Meridian stones were used to rectify magnetic pole related deviations in compass gaugings.
The Altenberg meridian stones were set up in 1852 by surveyor Fr. J. Weiß. As the earth’s magnetic pole is always changing slightly, the local meridian was of major importance to miners’ measurements. These slight changes caused the previously common compass measurements to become corrupted. The meridian allows the magnetic deviations to be calculated accurately, and the compass values to be converted to the local coordinates. The meridian’s zero point also constituted the reference point for the local height measurements.
The locations of the zero point stone and the southern meridian stone at the edge of the agricultural areas prevented the stones, which had not been used in mining for many years, from getting lost. Direct lines of sight previously existed between the meridian stones, but this is no longer the case, due to urbanisation in the city of Altenberg. The low, inconspicuous sandstone blocks are part of the local coordinate-network that was used to map the Altenberg mine complex. The meridian’s measurement line consists of three demarcation stones. The zero point stone is located on the Wirtschaftsweg walk above the Neubadstraße street. The southern meridian stone is located in 940 m distance on the Sonnenhofweg walk. The northern meridian stone is 1.520 m away near the Hirschsprung location. Joining the northern and the southern meridian stone yields the Altenberger meridian, which goes along the zero point.