Copperplate engravings, mm 365x425 each. Uncommon planisphere in two separate sheets, enriched by the usual allegorical depictions of the seasons in the lower corners with related zodiac signs in the upper corners, affixed above the title, which follows on tape the sphericity of the hemispheres. Taken from the first and only edition" Specula Physico-Mathematico-Historica" by Zahn, a very rare work of encyclopedic character. Very good condition. Copperplate engravings, mm 365x425 each. Uncommon planisphere in two separate sheets, enriched by the usual allegorical depictions of the seasons in the lower corners with related zodiac signs in the upper corners, affixed above the title, which follows on tape the sphericity of the hemispheres. Taken from Specula Physico-Mathematico-Historica. Very good condition. German monk Zahn (1641-1707) belonged to the order of Premonstratensian canons of Herbipolis (present-day Würzburg) and was a pupil of Kircher. He was the author of numerous optical studies, as well as a popularizer of culture in multiple fields. He conceived and created the camera obscura as it would be applied in his concept to the first cameras. Brunet V, 1519: "ouvrage qui n'est aujourd'hui qu'un object de simple curiosité; les exemplaires n'en sont pas communs [...]"; Shirley 583 & 584.