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GALILEO GALILEI. 345 



peri m en ts very shortly after their communication to the 



world. 1 The great lawyer who wrote philosophy "like a 

 Lord Chancellor" had already rendered his sarcastic judg- 

 ment upon "Gilbert our countryman," who "hath made 

 a philosophy out of the observations of a lodestone." The 

 greater practitioner of the philosophy of works, writing to 

 the Grand Duchess of Tuscany in 1606, had no compunc- 

 tion in overruling that judgment, and in announcing the 

 advent of a philosophy confirmed by evident demonstra- 

 tions, and "showing our earth to be in its primary and 

 universal substance none other than a great globe of lode- 

 stone." 2 Nor did he ever waver from that opinion. A 

 quarter of a century later it is re-asserted and amplified 

 over pages in the famous Dialogue, which brought him 

 into the clutches of the Inquisition. 3 



In 1607 began a remarkable correspondence 4 between 

 Galileo and the reigning Duke of Tuscany, who had been, 

 and to some extent still was, Galileo's pupil. Of all the 

 magnetic phenomena which Gilbert had recorded, none, 

 saving the theory of the earth's magnetism, appears to have 

 impressed Galileo more strongly than the discoveries of 

 Gilbert concerning the armed lodestone, and especially the 

 notable increase in lifting power which seemed to follow 

 the attachment of the iron helmet or cap to the pole. 

 Gilbert had *said that, by means of this cap or armature, 

 a stone capable of raising but four ounces could be made 

 to raise a weight of twelve ounces, and that when the poles 

 of two such stones thus armed were caused mutually to 

 attract, the joint action of both would lift a weight of 



" Galileo made many experiments upon the magnet, and both he and 

 his favorite pupil, Sagredus, were moved to meditate thereon through 

 having received Gilbert's book." Nelli: Vita, etc., di G. Galileo. Lau- 

 sanne, 1793, i., 103. 



2 Celeste: The Private Life of Galileo. Phila., 1879. 

 * Galileo: Systema Cosmicum, in quo Dialogis, iv.. etc. Ed. Leyden, 

 1641, Dialog, iii., p. 296. 

 4 Opere di G. Galileo. Florence, 1851. 



