Elements of Astronomy: Illustrated with Plates, for the Use of Schools and Academies, with Questions |
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Page 44
... rising and setting of the sun , and of stars near the equator . 78. Hence it is often desirable to correct timepieces at sea ; and for this purpose eclipses of the moon are sometimes of use . For eclipses of the moon take place at ...
... rising and setting of the sun , and of stars near the equator . 78. Hence it is often desirable to correct timepieces at sea ; and for this purpose eclipses of the moon are sometimes of use . For eclipses of the moon take place at ...
Page 51
... rising and setting of the sun , and of stars near the equator . 78. Hence it is often desirable to correct timepieces at sea ; and for this purpose eclipses of the moon are sometimes of use . For eclipses of the moon take place at ...
... rising and setting of the sun , and of stars near the equator . 78. Hence it is often desirable to correct timepieces at sea ; and for this purpose eclipses of the moon are sometimes of use . For eclipses of the moon take place at ...
Page 69
... rising would be one hour . But the moon is 29 days in passing from change to change ; consequently her mean daily motion is , ( 360 - 291 ) 12 ° 12 ' 12 ' ' , and of course the mean difference in the times of her rising is something ...
... rising would be one hour . But the moon is 29 days in passing from change to change ; consequently her mean daily motion is , ( 360 - 291 ) 12 ° 12 ' 12 ' ' , and of course the mean difference in the times of her rising is something ...
Page 70
... rising is very small ; but while successively in the points a , b , c , & c . the difference in the times of rising is very great . This subject may be illustrated much more clearly by a globe than by any representation on paper . By ...
... rising is very small ; but while successively in the points a , b , c , & c . the difference in the times of rising is very great . This subject may be illustrated much more clearly by a globe than by any representation on paper . By ...
Page 71
... rising is there least when the moon is in or near Libra ; hence their harvest moon comes when the sun is in or near Aries , that is , in our spring . But our spring is their autumn ; so that they derive the same advantages from them ...
... rising is there least when the moon is in or near Libra ; hence their harvest moon comes when the sun is in or near Aries , that is , in our spring . But our spring is their autumn ; so that they derive the same advantages from them ...
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Common terms and phrases
angles appear Aries ascertained astronomers attraction axis beginning Boston called cause celestial equator centre circle comes comets complete consequently constellations course Cross dark declination describe direction distance divided east eastward eclipses effect equal example explain fall figure force given globe greater greatest half heat heavenly bodies heavens hemisphere Hence horizon hour Illustrate inhabitants Jupiter known latitude length less Letter light London longitude Mars mean meridian method miles minutes months moon moon's motion move nearly night node noon observed obvious opposite orbit passing period planets poles primary rays reckoned regions represented revolve round rise round the earth round the sun satellites Saturn secondary Sect seen shadow side solar sometimes stars sun's supposed surface TABLE turns Venus visible zenith
Popular passages
Page 16 - 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. How often have we heard our guides exclaim in the savannahs of Venezuela, or in the desert extending from Lima to Truxillo, 'Midnight is past, the Cross begins to bend!
Page 16 - We saw distinctly, for the first time, the cross of the south, only in the night of the 4th and 5th of July, in the sixteenth degree of latitude. It was strongly inclined, and appeared, from time to time, between the clouds, the centre of which, furrowed by uncondensed lightnings, reflected a silver light. The pleasure felt on discovering the southern cross was warmly shared by such of the crew as had lived in the colonies.
Page 16 - The two great stars which mark the summit and the foot of the Cross having nearly the same right ascension, it follows hence, that the constellation is almost perpendicular at the moment when it passes the meridian.
Page 57 - Passing on, he was struck with surprise at seeing a spot of ground which he knew to have been recently turfed over, all torn up, and the earth looking fresh, as if from recent violence. Coming to the place, he found a great mass of fragments of a strange looking stone, and immediately called for his wife, who was second on the ground. Here were exhibited the most striking proofs of violent ^collision. A ridge of micaceous schistus lying nearly even with the ground, and somewhat inclining like the...
Page 59 - The cycle of the moon, чиЬ«т. commonly called the golden number, is a revolution of 19 years ; in which time, the conjunctions, oppositions, and other aspects of the moon, are within an hour and a half of being the same as they were on the same days of the months 19 years before.
Page 17 - Let us return to the consideration of terrestrial latitude and longitude. As the latitude of a place is its distance from the equator measured on its meridian, and all meridians are great circles and consequently equally large, it is obvious that a degree, or ^-J^ part, of one is equal to the same part of another.
Page 57 - Bonpland relates, that from the beginning of the phenomenon there was not a space in the firmament equal in extent to three diameters of the moon, that was not filled at every instant. with bolides and falling stars.