Page:The Botany of the Antarctic Voyage.djvu/639

Ad Will he published in a few days, ftp. Sro, neat cloth, price 5*. THE PLANETARY AND STELLAR UNIVERSE. WITH NUMEROUS ASTRONOMICAL DIAGRAMS. BY EOBERT JAMES MANN. CHAPTER I. THE TELESCOPE. Invention of Instrument, First Astronomical Employment — Radiant Light — Optical Property of Lenses — Camera Obscura — The Eye — Illuminating ami Magnifying Powers of Telescope — Its Various Construction — Astronomical Refractor — Reflectors, — Gregorian, Newtonian, and Le- Mairean — The Parsonstown Leviathan. CHAPTER II. REVELATIONS OF THE TELESCOPE— THE MOON. A solid opaque Sphere of large size — Without Atmosphere or Water — Inequalities of Surface — ■ Shadows at Quadrature — Height of Projections — Explosive Craters, Tycho — Isolated Peaks — Mountain Ridges — Extended Plains — Recent Extinct Volcanoes, Copernicus, Kepler, Aristar- chus — General Conclusions. CHAPTER III. REVELATIONS OF THE TELESCOPE— THE PLANETS. Mercury — Venus, its Phases, Atmosphere, and Seasons — Mars, its Continents, Atmosphere, and Snows — the Asteroids — Jupiter, its Belt, Perpendicular Axis, and Satellites — Deduction of Rate of Propagation of Light — Saturn, its Rings and Satellites — Herschel. CHAPTER IV. REVELATIONS OF THE TELESCOPE— THE SUN. Apparent Motions of Sun — Its real Rotation — Maculae of Surface, their Nucleus and Umbra — Analogy with terrestrial atmospheric Changes — Facuhc of Surface — Solar Constitution, a Nucleus and double Atmosphere — Extension and Attenuation of outer Envelope — The Solar System as a whole. CHAPTER V. REVELATIONS OF THE TELESCOPE— THE FIXED STARS. Parallax — The Means of estimating the Distances and Dimensions of the Sun and Planets — Classification of fixed Stars — Their apparent Motions- — Arrangement in Space — Star Firma- ment — Periodic Stars — Double Stars — Their Revolution and Complementary Colours of Con- stituents — Quadruple Star — Star Clusters — Remote Star Firmaments. CHAPTER VI. REVELATIONS OF THE TELESCOPE— NEBULyE AND COMETS. Irresolvable Nebulae — Nebulous Stars — Theory of Nebular Condensation — Comets — External Characters — Intimate Constitution — Luminosity — Volume and Density — Nature of Orbits — Halley's, Encke's, Biela's, Faye's, De Vico's, Lexel's — Occasional Comets — Material ponder- able, but seat of some imponderable Elements — Sympathetic relation to Solar Sphere. CHAPTER VII. THE TELESCOPE IN THE OBSERVATORY. Man's primeval Notions of the Universe — Origin of Astronomical Observations — Progress of the Science in Chaldea, Egypt and Greece. — Pythagoras. — The barbarous and dark Ages; Astrology in Arabia, and Spain — 16th. Century ; Copernicus, Tycho Brahe. — 17th Century; Kepler, Galileo, Gascoyne, Picard, and Romer; The Transit and Mural Circle. — 18th Century Establishment of National Observatories. CHAPTER Vm. IMPORTANCE OF TELESCOPIC OBSERVATION TO THE THEORIES OF PHYSICAL ASTRONOMY. Newton ; his deductions from Kepler's Laws. — Examination of the Nature of the Deflecting Power acting upon the Moon — Picard's Measure of a Degree— Identification by it of Deflecting Force with Terrestrial Gravitations. — Extension of Principle to Investigation of Perturbations and Densities of Planets. — Adaptation of Projectile and Deflecting Forces to Elliptical Motion. Reeve, Brothers, King William Street, Strand.