484 NOTES. 



but it is remarkable that though Matthew Stewart's Tracts, 

 published in 1761, were known to him, he w r as wholly un- 

 acquainted with the ; Propositions Geometricse,' which 

 appeared soon after, and with the General Theorems which 

 had been published fifteen years before. Nor does he ap- 

 pear to have even seen Professor Play fair's admirable paper 

 upon Porisms in the Edinburgh Transactions, 1794, the 

 war having probably impeded the intercourse of the two 

 countries. Had he seen this, he must have been brought 

 acquainted with the history of the Porism relating to the 

 Comet's place, for it is there fully given. 



It must be added, that Montucla's mathematical pur- 

 suits had for many years been interrupted by the duties of 

 the places which he held under the government, until the 

 Eevolution (Pref. Ill) ; and although the loss of those 

 employments restored him to his studies, it is probable that 

 he rather applied himself to the continuation of the History, 

 the bringing it down from the period to w r hich the first vo- 

 lume extended, than to supply omissions in those volumes, 

 considerable as are the additions which he made to them. 



The third and fourth volumes were not published till 

 after his death, which happened when only a third part 

 of the former had been printed. Lalande undertook the 

 revision of the rest, and how great soever his merits may 

 have been as a practical astronomer, as an author, and a 

 teacher of astronomy, he had none of the mathematical 

 acquirements which could fit him for superintending the 

 publication of Montucla's work. He had some assistance 

 from a very eminent mathematician, Lacroix, and the notes 

 given by him are, as might be expected, excellent. But 

 we are not distinctly informed of the additions, if any, 

 which he made to the text, while there appears considerable 

 reason to suppose, that Lalande sometimes interfered with 

 it. Certain it is, that many things would have been sup- 

 pressed, and others added, had Montucla survived to finish 

 the work of correcting and publishing. There is no reason 

 to think that the eminent analyst referred to (Lacroix), 

 would have supplied Montucla's omissions regarding 

 the Poristic case in the Principia, or regarding the writers 

 on the ancient analysis ; for on this subject he was much 

 better informed, in all probability, than Lacroix, and the 



