|List of Figures and Illustrations: Systema Saturnium by Christiaan Huygens|
|6||Huygens's 1656 observations of bands on Jupiter (top two) and Mars (bottom).|
|8||Huygens's 1656 observation of the nebulosity in the sword of Orion (now called the Great Nebula in Orion or M42).|
|9, 11-17, 19-25||Huygens's series of observations of Saturn and its satellite [Titan] from 1655 to 1659.|
|10||Huygens's March 1655 observation of Saturn showing how he saw Saturn's "arms" (as he called the extensions) to be a little thicker at their ends than where they were "attached" to the planet.|
|11||Huygens's 1656 observation of Saturn with a larger telescope (23 feet focal length) than before showing the "arms" and a shadow across the planet that joins the two arms.|
|16||Huygens's observation of Saturn in early 1656 when the planet's "arms" were not visible.|
|18||Huygens's observation of Saturn on October 13, 1656, showing the form he predicted it would have.|
|21||Huygens's observation of Saturn on December 17, 1657, showing the "arms" open as if they were handles, the first time he had seen them that way.|
|24||Huygens's observation of Saturn on February 12, 1659, showing the "handles" (his new term for the appendages) more open than before.|
|27||Diagram of a representation of the orbit of the satellite [Titan] with Saturn at the center.|
|28||Diagram of the orbits of the Earth (GF), Saturn (ABC), and the satellite [Titan] around Saturn (NHK and DEL). The Sun is at the center (S).|
|Plate between pages 32-33||Observations of Saturn by others prior to Huygens. I is an observation by Galileo in 1610. II is one by Scheiner in 1614. III is one by Riccioli from 1641-1643. IV-VII represent suggestions by Hevelius based on his theories. VIII and IX are observations by Riccioli from 1648-1650. X is an observation by Divini from 1646-1648. XI is one by Fontana in 1636. XII is one by Gassendi in 1646. XIII is from observations by Fontana and others from 1644-1645.|
|47||Huygens's concept of the actual form of Saturn and its ring.|
|49||Diagram of the relation of the path of Saturn (ADC) to that of the ecliptic and the ring plane (EC) on March 25-27, 1655.|
|50 ||Top: Diagram of the relation of the path of Saturn (LMNO) to that of the
ecliptic (RQ) and the ring plane (POQ) on April 9-12, 1655.
Bottom: Diagram of the relation of the path of Saturn (ST) to that of the ecliptic (XY) and the ring plane (VSX) on May 27 and 31, 1655.
|51||Diagram of Saturn as seen in the telescope's field of view on October 13, 1656, indicating how the planet travels in the same direction as the rings.|
|55||Top: Diagram showing how Saturn's appearance to us changes due the
changing positions of the Earth (E) and Saturn as they orbit the Sun (G).
Bottom: Huygens's observation of Saturn presenting its rings to us at their greatest inclination.
|60||Repeat of figure at top of page 55.|
|63||Diagram of the orbit of Saturn (ANC) and the Earth (DEF) around the Sun (L) for the purposes of describing how Saturn's rings will vanish and produce Saturn's "round phase."|