fuch may be found very compendiouny {as h faith) and wkh 
fai greater difpatch,than hath'been doiie by fome others, efpe- 
* cially the Author of the Clavls^Geometria. The like he under- 
takes to do, and that more largely, of Harmonical Proportions, 
concerning which he gives^us the Deiiionftration oi ten Pro. 
bUms of that kind, whofe Truth he had found out by the Me- 
thod of t\ieAmlyp fpeciofa^thereby tolhew to the Intelligent, 
how great a difference there is between thefetwo wayes, for 
fliortnefs, pcrfpicuity, pleafantnefs^andeafe to the memory Jn 
this piece alfo theAuthor makes mention of divers things about 
the ConJlrHltm of^quation5?,left imperfeft by Fkrimundu^ de 
Beaune^whichhG (our Author) promifed to publifli with the 
Tradi that is abroad, arid known by the Title of the Second 
Part of Des-Cmes^s Geometry ; in which indeed he treats de 
Naturac^' Con^itutune tL/Equationufn^ & de Limitibus^ but no- 
thingof the Geometrical Conjlru^ions^ either his own^or thofe 
that remained iriiperfeft of thefaid De J3^^»»^,mention'd to be 
in his (our Authors) cuftody. So much of the JirJlTxz&, 
: 'T:htfecond\s>\\\s Diori/iiceim which having takennotice^how 
libort the Antient Geometricans came of a General Art of Deter 
mining Problems, he faith, he hath endeavoured to fupply that 
defeft, by delivering here two G^'/^fr^i Rules of Determining 
the Limits of liquations, fo as to know, how many Roots are 
poflible: In thefirftofwhich heforowsthe Rule of that fa- 
mous Geometrician F-fm^^": IntYicfecond^ he agrees with the 
* Method of the Learn'd Huddcnim^ to be met with in the ^;;- 
nexa to the firft Part of Des Cartes\ Geometry ; which feems 
indeed to be a Corollary of theExcellent his General 
Method of tangents, publifiit in N^. 90. of thefe Tradis. At the 
end of this piece the Author pronvifeth his Syjfema t!Mathefeos 
Univerfalis^ where he would have the Reader expefl a large ac- 
count of all things belonging to the Analyjis fpmofa,hoth as to. 
Precepts and Examples ; Which promife 'tis hoped will be 
made good by him ere long. 
The third is an AuStarium trigonometria^lo fol ve and demon- 
ftrate Triangles both Reftilinear and Spherical; delivered in 
Xlir. Propofitions, of which he lliews the laft of all to be of 
great life in Tables Aftronomical compofed after the manner of 
* the Rudolphin made hy Kfpler^ where the Diftance of the Sun 
from the Earth, as alfo from aiiy^ot her Planet^ is expreft in Lo- 
'0 ^ o..:')l r' " . gsiritbmes. 
