štiavnica.