MEMOIR OF GALILEO. 87 



some it was set down as a meteor ; but from the absence of 

 parallax, Galileo proved it to be one of the fixed stars, sit- 

 uated far beyond the bounds of our own system. 



Galileo was again appointed professor at Padua, in 1606, 

 and his salary increased to 520 florins. So great had his 

 fame as a philosopher arisen, that the lecture-room could not 

 contain his hearers, which obliged him often to lecture in the 

 open air. Among other pursuits, he investigated the prop- 

 erties of the loadstone, and discovered a method of arming 

 them, so as to double their magnetic power. Galileo still 

 kept up communication with the family of the Duke of 

 Tuscany, who had been his early patron. Cosmo, who had 

 succeeded his father Ferdinand, had been one of Galileo's 

 pupils, and being imbued with an ardent wish to promote 

 science, formed the desire of attaching his former master to 

 his household. Negotiations were accordingly commenced. 

 His salary, as professor at Padua, was to be greatly in- 

 creased on the expiry of his engagement. The seclusion of 

 private life, however, offered far greater charms to the studi- 

 ous philosopher. He was anxious to escape the performance 

 of public and private duties, which continually interrupted 

 his own studies. He accordingly accepted the situation of 

 philosopher and principal mathematician to the Grand Duke 

 of Tuscany, with a salary of 1000 florins, and took uf) 

 his residence at Florence. The only duties attached to this 

 situation, were, to lecture occasionally to sovereign princes. 

 It was expressly stipulated that he should have the most 

 perfect command of his own time, to devote to study and 

 the completion of some projected works. 



During the progress of the arrangements for leaving Padua, 

 Galileo paid a visit to Venice. Here he became informed of 

 an optical instrument, presented by a Dutchman to Prince 

 Maurice of Nassau, which possessed the property of enlarging 

 objects, and bringing them nearer the observer. This was 

 confirmed by a letter which Galileo received a few days af- 



