The fame of our author as an astronomer and mathematician was now so high, that several young Danish nobles requested him to deliver a course of lectures upon these interesting subjects. This application was seconded by Pratensis, Danzeus, and all his best friends; but their solicitations were vain. The King at last made the request in a way which ensured its being granted, and Tycho delivered a course of lectures, in which he not only gave a full view of the science of astronomy, but defended and explained all the reveries of astrology. Having finished his lectures, and arranged his domestic affairs, he set out on his projected journey about the beginning of the spring of 1575, leaving behind him his wife and daughter, till he should fix upon a place of permanent residence. The first town which he visited was Hesse-Cassel, the residence of William, Landgrave of Hesse, whose patronage of astronomy, and whose skill in making celestial observations, have immortalized his name. Here Tycho spent eight or ten delightful days, during which the two astronomers were occupied one half of the day in scientific conversation, and the other half in astronomical observations; and he would have prolonged a visit which gave him so much pleasure, had not the death of one of the Landgrave's daughters interrupted their labours. Passing through Frankfort, Tycho went into Switzerland; and, after visiting many cities on his way, he fixed upon Basle as a place of residence, not only from its centrical position, but from the salubrity of the air, and the cheapness of living. From Switzerland he went to Venice, and, in returning through Germany, he came to Ratisbon, at the time of the congress, which had been called together on the 1st of November, for the coronation of the Emperor Rudolph. On this occasion he met with several distinguished individuals, who were not only skilled in astronomy, but who were among its warmest patrons. From Ratisbon he passed to Saalfeld, and thence to Wittemburg, where he saw the parallactic instruments and the wooden quadrant which had been used by John Pratensis in determining the latitude of the city, and in measuring the altitudes of the new star. Tycho was now impatient for home, and he lost no time in returning to Denmark, where events were awaiting him which frustrated all his schemes, by placing him in the most favourable situation for promoting his own happiness, and advancing the interests of astronomy. CHAPTER II.