Italian researchers have unearthed a marble benchmark which was once used to measure the shape of Earth in the 19th century.

Called Benchmark B, the marker was found near the town of Frattocchie along one of the earliest Roman roads which links the Eternal City to the southern city of Brindisi.

Placed there by Father Angelo Secchi (1818-1878), a pioneer of astrophysics, the marker consisted of a small travertine slab with a metallic plate in the middle. The plate featured a hole at its center....