GALILEI, Galileo (1564-1642). Istoria e dimostrazioni intorno alle macchie solari e loro accidenti. Rome: Giacomo Mascardi, 1613.

Lovely and fresh first edition of Galileo’s work on sunspots and first published endorsement of the Copernican model, transalpine issue without the reprint of Christoph Scheiner's letters to Marcus Welser. Galileo wrote his Istoria e dimostrazioni in the form of letters to Welser, arguing that sunspots appeared on the surface of the sun and were not tiny satellites of it. Based on observations of their motion, Galileo concluded that the sun rotated on a fixed axis. The work also includes Galileo's first written account of his observations of the phases of Venus and the mysteries of Saturn. His specific endorsement of the Copernican model foreshadowed many of his later theories and their political and religious consequences: "I tell you that this planet also, perhaps no less than horned Venus, agrees admirably with the great Copernican system on which propitious winds now universally are seen to blow." The two issues were published simultaneously, with and without Scheiner's letters to Welser, aimed at a domestic or international market respectively. As Scheiner was then teaching at Ingolstadt, the printer Mascardi felt free to publish his letters in Italy, but north of the Alps privileges would be infringed. Cinti 43; Carli and Favaro 60; Riccardi I, 509 ("raro"). Exhibited: "The Heavens Revealed," Chapin Library, Williams College, 2003.

Quarto (222 x 154mm). Woodcut Lincei device on title, engraved portrait of Galileo, 38 full-page engravings of sunspots, 5 full-page engravings of Jovian satellites, one engraving and several woodcut and typographic diagrams in text (very few spots). Later vellum, title gilt-stamped on spine (a few repairs to boards, yellowed). Cloth box.