240 JEROME CARDAN. 



of which four instruments you will give two to his excel- 

 lency the lord marquis, and the other two keep as your 

 own. 



It was practically an important gain to Tartalea, if he 

 could suggest, through any friend who would get for 

 them proper attention, a knowledge of his inventions to 

 a military chief able if he chose to bring them into use 

 and notice. The complaints made by Tartalea have led 

 to the supposition that Cardan made artful use of the 

 name and influence of his patron, in a deep design for 

 the wresting from Nicolo of the small bit of knowledge 

 he desired to get 1 . The supposition is quite incorrect. 



1 In Button's Mathematical Dictionary the spirit of the next letters 

 between Cardan and Tartalea is expressed in the following manner, 

 and it is the usual version of the story: "Finding he could not thus 

 prevail with all his fair promises, Cardan then fell upon another scheme. 

 There was a certain Marquis dal Vasto, a great patron of Cardan, and, 

 it was said, of learned men in general. Cardan conceived the idea of 

 making use of the influence of this nobleman to draw Tartalea to Milan, 

 hoping that then, by personal entreaties, he should succeed in drawing 

 the long- concealed rules from him. Accordingly, he wrote a second 

 letter to Tartalea, much in the same strain with the former, strongly 

 inviting him to come and spend a few days in his house at Milan, and 

 representing that, having often commended him in the highest terms 

 to the marquis, this nobleman desired much to see him ; for which 

 reason Cardan advised him, as a friend, to come and visit them at 

 Milan, as it might be greatly to his interest, the marquis being very 

 liberal and bountiful; and he besides gave Tartalea to understand, that 

 it might be dangerous to offend such a man by refusing to come, who 

 might, in that case, take offence, and do him some injury. This 



manoeuvre had the desired effect " Button's Philosophical and 



Mathematical Dictionary (ed. 1815), vol. i. p. 81. So the tale is gene- 

 rally told against Cardan. From his entire letter which follows, and 

 the rest of the story as narrated in the text, the reader may judge how 

 far this version is a fair one. 



