DESCARTES, René. Musicae Compendium, Amsterdam: Blaviana, 1683, 4°, engraved vignette to title, woodcut illustrations (good copy with wide margins, slightly browned & spotted), modern vellum. [Guibert, p. 187] -- Claudius PTOLOMAEUS (circa A.D. 100- A.D. 170). Harmonicorum libri tres... Oxford: E Theatro Sheldoniano, 1682, 4°, frontispiece, 2 engraved plates, engraved vignette, several illustrations (leaves browned throughout, margins brittle, inner hinge of first few leaves reinforced, some leaves loose), contemporary calf (rebacked, front cover detached, scuffed). [Wing P4149] Provenance: C.W. Seidenadel (2)