Groma
From NovaRoma
The groma is a surveying instrument.
Sources
Metal parts of a groma were found in Pompei and are now in the Museo Archeologico Nazionale Napoli (Naples National Archaeological Museum).
The tombstone of Lucius Aebutius Faustus (1 c. B.C.E.) in the Museo Civico at Ivrea, Italy show parts of a groma.