The Elements of Astronomy: A TextbookGinn, 1903 - 464 стор. |
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Загальні терміни та фрази
altitude Andromeda angle apparent astronomical astronomical units atmosphere attraction axis Boötes bright lines Cassiopeia celestial equator celestial sphere centre chromosphere circle comet constellation corona dark declination density determine diameter disc Dist distance Double Stars earth earth's orbit earth's surface east eclipse equal equatorial eye-piece feet force globe gravity heat heavenly bodies horizon inches instrument Jupiter known latitude light longitude lunar magnitude Mags mass mean measured meridian meridian circle meteoric method minutes moon moon's motion moving naked eye nearly nebula node object object-glass observations Ophiuchus orbit parallax perihelion period perturbations photographs photosphere planet pole Pole-star probably radius right ascension ring rotation satellites seen shadow sidereal sidereal period Sirius solar spectra spectroscope spectrum spots sun's synodic synodic period telescope tides tion transit Uranus Ursa velocity Venus vernal equinox visible zenith
Популярні уривки
Сторінка 18 - ... is the great circle in which the plane of the earth's equator cuts the celestial sphere (Fig. 6). It is often called the Equinoctial.
Сторінка 172 - The radius vector of each planet describes equal areas in equal times. (3) The squares of the periods of the planets are proportional to the cubes of their mean distances from the su» ; ie, £12 : ia2 : : «!3 : a28. This is the so-called "Harmonic Law.
Сторінка 383 - Without stopping to prove the principle, we may say that the magnifying power is simply equal to the quotient obtained by dividing the focal length of the object-glass by that of the eye-lens; or, as a formula M = — ; that is, — in the figure.
Сторінка 211 - On it place a globe, two feet in diameter; this will represent the Sun; Mercury will be represented by a grain of mustard seed, on the circumference of a circle 164 feet in diameter for its orbit; Venus a pea, on a circle 284 feet in diameter; the Earth also a pea, on a circle of 430 feet; Mars a rather large pin's head, on a circle of 654 feet; Juno, Ceres, Vesta, and Pallas, grains of sand, in orbits of from 1000 to 1200 feet; Jupiter a moderate-sized orange...
Сторінка 69 - ... prehistoric times, and have received fanciful names. Sometimes the arrangement of the stars bears a resemblance to the object after which the constellation is named; in general, however, no reason can be given for the way in which the stars have been grouped and named.
Сторінка 224 - The inclination of the planet's equator to the plane of its orbit is very nearly 24° 50' (26° 21
Сторінка 75 - The obliquity of the ecliptic, which equals the angular distance of the pole of the heavens from the pole of the ecliptic, is not sensibly affected by precession.
Сторінка 146 - which is the quantity of heat required to raise the temperature of one kilogram of water 1° C. ; and as the result of the best observations thus far made, it appears that the solar constant is between 25 and 30 of these "calories...
Сторінка iv - The eminence of Professor Young as an original investigator in astronomy, a lecturer and writer on the subject, and an instructor in college classes, led the publishers to present the General Astronomy with the highest confidence; and this confidence has been fully justified by the event.