JEROME CARDAN 91 



to begin to quibble with his conscience. On May 12, 

 1539, he wrote another letter to Tartaglia, also in a very 

 friendly tone, reproaching him gently for his suspicions, 

 and sending a copy of the Practice of Arithmetic to 

 show him that they were groundless. He protested 

 that Tartaglia might search from beginning to end 

 without finding any trace of his jealously-guarded rules, 

 inasmuch as, beyond correcting a few errors, the writer 

 had only carried Algebra to the point where Fra Luca 

 had left it. Tartaglia searched, and though he could not 

 put his finger on any spot which showed that Messer 

 Hieronimo had broken his oath, he found what must 

 have been to him as a precious jewel, to wit a mistake 

 in reckoning, which he reported to Cardan in these 

 words : 



" In this process your excellency has made such a 

 'gross mistake that I am amazed thereat, forasmuch as 

 any man with half an eye must have seen it indeed, if 

 you had not gone on to repeat it in divers examples, I 

 should have set it down to a mistake of the printer." 

 After pointing out to Cardan the blunders aforesaid, 

 he concludes : " The whole of this work of yours is 

 ridiculous and inaccurate, a performance which makes 

 me tremble for your good name." l 



Every succeeding page of Tartaglia's notes shows 

 more and more clearly that he was smarting under a 

 sense of his own folly in having divulged his secret. 

 Night and day he brooded over his excess of confidence, 

 and as time went by he let his suspicions of Cardan 

 grow into savage resentment. His ears were open to 

 every rumour which might pass from one class-room to 

 another. On July 10 a letter came to him from one 

 Maphio of Bergamo, a former pupil, telling how Cardan 

 1 Quesiti et Inventioni^ p. 125. 



