Elements of Astronomy: Illustrated with Plates, for the Use of Schools and Academies, with QuestionsCummings, Hilliard & Company, 1825 - 151 σελίδες |
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Σελίδα
... greater evil to have a book remain imperfect , while it is in the power of the author to improve it , and the book is worth the labour . This is particularly true with regard to books like this . New facts in astronomy are continually ...
... greater evil to have a book remain imperfect , while it is in the power of the author to improve it , and the book is worth the labour . This is particularly true with regard to books like this . New facts in astronomy are continually ...
Σελίδα 8
... greater or smaller . This may be readily done by drawing two or three concentric circles , and a few lines from the centre to the outermost circle . 12. But the other primary planets , when seen from the sun , do not describe exactly ...
... greater or smaller . This may be readily done by drawing two or three concentric circles , and a few lines from the centre to the outermost circle . 12. But the other primary planets , when seen from the sun , do not describe exactly ...
Σελίδα 10
... greater than the hole or surface BF ; consequently , the heat and light at any point in Co , is 4 times less , than at a point in BF . But if there be a surface DS , at the distance of 3 feet , instead of Co , it will be found , that ...
... greater than the hole or surface BF ; consequently , the heat and light at any point in Co , is 4 times less , than at a point in BF . But if there be a surface DS , at the distance of 3 feet , instead of Co , it will be found , that ...
Σελίδα 13
... greater than is represented on the figure . For while Venus passes from C to D , half its orbit , the earth , instead of passing through the small portion AF , has passed through nearly of her orbit ; through which , and considerably ...
... greater than is represented on the figure . For while Venus passes from C to D , half its orbit , the earth , instead of passing through the small portion AF , has passed through nearly of her orbit ; through which , and considerably ...
Σελίδα 13
... greater than is represented on the figure . For while Venus passes from C to D , half its orbit , the earth , instead of passing through the small portion AF , has passed through nearly of her orbit ; through which , and considerably ...
... greater than is represented on the figure . For while Venus passes from C to D , half its orbit , the earth , instead of passing through the small portion AF , has passed through nearly of her orbit ; through which , and considerably ...
Άλλες εκδόσεις - Προβολή όλων
Συχνά εμφανιζόμενοι όροι και φράσεις
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
Δημοφιλή αποσπάσματα
Σελίδα 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!
Σελίδα 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.
Σελίδα 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.
Σελίδα 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...
Σελίδα 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.
Σελίδα 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.
Σελίδα 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.