PART I.
GALILEO’S EARLY YEARS, HIS IMPORTANT DISCOVERIES, AND FIRST CONFLICT WITH THE ROMAN CURIA.


CHAPTER I.
EARLY YEARS AND FIRST DISCOVERIES.

Birth at Pisa.—Parentage.—His Father’s Writings on Music.—Galileo destined to be a Cloth Merchant.—Goes to the Convent of Vallombrosa.—Begins to study Medicine.—Goes to the University of Pisa.—Discovery of the Isochronism of the Pendulum.—Stolen Lessons in Mathematics.—His Hydrostatic Scales.—Professorship at Pisa.—Poor Pay.—The Laws of Motion.—John de’ Medici.—Leaves Pisa.—Professorship at Padua.—Writes various Treatises.—The Thermoscope.—Letter to Kepler.—The Copernican System.—“De Revolutionibus Orbium Cœlestium.”

The same memorable day is marked by the setting of one of the most brilliant stars in the firmament of art and the rising of another in the sphere of science, which was to enlighten the world with beams of equal splendour. On the 18th February, 1564, Michael Angelo Buonarotti closed his eyes at Rome, and Galileo Galilei first saw the light at Pisa.

He was the son of the Florentine nobleman, Vincenzo Galilei, and of Julia, one of the ancient family of the Ammanati of Pescia, and was born in wedlock, as the documents of the church clearly attest.[7] His earliest years were spent at Pisa, but his parents soon returned to Florence, which was their settled home. Here he received his early education. His father had distinguished himself by his writings on the theory of music, particularly the mathematical part of it.[8] They were not merely above mediocrity, but aimed at innovation, and if they did not achieve reform, it was to be attributed to the conservative spirit then reigning in Italy, which asserted itself in every department of life, and especially in the spheres of art and science.