Check out this Official Postcrossing card from Germany! Right in the middle of the country (well, maybe slightly north of the center) lies this town – Goslar, a town of over a thousand years and home to two UNESCO World Heritage sites (the Old Town and the Mines of Rammelsberg). This town sits just northwest of a mountain range known as the Harz, where for nearly a millennium people mined for copper, lead and tin in. Thanks to the Upper Harz Water Regale – an extensive water management system using things like dams and reservoirs – miners were provided a source of energy to help with the excavation process. Lemme talk about this, ‘cause I thought this was kinda cool! One of the biggest obstacles for miners was the heavy amount of underground water, which made excavating really tough. They decided to install a water wheel in the mines, and with the water management system, streams were diverted to power that water wheel (that in turn powered reciprocating pumps) and raise the underground water out. Without getting too technical, a reciprocating pump draws water from below using a piston,that gets pushed into an outlet above. That piston, I believe, would get powered by the water wheel. So in short – it’s fighting water with water! Anyway, that was way too much detail on that… but I wanted to flaunt the fruits of my research. This here on the card is the Imperial Palace of Goslar, also known as Kaiserpfalz, which served as the residence of many Holy Roman Emperors (the Holy Roman Empire was a large territory encompassing a number of countries – including modern-day Germany – from 962 to 1806). I’m a bit spent on all the research on reciprocating pumps, so I think I’ll leave it at that. Thank you lots for sending me this neat postcard! I’m PUMPED!