[iior] 
Of this treatife here is the fuller account inferted, be- 
Gaufe the Book it felf hath beenbuc little kaown abroad,- 
that it may hence appear to what eftate Harriot: h^id. 
brought y^/^^^r^ before his death. 
After this follows an account of Dr. Felfs method, 
who hath a particular way of Notation, by kee,ping a Re- 
gifter (in the Margin) of the feverail Steps in his Demon- 
ftrations, with References from one to another. . 
Of this, lome Examples are here inferted of his own^ 
and others in imitation thereof; with intimation how 
that innumerable Solutions of Undetermined Cafes are 
by his method eafily dilcoverable, where great Mathe- 
maticians have thought ita great work to find out fome 
one. 
On this occafion there is a farther Dikomk oiVride- 
ter mined Sluejlons ^ and the Limitation of them, and 
particularly of the Rule of .^Zf^^^^/V^z i and of (what they 
callj Geometrical Places ; which are of a like nature, and 
but the Geometrical Conftrudlion of (fome of) theie Un- 
determined Queftions. 
After this is a Diicomteol Negative S^t^ares, and the 
Roots of them i on which depend (what they call) Ima" 
ginary I^ots of Impoffible Equations ; ftiewing, what is 
the true Import thereof in nature, with divers Geometri- 
cal Conftrudions fuiting thereunto. 
And here alfo (though by way of Digreffion, as to the 
principal Subjed) is account given of ieveral Geometri- 
cal Conflrudions, not only of ^adraticki but even of 
Cubick^ndBiquadratick^^c^nz.txon'B. 
Then follows a Difcourfe of the method of Exhaujlions 
(ufed by Ancients and Moderns,^ with the foundation, 
of it. 
And in purfuance thereof, the Geometria fydiviji-* 
bilium oiCavalerius s fliewing the true import thereof, 
and its agreement v/ith the Ancients method of Exhau- 
ilionsi as being but a compendious Expreffion thereof, 
and 
