HUYGENS, Christiaan (1629-1695). Systema Saturnium, sive de causis mirandorum Saturni phaenomenon, et comite ejus planeta novo. The Hague: Adrian Vlacq, 1659.
4o (191 x 140 mm). One folding engraved plate, 11 engravings in text, 8 woodcut text diagrams, woodcut initials. (First and last leaves slightly soiled and foxed, marginal discoloration throughout, small wormtrack in gutters, catching a few letters in quires C and D, slight fraying to edges of last 2 leaves.) Contemporary blind-panelled calf (rebacked, worn).
FIRST EDITION of the first full announcement of Huygens' discovery of the ring and satellite of Saturn. The mystery of Saturn's "arms" had puzzled astronomers in the decades following Galileo's observation in 1610 of the planet's oval shape. 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. In 1655, using their first greatly improved telescope, Huygens spotted a satellite of Saturn, later named Titan. 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. "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). In 1656 Huygens presented his theory in a one-sentence anagram included in Pierre Borel's De vero telescopii inventore (see lot 311), thus securing priority of the discovery. The Systema Saturnium contains as well "many other observations on the planets and their satellites, all contributing to an emphatic defense of the Copernican system", and an observation and illustration of the Orion nebula. Dibner Heralds of Science 9; Norman 1136.
HUYGENS. "Nouvelle invention d'un niveau a lunette qui porte sa preuve avec soi, & que l'on vrifie & rectifie d'un seul endroit" [Extract from: Journal des savans. Paris: chez Jean Cusson, 1680]. 4o, 2 conjugate leaves, signature F2, with title-leaf from the Journal. Engraved text illustration. (Light foxing.) A description of one of the Huygens' telescopes, this one with an attached levelling device. Norman 1138. (2)