Galileo Galilei to the biography by Vincenzo Viviani) that these began by watching the swings of the bronze chandelier in the cathedral of Pisa, using his pulse as a timer. Later experiments are described in his "Two New Sciences". Galileo claimed that a simple pendulum is isochronous, i.e. that its swings always take the same amount of time, independently of the amplitude. In fact, this is only approximately true, as was discovered by Christiaan Huygens. Galileo also found that the square of the period varies directly with the length of the pendulum. Galileo's son, Vincenzo, sketched a clock based on his father's
Italian submarine Galileo Galilei machine guns. "Galileo Galilei" was built at Tosi shipyard at Taranto. She was launched on March 19, 1934 and commissioned on October 16 of the same year . After delivery, "Galileo Galilei" together with other submarines of "Archimede"-class was assigned to 12th Squadron of the III Flotilla, later to become 41st and then 44th Submarine Squadron of the VII Submarine Group, based at Taranto. After a period of intensive training and short cruises, the Squadron was sent for training to Tobruk. In 1937, along with many other submarines of the Royal Italian Navy ("Regia Marina"), "Galileo Galilei" secretly participated in