A Treatise on Astronomy: Illustrated with Maps and PlatesE. Hunt & Company, 1837 - 288 sider |
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Resultat 1-5 av 33
Side 25
... poles of the earth are the two points on its surface where its axis terminates ; that nearest the United States is the north pole , that most distant the south pole . In fig . 5 , N represents the former , and S the latter . Similarly , the ...
... poles of the earth are the two points on its surface where its axis terminates ; that nearest the United States is the north pole , that most distant the south pole . In fig . 5 , N represents the former , and S the latter . Similarly , the ...
Side 28
... north pole be elevated , and from the south point , if the south pole be elevated , ) referred to the horizon for measure- ment by a vertical circle , passing through the centre of the body , is called its azimuth . If N represent the ...
... north pole be elevated , and from the south point , if the south pole be elevated , ) referred to the horizon for measure- ment by a vertical circle , passing through the centre of the body , is called its azimuth . If N represent the ...
Side 31
... north pole , at any place north of the equa- tor , equals the latitude of that place , ( as will be demon- strated in the succeeding chapter . ) The latitude of Boston is about 42 degrees , the north pole then , observ . ed from Boston ...
... north pole , at any place north of the equa- tor , equals the latitude of that place , ( as will be demon- strated in the succeeding chapter . ) The latitude of Boston is about 42 degrees , the north pole then , observ . ed from Boston ...
Side 32
... north at k , will only just touch the horizon when at its lowest point as seen from B , and its whole course klom will be above the horizon ; and the same is true of all the stars lying between this circle and the north pole N. These ...
... north at k , will only just touch the horizon when at its lowest point as seen from B , and its whole course klom will be above the horizon ; and the same is true of all the stars lying between this circle and the north pole N. These ...
Side 33
... pole N , the smallest . Were a star exactly in the north pole N , it would be ( so far as this motion is concerned ) , perfectly stationary . The star called the pole star ( see the Northern Circumpo- lar map ) , is nearest this point ...
... pole N , the smallest . Were a star exactly in the north pole N , it would be ( so far as this motion is concerned ) , perfectly stationary . The star called the pole star ( see the Northern Circumpo- lar map ) , is nearest this point ...
Vanlige uttrykk og setninger
altitude amount angle angular distance apogee apparent diameter apparent magnitude ascertained astronomers attraction called cause celestial pole celestial sphere centre of gravity circle comet consequently constellation cresent declination degrees described difference Digits eclipsed direction earth earth's axis earth's orbit earth's shadow earth's surface east ecliptic limit equal equator equinoctial evident explain fig FIGURE greater greatest heavenly body heavens hemisphere Herschel horizon illustrated by fig increases Jupiter latitude latter length less libration light longitude lunar eclipse magnitude mean solar meridian miles months moon moon's disc moon's orbit moving nearly nebulæ node north pole obliquity observed parallax pass perigee period plane Planisphere position precession radius represent retrograde retrograde motion revolve right ascension rising rotation Saturn seen side sidereal sidereal day solar days solar eclipse stars stationary sun's supposed synodic revolution take place tides tion variation velocity Venus vernal equinox visible zenith
Populære avsnitt
Side 142 - Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Virgin, Libra the Balance, Scorpio the Scorpion, Sagittarius the Archer, Capricornus the Goat, Aquarius the Waterbearer, and Pisces the Fishes...
Side 163 - On the other hand, in the regions beneath the dark side, a solar eclipse of fifteen years in duration, under their shadow, must afford (to our ideas) an inhospitable asylum to animated beings, ill compensated by the faint light of the satellites. But we shall do wrong to judge of the fitness or unfitness of their condition from what we see around us, when, perhaps, the very combinations which convey to our minds only images of horror, may be in reality theatres of the most striking and glorious displays...
Side 165 - 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, in a circle nearly half a mile across...
Side 20 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds.
Side 228 - In the solitude of the seas, we hail a star as a friend from whom we have long been separated. Among the Portuguese and the Spaniards peculiar motives seem to increase this feeling; a religious sentiment attaches them to a constellation, the form of which recalls the sign of the faith planted by their ancestors in the deserts of the New World.
Side 228 - It has been observed at what hour of the night, in different seasons, the Cross of the South is erect or inclined. It is a time-piece that advances very regularly near four minutes a day, and no other group of stars exhibits, to the naked eye, an observation of time so easily made.
Side 248 - Thus a yellow colour predominating in the light of the brighter star, that of the less bright one in the same field of view will appear blue ; while, if the tint of the brighter star verge to crimson, that of the other will exhibit a tendency to green — or even appear as a vivid green, under favourable circumstances.
Side 54 - If from any point without a circle two straight lines be drawn, one of which cuts the circle, and the other touches it ; the rectangle contained by the whole line which cuts the circle, and the part of it without the circle, shall be equal to the square of the line which touches it.
Side 165 - ... 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, in a circle nearly half a mile across; Saturn a small orange, on a circle of four-fifths of a mile...
Side 248 - In such instances, the larger star is usually of a ruddy or orange hue, while the smaller one appears blue or green, probably in virtue of that general law of optics, which provides, that when the retina is under the influence of excitement by any bright, coloured light ; feebler lights, which seen alone would produce no sensation but of whiteness, shall for the time appear coloured with the tint complementary to that of the brighter.