XIV PREFACE. 



graphy than the history of science ; and yet we think 

 that they will be acceptable to the lover of familiar 

 history. Similar remarks may be made of others*. 



In the appendix to Dr. Vaughan's ''Protectorate 

 of Oliver Cromwell," are printed several letters from 

 Pell's MS. collections, a few of which we have found 

 it necessary to reprint in this work. Unfortunately 

 no references whatever are given to the places whence 

 these letters are taken, and amidst the very numerous 

 volumes which compose Pell's collections, it is no 

 easy matter to find the deposit of any particular one. 

 Owing to this arrangement, we have been quite un- 

 able, although we have spared no exertions, to find the 

 original of a very curious letter which Dr. Vaughan 

 has printed at p. 347. It is written by Dr. Pell, and 

 dated Oct. 12th, 1642; and we are unwilling to 

 neglect the opportunity of extracting the following 

 passage : 



" I can hear of nothing of Vieta's in manuscript in England, 

 but such pieces of his as are already printed, and were trans- 

 cribed for the most part out of the printed books, because 

 they could not be had for money. Here is also a manuscript 

 of his no tee prior es ad logisticen speciosam, transcribed many 

 years ago at Paris out of a written copy ; but since that time, 

 le Sieur de Beaugrand hath caused it to be printed in 24mo. 

 at Paris, anno 1631, with a few notes of his own thereon. It 



* We have neglected to say in the proper place (p. 31), that " a 

 copie of the speache made by the mathematicall lecturer unto the 

 worshipfull company present, at the house of the worshipfull Mr. 

 Thomas Smith," was published at London in 1588, small 4to. From 

 the title-page to his treatise on the Cross-staf, it appears that Hood 

 was mathematical lecturer in 1596 ; but in his work on the Sector, 

 published in 1598, this title is omitted. We also omitted to remark, 

 that from MS. Harl. 7523, fol. 206, it appears that Pell in 1650 had 

 a design of publishing commentaries on the works of Descartes. 



