Degree of meridian, how measured, 210. Diameter* of the earth, 220, 221. Of Dilatation of comets in receding from Diane, 548. Discs of stars, 816. Distance of the moon, 403.; the sun, Districts, natural, in heavens, 302. Disturbing forces, nature of, 609... Ge- Diurnal motion explained, 58. Paral- Double refraction, 202. Image micro- Double Start, 833... Specimens of each Dove, his law of temperature, 370. E. Earth. Its motion admissible, 15. Eclipses, 411... Solar, 420. Lunar, 421 Ecliptic, 305... Its plane slowly vari- Egyptians, ancient, their chronology, Elements of a planet's orbit, 493. Va- Ellipse, variable, of a planet, 653. Mo- Elliptic motion a consequence of gravi- Elliplicity of the Earth, 221. Elongation, 341. Greatest, of Mercury Enceladus, 548., note. Encke, comet of, 576. His hypothesis Epoch, one of the elements of a planet's Equation of light, 335. Of the center, Equator, 84. Equatorial, 185. Equilibrium, figure of, in a rotating Equinoctial, 97. Time, 935. E<piinox, 293. 303. Equinoxes, precession of, 312. Its ef- Eras, chronological list of, 926. Errors, classification of, 133. Instru- Establishment of a port, 754. Ether, resistance of, 577. Eviction of moon, 748. Excentricities, stability of Lagrange's Excentricitg of earth's orbit, 354. How F. Facula, 338. Faye, comet of, 584. and Appendix. Flora, discovery of, 505. Focus, upper. Its momentary change of place, 670, 671. Path of, in virtue Force, metaphysical conception of, 439. Forced vibration, principle of, 650. Forces, disturbing. Sec Disturbing force. G. Galaxy composed of stars, 302. Sir place indicated by theory, 768. proper motion, 855. planet (Appendix). 497. 247... stars, 821... H. Hattey. IBs comet, 567. First notices Hansen. His detection of long ine- Harding discovers Juno, 505. Heat, supply of, from sun alike in Hebe, discovery of, 505. Heights above the sea, how measured, Heliocentric place, 500. Ilelio meter, 201. Hemispheres, terrestrial and aqueous^*. Herschd, Sir Wm., discovers Uranus, Horizon, 22. Dip of, 23. 195. Ratioiul Horizontal point of a mural circle, how i/our circles, 106.; angle, 107.; gUs*. Hyperion, Appendix, Saturn's satellites. lapetus, 548. Inclination of tho moon's orbit, 406. Of Inclinations, stability of, Lagragc's theo- Inflictions, 923. Inequality, Parallactic of moon, 712. Inequalities, independent of execntri- Intercalation, 916. Irix, discovery of, 505. Iron, meteoric, 888. J. Juliar. period, 924. Date, 930. Re- Juno, discovery of, 505. Jupiter, physical appearance and de- Jupiter and Saturn, their mutual per- Kater, his mode of measuring small in- Kepler, his laws, 352. 487. 489. Their Lagging of tides, 753. Lagrange, his theorems respecting the Laplace accounts for the secular accele- Lassell, his discovery of the satellite of Latitude, terrestrial, 88. Parallels of, Laws of nature how arrived at, 139. Level, spirit, 170. Sea, 285. Strata,287. Leverrier, 506, 507. 767. Lexell, comet of, 585. Libratum of the moon, 435. Of ap- Light, aberration of, 331. Velocity of, Local time, 252. London, centra of the terrestrial hemi- Longitude, terrestrial, 90. How deter- Lunation (synodic revolution of the M. Magellanic clouds, 892... Magnitudes of stars, 780... Common Maps, geographical, construction of, 273. Mars, phases of, 484. Gravity on sur- Masses of planets determined by their Menstrual equation, 528. Mercator's projections, 283. Mercury, synodic revolution of, 472. Meridian, terrestrial, 85. Celestial, 101. Messier, his catalogue of nebuke, 865. Meteors,S9S. Periodical,900... Heights Metis, discovery of, 605. Micrometers, 199... Milky way. {See Galaxy, 302.) Mimas, 550., and note. Mira Ceti, 820. Moon, her motion among the stars, 401. Motion, apparent and real, 15. Diurnal, Mountains, their proportion to the globe, Mowna Roa, 32. Mural circle, 168. N. Nabonassar, era of, 926. Nadir, 99. Nebulae, classifications of, 868.879., note. Nebular hypothesis, 872. Nebulous matter, 871. Stars, 880. Neptune, discovery of, 506. 768. Per- Newton, his theory of gravitation, 490... Nodes of the sun's equator, 390. Of Nomenclature of Saturn's satellites, 5*8, Nonagesimal point, how found, 310. Normal disturbing force and its effects, Nubecula, major and minor, 892... Number, golden, 922. Nutation, in what consisting, 321. Period, 322. Common to all celestial bodies, 323. Explained on physical prin- O. Obliquity of ecliptic, 303. ProdocM Observation, astronomical, its peculiari- Occultation, perpetual, circle of, 113. Olbcrs discovers Pallas and Vests, 505. Opacity, partial, of space, 798. Oscillations, forced, principle of, 650. Orbits of planets, their elements (Ap- Ortliogonal disturbing force, and ia Orthograpluc projection, 280. P. Politick discovers the variability of Pallas, discovery of, 505. Parallactic instrument, 185. Inequality Parallax, 70. Geocentric ox diurai, Peak of Teneriffe, 32. Pendulum-clock, 89. A measure d Penumbra, 420. Perigee of moon, 406. PeriheTta and excontricitics, theory of, Perihelion, 368. Longitude of, 495. Period, Julian, 924. Of planets (App.). Periodic time of a body revolving at the Periodical stars, 820... List of, 825. Perspective, celestial, 114. Perturbations, 602... Peters, his researches on parallax, 815. Phases of the moon explained, 416. Of Photometric scale of star magnitudes, 780. Piazzi discovers Ceres, 505. Pioott, variablo stars discovered by, Places, mean and true, 374. Geometric Planetary nebula;, 876... Planets, 456. Zodiacal and ultra-zo- Plantamour, his calculations respecting Pleiades, 865. Assigned by Midler Plumb-line, direction of, 23. Use of, in Polar distance, 105. Point, on a mural Poles, 83. Of ecliptic, 307. Pole-star, 59. Useful for finding the Pores of the sun's surface, 387. Position, angle of, 204. Micrometer, ib. Precession of the equinoxes, 312 In what consisting, 314... Effects, 313. Physical explanation, 642... vibrations, 650. Of repetition, 198. Of conservation of vis viva, 663. Of collimation, 178. 309... 414., note. the sun, 853. Radial disturbing force, 615... Radiation, solar, on planets, 508. On Rate of clock, how obtained, 293. Reading off, methods of, 165. Reflexion, observations by, 173. Refraction, 38. Astronomical and its Repetition, principle of, 198. Resistance of ether, 577. Rctrogradations of planets, 459. Of Rhea, 548., note. Right ascension, 108. How determined, Rings of Saturn, dimensions of, 514. Rittenhouse, his principle of collimation, . 178. Ros.w, Earl of, his great reflector, 870. Rotation, diurnal, 58. Parallactic, 68. Soros, 426. Satellites, of Jupiter, 511. Of Saturn, |