The earliest known examples of this device were from the first half of the nineteenth century in the silver mining area of the Harz mountains, Germany, where they were driven by cranks connected to water wheels, although bucket hoists ("Hakenkunst") using the same method of operation had been used in Swedish iron mines since the 17th century. They appear to have evolved from an informal modification to the beam pumps, where the miners used spikes stuck into the wooden pump rods to get themselves carried up the shaft. As beam pumps were universal in deep mines, it was a then simple development to make proper platforms to carry the miners. The first formal engine was installed in 1833 at a mine at Clausthal, Lower Saxony, where inspector Wilhelm Albert and manager Georg Dörell fastened foot platforms and hand-holds to adjacent, reciprocating pump rods, using a waterwheel-driven pump put out of use when a new drainage adit was made at a lower level. The 1837 man engine at the Samson Pit in Sankt Andreasberg in the same region is still in use, although converted from water to electric power in 1922.