Water that keeps the mining above water
Tajchs. Today, picturesque lakes for swimming and ice-skating; in the past, essential parts of a mining water-management system perfect for draining flooded mines. In the 18th c., the system collected more water than any similar one in the world. How was it possible? There are only a few springs and small creeks around Banská Štiavnica. It was mainly the Hell family and Samuel Mikovíny who, nevertheless, saw the potential for and designed this ingenious system of water reservoirs and channels.
Once upon a time, as the sands shift and waters run…
Tajchs could have been found in the surroundings of Banská Štiavnica as early as the beginning of the 16th c. They served as reservoirs for water to drink and to fight fires. Veľká Vodárenská lake drowned more than fires, though, even when there was no need for it. Its dam ruptured twice (1633, 1725), killing people, tearing down houses, and flooding yards and cellars with mud. Before the use of tajchs to drain water from mines, this task fell on the mine workers. For example, in 1687, out of a total of 2,173 working at the the Upper Bieber Mine, as many as 720 people, dealt only with water. Mining grew ever less profitable, but the nobility wished to maintain it no matter what. So, people had to start thinking about how to get water out mines – fast and cheap.
Finally done, finally dry
Rumours about mining problems in Štiavnica attracted many inventors to the town. But, they all failed. However, in 1693, Matej Kornel Hell came onto the scene as head mining engineer. He first impressed all by inventing a new type of “horse whim” (a machine driven by the power of teams of horses), then by building water reservoirs, and finally by having an impressive son, too, Jozef Karol, whose water-column pumping machine was the most effective water pump in the world in its time, eventually used in mining centres far and wide. Samuel Mikovíni took it even further. He designed a system of very reliable and economical water reservoirs and tens of kilometres of collecting and connecting channels, whose task was to transport water to where it was needed. At the time, Mikovíni’s works surpassed the highest standards for water management construction anywhere in the world. Tajchs even steamrollered the competition of steam engines, and the reservoirs served their purpose until the introduction of electrical power. The tajch in Hodruša was the last to be used for mining purposes, serving the industry until the beginning of this century.
The pride of both Štiavnica and Slovakia
In the end, more than 70 tajchs were built. The construction of the brilliant waterworks did not always go on brilliantly. For example, workers failed to follow Mikovíni’s specifications when building Kolpašské lake; as a result, leaks and cracks developed in the dam. Leaking spots appeared at Richňava reservoir, too; and, to solve the problem, Mikovíni suggested dividing it in two, just as he had originally planned it. Building Richňava was a huge project – in 1740, as many as 5,283 people worked there. On the contrary, when Počúvadlo began to be built in 1775, only 6 workers turned up on the first day. Even later, Počúvadlo was more the work of women than men – it is said, because of low wages. Clearly, nobody expected that tajchs would one day be included on the UNESCO List of Cultural and Natural Heritage.
Easy as Hell
When Matej Kornel Hell came to Banská Štiavnica in 1693, few would have guessed that he would be a blessing for mining. Hell engaged in rescuing mines from underground waters, the commanders of Rákoczi’s rebels, and even from the Chamber Court. Matej Kornel even managed to ensure that the Emperor Charles VI stands out in history as a highly competent, beneficent monarch.
Before the arrival of M. K. Hell, horse whims, which operated crankshafts, were used in the mines. The crankshafts were extremely inefficient, so Hell figured out how to build a whim without a crankshaft. Experts tested the device for 9 long weeks, and admitted it was without fault. Another of Hell’s inventions rescued the Upper Bieber Mine from being attacked by Rákoczi’s followers, who had been marauding Štiavnica since 1703. When the mines were flooded, the rebels wanted to destroy them for good. But Hell convinced the rebels that the water would disappear, thanks to his pumping machine. When the money assigned to the revitalisation of the Upper Bieber Mine had all been spent, the Chamber Court decided to close the mines. But, before the order became valid, Hell managed to design a way to drain the mines using water from the reservoirs to drive the pumping machines. That impressed even the Emperor Charles VI himself. Not only did he not close the mines, he even provided funding to build Veľká (Great) Vindšachta lake, and rebuild Malá (Little) Vindšachta and Evička lakes. With such an enormous amount of water and seven pumping devices, many flooded mines were saved. Thanks to Hell, Karol VI, too, stood at the birth of the most perfect water-management system of its time.
Slovak Da Vinci
If we wanted to erect a statue to Samuel Mikovíni for each profession he was a master of, the town would be filled with sculptures depicting him. One of the few fields he never mastered was medicine. And this proved fatal for the creator of the ingenious system of Štiavnica tajchs.
The multi-talented Mikovíni was the first Slovak to be granted the university title of “Engineer”. He was a mathematician, cartographer, copper engraver, surveyor, astronomer, speleologist, and water-management engineer; he designed defence structures, was the director of and a professor at a mining school, where he taught mathematics, mechanics, hydraulics, and measurement methods. He also taught practical classes on surveying. It is, however, unknown how many hours a day he devoted to sleeping. As the engineer of Bratislava County, Samuel Mikovíni had worked on water-engineering tasks, which he made good use of when the Emperor named him the royal geometer of the central Slovakian mining towns. This was a very good decision, for Mikovíny expanded and perfected the Hells’ system of tajchs, thus finally resolving Štiavnica mining’s energy problem. From among his most progressive works, let’s look in particular at the Rozgrund reservoir; it is such an exceptional structure that it would be a challenge to build even today, in our world of advanced knowledge and technologies. Mikovíni was an extraordinary man, for the way he lived his life as well as for his death. For scientific purposes, he outlined the Bratislava meridian, which comfortably crossed the window of his flat in Pressburg; and he had his own observatory right in his flat. As a mathematician, he successfully intervened in the debate on the quadrature of the circle. His copper engravings complemented the publications of Matej Bell. It might seem as if Mikovíny could do, and did, almost everything. But it was not so. We know that in 1750, Mikovíni was unable to recover from a simple cold, which ended his life suddenly as he was returning to Banská Štiavnica from Trenčín.