A great deal of misconception has hitherto prevailed respecting Hariot’s great printed work on Algebra. His reputation as a mathematician has been permitted to hinge chiefly upon it, very much to his disadvantage. A brief bibliographical statement of facts will probably present the matter in a new light. But first let the book be described as it lies before us and has been described by many others since the days of Professor Wallis, nearly two hundred years ago. The Title is as follows : ‘Artis Analyticæ / Praxis / Ad æquationes Algebraicas nouæ, expeditæ, & generali / methodo, resoluendas : / Tractatus/ E posthumis THOMÆ HARRIOTI Philosophi ac Mathematici ce- / leberrimi sche-diasmatis summæ fide & diligentia / descriptus:/ Et/Illvstrissimo Domino/Dom. HenricoPercio,/ Northvmbriæ Comiti,/Qui hæc primò, sub Patronatus & Munificentiæ suæ auspicjss / ad proprios vsus elucubrata, in communem Mathematicorum / vtilitatem, denuò reuisenda, describenda, & publicanda / mandauit, meritissimi Honoris ergò / Nuncupatus. / Londini / Apud Robertvm Barker, Typographum / Regium : Et Hæred. Io. Billii. /Anno 1631. / _Title, reverse blank;_ Prefatio 4 pages; Text 180 pages, and Errata 1 page (Bbb) followed by a blank page, folio. A very handsomely printed book. In the British Museum, 529 m 8, is Charles the First’s copy in old calf, gilt edges, with the royal arms on the sides. In the Preface the editors (Aylesbury and Prothero aided by Warner)say: Artis Analyticæ, cuius caufa hîc agitur, port eruditum illud Græcorum fæculum antiquitatæ iamdiù & incultæ iacentis, rcftitutionem _Francifcus Viete,_ Gallus, vir clariflimus, & ob infignem in fcientijs Mathematicis peritiam, Gallicæ gentis decus, primus fingulari confilio & intentato ante hâc conamine aggreffus eft; atque ingenuam hanc animi fui intentionem per varios tractatus, quos in argumenti huius elaboratione eleganter & acutè confcripfit, pofteris teftatem rcliquit. Dùm verò ille veteris Analytices reftitutionem, quam fibi propofuit, feriò molitus eft, non tàm eam reftitutam, quàm proprijs inuentionibus actam & exornatam, tanquam nouam & fuam, nobis tradidifle videtur. Quod generali conceptu enuntiatum paulo fufius explicandum eft; vt, oftenfo eo quod primùm à _Vieta_ in inftituto fuo promouendo actum eft, quid pofteà ab authore noftro doctifiimo _Thomâ Harrioto,_ qui ilium certamine ifto Analytico fequntus eft, praeftitum fit, meliùs innotefcere possit. [Which done into English is substantially as follows]