GALILEO. b 



number 10 is oftener thrown than the number 9. Galileo makes 

 a careful and accurate analysis of all the cases which can occur, 

 and he shows that out of 216 possible cases 27 are favourable 

 to the appearance of the number 10, and 25 are favourable to the 

 appearance of the number 9. 



The piece will be found in Vol. xiv. pages 293 — 290, of Le 



Opere cU Galileo Galilei, Firenze, 1855. From the Biblio- 



grafia Galileiana given in Vol. XV. of this edition of Galileo's 

 works we learn that the piece first aj^peared in the edition of the 

 works published at Florence in 1718 : here it occurs in Vol. III. 

 pages 119 — 121. 



9. Libri in his Histoire des Sciences Mathematiques en Italie, 

 Vol. IV. page 288, has the following remark relating to Galileo : 

 ..."Ton voit, par ses lettres, qu'il s'etait longtemps occupe d'une 

 question delicate et non encore resolue, relative h, la maniere de 

 compter les erreurs en raison geometrique ou en proportion 

 arithm^tique, question qui touche ^galement au calcul des pro- 

 babilites et a Tarithmetique politique." Libri refers to Vol. ii. 

 page 00, of the edition of Galileo's works published at Florence 

 in 1718 ; there can, however, be no doubt, that he means Vol. iii. 

 The letters will be found in Vol. xiv. pages 231 — 284' of Le 

 Opere... di Galileo Galilei, Firenze, 1855 ; they are entitled Lettere 

 intorno la stwia di un cavallo. We are informed that in those 

 days the Florentine gentlemen, instead of wasting their time 

 in attention to ladies, or in the stables, or in excessive eraminfr. 

 were accustomed to improve themselves by learned conversation 

 in cultivated society. In one of their meetings the following 

 question was proposed ; a horse is really worth a hundred crowns, 

 one person estimated it at ten crowns and another at a thousand ; 

 which of the two made the more extra vagrant estimate ? Amoncr 

 the persons who were consulted was Galileo ; he pronounced the 

 two estimates to be equally extravagant, because the ratio of a 

 thousand to a hundred is the same as the ratio of a hundred to 

 ten. On the other hand, a priest named Nozzolini, who was also 

 consulted, pronounced the higher estimate to be more extravagant 

 than the other, because the excess of a thousand above a hundred 

 is gi'eater than that of a hundred above ten. Various letters of 



