[Geometry] Beyem van Aerssen, H. Eygenschappen der driehoecken

met een half en anderhalf rechtenhoeck, waer onder verscheydene voorstellen sijn, die de rechthoeckige ende andere driehoecken betreffen. Met noch een tractaet handelende van vierkantighe en deelinghe van verscheydene figuyren door circkelboghen besloten. Leeuw., printed by Schelte Jochems for Eyvo Taecken Wielsma, 1671. Two parts in 1 vol. w. continuous pagination, (8),102,(4); 103-117,(3) p., w. num. woodcut diagrams in the text (diagram on p. 62 pasted in the text), cont. vellum, 4to. A few sm. holes in leaf B2 (trifle affecting the text), partly waterst. in blank upper inner corner. A good copy.

Very rare, hardly ever offered for sale and only a few copies in NCC. Geometry manual by Hippolytus Beyem van Aerssen, only known from this work, devoted to triangles (and some characteristics of rectangles) and geometrical figures within circles, with remarks on the squaring of circles.