Theorema Harriotti, de numero radicum verarum et falsarum [...] A. M DCC XX[X]. die XVIII. aprilis.

4to: [2]-44 pp.

Sewn with paper strip on spine. Excellent wide-margined copy.

Rare original ed. of an influential treatise by the young Leipzig scholar F.W. Stübner (1710-1736) on the negative and complex roots of equations, as formulated by the English mathematician Thomas Harriot (1560-1621). Ref. H. Schröder (Der Fundamentalsatz der Algebra, 2017) 467. - Not in VD-18, BL. Joined: Carstens, Joachim – Tractatio academica de errore calculi, ad L. un. C. eod. & concord. exercitij gratia, methodice exhibita. Greifswald, J. Albinus, 1623. 4to: [8] ff. (toned). Disbound. Very good copy. On a calculation error in Roman law, by the German lawyer, and later "syndicus" of Lübeck, Joachim Carstens/Kerstens (1596-1673). Ref. VD-17 7:654042V (Göttingen copy only). Prov. Libr. stamp. (2 vols)