Description A compartment of a 16thC brass Torquetum, ø 17,5 cm A torquetum is an instrument, first described by the ancient Greek scientist Ptolemy, which could be used to determine the relative positions of the heavenly bodies and tell the time with some accuracy. Its complex construction allowed it to be adjusted for latitude and date; altitudes were measured against a plumbline on the pendant semicircular flap.A similar piece is depicted in the famous painting 'The Ambassadors' by Hans Holbein the Younger (National Gallery).品相报告: Condition Report Fair condition.