THE INTELLECTUAL RISE IN ELECTRICITY. 



twenty ounces; and he describes other experiments, all 

 going to show the increased lifting power gained by the 

 attachment of the armature. Galileo, it seems, for the 

 purpose of repeating Gilbert's experiments, had prepared 



GAUGED 



for himself a lodestone weighing about half a pound Tus- 

 can, and this the duke wanted. Galileo thereupon wrote 

 to the ducal secretary, stating that while everything that 

 he owned was at the disposal of his sovereign, he ventured 



'Reduced fac simile of the frontispiece of his vSystema Cosmicum. 

 Ley den, 1641. 



