Struve Geodetic Arc
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How it came to be
To find the exact size and shape of the Earth, Friedrich Georg Wilhelm Struve, an astronomer at the University of Dorpat, now Tartu in Estonia, began a triangulation survey in 1816. The work lasted until 1855 and linked more than 2,820 km from near Hammerfest in Norway to the Black Sea through 258 main triangles and 265 main station points. It produced the first accurate measurement of a meridian arc.
At the time the arc passed through only three countries, Norway, Sweden and the Russian Empire. Several surveyors worked under Struve's direction, and the stations were marked by holes drilled in rock, iron crosses, cairns and obelisks. In 1839 Struve founded and became director of the new Pulkovo Observatory near St Petersburg.
In 2005, 34 of the station points, all established between 1816 and 1851, were inscribed as a World Heritage site spread over ten countries: Norway, Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Belarus, Moldova and Ukraine. The first point of the arc is at the old observatory in Tartu.
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