90 LETTERS ON SCIENTIFIC SUBJECTS. 



was indemonstrabile. And though now they begin to feare 

 that it may be demonstrated, yet all the mathematicians in 

 the University of Copenhagen cannot doe it, such shallow 

 artists have I to doe withall. If any of our London ma- 

 thematicians be unwilling or unable to write Latine, let them 



write English, or the catholicke language [a, b, c, H &c.] 5 



and let me alone with the rest. If you want more coppies 

 of my paper, and Mr. Hartlib of Duke's Place cannot furnish 

 you, I shall send you as many as you desire ; or if there be 

 anything else wherein I may serve you, you shall allwayes 

 find me 



Your assured friend and servant, 



JOHN PELL. 

 To his much esteemed freend, Mr. John 



Leake, at his house by the Old Swan 



in Thames Street e, London, these I 



pray. 



SIR WILLIAM PETTY TO JOHN PELL. 



[MS. Birch, Brit. Mus. 4279, fol. 172, Orig.] 



Paris, November 8th, 1645. 



Sir, Father Mersen his desire to convey this inclosed to 

 you, serves me for an happie occasion, to expresse my thank- 

 fulnes for the good of that acquaintance with Mr. Hobs, which 

 your letters procured me for by his meanes, My Lord of 

 Newcastle and your good friend Sir Charles Candish have 

 beene pleased to take notice of mee ; and by his meanes also 

 I became acquainted with Father Mersen, a man who seemes 

 to me not in any meane degree to esteeme you and your 

 works, and who wishes your studies may ever succeede 

 happily, hoping (as others also doe) that the world shall 

 receyve light and benefitt by them. Sir, I desire you not to 

 conceive that any neglect or forgetfulnes hath caused my long 

 silence, for the often speech I have of you either with Sir Charles, 

 Mr. Hobs, & Father Mersen (besides the courtesy I receyved 

 from you) makes me sufficiently to remember you. But, to 

 speake the truth, it was want of buisines worthy to make the 

 subject of a letter of 16P postage, especially since Mr. Hobbs 

 served you in procuring the demonstrations of other french 

 mathematicians. I could wish with Sir Charles that wee 

 could see your way of analyticks abroad, or if a systeme of 

 the whole art were too much to hope for, for my owne part 



