A FAITHFUL REPLICA OF TORRICELLI'S EXPERIMENTAL MERCURY BAROMETERPHILIP COLLINS, LATE 20th CENTURYWith two glass tubes set side by side both open at the base and sealed at the top but the right incorporating a bulb, each spended in ogee-shaped open cistern, the apparat mounted via three brackets onto a rectangular oak backboard.98cm (38.5cm) high, 9cm (3.5ins) wide, 11cm (4.25ins) deep.Provenance: The exhibition collection of Barometer World Meum, Merton, Devon.In 1641 the mathematician and scientist Evangelista Torricelli (1608-1647) went to Florence to live and work alongside Galileo who, aged 77, was by thenpletely blind and unfortunately died soon after Torricelli's arrival. On studying his former master's papers Torricelli discovered notes relating to water not being able to be raised any further than around 33 feet with a vacuum pump. On reading this he decided to try the same experiment but with mercury; he soon found that by filling a tube around 36 inches long closed at one end, sealing it with his finger, inverting it and then submersing it into a container filled with mercury before then removing his finger, the level in the tube would then drop to around 29 inches. Torricelli realised that the level of mercury in the tube was being maintained by atmospheric pressure and that this level changed slightly over time. From these experiments in 1643, the first mercury barometer was invented. The present lot is a faithful reconstruction based on Torricelli's illtration reproduced in Banfield, Edwin Antique Barometers, an illtrated survey on page 2 (figure 1.2).