Elements of Astronomy: Accompanied with Numerous Illustrations, a Colored Representation of the Solar, Stellar, and Nebular Spectra, and Celestial Charts of the Northern and the Southern Hemisphere |
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angle aphelion apparent motion apparent movements appear asteroids astronomers atmosphere attraction axis Boötes bright called celestial equator celestial pole celestial sphere centre changes circle clock color comet constellations density Describe determined diameter direction disk distance Earth Earth's orbit Earth's rotation Earth's surface equal equatorial eye-piece fact globe gravity heat heavenly body heavens hemisphere Hence horizon inclined inferior planet Jupiter latitude length lens light longitude lunar magnitude Mars mass mean Sun Mercury meridian meteors miles Moon Moon's move naked eye nearest nearly nebula Neptune night node northern object-glass observed parallax path perihelion period photosphere polar position prism rays refraction represented revolution revolve round right ascension ring round the Sun satellites Saturn seen shadow sidereal solar day solstice southern spectrum spots stars Sun's superior planet suppose tance telescope tion Uranus Ursa vapor variable stars velocity Venus vernal equinox visible zenith zenith-distance
Popular passages
Page 20 - A Circle is a plane figure bounded by a curved line every point of which is equally distant from a point within called the center.
Page 20 - Every circumference of a. circle, whether the circle be large or small, is supposed to be divided into 360 equal parts called degrees. Each degree is divided into 60 equal parts called minutes, and each minute into 60 equal parts called seconds.
Page 22 - A Sphere is a solid bounded by a curved surface every point of which is equally distant from a point within, called the centre. A Hemisphere is half a sphere. A Diameter of a sphere is a straight line passing through its centre, and terminating at each end in its surface.
Page 153 - A man placed on one of them would spring with ease 60 feet high, and sustain no greater shock in his descent than he does on the earth from leaping a yard.
Page 130 - Moon's shadow sweeps across the surface of the Earth, and is even seen in the air; the rapidity of its motion and its intenseness produce a feeling that something material is rushing over the Earth at a speed perfectly frightful.
Page 257 - ... alteration of some four millions of miles in the Sun's reputed distance from our Earth, this misgiving may, perhaps, be removed by the consideration that after all this improvement of our knowledge amounts to no more than a correction to an observed angle represented by the apparent breadth of a human hair viewed at the distance of about 125 feet.] * Before 1769, astronomers had endeavoured to determine the distance of the Sun in various ways.
Page 171 - These afterwards collected together into larger masses, which have been variously changed by subsequent metamorphic action, and broken up by repeated mutual impact, and often again collected together and solidified. The meteoric irons are probably those portions of the metallic constituents which were separated from the rest by fusion when the metamorphism was carried to that extreme point.
Page 235 - Bearing in mind that what an astronomer wants is a good clear image of the object observed, we shall at once recognise that magnifying power depends upon the perfection of the image thrown by the object-glass and upon the illuminating power.
Page 54 - ... proof that the object consists of true stars. These luminous points, in some nebulae at least, must be regarded as themselves gaseous bodies, denser portions, probably, of the great nebulous mass, since they exhibit a constitution which is identical with the fainter and outlying parts which have not been resolved. These...
Page 2 - ... Composition and Rhetoric. A Series of Practical Lessons on the Origin, History, and Peculiarities of the English Language, Punctuation, Taste, the Pleasures of the Imagination, Figures, Style, Criticism, and Prose and Poetical Composition, with Exercises. New and revised edition.