(but elder than he, and died before him, ) and left many 
good things behind him in writing. Ot which there is 
nothing hitherto made publick, but only his -^/^^im or 
AnalyticBy which was publiflied by Mr. Warner, foon after 
that of Mr. Oughtred, in the fame Year 
He alters the way of Notation, ufed by Vteta and Ou^*- 
tred, for another more convenient. 
And he hath alfo made a ftrange improvement of y^/- 
^ebra^hj difcQvering the true conftruition of Compound £- 
quations,^ how they may be railed by a Multiplication of 
Simple Equations, and may therefore be relolved into fuch. 
By this means he fliews the number of Roots (real or 
imiiginary ) in every Equation, and the Ingredients of 
all the Coefficients, in each degree of Affedion. 
He fliews alfo how to increafe or diminifli the IR^ots 
(yet unknown) by any Excels, or in any Proportion af- 
iigned ; to deftroy fomeof the intermediate Terms; to 
turn Negative Roots into Affirmative, or thele into 
thole; withmanyother things very advantagious in the 
practice of Algebra, 
And amongft other things, teacheth (thereby) to re- 
folve, not only ^imdratic\s, but all T^^i^V/^ Equations ^ 
even thofe whole Roots have, by others, been thought 
Inexplicable, 2ind hut Imaginary. 
In fum. He hath taught (in a manner^ all that which 
hath fiace pafTed for the Cartefian method of Algebra ; 
there being fcarce any thing of (pure) Algebra in Des Car" 
tes, which was not before in Harriot ; from whom Des 
Cartes feems to have taken what he hath ( that is purely 
Algebra) but without naming him. 
But the Application thereof to Geometry, or other par- 
ticular Subjedrs, (which D^j- Cartes purines,) is not the 
bufinefsof that Treatile of Harriot, (but what he hath 
handled in other Writings of his, which have not yet 
the good hap to be made paMick J the defign of this be- 
ing purely Algebra^ abftrad from particular Subjeds. 
