GALILEI, Galileo.

Rare first edition of Galileo’s earliest published endorsement of the Copernican theory. Galileo Galilei (1564-1642) was one of the greatest mathematicians and astronomers of all time. His cutting-edge discoveries revolutionised early modern physics and eventually provoked the famous condemnation of the Holy Inquisition. Amongst many other acknowledgements, he was a member of the prestigious Academy of Lincei, a pioneering scientific fellowship established in Rome by Federico Cesi. Galileo wrote the Istoria e dimostrazione in the form of three letters to his fellow academician Marcus Welser of Augsburg.

Based on telescopic observation of their motion, Galileo concluded that the sun rotated on a fixed axis like the Earth and other planets, thus embracing and somehow overstepping Copernicus’s view. He also insisted that the newly observed sunspots appeared on the surface of the sun and were not its satellites, as the traditional Aristotelian interpretation suggested. In his usual combative tone, he maintained: ‘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…’ His further discovery of the Satellites of Jupiter is described and illustrated with 5 plates. The work also includes Galileo’s first written account of the phases of Venus and Mercury as well as some considerations on the many puzzling mysteries surrounding Saturn. His circumstantial approval of the Copernican model anticipated many of his later theories and the related political and religious consequences.

“Galileo’s letters on sunspots was published at Rome in 1613 under the auspices of the Lincean Academy. In this book Galileo spoke out decisively for the Copernican system for the first time in print. In the same book he found a place for his first published mention of the concept of conservation of angular momentum and an associated inertial concept.” DSB.

This issue, the so-called ‘transalpine issue’ does not reprint the three letters written to Welser by Christoph Scheiner about 1611. The two issues of the editio princeps of Istoria e dimostrazioni were published at the same time; apparently, one was meant to be distributed in Italy (where there would be no copyright dispute on Scheiner’s letters), whereas the other was tailored for export.
The edition bears a beautiful, engraved portrait of Galileo within architectural border, drawn by the famous artist Francesco Villamena (1564-1624). Two putti are representations of astronomical science: one is measuring with a compass, the other is observing the sky with a telescope.