r 
AnAccomptof fome Books. 
I. UECHANICA.fwedeMOrvTraeiatur 
Geometricus. Auth. Job. Wallis SS. Th. V. 
^ Geom. Profeff. Saviliano , ^c. Londini ; 
Impenfts Mofis Pit, in Vico 'vocato Little Britain, 
1670. in Quart 0. 
THis Excellent Mathematician/ having compofecP 
a Learned Treatife concerning theDpftrine of 
Motion y and what thereon depends , managing it in a 
manner altogether Geometrical ^ was pleafed , upon 
the importanity of his Friends , to permit the Firfi\ 
Tart thereof to come abroad, whilefl: the others arc 
ftill in the Printers hands j which is about One third 
part of what he did, near two years fince, impart to | 
the K. Society ^ zndi was by them dcfired tpmake it^ 
publick. In this Firft Part he delivers^ - : • ■ v -^r • 
I . The General Rules of Motion , promtlirig there^' 
to, as becomes a ftrid Reafoner and good Geome- 
trician j the Definitions belonging to that Sub)e6}: v 
and then comprifing the Rules themfelves in Thirty 
Propofitions In which be takes occafion, among 
many other weighty particulars, to rntimatc, That it 
is principally thebu^nefsof z Mechanician^ to exco- 
gitate and make practicable fuch Engins , to beinter-- 
pofed between the Strength and the Weighty as may 
lb moderate the Ce/er/>y of MwiWj as to compenfate 
the Greatnefs oi the Weight ^ by the Slownefs of the 1 
Motion^ 
