DE CIRCULI MAGNITUDINE INVENTA FULL

In 1656 Huygens presented his theory in a one-sentence anagram included in Pierre Borel's De vero telescopii inventore, thus securing priority of the discovery.

'He arrived at this solution partly through the use of better observational equipment, but also by an acute argument based on the use of the Cartesian vortex (the whirl of 'celestial matter' around a heavenly body supporting its satellites)' ( DSB). Although still unable to physically make out the cause of Saturn's odd and variable shape, Huygens theorized that it was due to a single flat ring, whose inclination to the line of sight varies. In 1655, using their first greatly improved telescope, Huygens spotted a satellite of Saturn, later named Titan. Starting in the 1650s, Huygens and his brother Constantijn acquired great skill in the grinding and polishing of spherical lenses, and the telescopes that they built were the best of their time. The mystery of Saturn's 'arms' had puzzled astronomers in the decades following Galileo's observation in 1610 of the planet's oval shape.

DE CIRCULI MAGNITUDINE INVENTA FULL

Contemporary vellum (turn-ins slightly bowing).įIRST EDITION OF THE FIRST FULL ANNOUNCEMENT OF HUYGENS' DISCOVERY OF THE RING AND SATELLITE OF SATURN. One folding engraved plate, 11 engravings in text, 8 woodcut text diagrams, woodcut initials. Systema Saturnium, sive de causis mirandorum Saturni phaenomenon, et comite ejus planeta novo.

De circuli magnitudine inventa