sentences:  These show that in a span of less than 50 years (1788 to 1825), the population grew more than twofold.This growth arose not only from natural growth, but also from a change in economic conditions, namely the expansion of mercury mining on the Potzberg.This mining expansion might partly explain the peak in Föckelberg's population of 444 in 1905, although by that time, most of the mines on the mountain had been shut down.