(.719) 
for that which cannot be found. He delivers alfo a method of 
drawing Touch-lines to all the Conick SeEions^ and divers other 
Curves > concerning which, the Author fpeaking of Apelknius^ 
faith 5 
Siquis iffius Conftruftionem, at qui > demonjlrationem 34. prop, 
1. lib. Conicorum cum noftris comparabit, nonnihil fortafle froficief 
in Arte dilatandi Propofiiiones $ > Bemonjlratiows. Nam quod 'Me 
de Q^ldxmcztantum Hyperbole, Ellipfi, & Circulo (latmt, Nos 
ad omnes forrigimus Hyperbolas? Ellipfes Circulofque Infinites: 
And p. 12. the like for infinite Parabolas: And thefe are fome 
of thofe matters handled by the Author, which ^,7. he affirms to 
be of excellent ufe 5 Ad inveniendas plurium UnearumTangentes> 
fgurarum Centra gravitatis & guadraturas : Herein, agreeing 
with des* Cartes in his Geometry, ^.40. where fpeaking of the 
fame matter, he faith 5 Nec vereber dicer e y Problema hoc nonce- 
rum modoj qu<efcio } utilifimum $ gene rait ffimum effe, fed etiam' 
eorum> qua in Geometria fcireunquam defideraverim. 
This excellent Author promifeth fome other- Treatifes in hi:/ 
Preface to an Abbot, where he faith 5 
Si hoc affequar, ut tibi c &ter is que amicis, earundem difciplinarum 
intelligentibuSy probetur, minus erit tmpoflerum, quam cb rem hu- 
manifsimis tuis hortationibus obluffer^ cum Author mihi effe per [eve- 
rabis edendi alia, qua tecum] ampr idem pommunicavi^ de Precept is , 
univerfe Aft is Analytics Geometrica methodo breviter cjr- ex--' 
pedite demon jlratis, ma cum Animadverfione Erratorum } qu& w 
iffis trade ndis nugnt nominis Kuthores err off e deprehendi 3 faci- 
Uusque obtinebis^ ne dmtiuspremam apjidme^qu&cunque deGeomt- 
tria di[putaia 7 & Uteris confignata } in cert as redegi Propofiiiones > 
fjrex his Mam prdcipue a Torricellio & a Te quoq^ t ant of ere com- 
mendatam^ qua mtegram doBfinam 30. Propofitionum Archimedis, 
Luca? Valerii, & aliorum, una compktiitur. Befides, he promi- - 
ieth (which matter yet hath already been well handled by La Lo- 
ver a in his Element a tetragOnifmicjy Tolofe, A. 155 r. and by 
Hugenius m the fame year in a fmallTraft, intitul'd iheoremata- 
de guadratura Hyperboles, Hlipfis^ & Circuit, ex date portionum 
gravitatis centro^) duos alias*, quibus tot am pern J. Caroli dela 
FaiHe, de Centro gravitatis par Hum Circtdi^& Ellipses doctrinam 
Quftpvol. ah ipfo explicatam*) abfolvv. 
But then, ^7. he ^xomikti\^ufiumopm^ ubiddimtis mvam 
lid&ftm^ 
