XEE4139834 Gas pressure: atmospheric pressure. On the left, the experiment of Evangelista Torricelli (or Toricelli) on the atmospheric pressure measured using his Barometre (mercury tube) in 1643. On the right, the experience of Blaise Pascal (1623-1662) made at the Tour Saint Jacques (Saint-Jacques) in Paris with a tube of Torricelli. Anonymous illustration from 1925. Private collection. by Anonymous; Private Collection; (add.info.: Gas pressure: atmospheric pressure. On the left, the experiment of Evangelista Torricelli (or Toricelli) on the atmospheric pressure measured using his Barometre (mercury tube) in 1643. On the right, the experience of Blaise Pascal (1623-1662) made at the Tour Saint Jacques (Saint-Jacques) in Paris with a tube of Torricelli. Anonymous illustration from 1925. Private collection.); Stefano Bianchetti; out of copyright.