ON INSTRUMENTS FROM ITAL Y. 119 



fluous, since you yourselves, starting from this new principle that 

 the pendulum, moving through greater or lesser spaces, always makes 

 its reciprocating motions perfectly equal; you, I say, will deduce 

 much more ingenious and sublime consequences than I can possibly 

 imagine." 



From this we gather that the first clock with a pendulum made by 

 Galileo differed essentially from ours, inasmuch as the wheelworks 

 were moved by the pendulum, which made it necessary for some one 

 to impart a new impulse to it as soon as it was about to stop. If no 

 olher document existed in favour of Galileo, it would seem to me to 

 be more than enough to secure the first place for him, with regard 

 likewise to the application of the pendulum to clocks. The essence 

 of the invention lies, of course, in the first idea, and we have here, 

 moreover, an instrument that works very well. 



But in Galileo's lofty mind it was impossible but that the thought 

 should flash of making the motion itself of the clock maintain that of 

 the pendulum, which would thus be reduced to a simple regulator. 

 Not to draw out this lecture to 'too great a length, I shall only quote 

 what Viviani wrote upon this subject for Prince Leopoldo de' Medici. 

 In that account, after having described Galileo's experiments on the 

 pendulum and the manner in which he applied it to the measurement 

 of time, he proceeds thus : 



" But as Galileo was most liberal in communicating his inexhaustible 

 speculations, it frequently happened that the uses and newly dis- 

 covered properties of his pendulum, spreading little by little, fell into 

 the hands of persons who adopted them for their own purposes, or 

 inserted them into publications, and by artfully passing in silence over 

 the name of their true author, made such use of them that it was 

 believed at least by those who knew nothing of the origin of the dis- 

 coveries that the writers were the real authors of them." He next 

 speaks of the observations of the " Stelle Medicee," of the tables rela- 

 ting to them prepared by the Padre Renieri, of the offering made by 

 Galileo to the States-General of Holland of his method for determining 

 longitudes by means of the eclipses of Jupiter's satellites, and of 

 Galileo's determination to send his son Vincenzo and the aforesaid 

 Padre to Holland, since he himself, being old and blind, was unable 

 to travel thither. He then continues : " While, therefore, Padre 



