_Kepler's Birth in 1571--His Family--And early Education--The Distresses and Poverty of his Family--He enters the Monastic School of Maulbronn--And is admitted into the University of Tubingen, where he distinguishes himself, and takes his Degrees--He is appointed Professor of Astronomy and Greek in 1594--His first speculations on the Orbits of the Planets--Account of their Progress and Failure--His "Cosmographical Mystery" published--He Marries a Widow in 1597--Religious troubles at Gratz--He retires from thence to Hungary--Visits Tycho at Prague in 1600--Returns to Gratz, which he again quits for Prague--He is taken Ill on the road--Is appointed Tycho's Assistant in 1601--Succeeds Tycho as Imperial Mathematician--His Work on the New Star of 1604--Singular specimen of it._ It is a remarkable circumstance in the history of science, that astronomy should have been cultivated at the same time by three such distinguished men as Tycho, Kepler, and Galileo. While Tycho, in the 54th year of his age, was observing the heavens at Prague, Kepler, only 30 years old, was applying his wild genius to the determination of the orbit of Mars, and Galileo, at the age of 36, was about to direct the telescope to the unexplored regions of space. The diversity of gifts which Providence assigned to these three philosophers was no less remarkable. Tycho was destined to lay the foundation of modern astronomy, by a vast series of accurate observations made with the largest and the finest instruments; it was the proud lot of Kepler to deduce the laws of the planetary orbits from the observations of his predecessors; while Galileo enjoyed the more dazzling honour of discovering by the telescope new celestial bodies, and new systems of worlds. John Kepler, the youngest of this illustrious band, was born at the imperial city of Weil, in the duchy of Wirtemberg, on the 21st December 1571. His parents, Henry Kepler and Catherine Guldenmann, were both of noble family, but had been reduced to indigence by their own bad conduct. Henry Kepler had been long in the service of the Duke of Wirtemberg as a petty officer, and in that capacity had wasted his fortune. Upon setting out for the army, he left his wife in a state of pregnancy; and, at the end of seven months, she gave premature birth to John Kepler, who was, from this cause, a sickly child during the first years of his life. Being obliged to join the army in the Netherlands, his wife followed him into the field, and left her son, then five years old, under the charge of his grandfather at Limberg. Sometime afterwards he was attacked with the smallpox, and having with difficulty recovered from this severe malady, he was sent to school in 1577.