Galileo Galilei was born at Pisa on the 18th of February in 1564. His father, Vincenzo Galilei, belonged to a noble family and had gained some distinction as a musician and a mathematician. At an early age, Galileo manifested his ability to learn both mathematical and mechanical types of things, but his parents, wishing to turn him aside from studies which promised no substantial return, steered him toward some sort of medical profession. But this had no effect on Galileo. During his youth he was allowed to follow the path that he wished to. Although in the popular mind Galileo is remembered chiefly as an astronomer, however, the science of mechanics and dynamics pretty much owe their existence to his findings. Before he was twenty, observation of the oscillations of a swinging lamp in the cathedral of Pisa led him to the discovery of the isochronism of the pendulum, which theory he utilized fifty years later in the construction of an astronomical clock. In 1588, an essay on the center of gravity in solids obtained for him the title of the Archimedes of his time, and secured him a teaching spot in the University of Pisa. During the years immediately following, taking advantage of the celebrated leaning tower, he laid the foundation experimentally of the theory of falling bodies and demonstrated the falsity of the peripatetic maxim, which is that an objects rate of descent is proportional to its weight. When he challenged this it made all of the followers of Aristotle extremely angry, they would not except the fact that their leader could have been wrong. Galileo, in result of this and other troubles, found it prudent to quit Pisa and move to Florence, the original home of his family. In Florence he was nominated by the Venetian Senate in 1592 to the chair of mathematics in the University of Padua, which he occupied for eighteen years, with ever-increasing fame. After that he was appointed philosopher and mathematician to the Grand Duk...