Manual of astronomyLippincott, 1853 - 331 páginas |
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Página 24
... force of gravity were to change , the time of vibration would be altered ; for it is plain that if the intensity of attraction increased , the pendulum in every oscillation would be drawn more quickly through the arc towards a ...
... force of gravity were to change , the time of vibration would be altered ; for it is plain that if the intensity of attraction increased , the pendulum in every oscillation would be drawn more quickly through the arc towards a ...
Página 25
... force of gravity at the equator is still fur- ther weakened by the direction of the centrifugal force , which is always in the same plane as the circle of revo- lution . The direction of gravity is always towards the cen- tre of the ...
... force of gravity at the equator is still fur- ther weakened by the direction of the centrifugal force , which is always in the same plane as the circle of revo- lution . The direction of gravity is always towards the cen- tre of the ...
Página 26
... force oper- ates not in direct oppo- sition to that of grav- ity , but obliquely to it : whereas if we take a portion of the earth's surface at the equator , the centrifugal tendency will operate in the plane e c q exactly at right ...
... force oper- ates not in direct oppo- sition to that of grav- ity , but obliquely to it : whereas if we take a portion of the earth's surface at the equator , the centrifugal tendency will operate in the plane e c q exactly at right ...
Página 27
... force , and the nearer approach of the poles to the earth's centre than of the equatorial regions . The pendulum offers to us the means of determin- ing this point with great accuracy ; for by marking the number of vibrations in a given ...
... force , and the nearer approach of the poles to the earth's centre than of the equatorial regions . The pendulum offers to us the means of determin- ing this point with great accuracy ; for by marking the number of vibrations in a given ...
Página 37
... force of torsion , or the power the wire exerts to recover its original position ; from this , and from the displacement of the line of rest , viz . the angle icg , the power of the attractive force of the two spheres d and e may be ...
... force of torsion , or the power the wire exerts to recover its original position ; from this , and from the displacement of the line of rest , viz . the angle icg , the power of the attractive force of the two spheres d and e may be ...
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Términos y frases comunes
achromatic altitude angle appear ascer astronomers atmosphere attraction axis azimuth calculated celestial globe circle collimation comet correct declination density describe determine diameter difference direction disc diurnal double stars earth earth's orbit east ecliptic equal equator equatorial equinoctial error fixed stars force Greenwich heavenly body heavens Herschel horizon hour-angle hour-circle inches inclination inferior planet instrument Jupiter latitude length light longitude Mars mean measured Mercury meridian miles minutes moon moon's motion Nautical Almanac nebula nodes object object-glass observation Observatory parallax pass pendulum perihelion perpendicular planet planetary Plate point of Aries polar distance pole portion position proportion rays refraction revolution revolve round right ascension round the sun satellites Saturn seconds seen shadow shew shewn side sidereal sidereal day space sphere spherical sun's superior planet suppose surface telescope tion transit transit circle Uranus Venus vertical vibration wire
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Página 131 - Milky-way, when exploring that region with his best glasses, he has had fields of view which contained no less than 588 stars, and these were continued for many minutes; so that " in one quarter of an hour's time there passed no less than one hundred and sixteen thousand stars through the field of view of his telescope.
Página 42 - ... posterity; but the record remains, and transfuses all its own exactness into every determination which takes it for a groundwork, giving to inferior instruments — nay, even to temporary contrivances, and to the observations of a few weeks or days — all the precision attained originally at the cost of so much time, labour, and expense.
Página 178 - That the interval between the orbits of any two planets is about twice as great as the inferior interval, and only half the superior one.
Página 11 - ... it is most probably also inhabited, like the rest of the planets, by beings whose organs are adapted to the peculiar circumstances of that vast globe.
Página 1 - And yet, fair bow, no fabling dreams But words of the Most High, Have told why first thy robe of beams Was woven in the sky.
Página 42 - The stars are the landmarks of the universe ; and, amidst the endless and complicated fluctuations of our system, seem placed by its Creator as guides and records, not merely to elevate our minds by the contemplation of what is vast, but to teach us to direct our actions by reference to what is immutable in his works.
Página 180 - A plane rectilineal angle is the inclination of two straight lines to one another, which meet together, but are not in the same straight line.
Página 42 - ... and in all places, of a delicacy so extreme as to be a test for every instrument yet invented by man, yet equally adapted for the most ordinary purposes; as available for regulating a town clock as for conducting a navy to the Indies ; as effective for mapping down the intricacies of a petty barony as for adjusting the boundaries of Transatlantic empires. When once its place has been thoroughly ascertained and carefully recorded, the brazen circle with which...